Transseptal systems, devices, and methods

Abstract

Anatomical wall crossing systems, devices, and related methods are disclosed in this patent document. An interatrial septum system may include, for example, a guidewire, a dilator, and a deflectable sheath, which is configured to safely deliver a puncture needle through an interatrial septum associated with the fossa ovalis and into a central region of the left atrium of the heart. The dilator may include a dilator nose having a first outer diameter and a dilator bevel section extending proximally from the dilator nose, which tapers from a second larger outer diameter to the first outer diameter. The lengths and interactions of the puncture needle and the dilator nose may be configured such that the puncture needle is inhibited from bending during use and striking the left side of the interatrial septum of the heart. The body of the guidewire may include at least one loop segment to provide stable support in the left atrium for delivering a diagnostic or therapeutic device along its more proximal portion. The deflectable sheath may position and align the dilator nose relative to the fossa ovalis.

Description

[0001] Priority Claim

[0002] The present application claims the benefit of priority of U.S. Provisional Patent Application Ser. No. 62 / 840,062, filed Apr. 29, 2019, and entitled “TRANSSEPTAL GUIDEWIRE NEEDLE TIP,” which is incorporated herein by reference in its entirety. Field of the Invention

[0003] The present subject matter particularly relates to medical devices for accessing left heart structures by crossing the septum of the heart. Background of the Invention

[0004] Transseptal puncture can be used to access the left atrium (LA) of the heart through the right atrium (RA). For example, atrial fibrillation ablation therapy and more recently the treatment of valvular septum and other structural heart diseases often require access to the LA.

[0005] Abbreviation

[0006] Unless otherwise indicated, the following abbreviations apply throughout this disclosure:

[0007] · FO: fossa ovalis 202

[0008] · Fr: French (increment of catheter size diameter)

[0009] · GW: guide wire 10

[0010] · LA: left atrium 208

[0011] · LAA: left atrial appendage 210

[0012] · MRI: magnetic resonance imaging

[0013] · MV: mitral valve 212

[0014] · RA: right atrium 206

[0015] · TEE: transesophageal echocardiogram

[0016] · TTE: transthoracic echocardiogram

[0017] Overview

[0018] The present inventors recognize that a transseptal access system and device should be able to reliably locate a specific location on the fossa ovalis (FO) (a recess on the right side of the interatrial septum between the right atrium (RA) and left atrium (LA) of the heart) to safely and accurately puncture the septal wall during a given procedure. Unintentional puncture of structures such as the aorta, the free wall of the left or right atrium, or the pulmonary veins can result in cardiac perforation and tamponade. In addition, some left heart procedures require traversing a highly specific septal wall site associated with the FO to precisely locate a specific target for positioning diagnostic or therapeutic devices.

[0019] The present inventors also recognize that existing transseptal access systems and devices have deficiencies including, but not limited to: (1) the challenge of achieving engagement with precision and stability at a specific location on the FO; (2) the challenge of advancing the needle across the septal wall; (3) the challenge of dealing with redundant or aneurysmal septa adjacent to the free wall of the LA and thus at risk of perforation and pericardial tamponade such that the apex of the elevated needle remains on the FO; and (4) the challenge of dealing with prior septal occluder placement, which requires alternative puncture locations on the native septum or direct puncture of the occluder.

[0020] The present subject matter particularly pertains to achieving transseptal access in an efficient and safe manner to enter the LA through a guide wire (GW) that includes a distal needle segment, an intermediate annular or coiled left atrial segment, and one or more linear elongated proximal segments, and that serves as a platform for delivering a structure or other device to the LA of the heart. Specifically, the present subject matter pertains in part to a transseptal GW 10 incorporating a transseptal puncture needle 12. The GW 10 can include a relatively rigid proximal segment end 16 and an intermediate loop segment 14, where the distal end 22 includes a node having the transseptal needle 12. One or more intermediate segment GW loops 24, 26 can come to rest in the LA 208. The intermediate loop segment 14 can be formed of a shape memory material to form at least two loop segments, such as a second, more distal, generally outer wide coil 24 and a first, more proximal, inner coil 26, where the intermediate segment 14 can be connected to the elongated linear rigid GW segment 16 at the proximal end 25, which ultimately rests externally for exchange.

[0021] The present subject matter also pertains to a transseptal GW puncture system that can pass through FO 202, the transseptal GW puncture system including a GW 10, a transseptal dilator 108, and a sheath 100. The distal end of the GW 10 may include a transseptal needle 12 that is attached at its distal end 22 to a looped GW segment 14 and may then be positioned to be connected to the distal end 17 of a linear stiff GW segment 16. The transseptal needle 12 may have shape memory at the attachment point to the looped GW segment 14, where the shape memory is sufficient to maintain a pre-specified angle of the transseptal needle 12 relative to the looped GW segment 14 to maintain atraumatic stability within and central to the loops 24, 26. One or more of the loops 24, 26 may be positioned and stabilized within the LA 208 such that they rest adjacent to the inner surface of the LA 208. The intermediate looped segment 14 may be formed of a shape memory material to form two loops 24, 26, where the proximal end 25 of the more proximal coil 24 is connected to the proximal elongate stiff segment of the GW 16, and where a secondary bend 29 may be positioned within the RA 206 such that it transitions to the elongate linear proximal most segment of the GW 10.

[0022] The transseptal dilator 108 may include an elongate catheter 109 that is disposed within the sheath 100 and that tapers to a narrow dilator distal segment 110, where the catheter lumen 111 remains compatible with the GW 10 throughout, and the GW may have an overall spectrum of diameters ranging from 0.021 - 0.035 inches inclusive or more. A radiopaque marker 122 may be located at a point along the distal segment 106 and is positioned to overlap with the radiopaque tip marker 123 on the sheath 100 when the transseptal dilator 108 and the sheath 100 have equal outer diameters at that point. The dilator 108 may be advanced forward to an exact position on the FO 202 to "bump up" the FO 202 by a series of forward movements at the distal end of the handle 104 adjacent to the actuator 112. Steerable manipulation of the proximal sheath handle 104 may permit antegrade and retrograde bending and may perform a torsional front or back section of the entire sheath 100 to position the distal end 124 of the sheath and the held dilator tip 110 adjacent to a particular FO site during a particular procedure. Forward and retraction movements of the dilator distal segment 110 relative to the stable sheath 100 with the actuator 112 used on the proximal sheath 100 may interact with the proximal end 119 of the dilator 108.

[0023] Once the FO 202 is elevated using the dilator 108 containing the septal needle 12, the needle 12 can be advanced forward, thereby piercing the FO septum 202 and entering the LA 208. The septal needle 12 can be folded or bent from the shape memory at the hinge point 20 on the coiled GW segment 14 at a discontinuous angle and will connect to the coiled GW segment after the septal needle is advanced forward beyond the FO 202. This can form an angle within a range of approximately 45 degrees to 140 degrees (including the end values). Further advancement of the septal GW 10 can position the coils of the annular segment 14 of the GW 10 within the LA chamber 208, thereby also assisting in keeping the needle position safely in the central LA 208 by remaining in the center of the ring. Preferably, the GW coils 24, 26 have a smaller inner diameter coil 26 and a larger outer diameter coil 24, thereby assisting in keeping the needle 12 in the center of the LA 208. The smaller diameter inner coil can prevent the needle 12 from damaging the tissue in the LA wall. In another embodiment, the coils 24, 26 can have equal diameters.

[0024] In another embodiment, the coils 24, 26 can be offset, as Figure 3 and Figure 4 shown, to further assist in retaining the central position of the needle 12 that can also be folded in the third dimension at that time. When the folded distal septal needle 12 is advanced and deflected centrally, additional features make the needle less susceptible to the perforated LA 208 structure, thereby further assisting in maintaining the central needle 12 position within the offset, but the rings 14 are equally spaced. The coils 24, 26 can be offset by approximately 0.75 cm - 2 cm (including the end values). The coils 24, 26 can have a medium degree of stiffness, thereby allowing for less traumatic interaction with the wall without the LA. The secondary bend 29 in the right atrial GW segment can assist in crossing the FO 202 and coaxially keeping the vertical trajectory in the IVC 215. For example, the elongated proximal rigid GW segment 16 can have a length of 260 cm, but can be significantly longer for the purpose of catheter or device exchange.

[0025] The forward positioning of the system of the present subject matter allows for precise positioning of the distal sheath to achieve precise device positioning, and in turn establish an optimal LA 208 positioning ultimately determined by a specific left heart target of a given device (i.e., LAA 210, MV 212). By using repeated dilator advancement under echo or other imaging guidance, the system intuitively and simply positions accurately on a specific FO 202 target. After the coil has been advanced past the FO 202 and fixed in the LA 208, the dilator 108 can then be advanced through the coiled GW 10 into the LA 208, leaving the overlapping radiopaque segments in place until the sheath 100 has been advanced into the LA 208. The overlapping radiopaque markers 122, 123 on the distal dilator tip 106 and the sheath tip 124 can be used to confirm that they are of equal diameter for smooth simultaneous advancement of the dilator 108 and the sheath 100 past the FO 202.

[0026] The deflectable and steerable nature of the sheath 100 may permit the sheath 100 to obtain directivity, angulation, and reach of various RA 206 sizes and FO 202 angles in a variety of patient-specific anatomies using a single-sized forward-looking catheter system.

[0027] The set system preferably includes a needle GW 10 delivered by an "all-in-one" catheter system for repeatedly advancing a dilator 108 containing a retractable needle 12 to an exact eminence position on the FO 202. An actuator 112 on the sheath 100 adjacent to the handle 104 may permit highly controlled advancement of the distal segment 110 to "eminence" the FO septum prior to needle puncture. The actuator 112 can be advanced or retracted with the operator's thumb without removing the operator's hand from the rotatable handle 104. The dilator 108 may have a more flexible distal segment to permit smooth tracking of the coiled GW segment in the LA 208. The deflectable sheath tip 124 may have monopolar or bipolar directivity. The deflectable sheath 100 may (for example) have a distal fixed 2-degree bend within the RA 206, and the range of this bend can be from 2 degrees to 20 degrees (including the end values) to more easily establish perpendicularity with the FO 202. Standard commercially available sheath dilator catheters can also be used in combination with the aforementioned novel needle GW.

[0028] Advantageously, the present subject matter provides a system and device that meet the following: (1) improved ease of use; (2) intuitive manipulation for precise distal control; (3) improved device and procedural efficacy; (4) increased device safety across a wide range of operator skills; (5) enhanced workflow and reduced procedural time; and (6) reduced procedural costs secondary to the combined needle GW.

[0029] These and other embodiments and features of the subject matter will be set forth at least in part in the following detailed description. This summary is intended to provide non-limiting embodiments of the subject matter and is not intended to provide an exclusive or exhaustive explanation. The following detailed description is included to provide further information regarding the subject matter. Summary of the Invention

[0030] An anatomical wall crossing system is provided that includes: a dilator that extends from a proximal end portion having a first outer diameter to a distal end portion and includes a lumen therethrough, the distal end portion including a dilator distal tip, a dilator nose, a dilator bevel segment, a dilator shoulder, a dilator alignment zone, and a dilator waist, the dilator nose extending within the dilator bevel segment and attached thereto, the dilator nose having a second outer diameter that extends from the dilator bevel segment to the dilator distal tip, the dilator bevel segment extending proximally of the dilator nose and tapering from the dilator shoulder to the second outer diameter of the dilator nose, the dilator alignment zone having a consistent outer diameter and extending proximally from the dilator shoulder, the dilator bevel segment having a third outer diameter at a proximal end of the dilator bevel segment, the third outer diameter being equal to the first outer diameter and greater than the second outer diameter, and the dilator waist extending proximally of the dilator alignment zone, the dilator waist having a greater longitudinal flexibility than the dilator alignment zone and having an outer diameter that is 30% to 95%, inclusive of the end values, of the third outer diameter of the dilator alignment zone. A distal radiopaque marker is placed near the dilator distal tip, and a shoulder radiopaque marker is located on the dilator shoulder. Brief Description of the Drawings

[0031] In the drawings, the same numbers may be used throughout the several views to describe like features and components. The drawings generally illustrate, by way of example and not limitation, the various embodiments discussed in this patent document.

[0032] Figure 1 is a side plan view of a first embodiment of the subject matter of a combined transseptal needle and GW.

[0033] Figure 2 is a side plan view of a second embodiment of the subject matter of a combined transseptal needle and GW.

[0034] Figure 3 is a side plan view of a third embodiment of the subject matter of a combined transseptal needle and GW having an offset loop.

[0035] Figure 4 is a front plan view of a Figure 3 transseptal needle that has been rotated ninety degrees.

[0036] Figure 5 is a side plan view showing a representative deflectable sheath for use with the needle-GW of the present subject matter.

[0037] Figure 6 is showing in association with Figure 5 a side plan view of a dilator for use with a deflectable sheath.

[0038] Figure 7 is a schematic front view representation of the human central venous circulation system including a heart and a vein system having a deflectable sheath of the present subject matter.

[0039] Figure 8 is a schematic front view representation of a cross-section of a human heart having a deflectable sheath that is positioned across the atrial septum and positioned in the FA, wherein the distal needle GW loop is located in the FA.

[0040] Figure 9A is a cross-sectional view of the distal region of a dilator and has a distal end of a guide wire and a needle received within the lumen of the dilator.

[0041] Figure 9B is a cross-sectional view of the distal region of a dilator extending around a radius of curvature with the needle body and needle tip received within the lumen of the dilator.

[0042] Figure 10A is a side view of the distal end of a guide wire, a needle, and a hinge point therebetween.

[0043] Figure 10B is a side view of the distal end of a guide wire forming a needle-guide wire angle with the needle body.

[0044] Figure 10C is a side view of a smaller diameter cylindrical hinge point located between the distal end of a larger diameter guide wire and the needle body.

[0045] Figure 10D is a side view of a rectangular hinge point located between the distal end of a cylindrical guide wire and the needle body.

[0046] Figure 10E is a side view of a rectangular hinge point bent to a needle-guide wire angle along a hinge bending axis.

[0047] Figure 11A is a cross-sectional view of the distal region of a dilator with the guide wire needle surrounded by a tip sheath received within the lumen of the dilator.

[0048] Figure 11B is a side view of a releasable tip sheath.

[0049] Figure 11C is a cross-sectional view of a releasable tip sheath received within the lumen of a dilator.

[0050] Figure 12 Is a side view of a transseptal guidewire having a proximal guidewire segment, a guidewire loop segment, and a needle.

[0051] Figure 13 Is a cross-sectional view of a dilator having a dilator nose, a dilator alignment zone, a dilator waist, and a dilator lumen that extends to a dilator proximal port located on a dilator manifold.

[0052] Figure 14A Is a cross-sectional view of a transseptal guidewire located within a dilator that is located within a deflectable sheath, with the dilator nose forming a bulge of the FO.

[0053] Figure 14B Is a cross-sectional view of a needle that is partially received within the dilator nose and extends beyond the FO wall.

[0054] Figure 14C Is a cross-sectional view of the dilator nose moving forward beyond the FO wall while the guidewire and needle are held in place fixed within the deflectable sheath.

[0055] Figure 14D Is a cross-sectional view of the needle moving forward beyond the FO wall and a guidewire-needle bend angle occurring at the hinge point.

[0056] Figure 14E Is a cross-sectional view of the guidewire moving further forward beyond the FO wall and forming a guidewire loop segment within the LA.

[0057] Figure 14F Is a cross-sectional view of deflecting the sheath and the dilator forward via the transseptal guidewire to place a portion of the sheath into the LA.

[0058] Figure 15 Is a cross-sectional view of a forward movement method of slightly moving the guidewire forward and then slightly moving the dilator forward to cross the thickened FO.

[0059] The figures are not necessarily to scale. Some features and components may be shown exaggerated in scale or in schematic form, and some details may not be shown for clarity and conciseness. Detailed Description

[0060] Referring to the reference numerals in the drawings, the transseptal puncture system of the present subject matter is preferably (but not limited to) an "all-in-one" system, whereby a single-size system can be used in a variety of anatomical configurations and atrial sizes. The system includes dedicated components, including an exchange GW having a distal transseptal needle and a neighboring coil or loop for securing the GW in the LA 206. Additionally, the system can include a dilator that interacts with an actuator on a proximal sheath handle for controlled positioning on the FO with the assistance of a deflectable sheath.

[0061] Guide wire 10

[0062] Now referring to the illustrated septal needle - GW 10 Figures 1 to 4 . The septal needle - GW 10 can be an integrated component, which can avoid the need for a separate septal needle and multiple GW exchanges, lengths, and curves to handle various anatomies. The septal needle - GW 10 can have at least three defined segments: (1) a distal septal needle 12; (2) an intermediate or annular LA segment 14; and (3) a proximal elongated linear rigid segment 16.

[0063] Needle 12

[0064] The septal needle 12 can be positioned to be connected to the distal end 22 of the GW loop segment 14. The septal needle 12 is preferably relatively short, with a length between about 0.75 cm - 2.0 cm (including the end values). The needle 12 can have an ultra - low profile tip 18. The proximal end 20 of the needle 12 can be connected to the adjacent distal loop segment 14, which can be configured to be linear when held in the central lumen 111 of the dilator tip before advancement.

[0065] The septal needle 12 can have a smooth coating to minimize resistance and a sharp conical tip 18 for puncturing and easily transferring across the FO202 (illustrated in Figure 8 ), where the FO can include an FO that can be densely scarred or aneurysmal. Unintentional needle protrusion across the FO septum and loss of the preferred puncture site can be avoided by the ultra - fine tip on the needle tip 18 and by slowly and repeatedly delivering the forward - viewing conical septal dilator 108 into the FO 202 to stably position and "bulge" the septum through the dilator tip 18, which is in turn supported by the deflectable septal sheath 100. Under this forward - viewing system, unintentional anterior or posterior torsional forces that cause sliding across the FO 202 can be greatly minimized.

[0066] The septal needle 12 can preferably be composed of a metallic material such as stainless steel or an alloy including a nickel - titanium alloy with shape memory, and can be attached to the GW loop segment 14 by welding or possibly interdigitated slots that interact to form a more stable yet flexible living joint, allowing the needle to fold over itself and thus avoid piercing the LA free wall, pulmonary veins, etc. Other means of creating a pre - formed angle between the needle 12 and the loop segment 14 can also be conceived and utilized.

[0067] The transseptal needle 12 can form an acute angle at its proximal end / hinge point 20 that is connected to the distal end 22 of the annular GW segment 14, maintaining a pre-specified angle with the center of the LA loop segment 14. This thus maintains atraumatic stability within the central LA loop segment 14 and prevents contact and possible perforation of the LA 208 structures including the pulmonary veins, LA free wall, and LAA 210.

[0068] After GW advancement and transseptal puncture, the needle 12 can preferably bend sharply at an acute angle with the adjacent annular GW segment 14 in the center, as illustrated in Figures 1 to 4 . The needle 12 can remain linear but bend inward after entering the LA 208, preferably at an angle of about 45 degrees - 140 degrees (including the end values) relative to the distal annular GW segment 14. The diameter of the tip 18 of the transseptal needle can be ground to an ultra-low profile and tapered back to connect to the distal loop segment 14, most likely transitioning to a profile within the range of 0.021 inches - 0.035 inches (including the end values) or larger.

[0069] Guide wire loop segment 14

[0070] The annular GW segment 14 can be designed to stably position the GW 10 in the LA 208 without causing damage and, additionally, assist in protecting the left atrial free wall from unwanted needle punctures. The diameter of two or more loop segments 24, 26 can generally be in the range of about 2.5 cm - 4.0 cm (including the end values) and is formed by shape memory when it exits the transseptal dilator 108 into the LA 208. In one embodiment, the distal GW loop segment 14 can be formed by two circular or non-circular loops of substantially equal size, which also form after being deployed in the LA chamber, as illustrated in Figures 3 - 4 .

[0071] The coil provides at least four useful functions:

[0072] 1. The coil can confirm correct LA chamber positioning by presenting an unconstrained known shape within the LA 208.

[0073] 2. The coil 14 can maintain stable positioning in the LA 208 to avoid inadvertently retracting the GW 10 into the RA 206 or forcefully advancing the needle tip 12 into the LA free wall or pulmonary veins.

[0074] 3. The outer wide coil 24 can provide a longer GW support ramp through which the dilator 108 and sheath 100 can be advanced around a curve into the LA 208 with less resistance to facilitate catheter support.

[0075] 4. The coil can form an outer protective shield where the needle 12, which is kept centered, is at a safe distance from the penetrated LA 208 structures.

[0076] In another embodiment, there are at least two circular coils, with the inner coil 26 having a diameter smaller than that of the outer coil 24, as Figures 1 to 4 shown, and the inner coil is thus centered within the outer coil 24. In this embodiment, the outer coil 24 can be compressed by the LA 208 structure without any configurational change of the inner coil 26, thus further protecting against deformation of the distal needle 12 and retaining its central position. As an example, the inner coil 26 of the GW 10 can have a diameter between about 1.5 cm and 3.0 cm (including the end values), such as about 2.5 cm. The outer coil 24 can have a diameter between about 3.0 cm and 4.0 cm (including the end values), such as about 3.5 cm.

[0077] In a third embodiment, the two coils 24, 26 can have parallel portions 24a and 26a, with unequal diameters and offset by about 0.75 cm to 2.0 cm (including the end values). Additionally, as Figure 5 shown, a second preformed elbow at the junction of the distal spaced needles 12 and a GW loop segment 14 of a third dimension centered between the two offset wire coils 24, 26 can be incorporated. The purpose is to further assist in preventing needle perforation of the LA 208 by allowing the needle 12 to be centered circumferentially not only in two dimensions after bending in this embodiment, but also to be centered in a third dimension between the widths of the two offset loops 24, 26. The distance between the parallel portions 24a and 26a of the coils 24, 26, shown by the dotted line 25, can be (for example) about 1 cm and can be in the range of about 0.75 cm to 2.0 cm.

[0078] Proximal guide wire segment 16

[0079] The proximal GW segment 16 can be connected to the adjacent wire loop segment 14 at the distal end 17 of the segment 16. The proximal GW segment 16 can include a proximal free end 28 that is shown to have sufficient length to permit catheter or device exchange while retaining the distal GW loop segment 14 positioned within the LA. The distal end 17 of the proximal GW segment can be linearly transferred across the interatrial septum into the LA 208. Then there can be a shallow fixed second-degree elbow 29 located generally in the middle RA 206, maintaining a preferred angle of 2° to 20° (including the end values). The elongated proximal stiff GW segment 16 extends from the most distal end of the long proximal segment 17 to the most proximal end 28, having a preferred diameter of 0.021 inches to 0.035 inches (including the end values). The length of the long proximal stiff GW segment 16 can extend 240 cm to 300 cm (including the end values), preferably 260 cm. This long stiff GW segment 16 can be used as a support track for an array of exchange catheters and devices to be delivered to left heart targets.

[0080] Sheath 100

[0081] Reference Figure 5 , the septal delivery sheath 100 can be monopolar or bipolar. For example, it is a deflectable sheath actuated using a rotatable proximal ergonomic handle 104 to achieve up / down bending and a corresponding sheath torque control for optimal front / back positioning. The forward or backward movement of the septal sheath 100 can allow for up and down positioning to achieve controlled and atraumatic guidance in all planes. The sheath 100 can have a proximal end 102 and a distal section 107 positioned adjacent to the actuator 112. Current septal systems designed for commercial use typically enter the field of view from the femoral vein using a clockwise torque of the sheath / dilator system into the FO 202, which can be overly aggressive (too long in length). If the over-sized dilator 108 briefly "gets stuck" distally on the ridge protruding from the atrial septum, this can in turn lead to unintentional "stored" torque. Further movement of the distal section 110 of the dilator positioned within the FO 202 can result in perforation of the free wall or appendage of the RA 206. Conversely, a dilator 108 with insufficient length or "reach" that cannot cross the FO 202 to engage the septum results in failure to puncture the FO 202.

[0082] The sheath 100 can have an ergonomic bidirectional rotatable handle 104 for up-distal sheath flexion and down-distal sheath bending, as depicted by arrow 125, and reaching the tip 124 of the sheath 100. In addition, 1:1 torque transfer distally from the front section to the back section position can be achieved through a braided wire reinforcement of the sheath 100 (not depicted), which can also improve retraction support to enhance device delivery. The sheath 100 can initially be positioned adjacent to the atrial septum but not engaging the atrial septum using fluoroscopy and TEE guidance, and when available, potentially real-time MRI and computed tomography.

[0083] Once the sheath 100 is precisely positioned under imaging guidance at an appropriate short distance (e.g., about 0.5 cm - 2.0 cm) from the FO 202 in the RA 206, the dilator 108 can be advanced while keeping the sheath 100 stationary. The sheath handle 104 and the adjacent actuator 112 for the dilator can allow for system (sheath and dilator) manipulation with one hand held in place without using the operator's contralateral hand. The actuator 112 for the dilator 108 can be manipulated by the operator's thumb or other finger to repeatedly advance forward or retract by interacting with the friction element 121 on the dilator 108. The braided wire-reinforced sheath 100 can provide strong backup and kink-resistant support for precise control of advancing the distal section 110 of the dilator 108 and subsequently the dilator 108 to a specific position within the FO202 in order to "bulge" the septum.

[0084] Sheath 100 preferably includes, but does not require, an expandable shaft to accommodate highly variable device profiles; on the other hand, a series of fixed-diameter sheaths can be used to accommodate multiple device profiles. Desirably, an openable or expandable sheath in the range of about 8.5 Fr to possibly as high as 30 Fr (including the end values) can eliminate the need to maintain multiple sheath diameters available for different procedures. Thus, one embodiment is a single sheath size that is adapted to be expandable within a certain diameter range. An interseptal sheath that may require expandability at two or more distances from the proximal handle may preferably be used to deliver devices around complex or multiple curves.

[0085] A number of other support structures can linearly extend within the sheath body to retain sufficient support levels for subsequent device delivery on more angulated anatomies. For example, a secondary bend of 2 degrees - 20 degrees can be positioned proximal to a more distal deflectable tip, which can assist in achieving a more perpendicular angle at the FO to achieve stronger coaxial back-up support. Additionally, this can permit a distal bend of greater than 180 degrees, which may sometimes be required to achieve proper sheath positioning within the medial aspect of the left heart. A tight hemostatic valve on the sheath hub 114 can minimize back-leakage around the GW 10, including, for example, a GW as small as 0.021 inches in diameter. Preferably, sheath 100 is 90 cm long (70 cm of usable length) or longer. A hub for locking the dilator to the sheath can be incorporated.

[0086] Dilator 108

[0087] The interseptal dilator 108 can have an ultra-low profile distal section 110 having a reverse taper (shown at 106) that returns to a fixed outer diameter 118 at the distal end of the dilator 108 that is compatible with the inner sheath diameter. The dilator 108 can be advanced forward until it displays a "bulge" of the FO septum at an exact location specific to the position visualized by TEE or by other real-time imaging detectors specific to the procedure being performed.

[0088] In a preferred embodiment, the dilator 108 can interact with an actuator 112 adjacent to the sheath handle 104 via a frictional contact element 121 or using interlocking gears for precise and gentle control of dilator movement. The actuator 112 that permits the dilator to be advanced or retracted will preferably be controlled with the ipsilateral thumb, thus retaining the ability to manipulate both the dilator 108 and the sheath handle 104 with one hand. The dilator 108 can have variable flexibility along its length, with a more flexible distal section 118 to prevent the catheter system from being over-straightened or displaced when advanced via the GW annulus 14.

[0089] The distal segment 106 of the dilator should be capable of advancing distally beyond the stationary distal sheath 100, preferably by about 5 cm, but this can be varied to extend beyond the sheath tip by about 3.0 cm - 8.0 cm (including the end values). This allows the dilator 108 to be advanced controllably across the FO 202 and into the LA 208 via the distal GW 10. After the septal puncture and the advancement of the dilator 108 into the LA 208, while maintaining the sheath 104 fixed in the RA 206, there should be sufficient space until the radiopaque markers 122, 123 overlap on the septal RA 206 side. Thereafter, the composite system of the transseptal dilator 108 and sheath 100 with a flush outer diameter can now be advanced as a single unit into the LA 208. The distal segment 106 of the dilator terminates in a low-profile tip 110 and may have a radiopaque marker 122 proximal to the distal segment 106 of the dilator, which matches the profile of the radiopaque marker 123 on the sheath tip 124, presenting a smooth transition point between the two for simultaneous advancement across the FO 202, thus preventing the sheath tip edge from "hanging up" at the interatrial septum crossing point.

[0090] Method of use

[0091] Reference Figure 7 and Figure 8 For an exemplary method of operation on a human patient 201, it can be as follows. As described below, this technique is generally guided by TEE or TTE supplemented with standard fluoroscopy. It should be understood that the procedure can also be guided by intracardiac echo, real-time MRI, or image integration of preoperative volume-rendered computed tomography images. For this latter imaging method, using standard fluoroscopy images, pre-acquired computed tomography images can be oriented to the standard fluoroscopy images and superimposed on the standard fluoroscopy images for guidance. Refer to U.S. Patent 8,900,214 to Nance et al., which is incorporated herein, for a general description of the human anatomy including the heart 200 and the insertion of the transseptal sheath 100 into the atrial region.

[0092] Using fluoroscopy, a 0.032-inch J-tip GW is advanced from the right femoral vein 216 into the superior vena cava 218. The deflectable sheath 100 and dilator 108 are advanced as a unit via the J-tip GW 10 and positioned in the mid-RA 206. The J-tip GW 10 is removed and the dilator 108 is flushed. Then, under fluoroscopy, the distal tip 18 of the GW 10 is advanced into the 0.032-inch compatible dilator 108, and the distal tip 18 of the GW 10 is positioned proximal to the distal segment 110 of the dilator.

[0093] The ergonomic handle 104 on the sheath 100 is axially oriented to permit the deflectable tip 124 to bend forward toward the FO 202. Before maneuvering the sheath 100 toward the FO 202, a 1 cm to 3 cm dilator 108 is advanced distally to fix the sheath 100 via fluoroscopy and echocardiogram. To achieve the anterior or posterior orientation, the sheath 100 is twisted forward or backward. The sheath 100 is advanced or retracted to obtain a more superior or inferior position. Similarly, the proximal sheath handle 104 is rotated to bend the distal tip 124 to a superior (i.e., retrograde) or inferior (i.e., antegrade) trajectory. The TEE probe is most commonly used to optimally image the FO 202 and the adjacent dilator distal tip 110 using orthogonal views: a bi-caval view for superior-inferior orientation and a short-axis view at the aortic level to demonstrate anterior-posterior positioning. Using these TEE views, the precise position for the procedure-specific puncture on the FO 202 can be obtained. The actuator 112 adjacent to the sheath handle 104 is used to slowly and repeatedly advance the dilator tip 110, thereby creating a "bump" within the FO 202 and the correct position confirmed by TEE. If the dilator distal tip 110 is not correctly positioned, the dilator 108 can be retracted together with the actuator 112 and re-directed after maneuvering the sheath 100.

[0094] In the case of correct positioning confirmed using the bump position, the proximal end of the GW 10 is advanced and the needle tip 18 punctures and crosses the FO 202 septum. As the GW 10 is further advanced, the needle 12 sharply bends at the hinge point 20 of its loop segment 14 attached to the GW 10. As the GW 10 is further advanced, its distal coil 14 self-aligns within the LA 208, and the needle 12 remains bent at the center of the coils 24, 26. The catheter is continuously aspirated and flushed by exchange. As soon as the GW loop segment 14 is advanced into the LA, the patient is heparinized therapeutically. The correct positioning of the GW 10 is confirmed by verifying its preformed shape. The coiled or looped segment 14 can assume several different embodiments as described herein. The dilator 108 is advanced via a coiled silk thread to maintain the sheath 100 in a fixed position within the RA 206.

[0095] In the case of advancing the dilator 108 of an appropriate length under fluoroscopy, the radiopaque markers 122, 123 on the dilator 108 overlap with the sheath tip 124 within the RA 206, thereby confirming that the outer diameters of the two catheters are equal and ready to be advanced as a single unit into the LA 208. Now the sheath tip 124 rests in the LA 208 beyond the FO 202. Similarly, all maneuvers of the dilator 108 and the sheath 100 are performed as a single-handed procedure. The dilator 108 is removed, leaving the GW silk loops 24, 26 and the sheath 100 stationary within the LA 208.

[0096] The elongated proximal segment of the GW 10 is loaded with the primary device, which is now advanced to the tip of the sheath 124, and the GW 10 is removed. The sheath 100 can then be more finely manipulated to deliver the device to the target and subsequently deploy it. After deployment, the deflectable sheath 100 is pulled back into the RA 206 and then removed from the patient. Heparin and protamine are reversed, and the percutaneous vascular access is closed.

[0097] The transseptal procedure is performed using a forward-looking catheter system that is repeatedly advanced to the exact position of the FO 202 before being punctured. The nature of the catheter system is such that only one device shape will be required to enter the LA 208. This is different from current techniques in which a large number of catheter sizes are used to twist the catheter into the FO 202, which may initially be too small to reach the FO 202 or too long, putting the patient at risk of slipping off the FO septum and potentially piercing the free wall of the RA.

[0098] Guide wire, needle, dilator and sheath

[0099] Figure 9A and Figure 9B An embodiment of the distal end of the guidewire 22 is shown, which can be the distal end of the guidewire loop 14 of the transseptal guidewire 10 of the present subject matter, as described earlier in Figures 1 to 4 The transseptal guidewire 10 can be positioned within the distal expander segment 106 of the expander shaft 109 of the present subject matter. The expander shaft 109 and the distal expander segment 106 have an expander lumen 111 that has an expander lumen diameter 250 that allows the guidewire needle tip 18, the guidewire loop segment 14, and the transseptal needle 12 to easily pass through the expander lumen without significant frictional force. As shown in Figure 9A and Figure 9B The needle body diameter 255 of the needle body 252, which has a diameter shown to be the same as the guidewire diameter 258, is smaller (e.g., by about 0.002 inches) than the expander lumen diameter 250 (in the range of 0.001 inches - 0.004 inches, including the end values). The needle body diameter 255 is not significantly smaller than the expander lumen diameter 250 such that the inner expander bend wall 260 and the outer expander bend wall 265 can contact the needle body 252 and provide alignment of the needle body central axis 270 with the expander central axis 275. The needle 12 can have a needle length of about 5 mm (in the range of 3 mm - 20 mm, including the end values) to provide axial alignment of the needle body 252 coaxial with the expander central axis 275.

[0100] The needle tip 18 can extend from the needle body 252 in a conical or tapered shape to form a sharp needle tip 285 that is capable of penetrating the tissue present in the FO 202 of the atrial septum 204, as shown in Figure 14AAs shown, or can be used to penetrate other positions around the FO perimeter or penetrate other blood vessel walls or organ septa. To allow the needle-guidewire 10 to traverse distally within the dilator lumen 111 without the tip 285 of the needle making a piercing contact with the outer bent wall 265 of the dilator, the needle tip 18 can be formed to have a specified needle tip length 295 and a needle tip angle 300. As Figure 9B shown, the dilator 108 can be bent into a curved shape having a dilator radius of curvature 305. The lower limit of the dilator radius of curvature 305 required to enter the FO 202 from the inferior vena cava 215 (see Figure 8 ) can be about 1 cm (in the range of 0.75 cm - 2 cm (including the end values)). The dilator lumen diameter 250 can be, for example, about 0.035 inches (in the range of 0.026 inches - 0.038 inches (including the end values)); the needle body diameter 255 can be, for example, about 0.030 inches (in the range of 0.025 inches - 0.031 inches (including the end values)). For example, using standard geometric considerations for a dilator 108 with a bend extending around a dilator radius of curvature 305 of 1 cm, it can be shown that a needle tip 18 having a needle tip length 295 of approximately 2 mm and a needle tip angle of 26 degrees (in the range of 8 degrees - 30 degrees (including the end values)) will provide for the travel of the needle tip 18 around the dilator radius of curvature 305 without allowing the tip 285 of the needle to pierce or penetrate into the outer bent wall 265 of the dilator. Various needle tip 18 shapes (such as non-linear surface curvature) and angles can be used to vary the needle tip length 295 and the needle tip angle 300. A tight tolerance between the needle body diameter 255 of about 0.002 inches (e.g., less than the dilator lumen diameter 250) will provide for the axial alignment of the needle body 252 and the needle tip 18 such that buckling of the needle 12 at the hinge point 20 is not significant, and the spaced dilator 108 will guide the needle 12 into coaxial alignment with the dilator central axis 275.

[0101] Figures 10A to 10DAn embodiment of a hinge point 20 located between the distal end 22 of the guide wire and the needle body 252 is shown. For example, the hinge point 20 or hinge 20 can be formed of an elastic material such as stainless steel, nitinol, or other elastic metal, which has a specified equilibrium shape, such as a 90-degree bend, or preferably a more acute bend. For example, if the hinge point 20 is temporarily straightened into a linear configuration due to a constraining force (such as the constraining force provided by the dilator 108), the hinge 20 will return to its bent shape after the removal of the constraining force. The hinge point 20 or hinge 20 can be formed as an interconnected portion that joins the distal end 22 of the guide wire to the needle body 252. The hinge 20 can be an interconnected portion of the needle body 252 that is joined to the distal end 22 of the guide wire, or the hinge 20 can be a separate region that is joined to both the needle body 252 and the distal end 22 of the guide wire. The hinge 20 can be formed of, for example, nitinol that is joined to a nitinol needle; the needle 12 can be joined or attached to the distal end 22 of the guide wire. The joining process can include various welding, brazing, or soldering methods, or adhesives or mechanical joining methods can be used. Alternatively, a heat treatment method can be used to form the hinge point 20 into an equilibrium shape, for example, the equilibrium shape has a specific kink angle, such as an acute angle.

[0102] The hinge point 20 can be formed by a hinge 20 having a cylindrical cross-section and a hinge diameter 310 that is equal to the guide wire diameter 258 or the needle body diameter 255, as Figure 10A shown. For example, the hinge 20 can be formed of an elastic material (such as nitinol or Elgiloy nonmagnetic alloy) such that it maintains a generally linear shape when housed within the dilator lumen 111, but bends after the hinge 20 is delivered out of the distal tip 110 or distal end 110 of the dilator, thereby forming an equilibrium shape that has (for example): an acute needle-GW angle 315 or bend (in the range of 45 degrees - 140 degrees (including the end values)) between the distal end 22 of the guide wire and the needle body 252, as Figure 10B shown.

[0103] In an alternative embodiment, the hinge point 20 can be formed to have a circular hinge cross-section 320, where the hinge diameter 310 is less than the guide wire diameter 258 or the needle body diameter 255, as Figure 1 shown in OC. The smaller hinge diameter 310 allows the hinge 20 to bend via elastic deformation of the nitinol material, for example, when it travels within the dilator lumen 111 in a generally linear configuration. After the hinge 20 is released from the distal tip 110 of the dilator, the needle body 252 and the distal end 22 of the guide wire form a specified needle-GW angle 315 (in the range of 45 degrees - 140 degrees (including the end values)).

[0104] In another embodiment, the hinge point 20 may be formed by a rectangular hinge 322 having a hinge cross-section 320, as Figure 10D and Figure 10E shown. The hinge 20 may also be formed from an elastic material but has been machined or otherwise shaped into a rectangular shape that may provide benefits over a circular shape. Since the needle body 252 is designed to bend in a specific direction defined by the plane of the guidewire loop segment 14 (e.g., as shown by loop segment 14 substantially in the plane of the paper), the hinge 20 may be formed such that the hinge bending axis 323 is coplanar with the loop segment 14. The hinge height 325 may be much less than the hinge width 330, thereby allowing the hinge 20 to be easily bent while keeping the hinge 20 just below its elastic limit such that the bending remains fully elastic while being confined within the dilator lumen 111. The hinge width 330 may be equal to the guidewire diameter 258 at the distal end 22 of the guidewire and may have a rounded edge with a curvature similar to that of the distal end 22 of the guidewire; the hinge width 330 being greater than the hinge height 325 may provide optimal propulsion of the guidewire 10 transferred to the needle body 252 such that the needle tip 18 can be pushed past the FO 202, as Figure 14A shown. The hinge length 335 may be adjustable to ensure that the hinge 20 remains in an elastic state during its substantially linear configuration within the dilator 108 such that after the hinge 20 is released from the distal tip 110 of the dilator, the hinge 20 will bend, for example, to an acute needle-guidewire angle 315 (in the range of 45 degrees - 140 degrees), thereby causing the needle body 252 to bend sharply relative to the distal end 22 of the guidewire, as Figure 10E shown.

[0105] A longer hinge length 335 distributes the bending deformation over a longer length and thus the hinge point 20 remains more elastic for returning to the equilibrium bent shape after being delivered to the dilator 108 in a straightened shape. The hinge height 325 (which may be less than the guidewire diameter 258) further maintains the hinge point 20 in an elastic state during bending of the hinge point 20. The hinge height 325 together with the hinge width 330 determines the amount of force for folding the needle to an acute angle relative to the distal end 22 of the guidewire after exiting the spaced dilator 108. The hinge 20 may thus be designed to have, for example, a smaller hinge height 325 relative to the guidewire diameter 258 to provide a smaller bending force for folding the needle body 252 than if the hinge 20 were formed from a cylindrical filament having the same diameter as the guidewire diameter 258.

[0106] In another embodiment, as Figures 11A to 11C shown, a tip sheath 340 is placed around the needle tip 18 to provide collinear alignment of the needle body central axis 270 and the dilator central axis 275. As Figure 11AAs shown, the tip sheath 340 is placed around the needle tip 18 and extends slightly distally to the needle tip 285. The tip sheath 340 can be assembled around the needle body 252 via a friction fit to allow the spaced guide wire 10 and the needle to traverse distally within the dilator lumen 111 without buckling and without piercing the needle tip 285 into the dilator lumen wall 342. The tip sheath 340 is formed such that it has a tip sheath outer diameter 345 that provides a sufficient clearance of, for example, 0.003 inches from the dilator lumen diameter 250 (the tip sheath diameter is 0.002 inches - 0.005 inches smaller than the dilator lumen diameter 250) to allow for easy movement together when the tip sheath 340 and the needle body 252 move distally within the dilator lumen 111. The dilator stop 350 can be located at the distal tip 110 of the dilator, which prevents the tip sheath 340 from moving from inside the dilator lumen 111 to an area outside the dilator 108. The dilator stop diameter 355 can be, for example, 0.004 inches smaller than the tip sheath outer diameter 345 (in the range of 0.002 - 0.008 inches, including the end values) to prevent the tip sheath 340 from leaving the dilator lumen 111 over the dilator stop 350. When the needle body 252 and the tip sheath 340 move distally through the dilator lumen 111, the tip sheath 340 will contact the dilator stop 350 and will remain in contact with the dilator stop 350 while the needle body 252, which can be, for example, 0.002 inches smaller than the dilator stop diameter 355 (in the range of 0.001 inches - 0.005 inches, including the end values), can freely pass through the dilator stop 350. The tip sheath 340 can provide a protective covering for the needle tip 18 that prevents the needle tip 18 from piercing into the dilator lumen wall 342, and the tip sheath can also provide a collinear alignment of the needle body central axis 270 with the dilator central axis 275.

[0107] For example, the tip sheath 340 can be formed from a lubricious plastic material such as polytetrafluoroethylene such that it can slide well relative to the dilator lumen wall 342 during passage through the dilator 108. Moreover, the polytetrafluoroethylene surface allows the needle body 252 and the spaced guide wire 10 to pass through the inner surface of the tip sheath 340 after the tip sheath 340 has contacted the dilator stop 350. For example, the tip sheath inner diameter 360 can be 0.002 inches smaller than the guide wire diameter 258 to provide unconstrained movement of the guide wire 10 through the dilator stop 350.

[0108] In yet another embodiment, as Figure 11A described, the tip sheath 340 can be a releasable tip sheath 365 that is formed such that it provides release from the needle body 252 after the releasable tip sheath 365 has contacted the dilator stop 350, as Figure 11B and Figure 11CAs shown in. The releasable tip sheath 365 can be formed such that it has a tip sheath balanced inner diameter 370 that is smaller than the needle body diameter 255 by, for example, approximately 0.002 inches (in the range of 0.001 inches - 0.010 inches smaller). The smaller tip sheath balanced inner diameter 370 can provide a releasable and secure attachment of the releasable tip sheath 365 to the needle body 252 during the distal traverse of the needle body 252 through the dilator lumen 111. The releasable tip sheath 365 can be formed, for example, to have a braided tubular structure or an elastomeric polymer tubular structure that tends to expand in diameter when forced into a shorter tip sheath length 375. After the releasable tip sheath 365 contacts the dilator stop 350, as Figure 11C shown, the releasable tip sheath 365 is forced to compress after contacting the dilator stop 350 and tends to expand in diameter to a releasable tip sheath expanded diameter 380 that has a larger releasable tip sheath expanded diameter than the needle body diameter 255; the expansion of the releasable tip sheath 365 thus allows the needle body 252 and the guide wire 10 to freely pass through the releasable tip sheath lumen 385 and exit from the dilator tip.

[0109] The transseptal guide wire 10 (needle-guide wire or guide wire), dilator 108, and deflectable sheath 100 of the present subject matter can include the structures and configurations as shown in Figure 12 , Figure 13 and Figures 14A - 14F shown; for example, the present subject matter can be used to enter the left atrial chamber from the RA across the FO to perform diagnostic or therapeutic procedures. It should be understood that the present subject matter can also be used to cross the wall of a blood vessel conduit, cross another septum of the heart, or cross the wall / septum of another organ of the body. The guide wire proximal segment 16, guide wire loop segment 14, and guide wire distal end 22 are shown in Figure 12 and have been previously described in Figures 1 - 4 and Figures 7 - 8 shown. The subject matter aims to provide a safe and effective passage of the needle-guide wire 10 of the present subject matter across the FO wall 390 without allowing a sudden bend of the transseptal needle so as not to inadvertently impact or penetrate into the interatrial septum 204 and to prevent the proper formation of the guide wire loop segment 14 in the LA. As shown in Figure 12 , Figure 13 and Figures 14A - 14F shown, the transseptal guide wire 10 can have a hinge point 20 that allows the needle body 252 to suddenly bend and form a needle-guide wire angle 315 with the guide wire distal end 22, such as an acute angle (in the range of 45 degrees - 140 degrees (including the end values)). When the needle body 252 extends out of the dilator 108 and into the LA 208 (see Figures 14A - 14F) Importantly, it is crucial that the needle tip 18 does not impact or penetrate into the interatrial septum 204, thus preventing the ring segment 14 from being properly delivered into the LA 208 as previously described. To assist in identifying the position of the needle tip 18 when delivering it across the interatrial septum 204, a radiopaque marker 395 of the distal guidewire can be located on the needle body 252 adjacent to the needle tip 18. A radiopaque marker 398 of the guidewire hinge can be adjacent to the hinge 20 on the distal end 22 of the guidewire to provide fluoroscopic visualization of the position of the needle body relative to the distal tip of the dilator, which is identified via fluoroscopic visualization of the radiopaque marker 505 at the distal end of the dilator. It should be noted that alternatively or additionally, external markers can be placed at positions outside the patient on the proximal segment 16 of the guidewire and the dilator shaft 109; such external markers can be used to determine the axial positioning of the guidewire needle tip 18 relative to the distal end 110 of the dilator during the FO bulge and during the forward movement of the needle-guidewire 10 and the dilator 108 across the FO.

[0110] As Figure 12 shown, the transseptal guidewire 10 can be formed of a metal such as stainless steel, nitinol, or other materials commonly used to form standard guidewires in the medical device industry. The needle length 280 can be, for example, about 5 mm (within the range of 3 mm - 15 mm, including the end values), and is designed to have a sufficient needle length 280 to penetrate through the 2 mm - 3 mm thick wall 390 of the FO 202 and still have an axial length of at least 1 mm - 2 mm of the transseptal needle extending within the dilator nose 400 (see Figure 13 and Figure 14A ), to maintain the axial alignment of the needle with the dilator nose 400 without bending at the hinge point 20, as will be further described later in Figure 14B and in this specification. A shorter needle length 280 (still within the needle length range) may require multiple short forward movements of the needle (e.g., 2 - 3 forward movements of 1 mm - 3 mm axial movement) to cross the FO wall 390, followed by multiple similar forward movements of the dilator nose 400, which provides axial alignment support for the needle. A longer needle length 280 (still within the needle length range) will require a longer dilator nose length 415 (see Figure 13 and Figures 14A - 14D ) to ensure that the needle does not penetrate into the interatrial septum 204 after leaving the distal end 110 of the dilator and the needle-guidewire 10 bends at the hinge point 20; such a longer needle length 280 can also cause the needle tip 18 to impact the LA sidewall 405 during the deployment of the needle tip 18 from the distal tip 110 or the distal end 110 of the dilator (see Figure 14C ). The needle length 280 and the dilator nose length 415 used in this subject matter are designed to deliver the needle 12 into the central region of the LA before delivering the entire needle-guidewire 10 into the LA.

[0111] As Figure 13 and Figure 14A shown in Figure 4 C), the expander distal region 245 of embodiments of the present subject matter can have an expander distal segment 106 that includes an expander bevel segment 410 and an expander nose 400. The outer cylindrical surface of the expander nose 400 contacts the outer surface of the bevel segment 410 at the expander inflection point 412. The expander nose 400 extends from the bevel segment 410 to the expander distal tip 110 and has a thin-walled cylindrical shape that easily extends through the FO wall 390 and does not significantly expand the FO 202 due to the low-profile thin-walled expander nose 400. The expander nose 400 can thus guide the needle of the transseptal guidewire 10 through the FO and into the chamber of the LA 208 without allowing the needle to suddenly bend and potentially impact or penetrate into the atrial septum 204. The expander nose length 415 can be, for example, 9 mm (in the range of 5 mm - 18 mm); a shorter expander nose length 415 may not guide the needle past the FO wall 390 into the LA 208, allowing the hinge point 20 of the needle to bend into an acute angle and potentially impact or penetrate into the atrial septum 204. A longer expander nose length 415 may not provide support to guide the needle perpendicular to the plane of the FO; additionally, such a longer nose length 415 may extend further into the LA 208 than desired, potentially guiding the needle tip 18 to be delivered into the LA 208 and impact the side wall 405 of the LA 208 (see

[0112] The expander nose 400 can be formed from a thin-walled hypotube made of stainless steel, nitinol, or other metal, or it can be formed from a polymeric material such as polyimide, polyethylene terephthalate, or other polymers with a relatively high tensile strength and that can be formed into a thin-walled (e.g., a wall thickness in the range of 0.0015 inches - 0.005 inches (including the end values), such as 0.003 inches) tube, where the expander lumen diameter 250 can provide a passage with a tight tolerance (e.g., a clearance in the range of 0.002 inches - 0.004 inches (including the end values)) for a transseptal guidewire 10 or a standard guidewire. Thus, the expander nose 400 has an outer diameter similar to the guidewire fixed diameter 258 to provide an easy transition passage over the FO 202 for the expander nose 400. The expander nose 400 can extend within the expander bevel segment 410 and be permanently attached to the expander bevel segment via an adhesive, insert molding into the polymeric material of the expander 108, thermal bonding, solvent bonding, or other bonding methods. The expander bevel segment 410 provides a support and stable base to the nose support region 420 of the thin-walled tube forming the expander nose 400, as Figure 13As shown. The dilator bevel section 410 extends proximally from the dilator nose 400 with a small diameter equal to the diameter of the dilator nose 400 in a conical manner to a dilator shoulder 425 with a larger diameter equal to the dilator fixed diameter 118, and this dilator fixed diameter can pass through the deflectable sheath 100 (for example, the sheath diameter is about 8.5Fr, within the range of 6Fr to over 20Fr) with minimal friction and full lateral support from the deflectable sheath, as previously described. The dilator bevel section 410 can be formed continuously with the dilator nose 400 from the same material as the dilator nose 400 by: forming these parts of the dilator with a material suitable for the functional aspects of the smooth dilator bevel section 410 and the thin-walled high compressive strength dilator nose 400, and these parts can be advanced via a guide wire without collapsing.

[0113] The dilator 108 can have a cylindrical dilator alignment zone 430 with a dilator fixed diameter 118 having an axial distance of 5 mm extending proximally from the dilator shoulder 425 (within the range of 3 mm to the entire dilator axis 109 proximal to the dilator shoulder). The dilator alignment zone 430 provides axial alignment of the dilator central axis 275 with the sheath central axis 435 in the sheath straight zone 440, as Figure 14A As shown. The purpose of the dilator axial alignment zone 430 is to provide controlled directionality to the dilator axial alignment zone 430 and the dilator nose 400 such that the dilator alignment zone 430 and the dilator nose 400 are guided perpendicular to the FO during the bulge 525 and prior to using the needle-guide wire 10 to penetrate the FO 202 via the deflectable sheath 100. The axial alignment zone 430 enhances the ability of the needle to hold the desired target site within the FO 202 without sliding along the surface of the FO, thereby causing angled spaced punctures.

[0114] The septal dilator 108 of the present subject matter can have a dilator waist 445 located proximal to the dilator alignment zone 430 and extending approximately 20 mm (within the range of 5 mm - 50 mm (including the end values)) to extend over the entire axial length of the sheath bend region 530 (see Figure 14A)。The expander waist 445 provides a region of the expander shaft 109 that is more flexible than the remainder of the expander shaft 109 proximal to the expander shoulder 425, yet still has sufficient pushability or expander shaft 109 compression characteristics. The expander waist 445 can have an expander waist diameter 500, for example, that is 50% of the diameter of the expander fixed diameter 118 (in the range of 30% - 95% inclusive of the end values). The waist 445 can also be formed of, for example, a polymer having a lower hardness than the remainder of the expander shaft 109 such that the expander waist diameter 500 can be consistent and equal to the expander fixed diameter 118, but with greater flexibility and maintaining sufficient pushability.

[0115] Place a radiopaque marker, such as the distal expander radiopaque marker 505, near the distal expander tip 110. The distal expander radiopaque RO marker 505 allows the physician to visualize the position of the distal expander tip 110 relative to the distal guidewire RO marker 395 to ensure that the needle tip 18 does not protrude from the distal expander tip 110 when the distal expander tip 110 is positioned against the FO to form the bulge 525 of the FO, as previously described.

[0116] The expander shoulder radiopaque marker 122 is located on the expander shoulder 425 adjacent to the expander bevel section 410. The expander shoulder radiopaque marker 122 can be aligned or overlapped (under fluoroscopy) with the distal sheath radiopaque marker 123 such that they overlap each other in the axial direction of the sheath 100 and the expander 108. The physician uses such alignment during the delivery of the expander 108 and the sheath 100 through the vasculature of the body via a standard guidewire and into the RA. The physician also uses this alignment to ensure a smooth transition of the sheath 100 and the expander 108 and a flush diameter fit on the transseptal guidewire 10 of the present subject when the sheath 100 and the expander 108 are advanced together past the FO wall 390.

[0117] The dilator proximal port 515 located on the dilator manifold 520 can be used to provide an entry for a standard guide wire and also provide access for the transseptal guide wire 10 of the present subject matter. It should also be noted that the presence of the dilator nose 400 on the distal dilator segment 106 provides an additional benefit for the use of the dilator proximal port 515 in the transseptal dilator 108 of the present invention. In the case where the dilator nose 400 is positioned beyond the FO, the transseptal guide wire 10 can be removed from the dilator 108, and the dilator lumen 111 can be used to provide pressure measurement within the LA 208. The dilator proximal port 515 can be attached via a suitable pressure transducer tube to a pressure transducer located outside the patient's body in order to obtain a pressure reading in the LA 208 before or after a treatment procedure. The transseptal guide wire 10 of the present subject matter can be effectively re-introduced back into the dilator lumen 111 of the present subject matter as needed to complete or resume a treatment procedure without wire exchange; retracting the needle-guide wire 10 into the introducer will permit easy re-introduction of the needle-guide wire 10.

[0118] The transseptal guide wire 10 and dilator 108 of the present subject matter are shown in Figure 14A which the transseptal guide wire and the dilator are contained within the sheath distal segment 107 of the deflectable sheath 100, the sheath distal segment being located within the RA 206 and positioned to deliver the bulge 525 onto the FO 202 via the dilator nose 400. As previously described, the dilator 108 and the deflectable sheath 100 have been delivered to the site of the RA 206 via a standard guide wire, and the standard guide wire has been replaced by the transseptal guide wire 10 of the present subject matter. The deflectable sheath 100 was initially guided adjacent to the FO using ultrasound or other imaging modalities. Figures 14A - 14F An embodiment of a continuous use method for placing the transseptal guide wire 10 across the FO and into the LA is described.

[0119] As Figure 14AAs shown, adjacent to the proximal end 102 of the sheath, the sheath handle 104 has been activated to form an elbow in the sheath bending region 530, so that the sheath straight region 440 is aligned perpendicular to the plane of the FO 202. The actuator 212 located on the sheath handle 104 can be used to move the dilator distally or proximally relative to the deflectable sheath 100 in a controlled manner. The distal end 124 of the sheath is positioned by ultrasonic observation of the radiopaque mark 123 on the distal sheath, such that the distal end 124 of the sheath is approximately 5 mm from the FO 202. As observed by fluoroscopy, the needle tip 18 has been retracted into the dilator nose 400 during the bulge 525, which shows that the distal radiopaque mark 395 of the GW overlaps (or is slightly proximal in the axial direction) with the distal radiopaque mark 505 of the dilator, to ensure that the needle tip 18 does not protrude from the distal end or the distal tip 110 of the dilator. The dilator alignment region is in full sliding and supportive contact with the sheath straight region 440, such that the dilator central axis 275 in the region of the dilator nose 400 is coaxial with the sheath central axis 435 in the region of the sheath straight region 440.

[0120] The dilator alignment region is firmly held by the sheath straight region 440, such that the deflectable sheath 100 can guide the dilator nose 400 perpendicular to the FO, as Figure 14A shown. The dilator waist 445 is located within the sheath bending region, such that the enhanced flexibility of the dilator waist 445 does not tend to straighten the sheath bending region 530 during the forward movement of the dilator 108 within the sheath 100. The flexible dilator waist 445 reduces the tendency of the dilator 108 to form a straight axial configuration over its entire axial length, but can be easily held in a bent configuration that matches the elbow of the sheath bending region 530 and provides a perpendicular alignment of the dilator alignment zone 430 and the dilator nose 400 to the plane of the FO 202.

[0121] Once it is confirmed that the bulge 525 has appeared in the appropriate position in the FO 202, the needle can be advanced forward over the FO wall 390, as Figure 14B shown. A portion of the needle distal to the hinge point 20 is received within the dilator nose 400 to provide axial alignment of the needle body central axis 270 and the dilator central axis 275 in the region of the nose 400, such that the plane perpendicular to the FO 202 guides the needle body 252, thereby preventing angled puncture of the needle and thus providing resistance to the forward movement of the needle over the FO 202. The radiopaque mark 398 of the guidewire hinge is observed to be positioned proximal to the distal radiopaque mark 505 of the dilator under fluoroscopy.

[0122] When the needle tip 18 is advanced forward over the FO wall 390 (see Figure 14C) In the case of , the dilator 108 can be advanced forward via the transseptal guidewire 10 while keeping the transseptal guidewire 10 in a fixed position. The distal tip 110 of the dilator extends distally from the tip 18 of the needle, as confirmed by the position of the distal radiopaque RO mark of the dilator being distal to the distal guidewire RO mark 395 and extending through the FO wall 390 by a nasal penetration distance 535 equal to or greater than the needle length 280 under ultrasound and fluoroscopy. For a 3 mm FO wall thickness 540, for example, a 9 mm dilator nose 400 can be advanced forward via the transseptal guidewire 10 until the dilator inflection point 412 makes initial contact with the FO, thereby providing a 6 mm nasal penetration or protrusion distance 535 into the LA, for example, to ensure that a needle with a 5 mm needle length (for example) cannot inadvertently bend at the hinge point 20 and impact or penetrate into the interatrial septum 204.

[0123] As Figure 14D shown, the needle-guidewire 10 is advanced through the dilator nose 400, thereby placing the needle into the central region of the chamber of the LA 208 and allowing full deployment of the needle, and allowing hinge bending to form an acute needle-guidewire angle 315 with the distal end 22 of the guidewire, preferably between 50 degrees and 80 degrees, but having a range of 45 degrees to 140 degrees. The nasal protrusion distance 535 into the LA 208 being equal to or greater than the needle length prevents the needle from impacting or penetrating into the interatrial septum 204.

[0124] The radiopaque mark 398 of the guidewire hinge has been advanced to a position distal to the distal radiopaque mark 505 of the dilator, as confirmed under fluoroscopy, and indicates that the needle 12 extends distally from the distal tip 110 of the dilator.

[0125] The transseptal guidewire 10 can be further advanced distally within the dilator lumen 111 such that a loop segment 14 is formed in the LA 208, as Figure 14E shown. The loop segment 14 can be composed of multiple loops of different sizes and configurations as previously described and has an outer diameter of approximately 30 mm, within the range of 25 mm to 40 mm. The loop segment 14 can contact the LA 208 sidewall 405 and the interatrial septum 204, thereby contributing to guidewire position stability. The presence of the guidewire loop segment 14 within the LA provides position stability to advance the dilator bevel segment 410 and the deflectable sheath 100 via the needle-guidewire 10 and over the FO 202.

[0126] The distal end 124 of the sheath is aligned with the dilator shoulder 425, as confirmed by the overlap of the distal sheath RO mark 123 and the dilator shoulder RO mark 122, as Figure 14F shown. Then, as Figure 14F shown, the dilator 108 and the deflectable sheath 100 are advanced forward together over the FO, thereby placing a sheath protrusion distance 545 of approximately 3 mm, for example, into the LA.

[0127] Then, after removing the dilator 108 from the sheath 100, the deflectable sheath 100 can be used to deliver a diagnostic or therapeutic device across the FO 202 via the transseptal wire 10. Alternatively, both the deflectable sheath 100 and the dilator 108 can be removed, leaving the transseptal wire 10 across the FO for delivering a diagnostic or therapeutic device across the FO.

[0128] As Figure 15 shown, sometimes, the FO wall thickness 540 can be greater than 2 mm - 3 mm for some patients, reaching an FO wall thickness 540 of 5 mm or greater, and thus changing the steps of the method of use for advancing the transseptal wire 10 across the FO as Figure 14D shown. In the case of an overly thickened FO wall 390, the physician may desire to advance the dilator inflection point 412 into a portion of the FO wall 390, thereby increasing the amount of the dilator nose projection distance 535 extending into the LA. The increase in the dilator nose projection length allows a needle having a needle length equal to or less than the nose projection length to be safely advanced into the LA 208 without the problem that the tip 18 may inadvertently impact or penetrate the atrial septum 204. Multiple advancement steps of several millimeters can be performed by advancing the transseptal wire 10 and then immediately advancing the dilator 108 until the FO wall 390 has been successfully traversed and the wire loop segment 14 has been successfully delivered into the LA. The remaining steps of the method of use are the same as those previously described.

[0129] Endnotes and examples :

[0130] The foregoing detailed description includes reference to the accompanying drawings, which form a part of the detailed description. The detailed description should be read in reference to the accompanying drawings. The drawings illustrate, by way of example, specific embodiments in which the subject matter may be practiced. These embodiments are also referred to herein as "examples."

[0131] The detailed description is intended to be illustrative and not restrictive. For example, the above examples (or one or more features or components thereof) may be used in combination with each other. For example, other embodiments may be used by those skilled in the art after reviewing the detailed description.

[0132] The scope of use of the example can be expanded for other uses, such as non-transseptal procedures, both vascular and avascular lumen organ structures. Also, various features or components have been grouped together to simplify the disclosure. This should not be construed as wishing that the disclosed features not claimed are essential to any claim. Rather, the inventive subject matter may exist with less than all of the features of a particular disclosed embodiment. Accordingly, the following claim examples are hereby incorporated into the detailed description, where each example stands on its own as a separate embodiment:

[0133] In Example 1, a method of treating a patient may include: advancing distally a dilator located within the lumen of a sheath relative to the sheath, including applying a bulging force to a septal wall associated with the oval fossa of the heart using a dilator nose located at a distal end portion of the dilator; advancing distally a tip of a needle attached to a guide wire and located within the lumen of the dilator relative to the dilator, including piercing the septal wall associated with the oval fossa; advancing the dilator distally via the guide wire while maintaining the guide wire and the sheath in fixed positions, including extending a distal end of the dilator nose beyond the septal wall associated with the oval fossa by a distance equal to or greater than the length of the needle; and advancing the guide wire distally through the dilator nose, including allowing the needle to be deployed in a central region of the left atrium of the heart.

[0134] In Example 2, the method of Example 1 may optionally be configured such that advancing the dilator distally relative to the sheath includes manipulating an actuator located on or adjacent to a handle of the sheath.

[0135] In Example 3, the method of either Example 1 or Example 2 may optionally be configured such that when advancing the dilator distally relative to the sheath, the tip of the needle is positioned within the dilator nose.

[0136] In Example 4, the method of any one or any combination of Examples 1 to 3 may optionally be configured such that when advancing the tip of the needle distally relative to the dilator, a position of a hinge connecting a distal end of the guide wire and a proximal end of the needle is maintained proximal to a distal end of the dilator nose.

[0137] In Example 5, the method of Example 4 may optionally be configured such that allowing the needle to be deployed in the central region of the left atrium includes allowing the hinge to bend and form an acute angle between the distal end of the guide wire and the proximal end of the needle.

[0138] In Example 6, the method of either Example 4 or Example 5 may optionally be configured such that allowing the needle to be deployed in the central region of the left atrium includes: visualizing a position of the hinge relative to a distal end of the dilator nose; and confirming that the hinge is positioned distal to the distal end of the dilator nose.

[0139] In Example 7, the method of any one or any combination of Examples 1 to 6 may optionally further include: maintaining coaxial alignment between the dilator and the sheath by engaging an alignment region of the dilator proximal to the dilator nose with an inner lumen wall of the sheath.

[0140] In Example 8, the method of any one of Examples 1 to 7 or any combination thereof may optionally be configured such that extending the distal end of the dilator nose beyond the septal wall associated with the fossa ovalis by a distance equal to or greater than the length of the needle includes: preventing the needle from impinging on the left side dimension of the atrial septum of the heart.

[0141] In Example 9, the method of any one of Examples 1 to 8 or any combination thereof may optionally be configured such that advancing the guidewire distally through the dilator nose includes: allowing a loop segment of the guidewire to form in the left atrium.

[0142] In Example 10, the method of Example 9 may optionally be configured such that allowing a loop segment of the guidewire to form in the left atrium includes: engaging a portion of the guidewire loop segment with the left atrial wall or the left side of the atrial septum.

[0143] In Example 11, the method of either Example 9 or 10 may optionally further include advancing the dilator and sheath distally via the guidewire and past the septal wall associated with the fossa ovalis, including extending the dilator bevel segment proximal to the dilator nose, followed by the dilator shoulder proximal to the dilator bevel segment, and the distal end of the sheath into the left atrium.

[0144] In Example 12, the method of Example 11 may optionally further include removing one or both of the dilator and sheath from the patient and delivering a diagnostic or therapeutic device via the guidewire and past the septal wall associated with the fossa ovalis.

[0145] In Example 13, the method of any one of Examples 1 - 12 or any combination thereof may optionally further include, before advancing the guidewire distally through the dilator nose, retracting the guidewire proximally and using the lumen of the dilator to measure the pressure within the left atrium.

[0146] In Example 14, anatomic wall crossing system may include a dilator extending from a proximal end portion to a distal end portion and including a lumen therethrough. The distal end portion may include a dilator nose and a dilator bevel segment. The dilator nose may have a first outer diameter and a length of about 5 mm - 18 mm (including the end values). The dilator bevel segment may extend proximal to the dilator nose and may taper from a second outer diameter greater than the first outer diameter to the first outer diameter.

[0147] In Example 15, the wall crossing system of Example 14 may optionally be configured such that the dilator nose includes a cylindrical cross - sectional shape having a wall thickness of about 0.0015 inches - 0.005 inches (including the end values).

[0148] In Example 16, the wall-crossing system of Example 15 may optionally be configured such that the dilator nose is formed of a thin-walled hypotube.

[0149] In Example 17, the wall-crossing system of any one of Examples 14-16 or any combination may optionally be configured such that the dilator further includes a dilator alignment zone that extends proximal to the dilator bevel segment and has a substantially uniform outer diameter.

[0150] In Example 18, the wall-crossing system of Example 17 may optionally be configured such that the dilator further includes a dilator waist that extends proximal to the dilator alignment zone and has greater longitudinal flexibility than the dilator alignment zone.

[0151] In Example 19, the wall-crossing system of Example 18 may optionally be configured such that the dilator waist has a length of about 5 mm - 50 mm (including the end values).

[0152] In Example 20, the wall-crossing system of any one of Examples 18 or 19 may optionally be configured such that the dilator waist has an outer diameter that is 30% - 90% (including the end values) of the outer diameter of the dilator alignment zone.

[0153] In Example 21, the wall-crossing system of any one of Examples 18-20 or any combination may optionally be configured such that the dilator waist is formed of a polymer having a lower hardness than the polymer of the dilator alignment zone.

[0154] In Example 22, the wall-crossing system of any one of Examples 14-21 or any combination may optionally further include a guide wire that can be delivered within the lumen of the dilator and extends from the proximal end to the distal end, and the distal end is attached to a puncture needle having a needle body and a needle tip.

[0155] In Example 23, the wall-crossing system of Example 22 may optionally be configured such that an intermediate portion of the guide wire includes at least one loop segment.

[0156] In Example 24, the wall-crossing system of any one of Examples 22 or 23 may optionally be configured such that the puncture needle has a length of 3 mm - 20 mm (including the end values).

[0157] In Example 25, the wall-crossing system of any one of Examples 22-24 or any combination may optionally be configured such that the needle body has a needle body diameter that is 0.001 inches - 0.004 inches (including the end values) smaller than the lumen of the dilator to facilitate coaxial alignment of the needle body axis and the dilator axis.

[0158] In Example 26, the wall-crossing system of any one of Examples 22-25 or any combination thereof may optionally be configured such that the distal end of the guide wire is attached to the proximal end of the puncture needle at the hinge.

[0159] In Example 27, the wall-crossing system of Example 26 may optionally be configured such that the hinge includes a shape memory material and forms an angle of 45 degrees to 140 degrees (including the end values) between the distal end of the guide wire and the proximal end of the puncture needle when unconstrained.

[0160] In Example 28, the wall-crossing system of any one of Examples 26 or 27 may optionally be configured such that the hinge includes a cylindrical cross-sectional shape having a diameter smaller than the diameters of the guide wire and the needle body.

[0161] In Example 29, the wall-crossing system of any one of Examples 26 or 27 may optionally be configured such that the hinge includes a rectangular cross-sectional shape and is configured to bend in a direction defined by the plane of at least one loop segment.

[0162] In Example 30, the wall-crossing system of any one of Examples 22-29 or any combination thereof may optionally further include a tip sheath placed around the puncture needle to facilitate coaxial alignment of the needle body axis and the dilator axis.

[0163] In Example 31, the wall-crossing system of Example 30 may optionally be configured such that the dilator includes a dilator stop configured to inhibit distal movement of the tip sheath from a position within the lumen of the dilator to a position outside the lumen of the dilator.

[0164] In Example 32, the wall-crossing system of Example 31 may optionally be configured such that the tip sheath is configured to expand in diameter when compressed, thereby allowing release of the tip sheath from the puncture needle after contact with the dilator stop.

[0165] In Example 33, the wall-crossing system of any one of Examples 14-32 or any combination thereof may optionally further include a deflectable sheath.

[0166] In Example 34, the wall-crossing system of Example 33 may optionally be configured such that the proximal end portion of the dilator is configured to engage an actuator incorporated into the handle of the deflectable sheath. The actuator may be configured to control distal and proximal advancement of the dilator relative to the deflectable sheath.

[0167] Certain terms used throughout this patent document refer to particular features or components. As will be appreciated by those skilled in the art or as will become apparent, the same feature or component may be referred to by different names by different individuals. This patent document is not intended to distinguish components or features that have different names but not different functions.

[0168] For the terms defined below, certain definitions will apply unless a different definition is given elsewhere in this patent document. The terms "a", "an", and "the" are used to include one or more than one, regardless of any other instances or uses of "at least one" or "one or more". The term "or" is used to refer to a non-exclusive or, such that "A or B" includes "A but not B", "B but not A", and "A and B". Unless explicitly indicated, it is assumed that all numerical values are modified by the term "about". The term "about" generally refers to a range of numbers that a person skilled in the art would consider equivalent to the recited value (i.e., having the same function or result). In many instances, the term "about" may include numbers that are rounded to the nearest significant figure. A numerical range recited by endpoints includes all values and sub-ranges within that range or bounding that range (e.g., 1 to 4 includes 1, 1.5, 1.75, 2, 2.3, 2.6, 2.9, etc., as well as 1 to 1.5, 1 to 2, 1 to 3, 2 to 3.5, 2 to 4, 3 to 4, etc.). The terms "patient" and "subject" are intended to include mammals, such as for human or veterinary applications. The terms "distal" and "proximal" are used to refer to a position or direction relative to a treating clinician. "Distal" and "distally" refer to a position away from the treating clinician or in a direction away from the treating clinician. "Proximal" and "proximally" refer to a position close to the treating clinician or in a direction toward the treating clinician.

[0169] The scope of the subject matter should be determined with reference to the appended claims and the full scope of equivalents to which such claims are entitled. In the appended claims, the terms "including" and "in which" are used as the plain English equivalents of the corresponding terms "comprising" and "wherein". Also, in the appended claims, the terms "including" and "comprising" are open-ended; i.e., a system, apparatus, or method that includes features or components other than those recited after such term in the claim is still considered to fall within the scope of that claim. Additionally, in the appended claims, the terms "first", "second", "third", etc. are used only as labels and are not intended to impose numerical requirements on their objects.

[0170] A summary is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It should be understood that the summary will not be used to interpret or limit the scope or meaning of the claims.

Claims

1. An anatomical wall crossing system, the anatomical wall crossing system comprising: A dilator extending from a proximal end portion having a first outer diameter to a distal end portion and including a lumen therethrough, the distal end portion including a dilator distal tip, a dilator nose, a dilator bevel section, a dilator shoulder, a dilator alignment zone, and a dilator waist, The dilator nose having a cylindrical outer surface and extending within and attached to the dilator bevel section, the dilator nose having a second outer diameter extending from the dilator bevel section to the dilator distal tip, The dilator bevel section extending proximally of the dilator nose and tapering from the dilator shoulder to the second outer diameter of the dilator nose, the dilator alignment zone having a uniform outer diameter and extending proximally from the dilator shoulder, the dilator bevel section having a third outer diameter at the proximal end of the dilator bevel section, the third outer diameter being equal to the first outer diameter and greater than the second outer diameter, and The dilator waist extending proximally of the dilator alignment zone, the dilator waist having a greater longitudinal flexibility than the dilator alignment zone and having an outer diameter that is 30% to 95%, including the end values, of the third outer diameter of the dilator alignment zone, A guide wire capable of being delivered within the lumen of the dilator and extending from a proximal end to a distal end, the distal end attached to a puncture needle having a needle body and a needle tip, the needle tip configured to extend through the dilator nose and extend beyond the dilator nose, and A tip sheath placed around the puncture needle to facilitate coaxial alignment of the needle body axis with the dilator axis, Wherein a distal radiopaque marker is placed near the dilator distal tip, and a shoulder radiopaque marker is located on the dilator shoulder, Wherein the length of the dilator nose is configured to extend through the patient's fossa ovalis and beyond the fossa ovalis by a nose penetration distance into the patient's left atrium, The nose penetration distance being equal to or greater than the needle length of the puncture needle, Wherein the dilator includes a dilator stop configured to inhibit distal movement of the tip sheath from a position within the lumen of the dilator to a position outside the lumen of the dilator, and Wherein the tip sheath is configured to expand in diameter when compressed after contacting the dilator stop to release the puncture needle.

2. The anatomical wall crossing system according to claim 1, wherein the dilator nose includes a cylindrical cross-sectional shape having a wall thickness of 0.0015 inches to 0.005 inches, including the end values.

3. The anatomical wall crossing system according to claim 2, wherein the dilator nose is formed of a thin-walled hypotube.

4. The anatomical wall crossing system according to claim 1, wherein the dilator waist extends proximally of the dilator alignment zone and is configured to extend through the entire axial length of the sheath bend region of the sheath.

5. The trans-anatomical wall crossing system according to claim 4, wherein the expander waist has a length of 5 mm to 50 mm, including the end values.

6. The trans-anatomical wall crossing system according to claim 4, wherein the expander waist has an outer diameter that is 50% of the third outer diameter of the expander alignment zone.

7. The trans-anatomical wall crossing system according to claim 4, wherein the expander waist is formed of a polymer having a lower hardness than the polymer of the expander alignment zone.

8. The trans-anatomical wall crossing system according to claim 1, wherein an intermediate portion of the guide wire includes at least one loop segment.

9. The trans-anatomical wall crossing system according to claim 1, wherein the puncture needle has a length of 3 mm to 20 mm, including the end values.

10. The trans-anatomical wall crossing system according to claim 1, wherein the needle body has a needle body diameter that is 0.001 inches to 0.004 inches, including the end values, smaller than the inner lumen of the expander to facilitate coaxial alignment of the needle body axis and the expander axis.

11. The trans-anatomical wall crossing system according to claim 1, wherein the distal end of the guide wire is attached to the proximal end of the puncture needle at a hinge.

12. The trans-anatomical wall crossing system according to claim 11, wherein the hinge includes a shape memory material and forms an angle of 45 degrees to 140 degrees, including the end values, between the distal end of the guide wire and the proximal end of the puncture needle when unconstrained.

13. The trans-anatomical wall crossing system according to claim 11, wherein the hinge includes a cylindrical cross-sectional shape having a diameter smaller than the diameters of the guide wire and the needle body.

14. The trans-anatomical wall crossing system according to claim 11, the guide wire includes a guide wire loop segment configured to form at least one loop segment when the guide wire loop segment extends into the left atrium of the patient, wherein the hinge includes a rectangular cross-sectional shape and is configured to bend in a direction defined by the plane of the at least one loop segment.

15. The trans-anatomical wall crossing system according to claim 1, the wall crossing system further includes a deflectable sheath.

16. The trans-anatomical wall crossing system according to claim 15, wherein the proximal end portion of the expander is configured to engage an actuator incorporated into a handle of the deflectable sheath, the actuator being configured to control distal and proximal advancement of the expander relative to the deflectable sheath.

17. A trans-anatomical wall crossing system, comprising: an expander extending from a proximal end portion having a first outer diameter to a distal end portion and including an inner lumen therethrough, the distal end portion including an expander distal tip, an expander nose, an expander bevel segment, an expander shoulder, an expander alignment zone, and an expander waist, the expander nose having a second outer diameter and extending from the bevel segment to the expander distal tip, the length of the expander nose being configured to extend through the patient's oval fossa and beyond the oval fossa by a nose penetration distance into the patient's left atrium, The dilator bevel segment extends proximally to the dilator nose and tapers from the dilator shoulder to the second outer diameter of the dilator nose. The dilator alignment zone has a consistent outer diameter and extends proximally from the dilator shoulder. The dilator bevel segment has a third outer diameter at the proximal end of the dilator bevel segment, the third outer diameter being equal to the first outer diameter and greater than the second outer diameter. The dilator waist extends proximally to the dilator alignment zone. The dilator waist has a greater longitudinal flexibility than the dilator alignment zone and has an outer diameter that is 30% to 95%, inclusive of the end values, of the third outer diameter of the dilator alignment zone. A guide wire that can be delivered within the lumen of the dilator and extends from a proximal end to a distal end. The distal end is attached to a puncture needle having a needle body and a needle tip. The needle tip is configured to extend through the dilator nose and extend beyond the dilator nose. The puncture needle has a needle length and the nose penetration distance is equal to or greater than the needle length. A tip sheath that is placed around the puncture needle to facilitate coaxial alignment of the needle body axis and the dilator axis. Wherein, the dilator includes a dilator stop configured to inhibit the distal movement of the tip sheath from a position within the lumen of the dilator to a position outside the lumen of the dilator. Wherein, the tip sheath is configured to expand in diameter when compressed after contacting the dilator stop to release the puncture needle.

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