Shunt device

Abstract

The shunt device is operable between a collapsed configuration and a shunt configuration. The shunt device comprises a shunt frame assembly having a first anchor and a second anchor configured to radially expand from the collapsed configuration to the shunt configuration. The second anchor defines a proximal opening of the shunt device in the shunt configuration, and the first anchor and the second anchor define a common central axis. The shunt device further comprises a flow director extending distally from the shunt frame assembly and defining a fluid pathway and a distal opening at one end of the fluid pathway. The flow director is configured to redirect at least a portion of the fluid flowing through the fluid pathway such that at least a portion of the fluid is discharged through the distal opening in a fluid direction transverse to the central axis.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 435,613, filed December 28, 2022, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to shunt devices, and more particularly to shunt devices useful in the treatment of pulmonary arterial hypertension. [Background technology]

[0003] Pulmonary hypertension (PH) is a disease characterized by persistently increased pulmonary artery pressure. Generally, patients with a mean pulmonary artery pressure of 25 mmHg or higher are considered to have or have symptoms of PH. It is estimated that up to 50 to 70 million people worldwide, or approximately 1% of the total population, suffer from PH. PH is classified into five groups, with group 2 being the most common form of PH, which is PH due to left heart disease. Left heart disease can include heart failure (both with preserved and reduced ejection fraction) and valvular disorders that prevent the heart from properly pumping blood out of the heart. These problems can cause blood to back up in the left atrium and subsequently in the lungs, increasing pulmonary pressure.

[0004] Shunts can be used to treat PH and other conditions, including, but not limited to, heart failure, hypertension, renal failure, volume overload, hypertrophic cardiomyopathy, valvular regurgitation, and numerous congenital disorders. Shunts function as holes or small passageways that allow fluid to move from one part of a patient's body (e.g., the pulmonary artery) to another. The effectiveness and safety of a shunt in its intended use depend primarily on characteristics such as accurate shunt placement, stable shunt immobilization, shunt durability, minimization of potential areas of flow stagnation, ease of deployment, and adjustability over time. Therefore, shunt design and application must continually be improved and refined to achieve shunts that provide safe and effective treatment while also allowing for ease of use and cost reduction. Summary of the Invention

[0005] According to a first aspect, a shunt device is operable between a collapsed configuration and a shunt configuration. The shunt device comprises a shunt frame assembly having a first anchor and a second anchor configured to radially expand from the collapsed configuration to the shunt configuration. The second anchor defines a proximal opening of the shunt device in the shunt configuration, and the first anchor and the second anchor define a common central axis. The shunt device further comprises a flow director extending distally from the shunt frame assembly and defining a fluid pathway and a distal opening at one end of the fluid pathway. The flow director is configured to redirect at least a portion of the fluid flowing through the fluid pathway such that at least a portion of the fluid is discharged through the distal opening in a fluid direction transverse to the central axis. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is an anatomical diagram of a human subject showing the right pulmonary artery and its location relative to other anatomical features. [Figure 2] FIG. 1 is a perspective view of an exemplary shunt device in a shunt configuration. [Figure 3]1 is a cross-sectional view of a shunt device when implanted in a human subject in a shunt configuration. [Figure 4] FIG. 1 shows the resilient body of the shunt device in a longitudinally flattened position. [Figure 5] FIG. 1A is a schematic diagram illustrating a cross-sectional view of a shunt device in a collapsed configuration. [Figure 6] 1A-1C are diagrams illustrating the delivery steps of an exemplary method for implanting a shunt device. [Figure 7] FIG. 2 shows a schematic diagram of the first stage of the first mooring step of the method. [Figure 8] FIG. 2 shows a schematic diagram of the second stage of the first mooring step. [Figure 9] FIG. 2 shows a schematic diagram of a second mooring step of the method. [Figure 10] FIG. 1 illustrates another exemplary shunt device. DETAILED DESCRIPTION OF THE INVENTION

[0007] FIG. 1 is an anatomical diagram of a human subject showing the right pulmonary artery 10 and its location relative to other anatomical features. The right pulmonary artery 10 carries deoxygenated blood from the heart 12 to the right lung so the blood can acquire oxygen and be rid of waste products such as carbon dioxide. As shown in FIG. 1, a segment of the right pulmonary artery 10 extends adjacent to the inferior side of the azygos vein 14, which receives deoxygenated blood from the intercostal veins 20 and deposits the deoxygenated blood in the superior vena cava 24. The vena cava 24 then transports the deoxygenated blood to the right atrium of the heart 12.

[0008] Pressure within the right pulmonary artery 10 can be relieved by diverting blood therefrom to another location. Directly diverting high-pressure blood from the right pulmonary artery 10 to the vena cava 24 may be undesirable because introducing high pressure into the vena cava 24 could induce or exacerbate heart failure symptoms due to the immediate return of blood to the right side of the heart. Therefore, it is preferable to divert blood from the right pulmonary artery 10 into the azygos vein 14 at a location upstream of where the blood joins the vena cava 24. In particular, it is preferable to direct blood into the azygos vein 14 in a direction opposite its antegrade flow. This allows high-pressure flow diverted from the pulmonary artery 10 to dissipate within the much lower-pressure azygos vein 14, including through access to the network of intercostal veins 20 that communicate with the azygos vein 14, all of which encompass a large-volume, low-pressure vasculature that can absorb and dissipate the relatively low-flow rate of high-pressure blood diverted from the pulmonary artery 10 before the diverted blood is directed downstream into the vena cava 24.

[0009] 2 and 3, an exemplary shunt device 40 that can be used to shunt blood from one location in the body of an animal (e.g., human) subject will be described. Figure 2 shows a perspective view of the shunt device 40 itself, and Figure 3 shows a cross-sectional view of the shunt device 40 applied to the azygos vein 14 and right pulmonary artery 10 of a human subject. In particular, openings 42, 44 (see Figure 3) can be formed in a wall 46 of the azygos vein 14 and a wall 48 of the right pulmonary artery 10, respectively, and the shunt device 40 can be secured to the walls 46, 48 so as to extend through the openings 42, 44 and provide fluid communication between the lumens 50, 52 of the azygos vein 14 and the right pulmonary artery 10, respectively.

[0010] The shunt device 40 includes a shunt frame assembly 54 having a first anchor 60 and a second anchor 62 extending annularly about a common central axis X. The shunt frame assembly 54 further includes an intermediate portion 64 extending between and connected to the first anchor 60 and the second anchor 62. The intermediate portion 64 defines a window 66 through the shunt frame assembly 54 that is coaxial with the central axis X. Additionally, the shunt device 40 further includes a flow director 68 extending distally from the shunt frame assembly 54 and defining a fluid pathway 74 and a distal opening 76 at the end of the pathway 74. (For purposes of this disclosure, the terms "distal" and "proximal," when describing features of the shunt device 40, are relative to the passageway through which fluid flows or can flow through the shunt device 40, with distal features being closer to the end of the flow path than proximal features.)

[0011] As described later herein, the shunt device 40 is a flexible structure that is manipulable from the configuration shown in Figures 2 and 3 to a collapsed configuration (see Figure 5) that allows the shunt device 40 to be loaded into an associated delivery system 120 (see Figures 6-9) for implantation. During the implantation process, the delivery system 120 is operable to manipulate the shunt device 40 from its collapsed configuration back to the configuration shown in Figures 2 and 3, which may be referred to as the "shunt configuration" of the device 40. Features of the shunt device 40 will now be described with respect to their shape and arrangement in the shunt configuration.

[0012] In the shunt configuration, each of the anchors 60, 62 is a ring-like body that radially expands such that its outer diameter is larger in the shunt configuration compared to the collapsed configuration (it should be understood that the central axis X of the shunt frame assembly 54 defines the axial and radial directions of the shunt device 40). The outer diameters of the first anchor 60 and the second anchor 62 are preferably larger than the diameters of the opening 42 of the azygos vein 14 and the opening 44 of the right pulmonary artery 10, respectively. Furthermore, the intermediate portion 64 of the shunt frame assembly 54 is an annular body that connects the anchors 60, 62 and includes a flexible material membrane (e.g., urethane foam, woven or braided fabric, expanded polytetrafluoroethylene, electrospun polyurethane, thermoplastic polyurethane, polyethylene terephthalate, polyurethane, silicone, gelatin-blended nanofiber membrane, etc.) that can conform to (e.g., fit) the opening 42 of the azygos vein 14 and the opening 44 of the right pulmonary artery 10. At least a portion of the intermediate section 64 can be treated with at least one therapeutic agent that is eluted into the blood vessels (PA-AV), ventricles, and / or cardiac tissue. The therapeutic agent may be capable of preventing various pathological conditions, including, but not limited to, arrhythmias, thrombosis, systemic hypertension, pulmonary hypertension, stenosis, apoptosis, and inflammation. Accordingly, the therapeutic agent may include at least one of an antiarrhythmic agent, an anticoagulant, an antioxidant, a fibrinolytic agent, a steroid, an antiapoptotic agent, an anti-overgrowth agent (i.e., capable of preventing overgrowth of epithelial cells), and / or an anti-inflammatory agent. Optionally or additionally, the therapeutic agent may be capable of treating or preventing other diseases or disease processes, such as microbial infections and heart failure. In these cases, the therapeutic agent may include a cardiac agent, a chronotropic agent, an antimicrobial agent, and / or a biological agent, such as a cell or protein. Examples of acceptable therapeutic agents include heparin, synthetic heparin analogs (e.g., fondaparinux), G(Gp)II, and the like. b / III ainhibitors, vitronectin receptor antagonists, hirudin, antithrombin III, drotrecogin alpha; fibrinolytic agents such as alteplase, plasmin, lysokinase, factor XIIa, factor VIIa, prourokinase, urokinase, streptokinase; platelet aggregation inhibitors such as ticlopidine, clopidogrel, abciximab, dextran; corticosteroids such as alclometasone, estradiols such as 17β-estradiol, amcinonide, potentiated betamethasone, beclomethasone, betamethasone, budesonide; fibrinolytic agents such as tissue plasminogen activator, Examples of such anti-inflammatory drugs include streptokinase, dipyridamole, ticlopidine, clopidine, and abciximab; non-steroidal anti-inflammatory drugs, such as salicylic acid and salicylic acid derivatives, para-aminophenol derivatives, indole and indene acetic acids (e.g., etodolac, indomethacin, and sulindac), heteroaryl acetic acids (e.g., ketorolac, diclofenac, and tolmetin); pulmonary artery dilating drugs, prostacyclin, soluble guanylate cyclase (sGC) stimulators, epoprostenol, treprostinil sodium, selexipag, sildenafil, and tadalafil.

[0013] The shunt device 40 can be implanted such that the first anchor 60 is positioned inside the venous wall 46, the second anchor 62 is positioned inside the arterial wall 48, and the intermediate portion 64 extends through the openings 42, 44 in the walls 46, 48. The intermediate portion 64 preferably applies a slight axial tension to the anchors 60, 62, thereby pressing the anchors 60, 62 (directly or indirectly) against their respective walls 46, 48. This allows a seal to be formed between each wall 46, 48 and its associated anchor 60, 62, thereby preventing fluid within the azygos vein 14 and right pulmonary artery 10 from leaking between the walls 46, 48 and the shunt frame assembly 54.

[0014] As such, the shunt frame assembly 54 in the shunt configuration can anchor the shunt device 40 to the wall 46 of the azygos vein 14 and the wall 48 of the right pulmonary artery 10, establishing a sealing window 66 through the walls 46, 48. Furthermore, when deployed, the central axis X of the shunt frame assembly 54 is substantially perpendicular to the longitudinal axes of the azygos vein 14 and the right pulmonary artery 10 at the location of the shunt device 40.

[0015] In the shunt configuration, the second anchor 62 defines a proximal opening 78 of the shunt device 40. Additionally, the flow director 68 extends distally from the second anchor 62 through a fenestration 66 in the shunt frame assembly 54, such that the flow director 68 extends distally beyond the first anchor 60 (e.g., into the lumen 50 of the azygos vein 14). Thus, fluid from the right pulmonary artery 10 can enter the shunt device 40 through the proximal opening 78, flow through the passageway 74 of the flow director 68, and then exit into the azygos vein 14 via the distal opening 76.

[0016] Notably, fluid from the right pulmonary artery 10 may enter the fluid path 74 of the flow director 68 in a first direction D1 that is substantially parallel to the central axis X of the frame assembly (and substantially perpendicular to the longitudinal axes of the azygos vein 14 and right pulmonary artery 10 at the location of the shunt device 40). However, as the fluid travels toward the distal opening 76, the inner surface 84 of the flow director 68 may redirect at least a portion of the fluid to exit the distal opening 76 in a second direction D2 that is transverse (e.g., substantially perpendicular) to the first direction D1 and the central axis X. More specifically, the inner surface 84 is gradually curved such that fluid in the first direction D1 may impinge upon the inner surface 84 and be redirected toward and through the distal opening 76 in the second direction D2.

[0017] The second direction D2 is preferably substantially parallel to but opposite the antegrade flow of blood in the azygos vein 14, although a non-parallel direction opposite the antegrade flow is also possible. For example, the angle between the second direction D2 and the direction of antegrade flow in the azygos vein 14 can be 45 degrees or less, preferably 15 degrees or less. In other words, the angle between the second direction D2 and the central axis X (or the first direction D1) can be about 45 degrees to about 135 degrees, preferably about 75 degrees to about 105 degrees. Furthermore, the distal opening 76 is preferably located a certain distance (e.g., at least 1 cm, preferably at least 2 cm, and most preferably at least 3 cm) from the point where the azygos vein 14 joins the vena cava 24.

[0018] In the shunt configuration, the flow director 68 of this embodiment has a unique geometry that enables the flow redirection described above. More specifically, as shown in FIG. 3 , the lower end of the flow director 68 is generally tubular, and the upper end has a rounded hood that defines a curved inner surface 84. However, it should be understood that the flow director 68 may have a variety of other geometries and configurations without departing from the scope of the present disclosure. For example, the upper portion of the flow director 68 may comprise an elongated tube (e.g., a stent or collapsible tube) that is curved and extends upstream into the lumen 50 of the azygos vein 14, with a distal outlet of the tube discharging fluid in a direction transverse to the central axis X. Generally speaking, the flow director 68 may have any configuration that defines a fluid pathway and discharges fluid in a direction transverse to the central axis X.

[0019] As mentioned above, the shunt device 40 is a flexible structure that can be manipulated into the collapsed configuration of Figure 5, which allows the shunt device 40 to be loaded into a delivery system (see Figures 6-9) for implantation. Additionally, one or more features of the shunt device 40 can be resiliently biased toward the shunt configuration to facilitate manipulation of the shunt device 40 from the collapsed configuration back to the shunt configuration.

[0020] For example, as best shown in FIG. 2 , the first anchor 60 comprises an annular wire body 90 having a plurality of triangular cusps 92 circumferentially aligned about a central axis X. In the shunt configuration, each triangular cusp 92 faces radially relative to the central axis X. Furthermore, the wire body 90 comprises a shape-memory material (e.g., nitinol) that is flexible but resiliently biased toward the configuration of FIG. 2 . As a result of this design, the angle of each cusp 92 can be decreased to reduce the inner and outer diameters of the first anchor 60. Conversely, the angle of each cusp 92 can also be increased to increase the inner and outer diameters of the first anchor 60. Furthermore, the first anchor 60 can be manipulated to flip each cusp 92 so that the cusp 92 faces in a direction substantially parallel to the central axis (e.g., downward in FIG. 2 ). With the apexes axially oriented and the angle of each apex reduced, first anchor 60 can have a generally tubular shape with a relatively small diameter compared to its shape in the shunt configuration, and first anchor 60 is resiliently biased to return from its tubular shape to the shunt configuration.

[0021] As another example, the shunt device 40 can include an elastic body 100 that forms the second anchor 62 and flow director 68 of the shunt device 40 and is elastically biased toward the shunt configuration of these features. FIG. 4 shows the body 100 as it appears after being slit open longitudinally (e.g., axially) and flattened. As shown in FIG. 4, the body 100 includes a flexible, laser-cut frame 102 having a plurality of bands 104a-104e, each of which includes a plurality of loops 106 that are aligned and joined to one another. The body 100 further includes a flexible membrane 108 affixed to the frame 102, allowing the membrane 108 to conform and follow the shape of the frame 102. In this example, the membrane 108 includes an impermeable elastic layer of material (e.g., expanded polytetrafluoroethylene, urethane derivatives, polyethylene terephthalate, etc.) that encases the frame 102, with the frame 102 embedded within the membrane 108. However, membrane 108 may comprise other permeable or impermeable materials (eg, fabrics) and may be affixed to frame 102 in alternative ways (eg, adhesive bonding, stitching, etc.).

[0022] The left and right ends of the bands 104c-104e and the membrane 108 in Figure 4 can be joined together such that the body 100 forms a tubular structure about the central axis X. Furthermore, the frame 102 and the membrane 108 can be elastically deformed to assume the shunt configuration of the body 100 in Figure 2. In particular, the spacing between the loops 106 in each band 104a-104e can be enlarged in areas of larger diameter, and the loops 106 can bend to form a curvature of the body 100 along the central axis X. Furthermore, the membrane 108 is affixed to the frame 102 so that it elastically deforms with the frame 102.

[0023] The frame 102 of the body 100 preferably comprises a shape-memory material (e.g., nitinol) that is resiliently biased toward the shunt configuration of Figure 2. Thus, the body 100 can be manipulated from the shunt configuration to the collapsed configuration of Figure 5, but is resiliently biased to facilitate manipulation back to the shunt configuration. Furthermore, the resilient bias of the body 100 (which forms the second anchor 62 and the flow director 68) can ensure that the body 100 retains its shape in the shunt configuration and maintains patency through the passageway 74.

[0024] As discussed above, the elastic body 100 forms the second anchor 62 and the flow director 68 of the shunt device 40. However, it should be understood that the elastic body 100 may form additional or fewer elements of the shunt device 40. For example, in some embodiments, the elastic body 100 may form the entire shunt device 40. In such instances, the wire frame 102 is configured such that each respective element of the shunt device 40 is elastically biased toward its shunt configuration.

[0025] Furthermore, it should be understood that the features of the shunt device 40 described above may have other shapes and configurations (e.g., materials, components, etc.) without departing from the scope of the present disclosure. For example, the first anchor 60 and the second anchor 62 may have other shapes and configurations that allow them to radially expand to have respective dimensions (e.g., widths or diameters) that are greater than the respective diameters of the opening 42 of the azygos vein 14 and the opening 44 of the right pulmonary artery 10.

[0026] The manner in which the shunt device 40 is manipulated to assume the collapsed configuration will now be described in more detail. Specifically, from the shunt configuration of Figures 2 and 3, the shunt device 40 can be adapted to the collapsed configuration of Figure 5 by pulling the first anchor 60 in direction D3 away from the distal opening 76. As the first anchor 60 approaches the second anchor 62, the first anchor 60 can radially expand (e.g., by decreasing the angle between its cusps 92) and / or the second anchor 62 can radially contract (e.g., by decreasing the spacing between its loops 106) to cause the first anchor 60 to slide over and past the second anchor 62. The first anchor 60 can then be further pulled in direction D3 away from the second anchor 62 and the distal opening 76 until tension is generated in the shunt device 40. As the first anchor 60 is further pulled in tension, the shunt device 40 contracts radially and expands axially, particularly at the first anchor 60 and the second anchor 62. Eventually, the shunt device 40 assumes the collapsed configuration of Figure 5, resulting in a generally tubular structure having the first anchor 60 at one end and the distal opening 76 at the other end. Notably, the pointed end 92 of the first anchor 60 is axially oriented in the collapsed configuration.

[0027] The shunt device 40 can be returned to its shunt configuration by moving the first anchor 60 back in direction D1 toward the distal opening 76. Once the first anchor 60 approaches the second anchor 62, the first anchor 60 can radially expand (e.g., by increasing the angle between its apices 92) and / or the second anchor 62 can radially contract (e.g., by increasing the spacing between its loops 106) to slide the first anchor 60 over the second anchor 62. The first anchor 60 can then be further moved in direction D1 toward the distal opening 76, and the resilient bias of the body 100 and first anchor 60 can facilitate returning the shunt device 40 to its shunt configuration.

[0028] 6-9, an exemplary method of implanting the shunt device 40 will now be described. FIG. 6 illustrates a first step in delivering the shunt device 40 to the lumen 50 of the azygos vein 14. More specifically, the shunt device 40 can be loaded into a delivery system 120 that includes a guidewire lumen 126, a dilator 128, and a sheath system 130 having an inner sheath 132 and an outer sheath 134. The inner sheath 132 extends at least partially within the outer sheath 134, the dilator 128 extends at least partially within the inner sheath 132, and the guidewire lumen 126 extends at least partially within the dilator 128 (as well as the inner sheath 132 and outer sheath 134). The guidewire lumen 126, the dilator 128, the inner sheath 132, and the outer sheath 134 are translatable relative to one another such that the dilator 128 can translate along the guidewire lumen 126, the inner sheath 132 can translate along the dilator 128, and the outer sheath 134 can translate along the inner sheath 132.

[0029] The shunt device 40 can be loaded into the delivery system 120 in its collapsed configuration, with the guidewire lumen 126 and dilator 128 extending through the shunt device 40. In particular, the shunt device 40 can be oriented over the guidewire lumen 126 and dilator 128 such that its first anchor 60 is positioned closer to the distal end of the guidewire lumen 126 and dilator 128 than its flow director 68. Additionally, the sheath system 130 can radially restrain the shunt device 40, thus preventing it from radially expanding toward its shunt configuration.

[0030] The delivery system 120 can be used to deliver the shunt device 40 in its collapsed configuration into the lumen 50 of the azygos vein 14. Preferably, this is a percutaneous intervention rather than open-heart surgery, offering the advantage of being less invasive. To accomplish this, the delivery system 120 can be inserted through the jugular, radial, or femoral vein via a modified Seldinger technique to reach the lumen 50 of the azygos vein 14 (via the vena cava 24). However, alternative routes to the lumen 50 may be utilized in other embodiments.

[0031] Once the delivery system 120 reaches the lumen 50, the needle at the distal end of the guidewire lumen 126 can penetrate the wall 46 of the azygos vein 14 and the wall 48 of the right pulmonary artery 10, and the nosecone 136 at the distal end of the dilator 128 can then be advanced to form the openings 42, 44 for the shunt device 40. The openings 42, 44 are preferably located some distance (e.g., at least 1 cm, preferably at least 2 cm, and most preferably at least 3 cm) from where the azygos vein 14 joins the vena cava 24.

[0032] 7 and 8 illustrate a first anchoring step in which the first anchor 60 of the shunt device 40 is deployed and secured to the wall 46 of the azygos vein 14. More specifically, as shown in FIG. 7, the outer sheath 134 can be actuated to retract relative to the guidewire lumen 126, the inner sheath 132, and the shunt device 40, thereby releasing the first anchor 60 from its constraint. As a result, the first anchor 60 radially expands from its collapsed configuration (due to its resilient bias) to its shunt configuration. Thereafter, as shown in FIG. 8, the inner sheath 132 can be actuated to advance relative to the guidewire lumen 126 and the outer sheath 134. During this advancement, the inner sheath 132 engages and presses against the intermediate portion 64 of the shunt device 40, thereby translating the shunt device 40 along the guidewire lumen 126 with the inner sheath 132 until the first anchor 60 is pressed (directly or indirectly) against the wall 46 of the azygos vein 14, thereby securing the first anchor 60 to the wall 46.

[0033] As the inner sheath 132 is further advanced into the openings 42, 44 in the lumen walls 46, 48, the first anchor 60 remains stationary against the wall 46 of the azygos vein 14, while the inner sheath 132 retracts other portions of the shunt device 40 through the openings 42, 44. For example, as seen in Figures 8 and 9, the inner sheath 132 retracts the intermediate portion 64 through the openings 42, 44, thereby everting the intermediate portion 64 so that it surrounds the inner sheath 132 and extends from the first anchor 60 into the openings 42, 44.

[0034] Finally, a second anchoring step is performed by further advancing the inner sheath 132 relative to the guidewire lumen 126 and the outer sheath 134. More specifically, as shown in FIG. 9 , the inner sheath 132 can be advanced until the second anchor elements 62 of the shunt device 40 are withdrawn through the openings 42, 44 in the lumen walls 46, 48 and released from their restraints. As a result, the second anchors 62 radially expand (due to their resilient bias) from their collapsed configuration to their shunt configuration. Furthermore, the intermediate portions 64 apply a slight tension to the anchors 60, 62 in the axial direction, thereby pressing the anchors 60, 62 (directly or indirectly) against their respective walls 46, 48. In other words, the anchors 60, 62 apply a compressive force to the composite wall structure of the lumen walls 46, 48, thereby anchoring the shunt device 40 to the lumen walls 46, 48.

[0035] Finally, the implantation process can be completed by retracting the inner sheath 132 and guidewire lumen 126 relative to the shunt device 40. That is, the inner sheath 132 is retracted, releasing the flow director 68 from its restraint and allowing the inner sheath 132 (and its inner diameter) to radially expand. The flow director 68 then radially expands from its collapsed configuration (due to its resilient bias) to its shunt configuration. Furthermore, the guidewire lumen 126 can be retracted through the flow director 68 until it completely exits the shunt device 40. This results in the shunt device 40 assuming its final configuration as described above with respect to FIG. 3.

[0036] The above-described shunt device 40 and its implantation method can be used to treat PH because the implanted shunt device 40 can divert blood from the right pulmonary artery 10 into the azygos vein 14. Specifically, pressure within the right pulmonary artery 10 is relieved by diverting blood into the azygos vein 14 upstream of where the blood intersects with (and terminates at) the superior vena cava 24. In this manner, the shunt device 40 can receive blood flow from the right pulmonary artery 10 and redirect it along a retrograde, substantially coaxial path into the azygos vein 14, where pressure is lower (thereby relieving pressure within the right pulmonary artery 10). The azygos vein 14 and its upstream vascular network can therefore absorb and dissipate excess pressure from the pulmonary artery 10 with minimal adverse effects. As a result, the relief of pulmonary artery pressure by the shunt device 40 reduces clinical symptoms in patients with pulmonary hypertension and heart failure.

[0037] However, it should be understood that the shunt device 40 and its implantation method may be used to treat conditions other than PH. Indeed, the shunt device 40 may similarly be implanted to divert blood to and / or from different regions of the body. In some instances, the shunt device 40 may be used to divert blood between two body lumens separated by a common wall. In other instances, the shunt device 40 may be used to divert blood between two blood vessels having separate, spaced-apart walls. In such instances, the intermediate portion 64 may be configured to radially expand in the shunt configuration to act as a spacer between the walls.

[0038] Additionally, the shunt device 40 can incorporate features such as radiopaque markers or intelligent sensors that can monitor key metrics, such as pressure and flow, in real time during operation and enable optimization of such metrics. For example, as shown schematically in FIG. 2 , the shunt device 40 can include multiple radiopaque markers 150 disposed on (e.g., formed with or attached to) the flow director 68. One or more markers 150 can be disposed at the distal end of the flow director 68 or at a location between its proximal and distal ends. In some instances, a set of markers 150 can be circumferentially aligned around the flow director 68, with the angular distance (relative to the central axis X) between adjacent markers 150 of the set being approximately 50 to 70 degrees (preferably approximately 60 degrees) or approximately 80 to 100 degrees (preferably approximately 90 degrees). Furthermore, in some instances, one or more markers 150 can be disposed at a location inward of the first anchor 60 between adjacent cusps 92. Such a location of the marker 150 can be useful in determining whether the shunt device 40 is properly expanded to its shunt configuration.

[0039] As another example, a pressure sensor may be affixed to the proximal end of the shunt device 40 and delivered toward the patient's heart. Furthermore, the sensor may be foldable so that it folds along with the shunt device 40. The pressure sensor may provide pressure-related data using an external measurement device. Various excitation systems, such as a transmitting antenna, may be electromagnetically coupled to the sensor to communicate pressure data from the sensor to an analyzer, which may be used in conjunction with an interface module for real-time use by a physician. A current may be induced in the sensor, causing it to oscillate at the sensor's resonant frequency. This oscillation changes the frequency spectrum of the transmitted signal. From this change, the bandwidth and resonant frequency of a particular sensor may be determined using an impedance system, and from these bandwidths and resonant frequencies, the corresponding pressure change may be calculated.

[0040] Additionally or alternatively, a flow sensor can be incorporated into the distal end of the flow director 68. A flow sensor can similarly provide information about blood flow within the patient that can optimize the use of the shunt device 40. Knowing the fluid flow within the shunt device 40 allows its behavior to be predicted mathematically.

[0041] FIG. 10 shows another embodiment of a shunt device 40a connecting the pulmonary artery to the superior vena cava. In this embodiment, the shunt device 40a is anchored to the walls of the right pulmonary artery 10 and the vena cava 24, providing a window therethrough. Additionally, the flow director 68 is a stent (e.g., a covered stent) that advances from the shunt frame assembly 54 into the superior vena cava 24 and then into the azygos vein 14. At the distal end of the flow director 68, a cone 150 is coaxially positioned around the flow director 68. The wider end of the cone 150 is positioned toward the distal end of the flow director 68, and the opposite end of the cone 150 is fitted to the flow director 68. The cone 150 serves as an anchor to secure the distal opening 76 of the flow director 68 within the azygos vein 14 and also serves to fix the longitudinal position of the cone 150 within the azygos vein 14 upstream of where the azygos vein 14 joins the vena cava 24. The cone 150 can act as a means for substantially centering the distal opening 76 of the flow director 68 within the azygos vein 14. Additionally, the cone 150 can fit over the distal-most end of the flow director 68. The cone 150 can be made from a porous mesh material that allows blood to pass through, such as a bare metal frame. Other porous materials that allow blood to pass through may be suitable alternatives. Alternatively, the cone 150 elements may be provided as simple wire-based structures (e.g., nitinol wires), with opposing wire segments that hold the cone 150 in place relative to the flow director 68 and, together with the flow director 68, present a substantially trapezoidal shape when viewed from the side.

[0042] 10 has a Venturi configuration, with the distal opening 76 having a smaller diameter than the passageway at the proximal end of the flow director 68. This allows the device to utilize Bernoulli's principle of energy conservation to reduce the pressure (and increase the flow rate) of blood diverted from the pulmonary artery 10 and delivered to the azygos vein 14. These effects serve two purposes: a) to reduce the pressure of the diverted blood before it is delivered to the azygos vein 14, thereby reducing the amount of dissipation / absorption required within the azygos / intercostal venous network to accommodate the diverted blood; and b) to increase the flow rate of the diverted blood as it enters the azygos vein 14 in the retrograde direction through the distal opening 76 of the flow director 68, thereby allowing the diverted blood to reach and access deeper portions of the azygos / intercostal venous system and dissipate its pressure before being redirected back to the vena cava 24.

[0043] Furthermore, it should be understood that other types of delivery systems and methodologies may be used to implant the shunt device 40 without departing from the scope of the present disclosure. For example, the sheath system 130 of the delivery system 120 described above includes an inner sheath 132 and an outer sheath 134 that are translatable relative to one another. In other examples, the sheath system 130 may include a single sheath that constrains the shunt device 40 and translates relative to the guidewire lumen 126 to sequentially release portions of the shunt device 40 in the manner described above. Other exemplary methods of implanting the shunt device 40 or other shunts are briefly described below.

[0044] One exemplary retrograde implantation method includes: 1) obtaining wire access via a modified Seldinger technique through the internal jugular, radial, or femoral vein to the right atrium (RA) and advancing the wire across the tricuspid and pulmonary valves to the right pulmonary artery (RPA); 2) advancing a second wire via a modified Seldinger technique through the femoral vein and advancing the wire toward the azygos vein (AZV) and into the superior vena cava (SVC); 3) advancing a catheter and needle or wire through the inferior wall of the AZV to the anterior wall of the RPA under fluoroscopic and echocardiographic guidance; 4) advancing the wire toward the left PA and into the main PA and advancing a dilatation catheter over the wire; and 5) exchanging the second wire for a snare wire within the PA and advancing the first RPA wire. 5) grasping the RPA / AZV shunt and pulling it across the RPA-AZV wall, then advancing a dilation catheter over the wire into the AZV; 6) advancing the RPA / AZV shunt over the wire until it reaches the AZV; 7) retracting the delivery sheath until the distal portion of the RPA / AZV shunt is released within the AZV; 8) pulling back the RPA / AZV stent-shunt until the AZV side of the shunt is anchored or attached to the inferior AZV wall; and 9) deploying the RPA side of the stent-shunt and securing it in place by retracting the delivery sheath, thereby removing the delivery system; and blood flow through the RPA / AZV shunt can be assessed and quantified by echocardiography, and changes in PA pressure can be measured with a Swan-Ganz catheter.

[0045] Another exemplary antegrade implantation method involves: 1) obtaining wire access to the RA via a modified Seldinger technique through the internal jugular, radial, or femoral vein; 2) advancing the wire across the tricuspid and pulmonary valves to reach the RPA; 3) advancing a needle or wire across the anterior wall of the RPA to reach the inferior wall of the AZV and passing the needle or wire under fluoroscopic and echocardiographic guidance; and 4) advancing a wire into the AZV and advancing a dilatation catheter over the wire to deliver a collapsible RPA / AZV stent-shunt. 4) continuing to advance the delivery sheath into the AZV; 5) retracting the delivery sheath until the RPA / AZV stent-shunt is released within the AZV and pulling it back to anchor the stent-shunt to the AZV wall; and 6) pulling back the delivery sheath to release and secure the RPA side of the RPA / AZV stent-shunt in place, thereby removing the delivery system; blood flow through the RPA / AZV stent-shunt can be assessed and quantified by echocardiography, and changes in PA pressure can be measured with a Swan-Ganz catheter.

[0046] Another exemplary retrograde implantation method includes: 1) obtaining wire access to the RA via a modified Seldinger technique through the internal jugular, radial, or femoral vein; 2) advancing the wire across the tricuspid and pulmonary valves to the RPA; 3) advancing a second wire via a modified Seldinger technique through the femoral vein and into the SVC; 4) advancing a catheter and needle or wire through the posterior SVC wall to the anterior RPA wall under fluoroscopic and echocardiographic guidance; 5) advancing the wire into the main PA toward the left PA and advancing a dilation catheter over the wire; 6) exchanging the second wire for a snare wire within the PA and grasping and withdrawing the first RPA wire across the RPA-SVC wall; and 7) advancing the second wire through the SVC and into the RPA-SVC wall under fluoroscopic and echocardiographic guidance. 8) advancing the RPA / AZV shunt over the wire until it reaches the AZV; 9) retracting the delivery sheath until a distal portion of the RPA / AZV shunt is released within the AZV; 10) withdrawing the RPA / AZV shunt until the SVC side of the shunt is anchored or attached to the posterior SVC wall; and 11) deploying the RPA side of the shunt and securing it in place by retracting the delivery sheath, thereby removing the delivery system; and blood flow through the RPA / AZV stent-shunt can be assessed and quantified by echocardiography, and changes in PA pressure can be measured with a Swan-Ganz catheter.

[0047] Another exemplary antegrade implantation method involves: 1) obtaining wire access to the RA via a modified Seldinger technique from the internal jugular, radial, or femoral vein; 2) advancing the wire across the tricuspid and pulmonary valves to reach the RPA; 3) advancing a needle or wire across the anterior wall of the right pulmonary artery (RPA) to reach the posterior wall of the SVC and passing the needle under fluoroscopic and echocardiographic guidance; and 4) advancing a wire into the SVC towards the azygos vein (AZV) and advancing a dilatation catheter over the wire to implant a collapsible RPA / SVC catheter. 4) advancing the delivery sheath with the AZV shunt further into the AZV; 5) retracting the delivery sheath until the RPA / AZV shunt is released within the AZV and pulling it back to anchor the shunt to the SVC wall; and 6) pulling back the delivery sheath to release and secure the RPA side of the RPA / AZV shunt in place, thereby removing the delivery system; and blood flow through the RPA / AZV stent-shunt can be assessed and quantified by echocardiography, and changes in PA pressure can be measured by a Swan-Ganz catheter.

[0048] The present invention has been described with reference to the exemplary embodiments set forth above. Modifications and variations will occur to others upon reading and understanding this specification. The exemplary embodiments incorporating one or more aspects of the present invention are intended to include all such modifications and variations insofar as they come within the scope of the appended claims.

Claims

1. 1. A shunt device operable between a collapsed configuration and a shunt configuration, comprising:

1. A shunt frame assembly comprising: a first anchor at a first end of the shunt frame assembly configured to radially expand from the collapsed configuration toward the shunt configuration; a second anchor at a second end of the shunt frame assembly configured to radially expand from the collapsed configuration toward the shunt configuration, the second anchor defining a proximal opening of the shunt device in the shunt configuration; Equipped with the first anchor and the second anchor define a common central axis; a shunt frame assembly; a flow director extending distally from the shunt frame assembly and defining a fluid pathway and a distal opening at one end of the fluid pathway; Equipped with In the shunt configuration, the shunt device is configured to receive fluid through the proximal opening, transport the fluid through the fluid pathway, and discharge the fluid through the distal opening; The flow director is configured to redirect at least a portion of the fluid flowing through the fluid pathway so that the at least a portion of the fluid is discharged through the distal opening in a fluid direction transverse to the central axis.

2. The shunt device of claim 1 , wherein the first anchor and the second anchor are resiliently biased to radially expand from the collapsed configuration.

3. The shunt device of claim 1 , wherein the first anchor comprises an annular body having a plurality of anchor elements circumferentially aligned about the central axis.

4. The shunt device of claim 3 , wherein the anchor elements are oriented radially in the shunt configuration and axially in the collapsed configuration.

5. The shunt device of claim 1, wherein the shunt device comprises an elastic body forming the second anchor portion and the flow director, the elastic body comprising a wire frame and a membrane affixed to the wire frame.

6. The shunt device of claim 5 , wherein the wire frame is embedded in the membrane.

7. 2. The shunt device of claim 1, wherein the shunt frame assembly comprises an intermediate portion extending between and connected to the first anchor and the second anchor, the intermediate portion defining a window coaxial with the central axis.

8. The shunt device of claim 7, wherein in the shunt configuration, the flow director extends distally from the second anchor through the window in the intermediate portion, thereby extending distally beyond the first anchor.

9. The shunt device of claim 1, wherein the angle between the fluid direction and the central axis is between about 45 degrees and about 135 degrees.

10. 10. A method of implanting a shunt device according to claim 1 to provide fluid communication between a first body lumen and a second body lumen separated by a wall structure, comprising: a delivering step including delivering the shunt device to the first body lumen in the collapsed configuration; a first anchoring step including radially expanding the first anchor within the first body lumen; a second anchoring step including radially expanding the second anchor within the second body lumen such that the first anchor and the second anchor secure the shunt device to the wall structure; Including, The shunt device is in the shunt configuration providing fluid communication between the first body lumen and the second body lumen.

11. The method of claim 10, wherein the delivering step includes delivering the shunt device using a delivery system comprising a guidewire lumen and a sheath system, the guidewire lumen extending through the shunt device, and the sheath system radially restraining the shunt device in the collapsed configuration.

12. The method of claim 10 , wherein the first anchoring step includes operating a sheath system to release the first anchor.

13. The method of claim 12 , wherein the second anchoring step includes operating the sheath system to release the second anchor.

14. The method of claim 10 , wherein the method includes forming an opening in the wall structure prior to the first anchoring step.

15. The method of claim 10 , wherein the wall structure comprises a first wall defining the first body lumen and a second wall defining the second body lumen.

16. The method of claim 10 , wherein after the second anchoring step, the first anchor and the second anchor apply a compressive force to the wall structure.

17. 11. The method of claim 10, wherein the shunt frame assembly comprises an intermediate portion extending between and connected to the first anchor and the second anchor, the intermediate portion applying tension to the first anchor and the second anchor.

18. In the shunt configuration, the shunt device receives fluid through the proximal opening, conveys the fluid through the fluid pathway, and discharges the fluid through the distal opening; 11. The method of claim 10, wherein the flow director redirects at least a portion of the fluid flowing through the fluid pathway such that the at least a portion of the fluid is discharged through the distal opening in the fluid direction transverse to the central axis.

19. the first body lumen is the lumen of an azygos vein of a subject; The method of claim 10 , wherein the second body lumen is the lumen of the subject's right pulmonary artery.

20. 20. The method of claim 19, wherein in the shunt configuration, the distal opening of the shunt device is located at least 1 cm from where the azygos vein intersects with the subject's superior vena cava.

Images