Dual tissue wall anchoring mechanism sharp stent

Abstract

The present invention relates to a system and method for creating channels between tissue walls of various thicknesses using stents. The stent includes an elongate body (100) having a restrained position and an expanded position, wherein in the expanded position, a proximal portion (110) of the body expands into a proximal retention member (112), a distal portion (120) expands into a distal retention member (122), and a cylindrical saddle region (130) extends between the proximal and distal retention members. The proximal retention member, the distal retention member, and the cylindrical saddle region can form an open internal passage (140) configured to allow flow therethrough. The proximal retention member can include first and second flanges (114, 116) spaced apart by a first distance (W1), and the distal retention member can include third and fourth flanges (124, 126) spaced apart by a second distance (W2), the first distance being greater than the second distance.

Description

Technical Field

[0001] The present invention generally relates to the field of body lumen drainage. In particular, the present invention relates to a system and method for forming a flow path opened between tissue walls of various thicknesses.

Background Art

[0002] Discharging body fluid from within a living body or other sites through a transcutaneously formed path to a collection location outside the body can be accompanied by difficulties. For example, bile is a yellowish-brown liquid secreted by the liver and is sent through the bile duct to the small intestine to aid in lipid digestion. Due to bile duct obstruction, bile may accumulate in the body, resulting in physical symptoms such as jaundice, itching, and dark urine. Percutaneous transhepatic biliary drainage is a medical procedure usually performed when surgical treatment or endoscopic treatment has failed, and a flexible plastic tube or self-expanding stent is inserted into the bile duct by piercing the patient's skin in order to discharge bile to the outside of the body or to a collection bag outside the small intestine. Such procedures tend to be accompanied by various delayed medical complications such as bile leakage around the insertion site, damage to the tissue wall anchoring site, movement of the tube, detachment of the tube, and / or blockage of the tube.

Summary of the Invention

[0003] In particular, in the field of minimally invasive devices and minimally invasive procedures for forming a flow path opened between tissue walls of various thicknesses, by the system and / or method of the present invention that can suppress movement of a stent and reliably anchor it to tissue walls of various thicknesses while minimizing tissue damage, various excellent medical effects can be realized.

[0004] In one embodiment, the present invention relates to a stent comprising an elongated body having a constrained position and an expanded position, wherein in the expanded position, the proximal portion of the body expands to a proximal retaining member, and the distal portion expands to a distal retaining member, with a cylindrical saddle region extending between the proximal and distal retaining members. The proximal retaining member, the distal retaining member, and the cylindrical saddle region may form an open internal passage configured to allow flow through. The proximal retaining member may include first and second flanges spaced a first distance apart from each other, and the distal retaining member may include third and fourth flanges spaced a second distance apart from each other, wherein the first distance is greater than the second distance. The proximal retaining member, the distal retaining member, and the cylindrical saddle region may be formed from a woven material. The proximal and distal retaining members may be formed from a woven material, and the cylindrical saddle region may be formed from a knitted material. The proximal and distal retaining members may be formed from a woven material, and the cylindrical saddle region may be formed from a polymer material. The proximal and distal retaining members may be formed from a polymer material, and the cylindrical saddle region may be formed from a woven material. The proximal retaining members, distal retaining members, and / or cylindrical saddle region may be coated. The polymer material may be biodegradable or biodegradable. The second and third flanges may be spaced apart by a third distance, the third distance being greater than the first distance. The first, second, third, and fourth flanges may extend perpendicular to the outer circumference of the elongated body. The diameters of the first, second, third, and fourth flanges may be larger than the diameter of the cylindrical saddle region. The first and second flanges may be configured to contact opposing sides of the first tissue layer, and the third and fourth flanges may be configured to contact opposing sides of the second tissue layer. A valve may be positioned within the open internal passage of the elongated body.

[0005] In other embodiments, the present invention relates to a stent comprising a stent body formed of a filament woven material, the stent body having a constrained position and an expanded position, in which the proximal portion of the body expands to a proximal retaining member and the distal portion expands to a distal retaining member, with a cylindrical saddle region extending between the proximal and distal retaining members. The proximal retaining member, the distal retaining member and the cylindrical saddle region can be covered. The proximal retaining member, the distal retaining member and the cylindrical saddle region can form an open internal passage configured to allow flow through. The proximal retaining member may include first and second flanges spaced a first distance apart from each other, and the distal retaining member may include third and fourth flanges spaced a second distance apart from each other, wherein the first distance is greater than the second distance. The second and third flanges may be spaced a third distance apart, wherein the third distance is greater than the first distance. The first, second, third, and fourth flanges may extend perpendicular to the outer circumference of the stent body. The diameters of the first, second, third, and fourth flanges may be larger than the diameter of the cylindrical saddle region. The first and second flanges may be configured to contact opposing sides of the first tissue layer, and the third and fourth flanges may be configured to contact opposing sides of the second tissue layer. A valve may be positioned within the open internal passage of the stent body.

[0006] In other embodiments, the present invention relates to a stent comprising an elongated body having a constrained position and an expanded position, wherein in the expanded position, the proximal portion of the body expands to a proximal retaining member, and the distal portion expands to a distal retaining member, with a cylindrical saddle region extending between the proximal and distal retaining members. The proximal and distal retaining members may be formed of a woven material, and the cylindrical saddle region may be formed of a knitted material. The proximal retaining member, the distal retaining member, and / or the cylindrical saddle region may be covered. The proximal retaining member, the distal retaining member, and the cylindrical saddle region may form an open internal passage configured to allow flow through. The proximal retaining member may include first and second flanges spaced a first distance apart from each other, and the distal retaining member may include third and fourth flanges spaced a second distance apart from each other, wherein the first distance is greater than the second distance. The second and third flanges may be spaced apart by a third distance, the third distance being greater than the first distance. The first, second, third, and fourth flanges may extend perpendicular to the outer circumference of the elongated body. The diameters of the first, second, third, and fourth flanges may be greater than the diameter of the cylindrical saddle region. The first and second flanges may be configured to contact opposing sides of the first tissue layer, and the third and fourth flanges may be configured to contact opposing sides of the second tissue layer. A valve may be positioned within the open internal passage of the elongated body.

[0007] In yet another embodiment, the present invention relates to a stent comprising an elongated body having a constrained position and an expanded position, wherein in the expanded position, the proximal portion of the body expands to a proximal retaining member, and the distal portion expands to a distal retaining member, with a cylindrical saddle region extending between the proximal and distal flanges. The proximal and distal retaining members may be formed of a woven material, and the cylindrical saddle region may be formed of a polymer material. The proximal and / or distal retaining members may be covered. The proximal and distal retaining members and the cylindrical saddle region may form an open internal passage configured to allow flow through. The proximal retaining member may include first and second flanges spaced a first distance apart from each other, and the distal retaining member may include third and fourth flanges spaced a second distance apart from each other, wherein the first distance is greater than the second distance. The second and third flanges may be spaced apart by a third distance, the third distance being greater than the first distance. The first, second, third, and fourth flanges may extend perpendicular to the outer circumference of the elongated body. The diameters of the first, second, third, and fourth flanges may be greater than the diameter of the cylindrical saddle region. The first and second flanges may be configured to contact opposing sides of the first tissue layer, while the third and fourth flanges may be configured to contact opposing sides of the second tissue layer. A valve may be positioned within the open internal passage of the stent body. The cylindrical saddle region may include an internal support structure or an external support structure. The cylindrical saddle region may include one or more corrugated sections.

[0008] In yet another embodiment, the present invention relates to a stent comprising an elongated body having a constrained position and an expanded position, wherein in the expanded position, the proximal portion of the body expands to a proximal retaining member, and the distal portion expands to a distal retaining member, with a cylindrical saddle region extending between the proximal and distal flanges. The proximal and distal retaining members may be formed of a polymer material, and the cylindrical saddle region may be formed of a woven material. The cylindrical saddle region may be covered. The proximal retaining member, the distal retaining member, and the cylindrical saddle region may form an open internal passage configured to allow flow through. The proximal retaining member may include first and second flanges spaced a first distance apart from each other, and the distal retaining member may include third and fourth flanges spaced a second distance apart from each other, wherein the first distance is greater than the second distance.

[0009] Non-limiting embodiments of the present invention will be described by reference to the accompanying drawings, which are schematic and not drawn to scale. In the drawings, the same or substantially the same components shown are usually represented by the same number. For clarity, not all components are labeled in all drawings, and not all components of each embodiment are shown where not an example is necessary for those skilled in the art to understand the invention. [Brief explanation of the drawing]

[0010] [Figure 1A] A perspective view of a self-expanding drainage stent according to one embodiment of the present invention. [Figure 1B] A perspective view of a self-expanding drainage stent according to one embodiment of the present invention. [Figure 1C] A perspective view of a self-expanding drainage stent according to one embodiment of the present invention. [Figure 1D] A perspective view of a self-expanding drainage stent according to one embodiment of the present invention. [Figure 1E]A perspective view of a self-expanding drainage stent according to one embodiment of the present invention. [Figure 1F] A perspective view of a self-expanding drainage stent according to one embodiment of the present invention. [Figure 2] A perspective view of the self-expanding drainage stent shown in Figure 1A, which is placed inside a patient's body according to one embodiment of the present invention. [Modes for carrying out the invention]

[0011] The present invention is not limited to the specific embodiments described herein. The terms used herein are for illustrative purposes only to describe specific embodiments and do not limit the scope beyond the scope of the appended claims. Unless otherwise specifically defined, all technical terms used herein have the same meaning as those generally understood by those skilled in the art to which the present invention pertains.

[0012] While embodiments of the present invention are described with particular reference to medical devices and systems for biliary drainage, such medical devices may be used to secure and / or maintain temporary or permanent open channels between various biological organs, lumens, and body cavities, such as the dermis, stomach, duodenum, kidney, and gallbladder. These devices can be inserted by a variety of different access points and approaches, such as percutaneous, endoscopic, laparoscopic, or any combination thereof. The stents described are self-expanding, but other embodiments may be possible in which the stent can be expanded by other means, such as a balloon catheter. Furthermore, such medical devices may facilitate access to organs for purposes other than drainage, such as removal of obstructions and the performance of treatment, which may include non-invasive or minimally invasive manipulation of tissue within the organ and / or introduction of drugs via the open channel.

[0013] As used herein, the singular forms "a," "an," and "the" also include the plural form unless otherwise explicitly indicated in the context. Furthermore, as used herein, the expressions "comprises" and / or "comprising" or "includes" and / or "include" specify the presence of the described features, areas, steps, elements, and / or components, but do not exclude the presence or addition of one or more other features, areas, integer values, steps, operations, elements, components, and / or groups thereof.

[0014] As used herein, the term “distal” refers to the end furthest from the healthcare professional when the device is introduced to the patient, while the term “proximal” refers to the end closest to the healthcare professional when the device is introduced to the patient.

[0015] In one embodiment, the present invention relates to a self-expanding drainage stent configured to extend between separate tissue layers. Referring to Figure 1A, in one embodiment, the drainage stent of the present invention may include an elongated body 100 formed of a filament woven material, filament knitted material, or filament knitted material (e.g., nitinol) and configured to transition between a constrained position and an expanded position. In the expanded position, the proximal portion 110 of the elongated body 100 can form a proximal retaining member 112 having first and second flanges 114, 116, and the distal portion 120 of the elongated body 100 can form a distal retaining member 122 having third and fourth flanges 124, 126, with a cylindrical saddle region 130 extending between the proximal and distal retaining members. The proximal retaining member, distal retaining member, and / or cylindrical saddle region may include a coating 142 on its inner and / or outer surfaces to form a continuous open internal passage 140 configured to allow a flow (e.g., bodily fluids, substances, etc.) to pass through. The coating 142 may consist of a variety of polymer materials that are non-degradable and biocompatible (when exposed to bodily fluids such as bile), such as silicone, rubber, polyethylene, PVDF (polyvinylidene fluoride), Chronoflex®, and thermoplastic elastomers. The first and second flanges 114, 116 may be spaced apart by a first distance W1, and the third and fourth flanges 124, 126 may be spaced apart by a second distance W2, wherein the first distance W1 is greater than the second distance W2. The second and third flanges 116, 124 may be spaced apart by a third distance W3 to define the length of the saddle region 130. As a non-limiting example, the first distance W1 could be about 25.0 mm (e.g., at least 15.0 mm, at least 20.0 mm, at least 30.0 mm, at least 35.0 mm, etc.), and the second distance could be about 0.5 mm (e.g., at least 0.25 mm, at least 0.75 mm, at least 1.00 mm, etc.). The third distance W3 could be smaller than the first distance W1 but larger than the second distance W2. For example, the third distance W3 could be about 10.0 mm (e.g., at least 5.0 mm, at least 15.0 mm, etc.).Alternatively, the third distance W3 may be a larger dimension than the first distance W1. For example, the third distance W3 may be about 200.0 mm (e.g., at least 50.0 mm, at least 100.0 mm, at least 150.0 mm, at least 250.0 mm, etc.). Each of the first flange 114, the second flange 116, the third flange 124, and the fourth flange 126 may extend perpendicular to the outer circumference of the elongated body 100 so as to define planes 114a, 116a, 124a, and 126a, respectively. In various embodiments, the first flange, the second flange, the third flange, and the fourth flange may have various configurations so that one or more of the flanges extend radially at an angle not necessarily perpendicular to the elongated body, and further / or the planes 114a, 116a, 124a, and / or 126a are not necessarily flat. For example, any or all of the first flange, second flange, third flange, and fourth flange may be oriented outward toward the end of the elongated body, or toward the center of the elongated body, or in any combination of both.

[0016] In various embodiments, the first distance W1 may be sufficient to bring the planes 114a, 116a of the first and second flanges 114, 116 into contact with the opposing sides of a first tissue wall, such as the abdominal wall, and compress (e.g., engage) them strongly. The second distance W2 may be sufficient to bring the planes 124a, 126a of the third and fourth flanges 124, 126a into contact with the opposing sides of a second tissue wall, such as the bile duct, and compress (e.g., engage) them strongly. One or more of the planes 114a, 116a, 124a, 126a may further have a surface pattern (e.g., bumps, projections, spherical projections, etc.) arranged in various random or non-random patterns to engage with the corresponding tissue wall, thereby restricting or preventing the stent from moving (e.g., rotating) within or between tissue walls. The third distance W3 may be sufficient to allow the cylindrical saddle region to extend between the first and second tissue walls so as to provide an open internal passage between the first and second tissue walls without exerting excessive tension on or between either tissue wall. In one embodiment, the portion of the elongated body 100 forming the cylindrical saddle region 130 may be configured not to shorten when either the proximal or distal retaining member is implanted, thereby minimizing the tension applied between the first and second tissue walls. Each of the first flange 114, the second flange 116, the third flange 124, and the fourth flange 126 may have an outer diameter d1 that is larger than the outer diameter d2 of the portion of the cylindrical saddle region and / or the portion of the proximal retaining member 112 and the distal retaining member 122 between flanges 114, 116, 124, and 126, respectively. For example, the outer diameter d1 may be approximately 7.0 mm to approximately 30 mm, and the outer diameter d2 may be approximately 3.0 mm to approximately 15.0 mm. For example, in one or more embodiments, one or more of the first flange 114, the second flange 116, the third flange 124, and the fourth flange 126 may have an outer diameter d1 that is 75% to 100% larger than the outer diameter d2 of the portion between the flanges 114, 116, 124, and 126 of the cylindrical saddle region and / or the proximal retaining member 112 and the distal retaining member 122, respectively.

[0017] Referring to Figure 1B, in one embodiment, the first portion 110 and the second portion 120 of the elongated body 100 may be formed from a filament woven material or filament braid (e.g., nitinol) configured to form the proximal retaining member 112 and the distal retaining member 122 as described above, and the cylindrical saddle region 130 may be formed from a filament braid (e.g., nitinol). Compared to a filament woven material or filament braid, the filament braid can impart greater flexibility to the cylindrical saddle region, thereby reducing the possibility of one or both retaining members detaching or otherwise applying excessive force to either tissue wall when the patient moves. In one embodiment, each end of the cylindrical saddle region 130 may be attached (e.g., bonded, joined, woven, or glued) to the proximal portion 110 and the distal portion 120 using a suitable glue, adhesive, resin, or other bonding technique. Alternatively, to impart greater flexibility to the saddle region, the weave pattern of the cylindrical saddle region can be made different from that of the proximal and distal portions. For example, the weave pattern and / or weave pitch of the saddle region can be adjusted as needed to achieve the desired flexibility.

[0018] Referring to Figure 1C, in one embodiment, the first portion 110 and the second portion 120 of the elongated body 100 may be formed from a filament woven material or filament braid (e.g., nitinol) configured to form the proximal retaining member 112 and the distal retaining member 122 as described above, and the cylindrical saddle region 130 may be formed from a polymer material (e.g., polyethylene terephthalate (PET), silicone, thermoplastic shape memory resin and / or thermosetting shape memory resin). Alternatively, a portion of the cylindrical saddle region may be formed from a polymer material, and the other portion of the cylindrical saddle region may be formed from a filament woven material, filament braid, or filament braid. In various embodiments, the polymer material may impart sufficient flexibility or malleability to the cylindrical saddle region or a portion thereof so that the proximal and distal retaining members can engage with misaligned openings in the tissue wall without exerting excessive pressure or strain on either tissue wall. Additionally or alternatively, to enhance the flexibility provided between the proximal and distal retaining members, the cylindrical saddle region may include various internal or external support structures (e.g., helical support structures, spiral support structures, corrugated sections, etc.).

[0019] Referring to Figure 1D, in one embodiment, the proximal 110 and distal 120 of the elongated body 100 may be formed of a polymer material (e.g., polyethylene terephthalate (PET), silicone, thermoplastic shape memory resin and / or thermosetting shape memory resin) configured to form the proximal retaining member 112 and the distal retaining member 122, and the cylindrical saddle region 130 may be formed of a filament fabric or filament braid (e.g., nitinol).

[0020] In various embodiments, the polymer material may include a biodegradable or biodegradable material configured to allow the proximal retaining member and / or distal retaining member to partially or completely decompose over time, so that the stent is released from the first and second tissue walls without requiring surgical intervention. In any of the embodiments shown in Figures 1C to 1D, the filamentary fabric or filamentary braid may be attached to the polymer material using a suitable glue, adhesive, resin, or other bonding technique. Additionally or alternatively, in any of the various embodiments, the filamentary braid may be a metal filament or a polymer filament, and may further include a woven single filament or a woven multifilament.

[0021] Referring to Figure 1E, in one embodiment, the open internal passage 140 of the elongated body 100 may further include one or more valves 150 (e.g., a duckbill valve, a slit valve, etc.) that can transition between a closed and open state, thereby blocking or preventing fluid flow through the open internal passage 140 until the patient or medical professional determines that the valve should be opened (e.g., by inserting a drainage tube). Although the valve 150 is shown within the scope of the first retaining member 112, in various embodiments the valve 150 may be located anywhere along the open internal passage 140 of the elongated body 100. An example of such a valve is described in U.S. Patent Application Publication No. 2012 / 0226243, the contents of which are incorporated herein by reference in their entirety. Such a valve may be made of a variety of suitable biocompatible and non-degradable materials, such as any of the polymers considered herein, and may be used in conjunction with any of the various embodiments described or any other embodiments contemplated within the scope of the invention.

[0022] Referring to FIG. 1F, in one embodiment, the first and second flanges 114, 116 of the proximal retaining member of the elongated body 100 can be separated by a first distance W1, and the third and fourth flanges 124, 126 of the distal retaining member can be separated by a second distance W2, and the first distance and the second distance are substantially the same. The second and third flanges 116, 124 can be separated by a third distance W3 so as to define the length of the saddle region 130. For example, both the first distance W1 and the second distance W2 can be about 0.5 mm (e.g., at least 0.25 mm, at least 0.75 mm, at least 1.00 mm, etc.). In various embodiments, the first distance W1 can be a distance sufficient to strongly compress (e.g., engage) by contacting the planes 114a, 116a of the first and second flanges 114, 116 against opposite sides of a first tissue wall, such as the duodenal wall. The second distance W2 can be a distance sufficient to strongly compress (e.g., engage) by contacting the planes 124a, 126a of the third and fourth flanges 124, 126 against opposite sides of a second tissue wall, such as the bile duct. The third distance W3 can be a distance sufficient for the cylindrical saddle region to extend between the first tissue wall and the second tissue wall, and the cylindrical saddle region provides an open internal passage between the first tissue wall and the second tissue wall without exerting an undesirable tension on both the first tissue wall and the second tissue wall, i.e., between both tissue walls. In various embodiments, the first flange, the second flange, the third flange, and the fourth flange can have various configurations, whereby one or more of these flanges extend radially at an angle that is not necessarily perpendicular to the elongated body, and / or the planes 114a, 116a, 124a, and / or 126a are not necessarily flat. For example, any or all of the first flange, the second flange, the third flange, and the fourth flange can extend outwardly toward the end of the elongated body, or return toward the central portion of the elongated body, or change direction in some combination of both of these, and extend.

[0023] Referring to FIG. 2, in one embodiment, the drainage stent 100 of the present disclosure is disposed in the patient's body such that the planes 114a, 116a of the first and second flanges 114, 116 contact (e.g., engage) opposite sides of the abdominal wall 60, the planes 124a, 126a of the third and fourth flanges 124, 126 contact opposite sides of the bile duct 70, and the cylindrical saddle region 130 extends between the abdominal wall and the bile duct to provide an internal passageway open between the abdominal wall and the bile duct.

[0024] In use, by way of example, the drainage stent can be disposed in the lumen of the tissue piercing element in a constrained position. The sharp distal end of the tissue piercing element can be advanced through the abdominal wall into the internal region of the bile duct. Next, the distal portion 120 of the stent body 100 can be advanced distally beyond the lumen of the tissue piercing element, whereby the fourth flange 126 is retained within the bile duct and its plane 126a is brought into contact with the inner wall of the bile duct. Next, the tissue piercing element is retracted proximally such that its sharp distal end is disposed outside the bile duct, and the remaining distal portion 120 of the elongated body is advanced distally beyond the lumen of the tissue piercing element, whereby the third flange 124 is retained outside the bile duct and its plane 124a is brought into contact with the outer wall of the bile duct.

[0025] Once the placement of the distal retaining member is complete, the tissue piercing member can be retracted proximally such that its sharp distal end is disposed adjacent to the inner surface of the abdominal wall. Next, the proximal portion 110 of the stent body 110 can be advanced distally beyond the lumen of the tissue piercing element, whereby the second flange is retained such that its plane 116a contacts the inner abdominal wall. Next, the tissue piercing element can be retracted proximally such that its sharp distal end is disposed outside the patient's body, and the remaining proximal portion 110 of the elongated body is advanced distally beyond the lumen of the tissue piercing element, whereby the first flange is retained such that its plane 114a contacts the outer abdominal wall.

[0026] Alternatively, in the above method, a separate instrument having a sharp distal tip can be advanced into the bile duct along the above route, thereby securing the route and introducing a guidewire. The separate instrument is then withdrawn along the guidewire, and a drainage stent according to the various embodiments described above is attached to the delivery catheter inserted along the guidewire. Subsequently, the stent is placed according to the steps outlined above.

[0027] In various embodiments, a medical device (e.g., a retrieval bag) may be attached to the portion of the stent body 100 that extends outside the patient's body. Additionally or alternatively, various medical devices may be inserted through the open internal passage formed by the stent body in its expanded position. For example, a drainage tube may be advanced through the open internal passage to facilitate the drainage of fluid passing through it. Alternatively, an extraction device may be introduced through the open internal passage to remove an obstruction (e.g., a gallstone) from the bile duct.

[0028] (Note) As a preferred embodiment, the technical concept that can be understood from the above embodiment is described below. [Item 1] It is a stent, It has an elongated body that is in a restrained position, The elongated body has an expanded position, in which the proximal portion of the elongated body is expanded to become a proximal holding member, the distal portion of the elongated body is expanded to become a distal holding member, and a cylindrical saddle region of the elongated body extends between the proximal holding member and the distal holding member. The proximal holding member, the distal holding member, and the cylindrical saddle region form an open internal passage configured to allow flow through. The cylindrical saddle region is constructed of a different material, weave pattern, knit pattern, weave pitch, knit pitch, or braid pitch, or any combination thereof, compared to one or both of the proximal and distal retaining members, so as to provide greater flexibility to the cylindrical saddle region compared to one or both of the proximal and distal retaining members. A stent comprising a proximal retaining member including a first flange and a second flange spaced apart by a first distance, and a distal retaining member including a third flange and a fourth flange spaced apart by a second distance. [Item 2] The stent according to item 1, wherein the proximal retaining member, the distal retaining member, and the cylindrical saddle region are formed of a woven material. [Item 3] The stent according to item 1, wherein the proximal retaining member and the distal retaining member are formed of a woven material, and the cylindrical saddle region is formed of a knitted material. [Item 4] The stent according to item 1, wherein the proximal retaining member and the distal retaining member are formed of a woven material, and the cylindrical saddle region is formed of a polymer material. [Item 5] The stent according to item 1, wherein the proximal retaining member and the distal retaining member are made of a polymer material, and the cylindrical saddle region is made of a woven fabric material. [Item 6] The stent according to item 2, wherein the proximal retaining member, the distal retaining member, and the cylindrical saddle region are covered. [Item 7] The stent according to item 3, wherein the proximal retaining member, the distal retaining member, and the cylindrical saddle region are covered. [Item 8] The proximal retaining member and the distal retaining member are covered, the stent as described in item 4. [Item 9] The cylindrical saddle region is covered, as described in item 5. [Item 10] The polymer material is biodegradable, as described in item 5. [Item 11] A stent according to any one of items 1 to 10, wherein the second flange and the third flange are separated by a third distance, and the third distance is greater than the first distance. [Item 12] The stent according to any one of items 1 to 11, wherein the first flange, the second flange, the third flange, and the fourth flange extend perpendicularly to the outer circumference of the elongated body. [Item 13] A stent according to any one of items 1 to 12, wherein the diameters of the first flange, the second flange, the third flange, and the fourth flange are greater than the diameter of the cylindrical saddle region. [Item 14] The stent according to any one of items 1 to 13, wherein the first flange and the second flange are configured to contact the opposing sides of a first tissue layer that can be positioned between the first and second flanges, and the third flange and the fourth flange are configured to contact the opposing sides of a second tissue layer that can be positioned between the third and fourth flanges. [Item 15] The first distance is different from the second distance, and the stent is one of the items 1 to 14. Any apparatus and / or method disclosed herein and described in the claims can be manufactured and performed in light of the present invention without excessive experimentation. Although the apparatus and method of the present invention are described by preferred embodiments, it will be apparent to those skilled in the art that modifications can be applied to the apparatus and / or method described herein, as well as to the steps or sequence of steps of the method, without departing from the concept, spirit, and scope of the present invention. Any such substitutions and modifications by similar entities that are apparent to those skilled in the art will be deemed to be within the spirit, scope, and concept of the present invention as defined in the appended claims.

Claims

1. It is a stent, The stent comprises an elongated body formed of one or more filament woven materials, and the elongated body has a constrained position and an unconstrained position. In the aforementioned unrestrained position, the end portion of the elongated body is expanded to become a first retaining member, and the other end portion of the elongated body is expanded to become a second retaining member. In the aforementioned unrestrained position, the elongated body includes a saddle region, the saddle region extending a first distance between the first retaining member and the second retaining member, The first retaining member, the second retaining member, and the saddle region form an open internal passage. The first retaining member includes a first flange and a second flange spaced apart from each other by a second distance different from the first distance, The second retaining member includes at least a third flange, The first retaining member, the second retaining member, or both retaining members are made of different weaving patterns relative to the saddle region in order to provide high flexibility to the saddle region. The stent comprises the first retaining member, the second retaining member, or a partial covering portion that extends over the saddle region.

2. The stent according to claim 1, wherein the aforementioned partial covering portion extends over the saddle region.

3. The stent according to claim 2, wherein the partial covering portion further extends over the first retaining member.

4. The stent according to claim 2, wherein the partial covering portion further extends over the second retaining member.

5. The stent according to claim 1, wherein the partial covering portion extends over the first holding member.

6. The stent according to claim 2, wherein the aforementioned partial covering portion extends over the second retaining member.

7. The stent according to claim 1, wherein the aforementioned partial covering portion extends over the second retaining member.

8. The stent according to any one of claims 1 to 7, wherein the diameters of the first flange and the second flange are greater than the diameter of the saddle region.

9. The stent according to any one of claims 1 to 7, wherein the first flange and the second flange are configured to contact opposing sides of the first tissue layer.

10. The stent according to any one of claims 1 to 7, wherein the other end portion of the elongated body, extended to the second retaining member, includes the end portion of the elongated body that is opposite to the end portion of the elongated body, extended to the first retaining member.

11. The stent according to any one of claims 1 to 7, wherein the first retaining member, the second retaining member, or the saddle region, or any combination thereof, is made of a polymer material.

12. The stent according to claim 11, wherein the polymer material is biodegradable.

13. The stent according to any one of claims 1 to 7, wherein one or more of the first retaining member, the second retaining member, or the saddle region is made of a knitted material.

14. The stent according to any one of claims 1 to 7, wherein the first distance is longer than the second distance.

15. The stent according to any one of claims 1 to 7, further comprising a valve disposed within the open internal passage of the elongated body.

16. The stent according to any one of claims 1 to 7, wherein the first flange, the second flange, and the third flange have the same shape.

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