The present disclosure relates to vascular and tissue closure devices, and, more specifically, to occlusion devices and methods for the closure of multi-vessel apertures, caused by venous-arterial access.
Complete percutaneous access into the arterial system up to the heart is desired. Limiting factors to this are arteries that do not facilitate current devices because of vessels that are atherosclerotic, tortuous, have a small diameter, are calcified, or have porcelain internal vascular walls. Anatomically parallel to the arterial system is the venous system, which does not typically have the same limiting properties. Percutaneous access into the venous system into the arterial system is advantageous and has been demonstrated and most impactful in caval-aortic procedures.
Transcaval access (TCA) is a new catheter technique that enables non-surgical introduction of large devices, such as transcatheter heart valves, into the abdominal aorta. TCA involves the creation of a conduit from the inferior vena cava (IVC) to the abdominal aorta (AA) by way of intravascular puncture and obturation of the resulting fistula. This fistula enables the introduction of large bore systems in a manner that bypasses existing arterial limitation. Upon completion of the TCA the caval-aortic fistula is closed with a commercial nitinol occluder device that is an off-label use. Such occluders have important limitations, such as residual bleeding and theorized potential complications. TCA has been performed successfully in dozens of patients to date.
However, in addition to closure limitations, the current method of caval-aortic crossing is limited in accuracy. Initially all patients undergoing TCA are assessed via computed tomography (CT) for anatomical features, as well as the identification of an ideal crossing zone and angle. This ideal crossing point is only assessed from within the AA, and it is defined as the least diseased, calcific, and obstructed portion of the AA. This ideal crossing point is also associated with a radiological angle, which is currently the sole means of synchrony between the CT and the fluoroscopic imaging during the procedure. The typical current method of crossing is as follows: Vascular access is gained in both the right femoral artery and right femoral vein. From within the artery an Amplatz GooseNeck® Snare (Covidien, Dublin, Ireland) is advanced into the arterial side, up until the snare is locate approximately at the site of ideal crossing. Through the venous side a 5 French Soft-Vu® Cobra Catheter (Angiodynamics, Inc., Latham, N.Y.) is advanced until parallel to the snare, it is then articulated so the distal end of the catheter is directed toward the snare. An ASAHI Confianza® 0.014″ Wire (Abbott Vascular, Santa Clara, Calif.) is blunted at the distal end, and an electrosurgery pencil is attached to the tip of the wire. This wire is then inserted into a 0.035″ PiggyBack° Wire Converter (Vascular Solutions, Inc. Minneapolis, Minn.) and this entire system is advanced within the Cobra Catheter. This system is then advanced out of the cobra catheter and the CT defined radiological angle is found. The system is rotated until facing the center of the parallel snare. This portion of the method is inaccurate, using an approximation for puncture based on a snare with a substantially larger diameter than the site of crossing. In addition, the IVC is a relatively dynamic vessel, directly influenced by the patient's respiration and fluid levels. This causes constant motion of the catheter system, and further decreases crossing accuracy. Once the system is placed in an approximated target zone, the wire system is engaged and the wire is rapidly punctured through the IVC wall into the interstitial space, and then through the AA wall. Common difficulties during this crossing are collision with calcific nodes within the AA, improper positioning, and puncture of additional structures. Upon puncture in the AA, the wire system is snared and exchanged for a stiff 0.035″ wire (of any configuration). The snared wire is then advanced upwards into the descending aorta, where it becomes an “S-like” guiderail for the large bore devices. Currently this method utilizes existing devices that are not purpose built for this type of procedure, which coupled with the lack of accuracy creates increased risk for an otherwise beneficial procedure.
According to one aspect, further details of which are described herein, a tubular implant, preferably embodied as an occulder, includes a tubular body covered partially by a hemostatic material and a hub extending at an angle from the tubular body. The implant is configured for deployment through a wall of a vessel to create a hemostatic seal around the opening in a vessel wall.
According to one embodiment, the tubular body includes a self-expanding (e.g., longitudinally and/or radially) tubular mesh that is formed of filaments. The filaments terminate at a side of the tubular mesh and are coupled at the hub. The tubular mesh is formed by an array of cells defined by an interwoven pattern. This tubular mesh may be formed from a metal such as stainless steel or a shape-set memory material such as Nitinol. The pattern array may also either be symmetrical about the central axis, or asymmetrical with a hemi-cylindrical region with a differing array of cells, or a woven structure.
The hub is movable relative to the tubular mesh. The filaments terminating at the hub extend at a non-zero angle with respect to an central longitudinal axis through the tubular body. The angle may be between 0 degrees and 180 degrees. The hub includes a connecting structure to removably the implant from a deployment device.
In one embodiment, a tether surrounds the tubular body or is otherwise coupled to the implant to retain the tubular body in a radially collapsed configuration during deployment of the implant completely through the wall of the vessel and to the deployment site within the vessel. The tether may be released from a proximal end of the deployment device to permit the tubular body of the implant to self-expand within the vessel. In one embodiment, the tether can be locked to a “spring” in the system that can allow for the tether to be displaced while maintaining tension without the tether being released.
The hemostatic or occlusive material is provided to the mesh at least about a circumferential portion suitable for creating a hemostatic seal about an opening in a vessel wall. The hemostatic or occlusive material may be formed of materials such as, but not limited to, PTFE and Dacron, which may be affixed to the outer or inner circumference of the mesh of the tubular body. In an embodiment, the hemostatic or occlusive material is a sealing fabric longer in width (circumferential dimension) than in length (axial or longitudinal dimension) and is sized to seal over the aperture of the punctured vessel. The sealing fabric is configured to promote clot formation, fill in vessel openings, and conform to irregular surfaces. Preferably, such a sealing fabric covers only a partial region of the mesh of the tubular body preventing any flow-through of fluids on only that covered region. Another occlusive material that can be used alone or in combination with the sealing fabric is a urethane coating coated on the tubular mesh. For example, according to one embodiment, a partial region of the tubular mesh may be dip coated in a liquid urethane to provide an even coating of urethane to the tubular mesh that extends within the cells of the mesh of the partial region. The urethane coating can provide additional hemostasis and facilitate sealing of the vessel puncture.
The purpose of the occlusive region is the selective and asymmetric hemostasis of solely the region of the vessel adjacent to the occlusive or hemostatic material. The uncovered region of the tubular body primarily functions as a stabilization and radial force-generating region only; it has no hemostatic or occlusive function. The uncovered section may also be formed from a horizontally discontinuous set of looped cell arrays, further reducing the profile and size of the structure.
According to one embodiment, the covered region may be further extended beyond the midline with the uncovered region removed, forming a “C-like” shape where there is a vertically discontinuous section that still retains enough radial force at the extremities to anchor in the lumen. For example, in at least one embodiment, the body of the implant may take the form of a portion of a cylinder, such as a hemi-cylinder.
According to one embodiment, an attachment site is located approximately at a central midpoint (between the longitudinal spaced ends of the mesh body) on the outer circumference of a hemi-cylindrical covered portion of the structure. This portion can have a circular metallic or metal-like hub affixed to it, providing central structural integrity and an attachment site for the mesh filaments. This hub structure may have a central self-closing opening for the passage of a guidewire or other device. In addition, the entire implant according to this embodiment may flex and/or pivot about the hub. A crimp may be provided to secure the hub over the filaments.
As noted hereinabove, the hub may also include a connecting structure for attachment of a distal end of a deployment device for delivering and deploying the implant. One connecting structure includes threads. Another connecting structure includes a bayonet locking structure. The hub may extend outwards providing a cylindrical or knob-like portion that provides additional anchoring and stability. This region has a pre-defined length and is to be seated within a natural or intentionally formed conduit such as a Caval-Aorto fistula. The hub may also be other shapes, such as disc-shaped or other flat-shaped. All shapes can apply a clamping force upon the vessel wall.
The tubular mesh is configured with a radially-expanding bias. The tubular mesh can be radially collapsed and constrained against its self-expanding bias. The aforementioned tether is configured to retain the tubular mesh in a collapsed configuration for delivery. The tether may extend around the circumference of the tubular mesh to constrain it in the collapsed configuration. The tether may extend around the exterior, or through one or more openings formed in the tubular body that may facilitate securing the tether relative to the implant during a deployment procedure. In one embodiment, the collapsed and tethered implant is configured to be loaded into a delivery catheter (i.e. vascular sheath) of a delivery system for deployment in a packaged configuration. In its compressed and packaged configuration, the implant will maintain a smaller profile than in the uncompressed, expanded configuration, allowing for smoother navigation and deployment of the implant in the vessel.
The delivery system also includes a shaft advanceable within the delivery catheter and that can be coupled at its distal end to the hub, such as via a threaded connection or complementary bayonet structure, and actuated, e.g., rotated or linearly actuated, via the proximal end of the delivery system. The shaft is preferably sufficiently flexible such that it can be advanced intravascularly without injury to the patient. The shaft is preferably sufficiently longitudinally stiff such that it can advance the tubular mesh through the delivery catheter and into the vessel without buckling. The shaft is preferably torsionally stiff such that it can transfer rotational force applied at the proximal end of the shaft to the distal end of the shaft, in as near a 1:1 ratio as practicable. Longitudinal displacement of the shaft relative to the delivery catheter permits manipulation of the implant relative to the target vessel. Rotation of the shaft relative to the implant results in release of the implant from the shaft.
In one embodiment, two ends of the tether extend through the delivery catheter and out of the proximal end of the delivery catheter. Once the implant is at the target location, one of the ends of the tether can be released and the other end of the tether can be withdrawn from the delivery catheter to cause the tether to be released from about the implant and withdrawn to permit the tubular body of the implant to expand within the vessel.
In one embodiment, the tether may have release knots or clips at some point along the implant that will allow for an end of the tether to be released to allow the frame to expand when the knots are untied. In this embodiment, the ends of the tether need not be located outside of the delivery catheter.
In one embodiment, the body of the implant retains its cylindrical shape while compressed within the delivery tube or catheter so that the outer circumference of the body is flush with the inner wall of the catheter. In this embodiment the tether extends in a plane perpendicular to the central axis of the body and the hub is pivoted so that it is parallel with the central longitudinal axis. In addition, the uncovered region is constricted circumferentially to lower the profile size further. Deployment of this embodiment of the implant relies on the advancement of the structure via the tether out of the delivery tube or catheter into the vessel lumen. As the implant leaves the catheter, the hub will gradually adjust its angle until the tubular body of the implant is concentric with the lumen of the vessel.
An additional packaged configuration of the implant is collapsed about the central hub of the implant while the tether is wrapped above the hub and above a center line (midpoint between the first and second ends of the body) of the body. Tension in the tether can be used to control the rotational bias of the body about the hub as the body expands upon its introduction into a vessel. Specifically, a user can control the tension in the tether to adjust the angle of the body pivoting about the hub, which is coupled to the deployment device. Therefore, by adjusting the tension in the tether, a user can control the angle of the body of the implant as the body expands inside the vessel.
Additionally, the tubular body of the implant is configured to expand to a tubular shape that is generally concentric within the vessel, but is at a diameter that is smaller than the vessel and then is able to expand by a user's control of the tether or an equivalent type method. Alternatively, a balloon expanded stent system can be used.
In one embodiment, the construction and pattern of a tubular mesh composed of woven wires can be arranged such that the volume required during expansion does not interfere with the vessel and, therefore, allows the structure to articulate and self-align concentrically within vessel. The woven wires can be arranged such that each strand has two free ends culminating into the central hub.
In one embodiment, a woven pattern of the tubular mesh can be created using a single wire to create the entire woven structure, with only the two ends of the wire within the hub. In yet another embodiment, the tubular mesh does not contain interwoven wires but contains a vertical array of angulating wires in a tubular arrangement. In a further embodiment, the tubular mesh is created from a single wall tube that is laser cut to create an array of diamond like patterns that are able to flatten to allow the overall tubular diameter to reduce or increase.
Additionally, individual loops of metallic wire can be used to support the hemostatic sealing structure against the vessel.
In an additional embodiment, a plurality of tubular mesh structures are linked together to seal multiple vessels in a sequential fashion.
Bioabsorbable materials can be used both for the tubular mesh structure and for the hemostatic and occlusive portion.
As an alternate to a tether that surrounds or is otherwise coupled to the implant to retain the implant in a radially collapsed configuration, a single clip or multiple clips can be used to maintain the implant in a radially collapsed configuration. The clip can be part of the delivery system and housed in proximity to the hub. The implant can be collapsed radially and loaded into the clips at points along its circumference. The user can actuate the handle to release the clips and permit the implant to self-expand within the vessel.
Also, while the hub structure is disclosed as having a central self-closing opening for the passage of a guidewire or other device, as an alternative a portion of the frame can be arranged such that it allows for the passage of devices once interrogated. A self-closing hinged or flexing gate can be used to facilitate device passage and immediate closing once retrieved.
Although the implant is illustrated and described herein as embodied in systems and methods of multi-vessel closure, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit and scope of this disclosure. By way of example, the structure of the individual occluders, alone or in combination with the deployment systems taught herein, can be used to seal and provide hemostasis at an aperture in a single tissue wall, including in a vessel, or in the wall of an organ, such as the heart, and more particularly, by way of example only, to treat atrial septal defects. Additionally, well-known elements of exemplary embodiments of the invention will not be described in detail or will be omitted so as not to obscure the relevant details of the invention.
Additional features are set forth in the detailed description that follows and may be apparent from the detailed description or may be learned by practice of exemplary embodiments. Other features and attendant benefits may be realized by any of the instrumentalities, methods, or combinations particularly pointed out in the present disclosure.
In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which are shown by way of illustration embodiments that may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope.
The terms “comprises,” “comprising,” or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “comprises . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element. The terms “including” and/or “having,” as used herein, are defined as comprising (i.e., open language). The terms “a” or “an”, as used herein, are defined as one or more than one. The term “plurality,” as used herein, is defined as two or more than two. The term “another,” as used herein, is defined as at least a second or more. The description may use the terms “embodiment” or “embodiments,” which may each refer to one or more of the same or different embodiments.
The terms “coupled” and “connected,” along with their derivatives, may be used. It should be understood that these terms are not intended as synonyms for each other. Rather, in particular embodiments, “connected” may be used to indicate that two or more elements are in direct physical or electrical contact with each other. “Coupled” may mean that two or more elements are in direct physical or electrical contact (e.g., directly coupled). However, “coupled” may also mean that two or more elements are not in direct contact with each other, but yet still cooperate or interact with each other (e.g., indirectly coupled).
For the purposes of the description, a phrase in the form “A/B” or in the form “A and/or B” or in the form “at least one of A and B” means (A), (B), or (A and B), where A and B are variables indicating a particular object or attribute. When used, this phrase is intended to and is hereby defined as a choice of A or B or both A and B, which is similar to the phrase “and/or”. Where more than two variables are present in such a phrase, this phrase is hereby defined as including only one of the variables, any one of the variables, any combination of any of the variables, and all of the variables, for example, a phrase in the form “at least one of A, B, and C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C).
Relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The description may use perspective-based descriptions such as up/down, back/front, and top/bottom. Such descriptions are merely used to facilitate the discussion and are not intended to restrict the application of disclosed embodiments. Various operations may be described as multiple discrete operations in tum, in a manner that may be helpful in understanding embodiments; however, the order of description should not be construed to imply that these operations are order dependent.
As used herein, the term “about” or “approximately” applies to all numeric values, whether or not explicitly indicated. These terms generally refer to a range of numbers that one of skill in the art would consider equivalent to the recited values (i.e., having the same function or result). In many instances these terms may include numbers that are rounded to the nearest significant figure.
Herein various embodiments of the systems and methods are described. In many of the different embodiments, features are similar. Therefore, to avoid redundancy, repetitive description of these similar features may not be made in some circumstances. It shall be understood, however, that description of a first-appearing feature applies to the later described similar feature and each respective description, therefore, is to be incorporated therein without such repetition.
As used herein, terms such as transcaval, TCA, TC, trans-caval, caval-aortic, aortocaval, aorto-caval, venous-arterial are the same. Terms such as aperture, opening, rent when used herein are the same. Terms such as tract, shunt, path when used herein are the same. Terms such as vessel, vessels, wall, walls, tissue, tissue wall, tissue walls, aortic vessel wall, venous vessel wall when used herein are the same.
The tubular body 1 is shown in
As shown in
The implant 100 is configured to be compressed radially and axially for deployment into a substantially linear delivery configuration and loaded into a hollow deployment tube 20, forming an assembly 25 as shown, for example, in
As shown in
As shown in
Once the body 1 is fully expanded, as shown in
The hub 116 is configured to connect to any control systems used for the manipulation and deployment of the implant 110. The hub 116 is movably (e.g., pivotally) coupled to the tubular mesh 114 with an eyelet 118 (
As shown in
The implant 110 and deployment device 132 are configured for use in a transcaval procedure, illustrated in
With reference to
There have been described and illustrated herein several embodiments of an implant and a method of using the implant. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. Thus, while particular configurations of the body of the implant have been disclosed, it will be appreciated that other structures having similar properties to those disclose may be used as well. In addition, while particular types of materials have been disclosed, it will be understood that other materials having similar properties to those disclosed can be used. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as claimed.
This application claims priority under 35 U.S.C. 119(e) to U.S. Provisional Applications 62/437979, filed Dec. 22, 2016, and 62/579674, filed Oct. 31, 2017, the entire contents of all of which are incorporated herein by reference. Also, this application is related to U.S. application Ser. No. 15/060,960, filed Mar. 4, 2016, the entire contents of which are incorporated herein by reference.
Number | Date | Country | |
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62437979 | Dec 2016 | US | |
62579674 | Oct 2017 | US |