Transcatheter device for interatrial anastomosis

Abstract

To provide a device assembly and a method for treating heart failure by normalizing an elevated blood pressure in the left atrium of the heart of a mammal.SOLUTION: Disclosed herein is a transcatheter interatrial septum excision device assembly configured to create a sized interatrial aperture between right and left atria of a heart for relief of an elevated left atrial pressure. The device assembly comprises a delivery catheter, a tissue stabilizer attached to a first catheter having a central lumen and a penetrating tip that permits passage of a guidewire, and a cutter attached to a second catheter having a central lumen that permits passage of the first catheter. Alternative configurations comprise a (third) catheter having a central lumen that permits passage of the components to and from the right atrium, a tissue retention mechanism, and an optional coaxial alignment mechanism.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] cross reference This application claims the benefit of U.S. Provisional Application No. 62 / 457,605, filed February 10, 2017, U.S. Provisional Application No. 62 / 473,027, filed March 17, 2017, U.S. Provisional Application No. 62 / 532,223, filed July 13, 2017, and U.S. Provisional Application No. 62 / 558,178, filed September 13, 2017, which are incorporated herein by reference. [Background technology]

[0002] Congestive heart failure (CHF) is a chronic condition that affects 6 million people in the United States and 23 million people worldwide. Its incidence is expected to rise over the next decade, with 650,000 new cases diagnosed annually in the United States. Once a patient is diagnosed with CHF, the expected 5- and 10-year survival rates are 50% and 10%, respectively. Heart failure is the most common cause of hospitalization in patients over 65 years of age in the United States, accounting for nearly 1 million hospitalizations each year, a figure that is expected to rise significantly. Thus, heart failure remains a major epidemic with enormous associated medical costs. Summary of the Invention

[0003] Provided herein is a device assembly (alternatively referred to herein as a transcatheter device for interatrial anastomosis assembly) configured to create a defined opening between the right and left atria of a mammalian heart to alleviate elevated left atrial pressure. In some embodiments, the opening is sized to prevent closure so that it becomes a permanent opening without the need for a mechanical support, such as a stent, to keep the opening open after the opening creation procedure. In some embodiments, the opening is sized to prevent closure so that it becomes a permanent opening without the need for a drug to prevent closure of the opening during the healing process. Disclosed herein is a transcatheter atrial septum ablation device assembly (alternatively referred to herein as a device assembly, or an ablation device assembly) configured to create a sized interatrial opening between the right and left atria of a mammalian heart to alleviate elevated left atrial pressure. The ablation device assembly includes a delivery catheter, a tissue stabilizer attached to a first catheter having a central lumen and a piercing tip that permits passage of a guidewire, and an expandable cutter attached to a second catheter having a central lumen that permits passage of the first catheter. In some embodiments, the arrangement comprises a third catheter having a central lumen permitting passage of the aforementioned components to and from the right atrium, a tissue retention mechanism, and an optional coaxial alignment mechanism.

[0004] A device assembly for treating heart failure is disclosed herein, comprising: a delivery catheter having a central delivery lumen; a first inner coaxial catheter having a first lumen that slidably engages within the central delivery lumen of the delivery catheter; an expandable tissue stabilizer attached to the first inner coaxial catheter at or near the distal end and disposed along the exterior length of the first inner coaxial catheter; a second inner coaxial catheter having a second lumen that slidably engages over the first inner coaxial catheter and within the central delivery lumen of the delivery catheter; and an expandable cutter attached and disposed along the exterior length of the second inner coaxial catheter and configured to slidably traverse or engage within the central delivery lumen of the delivery catheter. In some embodiments, the first inner coaxial catheter having a first lumen further comprises a needle-like puncture tip configured to penetrate the atrial septum. In some embodiments, the device assembly further comprises a coaxial guidewire that can be slidably engaged within the first lumen of the first inner coaxial catheter. In some embodiments, the cutting size of the expandable cutter is adjustable in situ. In some embodiments, the size of the expandable tissue stabilizer is adjustable in situ. In some embodiments, the coaxial guidewire is configured to extend from the distal end of the first lumen of the first inner coaxial catheter and pass through an initial puncture site in the interatrial septum between the right and left atria of the mammalian heart approximately at the fossa ovalis to provide a working track for the device assembly into the left atrium. In some embodiments, the distal end of the first inner coaxial catheter is configured to traverse along the guidewire trajectory and pass through the initial puncture site in the interatrial septum such that the tissue stabilizer also extends beyond the interatrial septum into the left atrium. In some embodiments, the dimensions of the tissue stabilizer are large enough to prevent it from being pulled back through the original puncture site, and the tissue stabilizer is expanded coaxially within the left atrium such that the tissue stabilizer provides a supportive tensioning effect against the wall of the atrial septum surrounding the original puncture site.In some embodiments, the second inner coaxial catheter extends relative to the delivery catheter such that the expandable cutter is slidably advanced and coaxially expanded to a cutting dimension greater than the expanded dimension of the tissue stabilizer. In some embodiments, the second inner coaxial catheter extends further until the fully expanded cutter engages or traverses the right atrial side of the interatrial septum at or around the fossa ovalis, where the cutter cuts completely through the interatrial septum, thereby forming an interatrial pressure relief opening in the interatrial septum, wherein the interatrial pressure relief opening is large enough to allow blood flow from the left atrium to the right atrium through the pressure relief opening such that no more than 50% of the blood in the left atrium is shunted to the right atrium. In some embodiments, the interatrial pressure relief opening comprises a diameter of about 8 mm, in a range of about 3 mm to about 14 mm, in a range of about 5 mm to about 12 mm, in a range of about 6 mm to about 10 mm, or in a range of about 7 mm to about 9 mm. In some embodiments, the interatrial pressure relief opening is about 50 mm. 2 In some embodiments, the interatrial pressure relief opening comprises an area of ​​about 30 mm 2 ~about 70mm 2 In some embodiments, the interatrial pressure relief opening comprises an area of ​​up to 200 mm 2 , maximum approx. 180mm 2 , maximum approx. 160mm 2 , maximum approx. 140mm 2 , up to about 120mm 2 , up to about 100 mm 2 , up to about 80mm 2 , up to about 60 mm 2 , up to about 40 mm 2 , up to about 20 mm 2 , up to about 10 mm 2 , up to about 5 mm 2 , about 5mm 2 ~about 10mm 2 , about 5mm 2 ~about 20mm 2 , about 10mm 2 ~about 20mm 2 , about 15 degrees ~ about 30 mm 2 , about 20mm2 ~ approx. 40mm 2 , about 30mm 2 ~about 45mm 2 , about 35mm 2 ~ approx. 50mm 2 , approx. 40mm 2 ~about 60mm 2 , about 45mm 2 ~about 70mm 2 , about 60mm 2 ~about 80mm 2 , about 70mm 2 ~about 90mm 2 , about 80mm 2 ~Approx. 110mm 2 , about 90mm 2 ~approx. 130mm 2 , about 100 mm 2 ~about 150mm 2 , about 35mm 2 ~65mm 2 , approx. 40mm 2 ~75mm 2 , about 45mm 2 ~80mm 2 , about 50 mm 2 ~85mm 2 , about 20mm 2 ~60mm 2 , about 30mm 2 ~80mm 2 , or about 35 mm 2 ~65mm 2In some embodiments, the inter-atrial pressure relief opening is sufficiently large and shaped to slow the natural healing process of tissue to maintain patency of the inter-atrial pressure relief opening in the atrial septum without implanting a stent, mechanical implant, or valve therein. In some embodiments, the inter-atrial pressure relief opening is sufficiently large and shaped to slow the natural healing process of tissue to maintain patency of the inter-atrial pressure relief opening in the atrial septum without implanting a stent, mechanical implant, or valve therein. In some embodiments, the inter-atrial pressure relief opening is sufficiently large or shaped to slow the natural healing process of tissue to maintain patency of the inter-atrial pressure relief opening in the atrial septum without implanting a stent, mechanical implant, or valve therein. In some embodiments, the interatrial pressure relief opening is sufficiently large and shaped to slow the natural tissue healing process to maintain the patency of the interatrial pressure relief opening in the atrial septum without mechanical support (e.g., stents, shunts, or valves) and without the local delivery of anti-proliferative or anti-inflammatory drugs to the tissue surrounding the pressure relief opening. In some embodiments, the interatrial pressure relief opening is sufficiently large or shaped to slow the natural tissue healing process to maintain the patency of the interatrial pressure relief opening in the atrial septum without mechanical support (e.g., stents, shunts, or valves) and without the local delivery of anti-proliferative or anti-inflammatory drugs to the tissue surrounding the pressure relief opening. In some embodiments, the interatrial pressure relief opening is any of the following: circular shape; oval shape; triangular shape; square shape; rectangular shape; diamond shape; polygonal shape; or any irregular shape. In some embodiments, the interatrial pressure relief opening is a three-dimensional irregular shape. In some embodiments, the cross-section of the interatrial pressure relief opening is either circular; oval; triangular; square; rectangular; diamond; polygonal; or any irregular shape.In some embodiments, the device assembly further comprises a coaxial alignment component. In some embodiments, the coaxial alignment component is configured to provide centralization between the cutter and the tissue stabilizer. In some embodiments, the tissue stabilizer comprises: an inflatable balloon; an expansion tine; an expansion mesh; at least one bent wire; an expansion plate; an expansion disk; an expansion fan; a spring coil; at least one strut; at least one hinge arm; an umbrella stretcher; or a combination thereof. In some embodiments, the tissue stabilizer material for anything other than the inflatable balloon comprises a shape memory alloy including nickel-titanium, copper-aluminum-nickel, zinc-gold-copper, or a combination thereof. In some embodiments, the cutter material comprises a shape memory alloy including nickel-titanium, copper-aluminum-nickel, zinc-gold-copper, or a combination thereof. In some embodiments, the cutter comprises: a wire mesh; a wire connecting sharp teeth; a foldable crown saw structure; a foldable open-ended cylindrical structure; a foldable open-ended barrel structure; a foldable open-ended cone structure; or a combination thereof. In some embodiments, the cutter is configured such that the cutting teeth of the cutter comprise: a single wire with a sharp point; a single-edged shape; a double-edged shape or a double-edged scissor blade; an inverted "v" shape; or a "u" shape (or a wavy shape); where the distal ends of all the teeth are cutting points and the cutting edges of the cutting teeth are configured, when combined, to cut a complete opening as the cutter passes completely through the atrial septum. In some embodiments, the cutter is configured to make an opening or hole, and the opening or hole is a circular shape; an oval shape; a triangular shape; a square shape; a rectangular shape; a polygonal shape; or a combination thereof. In some embodiments, the expanded dimension of the tissue stabilizer is less than the expanded dimension of the cutter. In some embodiments, the expanded dimension of the cutter is about 1% to about 50% greater than the expanded dimension of the tissue stabilizer.In some embodiments, the expanded dimension of the cutter is about 0.1% to about 10% greater than the expanded dimension of the tissue stabilizer. In some embodiments, the expanded dimension of the cutter is about 0.1% to about 20% greater than the expanded dimension of the tissue stabilizer. In some embodiments, the expanded dimension of the cutter is about 0.1% to about 25% greater than the expanded dimension of the tissue stabilizer. In some embodiments, the expanded dimension of the cutter is about 1% to about 15% greater than the expanded dimension of the tissue stabilizer. In some embodiments, the expanded dimension of the cutter is about 1% to about 20% greater than the expanded dimension of the tissue stabilizer. In some embodiments, the expanded dimension of the cutter is about 1% to about 35% greater than the expanded dimension of the tissue stabilizer. In some embodiments, the device assembly further comprises a hydrophilic coating on the guidewire. In some embodiments, the device assembly further comprises a hydrophobic coating on the guidewire. In some embodiments, the device assembly further comprises a force sensor, a pressure sensor, or a force and pressure sensor incorporated into the distal tip of the guidewire. In some embodiments, the device assembly further comprises an oxygen saturation sensor incorporated into the guidewire. In some embodiments, the device assembly further comprises a cutting point or cutting edge incorporated into the distal tip of the guidewire. In some embodiments, the device assembly further comprises a curved or shaped end incorporated into the distal tip of the guidewire. In some embodiments, the tissue stabilizer comprising an inflatable balloon further comprises a flat surface that assumes a flush arrangement with the tissue surface when pulled against the septal wall in the left atrium. In some embodiments, the distal end of the balloon tissue stabilizer comprises a round shape; a square shape; a rectangular shape; a tapered shape; an oval shape; a triangular shape; a polygonal shape; a shape parallel to the atrial septum; or an atraumatic shape at the portion facing the non-atrial wall of the left atrium. In some embodiments, the tissue stabilizer comprising an inflatable balloon further comprises a "dot" shape. The balloon is axially configured to assume a "dog-bone" or "dumbbell" shape, where a portion of the inflated balloon is on each side of the atrial septum, thereby "sandwiching" the septum. In some embodiments, the axially configured inflatable balloon comprises two balloons that are filled separately and simultaneously. In some embodiments, the axially configured inflatable balloon comprises two balloons that are filled separately or simultaneously. In some embodiments, the axially configured inflatable balloon is one continuous balloon, with the same dimensions for each portion of the "dog-bone" or "dumbbell", different dimensions for each portion of the "dog-bone" or "dumbbell", or portions of the "dog-bone" or "dumbbell" that are individually translatable (with respect to each other). In some embodiments, the more proximal balloon of the "dog-bone" or "dumbbell" shaped configured balloon allows for an early warning if the distal tissue-holding balloon is at risk of being damaged by the cutter. In some embodiments, the expanded dimension of the tissue stabilizer is significantly smaller than the expanded dimension of the cutter to allow for tissue tenting of the atrial septum, such that the cutter forms an opening larger than the expanded dimension of the cutter. In some embodiments, the expanded dimension of the tissue stabilizer is less than about 5%; less than about 10%; less than about 15%; less than about 20%; less than about 25%; less than about 30%; less than about 35%; less than about 40%; less than about 45%; less than about 50%; or even less than about 75% of the expanded dimension of the cutter. In some embodiments, the tissue stabilizer further includes radiopaque markers or bands at strategic locations to guide or orient the location of the tissue stabilizer within the body, to orient the location of the tissue stabilizer relative to other system components, and to allow visualization and confirmation of its deployed state (i.e., expanded or equivalently folded). In some embodiments, the tissue stabilizer further provides embolic protection by ensuring that any excised tissue poked by the first catheter is captured and retained within the device assembly.In some embodiments, the balloon-containing tissue stabilizer features a protective skirt to protect the proximal edge of the inflated balloon. In some embodiments, the protective skirt includes: a single tine element; multiple tine elements; an expansion mesh; at least one bent wire; an expansion disk; an expansion fan; a spring coil; or at least one hinge arm. In some embodiments, the protective skirt expands and collapses relative to the state of the balloon. In some embodiments, the tissue stabilizer includes tines that expand outwardly after passing through the atrial septum, the tines having an expanded dimension less than a cutter dimension and configured to engage atrial septal tissue upon retraction, the tines further including barbs for engaging and stabilizing the atrial septal tissue before and after engagement with the cutter, where after engagement of the cutter, the tines fold in the same direction as they expand to capture tissue resected from the atrial septum during resheathing, and the cutter, resected tissue, and tines fold into the delivery catheter. In some embodiments, the tissue stabilizer includes tines that expand outwardly after passing through the atrial septal tissue, the tines having an expanded dimension less than the cutter dimension and configured to engage the atrial septum upon retraction, the tines further including barbs for engaging and stabilizing the atrial septal tissue before and after engagement with the cutter, where after engagement of the cutter, the tines are bent backwards from their original deployed state to capture the tissue resected from the atrial septum during resheathing, and the cutter, resected tissue, and tines are folded into the delivery catheter.In some embodiments, the tissue stabilizer comprises an expanding mesh; an expanding plate; an expanding disk; an expanding fan; or an expanding coil, where the tissue stabilizer is fabricated from a shape memory alloy that expands outward at an angle of approximately 90° after passing through the atrial septum, has an expanded dimension less than the expanded cutter dimension, and is configured to engage and stabilize the atrial septum when pulled back before or after engagement with the cutter, and after engagement with the cutter, the tissue stabilizer folds in the same direction as it expands to capture tissue resected from the atrial septum during resheathing, and the cutter, resected tissue, and tissue stabilizer fold into the delivery catheter. In some embodiments, the tissue stabilizer, including an expanding mesh, or an expanding plate, or an expanding disk, is axially configured to assume a "dogbone" or "dumbbell" shape, where an element or elements of the expanded structure are on each side of the atrial septum, thereby "sandwiching" the atrial septum. In some embodiments where more than one expanding mesh element is placed in the left atrium, the expanded dimension of the tissue stabilizer is about 5%; about 10%; about 15%; about 20%; about 25%; about 30% larger than the expanded dimension of the cutter to prevent the cutting teeth from inadvertently damaging structures other than the atrial septum. In some embodiments, the tissue stabilizer includes at least one strut; at least one hinge arm; or alternatively, an umbrella stretcher, where the tissue stabilizer expands outward at an angle of approximately 90° after passing through the atrial septum, has an expanded dimension less than the cutter dimension, and is configured to engage and stabilize the atrial septum upon retraction before and after engagement with the cutter, and after engagement of the cutter, the tissue stabilizer folds in the same direction as it expands to capture tissue resected from the atrial septum during resheathing, and the cutting element, resected tissue, and tissue stabilizer fold into the delivery catheter.In some embodiments, the tissue stabilizer includes at least one bent wire; or alternatively, a spring coil, where the tissue stabilizer is fabricated from a shape memory alloy and is configured to expand in an outward direction approximately perpendicular to the longitudinal centerline of the first inner coaxial catheter or the second inner coaxial catheter after passing through the atrial septum, has a radial dimension less than the cutter dimension, and is configured to engage and stabilize the atrial septum when pulled back before or after engagement with the cutter, and after engagement with the cutter, the tissue stabilizer folds in the same direction as it expands to capture tissue resected from the atrial septum during resheathing, and the cutter, resected tissue, and tissue stabilizer are fitted into the delivery catheter.

[0005] A device assembly for treating heart failure is provided herein, the device assembly including: a delivery catheter having a central delivery lumen; a first inner coaxial catheter having a first lumen that slidably engages within the central delivery lumen of the delivery catheter; an expandable tissue stabilizer attached to the first inner coaxial catheter at or near its distal end and disposed along an exterior length of the first inner coaxial catheter; a second inner coaxial catheter having a second lumen that slidably engages over the first inner coaxial catheter and within the central delivery lumen of the delivery catheter; and an expandable cutter attached to the second inner coaxial catheter and disposed along an exterior length of the second inner coaxial catheter and configured to slidably traverse or engage within the central delivery lumen of the delivery catheter; and a coaxial alignment mechanism having a third lumen that slidably engages an outer diameter of the first inner coaxial catheter and an inner diameter of the second inner coaxial catheter and within the central delivery lumen of the delivery catheter. In some embodiments, the first inner coaxial catheter having a first lumen further comprises a needle-like piercing tip configured to penetrate the atrial septum. In some embodiments, the device assembly further comprises a coaxial guidewire slidably engaged within the first lumen of the first inner coaxial catheter configured to provide an actuation track for the device assembly. In some embodiments, the cutting dimension of the expandable cutter is adjustable and the dimension of the expandable tissue stabilizer is adjustable. In some embodiments, the coaxial alignment mechanism is a third inner coaxial catheter disposed along the entire length of the first and second inner catheters. In some embodiments, the distal end of the coaxial alignment mechanism has an oversized dimension to aid in tissue stabilization during the cutting process of the atrial septum.

[0006] A device assembly for treating heart failure is provided herein, the device assembly comprising: a delivery catheter having a central delivery lumen; a first inner coaxial catheter having a first lumen slidably engaged within the central delivery lumen of the delivery catheter; and an expandable cutter having a proximal end and a distal end, the proximal end being attached to the distal end of the first inner coaxial catheter, coaxial with the central delivery lumen of the delivery catheter, and configured to foldably reside within the delivery catheter and slidably traverse or engage. In some embodiments, the device assembly further comprises a second inner coaxial catheter having a second lumen slidably engaged within the first lumen of the first inner coaxial catheter. In some embodiments, the second inner coaxial catheter further comprises a needle-like puncture tip configured to penetrate the atrial septum. In some embodiments, the device assembly further comprises a coaxial guidewire slidably engaged within the second lumen of the second inner coaxial catheter configured to provide an actuation track for the device assembly. In some embodiments, the cutting dimension of the expandable cutter is adjustable. In some embodiments, the cutter material comprises a shape memory alloy including nickel-titanium, copper-aluminum-nickel, zinc-gold-copper, or combinations thereof. In some embodiments, the cutter comprises: a wire mesh structure; a wire connecting sharp teeth; a collapsible crown saw structure; a collapsible open-ended cylindrical structure; a collapsible open-ended barrel structure; a collapsible open-ended cone structure; or combinations thereof. In some embodiments, the expandable cutter is generally configured to have an expanded cross-sectional shape including: a circle; a square; a rectangle; a triangle; an oval; or a polygon. In some embodiments, the expandable cutter is exposed and expands from a collapsed size to an expanded shape with an adjustable size and coaxial with the first inner coaxial catheter when the distal end of the delivery catheter is retracted proximally. In some embodiments, the adjustable size of the expandable cutter is controllable by the amount of proximal retraction of the delivery catheter.In some embodiments, the expandable cutter includes an expandable lattice, and a distal end of the expandable cutter lattice includes a plurality of sharp edges configured to act as tissue cutting blades. In some embodiments, the expandable cutter includes an expandable lattice including a shape memory alloy, and a distal end of the expandable cutter lattice includes a plurality of sharp edges configured to act as tissue cutting blades. In some embodiments, the plurality of sharp edges configured to act as tissue cutting blades include a tissue penetrating end and one or more side edges having sharp knife-like edges. In some embodiments, the expandable cutter is configured to cut through the atrial septum. In some embodiments, the expandable cutter is generally configured to have an expanded cross-sectional shape including: a circle; a square; a rectangle; a triangle; an oval; or a polygon. In some embodiments, the plurality of sharp edges resemble wavy or straight teeth, where the tips of the teeth are pointed, rounded, or a combination thereof, and the roots of the teeth are pointed, rounded, or a combination thereof. In some embodiments, the expandable cutter includes a continuous blade including a shape memory alloy, where the distal end of the continuous blade is configured to operate as a circumferential (continuous) tissue cutter, including a single smooth, sharp knife edge; or multiple sharp serrated edges or teeth along the continuous blade; a single bevel knife edge; a double bevel knife edge; or a combination thereof. In some embodiments, the single smooth, sharp knife edge or multiple sharp serrated edges along the continuous blade are configured to operate as a tissue cutter. In some embodiments, the expandable cutter is configured to cut through the atrial septum. In some embodiments, the expandable cutter is generally configured to have an expanded cross-sectional shape including: a circle; a square; a rectangle; a triangle; an oval; or a polygon. In some embodiments, the multiple sharp serrated edges along the continuous blade resemble wavy or straight teeth, where the tip of the serrated edge is pointed, rounded, or a combination thereof, and the base of the serrated edge is pointed, rounded, or a combination thereof.In some embodiments, the first inner coaxial catheter further comprises an expandable balloon configured to controllably expand the expandable cutter, where a dimension of the cutter is controlled by expansion of the expandable balloon disposed within a central portion of the cutter. In some embodiments, the first inner coaxial catheter further comprises an expandable strut configured to controllably engage an inner dimension of the expandable cutter, where a dimension of the cutter is controlled by expansion of the expandable strut disposed within a central portion of the cutter.

[0007] A device assembly for treating heart failure is provided herein, the device assembly including: a delivery catheter having a central delivery lumen; a first inner coaxial catheter having a first lumen that slidably engages within the central delivery lumen of the delivery catheter; an expandable cutter attached to the first inner coaxial catheter near a distal end and disposed along an exterior length of the first inner coaxial catheter; a second inner coaxial catheter having a second lumen that slidably engages over the first inner coaxial catheter and within the central delivery lumen of the delivery catheter; and an expandable tissue stabilizer attached to the second inner coaxial catheter and disposed along an exterior length of the second inner coaxial catheter and over the cutter on the first inner coaxial catheter, configured to slidably traverse or engage within the central delivery lumen of the delivery catheter. In some embodiments, the first inner coaxial catheter having a first lumen further includes a needle-like puncture tip configured to penetrate the atrial septum. In some embodiments, the device assembly further includes a coaxial guidewire that can be slidably engaged within the first lumen of the first inner coaxial catheter. In some embodiments, the cutting dimension of the expandable cutter is adjustable and the dimension of the expandable tissue stabilizer is adjustable. In some embodiments, the coaxial guidewire slidably engaged within the first lumen of the first inner coaxial catheter is configured to provide an operating track for the device assembly. In some embodiments, the coaxial guidewire is configured to extend from the distal end of the first lumen of the first inner coaxial catheter and pass through an initial puncture site in the interatrial septum between the right atrium and the left atrium of the mammalian heart approximately at the fossa ovalis to provide an operating track for the device assembly into the left atrium. In some embodiments, the delivery catheter extends distally such that the distal end of the first inner coaxial catheter and the distal end of the second coaxial catheter are configured to traverse along the guidewire trajectory and pass through an initial puncture site in the interatrial septum, and the cutter also extends beyond the interatrial septum into the left atrium.In some embodiments, the delivery device is configured such that the cutter is configured to radially coaxially expand into the left atrium to an intended dimension when the delivery catheter is retracted proximally back into the right atrium by the distal end of the second coaxial catheter, drawing the tissue stabilizer therewith, where the distal end of the delivery catheter is further retracted back inside the right atrium to radially expand the tissue stabilizer to a sufficiently large dimension, where the external expanded dimension of the cutter is less than the internal dimension of the expanded tissue stabilizer, where the radially expanded dimension of the tissue stabilizer provides a supportive tensioning effect on the right atrial side of the atrial septum around the initial puncture site. In some embodiments, the internal dimension of the tissue stabilizer is greater than the external dimension of the cutter. In some embodiments, the first internal coaxial catheter is then retracted distally such that the expandable cutter is slidably retracted coaxially into the left atrial side of the atrial septum and relative to the tissue stabilizer. In some embodiments, the first inner coaxial catheter is further retracted until the fully expanded cutter engages or traverses the left atrial side of the interatrial septum, causing the cutter to completely cut through the interatrial septum, thereby forming an interatrial pressure relief opening in the interatrial septum. In some embodiments, the interatrial pressure relief opening is large enough to allow blood flow from the left atrium to the right atrium through the pressure relief opening such that no more than 50% of the blood in the left atrium is shunted to the right atrium. In some embodiments, the interatrial pressure relief opening is large enough and shaped to slow the natural healing process of tissue to maintain patency of the interatrial pressure relief opening in the interatrial septum without implanting a stent or valve therein. In some embodiments, the interatrial pressure relief opening is large enough or shaped to slow the natural healing process of tissue to maintain patency of the interatrial pressure relief opening in the interatrial septum without implanting a stent or valve therein. In some embodiments, the resected tissue cut from the atrial septum is captured and held between the cutter and the tissue stabilizer.In some embodiments, the stabilizing element is partially folded onto the cutter by partially retracting the stabilizing element into the delivery catheter and, at about the same time, the first inner coaxial catheter is retracted and the cutter is pulled into the opening of the partially folded tissue stabilizer on the second inner coaxial catheter where the cutter with the captured tissue stabilizer is folded and retracted into the delivery catheter with the captured resected tissue. In some embodiments, the device assembly further comprises a coaxial alignment element. In some embodiments, the coaxial alignment element is configured to provide convergence between the cutter and the tissue stabilizer. In some embodiments, the tissue stabilizer is selected from the group consisting of: expanding tines; expanding mesh; at least one bent wire; expanding cup; expanding cone; expanding cylinder; spring coil; at least two struts; at least two hinge arms; or combinations thereof. In some embodiments, the tissue stabilizer material comprises a shape memory alloy including nickel-titanium, copper-aluminum-nickel, zinc-gold-copper, or combinations thereof. In some embodiments, the cutter material comprises a shape memory alloy including nickel-titanium, copper-aluminum-nickel, zinc-gold-copper, or combinations thereof. In some embodiments, the cutter shape comprises a collapsible crown saw structure; a collapsible open-ended cylindrical structure; a collapsible open-ended barrel structure; a collapsible open-ended box structure; a collapsible open-ended cone structure; or combinations thereof. In some embodiments, the tissue stabilizer shape comprises a collapsible crown saw structure; a collapsible open-ended cylindrical structure; a collapsible open-ended barrel structure; a collapsible open-ended box structure; a collapsible open-ended cone structure; or combinations thereof. In some embodiments, the expandable cutter is generally configured to have an expanded cross-sectional shape including a circle; a square; a rectangle; a triangle; an ellipse; or a polygon.In some embodiments, the expandable cutter includes an expandable lattice comprising a shape memory alloy, and a distal end of the expandable cutter lattice includes a plurality of sharp edges configured to act as tissue cutters. In some embodiments, the plurality of sharp edges configured to act as tissue cutters include a tissue-piercing end and one or more side edges having sharp knife-like edges. In some embodiments, the expandable cutter is configured to cut through the atrial septum. In some embodiments, the expandable cutter is generally configured to have an expanded cross-sectional shape including: a circle; a square; a rectangle; a triangle; an oval; or a polygon. In some embodiments, the plurality of sharp edges resemble wavy or straight teeth, where the tips of the teeth are pointed, rounded, or a combination thereof, and the bases of the teeth are pointed, rounded, or a combination thereof. In some embodiments, the expandable cutter includes a continuous blade comprising a shape memory alloy, and where the distal end of the continuous blade includes a single smooth, sharp knife edge; or a plurality of sharp serrated edges along the continuous blade configured to act as a continuous tissue cutter. In some embodiments, a single smooth sharp knife blade or multiple sharp serrated edges along a continuous blade are configured to act as a circumferential (continuous) tissue cutting edge. In some embodiments, the expandable cutter is configured to cut through the atrial septum. In some embodiments, the multiple sharp serrated edges along the continuous blade resemble wavy or straight teeth, where the tips of the serrated edges are pointed, rounded, or a combination thereof, and the bases of the serrated edges are pointed, rounded, or a combination thereof.

[0008] Provided herein is a device assembly for treating heart failure, the device assembly comprising: a delivery catheter having a central delivery lumen; a first inner coaxial catheter having a first lumen slidably engaged within the central delivery lumen of the delivery catheter; an expandable tissue stabilizer attached to the first inner coaxial catheter at or about a distal end and disposed along an exterior length of the first inner coaxial catheter; a third inner coaxial catheter having a third lumen slidably engaged over an outer diameter of the first inner coaxial catheter; and a third catheter. a slider element slidably engaged along an outer diameter of the inner coaxial catheter and further including two or more struts; a second inner coaxial catheter having a second lumen slidably engaged over the third coaxial catheter and within a central delivery lumen of the delivery catheter; and an expandable cutter attached to the second inner coaxial catheter and at a distal end of the second inner coaxial catheter and configured to slidably traverse or engage within the central delivery lumen of the delivery catheter over the third coaxial catheter, the umbrella slide element, and the two or more struts. In some embodiments, the first inner coaxial catheter having a first lumen further includes a piercing tip configured to pierce the atrial septum. In some embodiments, the device assembly further includes a coaxial guidewire that can be slidably engaged within a first lumen of the first inner coaxial catheter. In some embodiments, the cutting dimension of the expandable cutter is adjustable and the dimension of the expandable tissue stabilizer is adjustable. In some embodiments, the coaxial guidewire is configured to provide an actuation track for the device assembly. In some embodiments, the guidewire extension is pushed through the original puncture site in the atrial septum into the left atrium, and then the penetrating tip of the first inner coaxial catheter is pushed into the left atrium of the mammalian heart approximately at the fossa ovalis. In some embodiments, the distal end of the first inner coaxial catheter is configured to traverse along the guidewire trajectory and through the original puncture site in the atrial septum, such that the tissue stabilizer also extends beyond the atrial septum into the left atrium.In some embodiments, the tissue stabilizer is coaxially expanded within the left atrium such that the expanded size of the tissue stabilizer is large enough to prevent the tissue stabilizer from being inadvertently pulled back through the original puncture site and such that the tissue stabilizer provides a supportive tensioning effect on the atrial septum around the original puncture site. In some embodiments, the delivery catheter is at least partially retracted distally to expose the cutter as it expands, where the third catheter is translated distally such that the slider element slidably engages within the cutter to engage two or more struts and radially increase the size of the cutter so that it is larger than the size of the stabilizing element. In some embodiments, the coaxially expandable tissue stabilizer is generally configured to have an expanded cross-sectional shape that includes: a circle; a square; a rectangle; a triangle; an oval; or a polygon. In some embodiments, the expandable cutter includes an expandable lattice, and a distal end of the expandable cutter lattice includes a plurality of sharp edges configured to act as tissue cutting blades. In some embodiments, the expandable cutter includes a shape memory alloy. In some embodiments, the plurality of sharp edges configured to act as tissue cutters include a tissue-piercing end and one or more side edges having sharp knife-like edges. In some embodiments, the expandable cutter is configured to cut through the atrial septum. In some embodiments, the expandable cutter is configured to have a generally expanded cross-sectional shape including: a circle; a square; a rectangle; a triangle; an oval; or a polygon. In some embodiments, the plurality of sharp edges resemble wavy or straight teeth, where the tips of the teeth are pointed, rounded, or a combination thereof, and the bases are pointed, rounded, or a combination thereof. In some embodiments, the expandable cutter includes a continuous blade, where the distal end of the continuous blade includes a single smooth, sharp knife edge configured to act as a circumferential (continuous) tissue cutter; or a plurality of sharpened serrated edges along the continuous blade. In some embodiments, the expandable cutter includes a shape memory alloy.In some embodiments, a single smooth sharp knife blade or multiple sharp serrated edges along a continuous blade are configured to act as a tissue cutting blade. In some embodiments, the expandable cutter is configured to cut through the atrial septum. In some embodiments, the expandable cutter is configured to have an expanded cross-sectional shape that generally includes: circular; square; rectangular; triangular; oval; or polygonal. In some embodiments, the multiple sharp serrated edges along the continuous blade resemble wavy or straight teeth, where the tips of the serrated edges are pointed, rounded, or a combination thereof, and the bases of the serrated edges are pointed, rounded, or a combination thereof.

[0009] Provided herein is a device assembly for treating heart failure, the device assembly comprising: a delivery catheter having a central delivery lumen; a first inner coaxial catheter having a first lumen that slidably engages within the central delivery lumen of the delivery catheter; an expandable tissue stabilizer attached to the first inner coaxial catheter at or about a distal end and disposed along an exterior length of the first inner coaxial catheter; and an expandable tissue stabilizer extending across an outer diameter of the first inner coaxial catheter including a compression element for engaging and supporting an atrial septum opposing the tissue stabilizer. a second inner coaxial catheter having a second lumen slidably engaged along the outer diameter of the second catheter; a coaxial spring-loaded plunger element slidably engaged along the outer diameter of the second catheter; a second inner coaxial catheter within the central delivery lumen of the delivery catheter; and an expandable cutter attached to the second inner coaxial catheter and at a distal end of the second inner coaxial catheter and configured to slidably traverse or engage within the central delivery lumen of the delivery catheter over the first coaxial catheter while compressing the spring-loaded plunger element. In some embodiments, the first inner coaxial catheter having a first lumen further includes a piercing tip configured to pierce the atrial septum. In some embodiments, the device assembly further includes a coaxial guidewire that can be slidably engaged within the first lumen of the first inner coaxial catheter. In some embodiments, the cutting dimension of the expandable cutter is adjustable and the dimension of the expandable tissue stabilizer is adjustable. In some embodiments, the coaxial guidewire is configured to provide an actuation track for the device assembly. In some embodiments, the guidewire extension is pushed through the original puncture site into the left atrium, after which the penetrating tip of the first inner coaxial catheter penetrates the interatrial septum from the right atrium to the left atrium of the mammalian heart approximately at the fossa ovalis. In some embodiments, the distal end of the first inner coaxial catheter is configured to traverse along the guidewire trajectory and pass through the original puncture site in the interatrial septum, such that the tissue stabilizer also extends beyond the interatrial septum into the left atrium.In some embodiments, the tissue stabilizer is coaxially expanded within the left atrium such that the expanded size of the tissue stabilizer is large enough to prevent the tissue stabilizer from inadvertently being pulled back through the original puncture site and such that the tissue stabilizer provides a supportive tensioning effect against the wall of the atrial septum surrounding the original puncture site. In some embodiments, the device assembly further includes a third inner coaxial catheter having a third lumen slidably engaged with an outer diameter of the second inner coaxial catheter slidably engaged within the central delivery lumen of the delivery catheter, and in some embodiments, the device assembly further includes a third inner coaxial catheter having a third lumen slidably engaged with an outer diameter of the first inner coaxial catheter slidably engaged within the central lumen of the second inner coaxial catheter. In some embodiments, the delivery catheter is at least partially retracted distally to expose the cutter as it expands, where the slider element slidably engages within the cutter to engage two or more struts and radially increase the dimension of the cutter so that it is larger than the dimension of the stabilizing element, and the third catheter is translated distally. In some embodiments, the expandable tissue stabilizer is generally configured to have an expanded cross-sectional shape including: a circle; a square; a rectangle; a triangle; an ellipse; or a polygon. In some embodiments, the expandable cutter includes an expandable lattice, and a distal end of the expandable cutter lattice includes a plurality of sharp edges configured to act as tissue cutting blades. In some embodiments, the expandable cutter includes a shape memory alloy. In some embodiments, the plurality of sharp edges configured to act as tissue cutting blades include a tissue penetrating end and one or more side edges having sharp knife-like edges. In some embodiments, the expandable cutter is configured to cut through the atrial septum. In some embodiments, the expandable cutter is generally configured to have an expanded cross-sectional shape including: a circle; a square; a rectangle; a triangle; an ellipse; or a polygon.In some embodiments, the plurality of sharp edges resemble wavy or straight teeth, where the tips of the teeth are pointed, rounded, or a combination thereof, and the bases of the teeth are pointed, rounded, or a combination thereof. In some embodiments, the expandable cutter comprises an expandable continuous blade comprising a shape memory alloy, where the distal end of the continuous blade comprises a single smooth, sharp knife edge; or a plurality of sharp serrated edges along the continuous blade configured to act as a continuous tissue cutter. In some embodiments, the single smooth, sharp knife edge or a plurality of sharp serrated edges along the continuous blade are configured to act as a tissue cutter. In some embodiments, the expandable cutter is configured to cut through the atrial septum. In some embodiments, the expandable cutter is generally configured to have an expanded cross-sectional shape including the following: circle; square; rectangle; triangle; oval; or polygon. In some embodiments, the multiple sharp serrations along the continuous blade resemble wavy or straight teeth, where the tip of the serrations is pointed, rounded, or a combination thereof, and the base of the serrations is pointed, rounded, or a combination thereof.

[0010] A device assembly for treating heart failure is provided herein, comprising: a delivery catheter for vascular access of a mammal having a central delivery lumen; a first inner coaxial catheter having a first lumen that slidably engages within the central delivery lumen of the delivery catheter; a tissue stabilizer attached to the first inner coaxial catheter at or near the distal end and disposed along the exterior length of the first inner coaxial catheter; a second inner coaxial catheter having a second lumen that slidably engages over the first inner coaxial catheter and within the central delivery lumen of the delivery catheter; and an expandable cutter attached to the second inner coaxial catheter and disposed along the exterior length of the second inner coaxial catheter and configured to slidably traverse or engage within the central delivery lumen of the delivery catheter. In some embodiments, the first inner coaxial catheter having a first lumen further comprises a needle-like puncture tip configured to penetrate the atrial septum. In some embodiments, the device assembly further includes a coaxial guidewire that can be slidably engaged within the first lumen of the first inner coaxial catheter. In some embodiments, the cutting dimension of the expandable cutter is adjustable and the dimension of the expandable tissue stabilizer is adjustable. In some embodiments, the coaxial guidewire slidably engaged within the first lumen of the first inner coaxial catheter is configured to provide an actuation track for the device assembly. In some embodiments, the second inner coaxial catheter includes a predetermined curve to orient the internal catheters and components upon exiting the central delivery lumen of the delivery catheter in a direction perpendicular to the interatrial septum between the right and left atria of the mammalian heart. In some embodiments, the delivery catheter includes a material that is sufficiently stiff to straighten the shaft of the second catheter while it is within the delivery catheter, where the other catheter is freely translatable within.

[0011] Provided herein is a device assembly for treating heart failure, the device assembly including: a delivery catheter having a delivery lumen housing all internal components; a first inner coaxial catheter having a first lumen that slidably engages within a central delivery lumen of the delivery catheter; a tissue stabilizer attached to the first inner coaxial catheter at or near its distal end and disposed along the exterior length of the first inner coaxial catheter; a second inner coaxial catheter having a second lumen that slidably engages over the first inner coaxial catheter and within the central delivery lumen of the delivery catheter; and an expandable cutter attached to the second inner coaxial catheter and disposed along the exterior length of the second inner coaxial catheter and configured to slidably traverse or engage within the central delivery lumen of the delivery catheter. In some embodiments, the device assembly further includes a third inner coaxial catheter having a third lumen slidably engaged with an outer diameter of the second inner coaxial catheter slidably engaged within the central delivery lumen of the delivery catheter, and in some embodiments, the device assembly further includes a third inner coaxial catheter having a third lumen slidably engaged with an outer diameter of the first inner coaxial catheter slidably engaged within the central lumen of the second inner coaxial catheter. In some embodiments, the first inner coaxial catheter having a first lumen further includes a needle-like puncture tip configured to penetrate the atrial septum. In some embodiments, the device assembly further includes a coaxial guidewire that can be slidably engaged within the first lumen of the first inner coaxial catheter. In some embodiments, the cutting dimension of the expandable cutter is adjustable and the dimension of the expandable tissue stabilizer is adjustable. In some embodiments, the coaxial guidewire slidably engaged within the first lumen of the first inner coaxial catheter is configured to provide an actuation track for the device assembly.In some embodiments, the delivery catheter or the first, second or third inner coaxial catheter includes a predetermined bend that orients the internal catheters and components in a direction perpendicular to the atrial septum between the right and left atria of the mammalian heart upon exiting the central delivery lumen of the delivery catheter. In some embodiments, the delivery catheter is substantially rigid to straighten the third catheter while it is inside the delivery catheter, while the other catheters are still free to translate inside. In some embodiments, the cutter further includes an electrocautery element; a cryoablation element; an RF (radio frequency) element; a thermal ablation element; or a chemical or pharmacological delivery element; configured to retard tissue regeneration. In some embodiments, the electrocautery element includes a monopolar or bipolar element. In some embodiments, the device assembly further includes a radiopaque marker on the delivery catheter to aid in orientation and placement within the right atrium and to allow visualization in relation to other assembly components. In some embodiments, the device assembly further comprises a mechanism at or about the proximal end of the device assembly configured to provide alternative actuation and movement of the cutter to the user, including a handle; a knob; a hydraulic connection; a pneumatic connection; an electric motor connection; or an audio or vibratory connection, the alternative actuation and movement including rotational and reciprocating motions. In some embodiments, the device assembly further comprises an automated auscultation device for long-term non-invasive monitoring of flow or pressure through / across the created shunt. In some embodiments, the first inner coaxial catheter is a balloon catheter, a shape memory alloy mesh containing catheter, a shape memory alloy mesh catheter, or a guide catheter. In some embodiments, the second inner coaxial catheter is a blade catheter. In some embodiments, the tissue stabilizer is reinforced or armored against the expandable cutter in a compressed or expanded state. In some embodiments, the cutter comprises one or more foldable waveforms. In some embodiments, the cutter comprises one or more foldable sinusoidal waveforms.In some embodiments, the tissue stabilizer includes more than one expandable mesh disk. In some embodiments, the tissue stabilizer includes more than one expandable mesh disk, and at least one of the more than one expandable mesh disks expands when distal to the atrial septum and in the left atrium. In some embodiments, the tissue stabilizer includes more than one expandable mesh disk, and at least two of the more than one expandable mesh disks are of different thicknesses. In some embodiments, the guide catheter is configured to be inserted into the right atrium over an internal coaxial guidewire, the coaxial guidewire being pre-inserted into the right atrium. In some embodiments, the shape memory alloy mesh-containing catheter is configured to advance past the atrial septum into the left atrium. In some embodiments, the coaxial guidewire is configured to be removed after insertion of the shape memory alloy mesh-containing catheter into the left atrium. In some embodiments, the shape memory alloy mesh catheter is configured to be inserted into the left atrium via a shape memory alloy framework catheter. In some embodiments, the shape memory alloy mesh-containing catheter is configured to internally surround the shape memory alloy mesh catheter. In some embodiments, the shape memory alloy mesh catheter comprises one or more expandable shape memory alloy meshes configured to expand when external to the shape memory alloy mesh containing catheter. In some embodiments, the one or more expandable shape memory alloy meshes comprise at least two expandable shape memory alloy meshes that expand with the intervening atrial septum. In some embodiments, the expandable tissue stabilizer is self-expandable when unsheathed. In some embodiments, the expandable cutter is self-expandable when unsheathed. In some embodiments, the delivery catheter is wire reinforced or braided. In some embodiments, the delivery catheter comprises a reinforced distal tip. In some embodiments, the delivery catheter comprises a bend radius of about 0.5 inches to about 4 inches.In some embodiments, the guide catheter is configured to bend in a predetermined manner toward the atrial septum. In some embodiments, the expandable cutter is configured to create multiple perforations in the atrial septum after expansion. In some embodiments, the expandable cutter is configured to translate through the atrial septum, thereby making a complete cut in the atrial septum after expansion. In some embodiments, the cutter includes a proximal edge and a distal edge. In some embodiments, the proximal edge does not expand when the cutter expands. In some embodiments, the tissue stabilizer includes more than one expandable mesh disc, and at least one of the more than one expandable mesh discs expands when distal to the atrial septum and in the right atrium. In some embodiments, two of the more than one expandable mesh discs sandwich the atrial septum when expanded. In some embodiments, two of the more than one expandable mesh discs touch and sandwich the atrial septum when expanded. In some embodiments, the tissue stabilizer comprises more than one expandable mesh disc, where one of the more than one expandable mesh discs is configured to occlude the distal opening of the cutter or the distal opening of the delivery catheter when the tissue stabilizer is resheathed. In some embodiments, the shape memory alloy comprises Nitinol.

[0012] Provided herein is a method for transcatheter atrial septal ablation in a subject using a device assembly, the method including the steps of: enabling vascular access for the device assembly, the device assembly being in a sheathed state; puncturing the fossa ovalis of the atrial septum of the subject and advancing a guidewire therethrough to the left atrium; advancing the device assembly in a sheathed state over the guidewire to the right atrium; advancing a guide catheter over the guidewire to contact the atrial septum; and advancing a containment catheter over the guidewire to the left atrium. The method includes the steps of: inserting a tissue stabilizer into the left atrium; removing the guidewire from the subject; introducing a compressed tissue stabilizer at the proximal edge of the containment catheter and advancing it toward the distal edge of the containment catheter; expanding the tissue stabilizer at the left atrium; delivering a cutter to the right atrium, where the cutter is surrounded by a second compressed delivery catheter; expanding the cutter at the right atrium; translating the cutter forward to cut the atrial septum while the tissue stabilizer is exerting a reverse tension; and resheathing the cutter with the cut atrial septum into the delivery catheter. In some embodiments, the cut atrial septum includes at least a portion of the atrial septum. In some embodiments, the device assembly includes a delivery catheter, a guide catheter, a guidewire, a tissue stabilizer containment catheter, a tissue stabilizer, and a cutter. In some embodiments, the tissue stabilizer or the cutter is self-expanding. In some embodiments, the expansion of the tissue stabilizer is by self-expansion. In some embodiments, the expansion of the tissue stabilizer comprises unsheathing one or more disks in the left atrium. In some embodiments, the expansion of the cutter in the right atrium is by movement of the delivery catheter relative to the cutter. In some embodiments, the methods disclosed herein comprise resheathing the cutter, the guide catheter, the containment catheter, and the tissue stabilizer into the delivery catheter.In some embodiments, the methods disclosed herein include removing the resheathed device assembly from the subject. In some embodiments, advancing a guide catheter over the guidewire to the atrial septum includes advancing the guide catheter from the delivery catheter. In some embodiments, the methods disclosed herein include puncturing the fossa ovalis of the atrial septum of the subject using a prefabricated transseptal puncture kit to allow the guidewire to be left behind.

[0013] Provided herein is a method for transcatheter atrial septal ablation in a subject using a device assembly, the method comprising: advancing a guide catheter over a guidewire from a delivery catheter to the right atrium; advancing a tissue stabilizer-containing catheter from the guide catheter over the guidewire and across the atrial septum to the left atrium, where the tissue stabilizer is surrounded by the containing catheter in a compressed state; expanding the tissue stabilizer at the left atrium by moving the tissue stabilizer from the containing catheter over the guidewire and allowing the tissue stabilizer to self-expand; expanding a cutter at the right atrium; translating the cutter forward to cut the atrial septum while the tissue stabilizer exerts counter-tension against the atrial septum; and resheathing the tissue stabilizer along with the cut atrial septum into the cutter. In some embodiments, the cut atrial septum includes at least a portion of the atrial septum. In some embodiments, the methods disclosed herein include puncturing the fossa ovalis of the atrial septum of the subject and advancing a guidewire therethrough to the left atrium. In some embodiments, the methods disclosed herein include advancing a device assembly over the guidewire to the right atrium, where the device assembly is sheathed. In some embodiments, the methods disclosed herein include moving the tissue stabilizer to contact the atrial septum at a proximal edge of the tissue stabilizer, thereby sandwiching the atrial septum between the distal edge of the guide catheter and the proximal edge of the tissue stabilizer. In some embodiments, expanding the cutter is by advancement of the cutter against the right atrium or by retraction of the delivery catheter against the right atrium behind the self-expanding portion of the cutter. In some embodiments, the tissue stabilizer occludes the distal opening of the delivery catheter between the cutter and the resheathing of the tissue stabilizer. In some embodiments, the methods described herein include the step of resheathing the cutter into the delivery catheter, the cutter surrounding the tissue stabilizer and the severed atrial septum therein.In some embodiments, the tissue stabilizer blocks the distal opening of the delivery catheter during resheathing. In some embodiments, the tissue stabilizer blocks the distal opening of the cutter during resheathing. In some embodiments, the methods described herein include removing the resheathed device assembly from the subject. In some embodiments, the tissue stabilizer blocks the distal opening of the delivery catheter during removal of the resheathed device assembly. In some embodiments, the methods described herein include expanding the tissue stabilizer, including deploying more than one self-expanding disk, either simultaneously or at various times. In some embodiments, one of the disks is deployed in the left atrium. In some embodiments, one of the disks is deployed in the right atrium. In some embodiments, the methods described herein include expanding the tissue stabilizer in the left atrium by moving the tissue stabilizer from the containment catheter and allowing the tissue stabilizer to self-expand, including pushing at least a portion of the self-expanding portion of the tissue stabilizer past the containment catheter in the left atrium. In some embodiments, the methods described herein include removing the guidewire from the subject after advancing the tissue stabilizer sheathing catheter from the guide catheter at the atrial septum, hi some embodiments, the methods described herein include removing the guidewire from the subject before unsheathing the tissue stabilizer from the sheathing catheter and allowing the tissue stabilizer to self-expand in the left atrium.

[0014] Provided herein is a method for transcatheter atrial septal ablation in a subject using a device assembly, the method comprising: advancing a guide catheter over a guidewire from a delivery catheter to the right atrium, advancing a containing catheter of a tissue stabilizer from the guide catheter over the guidewire across the atrial septum to the left atrium, where the tissue stabilizer is surrounded by the containing catheter in a compressed state, expanding a first self-expanding disk of the tissue stabilizer in the left atrium and expanding a second self-expanding disk in the right atrium, thereby sandwiching the atrial septum between the first and second self-expanding disks, expanding a cutter in the right atrium, translating the cutter forward to cut the atrial septum while the tissue stabilizer is exerting reverse tension, and resheathing the tissue stabilizer along with the cut atrial septum into the cutter. In some embodiments, the cut atrial septum includes at least a portion of the atrial septum. In some embodiments, the methods described herein include moving the containment catheter into the right atrium, thereby contacting the first self-expanding disk with the atrial septum. In some embodiments, the methods described herein include expanding the first self-expanding disk of the tissue stabilizer by moving a self-expanding proximal edge of the cutter past a distal edge of the containment catheter. In some embodiments, the methods described herein include expanding a second self-expanding disk in the right atrium by moving a distal edge of the containment catheter from the left atrium to the right atrium. In some embodiments, the methods disclosed herein include contacting a distal portion of the guide catheter with a proximal edge of the second self-expanding disk after moving the containment catheter into the right atrium. In some embodiments, the cut atrial septum is sandwiched between the first and second self-expanding disks during the resheath. In some embodiments, the methods described herein include removing the guidewire from the subject after advancing the containment catheter of the tissue stabilizer from the guide catheter over the guidewire past the atrial septum to the left atrium.In some embodiments, the methods described herein include removing the guidewire from the subject before expanding the first self-expanding disk of the tissue stabilizer in the left atrium. In some embodiments, the methods described herein include puncturing the fossa ovalis of the atrial septum of the subject and advancing the guidewire therethrough to the left atrium. In some embodiments, the methods described herein include advancing a device assembly over the guidewire to the right atrium, where the device assembly is sheathed. In some embodiments, the methods described herein include expanding the cutter by advancement of the cutter against the right atrium or by retraction of the delivery catheter against the right atrium behind the self-expanding portion of the cutter. In some embodiments, the methods described herein include resheathing the cutter into the delivery catheter, where the cutter encloses the tissue stabilizer and the severed atrial septum therein. In some embodiments, the tissue stabilizer blocks the distal opening of the delivery catheter during resheathing. In some embodiments, the tissue stabilizer blocks the distal opening of the cutter during resheathing. In some embodiments, the severed atrial septum is sandwiched between the first and second self-expanding discs during resheathing. In some embodiments, the methods disclosed herein include removing the resheathed device assembly from the subject. In some embodiments, the severed atrial septum is sandwiched between the first and second self-expanding discs during removal of the resheathed device assembly from the subject. In some embodiments, deploying the tissue stabilizer includes deploying more than one self-expanding disc, either simultaneously or at different times. In some embodiments, at least one of the discs is deployed in the left atrium. In some embodiments, at least one of the discs is deployed in the right atrium.

[0015] Provided herein is a method for treating congestive heart failure in a subject using a device assembly, the method including the steps of: enabling vascular access for the device assembly, the device assembly being in a sheathed state; puncturing the fossa ovalis of the interatrial septum of the subject and advancing a guidewire therethrough to the left atrium; advancing the device assembly in a sheathed state over the guidewire to the right atrium; advancing a guide catheter over the guidewire to contact the interatrial septum; and advancing a containment catheter over the guidewire to the left atrium. The method includes the steps of: inserting a tissue stabilizer into the left atrium; removing the guidewire from the subject; introducing a compressed tissue stabilizer at the proximal edge of the containment catheter and advancing it toward the distal edge of the containment catheter; expanding the tissue stabilizer at the left atrium; delivering a cutter to the right atrium, where the cutter is surrounded by a second compressed delivery catheter; expanding the cutter at the right atrium; translating the cutter forward to cut the atrial septum while the tissue stabilizer is exerting a reverse tension; and resheathing the cutter with the cut atrial septum into the delivery catheter. In some embodiments, the cut atrial septum includes at least a portion of the atrial septum. In some embodiments, the device assembly includes a delivery catheter, a guide catheter, a guidewire, a tissue stabilizer containment catheter, a tissue stabilizer, and a cutter. In some embodiments, the tissue stabilizer or the cutter is self-expanding. In some embodiments, the expansion of the tissue stabilizer is by self-expansion. In some embodiments, expanding the tissue stabilizer includes unsheathing one or more disks in the left atrium. In some embodiments, the methods described herein include expanding the cutter in the right atrium by movement of the delivery catheter relative to the cutter. In some embodiments, the methods disclosed herein include resheathing the cutter, the guide catheter, the containment catheter, and the tissue stabilizer into the delivery catheter.In some embodiments, the methods disclosed herein include removing the resheathed device assembly from the subject. In some embodiments, advancing a guide catheter over the guidewire to the atrial septum includes advancing the guide catheter from the delivery catheter. In some embodiments, the methods disclosed herein include puncturing the fossa ovalis of the atrial septum of the subject using a prefabricated transseptal puncture kit to allow the guidewire to be left behind.

[0016] Provided herein is a method for treating congestive heart failure in a subject using a device assembly, the method comprising: advancing a guide catheter over a guidewire from a delivery catheter to the right atrium, advancing a tissue stabilizer storage catheter from the guide catheter over the guidewire and across the atrial septum to the left atrium, where the tissue stabilizer is in a compressed state and surrounded by the storage catheter, expanding the tissue stabilizer at the left atrium by moving the tissue stabilizer from the storage catheter over the guidewire and allowing the tissue stabilizer to self-expand, expanding a cutter at the right atrium, translating the cutter forward to cut the atrial septum while the tissue stabilizer exerts counter-tension against the atrial septum, and resheathing the tissue stabilizer along with the cut atrial septum into the cutter. In some embodiments, the cut atrial septum includes at least a portion of the atrial septum. In some embodiments, the methods disclosed herein include puncturing the fossa ovalis of the atrial septum of the subject and advancing a guidewire therethrough to the left atrium. In some embodiments, the methods disclosed herein include advancing a device assembly over the guidewire to the right atrium, where the device assembly is sheathed. In some embodiments, the methods disclosed herein include moving the tissue stabilizer to contact the atrial septum at a proximal edge of the tissue stabilizer, thereby sandwiching the atrial septum between the distal edge of the guide catheter and the proximal edge of the tissue stabilizer. In some embodiments, expanding the cutter is by advancement of the cutter against the right atrium or by retraction of the delivery catheter against the right atrium behind the self-expanding portion of the cutter. In some embodiments, the tissue stabilizer occludes the distal opening of the delivery catheter between the cutter and the resheathing of the tissue stabilizer. In some embodiments, the methods described herein include the step of resheathing the cutter into the delivery catheter, the cutter surrounding the tissue stabilizer and the severed atrial septum therein.In some embodiments, the tissue stabilizer blocks a distal opening of the delivery catheter during resheathing. In some embodiments, the tissue stabilizer blocks a distal opening of the cutter during resheathing. In some embodiments, the method described herein includes removing the resheathed device assembly from the subject. In some embodiments, the tissue stabilizer blocks a distal opening of the delivery catheter during removal of the resheathed device assembly. In some embodiments, expanding the tissue stabilizer includes deploying more than one self-expanding disk simultaneously or at various times. In some embodiments, one of the disks is deployed in the left atrium. In some embodiments, one of the disks is deployed in the right atrium. In some embodiments, the method described herein includes expanding the tissue stabilizer in the left atrium by moving the tissue stabilizer from the containment catheter and allowing the tissue stabilizer to self-expand, including pushing at least a portion of the self-expanding portion of the tissue stabilizer past the containment catheter in the left atrium. In some embodiments, the methods described herein include removing the guidewire from the subject after advancing the tissue stabilizer sheathing catheter from the guide catheter at the atrial septum, hi some embodiments, the methods described herein include removing the guidewire from the subject before unsheathing the tissue stabilizer from the sheathing catheter and allowing the tissue stabilizer to self-expand in the left atrium.

[0017] Provided herein is a method for treating congestive heart failure in a subject using a device assembly, the method comprising: advancing a guide catheter over a guidewire from a delivery catheter to the right atrium, advancing a containing catheter of a tissue stabilizer from the guide catheter over the guidewire to the left atrium, over the atrial septum, where the tissue stabilizer is in a compressed state and surrounded by the containing catheter, expanding a first self-expanding disk of the tissue stabilizer at the left atrium and expanding a second self-expanding disk at the right atrium, thereby sandwiching the atrial septum between the first and second self-expanding disks, expanding a cutter at the right atrium, translating the cutter forward to cut the atrial septum while the tissue stabilizer is exerting reverse tension, and resheathing the tissue stabilizer along with the cut atrial septum into the cutter. In some embodiments, the cut atrial septum includes at least a portion of the atrial septum. In some embodiments, the method described herein includes moving the containment catheter into the right atrium, thereby contacting the first self-expanding disk with the atrial septum. In some embodiments, expanding the first self-expanding disk of the tissue stabilizer is by movement of a self-expanding proximal edge of the cutter past a distal edge of the containment catheter. In some embodiments, expanding the second self-expanding disk in the right atrium is by movement of a distal edge of the containment catheter from the left atrium to the right atrium. In some embodiments, the method disclosed herein includes contacting a distal portion of the guide catheter with a proximal edge of the second self-expanding disk after moving the containment catheter into the right atrium. In some embodiments, the cut atrial septum is sandwiched between the first and second self-expanding disks during the resheath. In some embodiments, the method described herein includes removing the guidewire from the subject after advancing the containment catheter of the tissue stabilizer from the guide catheter over the guidewire and past the atrial septum to the left atrium.In some embodiments, the methods described herein include removing the guidewire from the subject before expanding the first self-expanding disk of the tissue stabilizer in the left atrium. In some embodiments, the methods described herein include puncturing the fossa ovalis of the atrial septum of the subject and advancing the guidewire therethrough to the left atrium. In some embodiments, the methods described herein include advancing the device assembly over the guidewire to the right atrium, where the device assembly is sheathed. In some embodiments, expanding the cutter is by advancement of the cutter against the right atrium or by retraction of the delivery catheter against the right atrium behind the self-expanding portion of the cutter. In some embodiments, the methods described herein include resheathing the cutter into the delivery catheter, where the cutter encloses the tissue stabilizer and the severed atrial septum therein. In some embodiments, the tissue stabilizer blocks the distal opening of the delivery catheter during resheathing. In some embodiments, the tissue stabilizer blocks the distal opening of the cutter during resheathing. In some embodiments, the severed atrial septum is sandwiched between the first and second self-expanding discs during resheathing. In some embodiments, the methods disclosed herein include removing the resheathed device assembly from the subject. In some embodiments, the severed atrial septum is sandwiched between the first and second self-expanding discs during removal of the resheathed device assembly from the subject. In some embodiments, deploying the tissue stabilizer includes deploying more than one self-expanding disc, either simultaneously or at different times. In some embodiments, at least one of the discs is deployed in the left atrium. In some embodiments, at least one of the discs is deployed in the right atrium. [Brief description of the drawings]

[0018] The novel features of the device assembly described herein are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present disclosure will be obtained by reference to the following detailed description that sets forth illustrative embodiments in which the principles of the device assembly described herein are utilized, and the accompanying drawings, in which: [Figure 1] FIG. 2 is a side view of an exemplary embodiment of a device assembly disclosed herein. [Diagram 2] FIG. 1 illustrates an exemplary embodiment of a transseptal puncture via the fossa ovalis. [Diagram 3] FIG. 1 illustrates an exemplary embodiment of a balloon catheter with a balloon inflated in the left atrium. [Figure 4A] FIG. 1 shows an exemplary embodiment of a cutter, a self-expanding shape-memory stent with a sharp blade at its distal end, delivered (and partially or completely unsheathed) into the right atrium. [Figure 4B] FIG. 1 shows an exemplary embodiment of a cutter, a self-expanding shape-memory stent with a sharp blade at its distal end, delivered (and partially or completely unsheathed) into the right atrium using a coaxial aligner. [Figure 5A] FIG. 13 is an exemplary embodiment of a cutter translated forward to penetrate and cut the atrial septum while a tissue stabilizer (balloon) applies opposing tension on the opposing surface. [Figure 5B] FIG. 13 is a diagram of an exemplary embodiment of a cutter with a coaxial aligner translated distally and forward to penetrate and cut the atrial septum while a tissue stabilizer (balloon) applies opposing tension on the opposing surface. [Figure 6A] FIG. 13 illustrates an exemplary embodiment of a tissue stabilizer (balloon catheter) being pulled proximally to the inner lumen and port of the cutter prior to resheathing the cutter with the resected tissue impinging on its respective catheter. [Figure 6B]FIG. 6B illustrates an exemplary embodiment of the tissue stabilizer (balloon catheter) of FIG. 6A being pulled back into the inner lumen and port of the cutter using a coaxial aligner prior to resheathing the cutter with the resected tissue impinging on its respective catheter. [Figure 7] FIG. 1 is a representative cross-sectional view of one embodiment of a device assembly while contained within a delivery catheter. [Figure 8] 4A-C are diagrams of alternative guidewire embodiments having various tip configurations, including versions having hydrophilic or hydrophobic coatings, one or more force sensors, one or more pressure sensors, oxygen saturation sensors, tissue cutting or piercing elements, or tissue stabilizing elements. [Figure 9] FIG. 1 is a representative diagram of one embodiment of a "dumbbell" or "dogbone" shaped tissue stabilizer. [Figure 10A] FIG. 13 is a representative diagram of an exemplary embodiment in which the diameter of the tissue stabilizer element is substantially smaller than the diameter of the cutter (in the expanded state) to permit tenting of tissue beyond the plane of the cutting edge prior to tissue destruction. [Figure 10B] FIG. 13 is a representative diagram of an exemplary embodiment of a substantially smaller diameter tissue stabilizer element with a larger diameter cutter (in an expanded state) forming an anastomosis by tissue tenting beyond the plane of the cutting edge at the point of tissue disruption. [Figure 11A] FIG. 13 is a representative diagram of an exemplary embodiment of a tissue stabilizer element sized slightly smaller than the diameter of the cutter to provide an opening that closely matches the diameter of the cutter, thereby minimizing tissue tenting prior to tissue destruction. [Figure 11B] FIG. 13 is a representative diagram of an exemplary embodiment of a stabilizer element sized slightly smaller than the diameter of the cutter to provide an opening that approximately matches the diameter of the cutter while forming an anastomosis, minimizing tissue tenting. [Figure 11C] FIG. 2 is a representative diagram of an exemplary embodiment of the alignment between the cutter and catheter (1) and catheter (2). [Figure 11D] FIG. 2 is another representative view of an exemplary embodiment of the alignment between the cutter and catheter (1) and catheter (2). [Figure 12A] 1A-1C are representative diagrams of an exemplary embodiment of a tissue stabilizer in the form of a balloon with a protective skirt to protect the proximal edge of the balloon while in a collapsed state. [Figure 12B] A representative diagram of an exemplary embodiment of a tissue stabilizer in the form of a balloon with a protective skirt to protect the proximal edge of the balloon during the expanded state, where the protective skirt expands and folds relative to the balloon state. [Figure 13A] FIG. 1 is a sequence of representative views of an exemplary embodiment of a tissue stabilizer in the form of tines that pass through the atrial septum but cannot allow retrograde passage through the initial puncture when fully deployed, where the tines are incorporated into the distal end of the catheter (1) and flatten in response to being pulled flush with the atrial septum. [Figure 13B] FIG. 1 is a sequence of representative views of an exemplary embodiment of a tissue stabilizer in the form of tines that pass through the atrial septum but cannot allow retrograde passage through the initial puncture when fully deployed, where the tines are incorporated into the distal end of the catheter (1) and flatten in response to being pulled flush with the atrial septum. [Figure 13C] FIG. 1 is a sequence of representative views of an exemplary embodiment of a tissue stabilizer in the form of tines that pass through the atrial septum but cannot allow retrograde passage through the initial puncture when fully deployed, where the tines are incorporated into the distal end of the catheter (1) and flatten in response to being pulled flush with the atrial septum. [Figure 14A]FIG. 13C is a representative view of an exemplary embodiment similar to that of FIGS. 13A-13C , showing the tines partially penetrating the atrial septum (with or without barbs at the end of each tine) to prevent the atrial septum from migrating off the tines, where after cutting, the expanded struts allow for resheathing of the catheter over the tines and excised tissue, followed by removal of the device assembly from the body. [Figure 14B] 13A-13C , showing the tines partially penetrating the atrial septum (with or without barbs at the end of each tine) to prevent the atrial septum from migrating off the tines, where the process of resheathing into the delivery catheter bends the tines back so that the tissue and tines fit into the delivery catheter. [Figure 14C] FIG. 13C is another representative view of an exemplary embodiment similar to that of FIGS. 13A-13C , showing the tines partially penetrating the atrial septum (with or without barbs at the end of each tine) to prevent the atrial septum from migrating off the tines, where the process of resheathing into the delivery catheter bends the tines back so that the tissue and tines fit into the delivery catheter when the delivery catheter is abutting the atrial septum. [Figure 15] AE is a series of representative views of an exemplary embodiment of a tissue stabilizer in the form of a loop supported by shape-setting tines. [Figure 16A] 1A-1C are representative diagrams of an exemplary embodiment of a tissue stabilizer having an "umbrella type" mechanism in an undeployed state. [Figure 16B] A representative view of FIG. 16A in a deployed state, where the tissue stabilizer is deployed by an "umbrella" mechanism and an increase in the diameter of the stabilizing element is induced by translating the catheter to the tip of the catheter holding the tissue stabilizer, which in turn causes the two stiff struts to rotate together by bending at the hinge points where they connect to the deployment catheter, to the holding catheter, and to each other. [Figure 17]FIG. 1 is a representative diagram of an exemplary embodiment of a coaxial alignment mechanism achieved by the inner diameter (ID) of catheter (2) being flush with the outer diameter (OD) of catheter (1) and the OD of catheter (2) being flush with the ID of catheter (3). [Figure 18] A representative diagram of an exemplary embodiment of a device assembly taking the form of the previous embodiment of FIG. 17, with the distinction that the ID of catheter (2) is adjusted in its distal aspect to form a space between catheter (1) and catheter (2) that functions as a tissue-retaining pocket. [Figure 19] FIG. 19 is a representative diagram of an exemplary embodiment of catheter (2) (1914) (coaxial with respect to catheter (1), (1902)) having an ID that is coplanar with the OD of catheter (1), (1902). [Figure 20] A representative diagram and views of one embodiment of a cutter are shown, where the cutter takes the form of an expandable lattice, which is equivalently referred to herein as an expandable stent made from a self-expanding material (i.e., a shape memory alloy; e.g., Nitinol) having a proximal end attached to the distal end of a catheter (2) (the catheter containing the expandable cutter) and a distal portion sharpened to create one or more cutting edges. [Figure 21] FIG. 1 is a representative diagram of an exemplary embodiment of a cutter in an expanded configuration, where the distal edge of the cutter has many (e.g., eight) serrated edges or equivalently teeth and forms an opening that is polygonal (e.g., octagonal) in cross section. [Figure 22] FIG. 22 is a representative view of the blade details shown in FIG. 21 with an enlarged view (circled) showing the two cutting edges on each tooth of the cutter in its expanded form and the tip detail at the distal end of the blade connected by a spring. [Figure 23] FIG. 1 is a representative diagram of an exemplary embodiment of the cutter in an expanded configuration, where the cutter blade is deployed exhibiting a coordinated cutting pattern requiring only one cutting edge on each tooth or serrated edge of the cutter. [Figure 24A]FIG. 13 is a representative view of an embodiment illustrating a series of wave-shaped cutter teeth culminating in a narrow point. [Figure 24B] FIG. 13 is a representative diagram of an embodiment illustrating a series of "U" shaped cutter teeth to create the appearance of a crown with pointed edges. [Figure 25A] FIG. 1 is a sequence of representative views of an exemplary embodiment of a reverse cutting operation, in which a cutter is attached to catheter (1) (living in the right atrium) and a tissue stabilization element is attached to catheter (2) and slidably engaged to the lumen of catheter (3). [Figure 25B] FIG. 1 is a sequence of representative views of an exemplary embodiment of a reverse cutting operation, in which a cutter is attached to catheter (1) (living in the right atrium) and a tissue stabilization element is attached to catheter (2) and slidably engaged to the lumen of catheter (3). [Figure 25C] FIG. 1 is a sequence of representative views of an exemplary embodiment of a reverse cutting operation, in which a cutter is attached to catheter (1) (living in the right atrium) and a tissue stabilization element is attached to catheter (2) and slidably engaged to the lumen of catheter (3). [Figure 25D] FIG. 1 is a sequence of representative views of an exemplary embodiment of a reverse cutting operation, in which a cutter is attached to catheter (1) (living in the right atrium) and a tissue stabilization element is attached to catheter (2) and slidably engaged to the lumen of catheter (3). [Figure 26A] FIG. 13 is a representative view of an embodiment of a cutter in a partially extended or partially deployed state using an "umbrella" mechanism. [Figure 26B] FIG. 26B is a representative view of FIG. 26A in a fully deployed or equivalently expanded state. [Figure 27A] FIG. 2 is a representative illustration of an embodiment of a cutter in a partially extended or partially deployed state, where the catheter (2) is connected to a coaxial alignment mechanism by a spring mechanism housed in its distal tip. [Figure 27B]FIG. 27B is a representative view of the deployed spring-plunger mechanism of FIG. 27A, where the spring urges the excised tissue distally from the cutter. [Figure 28A] FIG. 1 is a representative diagram of an embodiment of an assembly in which an inner catheter (2) (the catheter containing the expandable cutter) has a predetermined but flexible bend in one of the inner catheters inside the delivery catheter, but the delivery catheter is strong enough to include a non-distorting bend throughout the entire delivery catheter. [Figure 28B] FIG. 28B is a representative diagram of an embodiment of the assembly of FIG. 28A, where an additional inner catheter has a predetermined but flexible bend and is external to the inner catheter but still internal to the delivery catheter, but the delivery catheter is strong enough to include a distortion-free bend throughout the delivery catheter. [Figure 29] FIG. 11 is a general embodiment illustrating any of the above embodiments combined as a system with an automated auscultation device for chronic non-invasive monitoring of flow or pressure through or at an inter-atrial shunt. [Diagram 30] 1 is an illustrative side view of an embodiment of a device assembly. [Diagram 31] It illustrates a cross-sectional view of the heart with blood flowing from left to right through a pressure relieving shunt between the left and right atria of the heart. [Diagram 32] FIG. 1 is a graphical representation of an initial puncture of the atrial septum with a representative atrial decompression system with a guidewire and catheter including a tissue stabilization balloon passing from the right atrium to the left atrium, delivered percutaneously to the heart via an initial groin puncture. [Diagram 33] FIG. 33 is a representative diagram of the embodiment of the atrial decompression system of FIGS. 31 and 32 illustrating the sequential deployment of a self-expanding stent blade from a second coaxial catheter in the right atrium after deployment of a tissue stabilization balloon in the left atrium. [Diagram 34]FIG. 34 is a representative diagram of the embodiment of the atrial decompression system of FIGS. 31, 32, and 33, illustrating the sequential formation of a shunt through the atrial septum that is slightly larger than the diameter of the tissue stabilization balloon, utilizing self-expanding stent blades. [Diagram 35] FIG. 35 is a representative diagram of the embodiment of the atrial decompression system of FIGS. 31-34 illustrating the entire atrial decompression system being sequentially retracted with the self-expanding stent blades retracted into the coaxial catheter and delivery catheter, and tissue excised from the atrial septum being captured by the tissue stabilization balloon. [Diagram 36] 1 is an exemplary embodiment of a device assembly illustrating multiple shape memory alloy disks advanced over one or more catheters. [Figure 37] 1 is an exemplary embodiment of a device assembly as disclosed herein comprising a guide catheter having a predetermined bend. [Figure 38] A-D show an exemplary sequential embodiment of a device assembly described herein that eliminates the need for an additional mesh-containing catheter to deploy tissue stabilization elements when the guide catheter has a smaller OD at the distal end to ensure it passes through the atrial septum while extending over the guidewire. [Figure 39] 13 shows an exemplary embodiment of a cutter as described herein that first creates the periphery of the perforation and then completes a full circumferential cut by translation anteriorly through the atrial septum. [Diagram 40] 1 illustrates an exemplary embodiment of a cutter catheter disclosed herein, which optionally has a smaller internal lumen at its distal end for secure coaxial alignment with a balloon catheter or a shape memory alloy mesh-containing catheter. [Diagram 41] AE shows an exemplary embodiment of sequential procedural steps for applying a device assembly as disclosed herein. [Diagram 42]AF shows an exemplary embodiment of the sequential steps of using a device assembly as disclosed herein to cause deployment of a dog-bone shaped expandable tissue stabilizer sandwiching the atrial septum. [Diagram 43] A-D show an exemplary embodiment of a sequential process using a device assembly as disclosed herein in which a catheter including an expandable tissue stabilizer can be extended over the guidewire and deployed in the left atrium, eliminating the need to remove the guidewire. [Diagram 44] AE shows an exemplary embodiment of a sequential process using a device assembly as disclosed herein in which a catheter including an expandable tissue stabilizer can be extended over a guidewire and deployed in the left atrium and then the right atrium to pinch the atrial septum, thus eliminating the need to remove the guidewire. [Diagram 45] 1 shows an exemplary embodiment of a balloon catheter or nitinol mesh-containing catheter as disclosed herein, which features a larger outer diameter at its distal end to ensure coaxial alignment with a guide catheter or blade catheter. [Figure 46] 1 shows an exemplary embodiment of a procedural step using a device assembly as disclosed herein, which is a transseptal puncture through the fossa ovalis of the interatrial septum, leaving a guidewire in place. [Figure 47] 1 shows an exemplary embodiment of a procedural step using a device assembly as disclosed herein, in which a guide catheter is introduced from a delivery catheter over a guidewire and into contact with the atrial septum. [Figure 48] 1 shows an exemplary embodiment of a procedural step using a device assembly as disclosed herein, in which a shape memory alloy mesh delivery catheter is introduced from a guide catheter over a guidewire through the atrial septum at approximately 90 degrees. [Figure 49]1 illustrates an exemplary embodiment of a procedural step using a device assembly as disclosed herein, in which a shape memory alloy mesh tissue stabilization element is introduced into the right atrium via a shape memory alloy mesh delivery catheter, where it is deployed by self-expansion. [Figure 50] AC shows an exemplary embodiment of a procedural step using a device assembly as disclosed herein, in which a cutter (a self-expanding shape memory alloy stent or lattice with a sharp blade at its distal end) is delivered (sheathed) into the right atrium and the cutter is unsheathed in the right atrium by pullback of the delivery catheter. [Figure 51] 1 shows an exemplary embodiment of a procedural step using a device assembly as disclosed herein, in which the cutter translates forward to penetrate and cut the atrial septum while the tissue stabilizer applies reverse tension. [Figure 52A] 1 shows an exemplary embodiment of a procedural step using a device assembly as disclosed herein, in which a blade catheter, a guide catheter, a shape memory alloy mesh delivery catheter, cut tissue, and a shape memory alloy mesh tissue stabilizer are all pulled from the atrial septum. [Figure 52B] 1 shows an exemplary embodiment of a procedural step using a device assembly as disclosed herein, where the blade catheter, guide catheter, shape memory alloy mesh delivery catheter, excised tissue, and shape memory alloy mesh tissue stabilizer are all loaded into the delivery catheter just prior to removal of the entire system from the body. [Diagram 53] AB shows an exemplary embodiment of a device assembly as disclosed herein, where the distal tip of the guide catheter has a smaller diameter, more flexible section that is used to pass through the atrial septum and introduce the shape memory alloy mesh tissue stabilizer into the left atrium. [Figure 54]1 shows an exemplary embodiment of a device assembly as disclosed herein, in which the shape memory alloy mesh catheter features one or more shape memory alloy mesh disks abutting and distal to the atrial septum to 1) ensure that the resected (partially resected) tissue does not become dislodged from the atrial septum and the device, and 2) to serve as a fail-safe to allow the blades to continue translating through the atrial septum in the unlikely event that one of the shape memory alloy plugs is inadvertently pulled through the atrial septum before a full circumferential cut is completed. [Figure 55] AB shows an exemplary embodiment of one or more shape memory alloy discs and their sizes relative to the cutter of a device assembly as disclosed herein. [Figure 56A] 13A-13C show an exemplary sequential embodiment of the deployment of a shape memory alloy mesh of a device assembly, where the delivered shape memory alloy mesh tissue stabilizer takes the form of multiple overlapping petals. [Figure 56B] 13A-13C show an exemplary sequential embodiment of the deployment of a shape memory alloy mesh of a device assembly, where the delivered shape memory alloy mesh tissue stabilizer takes the form of multiple overlapping petals. [Figure 56C] 13A-13C show an exemplary sequential embodiment of the deployment of a shape memory alloy mesh of a device assembly, where the delivered shape memory alloy mesh tissue stabilizer takes the form of multiple overlapping petals. [Figure 56D] 13A-13C show an exemplary sequential embodiment of the deployment of a shape memory alloy mesh of a device assembly, where the delivered shape memory alloy mesh tissue stabilizer takes the form of multiple overlapping petals. [Figure 56E] 13A-13C show an exemplary sequential embodiment of the deployment of a shape memory alloy mesh of a device assembly, where the delivered shape memory alloy mesh tissue stabilizer takes the form of multiple overlapping petals. [Figure 57]1 shows an exemplary embodiment of an expandable tissue stabilizer of a device assembly as disclosed herein, where the distal end of the frusto-conical (trapezoidal shaped) tissue stabilizer is oversized relative to the expanded diameter of the blade to capture the penetrating tip of the cutter after the cut is completed. [Figure 58A] 13 illustrates another exemplary sequential embodiment of an expandable tissue stabilizer of a device assembly as disclosed herein, in which the delivered shape memory alloy mesh tissue stabilizer is folded into a flower-shaped pattern. [Figure 58B] 13 illustrates another exemplary sequential embodiment of an expandable tissue stabilizer of a device assembly as disclosed herein, in which the delivered shape memory alloy mesh tissue stabilizer is folded into a flower-shaped pattern. [Figure 58C] 13 illustrates another exemplary sequential embodiment of an expandable tissue stabilizer of a device assembly as disclosed herein, in which the delivered shape memory alloy mesh tissue stabilizer is folded into a flower-shaped pattern. [Fig. 58D] 13 illustrates another exemplary sequential embodiment of an expandable tissue stabilizer of a device assembly as disclosed herein, in which the delivered shape memory alloy mesh tissue stabilizer is folded into a flower-shaped pattern. [Figure 59A] 1 illustrates an exemplary sequential embodiment of an expandable tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer containing catheter is pulled back to unsheath one half of a self-expanding ovoid clip in the left atrium and the other half in the right atrium, thereby sandwiching the atrial septum therebetween. [Figure 59B] 1 illustrates an exemplary sequential embodiment of an expandable tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer containing catheter is pulled back to unsheath one half of a self-expanding ovoid clip in the left atrium and the other half in the right atrium, thereby sandwiching the atrial septum therebetween. [Figure 59C] 1 illustrates an exemplary sequential embodiment of an expandable tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer containing catheter is pulled back to unsheath one half of a self-expanding ovoid clip in the left atrium and the other half in the right atrium, thereby sandwiching the atrial septum therebetween. [Fig. 59D] 1 illustrates an exemplary sequential embodiment of an expandable tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer containing catheter is pulled back to unsheath one half of a self-expanding ovoid clip in the left atrium and the other half in the right atrium, thereby sandwiching the atrial septum therebetween. [Figure 59E] 1 illustrates an exemplary sequential embodiment of an expandable tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer containing catheter is pulled back to unsheath one half of a self-expanding ovoid clip in the left atrium and the other half in the right atrium, thereby sandwiching the atrial septum therebetween. [Figure 60A] 1 shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where a guide catheter has a predetermined bend and includes a self-expanding tissue stabilizer that is deployed in both the left and right atria by proximally retracting the catheter housing the tissue stabilizer as well as the guide catheter. [Figure 60B] 1 shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where a guide catheter has a predetermined bend and includes a self-expanding tissue stabilizer that is deployed in both the left and right atria by proximally retracting the catheter housing the tissue stabilizer as well as the guide catheter. [Figure 60C]1 shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where a guide catheter has a predetermined bend and includes a self-expanding tissue stabilizer that is deployed in both the left and right atria by proximally retracting the catheter housing the tissue stabilizer as well as the guide catheter. [Figure 60D] 1 shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where a guide catheter has a predetermined bend and includes a self-expanding tissue stabilizer that is deployed in both the left and right atria by pulling back the catheter that houses the tissue stabilizer as well as the guide catheter. [Figure 61A] 1 shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where a proximal portion of the self-expanding mesh is connected to a first ring that allows it to translate toward the distal end of the catheter containing the tissue stabilizer once the catheter containing the tissue stabilizer is pulled back to unsheath the mesh. [Figure 61B] 1 shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where a proximal portion of the self-expanding mesh is connected to a first ring that allows it to translate toward the distal end of the catheter containing the tissue stabilizer once the catheter containing the tissue stabilizer is pulled back to unsheath the mesh. [Figure 62] 1 shows an exemplary embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where the self-expanding mesh disc has a concave surface that only allows the outer edge of the mesh to touch the atrial septum to help prevent the mesh disc from being pulled through the atrial septum. [Figure 63A]1 shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where a self-wound wire is wrapped around and placed within a catheter (1), its proximal end is connected to a catheter that rotates and moves distally to either unwind the wire or expand the tissue stabilizer through a deep hole in the distal end of the catheter (1). [Figure 63B] 1 shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where a self-wound wire is wrapped around and placed within a catheter (1), its proximal end is connected to a catheter that rotates and moves distally to either unwind the wire or expand the tissue stabilizer through a deep hole in the distal end of the catheter (1). [Figure 63C] 1 shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where a self-wound wire is wrapped around and placed within a catheter (1), its proximal end is connected to a catheter that rotates and moves distally to either unwind the wire or expand the tissue stabilizer through a deep hole in the distal end of the catheter (1). [Fig. 63D] 1 shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where a self-wound wire is wrapped around and placed within a catheter (1), its proximal end is connected to a catheter that rotates and moves distally to either unwind the wire or expand the tissue stabilizer through a deep hole in the distal end of the catheter (1). [Figure 64] FIG. 13 shows an exemplary side view embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer includes a self-expanding mesh disk surrounding a small balloon that, once inflated, prevents the tissue stabilizer from being pulled through the atrial septum toward the right atrium. [Figure 65]FIG. 65 illustrates an exemplary end view embodiment of a tissue stabilizer of a device assembly as shown in FIG. 64 and as disclosed herein, where the tissue stabilizer includes a self-expanding mesh disk surrounding a small balloon that, once inflated, prevents the tissue stabilizer from being pulled through the atrial septum toward the right atrium. [Figure 66] 1 illustrates an exemplary embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer is a self-expanding coil. [Figure 67] 1 illustrates an exemplary embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer includes one or more self-expanding discs and one or more self-expanding hemispherical mesh plugs. [Figure 68] 1 shows an exemplary embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer includes two self-expanding hemispherical plugs on each side of the atrial septum, with the flat sides of the hemispheres facing the atrial septum. [Figure 69A] 1 illustrates an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer comprises a self-expanding hollow mesh filled with self-wound wires. [Figure 69B] 1 illustrates an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer comprises a self-expanding hollow mesh filled with self-wound wires. [Figure 70A] 1A-1C show exemplary side and front view embodiments of a possible tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer is a self-expanding oblate sphere. [Figure 70B] 1A-1C show exemplary side and front view embodiments of a possible tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer is a self-expanding oblate sphere. [Figure 71] 1 shows an exemplary embodiment of a possible self-expanding blade of a device assembly as disclosed herein, where the proximal edge of the self-expanding blade has a series of helical cutouts to aid in secure attachment to the catheter. [Figure 72A] 1 shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer is a shape memory alloy mesh that is expanded by translating the proximal and distal edges toward each other, forming a disk that sandwiches the atrial septum during that translation. [Fig. 72B] 1 shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer is a shape memory alloy mesh that is expanded by translating the proximal and distal edges toward each other, forming a disk that sandwiches the atrial septum during that translation. [Fig. 72C] 1 shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer is a shape memory alloy mesh that is expanded by translating the proximal and distal edges toward each other, forming a disk that sandwiches the atrial septum during that translation. [Figure 73A] 1 shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer takes the form of a series of intertwined petals when exposed distally from the catheter in the left atrium such that it appears flat in cross-section, thus acting as a stiff plate when deployed. [Figure 73B] 1 shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer takes the form of a series of intertwined petals when exposed distally from the catheter in the left atrium such that it appears flat in cross-section, thus acting as a stiff plate when deployed. [Figure 73C]1 shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer takes the form of a series of intertwined petals when exposed distally from the catheter in the left atrium such that it appears flat in cross-section, thus acting as a stiff plate when deployed. [Fig. 74A] 1 shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer consists of a series of radially self-expanding struts connected circumferentially by a series of shape memory bridges. In addition, there is an internal catheter (4) to the tissue stabilizer, which allows for the proximal folding of the struts and connected bridges after the atrial septum has been cut and the resected tissue folded inside the folded struts and bridges. [Fig. 74B] 1 shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer consists of a series of radially self-expanding struts connected circumferentially by a series of shape memory bridges. In addition, there is an internal catheter (4) to the tissue stabilizer, which allows for the proximal folding of the struts and connected bridges after the atrial septum has been cut and the resected tissue folded inside the folded struts and bridges. [Fig. 74C] 1 shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer consists of a series of radially self-expanding struts connected circumferentially by a series of shape memory bridges. In addition, there is an internal catheter (4) to the tissue stabilizer, which allows for the proximal folding of the struts and connected bridges after the atrial septum has been cut and the resected tissue folded inside the folded struts and bridges. [Fig. 74D]1 shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer consists of a series of radially self-expanding struts connected circumferentially by a series of shape memory bridges. [Figure 75] AE shows an exemplary sequential embodiment of a possible tissue stabilizer of a device assembly as disclosed herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] CHF is characterized by a weakening of the myocardium, either due to a weakened pumping function, known as heart failure with reduced ejection fraction (HFrEF), or a stiffening of the muscle with a reduced ability to fill with blood before ejection, known as heart failure with preserved ejection fraction (HFpEF). If the heart cannot eject or fill with blood, symptoms of shortness of breath, fatigue, and significant functional limitations result. The prevalence of HFrEF and HFpEF is generally comparable, but the rate of HFpEF is rising faster than HFrEF. With poor blood flow from the heart to vital organs, the renin-angiotensin-aldosterone system (RAAS) is activated, signaling the body to retain fluid, thereby increasing pressure in the heart chambers. Specifically, when left atrial pressure (LAP) increases, fluid backs up into the pulmonary circulation, resulting in pulmonary edema and severe shortness of breath. While normal adult LAP ranges from 10-15 mmHg, the LAP in patients with heart failure is frequently in the 30-40 mmHg range, which in some embodiments rises sharply during periods of increased heart demand.

[0020] Existing pharmacological treatments for heart failure attempt to remove excess fluid from the body via renal excretion (diuretics), neurohormonal blockade, or peripheral vasodilation to reduce the stress load on the failing heart. Although these pharmacological therapies provide some symptomatic relief and have shown modest mortality benefits in treating HFrEF, importantly, they have not been shown to improve survival for those with HFpEF.

[0021] Device-based treatments for heart failure are limited. Mechanical circulatory support, in which an electric pump is surgically implanted and takes over the function for the failing heart, is highly invasive and reserved for the progression of the final stages of the disease. Percutaneous mechanical pumps are used in the short-term setting, but are approved for short-term use only. Similarly, intra-aortic balloon pumps, which reduce cardiac afterload and improve coronary perfusion, are used only in the short-term inpatient setting. Finally, cardiac resynchronization therapy, in which an implanted pacemaker improves coordinated contractions of the failing ventricles, has shown excellent results for improving mortality in patients with heart failure and associated electrical conduction abnormalities.

[0022] Experimental treatments seek to reduce elevated left atrial pressure by implanting metallic stents in the interatrial septum that create a shunt between the high pressure left atrium and the low pressure right atrium. Because the right atrium and venous reservoir are highly compliant, in some embodiments, shunting blood from left to right effectively reduces left atrial pressure without a significant increase in right atrial pressure, thereby relieving symptoms and improving cardiac mechanics. Early human data from these interatrial shunts shows promise for improved functional status and hemodynamic parameters.

[0023] The optimal size of these interatrial shunts is unknown, but has been estimated using simulation data and early animal studies. Importantly, the size of the interatrial opening must be large enough to allow offloading of the left atrium without too much blood flowing to the right side, which would result in undue stress on the right atrium and ventricle. It is widely recognized among clinicians that individuals presenting with congenital atrial septal defects will endorse obstruction if the size of the defect results in a shunt fraction greater than 50%. Thus, sizing of the interatrial shunts such that no more than 50% of the left atrial blood is shunted is important to reduce long-term adverse effects.

[0024] Implantable interatrial shunts have a number of drawbacks. Because foreign material remains within the heart chamber and in contact with blood, blood clotting and thrombosis are a danger, possibly requiring pharmacological anticoagulation for extended periods or until endothelialization of the device surface occurs. Implantation also poses the risk of device breakage, dislodgement, or embolism. Implanted stents also, in some embodiments, may limit the freedom of the catheter to move within the left atrium, making subsequent transseptal procedures difficult. Finally, if occlusion is ever desired, bulky stents, in some embodiments, add to the difficulty of sealing the interatrial shunt.

[0025] Balloon atrial septostomy is a procedure with associated medical devices that attempts to create an interatrial opening to allow mixing of blood between the left and right sides of the heart. This device is used in the pediatric population to treat congenital heart lesions prior to definitive surgical correction. A deflated balloon, with or without attached blades, is introduced via the venous system across the interatrial septum into the left atrium. The balloon is then inflated and pulled proximally, thereby tearing the septum and opening the interatrial opening. This device creates an interatrial opening that is not replicable between patients. As the septum is torn, the resulting tissue flap remains in place and eventually fuses back together. The openings created by these device assemblies close uniformly over a period of several months. The temporary nature of these interatrial openings makes them suitable for short-term treatment of congenital birth defects, but they are not useful in the adult heart failure population where a more permanent treatment is desired.

[0026] Therefore, a device capable of creating a sized atrial opening for intra-atrial pressure relief in a manner that ensures "long-term" patency without the need for implantation would be advantageous. The use of such a device would achieve equivalent physiologic function to an implantable stent without the negative sequelae of left-behind devices. It is desirable to create a precisely sized opening that remains patent for the duration of the desired therapeutic effect. It would also be advantageous to create such an opening via a minimally invasive procedure, as this treatment is likely to be most beneficial in a patient population with a high comorbidity burden. Therefore, the purpose of this device is to enable the creation of a precisely sized opening via a small (<18Fr, <6.0mm, <0.236 inch) percutaneous puncture.

[0027] The present disclosure relates to a device assembly and method for treating heart failure by lowering elevated blood pressure in the left atrium of a mammalian heart. Disclosed herein, in some embodiments, is a transcatheter atrial septal ablation device assembly configured to create a sized atrial opening between the right and left atrium for relief of elevated left atrial pressure to allow shunting of 50% or less of left atrial blood to the right atrium of the heart. In some embodiments, the device assembly includes a delivery catheter, a tissue stabilizer attached to a first catheter having a central lumen and a piercing tip that allows passage of a guidewire, and a cutter attached to a second catheter having a central lumen that allows passage of the first catheter. In some embodiments, the device assembly disclosed herein includes a (third) catheter having a central lumen that allows passage of the aforementioned components to and from the right atrium or that resides coaxially within the central lumen of the aforementioned components, a tissue retention mechanism, and an optional coaxial alignment mechanism.

[0028] In some embodiments, a prefabricated lumen with a penetrating tip and guidewire is configured for use with the transcatheter atrial septal ablation device assembly herein, thus simplifying the design of the transcatheter atrial septal ablation device assembly by removing the penetrating tip and guidewire from the main device assembly, thereby simplifying complexity and reducing cost. One example of such a prefabricated lumen with a penetrating tip and guidewire is the Swartz™ Braided Transseptal Guiding Introducers LAMP™ Series, model number 407366, which is 180 cm long and 0.035 inches in diameter. In some embodiments, a prefabricated vascular access sheath is used to deploy the device assembly into the femoral vein. Disclosed herein in some embodiments is a device assembly for treating heart failure, the device assembly comprising: a delivery catheter having a central delivery lumen; a first inner coaxial catheter having a first lumen slidably engaged within the central delivery lumen of the delivery catheter; an expandable tissue stabilizer attached to the first inner coaxial catheter at or near its distal end and positioned along the outer length of the first inner coaxial catheter; a second inner coaxial catheter having a second lumen slidably engaged on the first inner coaxial catheter and within the central delivery lumen of the delivery catheter; and an expandable cutter attached to the second inner coaxial catheter, positioned along the outer length of the second inner coaxial catheter, and configured to slidably traverse or engage within the central delivery lumen of the delivery catheter. In some embodiments, the first inner coaxial catheter having a first lumen further comprises a needle-like puncture tip configured to penetrate the atrial septum. In some embodiments, the device assembly comprises a coaxial guidewire slidably engaged within the first lumen of the first inner coaxial catheter. In some embodiments, the cutting size of the expandable cutter is adjustable and the size of the expandable tissue stabilizer is adjustable.In some embodiments, the coaxial guidewire extends from the distal end of the first lumen of the first inner coaxial catheter and is configured to pass through an initial puncture site in the atrial septum between the right and left atria of the mammalian heart approximately at the fossa ovalis to provide a working track for the device assembly in the left atrium. In some embodiments, the distal end of the first inner coaxial catheter is configured to traverse along the guidewire trajectory and pass through the initial puncture site in the atrial septum such that the tissue stabilizer also extends past the atrial septum into the left atrium. In some embodiments, the tissue stabilizer is coaxially expanded within the left atrium such that its dimensions are large enough to prevent the tissue stabilizer from being pulled back into the original puncture site, and the tissue stabilizer provides a supportive tensioning effect on the wall of the atrial septum surrounding the original puncture site. In some embodiments, a second inner coaxial catheter extends from the delivery catheter such that an expandable cutter is slidably advanced and coaxially expanded to a cutting dimension greater than the expanded dimension of the tissue stabilizer. In some embodiments, the second inner coaxial catheter extends further until the fully expanded cutter engages or traverses the right atrial side of the interatrial septum at or around the fossa ovalis such that the cutter fully penetrates and cuts the septum, thereby resulting in an interatrial pressure relief opening in the interatrial septum, where the interatrial pressure relief opening is sized sufficiently to allow blood to flow through the interatrial pressure relief opening from the left atrium to the right atrium such that no more than 50% of the left atrial blood is shunted to the right atrium, and where the interatrial pressure relief opening is sufficiently large and / or shaped to slow the natural healing process of tissue to maintain patency of the interatrial pressure relief opening in the interatrial septum without implanting a stent or valve therein. In some embodiments, the tissue section excised from the atrial septum is captured and maintained between the cutter and the tissue stabilizer.In some embodiments, the stabilizing element is partially folded and the first inner coaxial catheter is retracted until the captured resected tissue and at least a portion of the partially folded stabilizing element are pulled into the opening of an expanded cutter positioned on the second inner coaxial catheter. In some embodiments, the cutter is retracted and folded into the lumen of the delivery catheter, where the stabilizing element simultaneously fully folds inside the cutter to capture the resected tissue therein. In some embodiments, the device assembly further includes a coaxial alignment element. In some embodiments, the coaxial alignment element is configured to provide centralization between the cutter and the tissue stabilizer.

[0029] Overview of Device Assembly Elements

[0030] As shown in FIG. 1, in some embodiments, the device assembly (100) includes a guidewire (101); a tissue stabilizer, or tissue stabilizing element (104), as used herein in its equivalent, optionally attached to an inner catheter (102) (alternatively and synonymously referred to herein as a first catheter, inner catheter (1), inner catheter (1), first coaxial catheter, first inner coaxial catheter, or catheter (1)), where catheter (1) has a central lumen that allows passage of the guidewire; a second catheter (106) (alternatively and synonymously referred to herein as an inner catheter (2), coaxial catheter (2), second coaxial catheter, second inner coaxial catheter, or catheter (1)). a cutter (108) optionally attached to a delivery catheter (102) (alternatively referred to herein as a delivery catheter (3), delivery catheter, or containment sheath, and in some embodiments referred to as a steerable delivery catheter (3)), where the delivery catheter (3) has a central lumen that permits passage of the aforementioned components to and from the right atrium; a tissue retention mechanism, optionally including a tissue stabilizer (104), a cutter (108), a catheter (102) therebetween, or any combination thereof; and a coaxial alignment mechanism (112). As previously mentioned, the guidewire (101) is optionally configured as a separate, off-the-shelf component that is individually packaged and utilized, or configured to operate seamlessly with the other elements of the device assembly. Thus, FIG. 1 is a side view of an exemplary embodiment of a device assembly disclosed herein.Illustrated in FIG. 1 is a device assembly (100) that includes a guidewire (101), optionally provided as an off-the-shelf accessory or integrated device component; a tissue stabilizer (104) (alternatively and interchangeably referred to herein as a tissue stabilization element); a cutter configured to cut atrial septal tissue and that is foldable in some embodiments and fabricated from a shape memory alloy such as NiTi (wherein the cutter is alternatively and interchangeably referred to herein as a foldable cutter or an expandable cutter); a first catheter (102) (alternatively and interchangeably referred to herein as an inner catheter, inner catheter (1), inner catheter 1, first coaxial catheter, first inner coaxial catheter, or catheter (1)) configured to deliver the tissue stabilizer; a second catheter (103) configured to deliver the cutter; 06) (wherein the second catheter is alternatively and interchangeably referred to herein as inner catheter (2), coaxial catheter (2), second coaxial catheter (2), second inner coaxial catheter, or catheter (2)), a delivery catheter (110) configured to introduce and carry catheter (1) and catheter (2), or both catheter (1) and catheter (2) (wherein the delivery catheter is alternatively and interchangeably referred to herein as delivery catheter (3), delivery catheter, or containing sheath, and in some embodiments referred to as steerable delivery catheter (3)), and a coaxial aligner (112) located on catheter (2) proximal to the cutter (wherein proximal refers to closer to the delivery catheter handle, in contrast to distal refers to closer to the guidewire opening of the delivery assembly where the guidewire exits the inner lumen of catheter (1).

[0031] In some embodiments, as previously described, the device assembly can be configured with or without an integral penetrating tip and guidewire, but whether provided as an integral component or as an attachment to the device assembly, once the guidewire is positioned across (through) the atrial septum it is utilized by the device assembly to provide a working track for the device assembly components, and is removed with the device assembly once the procedure is complete.

[0032] In some embodiments, the coaxial aligner, or a coaxial mechanism via the aligner or other parts of the device assembly, provides centralization between the cutter, tissue stabilizer, tissue retention element, or combinations thereof. The coaxial aligner reduces the risk of inadvertent interaction between the cutter and tissue stabilizer (e.g., as catheter (1) is translated proximally into catheters (2) or (3)). The coaxial aligner also serves as a means to ensure that the cutter (connected to catheter (2)) is advanced centrally over and through the septum of catheter (1).

[0033] Optionally, the entire device assembly can also be configured for delivery via a prefabricated steerable catheter configured with an appropriate internal diameter to support the (external) delivery catheter of the device assembly. As further illustrated in the cross-sectional view of FIG. 7, in an exemplary embodiment, a transcatheter atrial septal resection device assembly (700) includes a catheter (1) (702) with a tissue stabilizer (706) attached thereon, a catheter (2) including a cutter (708), a delivery catheter (3) (710) sheathing the catheter (1), the tissue stabilizer in a collapsed state, and the cutter in a collapsed state, and the device assembly (700) is further configured with or without an integrated guidewire (701) having a tissue-penetrating tip. In some embodiments, an additional catheter is required to accommodate the tissue stabilizer that preserves the tissue stabilizer in a collapsed state prior to deployment, the catheter having a central lumen that allows passage of the catheter (1) and is slidably engaged within the central lumen of the catheter (2) (706). In this particular embodiment, the elements within the delivery catheter (3) (710) are coaxially positioned with two or more elements overlapping along the length or elongation of the delivery catheter. In some embodiments, when the device assembly is deployed, the elements within the delivery catheter physically contact each other for stability and support of the entire device assembly. In some embodiments, when the device assembly is properly deployed, the elements within the delivery catheter nevertheless remain relative to the other one or more elements. Thus, FIG. 7 is a representative cross-sectional view of one or more embodiments of the device assembly.

[0034] 28A-28B, in certain embodiments, the mechanism of orthogonal orientation of the atrial septum of the assembly disclosed herein is shown relative to the anatomy of the heart. In the embodiment shown in FIG. 28A, the inner catheter (2) (2806) has a predetermined but flexible bend, while the delivery catheter (3) (2810) is strong enough to contain the bend without distortion of the entire delivery catheter prior to deployment. Upon distal deployment of the inner catheter, the device assembly typically bends in an orthogonal direction toward the fossa ovalis. In some embodiments, the fossa ovalis is a depression in the right atrium of the heart at the level of the atrial septum (2820), the wall between the right and left atria. The fossa ovalis is a remnant of a thin fibrous sheet that covers the foramen ovale during fetal development. The foramen ovale is a small hole located in the septum (wall) between the two upper (atrial) chambers of the heart in some embodiments. The foramen ovale is used in fetal circulation to speed the movement of blood through the heart. Also shown in this particular embodiment are a guidewire (2801), catheter (1) (2802), and tissue stabilizer (2804).

[0035] 28B is an exemplary implementation of the embodiment of the assembly of FIG. 28A, where the additional inner catheter has a predetermined but flexible bend and is external to the inner catheter, but still internal to the delivery catheter, but the delivery catheter is strong enough to include a non-distorting bend throughout the delivery catheter. Upon distal deployment of the additional inner catheter, the device assembly bends orthogonally, typically toward the fossa ovalis, optionally perpendicular to the fossa ovalis. In some embodiments, the delivery catheter optionally includes a steer ring cable (not shown).

[0036] Referring to FIG. 29, in an exemplary embodiment, an assembly as disclosed herein and its individual components are combined as a system (2900) with an automated auscultation device assembly for long-term non-invasive monitoring of flow or pressure through or across the created shunt.

[0037] Referring now to FIG. 30, there is illustrated a schematic of the "working end" (distal end) of device assembly (3000), which in some embodiments may include an optional prefabricated or integral guidewire (3001) (with piercing tip), catheter (1) (3002), tissue stabilizer (3004) (by way of non-limiting example, a balloon or tine), catheter (2) (3006) (for a cutter), cutter (3007), and catheter (3008). 008) (a self-expanding shape-memory stent having blades at its distal end), and a delivery catheter (3) (3010) (optionally steerable or configurable within a steerable off-the-shelf delivery catheter), and referring to FIG. 31 , a cross-sectional view of a human heart (3100) including a right atrium (3020), a left atrium (3018), and an anastomotic shunt (3014) illustrates blood flow in a left to right direction through a pressure relief shunt between the left and right atria of the heart.

[0038] 31-35, there is seen a sequential illustration of the creation of an atrial shunt in a human heart utilizing a device assembly in a particular embodiment, the creation comprising the following steps: - percutaneously delivering the assembly (3000) (optionally undeployed or partially deployed) over a guidewire (3001), through the femoral vein, and into the inferior vena cava supplying the right atrium (3020) of the heart (3100), wherein the delivery catheter (3) (3010), the guidewire (3001), or the steerable catheter (1) (3002) are deployed in some embodiments during this step; - creating an initial puncture in the atrial septum (3016), where a guidewire (3001) includes a puncture tip and a coaxial catheter (1) (3002) includes a tissue stabilizer (3004) (e.g., a balloon) passing from the right atrium (3020) to the left atrium (3018) and expanding the balloon to stabilize the tissue against the atrial septum; - deploying a self-expanding cutter (3008) from the coaxial catheter (2) (3006) into the right atrium after placement of the tissue stabilizer in the left atrium; - creating an anastomotic shunt (3014) through the atrial septum (3016) utilizing a self-expanding cutter (3008) slightly larger in diameter than the tissue stabilizer (3004) and capturing the resected tissue (3012); and - withdrawing the entire atrial decompression system (3000), wherein the self-expanding cutter is withdrawn into the lumen of the delivery catheter following or simultaneously with withdrawal of the resected tissue from the atrial septum, where it is captured within the folded blades of the self-expanding cutter and held in place by the tissue stabilizer into the delivery catheter, and then the entire device assembly (including the guidewire) is withdrawn from the heart and body via the initial groin puncture.

[0039] Figures 8A-C illustrate alternative guidewire embodiments having various tip configurations including hydrophilic or hydrophobic coatings, one or more pressure sensors, oxygen saturation sensors, penetrating tips, or tissue-cutting tips, or further including tissue stabilizing elements (alternatively referred to herein as tissue stabilizers). Figure 9 is a representative illustration of one embodiment of a "dumbbell" or "dogbone" shaped tissue stabilizer, showing one embodiment guidewire with a lumen passing through the tissue stabilizer.

[0040] In some embodiments, as shown in FIGS. 8A-C and 9, a guidewire (801)(901) is placed across the atrial septum (800)(900) at or around a weak point (805) in the fossa ovalis of the septum using standard transseptal puncture techniques. The guidewire (801)(901) provides a working track along which the device assembly is advanced. Components of the device assembly, such as various catheters (902) and tissue stabilizers (904), in some embodiments, are translated along the guidewire relative to each other and the septum. The system optionally includes a transseptal puncture kit with a guidewire, which is often available as a standard off-the-shelf item. By way of example, one such kit is the Swartz™ Braided Transseptal Guiding Introducers LAMP™ Series, model number 407366, which is 180 cm long and 0.035 inches in diameter.

[0041] In some embodiments, the guidewire has a hydrophilic coating that allows the catheter (1) to translate with low friction along its length. In some embodiments, the tip of the guidewire features a curved or shaped puncture tip to prevent inadvertent trauma at its distal end. The curved tip is held straight within the delivery catheter and introduced into the atrial septum via a dilator and introducer to facilitate penetration of the atrial septum. The curved tip is held straight within the delivery catheter and introduced into the atrial septum via a dilator or introducer to facilitate penetration of the atrial septum. Once through the atrial septum, the tip of the puncture tip is configured to bend against itself to avoid inadvertent puncture of unintended tissue. A common material for this type of bent tip is Nitinol, a nickel-titanium alloy. In some embodiments, other types of materials and shape memory substances that function similarly as Nitinol are used for the guidewire. In some embodiments, the guidewire includes a sheath or cover that covers the puncturing tip after puncturing, such that the puncturing tip does not need to include a self-curving tip. In some embodiments, the tip of the guidewire is fitted to include a detector or sensor that facilitates guidewire delivery, puncturing, and post-puncturing bending. In some embodiments, the tip of the guidewire is fitted to include a detector or sensor that facilitates guidewire delivery, puncturing, or post-puncturing bending. In some embodiments, a therapeutic agent is optionally carried on the tip or along the guidewire to enable drug delivery before or after the anastomosis between the atria.

[0042] In some embodiments, a force or pressure sensor (805) is incorporated into the guidewire (801) to assist in identifying the thinnest and most compliant portion of the atrial septum as the guidewire tip is guided to explore different regions of the tissue.

[0043] In some embodiments, an oxygen saturation method is incorporated into the guidewire to provide confirmation of delivery (oxygenated blood) to the left atrium. To provide confirmation, a saturation analysis is optionally obtained first in the right atrium (before transseptal puncture) and again in the left atrium after puncture, with the difference in saturation confirming successful puncture. In some embodiments, the analysis is performed only in the left atrium, with accurate puncture confirmed by comparison with a preselected saturation value. In some embodiments, the guidewire features a cutting or puncturing element at its distal end (the tip of the device assembly away from the operator). In some embodiments, the cutting or puncturing element at the distal end features a curved or shaped tip to also prevent inadvertent trauma at the distal end. In some embodiments, the end of the guidewire introducer sheath includes a straightener to straighten the cutting or puncturing element immediately prior to delivery or withdrawal through the atrial septum.

[0044] In some embodiments, the guidewire features a hydrophobic coating.

[0045] In some embodiments, the guidewire is coaxially and slidably engaged within the first lumen of the first inner coaxial catheter and is configured to provide an actuation track for the device assembly.

[0046] In some embodiments, the guidewire is a solid wire or a hollow elongated tube, optionally including a lumen therein. In some embodiments, the guidewire includes a weave pattern that includes a lumen therein, which makes it easier to puncture or self-bend back than a solid elongated wire. In some embodiments, the guidewire includes a weave pattern that includes a lumen therein, which makes it easier to puncture and self-bend back than a solid elongated wire. In some embodiments, materials are used for the guidewire, including metals, alloys, composites, or biomaterials.

[0047] In some embodiments, the guidewire is equivalent to the guide catheter herein. In some embodiments, the guide catheter houses the guidewire therein.

[0048] In some embodiments, a guidewire is placed across the atrial septum using standard transseptal puncture techniques. In some embodiments, the guidewire provides an operating track along which the device assembly is advanced. Components of the device assemblies disclosed herein are translated along the guidewire relative to each other and the septum in some embodiments.

[0049] In some embodiments, the guidewire includes a hydrophobic coating thereon. In some embodiments, the guidewire includes a force or pressure sensor incorporated into the distal tip. In some embodiments, the guidewire includes an oxygen saturation sensor. In some embodiments, the guidewire includes a cutting point or cutting edge incorporated into the distal tip. In some embodiments, the guidewire includes a curved or shaped end at the distal tip.

[0050] In some embodiments, the device assemblies disclosed herein include a tissue stabilizer, tissue stabilization element, or the use thereof. In some embodiments, the tissue stabilizer is equivalent to the tensioning element herein.

[0051] In some embodiments, the tissue stabilizer comprises an inflatable balloon; an expansion tine; an expansion mesh; at least one bent wire; an expansion plate; an expansion disk; an expansion fan; a spring coil; at least one strut; at least one hinge arm; an umbrella stretcher; or a combination thereof. In some embodiments, the tissue stabilizer is configured to expand outwardly to an angle of 75°-105° after fully passing through the septum, with a dimension less than the expanded dimension of the cutter, and to be pulled proximally to engage the septum and stabilize the septum before and after engagement with the cutter; after engagement of the cutter, the tissue stabilizer folds in the same direction it was opened, capturing the cutter, the resected tissue, and the resected tissue from the septum as the cutter is resheathed such that the tissue stabilizer folds into the delivery catheter.

[0052] 9-12B, in some embodiments, the device assemblies disclosed herein include a tissue stabilizer (904)(1004)(1104)(1204) (connected to the catheter (1)) that provides tension against the actuation of the cutter (1008)(1108) so as to minimize unintended tissue deformation, rotation, or displacement due to unbalanced forces. In some embodiments, this also serves to capture tissue resected from the atrial septum (900)(1000)(1100) and prevent tissue from slipping out after resection.

[0053] In some embodiments, the tissue stabilizer elements take the form of inflatable, deformable, expandable, or biased elements, such as balloons with or without coverage, expandable meshes, coil springs, which are integrated into a catheter that is advanced over the guidewire and across the septum, and then expanded and pulled back to contact the left atrial side of the atrial septum. In some embodiments, the tissue stabilizer includes one or more individual elements at different positions along the elongation direction. In some embodiments, the expanding element features a flat proximal surface toward the septum that assumes a horizontal configuration with respect to the tissue plane when pulled against the septum. In some embodiments, the expanding element features a proximal surface of other suitable shape that facilitates stabilization of the device assembly to the septum. In some embodiments, the proximal characteristics of the balloon reduce the risk of inadvertently pulling the balloon through the septum ensuring tissue retention. The proximal surface of the expandable element, optionally flat, is slightly undersized (in the expanded state) relative to the cutter to ensure the creation of a specifically defined opening. The specifically defined openings, in some embodiments, are tailored to a specific size based on the cutter dimensions. In various embodiments, the distal end of the balloon is rounded, rectangularized, tapered, or atraumatic at the portion facing the free wall of the left atrium. In some embodiments, the tissue stabilizer, when pulled against the septum, prevents relative motion of one or more elements of the device assembly toward the right and left atria. In some embodiments, the tissue stabilizer, when pulled against the septum, prevents relative motion of one or more elements of the device assembly toward the right or left atrium. In some embodiments, the first coaxial catheter features a tissue stabilization element (or equivalently a tissue stabilizer) at or immediately adjacent to the distal end. In some embodiments, the first coaxial catheter features a tissue stabilization element positioned a short distance (i.e., 3.0-5.0 mm) proximal to the distal end. In some embodiments, the first coaxial catheter features multiple tissue stabilization elements at multiple locations along the extension length.

[0054] In some embodiments, the tissue stabilizer comprises a bent wire or spring coil. In some embodiments, the tissue stabilizer is fabricated from a shape memory alloy that is configured to expand after it has completely passed through the septum in an outward direction generally perpendicular to the longitudinal centerline of the catheter and its radial dimension is less than the expanded dimension of the cutter, and is configured to engage the septum and retract to stabilize the septum before or after engagement with the cutter; after engagement with the cutter, the tissue stabilizer folds in the same direction it was opened, capturing the tissue resected from the septum when the cutter is resheathed such that the resected tissue and tissue stabilizer fit within the delivery catheter.

[0055] In some embodiments, as shown in FIG. 9, balloons (904) (tissue stabilizers) are inflated from catheter (1) (902) on each side of the septum (900) to aid in tissue stabilization. The balloons are axially shaped similar to a "dog bone" to pinch the tissue between each end during inflation, forming a "dog bone" shape. Various embodiments include more than one balloon, which may be inflated together or separately, may be one continuous balloon, may be the same diameter, may be different diameters, or may be inflatable separately from each other. Additionally, the more proximal balloons allow for an early warning when the most distal one and the balloon holding the tissue is at risk of being damaged by the cutter.

[0056] In some embodiments (not shown), the tissue stabilizer includes expandable, elastic shape memory alloy tines that function in a manner similar to the inflatable balloon tissue stabilizers described above. In some embodiments, the tissue stabilizer includes a mechanically expandable, elastic lattice or similar mesh that functions similar to the expandable elements. In some embodiments, the tissue stabilizer includes a biased element that functions similar to the expandable elements. In some embodiments, the tissue stabilizer includes an expandable, elastic element that is expanded by chemical, biological, physical factors, or a combination thereof.

[0057] In some embodiments, as shown in FIGS. 10A-10B, the diameter of the tissue stabilizer element (1004) when deployed from the catheter (1) (1002) along the guidewire (1001) is substantially smaller than the cutter (1008) (in the expanded state), thereby allowing tissue tenting beyond the cutting plane prior to tissue destruction by pulling the tissue adjacent to or toward the cutter, the cage formed thereby, or the right atrium, and artificially creating a larger atrial septal surface (1000) exposed to the cutter. This configuration allows the creation of an opening larger than the diameter of the cutter. In some embodiments, a coaxial aligner (1012) secured to the catheter (2) (1006) or the cutter (1008) ensures coaxial penetration and alignment of the components. FIG. 10A is a representative example of an exemplary embodiment of a tissue stabilizer element diameter substantially smaller than the cutter (in the expanded state) to allow tissue tenting beyond the cutting plane prior to tissue destruction. FIG. 10B is a representative example of an exemplary embodiment of a tissue stabilizer element having a substantially smaller diameter, which is larger than the cutter (in an expanded state) that creates an anastomosis with tissue tenting beyond the cutting surface at the point of tissue disruption.

[0058] In some embodiments, as shown in Figures 11A and 11B, the tissue stabilizer (1104) element is sized "only slightly" smaller than the diameter of the cutter (1108) to provide an opening that more closely matches the diameter of the cutter, minimizing tissue tenting prior to tissue destruction. In this embodiment, it is important to ensure coaxial alignment between the cutter and the tissue stabilizer with the guide (1112), as shown in Figures 11A-11D, to prevent inadvertent contact between the two elements during cutting, as well as between the cutter and catheters (1) and (2). Catheter (1) (1102), catheter (2) (1106), cutter (1108), and coaxial aligner (1112) are also shown in Figures 11C and 11D. In some embodiments (not shown), the tissue stabilizer element features imaging markers, such as radiopaque bands, at strategic locations to orient the device assembly in the body, relative to other system components, and allow visibility and confirmation of the deployed state (expanded or collapsed). FIG. 11A is a representative example of an exemplary embodiment of a tissue stabilizer element sized slightly smaller than the diameter of the cutter to provide an opening that more closely matches the diameter of the cutter and minimize tissue tenting prior to tissue destruction. FIG. 11B is a representative example of an exemplary embodiment of a tissue stabilizer element sized slightly smaller than the diameter of the cutter to provide an opening that more closely matches the diameter of the cutter and minimize tissue tenting during anastomosis. FIG. 11C is a representative example of an exemplary embodiment of alignment between the cutter and catheter (1) and catheter (2). FIG. 11D is another representative example of an exemplary embodiment of alignment between the cutter and catheter (1) and catheter (2).

[0059] In some embodiments, the tissue stabilizer element also provides embolic protection by ensuring that the resected tissue (speared by the catheter (1)) after cutting is captured and retained within the device assembly, thus allowing safe removal from the body by retracting the catheter (1), resected tissue, and (minimally retracted) tissue stabilizer back into the coaxially folded cutter as the cutter is retracted back into the lumen of the delivery catheter prior to removal from the right atrium and the body.

[0060] In some embodiments, as shown in FIGS. 12A and 12B, the tissue stabilizer (1204) is deployed from a catheter (1) (1201) that tracks along a guidewire (not shown) and takes the form of a balloon (1204) with a protective skirt (1207) that protects the proximal edge of the balloon while in the expanded configuration. This protective skirt expands and folds relative to the balloon's state. In some embodiments, the protective skirt or the like may serve at least two purposes, firstly, to protect the expanded tissue stabilizer from damage due to inadvertent contact with the cutter (1202) once deployed in the right atrium by unsheathing the delivery catheter (3) (1210), and secondly, to provide a wider or harder tissue stabilization surface. In some embodiments, the protective skirt comprises a single tine element; multiple tine elements; an expanding mesh; at least one bent wire; an expanding disk; an expanding fan; a spring coil; or at least one hinge arm. In some embodiments, the protective skirt expands and folds relative to the balloon's state. 12A and 12B are representative examples of exemplary embodiments of tissue stabilizers in the form of a balloon having a protective skirt to protect the proximal edge of the balloon while in a collapsed configuration and in the form of a balloon having a protective skirt to protect the proximal edge of the balloon while in an expanded configuration, the protective skirt expanding and collapsing relative to the state of the balloon.

[0061] 13A-13C are sequential representative examples of exemplary embodiments of tissue stabilizers in the form of tines that pass through the septum but cannot allow passage back into the original puncture after full deployment, where the tines are incorporated into the distal end of the catheter (1) and flatten in response to being pulled flush with the septum. In some embodiments, as shown in FIGS. 13A-13C, a device assembly (1300) disclosed herein includes a delivery catheter (3) (1310), and a tissue stabilizer (1307) that is deployed from the catheter (1) (1302) after its penetrating tip (1301) traverses the septum tracking along a guidewire (not shown), and that take the form of multiple tines (1307) that pass through the septum (1320) when they are deployed from the catheter (1) and expanded in an umbrella-like fashion, but cannot allow passage back into the original puncture after full deployment. The tines are configured to fit over the distal end of the unexpanded catheter (1) and be allowed to flatten against the left atrial side of the interatrial septum in response to being pulled flush with the septum. The tines extend or expand to a diameter less than the expanded diameter of the cutter (1308). In this embodiment, the tissue stabilizer is deformable under physical, chemical, biological factors, or a combination thereof. Additionally, the tissue stabilizer includes two or more umbrella bones in some embodiments.

[0062] FIG 14A is a representative view of an exemplary embodiment similar to that of FIGS 13A-13C, showing the tines partially penetrating the septum (with or without barbs at the end of each tine) to prevent the septum from migrating off the tines, where after cutting, the expanded struts allow for resheathing of the catheter over the tines and excised tissue, followed by removal of the device assembly from the body. FIG 14B is a representative view of an exemplary embodiment similar to that of FIGS 13A-13C, showing the tines partially penetrating the septum (with or without barbs at the end of each tine) to prevent the septum from migrating off the tines, where the process of resheathing into the delivery catheter bends the tines back so that the tissue and tines fit into the delivery catheter. FIG. 14C is another representative view of an exemplary embodiment similar to that of FIGS. 13A-13C , showing that the tines partially penetrate the septum (with or without barbs at the end of each tine) to prevent the septum from migrating off the tines, where the process of resheathing into the delivery catheter bends the tines back so that the tissue and tines fit into the delivery catheter when the delivery catheter is against the atrial septum.

[0063] In some embodiments, as shown in Figures 14A-14C, tissue stabilizer embodiments (1400) track along a guidewire (not shown) and are deployed from catheter (1) (1402) where they resume the form of multiple tines (1307) that pass through the septum as they are deployed from catheter (1) and expanded in an umbrella-like fashion. The tines partially penetrate the septum (1420) (with or without barbs at the end of each tine) to prevent the septum from dislodging from the tines. In all embodiments (with or without barbs on the tines), after a cutter (1408) is deployed from delivery catheter (3) (1410) and a portion of the atrial septum is resected, the expanded tines allow resheathing within the delivery catheter over the refolded tines and resected tissue (1403) as previously described, followed by removal of the device assembly from the body. In some embodiments, the process of resheathing the delivery catheter (1410) into the tines (1407) bends back so that the tissue and tines are easily pulled proximal to the delivery catheter. In this embodiment, the tissue stabilizer is deformable under physical, chemical, biological factors, or a combination thereof. Additionally, the tissue stabilizer includes two or more tines in some embodiments. Catheter (2) (1406) and piercing tip (1401) are also shown in Figures 14A-14C.

[0064] 15A-15E are sequential representative examples of exemplary embodiments of tissue stabilizers in the form of loops supported by shape-set tines. Catheter (1) (1502) includes a cap (1523) with a central lumen that houses the folded tissue stabilizer. Tissue stabilizer catheter (1524), slidably engaged with the outer diameter of catheter (1) (1502), is translated to its distal end (1501) and passes through the atrial septum to allow unsheathing of the catheter including the tissue stabilizer in the left atrium. In some embodiments, as shown in FIGS. 15A-15E, tissue stabilizer embodiment (1500) is folded and housed in catheter (1) (1502) with a piercing tip (1501), tracks along a guidewire (not shown), and takes the form of a loop supported by shape-set tines (1504) fabricated from a shape memory alloy or alloy. In some embodiments, the catheter (1) (1502) includes a cap (1522) and a shaft (1523). Figures 15A-15E are sequential representative examples of an exemplary embodiment of a tissue stabilizer in the form of a loop supported by shape-setting tines. The catheter (1) (1502) includes a cap (1523) where an additional catheter has a central lumen that houses the folded tissue stabilizer. The tissue stabilizer catheter (1524) is slidably engaged with the outer diameter of the tissue stabilizer-containing catheter (1) (1502) and translated to its distal piercing tip (1501), traversing the atrial septum and allowing unsheathing of the tissue stabilizer-containing catheter into the left atrium. After completion of tissue cutting, the expanded struts then allow the delivery catheter to be sheathed over the cutter (1508), extended struts (1504), and excised tissue (1503), followed by assembly and removal of the excised tissue from the body. In some embodiments, the tissue stabilizer takes the form of a rigid plate made of shape memory alloy or struts bridged by one or more shape memory alloys. The loops supported by the shape setting tines resemble various shapes, such as a tent shape with a base ring or an umbrella shape with a base ring.In this embodiment, catheter 1 1502 includes a puncturing distal tip 1501 that is unsheathed in the left atrium. Upon unsheathing of cap 1522, a series of tines supporting the loops expand to form expanded loops 1505 such that the tines resist any deformation beyond a 90 degree angle by the septum. The tines fold forward into catheter 1 1502 which houses them until deployment into the left atrium, where they expand within the left atrium to a range of 30 degrees to 90 degrees relative to the left atrial side of the atrial septum 1520. In some embodiments, the tines may be angled at a maximum of about 90 degrees, a maximum of about 80 degrees, a maximum of about 75 degrees, a maximum of about 60 degrees, a maximum of about 50 degrees, a maximum of about 45 degrees, a maximum of about 40 degrees, a maximum of about 35 degrees, a maximum of about 30 degrees, an angle between about 30 degrees and about 80 degrees, an angle between about 30 degrees and about 75 degrees, an angle between about 30 degrees and about 60 degrees, an angle between about 20 degrees and about 75 degrees, an angle between about 15 degrees and about 60 degrees, or an angle between about 15 degrees and about 60 degrees in the left atrium relative to the left atrial side of the atrial septum (1520). 30 degrees, about a 30 degree angle to about a 45 degree angle, about a 15 degree angle to about a 90 degree angle, up to a 90 degree angle, up to an 80 degree angle, up to a 75 degree angle, up to a 60 degree angle, up to a 50 degree angle, up to a 45 degree angle, up to a 40 degree angle, up to a 35 degree angle, up to a 30 degree angle, 30 degree to 80 degree angle, 30 degree to 75 degree angle, 30 degree to 60 degree angle, 20 degree to 75 degree angle, 15 degree to 60 degree angle, 30 degree to 45 degree angle, or 15 degree to 90 degree angle. This action is then followed by the deployment of the cutter (1508) from the delivery catheter (3) (1510) to create the anastomotic shunt (1521). After tissue cutting is completed, the excised tissue (1503) is captured between the cutter and the tissue stabilizer, and the expanded struts are then collapsed by the radial force applied by the cutter as the cutter is collapsed and resheathed in the delivery catheter in the manner described herein, followed by assembly and removal of the excised tissue (1503) from the body.

[0065] 59A-59E, in certain embodiments, after the device assembly is deployed in the right atrium, the tissue stabilizer containment catheter (5905), optionally with or without other elements enclosing the tissue stabilizer therein, is advanced into the left atrium and pulled proximally to unsheath one half (5904a) of the self-expanding oval-shaped clip in the left atrium, and optionally the other half (5904b) of the self-expanding clip is then unsheathed in the right atrium, thereby sandwiching the atrial septum (5920) therebetween. In this particular embodiment, the self-expanding clip is pivotable about a hinge point (5903) on the tissue stabilizer catheter (5902). In its folded state, the proximal clip is folded toward the proximal end of the device assembly and the distal clip is folded toward the distal end. In some embodiments, both clips face the same direction when folded and enclosed in the containment catheter. In some embodiments, two or more clips are positioned on each side of the septum to sandwich the tissue and improve tissue stabilization. Fig. 59A shows an exemplary sequential embodiment of an expandable tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer containing catheter is pulled back to unsheath one half of the self-expanding oval shaped clip at the left atrium and the other half at the right atrium, thereby sandwiching the atrial septum. Fig. 59B shows an exemplary sequential embodiment of an expandable tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer containing catheter is pulled back to unsheath one half of the self-expanding oval shaped clip at the left atrium and the other half at the right atrium, thereby sandwiching the atrial septum. FIG. 59C shows an exemplary sequential embodiment of an expandable tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer containing catheter is pulled back to unsheath one half of the self-expanding oval clip in the left atrium and the other half in the right atrium, thereby sandwiching the atrial septum therebetween.59D shows an exemplary sequential embodiment of an expandable tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer containing catheter is pulled back to unsheath one half of the self-expanding oval clip in the left atrium and the other half in the right atrium, thereby sandwiching the atrial septum. FIG. 59E shows an exemplary sequential embodiment of an expandable tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer containing catheter is pulled back to unsheath one half of the self-expanding oval clip in the left atrium and the other half in the right atrium, thereby sandwiching the atrial septum.

[0066] Further, in some embodiments, as shown in Figures 73A-73C, tissue stabilizer (7304) takes the form of a stiff plate made of shape memory alloy struts or a mesh made of lassos or petals. In this embodiment, catheter (1) (7301) containing the petals is translated through catheter (2) (7302) until its distal tip is unsheathed in the left atrium. Upon unsheathing the distal tip of catheter (1), a series of shape memory alloy struts are allowed to expand to a flat 90 degree angle at the septum in Figures 73A-73B relative to the shaft of the delivery catheter, ensuring capture and stabilization of the tissue during the cutting action. In some embodiments, these formed shape memory alloy struts, optionally connecting the petals, form an arc that bends away from the septum (7320) as it unsheathes to prevent capture on the lips of the cutter (7308) while allowing capture of the tissue, as shown in FIG. 73C. FIG. 73A shows an exemplary sequential embodiment of the tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer acts as a stiff plate when deployed, as it takes the form of a series of intertwined petals when exposed distally from the catheter in the left atrium, which would appear flat in cross section. FIG. 73B shows an exemplary sequential embodiment of the tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer acts as a stiff plate when deployed, as it takes the form of a series of intertwined petals when exposed distally from the catheter in the left atrium, which would appear flat in cross section. FIG. 73C shows an exemplary sequential embodiment of the tissue stabilizer of the device assembly as disclosed herein, where the tissue stabilizer takes the form of a series of intertwined petals when exposed distally from the catheter in the left atrium that would appear flat in cross-section, thus acting as a stiff plate when deployed.

[0067] 74A shows an exemplary sequential embodiment of a tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer consists of a series of radially self-expanding struts connected circumferentially by a series of shape memory bridges. In addition, there is an internal catheter (4) to the tissue stabilizer, which allows for the struts and connected bridges to be folded proximally after the septum has been cut and the resected tissue folded inside the folded struts and bridges.

[0068] 74B shows an exemplary sequential embodiment of a tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer consists of a series of radially self-expanding struts connected circumferentially by a series of shape memory bridges. In addition, there is an internal catheter (4) to the tissue stabilizer, which allows for the struts and connected bridges to be folded proximally after the septum has been cut and the resected tissue folded inside the folded struts and bridges.

[0069] 74C shows an exemplary sequential embodiment of a tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer consists of a series of radially self-expanding struts connected circumferentially by a series of shape memory bridges. In addition, there is an internal catheter (4) to the tissue stabilizer, which allows for the struts and connected bridges to be folded proximally after the septum has been cut and the resected tissue folded inside the folded struts and bridges.

[0070] 74D shows an exemplary sequential embodiment of a tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer consists of a series of radially self-expanding struts connected circumferentially by a series of shape memory bridges. In addition, there is an internal catheter (4) to the tissue stabilizer, which allows for the struts and connected bridges to be folded proximally after the septum has been cut and the resected tissue folded inside the folded struts and bridges.

[0071] As shown in Figures 74A-74D, in some embodiments, each of these struts can be bridged together by one or more shape memory alloy bridges (7401) to create a more uniform supported cutting surface on the septum (7420) for the cutter to make the cut. This then follows the expanded cutter, which in turn follows the coaxial catheter (2). After completion of the tissue cut, the expanded struts are stretched or collapsed to allow the catheter (2) (7402) to be sheathed over the stretched or collapsed struts and the excised tissue, followed by assembly and removal of the excised tissue from the body. In some embodiments, the shape memory alloy struts are sheathed by the catheter (2) which is connected to and travels over the catheter (1). In some embodiments, the shape memory alloy struts are connected to a catheter (1) and sheathed by a catheter (4) that travels through the catheter (1), which is housed in a delivery catheter (3) (7403) that traverses the septum to deploy the struts. The catheter (2) is deployed in the left atrium by translating the catheter (2) relatively distally relative to the catheter (1) allowing the struts to expand in the left atrium. This then follows the expanded cutter, which in turn follows the coaxial catheter (2). After tissue ablation is completed, the struts are folded back by translating the catheter (2) relatively proximally to the catheter (1) and, in the process, folding the resected tissue (7420) into a folded state within the struts of the catheter (1), as shown in FIG. 74D. After completion of packaging of the tissue and struts, the packaged struts and excised tissue allow the catheter (3) to be sheathed over the catheter (2), allowing subsequent removal of the assembly and the excised tissue from the body.

[0072] 75A-75E show an exemplary sequential embodiment of a tissue stabilizer of a device assembly as disclosed herein. Referring to Figs. 75A-75E, in certain embodiments, the catheter containing the tissue stabilizer is incorporated into a guide catheter (7501) that positions the tensioner toward the septum, optionally perpendicularly, thereby eliminating the need for a separate catheter that simply advances the tensioner. In some embodiments, the catheter containing the tissue stabilizer is a guide catheter. The catheter on which the tensioner is mounted is, in some embodiments, a braid catheter. In some embodiments, the OD of the catheter on which the tissue stabilizer is mounted is at the same height as the ID of the braid catheter. In this embodiment, the distal end of the catheter including the tensioner features slits (7503) numbered in the range of 2 to 20, each having a length of about 1-100 mm, about 1-50 mm, about 50-80 mm, about 1-30 mm, about 1-15 mm, about 15-40 mm, or about 25-55 mm, and a width of about 0.5-5.0 mm, about 0.5-1 mm, about 1-2 mm, about 2-3 mm, about 3-5 mm, about 1.5-3.5 mm, or about 2-4 mm. The tensioner, in some embodiments, is comprised of 2-20 struts (7504), each having a length of about 1-100 mm, about 1-50 mm, about 50-80 mm, about 1-30 mm, about 1-15 mm, about 15-40 mm, or about 25-55 mm, and a width of about 0.5-5.0 mm, about 0.5-1 mm, about 1-2 mm, about 2-3 mm, about 3-5 mm, about 1.5-3.5 mm, or about 2-4 mm. In some embodiments, the wall thickness of the struts is thicker or thinner than the wall thickness of the guide catheter or catheter containing the tensioner. In some embodiments, the width of the struts narrows into a notch (7505) at a midpoint along the length of the struts, as shown in FIG. 75B. In some embodiments, the width of the notch (7505) at the midpoint of the length of the strut is between about 1% and about 50%, between about 1% and about 25%, between about 25% and about 50%, between about 1% and about 15%, between about 15% and about 25%, between about 25% and about 35%, or between about 35% and about 50% less than the width of the strut beyond the notch.The notches have a length in the range of about 1-90 mm, about 1-50 mm, about 50-80 mm, about 1-30 mm, about 1-15 mm, about 15-40 mm, or about 25-55 mm. In some embodiments, the notches allow the strut to bend at its midpoint. In some embodiments, notches are also placed at the distal and proximal ends of the strut to reduce the amount of force required to radially deploy the strut.

[0073] In some embodiments, the catheter (catheter (1)) (7501) containing the tensioner is attached at its distal end to a second catheter (7502) that resides inside the catheter containing the tensioner. In some embodiments, the catheter (1) includes a series of helical cutouts at the distal end of the catheter (1) distal to the tensioner to facilitate secure attachment to the catheter (2). These helical cutouts, similar to the cutouts shown in FIG. 71, facilitate embedding of the catheter (2) into the catheter (1). The cutout design, in some embodiments, takes on alternative shapes; non-limiting examples include circular; square; rectangular; triangular; oval; polygonal; or any other feasible geometric shape. FIG. 71 illustrates an exemplary embodiment of a self-expanding blade of a device assembly as disclosed herein, where the proximal edge of the self-expanding blade has a series of helical cutouts to aid in secure attachment to the catheter.

[0074] In an unexpanded state, the catheter including the tensioner traverses the septum from the right atrium to the left atrium, as in Fig. 75 A. In some embodiments, the catheter including the tensioner is translated over a guidewire left in place from the transseptal puncture procedure.

[0075] In some embodiments, the tensioner is deployed once the full length of the struts (in the collapsed state) have traversed the septum into the left atrium. The tensioner is deployed by pushing catheter (1) (7501) over catheter (2) (7502), in some embodiments, as in FIG. 75C, to expand the struts outward into a flower-like shape (7506) as in FIGS. 75D-75E. The expanded struts, in some embodiments, are perpendicular in orientation to the septum and are stiff enough to resist bending more than 45° out of the radial plane. This helps prevent the struts from presenting a significant risk of being pulled through the septum, in some embodiments. In some embodiments, the tensioner is deployed by pulling catheter (2) towards catheter (1).

[0076] In some embodiments, each strut is covered at or around a notch at the midpoint of the strut with a coating of silicone, latex, rubber, polymer, fabric, shape memory alloy mesh, or combinations thereof. In some embodiments, the length of the coating ranges from about 1-100 mm, about 1-50 mm, about 50-80 mm, about 1-30 mm, about 1-15 mm, about 15-40 mm, or about 25-55 mm, and the width ranges from about 0.5-5.0 mm, about 0.5-1 mm, about 1-2 mm, about 2-3 mm, about 3-5 mm, about 1.5-3.5 mm, or about 2-4 mm. The coating helps prevent the septum from being punctured by the tips of the expanded struts. In some embodiments, the coating is applied along the entire length of the struts. In some embodiments, the coating is applied as one layer along the length of all the struts; as the tensioner struts expand, the coating expands to provide an "umbrella" effect.

[0077] In some embodiments, the struts feature one or more radiopaque markers that facilitate visualization of the tensioner throughout the procedure.

[0078] In some embodiments, the tissue stabilizer is made of stainless steel. In some embodiments, the tissue stabilizer, or similarly the tensioner, comprises a material other than stainless steel. Non-limiting examples of such materials include, but are not limited to, one or more of the following: a shape memory alloy or alloy, a shape memory polymer, aluminum, a polymer, a reinforced catheter, or a combination thereof.

[0079] In some embodiments, the tissue stabilizer (not shown) takes the form of a shape memory (e.g., shape memory alloy or metal) mesh that has one of two configurations throughout the procedure: a folded configuration (within catheter (4) prior to deployment into the left atrium) and a bulbous configuration (after deployment in the left atrium). Once catheter (4) is positioned within the left atrium, the tissue stabilizer is deployed through rearward movement of catheter (4) over catheter (1) (the catheter containing the tissue stabilizer). The tissue stabilizer is resheathed through forward movement of catheter (4) (over catheter (1)).

[0080] In some embodiments, tissue stabilization (not shown) is actuated by sandwiching the septum between magnets on either side of the septum. In this embodiment, catheter (4), which resides coaxially and translates between catheters (1) (the catheter housing the tissue stabilizer) and (2) (the catheter containing the expandable cutter), has a magnetic element about its distal tip. Catheter (5), which resides coaxially in catheter (1), has a magnetic element at its distal tip that expands radially upon movement from the tip of catheter (1) to enable tissue stabilization when the magnetic elements from catheters (5) and (4) are brought into close proximity.

[0081] In some embodiments, tissue stabilization (not shown) is actuated by sandwiching the septum between magnets on either side of the septum. In this embodiment, catheter (4), which is coaxial and translates between catheters (1) and (2), has a magnetic element around its distal tip. Catheter (1) has a gentle conical shape to allow for penetration of the septum and a flat proximal face to the conical shape to allow for tissue stabilization when sandwiching the septum between the magnetic elements on catheters (1) and (4).

[0082] Figure 16A is a representative view of an exemplary embodiment of a tissue stabilizer with an "umbrella type" mechanism in an undeployed state. Figure 16B is a representative view of Figure 16A in a deployed state, where the tissue stabilizer is deployed by the "umbrella" mechanism and an increase in the diameter of the stabilizing element is induced by translating the catheter to the tip of the catheter holding the tissue stabilizer, which in turn causes the two stiff struts to rotate together by bending at the hinge points where the two struts connect to the deployment catheter, to the holding catheter, and to each other.

[0083] In some embodiments, as shown in Figures 16A and 16B, the tissue stabilizer (1600) is deployed from a catheter (1) (1602) that follows along a guidewire with a piercing tip (1601) and is deployed via an "umbrella" mechanism (1618) while an increase in the diameter of the stabilizing element is caused by translating catheter (4) (1614) towards the tip of catheter (1) (1602), which in turn rotates two rigid struts (1618) up and together by bending the two struts at a live hinge point (1616) where they connect to catheter (4) (1614), catheter (1) (1602), and each other. The live hinge allows bending into the deployed state, but not beyond, and prevents the struts from bending beyond 90 degrees, ensuring tissue retention. In some embodiments, the hinges and hinge points (1616) allow bending to the deployed state, but not beyond, preventing the struts from bending beyond 90 degrees to ensure tissue retention.

[0084] In some embodiments, the tissue stabilizer (not shown) is formed of a stiff pigtail shaped catheter or wire that, once deployed, can withstand pulling through the septum and allows for tissue stabilization. In some embodiments, the tissue stabilizer comprises a balloon having a diameter in the range of 2 mm to 12 mm in the expanded state. In some embodiments, the balloon is fitted to provide protection against inadvertent puncture by a cutter or other part of the assembly.

[0085] In some embodiments, the tissue stabilizer is attached to a catheter (e.g., catheter (1)) or wire (guide wire or additional wire). In some embodiments, a tissue stabilizer delivery catheter (e.g., catheter (2)) is used to deliver the tissue stabilizer to the left atrium in its compacted state. In some embodiments, a stent blade cutter is attached to a "blade catheter" (e.g., catheter (3)). A delivery catheter (e.g., catheter (4)) houses the stent blade cutter in its compacted state. A guide catheter (e.g., catheter (5)) in some embodiments defines a path that the cutter takes from the mouth of the delivery catheter up to the septum and ensures coaxial alignment during cutting of the septum.

[0086] In some embodiments, the device assemblies disclosed herein include a shape memory alloy or metal catheter to provide tissue stabilization that provides a counter tension to the actuation of the cutter to minimize unintended tissue deformation, rotation, or displacement due to unbalanced forces. The tissue stabilizer element also, in some embodiments, prevents the resected tissue from inadvertently dislodging from the system and allows transfer of the resected tissue to the delivery catheter prior to removal of the device assembly from the body.

[0087] In some embodiments, the shape memory alloy mesh containing catheter holds the tissue stabilizer in a compact state prior to delivery to the left atrium, allowing for controlled deployment, as the tissue stabilizer is self-expanding in the disclosed form.

[0088] Referring to FIG. 54, in some embodiments, the shape memory alloy mesh catheter features one or more shape memory alloy mesh discs (5404a) distal to the one that contacts the septum (5404b) to 1) ensure that the resected (or partially resected) tissue (5420) does not become dislodged from the atrial septum and device assembly, and 2) to serve as a fail-safe to allow the blades to continue translating through the septum in the unlikely event that one of the shape memory alloy mesh plugs is inadvertently pulled through the septum before a full circumferential cut is completed, as shown in FIG. FIG. 54 shows an exemplary embodiment of a device assembly as disclosed herein, in which the shape memory alloy mesh catheter features one or more shape memory alloy mesh disks distal to the shape memory alloy mesh disk abutting the septum to 1) ensure that resected (or partially resected) tissue does not become dislodged from the atrial septum and the device, and 2) to serve as a fail-safe to allow the blades to continue translating through the septum in the unlikely event that one of the shape memory alloy mesh plugs is inadvertently pulled through the septum before a full circumferential cut has been completed.

[0089] FIG. 55A-B shows an exemplary embodiment of one or more shape memory alloy disks and their size relative to the cutter of a device assembly as disclosed herein. Referring to FIG. 55A-B, in some embodiments, the shape memory alloy mesh features one or more shape memory alloy disks distal to the tissue stabilization disk (5504b) that are sized larger than the diameter of the stent blades in both of their expanded states to act as a dock to prevent the stent blades from translating past the shape memory alloy mesh toward the left atrial free wall (or other cardiac anatomical features where cutting is undesirable), as shown in FIG. 55A. In this particular embodiment shown in FIG. 55A, the distal disk (5504a) is oversized to the expanded diameter of the blade or cutter (5508) to capture the penetrating tip of the blade after cutting is completed. FIG. 55B shows a third disk (5504c) that rests with the distal disk (5504b) against the septum (5520) in the right atrium, potentially pinching the septum to ensure that tissue does not dislodge from the assembly during or after the procedure to induce an embolic event. This proximal disk, as well as the distal disk that engages the septum (5504b), are sized down to the diameter of the stent blades in the expanded state.

[0090] Optionally, as shown in Figures 56A-56E, the shape memory alloy mesh in some embodiments assumes the form of various overlapping petals (5604) when sufficiently exposed to self-expand. Figures 56A-56E show an exemplary sequential embodiment of the deployment of the shape memory alloy mesh of the device assembly, where the delivered shape memory alloy mesh tissue stabilizer assumes the form of various overlapping petals. In some embodiments, the diameter of the shape memory alloy mesh increases in diameter along its length from the proximal edge in contact with the atrial septum towards its distal end; the distal diameter of the mesh (5704) is oversized with respect to the expanded diameter of the cutter (5708) to capture the tip of the cutter, as shown in Figure 57. Thus, FIG. 57 shows an exemplary embodiment of an expandable tissue stabilizer of a device assembly as disclosed herein, where the distal end of the frusto-conical (trapezoidal shaped) tissue stabilizer is too large for the expanded diameter of the blade to capture the penetrating tip of the cutter after the cut is completed.

[0091] FIG. 58A illustrates another exemplary sequential embodiment of an expandable tissue stabilizer of a device assembly as disclosed herein, where the delivered shape memory alloy mesh tissue stabilizer is folded into a flower-shaped pattern. FIG. 58B illustrates another exemplary sequential embodiment of an expandable tissue stabilizer of a device assembly as disclosed herein, where the delivered shape memory alloy mesh tissue stabilizer is folded into a flower-shaped pattern. FIG. 58C illustrates another exemplary sequential embodiment of an expandable tissue stabilizer of a device assembly as disclosed herein, where the delivered shape memory alloy mesh tissue stabilizer is folded into a flower-shaped pattern. FIG. 58D illustrates another exemplary sequential embodiment of an expandable tissue stabilizer of a device assembly as disclosed herein, where the delivered shape memory alloy mesh tissue stabilizer is folded into a flower-shaped pattern. Thus, in some embodiments, the shape memory alloy mesh expands in diameter by translating the proximal end of the string (5804) forward, as shown in Figures 58A-58D. Unlike Figures 75A-E, where longitudinal slits are cut to leave various struts behind one catheter, this embodiment includes strings connected at an angle. In this particular embodiment, as in Figures 58A-58D, the proximal end of the tissue stabilizer (5804) string is connected to catheter (1) (5801) which slides over catheter (2) (5802) which holds the string at its distal end, allowing the string to fold into a flower-like shaped pattern (Figure 58D) as catheter (1) (5801) is moved towards the distal end of catheter (2) (5802). Because the string is connected at an angle, it forms the shape of a petal. In some embodiments, the proximal end of the string is attached to the distal end of the catheter (1) and the distal end of the string is attached to a catheter (2) that is moved proximally within the internal lumen of the catheter (1), thereby allowing the string (5804) to fold into a flower or petal shaped pattern (5806).

[0092] 72A shows an exemplary sequential embodiment of a tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer is a shape memory alloy mesh that is expanded by translating the proximal and distal edges toward one another to form a disk that sandwiches the septum during translation. FIG. 72B shows an exemplary sequential embodiment of a tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer is a shape memory alloy mesh that is expanded by translating the proximal and distal edges toward one another to form a disk that sandwiches the septum during translation. FIG. 72C shows an exemplary sequential embodiment of a tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer is a shape memory alloy mesh that is expanded by translating the proximal and distal edges toward one another to form a disk that sandwiches the septum during translation. Thus, in some embodiments, the shape memory alloy mesh expands in diameter by translating the proximal and distal edges toward each other, as shown in Figures 72A-72C, and during translation, the two disks of shape memory alloy mesh sandwich the septum. Referring specifically to Figures 72A-72C, the shape memory alloy mesh (7204) is advanced such that in this embodiment, the distal portion of the mesh is in the left atrium connected to catheter (1) (7201) and the proximal portion of the mesh resides in the right atrium connected to catheter (2) (7202) prior to unsheathing of the mesh. Due to the unsheathing, the proximal portion of the mesh (7204b) is pushed toward the septum (7220) by translating catheter 2 distally, while the distal portion of the mesh (7204a) remains relatively fixed against the septum by moving catheter (1) proximally toward the septum. Such movement of the distal or proximal portions of the mesh results in a decrease in dimension along the proximal-distal direction, but expansion in a direction that is approximately perpendicular (at an angle in the range of 75-105 degrees) to the proximal-distal direction (or to the axis of a nearby guide, containment, or delivery catheter) to the septum, forming two disks (7204a) (7204b) that sandwich the septum.

[0093] In some embodiments, the shape memory alloy tissue stabilizer is in a crimped configuration similar to a stent compressed in a crimped configuration; in a deployed state, it sandwiches the atrial septum between a mesh disk, valve, or plug; and is deployed as described in FIG. 42A-F. FIG. 42A-F shows an exemplary embodiment of a sequential process using a device assembly as described herein, resulting in the deployment of a dog-bone shaped expandable tissue stabilizer to sandwich the atrial septum. Some embodiments do not require the introduction of a tissue stabilizer-containing catheter similar to FIG. 38A-D, or even the tissue stabilizer-containing catheter similar to FIG. 60A-60D. FIG. 38A-D shows an exemplary sequential embodiment of a device assembly as described herein, eliminating the need for an additional mesh-containing catheter to deploy the tissue stabilization element as the guide catheter has a smaller OD at the distal end to ensure it passes through the atrial septum while extending over the guidewire. 60A-60D, in an exemplary embodiment, guide catheter (1) (6002) has a predetermined bend and includes self-expanding tissue stabilizers (6004a) (6004b) that are deployed in both the left and right atria by proximally pulling a catheter (6005) that also houses the tissue stabilizer along with the guide catheter. FIG 60A shows an exemplary sequential embodiment of the tissue stabilizer of a device assembly as disclosed herein, where the guide catheter has a predetermined bend and includes a self-expanding tissue stabilizer that is deployed in both the left and right atria by proximally pulling back a catheter that also houses the tissue stabilizer as well as the guide catheter. FIG. 60B shows an exemplary sequential embodiment of the tissue stabilizer of the device assembly as disclosed herein, where the guide catheter has a predetermined bend and is equipped with a self-expanding tissue stabilizer that is deployed in both the left and right atria by proximally retracting the catheter housing the tissue stabilizer as well as the guide catheter.Figure 60C shows an exemplary sequential embodiment of a tissue stabilizer of a device assembly as disclosed herein, where the guide catheter has a predetermined bend and includes a self-expanding tissue stabilizer that is deployed in both the left and right atria by proximal retraction of the catheter housing the tissue stabilizer as well as the guide catheter. Figure 60D shows an exemplary sequential embodiment of a tissue stabilizer of a device assembly as disclosed herein, where the guide catheter has a predetermined bend and includes a self-expanding tissue stabilizer that is deployed in both the left and right atria by proximal retraction of the catheter housing the tissue stabilizer as well as the guide catheter.

[0094] FIG. 61A shows an exemplary sequential embodiment of a tissue stabilizer of a device assembly as disclosed herein, where once the catheter housing the tissue stabilizer is pulled back to unsheath the mesh, a proximal portion of the self-expanding mesh is connected to a first ring that allows it to translate toward the distal end of the catheter containing the tissue stabilizer. A second ring attached to the catheter containing the tissue stabilizer and positioned near the tissue stabilizer acts as a stop for the first ring that is connected to the self-expanding mesh. The self-expanding mesh can translate over the second ring; however, the ID of the first ring is sized smaller relative to the OD of the second ring. FIG. 61B shows an exemplary sequential embodiment of a tissue stabilizer of a device assembly as disclosed herein, where once the catheter housing the tissue stabilizer is pulled back to unsheath the mesh, a proximal portion of the self-expanding mesh is connected to a first ring that allows it to translate toward the distal end of the catheter containing the tissue stabilizer. A second ring attached to the catheter containing the tissue stabilizer and positioned near the tissue stabilizer acts as a stop for the first ring connected to the self-expanding mesh. The self-expanding mesh can translate over the second ring; however, the ID of the first ring is sized smaller relative to the OD of the second ring. Thus, referring to FIGS. 61A-61B, specifically, the self-expanding tissue stabilizer (6104) has a stiff inner element (6107) attached to the catheter (1) (6102) containing the tissue stabilizer at its distal end. The proximal end of the nitinol mesh is connected to a ring that is slidably engaged with the catheter (1) (6102), where the ring (6109) can move distally as the nitinol mesh self-expands over the ring after unsheathing. In this particular embodiment, optionally after the proximal end of the mesh is advanced into the left atrium, the proximal end translates toward the rigid element (6107), while the distal end optionally remains fixed relative to the rigid inner element, thereby allowing the mesh to self-expand into a disk, valve, or plug-like shape.A stiff inner element is attached to the catheter (6102) and has an OD larger than the ID of the ring (6109) to prevent the ring from translating more distally after unsheathing. The expanded stabilizer is then pulled back to contact the septum (6120) for stabilization during tissue resection in some embodiments.

[0095] In some embodiments, the shape memory alloy mesh (6104) is advanced such that the distal portion of the mesh is in the left atrium and the proximal portion of the mesh remains in the right atrium prior to unsheathing of the mesh. For unsheathing, the proximal portion of the mesh (7204b) is pushed toward the septum (7220) in some embodiments while the distal portion of the mesh remains relatively fixed relative to the septum or moves proximally toward the septum, as shown in FIGS. 72A-72C. Such movement of the distal or proximal portion of the mesh results in a reduction in size along the proximal-distal direction but an expansion in a direction that is approximately perpendicular (having an angle in the range of 75-105 degrees, or 80-100 degrees) to the proximal-distal direction (or to the axis of a nearby guide catheter, containment catheter, or delivery catheter) to the septum, forming two disks (7204a) (7204b) that sandwich the septum.

[0096] In some embodiments, the shape memory alloy tissue stabilizer is similar to a stent compressed in a crimped state; in a deployed state, it sandwiches the atrial septum between its struts; it is deployed as described in FIG. 42A-F and FIG. 44A-F; and its proximal portion is connected to the distal portion of a guide catheter. FIG. 62 shows an exemplary embodiment of a tissue stabilizer of a device assembly as described herein, in which a self-expanding mesh disk has only a concave surface that allows the outer edge of the mesh to touch the atrial septum to help prevent the mesh disk from being pulled through the atrial septum. Thus, in some embodiments, as shown in FIG. 62, the shape memory alloy tissue stabilizer (6204) has a concave surface on its proximal side that only allows the outer edge of the mesh to contact the atrial septum (6220). Because the stabilizer is deformable, in some embodiments, it further stretches to a larger diameter so that the concave surface flattens to help prevent the mesh disk from being pulled through the atrial septum. In this particular embodiment, the disc (6204) remains in contact with the septum (6220) while traction or other proximally directed force is applied upward toward a threshold value, after which the concave surface flattens out or becomes convex such that the disc (6204) is resheathed after the procedure with the device assembly herein is completed.

[0097] In some embodiments, a shape memory alloy self-winding wire (6304a) is present wound around the catheter (1) (6302) and when the device assembly is not deployed, the proximal end of the wire is connected to a catheter (6305) that is rotated or moved distally from the septum (6320) in the left atrium, thereby rotating or moving the proximal end of the wire distally. Such coiling, uncoiling, or distal movement then causes the wire to unwind or expand the tissue stabilizer through the well at the distal end of the catheter (1). Such coiling, uncoiling, and distal movement then causes the wire to unwind or expand the tissue stabilizer through the well at the distal end of the catheter (1). The catheter (1) includes a distal end of the wire, optionally connected to the distal end of the wire, as shown in Figures 63A-63D, and takes the shape of a mesh of flowers or petals (6304b). Figure 63A shows an exemplary sequential embodiment of a tissue stabilizer of a device assembly as described herein, where a self-coiling wire is wrapped around and placed in a catheter (1) whose proximal end is connected to a catheter that is rotated and moved distally to either unwind the wire or expand the tissue stabilizer through a deep hole in the distal end of the catheter (1). Figure 63B shows an exemplary sequential embodiment of a tissue stabilizer of a device assembly as described herein, where a self-coiling wire is wrapped around and placed in a catheter (1) whose proximal end is connected to a catheter that is rotated and moved distally to either unwind the wire or expand the tissue stabilizer through a deep hole in the distal end of the catheter (1). FIG. 63C shows an exemplary sequential embodiment of a tissue stabilizer of a device assembly as described herein, where a self-wound wire is wound and placed within a catheter (1) whose proximal end is connected to the catheter, which is rotated and moved distally to unwind the wire or expand the tissue stabilizer through a deep hole in the distal end of the catheter (1).FIG. 63D shows an exemplary sequential embodiment of a tissue stabilizer of a device assembly as described herein, where a self-wound wire is wound and placed within a catheter (1) whose proximal end is connected to the catheter, which is rotated and moved distally to unwind the wire or expand the tissue stabilizer through a deep hole in the distal end of the catheter (1).

[0098] In some embodiments, the balloon catheter (6404b) (6504b) is coaxially housed within the shape memory alloy mesh catheter (6404a) (6504a) as shown in Figures 64-65 and is sized smaller than the diameter of the blade and optionally the cutter when expanded, such that the internal balloon, when inflated, prevents the shape memory alloy mesh from inadvertently folding during the cutting action and provides a second stabilizing support to the interior of the shape memory alloy mesh. Figure 64 shows an exemplary side view embodiment of a tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer includes a self-expanding mesh disk surrounding a small balloon that, once inflated, prevents the tissue stabilizer from being pulled through the atrial septum toward the right atrium. FIG. 65 illustrates an exemplary end view embodiment of a tissue stabilizer of a device assembly as shown in FIG. 64 and disclosed herein, where the tissue stabilizer includes a self-expanding mesh disk surrounding a small balloon that, once inflated, prevents the tissue stabilizer from being pulled through the atrial septum toward the right atrium. The balloon (6404b) (6504b), in some embodiments, is inflated with gas, fluid, or other possible forms of filling. In this particular embodiment, the balloon is a diameter smaller than the cut diameter of the septum, the expanded diameter of the mesh, and the expanded diameter of the blades. In some embodiments, the balloon is a diameter equal to or greater than the cut diameter of the septum, the expanded diameter of the mesh, and the expanded diameter of the blades. In some embodiments, such diameters are at or approximately perpendicular (having an angle ranging from 75-105 degrees or 80-100 degrees) to the proximal-distal direction (or axis) of the nearby guide catheter, containment catheter, or delivery catheter.

[0099] 64 and 65, in these embodiments, the self-expanding shape memory alloy element takes the form of a self-expanding mesh disk (6404a)(6504a) that, once inflated, surrounds a small balloon (6404b)(6504b) that prevents the tissue stabilizer from being pulled through the atrial septum toward the right atrium in its deployed state; such self-expanding mesh disk (6404a)(6504a) unfolds when the guide or containment catheter is moved into the right atrium and the balloon expands, thereby expanding the mesh in the left atrium. In some embodiments, the outermost edge is a diameter sized slightly under the expanded diameter of the cutter to provide adequate stabilization during cutting.

[0100] In some embodiments, the self-expanding shape memory alloy element assumes the form of one large coil upon expansion by advancing it over the containment catheter in the left atrium, as shown in FIG. 66. FIG. 66 illustrates an exemplary embodiment of a tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer is a self-expanding coil. Referring to FIG. 66, in certain embodiments, such a coil (6604) is expanded when the guide catheter or containment catheter is moved proximally, thereby unsheathing the coil. In some embodiments, the outermost edge is a diameter sized slightly smaller than the expanded diameter of the cutter to provide adequate stabilization during cutting. In some embodiments, the expanded coil is folded back into the catheter after tissue resection by movement of the coil toward the distal end of the catheter. In some embodiments, the coil is at or approximately perpendicular (having an angle ranging from 75-105 degrees or 80-100 degrees) to the proximal-distal direction (or axis) of the nearby guide catheter, containment catheter, or delivery catheter. In some embodiments, the center of the expanded coil is on the same axis as the center of the distal cross section of the guide catheter, containment catheter, or delivery catheter.

[0101] In some embodiments, one or more of the self-expanding shape memory alloy elements assume the form of a hemisphere (6704a) upon expansion by being exposed from the containment catheter in the left atrium in FIG. 67. FIG. 67 illustrates an exemplary embodiment of a tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer includes one or more self-expanding disks and one or more self-expanding hemispherical mesh plugs. In some embodiments, the elements are distal to one or more shape memory alloy stabilizing elements (6704b) (6704c) that are in contact with the septal wall. In some embodiments, the shape memory alloy mesh when deployed across the septum assumes the form of a shape memory alloy stabilizing dumbbell (6804a) (6804b) in FIG. 68 that pinches the septum and stabilizes it during the cutting operation. 68 shows an exemplary embodiment of a tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer includes two self-expanding hemispherical plugs on each side of the atrial septum, with the flat sides of the hemispheres facing the atrial septum. In some embodiments, the shape memory alloy tissue stabilizer is similar to a compressed stent in a crimped state; in a deployed state, it sandwiches the atrial septum between the disks, valves, plugs, or hemispheres; it is deployed as described in FIG. 42 AF; its proximal portion is connected to the distal portion of a guide catheter.

[0102] In some embodiments, in Figs. 69A-69B, the shape memory alloy mesh has self-wound wires therein upon additional deployment to provide additional radial loose stiffness and prevent accidental folding of the shape memory alloy mesh during the cutting action, stabilizing it during the cutting action. Fig. 69A shows an exemplary sequential embodiment of a tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer comprises a self-expanding hollow mesh filled with self-wound wires. Fig. 69B shows an exemplary sequential embodiment of a tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer comprises a self-expanding hollow mesh filled with self-wound wires. Thus, referring to Figures 69A-69B, when the mesh (6904a) is deployed by pulling the catheter (1) (6902) into the right atrium, the self-coiling wire (6904b) is affected by the centrifugal movement of the wire relative to the shape memory alloy mesh catheter (6904) containing the mesh (6904a), thereby correspondingly unsheathing and coiling the wire, thereby reinforcing the mesh and providing additional radial loose stiffness and preventing accidental folding of the shape memory alloy mesh during the cutting operation. In some embodiments, the self-expanding element comprises a series of shape memory alloy wires connected at both ends such that when allowed to self-expand, they assume the shape of an oblate sphere, as shown in Figures 70A-70B. Figure 70A shows an exemplary side and front view embodiment of a tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer is a self-expanding oblate sphere. 70B shows an exemplary side and front view embodiment of a tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer is a self-expanding oblate sphere. Referring to FIG. 70A-70B, when the mesh catheter (7004) is deployed, the proximal end of the shape memory alloy wire (7004a) is also affected by a centrifugal movement relative to the wire-containing catheter (1) (7002), thereby correspondingly unsheathing and bending the wire, thereby forming an oblate sphere as shown in FIG.70A shows an exemplary side and front view embodiment of a tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer is a self-expanding oblate sphere. FIG. 70B shows an exemplary side and front view embodiment of a tissue stabilizer of a device assembly as disclosed herein, where the tissue stabilizer is a self-expanding oblate sphere.

[0103] In some embodiments, the balloon aspect of the balloon catheter is fitted to provide protection against inadvertent puncture by the cutter. In some embodiments, the balloon is a cryoballoon that uses cryoablation to freeze a portion of the septum targeted to the proximal edge of the balloon to prevent it from escaping from the control of the device assembly. In some embodiments, the tissue stabilizer material for everything other than the inflatable balloon includes a shape memory alloy, including nickel-titanium, copper-aluminum-nickel, zinc-gold-copper, or combinations thereof. In some embodiments, the tissue stabilizer, or similar tensioning element, includes a material other than a shape memory metal or alloy. Non-limiting examples of such materials include, but are not limited to, one or more of stainless steel, reinforced catheters, polymers, or combinations thereof.

[0104] In some embodiments, the expanded dimension of the tissue stabilizer is slightly less than the expanded dimension of the cutter to allow tissue tenting of the atrial septum such that the cutter creates an opening larger than the expanded dimension of the cutter. In some embodiments, the expanded dimension of the tissue stabilizer is less than about 1%, about 5%; about 10%; about 15%; about 20%; about 25%; about 30%; about 35%; about 40%; about 45%; about 50%; or about 75% of the expanded dimension of the cutter. In some embodiments, the expanded dimension of the tissue stabilizer is measured at or near the distal end or at or near the proximal end of the tissue stabilizer. In some embodiments, the expanded dimension of the cutter is measured at or near the distal end or at or near the proximal end of the cutter. In some embodiments, the expanded dimension of the tissue stabilizer is approximately equal to or slightly greater than the expanded dimension of the cutter to occlude the distal end of the expanded cutter to retain the resected tissue. In some embodiments, the expanded dimension of the tissue stabilizer is about 0.1% to about 15% greater than the expanded dimension of the cutter. In some embodiments, optionally, when more than one expandable mesh element is positioned in the left atrium, the expanded dimension of the tissue stabilizer at the distal end is about 5%, about 10%, about 15%, about 20%, about 25%, or about 30% greater than the expanded dimension of the cutter to prevent the incisors from inadvertently injuring structures other than the septum.

[0105] In some embodiments, when the delivery catheter is pulled proximally with the distal end of the second coaxial catheter, dragging it along, the tissue stabilizer, cutter, is configured to radially expand coaxially within the left atrium to its intended dimension, where the distal end of the delivery catheter is further pulled back within the right atrium to allow the tissue stabilizer to radially expand to a sufficiently large dimension, where the outer expanded dimension of the cutter (e.g., expanded OD) is less than the inner dimension (expanded ID) of the expanded tissue stabilizer, and where the radially expanded dimension of the tissue stabilizer provides a supportive and pulling effect on the right atrial side of the atrial septum around the initial puncture site.

[0106] In some embodiments, the coaxial alignment mechanism provides centralization between the cutter, tissue stabilizer, and tissue retaining element. In some embodiments, the coaxial alignment mechanism provides centralization between the cutter, tissue stabilizer, or tissue retaining element. In some embodiments, the coaxial aligner reduces the risk of inadvertent interaction between the cutter and tissue stabilizer (such as when catheter (1) translates proximally to catheter (2) or (3) or (4)). The coaxial aligner also serves as a means to ensure that the cutter (coupled to catheter (2)) is advanced centrally onto catheter (1) and through the septum. In some embodiments, the coaxial aligner also serves as a means to ensure that preformed elements such as bent guidewires or shape memory alloy stabilizers remain straight during the initial placement phase, and also act as a "straightener" or "folding mechanism" when the bent guidewire or shape memory alloy stabilizer element is retracted into the catheter.

[0107] Figure 17 is a representative illustration of an exemplary embodiment of a coaxial alignment mechanism achieved by the outer diameter (OD) of catheter (1) and the inner diameter (ID) of horizontal catheter (2), and the ID of catheter (3) and the OD of horizontal catheter (2). In some embodiments, as illustrated in Figure 17, the coaxial alignment mechanism (1700) is achieved by the outer diameter (OD) of catheter (1) (1702) on which tissue stabilizer (1704) rests and the inner diameter (ID) of horizontal catheter (2) (1706), and the ID of catheter (3) (1710) and the OD of horizontal catheter (2) (1706). In any of the embodiments described herein, the inner or outer diameter of catheter (1), catheter (2), catheter (3), catheter (4), or combinations thereof, has a hydrophilic or hydrophobic coating. In any of the embodiments described herein, the inner and outer diameters of catheter (1), catheter (2), catheter (3), catheter (4), or combinations thereof, have a hydrophilic or hydrophobic coating. Figure 17 further shows a cutter (1708).

[0108] FIG. 18 is a representative example of an exemplary embodiment of a device assembly, taking the form of the previous embodiment of FIG. 17, except that the ID of catheter (2) has been modified at its distal surface to create a space between catheter (1) and catheter (2) that serves as a tissue retention pocket. In some embodiments, as illustrated in FIG. 18, device assembly (1800) takes the form of the previous embodiment, including catheter (2) (1806) that is level with the outer diameter (OD) of catheter (1) (1802) on which tissue stabilizer (1804) rests, and the OD of catheter (2) (1806) is level with the ID of catheter (3) (1810); except that the ID of catheter (2) (1806) has been modified at its distal portion to create a space between catheter (1) (1802) and catheter (2) (1806) that serves as at least a tissue retention pocket. In some embodiments, the resected tissue is then easily translated into catheter (2) prior to removal of the system from the body. In some embodiments, the OD of catheter (2) in the coaxial arrangement of the previously described embodiment is not level with the ID of catheter (3). In some embodiments, the resected tissue is translated into catheter (2) prior to removal of the system. In some embodiments, the OD of catheter (2) in the coaxial arrangement of the previously described embodiment is not level with the ID of catheter (3). In some embodiments, an additional catheter (4) (coaxial with catheter (1)) having an ID level with the OD of catheter (1) and an OD level with the ID of catheter (2) is used to provide a coaxial arrangement along its length. FIG. 18 further shows a cutter (1808).

[0109] In some embodiments (not shown), a catheter (4) (coaxial with catheter (1)) whose ID is parallel to the OD of catheter (1) and whose OD is parallel to the ID of catheter (2) provides coaxial alignment along its length.

[0110] 19 is a representative illustration of an embodiment of catheter (2) (1914) (coaxial with catheter (1) (1902)) with an ID level with the OD of catheter (1) (1902). Catheter (2) includes a proximally thickened wall to enable coaxial alignment along its length (1906), where the OD is level with the ID of catheter (1907), and has an increased diameter at its distal edge (1908) to help stabilize the tissue during the cutting process. In some embodiments (1900), as illustrated in FIG. 19, catheter (2) (1914) includes a second tissue stabilizing element (1909) to aid in tissue capture during the cutting process (coaxial with catheter (1) (1902)), with its ID level with the OD of catheter (1) (1902), which further includes a piercing tip (1901) and a first tissue stabilizing element (1904). Catheter (2) includes a proximally thickening wall that allows for coaxial alignment along its length (1906), where the OD is level with the ID of the catheter (1907) that includes the cutter. Catheter (2) (1914) (1906) is transferable between catheter (1) (1902) and catheter (1907). The catheter (1907) containing the cutter (1908) also has an increased ID at its distal end to aid in tissue capture and removal during the device assembly withdrawal process. FIG. 19 also shows the delivery catheter (3) as (1910). The tissue stabilizing element (1904) is stored in its collapsed state in the ID of the catheter (2) prior to expansion in the left atrium. A second tissue stabilizing element, positioned proximal to the septum (1920) of the right atrium, is stored in its collapsed state in the catheter (1907). In some embodiments, an additional catheter is used to store the second tissue stabilizing element (1909). This additional catheter is between the OD of the catheter (2) and the ID of the catheter (3).

[0111] In some embodiments, the device assemblies disclosed herein include a cutter, a cutter, a blade, multiple blades, or the use thereof. The cutter (coupled to the catheter (2)), in some embodiments, includes an annulus or scaffold and features at least one bladed edge at its distal tip. In some embodiments, the cutter is delivered to the atrial septum and upon deployment and actuation, incises a portion of the atrial septum to create an opening (anastomotic shunt). The bladed edge assumes a form factor that reduces the amount of force required to propel the cutter through the septum.

[0112] Figure 20 shows a representative illustration and multiple views of one embodiment of a cutter, where the cutter takes the form of an expandable lattice / stent made of a self-expanding material (i.e.: shape memory alloy; e.g., Nitinol), has a proximal end attached to the distal end of a catheter (2) (the catheter containing the expandable cutter), and a distal portion sharpened to produce one or more cutting blades. In some embodiments, as illustrated in Figure 20, the cutter (2000) described herein takes the form of an expandable lattice or equivalent stent (2001), (2002), (2004) made of a self-expanding material (e.g., shape memory alloy or metal), has a proximal end attached to the distal end of a catheter (2), and its distal portion is sharpened to produce one or more cutting blades (2008), as illustrated in detail "A" of Figure 20. The cutter's lattice or equivalent stent cell structure or geometry allows the cutter to collapse to a smaller diameter in a collapsed state to minimize the risk of vessel diameter complications during insertion while resisting deformation in radius or length during the cutting action in the expanded state.

[0113] Upon delivery to the site of the atrial septum where the procedure will be performed, the cutter is deployed and simultaneously expanded to a diameter greater than the catheter through which it is inserted. The distal end of the cutter includes multiple teeth distributed circumferentially or radially, for example as shown in detail "A" of FIG. 20, with the tip of each blade having a sharp acute angle (e.g., 0°-90° in its fully expanded state). This configuration allows for easy penetration of tissue with multiple perforating blades forming a closed circumference, figure or shape. With the bladed teeth, the force required for tissue disruption can be significantly less than that required by a planar or flat blade with one continuous acute angle.

[0114] In some embodiments, the sharp end resembles one or more of a wavy tooth or a straight tooth, where the tip of the tooth is either pointed or rounded or a combination thereof, and the root of the tooth is either pointed or rounded or a combination thereof. In some embodiments, the expandable cutter includes a continuous blade including a shape memory alloy, and the distal end of the continuous blade includes a single smooth sharp knife blade configured to function as a continuous tissue-cutting blade; or multiple sharp serrations or teeth along the continuous blade. In some embodiments, the single smooth sharp knife blade or multiple sharp serrations along the continuous blade are configured to operate as a complete circumferential (continuous) tissue-cutting blade. In some embodiments, the expandable cutter is configured to enter and cut through the atrial septum. In some embodiments, the multiple sharp serrations along the continuous blade resemble one or more of a wavy tooth or a straight tooth, where the tip of the serration is either pointed or rounded or a combination thereof, and the root of the serration is either pointed or rounded or a combination thereof.

[0115] Minimizing the force required to create an opening is advantageous because the force required to penetrate tissue without excessive load on the bladed cutter, delivery catheter, or surrounding vessels must be translated along the length of the entire catheter system. In some embodiments, serrated and wavy blades are used, which cut soft, pliable tissue without tearing or cutting, thus reducing load on the catheter system and potential damage to the soft tissue surrounding the heart. In some embodiments, serrated or wavy blades are used, which cut soft, pliable tissue without tearing or cutting, thus reducing load on the catheter system and potential damage to the soft tissue surrounding the heart. In some embodiments, this becomes important when multiple cuts are required with a single-use device assembly.

[0116] In some embodiments, the distal edge of the cutter has many serrations or teeth and forms an opening that is polygonal in cross section. Note that as more teeth are radially arranged, the resulting orifice shape more closely approximates the area of ​​a circle. One of skill in the art will recognize upon reading this disclosure that the distal shape of the cutter can be configured with a variable number of serrations or teeth, ranging from 3 serrations or teeth to 20 or more serrations or teeth. As catheter (2) exits catheter (3) through proximal movement of catheter (3) or pushing catheter (2) forward, in some embodiments, the cutter self-expands to assume its original expanded state (maximum diameter).

[0117] In some embodiments, the cutter includes one or more types of shape memory alloys to facilitate its proper functionality. In some embodiments, the material of the cutter includes a shape memory alloy or metal. Non-limiting examples of shape memory alloys or metals include: nickel-titanium; copper-aluminum-nickel; zinc-gold-copper; or combinations thereof. In some embodiments, the cutter includes: a wire mesh; a wire connecting sharp teeth; a collapsible hole saw configuration; a collapsible open-ended cylindrical configuration; a collapsible open-ended barrel-shaped configuration; a collapsible open-ended cone-shaped configuration; or combinations thereof. In some embodiments, the cutter is configured such that the cutting teeth of the cutter include: a single wire that is sharpened; a single-edged blade configuration; a double-edged blade configuration, or a double-edged scissor blade; an inverted "v" shape; or a "u" shape (or wavy shape), where the distal ends of all teeth are the cutting edges and cutting edges of the cutting teeth, and when combined, are configured to cut a complete opening when the cutter completely passes through the atrial septum.

[0118] In some embodiments, the thickness of the cutter wall is about 0.1 mm to about 0.5 mm. In some embodiments, the thickness of the cutter wall is in the range of 0.005 to 0.6 mm. In some embodiments, the thickness of the cutter wall is about 0.01 mm to about 0.8 mm. In some embodiments, the cutter has multiple separate points, or even tips, at its distal end. In some embodiments, the number of tips is 3 to 12. In some embodiments, the distal end of the cutter is considered to be a single edge with multiple pointed or sharp tips. In some embodiments, the distal end of the cutter is also considered to be multiple blades connected together with or without a sharp blade between them. In some embodiments, the OD at the distal end or tip of the cutter is less than about 8.0 mm in its folded state. In some embodiments, the OD at the distal end or tip of the cutter, in its open state, is about 5.0 mm to about 12.0 mm, about 3 mm to about 5 mm, about 6 mm to about 9 mm, about 7 mm to about 9 mm, about 8 mm to about 12 mm, about 9 mm to about 14 mm, or about 3 mm to about 14 mm. In some embodiments, open cutters having an OD disclosed herein can have a maximum diameter of up to 200 mm. 2 , max. 180mm 2 , maximum approximately 160mm 2 , maximum approximately 140mm 2 , maximum about 120mm 2 , maximum approx. 100 mm 2 , maximum about 80mm 2 , maximum about 60mm 2 , maximum about 40mm 2 , maximum about 20mm 2 , maximum about 10mm 2 , maximum about 5mm 2 , about 5mm 2 ~about 10mm 2 , about 5mm 2 ~about 20mm 2 , about 10mm 2 ~about 20mm 2 , about 15 orientation angle ~ about 30 mm 2 , about 20mm 2 ~ approx. 40mm 2 , about 30mm2 ~about 45mm 2 , about 35mm 2 ~ approx. 50mm 2 , approx. 40mm 2 ~about 60mm 2 , about 50 mm 2 ~about 70mm 2 , about 60mm 2 ~about 80mm 2 , about 70mm 2 ~about 90mm 2 , about 80mm 2 ~approx. 110mm 2 , about 90mm 2 ~approx. 130mm 2 , about 100 mm 2 ~about 150mm 2 , 35mm 2 ~65mm 2 , 40mm 2 ~75mm 2 , 45mm 2 ~80mm 2 , 50mm 2 ~85mm 2 , 20mm 2 ~60mm 2 , 30mm 2 ~80mm 2 , or 35mm 2 ~65mm 2In some embodiments, the cutter includes a stent lattice in its expanded state, transitioning in an S-shape from a small diameter (e.g., less than about 4.0 mm) at its proximal end to a larger diameter (e.g., about 5.0 to about 10.0 mm (having a range of 3 mm to 12 mm)) at its distal end. In some embodiments, the distal lattice cells, the distal tip, or both, are parallel to the proximal end of the cutter attached to the catheter (2) and straight in its expanded state, as can be seen in FIG. 36. FIG. 36 is an exemplary embodiment of a device assembly illustrating multiple shape memory alloy disks advanced through one or more catheters. Referring to FIG. 36, in certain embodiments, the assembly, here an additional inner guide catheter (3603), has a predetermined but flexible curvature and is external to the inner catheter (1) (3602) containing the expandable tissue stabilizer (3604), but is still internal to the catheter (2) (3606) containing the expandable cutter (3608) and the delivery catheter (3) (3610); but the delivery catheter is strong enough to contain the curvature without curvature of the entire delivery catheter. Upon distal deployment of the additional guide catheter, the device assembly generally bends in a direction pointing orthogonally toward the fossa ovalis. In some embodiments, during deployment of the cutter, the fully expanded lattice is substantially S-shaped or linear in side view.

[0119] In some embodiments, the cutter includes a stent pattern of various geometries, hi some embodiments, the lattice cells of the stent are comprised of a series of sine waves whose period gradually decreases as the stent expands along its length to form a sigmoid or S-shape in cross-section.

[0120] FIG. 39 shows an exemplary embodiment of a cutter described herein, which first makes a circumference of a perforation and then completes a forward movement of a full circumferential cut through the septum. Referring to FIG. 39, in some embodiments, the cutter first makes a circumference of a perforation (3901) and then transitions to complete a full circumferential cut (3903) through a distal or proximal movement of the cutter or a clockwise or counterclockwise rotation of the cutter, or a combination of both movements and rotations. In some embodiments, the blade makes a full cut from the initial contact. In some embodiments, after cutting, the blade body or the mouth of the blade serves as a storage to hold the resected tissue from the atrial septum and ensure tissue retrieval (this is a safety measure to provide protection against embolic events due to circulation of the resected tissue). In some embodiments, after cutting, the blade folds up with the resected tissue inside its body or mouth.

[0121] In some embodiments, after cutting, the body or distal opening of the cutter serves as a storage to hold the resected septum and securely retrieve tissue. Such tissue retention mechanism is a useful safety measure to provide protection against embolic events due to circulation of the resected tissue. In some embodiments, after cutting, the cutter is folded with the resected tissue within the body or distal opening of the blade. In some embodiments, when the stent is in its deployed state, the proximal edge does not expand and has 1-10 right angle cutouts arranged in a helical shape to encourage embedding of the unexpanded proximal edge of the blade or cutter into the blade catheter.

[0122] In some embodiments, the cutter comprises a stent with cells as shown in Figures 1 and 36. In some embodiments, the number of radially distributed lattice cells is between 3 and 30. In some embodiments, the number of radially distributed lattice cells is between 5 and 30, between 8 and 30, between 10 and 30, between 12 and 30, between 14 and 30, between 18 and 30, between 22 and 30, between 25 and 30, between 3 and 8, between 3 and 10, between 3 and 12, between 3 and 14, between 3 and 16, between 3 and 18, between 3 and 21, between 3 and 24, or between 3 and 27. In some embodiments, the number of lattice cells along its length, or along the proximal distal direction, is about 2 to 30, 5 to 30, 8 to 30, 10 to 30, 12 to 30, 14 to 30, 18 to 30, 22 to 30, 25 to 30, 3 to 8, 3 to 10, 3 to 12, 3 to 14, 3 to 16, 3 to 18, 3 to 21, 3 to 24, or 3 to 27. In some embodiments, the length of each point or tip of the cutter along the proximal distal direction is about 2 mm to about 3 cm, about 1.5 mm to about 2.5 mm, about 2.5 mm to about 3.5 mm, or about 2.2 mm to about 2.8 mm.

[0123] In some embodiments, the proximal edge of the cutter does not expand uniformly, or in some cases does not expand at all, when exposed to the exterior of the catheter that surrounds it. In some embodiments, the proximal edge or proximal portion, including the proximal edge of the cutter, includes a number of helical cutouts. Such helical cutouts (7101) encourage embedding of the unexpanded proximal edge of the stent blades into the catheter (e.g., catheter (2)) for accommodation of the cutter, as shown in FIG. 71. In some embodiments, the cutter is designed to additionally allow partial unsheathing (not shown) to allow creation of an opening having a diameter less than the maximum possible diameter of the cutter (when fully unsheathed).

[0124] In some embodiments, the cutter features radiopaque markers to orient its position within the body, its relationship to other system components, and its current state (expanded or folded); additional radiopaque markers are added to other elements to provide visualization of their relative positions with respect to one another under fluoroscopic guidance.

[0125] In some embodiments (not shown), the distal portion of the cutter is one continuous blade (as opposed to multiple blades), optionally in the shape of a saw.

[0126] In some embodiments, the cutter is constructed of a balloon expandable non-shape memory alloy (e.g.: stainless steel as opposed to a self-expanding shape memory alloy as described elsewhere herein). This embodiment allows for gradual, controlled, cutter-free expansion and collapse. In some embodiments, the cutter includes an expandable balloon element within the proximal inner diameter of the cutter that can be controllably expanded to a controlled diameter and monitored radiographically while still providing sufficient incisor exposure to penetrate the atrial septum and capture the resected tissue. In this configuration, the proximal portion of the cutter is rarely fully unsheathed to allow for easier resheathing of the cutter through either proximal movement of catheter (2) into catheter (3) or distal movement of catheter (3) through catheter (2).

[0127] FIG. 21 is a representative illustration of an exemplary embodiment of an expandable cutter, where the distal edge of the cutter has many (e.g., eight) serrations / teeth and forms a polygonal (e.g., octagonal) cross-section opening. The cutter blades are deployed by expansion of radially distributed struts, where the accordion spring shaped blades act as scissors with a sharpened end. The blades are connected by a hinge at the proximal edge of the blade. The struts are connected to a proximal hinge that allows the blades to fold and expand. The distal edges of the blades are connected via springs that ensure that when the blades are expanded by the struts, they remain under tension and the tips meet.

[0128] Figure 22 is a representative illustration of the blade detail shown in Figure 21 with a close-up (circled) showing the two cutting edges on each tooth / serration of the cutter in an extended state and the tip detail at the distal end of the blade connected by a spring, allowing the blades to rotate in the same plane and meet with a penetrating sharp tip.

[0129] In some embodiments, as illustrated in Figures 21 and 22, the blades (2101), (2201) or cutting ends (2100), (2200) of the cutters are deployed from the delivery catheter (3) through the expansion of radially divergent struts (2107) attached to the catheter (2) (2106). In this configuration, the proximal portion of the cutter is typically fully unsheathed upon passing through the septum to allow clearance of the cutter (2108), (2208) and clear the diameter of the tissue stabilizer (2104) deployed from the catheter (1) (2102), and then retracted back into the catheter (2) and catheters (3) (2106), (2110). The struts, in some embodiments, preferably comprise a shape memory material; however, the blades may be fabricated from either a shape memory alloy or a non-shape memory alloy. Hinges 2112, 2212 connect to the proximal ends of the blades and allow the accordion springs to open when the struts 2107 are unsheathed. Springs 2214 connect to the distal ends of the blades 2101, 2201 and allow the tips of the blades to touch when fully extended.

[0130] FIG. 23 is a representative illustration of an exemplary embodiment of the cutter in an expanded state, where the cutter blades are deployed to show a modified cutting pattern requiring only one cutting edge on each tooth / serration of the cutter. In this embodiment, as illustrated in FIGS. 21 and 22, at least one end of each edge (2101), (2201) of each tooth features a sharpened surface or cutting edge, and the blades are alternately sharpened on the inside and outside of the blades, creating a scissors effect. Each hinge connects the internally and externally sharpened blades. This configuration is suitable for both plunge grinding and rotary grinding in either direction.

[0131] FIG. 24A is a representative illustration of an embodiment, illustrating cutter teeth formed into a series of waves that converge to a narrow point. FIG. 24B is a representative illustration of an embodiment, illustrating cutter teeth formed into a series of "U" shapes to create a crowned appearance with sharp edges. In some embodiments of cutter (2300), only one edge (2301) of each tooth (2308) is sharpened, as illustrated in FIG. 23. In the aforementioned embodiment, the non-sharp edge of each tooth (2302) is approximately perpendicular to the tissue during penetration. In some embodiments, an alternative cutter has a single continuous cutting blade with one cutting edge.

[0132] In some embodiments, the cutter teeth are formed in a series of "U" shapes to create a crown-like profile with pointed edges, as illustrated in Figures 24A and 24B. In some embodiments, the cutter teeth are formed in a series of wavy shapes (2401) that come to a narrow point.

[0133] In some embodiments, the cutter penetrates the septum and either plunges or rotates before, during, or after penetration to create a complete circumferential or O-shaped cut.

[0134] In some embodiments, the cutter takes the form of one or more blades that pierce the septum with a reciprocating rotary cutting or plunging motion, hi some embodiments, the cutter takes the form of two or more blades that pierce the septum with a reciprocating rotary cutting or plunging motion.

[0135] In some embodiments, the cutter takes the form of one or more blades that pierce the septum with a vibration. In some embodiments, the cutter takes the form of two or more blades that pierce the septum with a vibration. In some embodiments, the vibration is generated mechanically, electrically, hydraulically, pneumatically, magnetically, or sonically.

[0136] In some embodiments, the device assemblies disclosed herein include optional mechanisms at or about the proximal end of the device assembly configured to provide alternative actuation and movement of the cutter. In some embodiments, such alternative actuation mechanisms include handles; knobs; hydraulic connections; pneumatic connections; electric motor connections; or sonic, ultrasonic, or otherwise vibratory connections. In some embodiments, the alternative actuation and movement includes rotary and reversible movements.

[0137] In any of these supplemental motion methods, one skilled in the art will recognize that in some embodiments, plunging, rocking, rotating, and oscillating motions incorporated into the deployment or actuation of the cutter reduce the force required to translate the cutting blade through tissue. In any of these supplemental motion methods, one skilled in the art will recognize that such plunging, rocking, rotating, and oscillating motions incorporated into the deployment or actuation of the cutter reduce the force required to translate the cutting blade through tissue.

[0138] In any of the above embodiments and examples, the shape of the anastomosis created by the cutting blades is optionally different from a circle. Rather, to create a shunt structure with improved patency, the shape of the anastomosis can be configured to have shapes generally including: a circle; a square; a rectangle; a triangle; an oval; a polygon; or any other feasible geometric shape.

[0139] In some embodiments, the expansion dimension of the tissue stabilizer is less than the expansion dimension of the cutter. In some embodiments, the expansion dimension of the cutter is about 1% to about 50% greater than the expansion dimension of the tissue stabilizer (in a range of 1% to 65%). In some embodiments, the expansion dimension of the cutter is about 0.1% to about 10% greater than the expansion dimension of the tissue stabilizer. In some embodiments, the expansion dimension of the cutter is about 0.1% to about 20% greater than the expansion dimension of the tissue stabilizer. In some embodiments, the expansion dimension of the cutter is about 0.1% to about 25% greater than the expansion dimension of the tissue stabilizer. In some embodiments, the expansion dimension of the cutter is about 1% to about 15% greater than the expansion dimension of the tissue stabilizer. In some embodiments, the expansion dimension of the cutter is about 1% to about 20% greater than the expansion dimension of the tissue stabilizer. In some embodiments, the expansion dimension of the cutter is about 1% to about 35% greater than the expansion dimension of the tissue stabilizer.

[0140] Those skilled in the art will appreciate that in some embodiments, the direction of cutting may be reversed, from the left atrium to the right atrium, with appropriate mechanics of device assembly.

[0141] For example, Figure 25A is a sequential representative illustration of an exemplary embodiment of a reverse cutting action, where a cutter is attached to a catheter (1) (remaining in the right atrium) and a tissue stabilizing element is attached to a catheter (2) and slidably engaged with the lumen of catheter (3). Cutter 3 is then advanced through the septum until the cutter is disposed distal to the septum and the pulling element is disposed proximal to the septum. For example, Figure 25B is a sequential representative illustration of an exemplary embodiment of a reverse cutting action, where a cutter is attached to a catheter (1) (remaining in the right atrium) and a tissue stabilizing element is attached to a catheter (2) and slidably engaged with the lumen of catheter (3). Cutter 3 is then advanced through the septum until the cutter is disposed distal to the septum and the pulling element is disposed proximal to the septum. For example, Figure 25C is a sequential representative illustration of an exemplary embodiment of a reverse cutting action, where a cutter is attached to catheter (1) (remaining in the right atrium) and a tissue stabilizing element is attached to catheter (2) and slidably engaged with the lumen of catheter (3). Cutter (3) is then advanced through the septum until the cutter is disposed distal to the septum and the pulling element is disposed proximal to the septum. For example, Figure 25D is a sequential representative illustration of an exemplary embodiment of a reverse cutting action, where a cutter is attached to catheter (1) (remaining in the right atrium) and a tissue stabilizing element is attached to catheter (2) and slidably engaged with the lumen of catheter (3). Cutter (3) is then advanced through the septum until the cutter is disposed distal to the septum and the pulling element is disposed proximal to the septum.

[0142] As illustrated in Figures 25A-25D, in some embodiments, the device assembly (2500) includes a guidewire (2501) that penetrates the atrial septum and provides a guideway for the device assembly. However, a cutter (2508) is attached to a catheter (1) (2502), which has a larger diameter at its distal end and a smaller diameter at its proximal side where it slidably engages catheter (2), and a tissue stabilizing element, or equivalent tissue pulling element (2504), is attached to catheter (2) (2506). In this configuration, both the cutter and tissue stabilizing element are made of a shape memory material and are housed in their folded state within the delivery catheter (3) (2510). The cutter (3) is then advanced through the septum until the cutter (2508) is positioned proximal to the septum and the tissue stabilizing element, or equivalent tissue pulling element, is positioned distal to the septum. Once the cutter and tissue stabilizing element are in place relative to the septum, catheter (3) is pulled back proximally to expose catheter (1) (2502), thereby allowing expansion of the cutter distal to the septum, and to expose catheter (2) (2506), thereby allowing expansion of the tissue stabilizing element or equivalent tissue pulling element proximal to the septum. In some embodiments, catheters (1) and (2) are then translated relative to one another to cut through the atrial septum. In this embodiment, the cutter is small compared to the pulling element such that the cutter is housed within the tissue stabilizing element after cutting. In some embodiments, catheter (3) (2510) is then advanced distally relative to catheters (2) (2506) and (1) (2502), thereby simultaneously collapsing both the pulling element (2504) and cutter (2508). In some embodiments, the area encompassed circumferentially or in cross section by cutter (2508) is less than the area encompassed circumferentially or in cross section by stabilizing element (2504).

[0143] FIG. 26A is a representative illustration of an embodiment of a cutter in a partially extended / partially deployed state using an "umbrella" mechanism. FIG. 26B is a representative illustration of FIG. 26A in a fully deployed / expanded state. Thus, in some embodiments, such as (2600) illustrated in FIGS. 26A and 26B, the cutter (2608) is expanded outside of the delivery catheter (3) using an "umbrella" strut mechanism (2618). A rigid strut (2618) couples a movable slider (2620) to the cutter (2608) such that movement of the slider through the catheter (4) (2616) associated with the cutter rotates the strut outward, but not more than 90 degrees, expanding the diameter of the cutter (2608). The containment catheter (1) (2602), including the inner catheter (4) (2616) and further the tissue stabilizer (2604), is deployable from within the catheter (3), which is slidably engaged within the catheter (4). The catheter (2) allows the slider to move distally toward the tip of the catheter (4), and prohibits a strut connected to the slider from rotating outward more than 90 degrees. In a similar embodiment, movement of the slider (2620) and expansion of the cutter is triggered by a spring, and is undeployed by proximal movement of the cutter. In some embodiments, a rigid strut connects the movable catheter (4) (2616) and the cutter (2608) such that movement of the catheter (4) relative to the cutter rotates the strut upward, but not more than 90 degrees, resulting in an expansion of the diameter of the cutter. Figures 26A and 26B also show the catheter (2) (2606) and the umbrella handle or slider (2620) that supports the support pole.

[0144] In some embodiments, such as the one illustrated in Figures 27A and 27B (2700), the catheter (2) (2706) is coupled to a coaxial alignment mechanism having a spring mechanism (2722) housed in its distal tip. On the other side of the spring is a coaxially aligned plunger (2724) that extends out beyond the plane in which the deployed cutter rests. The catheter (1) (2702) passes through the spring mechanism, and its tissue stabilization mechanism (2704) is deployed on the left atrial side of the septum. When actuating the cutter (2708) toward the septum, the plunger is forced to compress first such that upon completion of the cut, the spring pushes the resected tissue against the cutter. Figures 27A and 27B also show the delivery catheter (3) (2710), tissue stabilizer (2704), and septum (2720). Figure 27A is a representative illustration of an embodiment of the cutter in a partially extended / partially deployed state, where the catheter (2) is coupled to a coaxial alignment mechanism with a spring mechanism housed in its distal tip, and Figure 27B is a representative illustration of the deployed spring-plunger mechanism of Figure 27A, where the spring pushes the resected tissue distally towards the cutter.

[0145] In some embodiments, treatment is applied to the tissue shear incision during or after tissue destruction for the purpose of promoting scar formation or fibrosis and preserving opening patency. This treatment in some embodiments takes the form of electrocautery, radiofrequency ablation, cryoablation, pharmacological injections, expansion of pharmacologically coated balloons, or placement of radial sutures to create a tissue scaly overlay. In some embodiments, patency is also achieved by an implant device assembly made of a bioabsorbable material, with the stent holding the opening open for a defined period of time prior to its resorption.

[0146] In some embodiments, in any one of the cutter embodiments described, the cutter can be configured with a thermocouple wire near the tip of the cutter that aids in tissue cutting by cauterizing the tissue as it is cut. The thermocouple wire is heated by passing an electric current through the metal thermocouple wire. Additionally, this will help maintain long-term shunt patency.

[0147] In some embodiments, the cutter includes a support or scaffold and features at least one bladed edge at its distal tip. In some embodiments, the cutter is delivered to the atrial septum and upon deployment and actuation, cuts a portion of the atrial septum creating an opening. The bladed edge, in some embodiments, assumes a form factor that reduces the amount of force required to propel the cutter through the septum. In some embodiments, the cutting dimension of the cutting element or cutter is the dimension of the cutter in an expanded state. In some embodiments, the cutting dimension of the cutter is the dimension of the expanded cutter at its distal end that touches and cuts tissue. In some embodiments, the cutting dimension is the dimension of the tissue cut by the cutter.

[0148] In some embodiments, the expandable cutter expands via relative motion between the delivery catheter and the cutter of the device assembly. In some embodiments, the cutter is expanded by moving the cutter out of the delivery catheter and optionally towards the septum, while the delivery catheter remains stationary relative to the septum. In some embodiments, the cutter is expanded by moving the delivery catheter away from the septum, while the cutter remains stationary relative to the septum during expansion. In some embodiments, the cutter is moved towards the septum after expansion. In some embodiments, the cutter and delivery catheter are moved together, such that neither remains stationary relative to the septum, while the final movement of both is for the cutter to exit the distal end of the delivery catheter and expand.

[0149] In some embodiments, the fully expanded cutter engages or passes through the left atrial side of the atrial septum, such that the cutter completely penetrates and cuts the atrial septum, optionally removing the cut tissue, thereby creating an interatrial pressure relief opening in the atrial septum. In some embodiments, the tissue cut by the cutter is at least a portion of the atrial septum. In some embodiments, the tissue cut by the cutter is only a portion of the septum. In some embodiments, the interatrial pressure relief opening is made large enough to allow blood flow from the left atrium to the right atrium through the interatrial pressure relief opening such that no more than 50% of the blood in the left atrium is shunted to the right atrium. In some embodiments, the interatrial pressure relief opening is made large and / or sized large enough to slow the natural healing process of the tissue to preserve the patency of the interatrial pressure relief opening in the atrial septum without implanting a stent, valve, or any other mechanical implant therein.

[0150] In some embodiments, when the distal end of the delivery catheter is retracted proximally, the expandable cutter is exposed and expands from a collapsed size to an expanded shape of adjustable size and coaxial with the first inner coaxial catheter. In some embodiments, the adjustable size of the expandable cutter is controllable by the amount of proximal retraction of the delivery catheter. In some embodiments, the expandable cutter includes an expandable lattice, and the distal end of the expandable cutter lattice includes a sharp end configured to operate as a tissue-cutting blade. In some embodiments, the multiple sharp ends configured to operate as tissue-cutting blades include a tissue-piercing end and one or more side edges having a sharp knife-like edge.

[0151] A tissue retention mechanism is defined herein as any component, or combination of components, of the device assembly that is configurable to capture resected tissue from the atrial septum.

[0152] In some embodiments, the multiple sharp edges resemble wavy or straight teeth, where the tips are either pointed or rounded or a combination thereof, and the roots are either pointed or rounded or a combination thereof. In some embodiments, the expandable cutter includes a continuous blade including a shape memory alloy, and the distal end of the continuous blade includes: a single smooth sharp knife blade configured to operate as a full circumferential (continuous) tissue-cutting blade; or multiple sharp serrations or teeth along the continuous blade. In some embodiments, a single smooth sharp knife blade or multiple sharp serrations along the continuous blade are configured to operate as a tissue-cutting blade. In some embodiments, the delivery catheter is at least partially retracted distally to expose the cutter so that it expands, and the third cutter is translated distally such that the sliding element slidably engages within the cutter, engaging two or more struts and radially increasing the size of the cutter such that its size is greater than the size of the stabilization element.

[0153] In some embodiments, the excised portion of tissue (pierced by catheter (1)) is secured and removed from the body. In some embodiments, a tissue retaining element prevents the excised tissue from inadvertently separating from the catheter (1) and allows for the transfer of the excised tissue into the delivery catheter (3) prior to removal of the device assembly from the body.

[0154] In some embodiments, the tissue retention mechanism includes a tissue stabilizer or a pulling element, or the like. In some embodiments, the tissue retention mechanism includes a hooked end of the guidewire. In some embodiments, the tissue retention mechanism includes a space along the length of the first catheter between the cutter and the tissue stabilizer. In some embodiments, the tissue retention mechanism includes a cutting mechanism in combination with the first catheter. In some embodiments, the tissue retention mechanism includes a cutting mechanism in combination with the first catheter and the tissue stabilizer. In some embodiments, the tissue retention mechanism includes only a cutting mechanism, where the cutting mechanism folds over the resected tissue and captures it within the cutting mechanism as it is pulled back into the delivery catheter.

[0155] In some embodiments, the first inner coaxial catheter further comprises an expandable balloon for controllably expanding the expandable cutter, where the dimensions of the cutter are controlled by expansion of the expandable balloon, optionally disposed within a central portion of the cutter. In some embodiments, the first inner coaxial catheter further comprises an expandable strut configured to controllably engage an inner dimension of the expandable cutter, where the dimensions of the cutter are controlled by expansion of the expandable strut, optionally disposed within a central portion of the cutter.

[0156] In some embodiments, the delivery catheter disclosed herein includes a unidirectional or bidirectional steerable sheath. In some embodiments, the delivery catheter is a deflectable catheter. In some embodiments, the delivery catheter is a wire-reinforced or braided catheter. In some embodiments, the delivery catheter is a reference catheter. In some embodiments, the delivery catheter includes a metal, alloy, polymer, plastic, biomaterial, or combinations thereof. In some embodiments, the delivery catheter includes a reinforced distal tip. In some embodiments, such a reinforced distal tip provides radial stiffness and allows for unsheathing and sheathing of the cutter. In some embodiments, the delivery catheter includes one or more metals, alloys, or meshes for reinforcement. In some embodiments, the delivery catheter has a bend radius of about 0.5 to about 4 inches, about 0.4 inches to 4.5 inches, about 0.5 to about 1.5 inches, about 0.5 to about 2 inches, about 1 inch to about 2 inches, about 1 inch to about 3 inches, about 1.5 inches to about 3.5 inches, about 2 inches to about 3 inches, about 2.5 inches to about 4 inches, about 3 inches to about 4 inches, or about 3 inches to about 4.5 inches. In some embodiments, the delivery catheter is the main housing catheter for the remainder of the device assembly. The blade or cutter catheter is housed in the distal portion of the delivery catheter which keeps the blade compressed until it is ready for deployment. Additionally, it allows for packing of the excised tissue inside.

[0157] In some embodiments, the delivery catheter may be constructed of a combination of polymer, metal, or braided or wound reinforcement using metal, polymer, or combinations thereof to allow sufficient pushability during introduction of the entire device assembly. The delivery catheter may have a round window to allow for rapid wire exchange during its introduction into the body. The delivery catheter may include one or more radiopaque markers to aid in its proper delivery to the atrial septum. In some embodiments, the delivery catheter is a unidirectional or bidirectional steerable or deflectable sheath that can support and maintain its degree of deflection during the cutting operation. In some embodiments, the delivery catheter has a preformed curve oriented toward the atrial septum while having a rod that is stiff enough to straighten and remove from its internal lumen. In some embodiments, the distal edge of the delivery catheter is reinforced with a stiff metal, polymer, or combinations thereof, or a shape memory alloy, polymer, or combinations thereof to allow easier unsheathing, sheathing, or both unsheathing and sheathing of the stent blades. In some embodiments, the distal edge of the delivery catheter is reinforced with additional radial stiffness to allow easier unsheathing, sheathing, or both unsheathing and sheathing of the stent blades.

[0158] In some embodiments, the delivery catheter ranges in size from 8 to 18 Fr. In some embodiments, the delivery catheter comprises a material that is sufficiently rigid to straighten the shaft of a second catheter while in the delivery catheter, and the other catheter is free to move therein. In some embodiments, the delivery catheter is sufficiently rigid to straighten components housed therein while in the delivery catheter, but also allows free sliding or movement therein.

[0159] In some embodiments, the guide catheter defines the path taken by the cutter from the port of the delivery catheter to the septum and ensures and aids in coaxial alignment during cutting of the septum. In some embodiments, the coaxial alignment mechanism provides centralization between the cutter and the tissue stabilizer and tissue holding elements. In some embodiments, the coaxial aligner reduces the risk of inadvertent interaction between the cutter and the tissue stabilizer. The coaxial aligner also serves as a means to ensure that the cutter (coupled to the catheter (2)) is advanced centrally through the tissue stabilizer and through the septum.

[0160] In some embodiments, the guide catheter (3803) houses the guidewire (3801) therein as shown in FIG. 38A-D. In some embodiments, the guide catheters disclosed herein include a steerable sheath, which may be one-way or two-way. In some embodiments, the guide catheter is a deflectable catheter. In some embodiments, the guide catheter is a wire-reinforced or braided catheter. FIG. 38A-D also shows a shape memory alloy mesh catheter (3804). FIG. 38A-D shows an exemplary sequential embodiment of the device assembly described herein, where the guide catheter has a smaller OD at the distal end to ensure it passes through the atrial septum while traveling over the guidewire, thus eliminating the need for an additional mesh-housed catheter to deploy the tissue stabilization element.

[0161] In some embodiments, as shown in FIG. 37, for example, the guide catheter (3703) has a preformed curve that is oriented toward the atrial septum (3716) as it advances past the tip of the delivery catheter (3) (3710) or the cutter (3708). In some embodiments, the guide catheter translates through the shape memory alloy mesh containing catheter once the balloon or shape memory alloy mesh plug expands to secure the system to the septum. Additionally, the guide catheter is stiff enough to resist deflection when the blade catheter translates through it or during cutting of the septum. FIG. 37 is an exemplary embodiment of a device assembly disclosed herein with a guide catheter having a predefined curve.

[0162] In some embodiments, the guide catheter is constructed from any combination of polymer, metal, metal or polymer-based braided or wound reinforcements. In some embodiments, the guide catheter may have a round window to allow for rapid wire exchange during its introduction into the body. In some embodiments, the guide catheter may include one or more radiopaque markers to aid in its proper delivery to the atrial septum. In some embodiments, the guide catheter is a unidirectional or bidirectional steerable or deflectable sheath that can support and maintain its degree of deflection during the cutting operation. In some embodiments, the metallic catheter has a smaller diameter softer tip (as in FIG. 38A-D) that eliminates the need for an additional shape memory alloy mesh-containing catheter to deploy the tissue stabilization element (3804). In some embodiments, the guide catheter has a narrow tip at its distal edge to ensure coaxial alignment with the shape memory alloy mesh catheter. In some embodiments, the guide catheter has a tissue stabilizer coupled to and incorporated into its distal tip; such that once the distal tip of the guide catheter is inserted into the left atrium and the tissue stabilizer is actuated past the tip of the guide catheter, the tissue stabilizer is deployed, anchoring the system to the atrium and providing stabilization of the tissue during tissue cutting.

[0163] In some embodiments, the guide catheter has an appropriate stiffness to allow adjustment of its orientation to the septum to guide other portions of the device assembly, such as the cutter and tissue stabilizer. In some embodiments, the guide catheter is a reference catheter. In some embodiments, the guide catheter comprises a metal, an alloy, a polymer, or a combination thereof.

[0164] In some embodiments, the guide catheters (4103), (4203), (4303), (4403) acquire a preformed curve upon leaving the delivery catheter. In some embodiments, the preformed curve is formed, at least in part, automatically in the guide catheter upon leaving the delivery catheter. In some embodiments, the preformed curve is formed by an additional trigger upon leaving the delivery catheter. In some embodiments, the preformed curve is towards and up to the atrial septum. In some embodiments, the preformed curve is towards or up to the atrial septum. In some embodiments, the curve is not preformed, but is formed by an additional manipulation or action. In some embodiments, as shown in Figs. 38, 41A-E, 42A-E, 43A-E, and 44A-E, the guide catheter translates the tissue stabilizer delivery catheter, or the proximal portion of the tissue stabilizer, over the guidewire (4101), (4201), (4301), (4401) while optionally advancing over the tip of the delivery catheter or other housing encasing the guide catheter, while the tissue stabilizer is deployed to secure the remaining portions of the device assembly to the septum. In some embodiments, the guide catheter is withdrawn after being successfully advanced to deliver one or more portions to a desired location in the heart. In some embodiments, the guidewire is withdrawn before or after cutting the atrial septum. In some embodiments, the guide catheter is sufficiently stiff so as not to deflect when the catheter (2) or the catheter encasing the cutter is translated therethrough or during cutting of the atrial septum. Figures 41AE, 42AE, 43A-E, and 44A-E also show shape memory alloy mesh containing catheters (4102), (4202), (4302), (4402), and shape memory alloy mesh catheters (4104), (4204), (4304), and (4404).

[0165] 38A-38D, in some embodiments, the guide catheters disclosed herein are metallic catheters with smaller diameter softer tips (e.g., polymer tips). In some embodiments, such guide catheters eliminate the need for an additional shape memory alloy mesh-containing catheter, and the shape memory alloy mesh plug or tissue stabilizer is contained directly within the guide catheter.

[0166] In some embodiments, the shape memory alloy mesh catheter, or the catheter housing the tissue stabilizer, is delivered over a guidewire, hi some embodiments, the shape memory alloy mesh catheter features an internal lumen that allows the guidewire to properly fit therethrough.

[0167] In some embodiments, the catheter (2) or the catheter for encasing the cutter is a wire-reinforced or braided catheter. In some embodiments, the catheter (2) or the catheter for encasing the cutter (delivery catheter) includes one or more shape memory materials, such as shape memory alloys. Referring to FIG. 40, in some embodiments, the catheter (2) (4006) features a smaller internal lumen at its distal end to ensure coaxial alignment with the catheter housed therein (the guide catheter, the shape memory alloy mesh-encased catheter (4002), or both). In some embodiments, the distal tip of the guide catheter is of smaller diameter and includes a flexible portion (4004) that is used to pass through the septum and place the shape memory alloy mesh tissue stabilizer into the left atrium, eliminating the need for an additional shape memory alloy mesh-encased catheter. FIG. 40 shows an exemplary embodiment of a blade / cutter catheter disclosed herein, which optionally has a smaller internal lumen at its distal end to ensure coaxial alignment with the balloon catheter or the shape memory alloy mesh-encased catheter.

[0168] 35A and 35B, in some embodiments, the distal tip of the guide catheter (5303) has a smaller diameter to ensure a coaxial arrangement (B in FIG. 53) and has a more flexible portion (5312) that is used to pass through the septum (5320) and introduce the shape memory alloy mesh tissue stabilizer (5304) into the left atrium, thereby eliminating the need for an additional shape memory alloy mesh-containing catheter to deploy the shape memory alloy mesh; and the guide catheter (5303) has a flexible portion before or after the curve to assist in safe stability of the system during cutting, as shown in A in FIG. 53. AB in FIG. 53 shows an exemplary embodiment of the device assembly disclosed herein, where the distal tip of the guide catheter has a smaller diameter and a more flexible portion that is used to pass through the septum and introduce the shape memory alloy mesh tissue stabilizer into the left atrium. The other elements of the device assembly, cutter (5308), cutter catheter (2) (5306), delivery catheter (3) (5310), are advanced into the right atrium before the distal tip of the guide catheter passes through the septum. In some embodiments, the balloon catheter or catheter (1) includes a shape memory alloy mesh. In some embodiments, the shape memory alloy mesh is expandable and includes a collapsed state and an expanded state. In some embodiments, the shape memory alloy mesh has one or more radiopaque markers thereon for imaging the tissue stabilizer or to guide the procedure using these markers. In some embodiments, the shape memory alloy mesh has one or more radiopaque markers thereon for imaging the tissue stabilizer and to guide the procedure using these markers.

[0169] In some embodiments, the assembly disclosed herein includes a shape memory alloy mesh catheter, a shape memory alloy mesh containing catheter, or both. In some embodiments, the shape memory alloy mesh catheter includes one or more structures similar to a disk, plug, valve, etc. In some embodiments, one or more disks of the shape memory alloy mesh catheter are sized relative to the blade size to encase the tissue and plug the distal end of the delivery catheter. In some embodiments, the guide catheter or guide wire includes a steerable metal, alloy, or polymer. Such a steerable guide wire, in some embodiments, allows for slight adjustments during orientation to the atrial septum. In some embodiments, the device assembly described herein includes a septal crossing needle. In some embodiments, the distal end of the needle includes a plastic or polymeric material.

[0170] In some embodiments, the shape memory alloy mesh catheter features a dog bone mesh. In some embodiments, the shape memory alloy mesh catheter features one or more disks, valves, or plugs having a dog bone shape, either alone or in combination with other disks, valves, plugs, or combinations thereof. In some embodiments, the shape memory alloy mesh catheter is held perpendicular to at least a portion of the septum during at least a portion of the procedure. In some embodiments, one or more disks, valves, or plugs of the shape memory alloy mesh catheter are held perpendicular to at least a portion of the septum before, during, or after the septum is sandwiched therebetween. In some embodiments, the guidewire or its distal tip is held perpendicular to at least a portion of the septum during or after its entry into the left atrium. In some embodiments, the shape memory alloy mesh catheter, or one or more disks, valves, plugs, or combinations thereof, includes a guard to protect it from inadvertent puncture or other damage by other parts of the assembly. In some embodiments, the shape memory alloy mesh catheter, or one or more disks, valves, plugs, or combinations thereof, has a rigidity that reliably protects it from inadvertent puncture or inadvertent retraction of the disk, valve, plug, or combinations thereof through the initial puncture site in the atrial septum or other lesion by other parts of the assembly.

[0171] In some embodiments, the cutter catheter may be constructed from any combination of braided or wrapped reinforcements of metal, polymer, or both to allow sufficient pushability during tissue cutting and during folding or unfolding of the blade when unsheathing the blade. In some embodiments, the blade catheter may have a round window to allow for rapid wire exchange during its introduction into the body. In some embodiments, the blade catheter may include one or more radiopaque markers to aid in its proper delivery to the atrial septum. In some embodiments, the blade catheter is a unidirectional or bidirectional steerable or deflectable sheath that can support and maintain its degree of deflection during the cutting operation. In some embodiments, the blade catheter has a preformed curve that is oriented toward the atrial septum as it advances beyond the tip of the delivery catheter. In some embodiments, the blade catheter is translated onto the shape memory alloy mesh receiving catheter once the tissue stabilization element is positioned to secure the system to the septum. Additionally, the blade catheter is sufficiently stiff to prevent deflection as the blade catheter is translated through the septum. In some embodiments, the braided catheter has a smaller internal lumen so that its ID is level with the OD of the catheter therein (which serves as a guide or means of pulling tissue at its distal end to ensure coaxial alignment with the catheter therein).

[0172] In some embodiments, the outer diameter of the distal portion of catheter (1) defines, constrains, or limits the inner diameter and distal portion of catheter (2) such that catheter (1) completely occupies the inner lumen of catheter (2) (distal portion). This ensures coaxial alignment between the tissue stabilizer and cutter (and therefore catheters (1) and (2) respectively). In some embodiments, coaxial alignment is also achieved through a separate centering component that occupies the space between catheter (1) and catheter (2) (distal portion). Coaxial alignment is also achieved in some embodiments by measuring the distal portion of catheter (1) to occupy the entire lumen of catheter (2). In some embodiments, the delivery catheter includes a central lumen that houses all other components of the assembly within it when the assembly is not sheathed or deployed prior to use.

[0173] In some embodiments, the delivery catheter (catheter (3)) features radiopaque markers to aid in orientation and positioning within the right atrium and to allow visualization in relation to other system components (e.g., confirmation of sheathed or unsheathed status of the cutting blade).

[0174] Additionally, any of the embodiments described herein can be adapted to store and retrieve steerability using mechanical means or robotic catheter systems. In some embodiments, a prefabricated steerable catheter is used through the delivery catheter of the device assembly.

[0175] Additionally, any of the embodiments described herein can be adapted to allow for retrograde cutting and ablation of the septum from the left atrium to the right atrium, such that the tissue stabilization element is deployed in the right atrium and the cutter is deployed in the delivered left atrium.

[0176] In some embodiments, as illustrated in FIG. 28A, catheter (2) (2806) inside steerable delivery catheter (3) (2810) has a predetermined curvature so that upon exiting steerable delivery catheter (3), catheter (2) is configured to orthogonalize the entire device assembly to the fossa ovalis of the atrial septum (2820). In some embodiments, steerable delivery catheter (3) is stiff enough to straighten catheters (1) and (2) while still within the steerable delivery catheter and while catheters (1) and (2) are still free to translate through catheter (3). In some embodiments, the curvature on catheter (2) is steerable through a series of cables. In some embodiments, the off-the-shelf or one-piece steerable catheter provides limited orientation of the transcatheter device into the atrial septum, but the internal catheter is configurable to fine-tune the aim of the cutter to orthogonalize the fossa ovalis of the atrial septum. In some embodiments, as illustrated in FIG. 28B, an additional catheter (4) is introduced and resides within the delivery catheter and slidably engages with the outer diameter of the catheter (2) and is steerable, eliminating the need for the delivery catheter (3) to be steerable. FIG. 28A is a representative illustration of an embodiment of the assembly, where the inner catheter (2) (the catheter containing the expandable cutter) has a predetermined but flexible bend in one of the inner catheters inside the delivery catheter; but the delivery catheter is strong enough to include the bend without bending the entire delivery catheter. FIG. 28B is a representative illustration of an embodiment of the assembly of FIG. 28A, where the additional inner catheter has a predetermined but flexible bend and is external to the inner catheter but still inside the delivery catheter; but the delivery catheter is strong enough to include the bend without bending the entire delivery catheter. Upon distal deployment of the additional inner catheter, the device bends in a generally orthogonal direction to point toward the fossa ovalis.

[0177] Additionally, the inventors recognize the ability to combine one or more embodiments of the device assembly described herein with an atrial shunt device (ASD) (2900) as a system with an automated auscultation device for long-term non-invasive monitoring of flow or pressure through or across the created shunt.

[0178] The creation of the ASD adds a third heart sound, which in some embodiments is non-invasively monitored by auscultation via a digital microphone on a device intended to go home with the patient after the creation of the ASD. A change in the third heart sound, which is pre-calibrated to the patient, would indicate a change in the shunt mechanics. The creation of the shunt combined with auscultatory monitoring would allow for monitoring the flow through the shunt to monitor early signs of excess flow, which may cause right heart failure, or insufficient flow, which may be a sign of inadequate shunting, and this combination would allow for early changes in the management of the patient.

[0179] In some embodiments, the process of using the device assemblies disclosed herein includes one or more of the following steps. Some of these steps must be performed in a specific order, while some are performed out of order as alternative process configurations. One embodiment of the order of steps is provided below, but the steps may be rearranged.

[0180] Process Step 1: Vascular access is achieved via the femoral vein using standard placement techniques (Seldinger technique).

[0181] Process Step 2: A transseptal puncture through the fossa ovalis (200) of the atrial septum is performed using standard placement techniques, leaving the guidewire (201) in place (illustrated in FIG. 2). FIG. 2 is an illustration of an exemplary embodiment of a transseptal puncture through the fossa ovalis. FIG. 2 also shows a tissue stabilizer (204).

[0182] Process Step 3: A tissue stabilizer (eg: balloon catheter) is advanced over the transseptal guidewire and across the septum.

[0183] Process step 4: The tissue stabilization element (304) is deployed to provide tension to the septum when pulled proximally or when held stationary against the advancement of the cutter (illustrated in FIG. 3). FIG. 3 is an illustration of an exemplary embodiment of a balloon catheter with a balloon inflated in the left atrium. FIG. 3 also shows the guidewire (301), the fossa ovalis (300), and the catheter (1) (302).

[0184] Process step 5: A cutter (a self-expanding shape-memory stent with a sharp blade on its distal end) is delivered (sheathed) into the right atrium.

[0185] Process step 6: The cutter (408) is unsheathed (partially or completely) in the right atrium by pulling back on the delivery catheter or by pushing the catheter with the cutter attached forward (FIGS. 4A and 4B). FIG. 4A is an illustration of an exemplary embodiment of a cutter in which a self-expanding shape memory stent with a sharp blade on its distal end has been delivered (and partially or completely unsheathed) into the right atrium. FIG. 4B is an illustration of an exemplary embodiment of a cutter in which a self-expanding shape memory stent with a sharp blade on its distal end has been delivered (and partially or completely unsheathed) into the right atrium with a coaxial aligner. FIGs. 4A and 4B also show the guidewire (401), fossa ovalis (400), and catheter (1) (402), tissue stabilizer (404), catheter (2) (406), and coaxial aligner (412).

[0186] Process step 7: The cutter (508) translates forward to penetrate and cut the septum while the tissue stabilizer (balloon) applies counter tension (FIGS. 5A and 5B). FIG. 5A is an illustration of an exemplary embodiment of a cutter translating forward to penetrate and cut the atrial septum while the tissue stabilizer (balloon) applies counter tension on the opposing surface. FIG. 5B is an illustration of an exemplary embodiment of a cutter with a coaxial aligner translating forward to penetrate and cut the atrial septum while the tissue stabilizer (balloon) applies counter tension on the opposing surface. FIGS. 5A and 5B also show the guidewire (501), fossa ovalis (500), and catheters (1) (502), (2) (506), and coaxial aligner (512). Process Step 8A: FIG. 6A is an illustration of an exemplary embodiment of a tissue stabilizer (balloon catheter) where the excised tissue is impaled onto its respective catheter and pulled proximally into the inner lumen / mouth of the cutter before resheathing the cutter. FIG. 6B is an illustration of an exemplary embodiment of a tissue stabilizer (balloon catheter) of FIG. 6A where the excised tissue is impaled onto its respective catheter and pulled proximally into the inner lumen / mouth of the cutter by a coaxial aligner before resheathing the cutter. FIGS. 6A and 6B also show the guidewire (601), fossa ovalis (600), and catheter (1) (602). Process step 8A is represented as an exemplary embodiment of the step of FIGS. 6A and 6B as follows: A. As in FIG. 6A, the tissue stabilization element (604) is at least partially deployed. B. As in FIG. 6B, a tissue stabilization element (e.g.: balloon catheter) - the excised tissue (603) is impinged onto its respective catheter and catheter (2) (606) is pulled proximally and optionally into the inner lumen / mouth of cutter (608). C. The cutter is resheathed via: i. pulling the cutter back (proximal movement) into the delivery catheter (3) (610) while maintaining alignment with the coaxial aligner (612); or ii. Advance the delivery catheter through the cutter. Alternative Process - Step 8B: A. The cutter is resheathed via: i. Pulling the cutter back into the delivery catheter (proximal movement), or ii. Advancement of the delivery catheter through the cutter. B. The tissue stabilization element is at least partially retracted to the diameter of the delivery catheter. C. The tissue stabilizer, along with the excised tissue, is pulled back proximally (along with the excised tissue) into the mouth of the delivery catheter.

[0187] Process Step 9: The device assembly (catheter assembly) is removed from the body. In some embodiments, the process of using the device assemblies disclosed herein includes one or more of the following steps. Some of these steps must be performed in a specific order, while some may be performed out of order as alternative process configurations. One embodiment of the order of steps is provided below, but the steps may be rearranged.

[0188] Process Step 1: Vascular access is achieved via the femoral vein using standard placement techniques (Seldinger technique).

[0189] Process Step 2: Transseptal puncture through the fossa ovalis of the interatrial septum is performed using standard placement techniques, leaving the guidewire (4601) in place (illustrated in FIG. 46). FIG. 46 shows an exemplary embodiment of a procedural step using a device assembly disclosed herein, which is a transseptal puncture through the fossa ovalis of the interatrial septum, leaving the guidewire in place.

[0190] Process Step 3: The device assembly is introduced over the guidewire into the right atrium.

[0191] Process Step 4: The guide catheter (4703) is advanced over the guidewire (4701) out of the delivery catheter (4710) and contacted with the septum (4720). Figure 47. Figure 47 shows an exemplary embodiment of a procedural step using a device assembly disclosed herein, where the guide catheter is advanced over the guidewire out of the delivery catheter and contacted with the septum.

[0192] Process Step 5: The shape memory alloy mesh delivery catheter (1) (4802) is introduced over the guidewire into the left atrium and the guidewire is removed. Figure 48. Figure 48 shows an exemplary embodiment of a procedural step using the device assembly disclosed herein, where the shape memory alloy mesh delivery catheter is introduced from the guide catheter over the guidewire through the atrial septum at approximately 90 degrees.

[0193] Step 6: Through the shape memory alloy mesh delivery catheter (1) (4902), the shape memory alloy mesh tissue stabilization element (4904) is introduced into the left atrium where it is deployed by self-expansion (FIG. 49), optionally through the guide catheter (4903). FIG. 49 shows an exemplary embodiment of a step of a procedure using the device assembly disclosed herein, where through the shape memory alloy mesh delivery catheter, the shape memory alloy mesh tissue stabilization element is introduced into the right atrium where it is deployed by self-expansion. In some embodiments, the tissue stabilizer expands outward at an angle of approximately 90° after passing through the septum, the angle being shown in FIG.

[0194] Process step 7: Cutter (5008) (self-expanding shape memory stent with a sharp blade at its distal end) is delivered (sheathed) into the right atrium and the cutter is unsheathed within the right atrium via proximal pullback on the delivery catheter (3) (5010) or by pushing the catheter containing the cutter forward (FIG. 50 AC). FIG. 50 AC shows an exemplary embodiment of a procedural step using the device assembly disclosed herein, where the cutter (self-expanding shape memory alloy stent or lattice with a sharp blade at its distal end) is delivered (sheathed) into the right atrium and the cutter is unsheathed within the right atrium by pullback on the delivery catheter.

[0195] Process step 8: The cutter (5108) translates forward to pierce and cut the septum (5120) while the tissue stabilizer (5104) applies counter tension (FIG. 51). FIG. 51 illustrates an exemplary embodiment of a procedural step using a device assembly disclosed herein, where the cutter translates forward to pierce and cut the atrial septum while the tissue stabilizer applies counter tension.

[0196] Process step 9: The blade catheter, guide catheter (5203), shape memory alloy mesh delivery catheter, cutter (5208), excised tissue (5220), and shape memory alloy mesh tissue stabilizer (5204) are all packaged within the delivery catheter (3) (5210), leaving the tissue trapped between the mouth of the cutter (5208) and the mesh tissue stabilizer (5204), or trapped within the mouth of the cutter (5208) with the mesh tissue stabilizer surrounding the opening of the blade, and the entire system is removed from the body (FIGS. 52A-52B). FIG. 52A shows an exemplary embodiment of a step in a procedure using the device assembly disclosed herein, where the blade catheter, guide catheter, shape memory alloy mesh delivery catheter, tissue cut, and shape memory alloy mesh tissue stabilizer are all withdrawn from the atrial septum. FIG. 52B shows an exemplary embodiment of a procedural step using the device assemblies disclosed herein, where the blade catheter, guide catheter, shape memory alloy mesh delivery catheter, tissue cutting, and shape memory alloy mesh tissue stabilizer are all placed within the delivery catheter just before the entire system is removed from the body.

[0197] In some embodiments, the approximately 90 degree angle is in the range of 80-100 degrees, 85-95 degrees, or 75-105 degrees. In some embodiments, the angle is relative to the septum or portion of the septum being cut or pierced. In some embodiments, the angle is between the axis of the mesh delivery catheter (axis l in FIG. 49) and the septum. In some embodiments, the axis of the mesh delivery catheter is in a portion of the mesh delivery catheter proximate to the septum. In some embodiments, the axis is approximately straight. In some embodiments, the axis connects to a center point of the mesh delivery catheter at its distal tip or faces another center point proximal to its distal tip. In some embodiments, the axis is approximately perpendicular to the septum. In some embodiments, the axis is approximately perpendicular to the portion of the septum being cut or pierced.

[0198] In some embodiments, the device assembly disclosed herein includes a shape memory alloy mesh in relation to one or more catheters. In some embodiments, as shown in FIG. 36, the device assembly disclosed herein includes a shape memory alloy mesh catheter (3604), a shape memory alloy mesh-containing catheter (1) (3602), or both. FIG. 36 also shows a guide catheter (3603), a cutter (3608), and a delivery catheter (3) (3610). In some embodiments, the shape memory alloy mesh has one or more imaging markers. In some embodiments, the shape memory alloy mesh is not as stiff as the guidewire. In some embodiments, the shape memory alloy mesh is reinforced. In some embodiments, one or more catheters of the assembly are not advanced over the guidewire. In some embodiments, all internal catheters of the assembly are advanced over the guidewire. In some embodiments, the guidewire needs to be removed from the body after the initial puncture at the atrial septum crosses an internal catheter (e.g., a guide catheter, or a catheter containing a shape memory alloy mesh). In some embodiments, the shape memory alloy mesh catheter cannot be advanced over the guidewire. In some embodiments, the braid catheter 2 3606 or the containment catheter 1 3602 cannot be advanced over the guidewire.

[0199] FIG. 41A-E shows an exemplary embodiment of sequential procedural steps of applying a device assembly as disclosed herein. Referring to FIG. 41A-E, in some embodiments, a guidewire (4101) is optionally pre-placed via a transseptal puncture. In some embodiments, the guidewire has a stiff material such that its stiffness is greater than the rest of the assembly. In some embodiments, the guidewire is stiffer than the catheters of the assembly. In some embodiments, a guide catheter (4103) is optionally delivered to the atrial septum and, optionally, over the guidewire without the shape memory alloy mesh catheter (4104) into the right atrium. The shape memory alloy mesh-containing catheter (4102) is then advanced across the atrial septum into the left atrium. The guidewire is then optionally removed from the body. Optionally, the guidewire remains in the body until the device assembly is removed after the procedure. In some embodiments, the guidewire extends to the left atrium. In some embodiments, the shape memory alloy mesh catheter is inserted through the containment catheter and the distal edge is delivered to the left atrium; then the shape memory alloy mesh disk, valve, plug, or combination thereof is optionally unsheathed or expanded by pushing the self-expanding portion past the containment catheter in the left atrium. In some embodiments, the disk sandwiches the atrial septum, or all of the disk is left in the left atrium. Optionally, the proximal edge of the expanded shape memory alloy mesh is then pulled against the atrial septum, thus sandwiching the atrial septum between the distal edge of the guide catheter and the proximal edge of the stretched shape memory alloy mesh. Following this step, the cutter is unsheathed or expanded by advancing the blade catheter beyond the tip of the delivery catheter and / or by pulling the delivery catheter behind the self-expanding portion of the blade. The shape memory alloy mesh disk, valve, plug, or combination thereof is pulled proximally to the atrial septum while the braid catheter is translated forward through the atrial septum to create a complete circumferential cut following the guide catheter.The shape memory alloy mesh plug is then pulled proximal to the mouth or opening of the expandable blade, sandwiching the resected tissue between two adjacent disks, valves, plugs, or combinations thereof, or between one disk, valve, plug, or combination and cutter, to ensure tissue capture and retrieval. In some embodiments, the blade catheter, guide catheter, and shape memory alloy mesh-containing catheter are pulled into the delivery catheter, and then the shape memory alloy mesh catheter cuts the tissue together inside the delivery catheter. In some embodiments, the shape memory alloy mesh disk is left at the distal edge of the delivery catheter to block its mouth during removal, to ensure safe capture of tissue during removal of the device assembly.

[0200] FIG. 42A-F shows an exemplary embodiment of a sequential process of using a device assembly as disclosed herein, resulting in the placement of a dog-bone shaped expandable tissue stabilizer sandwiching the atrial septum. Referring to FIG. 42A-F, in some embodiments, the device assembly is delivered over a guidewire (4201) into the right atrium. In some embodiments, a shape memory alloy mesh-containing catheter (4202) is advanced through a guide catheter (4203) across the atrial septum into the left atrium. The guidewire is then removed from the body. A shape memory alloy mesh catheter (4204) is inserted through the containing catheter and delivered into the left atrium; a shape memory alloy mesh disk, valve, or plug is unsheathed by pushing a first self-expanding proximal edge of the shape memory alloy mesh catheter beyond the mouth of the shape memory alloy mesh-containing catheter in the left atrium, or by unsheathing the shape memory alloy mesh-containing catheter in the left atrium to deploy the shape memory alloy mesh disk, valve, or plug. The proximal edge of the expanded shape memory alloy mesh disk is then pulled flush with the atrial septum by pulling the shape memory alloy mesh catheter proximally. The shape memory alloy mesh containing catheter is pulled proximally into the right atrium to unsheath the second disk, valve, or plug, thus sandwiching the atrial septum between the two disks, valves, or plugs. The distal portion of the guide catheter (4203) is then brought into contact with the proximal edge of the unsheathed shape memory alloy mesh disk in the right atrium. The cutter is unsheathed by advancing the blade beyond the delivery catheter or by pulling the delivery catheter behind the self-expanding portion of the blade. The blade is then translated optionally through the atrial septum to make a complete circumferential cut.The shape memory alloy mesh disk, valve, or plug is then pulled into the mouth of the expandable blade, with the resected tissue sandwiched between two adjacent disks, valves, or plugs, or between one disk, valve, or plug and the cutter, to ensure tissue capture or retrieval. In some embodiments, the blade catheter, guide catheter, and shape memory alloy mesh-containing catheter are pulled into the delivery catheter, and the shape memory alloy mesh catheter then cuts the tissue together inside the delivery catheter. The distal shape memory alloy mesh disk is left at the distal edge of the delivery catheter to block its mouth during removal, to ensure safe capture of tissue during removal of the device assembly.

[0201] In some embodiments, after tissue capture, the cutter is resheathed (with tissue captured therein) by advancing the delivery catheter (over the blade). In some embodiments, the blade is resheathed by pulling the blade into the delivery catheter. In some embodiments, the shape memory alloy mesh comprises a diameter of about 4 mm to about 10 mm (range 3 mm to 12 mm) in its expanded state. In some embodiments, the diameter is about 3 mm to about 5 mm, about 4 mm to about 6 mm, about 5 mm to about 7 mm, about 6 mm to about 8 mm, about 7 mm to about 9 mm, about 8 mm to about 10 mm, or about 9 mm to about 12 mm, up to about 12 mm, up to about 11 mm, up to about 10 mm, up to about 9 mm, up to about 8 mm, up to about 8 mm, up to about 7 mm, up to about 6 mm, or up to about 5 mm. In some embodiments, the shape memory alloy mesh catheter features one or more disks, valves, or plugs that serve as a fail-safe: 1) to ensure that the resected (partially resected) tissue does not dislodge from the atrial septum and the device, and 2) to allow the blade to continue translating through the atrial septum in the unlikely event that one of the mesh disks, valves, or plugs is inadvertently pulled through the atrial septum before a full circumferential cut is completed. In some embodiments, the shape memory alloy mesh-containing catheter is used to sheathe and unsheath the shape memory alloy mesh catheter. In some embodiments, the shape memory alloy mesh catheter includes one to three disks, valves, or plugs. In some embodiments, in the expanded state, there is a distance between adjacent disks, valves, or plugs. In some embodiments, the diameter of all disks, valves, or plugs is smaller than the diameter of the distal opening or mouth of the cutter. In some embodiments, the diameter of one or all disks, valves, or plugs is larger than the diameter of the distal opening or mouth of the cutter. In some embodiments, all of the disks, valves, or plugs enter the left atrium.I...

Claims

1. 1. A device assembly for treating heart failure, comprising: The device assembly comprises: a first catheter having a first lumen; a tissue stabilizer attached to the first catheter and positioned along a length of the first catheter; a second catheter having a second lumen slidably engaged on the first catheter; a cutter attached to the second catheter; The tissue stabilizer is configured to sandwich an atrial septal wall between the tissue stabilizer and the cutter and to tent the atrial septal wall into the second lumen.

2. The device assembly of claim 1, wherein the tissue stabilizer is configured to be retracted to engage the atrial septal wall with the cutter, bend the tissue stabilizer toward the distal end of the first catheter, and draw the atrial septal wall into the second lumen.

3. The device assembly of claim 1, wherein the dimensions of the cutter are 1% to 15% larger than the dimensions of the tissue stabilizer.

4. The device assembly of claim 1, wherein the diameter of the tissue stabilizer is smaller than the diameter of the cutter thereby enabling tenting of the atrial septal wall, and the opening formed by the cutter is configured to be larger than the diameter of the cutter.

5. A device assembly as described in claim 1, further comprising a coaxial guide wire slidably engageable within the first lumen of the first catheter.

6. The device assembly of claim 5, wherein the coaxial guidewire is configured to extend from the distal end of the first lumen of the first catheter and pass through an initial puncture site in the atrial septal wall between the right and left atria of the mammalian heart approximately at the fossa ovalis to provide a working path for the device assembly to enter the left atrium.

7. The device assembly of claim 6, wherein the distal end of the first catheter is configured to traverse along the trajectory of the coaxial guide wire and pass through the initial puncture site in the atrial septal wall, such that the tissue stabilizer also extends beyond the atrial septal wall into the left atrium.

8. A device assembly as described in claim 1, further comprising a coaxial alignment element.

9. The device assembly of claim 1, wherein the cutter has an open-ended cylindrical structure.

10. A device assembly as described in claim 1, wherein a distal end of the first lumen includes a puncture tip configured to penetrate the atrial septal wall.

11. The tissue stabilizer comprises: Tyne, At least one bent wire; At least one support, or Combinations of these The device assembly of claim 1 , comprising:

12. The cutter material comprises: Nitinol, Nickel-titanium, stainless steel, Copper-aluminum-nickel, Zinc-gold-copper, or Combinations of these The device assembly of claim 1 , comprising a shape memory alloy comprising:

13. The tissue stabilizer material comprises: Nitinol, Nickel-titanium, Copper-aluminum-nickel, or Zinc-gold-copper, The device assembly of claim 1 , comprising a shape memory alloy comprising:

14. The device assembly of claim 1, further comprising a delivery catheter having a central delivery lumen.

15. The device assembly of claim 14, wherein the delivery catheter is steerable or bendable.

16. The device assembly of claim 14, wherein the first catheter is slidably engaged within the central delivery lumen.

17. The device assembly of claim 14, wherein the second catheter is slidably engaged within the central delivery lumen.

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