Devices, systems, and methods for controlling the position of an implantable device

Abstract

The stent delivery system includes an external shaft and an internal shaft, at least a portion of which extends into the lumen of the external shaft. The internal shaft comprises a stent receiver and a distal tip coupled to the distal end of the internal shaft. The distal tip includes a plurality of hooks positioned adjacent to the proximal end edge of the distal tip. The stent includes one or more tethers positioned along the stent receiver and coupled to a first end region, a second end region, and the first end region of the stent. One or more tethers are configured to engage with a plurality of hooks, thereby coupling the stent to the distal tip. One of the one or more tethers may be activated by a user to move the stent between a first pre-deployed state and a second deployed state.

Description

Technical Field

[0001] The present disclosure generally relates to implantable medical devices and related systems and methods for adjusting access through a passage of a medical device. More particularly, the present disclosure relates to devices, systems, and methods for controlling the position of an implantable device, such as a lumen-apposing device, and for regulating flow through a passage between two non-adherent structures.

Background Art

[0002] Treatment methods for various medical conditions, such as obesity, diabetes, or duodenal ulcers, include bypassing the duodenum or restricting the flow of substances through the duodenum. When treatment requires complete bypass of the duodenum, occlusion of the pylorus (e.g., complete occlusion) may be indicated, and an anastomosis can be created between the stomach and the jejunum. A lumen-apposing device can be placed between the stomach and the jejunum to allow passage of substances (fluids, liquids, chyme, etc.) from the stomach to the jejunum. One problem presented by such devices is preventing movement of the device. Thus, there is a continuing need to provide alternative medical devices, as well as alternative methods for manufacturing and using medical devices.

[0003] The present disclosure relates to devices, systems, and methods for controlling the position of an implantable device, such as a lumen-apposing device, and for regulating flow through a passage between two non-adherent structures. Even more particularly, the present disclosure relates to devices, systems, and methods for controlling the position of an implantable device to prevent movement of the device.

Summary of the Invention

[0004] This summary of the disclosure is provided for the purpose of aiding understanding, and those skilled in the art will understand that various aspects and features of the disclosure may, in some cases, be used individually to their advantage, and in other cases, in combination with other aspects and features. The inclusion or exclusion of elements, components, etc., in this summary is not intended to limit the scope of the claimed subject matter. Therefore, while the disclosure is presented in terms of aspects or embodiments, it should be understood that each aspect may be claimed separately, individually or in combination with the aspects and features of that embodiment or any other embodiment.

[0005] One example of a medical device may include a stent delivery system. The stent delivery system may include an external shaft having a distal end region, an internal surface defining a lumen extending inside it, and an internal shaft extending at least partially into the lumen of the external shaft. The internal shaft has a stent receiving region positioned along its distal end region, and a distal tip coupled to the distal end of the distal end region of the internal shaft, the distal tip having a plurality of hooks located adjacent to the proximal edge of the distal tip.

[0006] The stent may be positioned along a stent receiving region, and the stent has a first end region, a second end region, and a central region located between the first and second end regions, and further has one or more tethers coupled to the first end region of the stent, the one or more tethers being configured to extend from the first end region to the distal tip and to engage with a plurality of hooks, thereby coupling the stent to the distal tip.

[0007] One of one or more tethers may extend proximal to the lumen along the outer surface of the internal shaft, wherein the tether may be configured to be actuated by the user, and the stent may be configured to move between a first, pre-deployment configuration and a second, deployed configuration, and is held in the first, pre-deployment configuration when located within the lumen of the external shaft.

[0008] Alternatively or additionally, in any of the above embodiments, the distal tip may be a cauterizing tip. Alternatively or additionally, in any of the above embodiments, the first end region may include a first flange structure, and the second end region may include a second flange structure.

[0009] Alternatively or additionally, in any of the above embodiments, one or more tethers may include a particular tether configured to be inserted into a first end region of the stent and to form a plurality of loops configured to engage with a plurality of hooks.

[0010] Alternatively or additionally, in any of the above embodiments, a particular tether may include a first end and a second end. The second end is configured to extend proximal within the lumen along the outer surface of the inner shaft.

[0011] Alternatively or additionally, in any of the above embodiments, one of the one or more tethers may be coupled to a ratchet mechanism. The operation of the ratchet mechanism expands the distal end region of the stent.

[0012] Alternatively or additionally, in any of the above embodiments, the first end region of the stent may include a plurality of hooks configured to engage with one or more tethers. Alternatively or additionally, in any of the above embodiments, at least a portion of the stent may be exposed by retracting the external shaft proximal. As the external shaft is retracted proximal, the exposed portion may expand radially outward.

[0013] Alternatively or additionally, in any of the above embodiments, if the external shaft is fully retracted, the stent may be extended to a second deployed position. In this case, the first end region may be positioned adjacent to the first tissue structure, and the second end region may be positioned adjacent to the second tissue structure.

[0014] Alternatively or additionally, in any of the above embodiments, when the stent is in the second deployed position, the internal shaft may be retracted proximally. Then, one or more tethers may detach from the first end region of the stent and be retracted proximally together with the internal shaft.

[0015] Another example of a medical device may include a stent delivery system. The stent delivery system may include an external shaft having a distal end region and an inner surface defining a lumen extending therein, and an internal shaft extending at least partially into the lumen of the external shaft. The internal shaft has a stent receiving region positioned along its distal end region and a distal tip coupled to the distal end of the distal end region of the internal shaft, the distal tip comprising a plurality of hooks located adjacent to its proximal edge. The stent may be positioned along the stent receiving region and has a first end region, a second end region, and a central region located between the first and second end regions, and further comprises one or more tethers coupled to the first end region of the stent, the one or more tethers configured to extend from the first end region to the distal tip and to engage with a plurality of hooks, thereby coupling the stent to the distal tip.

[0016] Alternatively or additionally, in any of the above embodiments, the external shaft may be retracted proximal to the internal shaft so as to expose the first end region of the stent and to allow the first end region of the stent to move from a first pre-deployment position to a second deployed position.

[0017] Alternatively or additionally, in any of the above embodiments, one of the one or more tethers may extend proximal within the lumen along the outer surface of the internal shaft, and the tether may be configured to be actuated by the user.

[0018] Alternatively or additionally, in any of the above embodiments, a proximal force may be applied to the distal end region of the stent by applying force to one of the one or more tethers, resulting in the first end region expanding radially outward.

[0019] Alternatively or additionally, in any of the above embodiments, when the stent is in the second deployed position, the internal shaft may be retracted proximally, and one or more tethers may detach from the first end region of the stent and be retracted proximally together with the internal shaft. Another example is a method for treating a body cavity. This method may include advancing a stent delivery system to a target tissue site. The stent delivery system may include an external shaft having an inner surface defining a distal end region and a lumen extending inward, and an internal shaft at least partially positioned within the lumen of the external shaft. The internal shaft includes a stent receiving region positioned along its distal end region. The stent delivery system includes a distal tip coupled to the distal end of the internal shaft. The distal tip may include a plurality of hooks positioned adjacent to the proximal edge. The stent is positioned along the stent receiving region. The stent has a first end region, a second end region, and a central region located between them. Furthermore, the stent delivery system may include one or more tethers coupled to the first end region. The tethers extend from the first end region toward the distal tip and are configured to engage with a plurality of hooks, thereby coupling the stent to the distal tip. This method may include retracting the external shaft proximal to the internal shaft. This exposes the first end region of the stent, and the first end region can move from its pre-deployment position to a second deployed position. This method may include applying a proximal force to one or more tethers, which applies a proximal force to the first end region of the stent, causing it to expand radially outward. This method may include pulling the outer shaft further proximal to the inner shaft, which exposes the second end region of the stent, and the second end region can move from its pre-deployment position to a second deployed position. This method may include pulling the inner shaft proximal to the inner shaft, which causes one or more tethers to detach from the first end region of the stent and be pulled proximal to the inner shaft.

[0020] Alternatively or additionally, in any of the above embodiments, the first end region of the stent is positioned adjacent to the first tissue structure while applying a proximal force to the first end region, so that the first tissue structure moves proximal to engage with the second tissue structure.

[0021] Alternatively or additionally, in any of the above embodiments, one or more tethers may include a particular tether. The particular tether is configured to be inserted within a first end region of the stent and to form a plurality of loops configured to engage a plurality of hooks.

[0022] Alternatively or additionally, in any of the above embodiments, the first end region includes a first flange structure and the second end region includes a second flange structure. By applying a proximal direction force to the first end region, the first flange structure is configured to have an outer diameter larger than the outer diameter of the second flange structure.

[0023] Alternatively or additionally, in any of the above embodiments, one of the one or more tethers extends proximally within the lumen along the outer surface of the inner shaft. The tether is configured to be actuated by a user.

[0024] The summary of some of the above embodiments is not intended to describe all embodiments or all examples of the present disclosure. The drawings and detailed description to follow illustrate these embodiments more specifically.

[0025] The present disclosure may be more fully understood by considering the following detailed description in connection with the accompanying drawings.

Brief Description of the Drawings

[0026] [Figure 1] Schematic plan view of a schematic catheter. [Figure 2] Schematic partial view of the elongated shaft of the illustrated catheter showing the outer shaft, inner shaft, and distal tip. [Figure 3] Schematic enlarged view of the distal end region of the inner shaft shown as circle 3 in FIG. 2. [Figure 4] Schematic view of a catheter passing through a tissue wall. [Figure 5] Schematic view of a catheter passing partially through a tissue wall and a partially deployed stent. [Figure 6] A schematic diagram of a stent located between two adjacent tissue walls. [Figure 7] A schematic side view of a stent located between the stomach and a portion of the small intestine. [Figure 8] Figure 7 shows a schematic cross-sectional view of a stent located between the stomach and a portion of the small intestine, along line 8-8. [Figure 9] A schematic side view of a stent positioned over an internal shaft connected to a distal tip. [Figure 10] A schematic perspective view of the stent shown in Figure 9, with its first end region deployed and positioned over the internal shaft. [Modes for carrying out the invention]

[0027] This disclosure is applicable to various modifications and alternative forms, specific examples of which are illustrated and described in detail in the drawings. However, it should be understood that this disclosure is not intended to limit itself to any particular embodiment. Rather, it is intended to encompass all modifications, equivalents, and alternatives that fall within the spirit of this disclosure.

[0028] The terms defined below shall apply unless otherwise given in the claims or elsewhere in this specification. Herein, all numerical values ​​are assumed to be modified by the term “approximately,” whether explicitly stated or not. The term “approximately” generally refers to a range of numerical values ​​that a person skilled in the art would consider equivalent to the stated value (i.e., having the same function or result). Often, the term “approximately” may include numerical values ​​rounded to significant figures.

[0029] When specifying a numerical range using endpoints, all numbers within that range are included (for example, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). As used herein and in the attached claims, the singular forms "a," "an," and "the" refer to multiple subjects unless the context explicitly indicates otherwise. As used herein and in the attached claims, the term "or" generally means "and / or" unless the context explicitly indicates otherwise.

[0030] References in this specification to “one embodiment,” “several embodiments,” “other embodiments,” etc., indicate that the described embodiments may include one or more specific features, structures, and / or characteristics. However, such descriptions do not necessarily mean that all embodiments include those specific features, structures, and / or characteristics. Furthermore, if a specific feature, structure, and / or characteristic is described in relation to one embodiment, it should be understood that such feature, structure, and / or characteristic may also be used in relation to other embodiments, whether explicitly stated or not, unless the reverse is explicitly stated.

[0031] In accordance with various principles of this disclosure, implantable devices may be used to control or regulate the size of passages extending across anatomical structures and passing through them. For example, an implantable device may extend across a passage or lumen of the body, where these terms are used interchangeably without intent to limit. A passage or lumen of the body may include, but is not limited to, a portion of a passage or lumen, a passage or lumen between anatomical structures (passages, lumens, cavities, organs, etc.), a passage formed across opposing tissue walls (e.g., for forming an anastomosis), etc. A device may have a passage or lumen passing through it (where these terms are used interchangeably without intent to limit), and such passage or lumen may be used to occlude, block, narrow, close, contract, regulate, or control (these terms and their inflections are used interchangeably without intent to limit). This device may be considered and referred to as an occlusion device, lumen juxtaposition device, anastomosis device, flow regulation device, or flow control device, and these terms and various other substitutes may be used interchangeably herein without intent of limitation.

[0032] It will be understood that the devices, systems, and methods disclosed herein may be used in endoscopic surgery, laparoscopic surgery, and / or open surgery. Preferably, medical professionals may be able to deliver and / or remove the devices endoscopically. Advantageously, the devices and systems disclosed herein may be used in minimally invasive procedures such as transluminal endoscopic surgery with a natural orifice.

[0033] The following detailed description should be read with reference to drawings in which similar elements are numbered the same in different figures. These drawings, which may not be to scale, illustrate the illustrated embodiments and are not intended to limit the scope of the claims.

[0034] Figure 1 shows a schematic plan view of an illustrated stent delivery system 50 including a catheter 10. As shown in Figure 1, the catheter 10 may include an elongated shaft 12 having a distal end 16 and a proximal end 14. The catheter 10 may have a length ranging from about 50 centimeters to 200 centimeters, and its outer diameter (OD) may be less than 3 French. In some cases, the catheter 10 may have an outer diameter of 1.7 French, 2 French, 2.5 French, 2.8 French, or other appropriate outer diameters. In some cases, the catheter 10 may have an OD of about 2.6 French at the distal end 16 and an OD of about 2.8 French at the proximal end 14. In some cases, the catheter 10 may have an inner diameter (ID) of about 0.025 inches to 0.027 inches. In other cases, the catheter 10 may have an inner diameter of about 0.02 inches, 0.03 inches, or other appropriate inner diameters. These sizes may vary depending on the specific use.

[0035] In some cases, the distal tip 19 may be connected to or positioned around the distal end 16 of the elongated shaft 12. In some cases, the distal tip 19 may be a polymer distal tip and may be formed from an elastomer (e.g., Pebax®), a thermoplastic polymer, or other suitable polymer. The distal tip 19 may be formed from a material softer than the rest of the outer shaft of the catheter 10, for example, by using a polymer or elastomer with a Shore hardness of less than 40D. In some cases, the distal tip 19 may be formed from a polymer having a Shore hardness of about 35D. In some cases, the distal tip 19 may be a cauterizing tip configured to form an opening in the tissue wall. These are merely examples.

[0036] In some cases, as shown in the figure, the hub and strain relief assembly 18 may be connected to or positioned around the proximal end 14 of the elongated shaft 12. The hub and strain relief assembly 18 may include a main body 20, a pair of flanges 22 designed to improve grip, and a strain relief 24 intended to reduce bending. The hub and strain relief assembly 18 is a conventional design and can be mounted by prior art.

[0037] In some cases, catheter 10 may be considered an over-the-wire (OTW) microcatheter configured to overlap a guidewire and allow its entire length to pass along the guidewire. If catheter 10 is a rapid-exchange catheter, it will be understood that a lateral port may be provided to allow the guidewire to exit the catheter lumen distal to the proximal hub and strain relief assembly 18. These are merely examples.

[0038] Figure 2 shows a schematic partial view of the elongated shaft 112 of the illustrated catheter 100, showing the outer shaft 110, the inner shaft 120, and the distal tip 130, and Figure 3 shows a schematic enlarged view of the distal end region 121 of the inner shaft 120, shown in circle 3 of Figure 2. Catheter 100 can be considered an example of catheter 10 of Figure 1. The elongated shaft 112 may include an outer shaft 110 having a distal end region 111 and an inner surface 116 defining a lumen 115 extending inside it. The inner shaft 120 may extend at least partially into the lumen 115 of the outer shaft 110, and the inner shaft 120 may include a stent receiving portion 125 positioned along its distal end region 121. A stent 140 may be positioned along the stent receiving portion 125. The stent 140 may include a first end region, a second end region, and a central region located between the first and second end regions, as shown in Figures 6 to 10.

[0039] The catheter 100 may include a distal tip 130. The distal tip 130 may include a distal end 131 and a proximal end 132. The proximal end 132 of the distal tip 130 may be connected to the distal end 123 of the distal end region 121 of the internal shaft 120. In some cases, the distal tip 130 may include a plurality of hooks 135 positioned adjacent to the proximal edge 133 of the proximal end 132 of the distal tip 130. The plurality of hooks 135 may be configured to be positioned at equal intervals around the outer diameter of the proximal end 132 of the distal tip 130. In some cases, the plurality of hooks 135 may include a range of hooks from about 2 to 15. In some cases, the plurality of hooks 135 may include more than 15 hooks, or any desired number of hooks.

[0040] In some cases, one or more tethers 146 may be coupled to the first end region 141 of the stent 140. One or more tethers 146 may be configured to extend from the first end region 141 of the stent 140 to the distal tip 130 and may be configured to engage with a plurality of hooks 135 at the proximal end 132 of the distal tip 130, thereby coupling the stent 140 to the distal tip 130. In some cases, one or more tethers 146 may include specific tethers provided within the first end region 141 of the stent 140 so as to pass through, for example, a gap 166 in a radially expanding tubular framework 144. When one or more tethers 146 are passed through the first end region 141 of the stent 140, one or more tethers 146 may form a plurality of loops configured to engage with a plurality of hooks 135 on the distal tip 130. In some cases, the first end region 141 of the stent 140 may include a plurality of hooks 145, and one or more tethers 146 may be configured to form a plurality of loops and engage with the plurality of hooks 145 and the plurality of hooks 135. In some cases, when one or more tethers 146 include a particular tether, that tether may include a first end 151 and a second end (not explicitly shown in Figures 2-3). The second end may be configured to pass proximal through the lumen 115 of the outer shaft 110 along the outer surface of the inner shaft 120 to the proximal end of the catheter 100. In some cases, one or more tethers 146 may be formed from synthetic polymer materials such as polydioxanone, polyglycolic acid, polyglyconate, polylactic acid, nylon, or silk.

[0041] Figures 4 to 6 illustrate the illustrated method of deploying the stent 140 across two adjacent tissues, for example, a portion of the stomach 200 and a portion of the small intestine 210. Figure 7 shows a schematic side view of the stent 140 located between the stomach 200 and a portion of the small intestine 210, and Figure 8 shows a schematic cross-sectional view of the stent 140 located between the stomach 200 and a portion of the small intestine 210 along line 8-8 in Figure 7.

[0042] The method may include advancing the stent delivery system 50 to a target tissue site. As shown in Figure 4, the catheter 100 passes through the tissue walls of the stomach 200 and a portion of the small intestine 210. In the example shown, the distal tip 130 may be a cauterizing tip and is pressed against the tissue wall (e.g., a portion of the stomach 200 and small intestine 210) to cauterize the tissue wall. As the catheter 100 passes through the tissue wall, the outer shaft 110 comes into contact with the distal tip 130, thereby completely covering the stent 140, and the outer shaft 110 holds the stent 140 in the first pre-deployment configuration 101. The outer shaft 110 can be retracted proximal, thereby uncovering (i.e., exposing) at least a portion of the stent 140 positioned around the inner shaft 120. As the external shaft 110 is retracted proximal, the uncovered portion of the stent 140 expands radially outward from a first pre-deployment configuration 101 (Figure 4) to a second post-deployment configuration 102 (Figures 5-6). One or more tethers 146 may be configured to actuate proximal, as shown by arrow 117 in Figure 5, thereby pulling multiple hooks 135 at the proximal end 132 of the distal tip 130, which then contact the first end region 141 of the stent 140, expanding the first end region 141 of the stent 140 so that it includes the first flange structure 165 as shown in Figures 5-6. In some cases, one or more tethers 146 may be actuated by a user, and the user (e.g., a physician) may pull one or more tethers proximal. In some cases, one or more tethers 146 may be coupled to a ratchet mechanism, and the operation of the ratchet mechanism pulls one or more tethers 146 proximal, thereby expanding the first end region 141 of the stent 140.

[0043] In some cases, when one or more tethers 146 are activated proximal, the user can further retract the catheter 100 proximal. This allows the user to position the first flange structure 165 during the deployment of the stent 140. For example, the user can retract the catheter 100 proximal and activate one or more tethers 146 (e.g., pull or ratchet) to position the first flange structure 165 along the distal side of the first tissue structure (e.g., a portion of the small intestine 210). The continued activation of one or more tethers 146 applies tensile force to the distal tip 130, which is then pressed against the first end region 141 of the stent 140, expanding the first flange structure 165 to the desired size, thereby drawing the portion of the small intestine 210 towards the stomach 200.

[0044] Once the first flange structure 165 is in the desired position, the external shaft 110 can be fully retracted, and the second end region 142 of the stent 140 may expand to include the second flange structure 170. The second flange structure 170 may be positioned so that it abuts the distal side of the second tissue structure (e.g., the stomach 200), as shown in Figures 6-8. Once the stent 140 is positioned, the internal shaft 120, including the distal tip 130, can be retracted proximal. When the internal shaft 120 is retracted, one or more tethers 146 can be released, detached from the first end region 141 of the stent 140, and retracted proximal together with the internal shaft 120 and distal tip 130 for removal. In some cases, one or more tethers 146 may be cut at any position along the second end 152 of one or more tethers 146. As a result, one or more tethers 146 can detach from the first end region 141 of the stent 140 and be retracted proximally and removed together with the internal shaft 120 and distal tip 130.

[0045] The stent 140 may be a self-expanding stent 140 and may include a radially expanding tubular framework 144. The tubular framework 144 of the stent 140 has a radially expanding outer surface 148 and a radially expanding inner surface 149. The term “radially expanding tubular framework 144” may hereafter be referred to as “tubular framework 144”. In some cases, the stent 140 may include a height of 10 millimeters (mm) and an outer diameter (e.g., width) of 20 mm. In some cases, the height of the stent 140 may be 12 mm, 15 mm, 18 mm, in the range of 12 mm to 18 mm, or other appropriate height. In some cases, the outer diameter of the stent 140 may be 18 mm, 22 mm, 25 mm, in the range of 18 mm to 25 mm, or other appropriate diameter.

[0046] The tubular framework 144 may include a first end region 141, a second end region 142, and an intermediate region 143 located between the first end region 141 and the second end region 142. The tubular framework 144 may further include a lumen 147 extending from the first end region 141 to the second end region 142. In some cases, the first end region 141 may be considered a distal end region and the second end region 142 may be considered a proximal end region. In other cases, the first end region 141 may be considered a proximal end region and the second end region 142 may be considered a distal end region. The first end region 141 may extend from the first end 161 to the intermediate region 143, and the second end region 142 may extend from the second end 162 to the intermediate region 143. The intermediate region 143 may define the midpoint in the tubular framework 144. In that case, the first end region 141 and the second end region 142 may have the same length. Alternatively, the intermediate region 143 may be located at a position other than the midpoint, in which case the first end region 141 and the second end region 142 may have different lengths.

[0047] In some cases, the first end region 141 may include the first flange structure 165, and the second end region 142 may include the second flange structure 170. The intermediate region 143 may be located between the first flange structure 165 and the second flange structure 170. The first flange structure 165 and the second flange structure 170 can be considered as retaining members configured to help hold the stent 140 in place. Thus, the first flange structure 165 and the second flange structure 170 may include a width (e.g., outer diameter) sufficient to provide retaining strength. For example, the width of the first flange structure 165 and the second flange structure 170 may range from 20 mm to 70 mm. In some cases, the first flange structure 165 and the second flange structure 170 may include a width greater than the width of the first end 161, the second end 162, and the intermediate region 143 of the tubular framework 144. In some cases, the first flange structure 165 and the second flange structure 170 may have the same width. In some cases, the first flange structure 165 and the second flange structure 170 may have different widths. In some cases, the first flange structure 165 and the second flange structure 170 may include various shapes such as concave, convex, disc-shaped, cylindrical (e.g., having a longitudinal extension longer than shown), or other configurations, and the specific shapes and configurations are not limited by this disclosure. Although the first flange structure 165 is shown to be located near the first end region 141 and the second flange structure 170 is shown to be located near the second end region 142, it is also conceivable that the first flange structure 165 is located near the second end region 142 and the second flange structure 170 is located near the first end region 141. In some cases, the tubular framework 144 may be assumed to include only one flange structure (e.g., a first flange structure 165 or a second flange structure 170).

[0048] The stent 140 may be configured to be implanted between the patient's stomach 200 and jejunum 210 to form an anastomosis 215. In other embodiments, the stent 140 may be configured to be implanted, for example, in the urinary tract, biliary tract, tracheobronchial tract, esophagus, or renal tract. Since the stent 140 or a portion thereof may be intended to be permanently implanted in the lumen of the body, the stent 140 may be made of at least a portion of a biostable material. Examples of biostable metallic materials are not limited to stainless steel, tantalum, tungsten, niobium, platinum, nickel-chromium alloys, cobalt-chromium alloys such as Elgiloy® and Finox®, nitinol (e.g., 55% nickel, 45% titanium), cisplatin, and other titanium-based alloys (including nickel-titanium alloys), or other suitable metals, or combinations or alloys thereof. Suitable biostable polymer materials include, but are not limited to, polyamides, polyether block amides, polyethylene, polyethylene terephthalate, polypropylene, polyvinyl chloride, polyurethane, polytetrafluoroethylene, polysulfone, and copolymers, blends, mixtures, or combinations thereof.

[0049] The tubular framework 144 may include a number of interconnected struts 163, forming a mesh-like structure. The struts 163 may be configured to transition from a compressed state to an expanded state. The struts 163 may have diameters ranging from, for example, 0.0762 mm to 0.3556 mm. The tubular framework 144 may include a coating 164 applied to the struts 163 of the tubular framework 144, so that the entire stent 140 may be covered with the coating 164. The coating 164 may be formed from silicone and may be configured to prevent leakage of food material during anastomosis formation. In some cases, the coating 164 may be applied to the struts 163 in the intermediate region 143. In some cases, the coating 164 may be applied to the struts 163 in the first end region 141 and the intermediate region 143, or in some cases, to the struts 163 in the second end region 142 and the intermediate region 143. These are merely examples.

[0050] The stomach 200 normally allows food material (e.g., hygroscopic mucus, partially digested food material, fluids, etc.) to pass through the pylorus 260 into the duodenum 240. In some cases, treatment for patients with obesity, diabetes, or duodenal ulcers may involve bypassing the duodenum 240 or restricting the flow of material through the duodenum 240. If treatment requires a complete bypass of the duodenum 240, occlusion of the pylorus 260 (e.g., complete occlusion) may be indicated. An anastomosis 215 may be formed between the stomach 200 and the jejunum 210. This anastomosis may be known as a gastrojejunal anastomosis. Figure 7 shows an exemplary bypass procedure in which a flow limiting device 250 is placed in the pylorus 260, thereby restricting access to the flow of food material from the stomach 200 to the duodenum 240 (e.g., complete bypass). A luminal-opposing metal stent (LAMS), such as stent 140, is placed between the stomach 200 and the jejunum 210, thereby forming an anastomosis 215 that allows food material (fluid, liquid, hygroscopic, etc.) to pass from the stomach 200 to the jejunum 210, as shown in Figures 7-8. Although stent 140 is illustrated as being used to form an anastomosis 215 between the stomach 200 and the jejunum 210, stent 140 may also be used, in some cases, to treat intravascular stenosis, to maintain fluid openings or flows in the vascular, urinary, biliary, tracheobronchial, esophageal, or renal systems, or to place devices such as artificial valves or filters within the body's lumen. Although illustrated as a stent, stent 140 may be one of a number of devices that can be introduced endoscopically, subcutaneously, percutaneously, or surgically for placement within organs, tissues, or lumens such as the heart, arteries, veins, urethra, esophagus, trachea, bronchi, bile ducts, etc.

[0051] Figure 9 shows a schematic side view of the stent 140 positioned on the internal shaft 120 coupled to the distal tip 130, and Figure 10 shows a schematic perspective view of the stent 140 positioned on the internal shaft 120 with its first end region 141 in the deployed configuration 102. As previously described with reference to Figures 4 to 8, the external shaft 110 (not shown in Figures 9 and 10) can be retracted proximal, thereby uncovering (e.g., exposing) at least a portion of the stent 140 positioned around the internal shaft 120. When the external shaft 110 is retracted proximal, the uncovered portion of the stent 140 expands radially outward from the first pre-deployment configuration 101 (Figure 4) to the second deployed configuration 102 (Figures 9-10). One or more tethers 146 may be configured to actuate proximal, thereby pulling on multiple hooks 135 at the proximal end 132 of the distal tip 130, which then contact the first end region 141 of the stent 140, expanding the first end region 141 of the stent 140 so that it includes a first flange structure 165, and further expanding the second end region 142 of the stent 140 to include a second flange structure 170.

[0052] In some cases, when one or more tethers 146 are actuated proximal, a tensile force is applied to the distal tip 130, which then exerts a proximal force on the first end region 141 of the stent 140, causing the first flange structure 165 to expand radially outward to the desired size, thereby pulling the first tissue structure toward the second tissue structure. As previously stated, the first and second tissue structures may include portions of the stomach and small intestine, but it is thought that the first and second tissue structures may be any two adjacent non-adhesive structures, such as a hepatogastric anastomosis, a gallbladder drain, or the like.

[0053] In some cases, by activating (e.g., pulling) one or more tethers 146, the user may adjust the size of the first flange structure 165 as needed, allowing the distal tissue structure to be pulled toward the proximal tissue structure. During use, the distal tip 130 is actuated (e.g., pulled) in the proximal direction and tightened by the pulling or ratchet mechanism to a predetermined tension, thereby expanding the first flange structure 165 and making it rigid, as shown in Figure 10. This expands the outer diameter of the first flange structure 165, ensuring proper anchoring to the distal tissue structure.

[0054] The stent 140 and its components may be formed from metals, metal alloys, polymers (some examples of which are disclosed below), metal-polymer composites, ceramics, combinations thereof, and other suitable materials. Examples of suitable polymers include the following:That is, polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene (ETFE), fluoroethylene-propylene (FEP), polyoxymethylene (POM, e.g., DELRIN® from DuPont), polyether block esters, polyurethane (e.g., polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyether esters (e.g., ARNITEL® from DSM Engineering Plastics), ether-based or ester-based copolymers (e.g., butylene / poly(alkylene ether) phthalate and / or other polyester elastomers such as HYTREL® from DuPont), polyamides (e.g., DURETHAN® from Bayer or CRISTAMID® from Elf-Atchem), elastomeric polyamides, block polyamides / ethers, polyether block amides (PEBA, e.g., available as PEBAX®), ethylene-vinyl acetate copolymer (EVA), silicone, polyethylene (PE), MARLEX® high-density polyethylene, MAR LEX® low-density polyethylene, linear low-density polyethylene (e.g., REXELL®), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyether ether ketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), poly-p-phenylene terephthalamide (e.g., KEVLAR®), poly Examples include rufon, nylon, nylon-12 (e.g., GRILAMID® from EMS American Grillon), perfluoro(propyl vinyl ether) (PFA), ethylene-vinyl alcohol, polyolefins, polystyrene, epoxy, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS50A), polycarbonate, ionomer, biocompatible polymer, and other suitable materials, or mixtures, combinations, copolymers, polymer / metal composites thereof.In some embodiments, the sheath can be blended with a liquid crystal polymer (LCP). For example, the mixture may contain up to about 6% LCP.

[0055] In at least some embodiments, part or all of the stent 140 may be doped with, composed of, or include a radiopaque material. A radiopaque material is understood to be a material that can produce a relatively bright image on a fluoroscopy screen or other imaging technique during a medical procedure. This relatively bright image helps the user of the stent 140 to locate its position. Examples of radiopaque materials include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, and polymer materials containing radiopaque fillers. Furthermore, radiopaque marker bands and / or coils may be incorporated into the design of the stent 140 to achieve a similar effect.

[0056] In some embodiments, the stent 140 may be given a degree of suitability for magnetic resonance imaging (MRI). For example, the stent 140 or a part thereof may be formed from a material that does not substantially distort the image and does not produce significant artifacts (i.e., image defects). For example, certain ferromagnetic materials may not be suitable because they can produce artifacts in MRI images. The stent 140 or a part thereof may also be formed from a material that can be imaged by an MRI device. Examples of materials exhibiting these properties include tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS:R30003, ELGILOY®, PHYNOX®, etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R30035, MP35-N®, etc.), and nitinol.

[0057] It should be understood that this disclosure is illustrative in many respects. Details, particularly shape, dimensions, and process arrangement, can be modified without departing from the scope of this disclosure. This may include, to an appropriate extent, the use of features of one embodiment in other embodiments. The scope of this disclosure is, of course, defined by the language expressed in the appended claims.

Claims

1. A stent delivery system, An external shaft having a distal end region and an inner surface defining a lumen extending inward, An internal shaft having a stent receiving region that extends at least a portion within the lumen of the external shaft and is positioned along its distal end region, A distal tip is connected to the distal end of the distal end region of the internal shaft and has multiple hooks adjacent to the proximal end edge, A stent arranged along the stent receiving region, having a first end region, a second end region, and a central region located between the first end region and the second end region, One or more tethers coupled to the first end region of the stent, wherein the one or more tethers are configured to extend from the first end region to the distal tip and to engage with the plurality of hooks, thereby coupling the stent and the distal tip; Equipped with, One of the one or more tethers extends proximal within the lumen along the outer surface of the internal shaft, and the tether is configured to be activated by the user. The stent is configured to move between a first pre-position configuration and a second configuration, and is held in the first pre-position configuration when it is positioned within the lumen of the external shaft. Stent delivery system.

2. The stent delivery system according to claim 1, wherein the distal tip is a cauterizing tip.

3. The stent delivery system according to claim 1 or 2, wherein the first end region includes a first flange structure and the second end region includes a second flange structure.

4. The stent delivery system according to any one of claims 1 to 3, comprising a specific tether configured to be inserted into a first end region of the stent and to form a plurality of loops configured to engage with the plurality of hooks.

5. The stent delivery system according to claim 4, wherein the specific tether includes a first end and a second end, the second end being configured to extend proximal within the lumen along the outer surface of the internal shaft.

6. A stent delivery system according to any one of claims 1 to 5, wherein one of the one or more tethers is coupled to a ratchet mechanism, and the distal end region of the stent is expanded by the operation of the ratchet mechanism.

7. A stent delivery system according to any one of claims 1 to 6, wherein the first end region of the stent includes a plurality of hooks configured to engage with one or more tethers.

8. A stent delivery system according to any one of claims 1 to 7, wherein at least a portion of the stent is exposed by the proximal retraction of the external shaft, and the exposed portion of the stent expands radially outward as the external shaft is retracted proximal.

9. The stent delivery system according to claim 8, wherein when the external shaft is fully retracted proximal, the stent expands to a second deployment position, with the first end region positioned near a first tissue structure and the second end region positioned near a second tissue structure.

10. The stent delivery system according to claim 9, wherein when the stent is in a second deployed position, the internal shaft is retracted proximally, and one or more tethers detach from the first end region of the stent and are retracted proximally together with the internal shaft.

11. The stent delivery system according to claim 3, wherein the first flange structure has an outer diameter larger than the outer diameter of the second flange structure.

12. The stent delivery system according to claim 9 or 10, wherein when the stent expands to a second deployment position, the first tissue structure moves proximal to contact the second tissue structure.

13. The stent delivery system according to any one of claims 1 to 12, wherein the stent includes a covering.

14. The stent delivery system according to claim 13, wherein the coating is formed from silicone.

15. The stent delivery system according to any one of claims 1 to 14, wherein one or more tethers are formed from a synthetic polymer.

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