Gradually expanding anti-migration stent

Abstract

An exemplary medical device may include a stent having a radially expandable tubular framework. The radially expandable tubular framework includes a first end region, a second end region, an intermediate region positioned between the first end region and the second end region, and a lumen extending from the first end region to the second end region. The stent further includes a tubular structure positioned on the intermediate region, the tubular structure being formed from a bioabsorbable material and configured to maintain the intermediate region in a first compressed form. When the tubular structure is bioabsorbed, the intermediate region of the tubular framework radially expands into a second expanded form. One of the first end region or the second end region includes a first flange structure.

Description

Technical Field

[0001] The present disclosure generally relates to the field of implantable medical devices for regulating access through medical device passages, as well as related systems and methods. More specifically, the present disclosure relates to devices, systems, and methods for controlling and / or altering a passageway using a flow regulation device such as a lumen juxtaposition device.

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, pyloric obstruction (e.g., complete obstruction) may be indicated, and an anastomosis may be formed, for example, between the stomach and the jejunum. A lumen juxtaposition device may be disposed between the stomach and the jejunum to permit passage of substances (fluids, liquids, chyme, etc.) from the stomach into the jejunum. One problem presented by such devices is preventing distal migration of the device into the small intestine or proximal migration of the device into the stomach. Accordingly, there is a continuing need to provide alternative medical devices and alternative methods for manufacturing and using medical devices.

Summary of the Invention

[0003] The present disclosure provides alternatives for the design, materials, manufacturing methods, and use of medical devices. An exemplary medical device may include a stent having a radially expandable tubular framework. The radially expandable tubular framework may include a radially outer surface, a radially inner surface, a first end region, a second end region, an intermediate region positioned between the first end region and the second end region, and a lumen extending from the first end region to the second end region. The stent may further include a tubular structure positioned on the intermediate region, and the tubular structure may be configured to maintain the intermediate region in a first compressed form. One of the first end region or the second end region may include a first flange structure.

[0004] Instead of or in addition to any of the above embodiments, the tubular structure may be formed from a bioabsorbable material. Instead of or in addition to any of the above embodiments, when the tubular structure is bioabsorbed, the intermediate region of the tubular framework may expand radially into a second expanded configuration.

[0005] Instead of or in addition to any of the above embodiments, the expansion of the intermediate region of the tubular framework may be gradual over a period of time due to the bioabsorption of the tubular structure.

[0006] Instead of or in addition to any of the above embodiments, when the intermediate region is in the second expanded configuration, the intermediate region may be configured to engage the tissue surface and thereby prevent movement of the stent by exerting a radial force.

[0007] Instead of or in addition to any of the above embodiments, the intermediate region of the tubular framework may include a first inner diameter when in the first compressed configuration and a second inner diameter when in the second expanded configuration, and the second inner diameter is greater than the first inner diameter.

[0008] Instead of or in addition to any of the above embodiments, the second inner diameter may be 25% greater than the first inner diameter. Instead of or in addition to any of the above embodiments, the second inner diameter may be 10% to 25% greater than the first inner diameter.

[0009] Instead of or in addition to any of the above embodiments, the radially expanding tubular framework may include a coating applied on the tubular framework. Instead of or in addition to any of the above embodiments, the other of the first end region or the second end region may include a second flange structure.

[0010] An exemplary stent may include a radially expandable tubular framework having a radially outer surface, a radially inner surface, a first end region, a second end region, an intermediate region positioned between the first end region and the second end region, and a lumen extending from the first end region to the second end region. The stent may further include a tubular structure formed from a bioabsorbable material positioned over the intermediate region, the tubular structure being configured to maintain the intermediate region in a first compressed configuration, and when the tubular structure is bioabsorbed, the intermediate region of the tubular framework radially expands to a second expanded configuration. The radially expandable tubular framework may include a coating applied over the tubular framework.

[0011] Instead of or in addition to any of the above embodiments, when the intermediate region is in the second expanded configuration, the intermediate region may be configured to engage a tissue surface and thereby prevent movement of the stent by exerting a radial force.

[0012] Instead of or in addition to any of the above embodiments, the intermediate region of the tubular framework may include a first inner diameter when in the first compressed configuration and a second inner diameter when in the second expanded configuration, the second inner diameter being greater than the first inner diameter.

[0013] Instead of or in addition to any of the above embodiments, the second inner diameter may be 25% greater than the first inner diameter. Instead of or in addition to any of the above embodiments, the second inner diameter may be 10% to 25% greater than the first inner diameter.

[0014] Instead of or in addition to 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.

[0015] The exemplary stent may include a radially expandable tubular framework having a first end region, a second end region, and an intermediate region positioned between the first end region and the second end region. The stent may further include a tubular structure formed from a bioabsorbable material positioned on the intermediate region, the tubular structure being configured to maintain the intermediate region in a first compressed configuration, and when the tubular structure is bioabsorbed, the intermediate region of the tubular framework radially expands to a second expanded configuration. The expansion of the intermediate region of the tubular framework may be gradual over a period of time due to the bioabsorption of the tubular structure, and the intermediate region of the tubular framework may include a first inner diameter when in the first compressed configuration and a second inner diameter when in the second expanded configuration, and the second inner diameter may be larger than the first inner diameter.

[0016] Instead of or in addition to any of the above embodiments, when the intermediate region is in the second expanded configuration, the intermediate region may be configured to engage the tissue surface and thereby prevent movement of the stent by exerting a radial force.

[0017] Instead of or in addition to any of the above embodiments, the second inner diameter may be 25% larger than the first inner diameter. Instead of or in addition to any of the above embodiments, the second inner diameter may be 10% to 25% larger than the first inner diameter.

[0018] The above summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The following drawings and detailed description illustrate these embodiments more specifically.

[0019] 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

[0020]

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[0021] Although this disclosure can accept various modified forms and alternative forms, their details are shown in the drawings as examples and will be described in detail. However, it should be understood that the intention is not to limit the invention to the specific embodiments described. On the contrary, the intention is to include all modified forms, equivalents, and alternative forms that fall within the spirit of this disclosure.

[0022] For the terms defined below, these definitions shall apply unless different definitions are given in the claims or elsewhere in this specification. All numerical values are assumed to be modified by the term "about" in this specification, whether or not explicitly indicated. The term "about" generally refers to a range of numbers that a person skilled in the art would consider equivalent to the recited value (e.g., having the same function or result). In many cases, the term "about" may include numbers rounded to the nearest significant digit.

[0023] The recitation of a numerical range by endpoints includes all numbers within that range (e.g., 1 - 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly indicates otherwise. As used in this specification and the appended claims, the term "or" is generally used in the sense of "and / or" unless the context clearly indicates otherwise.

[0024] Note that references to "Embodiments", "Some embodiments", "Other embodiments", etc. in this specification are intended to 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 the specific features, structures, and / or characteristics. In addition, when 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 can also be used in relation to other embodiments, whether or not explicitly described, unless otherwise specifically stated.

[0025] According to various principles of the present disclosure, an implantable device can be used to control or adjust the size of a passage therethrough by extending across an anatomical structure. For example, the implantable device may extend across a body passage or lumen (such terms are used synonymously herein without intention of limitation). The body passage or lumen 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 by traversing juxtaposed tissue walls (such as for forming an anastomosis), and the like. The device may have a passage or lumen (such terms are used synonymously herein without intention of limitation) through which the device passes for occluding or blocking or narrowing or closing or constricting or regulating or controlling (such terms and their conjugations are used synonymously herein without intention of limitation) the body passage through which the device is positioned. The device may be regarded as an occlusion device or a lumen juxtaposition device or an anastomosis device or a flow regulation device or a flow control device and may be so referred to, and such terms and various other alternatives thereof may be used synonymously herein without intention of limitation.

[0026] It should be understood that the devices, systems, and methods disclosed herein may be used in endoscopy, laparoscopy, and / or open surgery. Preferably, a medical professional may be able to deliver and / or remove the device endoscopically. Advantageously, the devices and systems disclosed herein may be used in minimally invasive procedures such as natural orifice transluminal endoscopic surgery (NOTES).

[0027] The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered the same. The drawings are not necessarily to scale, illustrate exemplary embodiments, and are not intended to limit the scope of the invention.

[0028] Figure 1 shows a perspective view of an exemplary stent 10 positioned between the stomach 20 and the jejunum 30 (a part of the small intestine), and Figure 2 shows a cross-sectional view of the stent 10 positioned between the stomach 20 and the jejunum 30 along line 2-2 of Figure 1. The stent 10 may be a self-expanding stent 10 and may include a radially expandable tubular framework 13 having a radially outer surface 11 and a radially inner surface 12. The radially expandable tubular framework 13 may include a first end region 16, a second end region 17, and an intermediate region 18 positioned between the first end region 16 and the second end region 17. The radially expandable tubular framework 13 may further include a lumen 14 extending from the first end region 16 to the second end region 17. The stomach 20 typically passes food substances (e.g., gruel, partially digested food substances, fluids, etc.) through the pylorus 60 into the duodenum 40. In some cases, the treatment of patients experiencing obesity, diabetes, or duodenal ulcers may include bypassing the duodenum 40 or restricting the flow of substances through the duodenum 40. If the treatment requires a complete bypass of the duodenum 40, occlusion of the pylorus 60 (e.g., complete occlusion) may be shown, and an anastomosis 15 may be formed between the stomach 20 and the jejunum 30, which may be known as a gastrojejunostomy. Figure 1 shows an exemplary bypass procedure in which a flow restriction device 50 is positioned within the pylorus 60, thereby restricting access of food substances from the stomach 20 to the duodenum 40 (e.g., complete bypass). As shown in Figures 1 and 2, a lumen apposing metal stent (LAMS) such as the stent 10 may be placed between the stomach 20 and the jejunum 30, thereby forming an anastomosis 15 so that food substances (fluids, liquids, gruel, etc.) can pass from the stomach 20 into the jejunum 30.Although the stent 10 is shown to be usable when forming an anastomosis 15 between the stomach 20 and the jejunum 30, the stent 10 may be used to treat stenosis within a blood vessel, or may be used to maintain a fluid opening or passage within a blood vessel, urinary tract, biliary tract, tracheobronchial tree, esophagus, or renal tract, or in some cases may be assumed to be used to position a device such as an artificial valve or filter within a body lumen. Although shown as a stent, the stent 10 may be any of a number of devices that can be introduced endoscopically, subcutaneously, percutaneously, or surgically so as to be positioned within an organ, tissue, or lumen such as the heart, artery, vein, urethra, esophagus, trachea, bronchus, or bile duct.

[0029] FIG. 3 shows a side view of an exemplary stent 100. The stent 100 can be an example of the stent 10 of FIGS. 1-2. The stent 100 may include a radially expanding tubular framework 105 having a radially outer surface 101 and a radially inner surface (not shown in FIG. 3). The radially inner surface can be regarded as an example of the radially inner surface 12 as shown in FIG. 2. The term "radially expanding tubular framework 105" may hereinafter be referred to as "tubular framework 105". The stent 100 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 100 may be 12 mm, 15 mm, 18 mm, 12 mm to 18 mm, or any other suitable height. In some cases, the outer diameter of the stent 100 may be 18 mm, 22 mm, 25 mm, 18 mm to 25 mm, or any other suitable diameter. The tubular framework 105 may include a first end region 110, a second end region 120, and an intermediate region 130 positioned between the first end region 110 and the second end region 120. The tubular framework 105 may further include a lumen 140 extending from the first end region 110 to the second end region 120. The lumen 140 can be regarded as an example of the lumen 14 as shown in FIG. 2. In some cases, the first end region 110 may be regarded as the distal end region, or the second end region 120 may be regarded as the proximal end region. In an alternative case, the first end region 110 may be regarded as the proximal end region, or the second end region 120 may be regarded as the distal end region. The first end region 110 may include a first end 111, and the second end region 120 may include a second end 121. The first end region 110 may extend from the first end 111 to the intermediate region 130, or the second end region 120 may extend from the second end 121 to the intermediate region 130. The intermediate region 130 may define a midpoint within the tubular framework 105 such that the first end region 110 and the second end region 120 can have the same length. Alternatively, the intermediate region 130 may be located at a position other than the midpoint such that the first and second end regions 110, 120 have different lengths.

[0030] In some cases, the first end region 110 may include a first flange structure 115, and the second end region 120 may include a second flange structure 125. The intermediate region 130 may be positioned between the first flange structure 115 and the second flange structure 125. The first flange structure 115 and the second flange structure 125 may be regarded as holding members configured to assist in maintaining the stent 100 in a fixed position. Accordingly, the first and second flange structures 115, 125 may include a width (e.g., outer diameter) sufficient to provide holding strength. For example, the width of the first and second flange structures 115, 125 may be in the range of 20 to 70 mm. In some cases, the first and second flange structures 115, 125 may include a width greater than the width of the first end 111, the second end 121, and the intermediate region 130 of the tubular framework 105. In some cases, the first and second flange structures 115, 125 may include the same width. In some cases, the first and second flange structures 115, 125 may include different widths. In some cases, the first and second flanges 115, 125 may include any of various shapes such as concave, convex, disc-shaped, cylindrical (e.g., having a longer longitudinal range than shown), or other configurations, and the specific shapes and configurations are not limited by the present disclosure. Although it is shown that the first flange structure 115 is positioned near the first end region 110 and the second flange structure 125 is positioned near the second end region 120, it is also conceivable that the first flange structure 115 is positioned near the second end region 120 and the second flange structure 125 is positioned near the first end region 110. In some cases, it is conceivable that the tubular framework 105 includes only one flange structure (e.g., the first flange structure 115 or the second flange structure 125).

[0031] The stent 100 may be configured to be implanted between a patient's stomach and jejunum to form an anastomosis. In other embodiments, the stent 100 may be configured to be implanted, for example, in the urinary tract, biliary tract, tracheobronchial tree, esophagus, or renal tract. Since the stent 100 or a portion thereof may be intended to be permanently implanted within a body lumen, the stent 100 may be made, at least in part, from a biostable material. Examples of biostable metallic materials include stainless steel, tantalum, tungsten, niobium, platinum, nickel-chromium alloys, cobalt-chromium alloys such as Elgiloy® and Phynox®, 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, but are not limited thereto. Some suitable biostable polymeric materials include polyamide, polyether block amide, polyethylene, polyethylene terephthalate, polypropylene, polyvinyl chloride, polyurethane, polytetrafluoroethylene, polysulfone, and copolymers, blends, mixtures, or combinations thereof, but are not necessarily limited thereto.

[0032] The tubular framework 105 may include several interconnected struts 106 so as to form a mesh-like structure of the tubular framework 105. The struts 106 may be configured to transition from a compressed state to an expanded state. The struts 106 may include, for example, a diameter of 0.0762 mm to 0.3556 mm. The tubular framework 105 may include a coating 107 applied on the struts 106 of the tubular framework 105, and thus, the entire stent 100 may be covered with the coating 107. The coating 107 may be formed from silicone and may be configured to prevent leakage of food substances during anastomosis formation. In some cases, the coating 107 may be applied on the struts 106 in the intermediate region 130. In some cases, the coating 107 may be applied on the struts 106 within the first end region 110 and the intermediate region 130, and in some cases, the coating 107 may be applied on the struts 106 within the second end region 120 and the intermediate region 130. These are merely examples.

[0033] In some cases, the stent 100 may include a tubular structure 150 positioned on the intermediate region 130 as shown in FIGS. 4 and 5. FIG. 4 shows a perspective view of an exemplary tubular structure 150, and FIG. 5 shows a top view of the exemplary tubular structure 150. The tubular structure 150 may be formed from a bioabsorbable material and may be configured to maintain the intermediate region 130 in a first compressed form as shown in FIGS. 6, 8, 9, 12, and 13. Examples of suitable bioabsorbable materials may include polymers such as polygycamin, poly-L-lactide (PLLA), polyglycolide (PGA), polylactide (PLA), poly-D-lactide (PDLA), polycaprolactone, polydioxanone, polygluconate, poly(lactic acid)-poly(ethylene oxide) copolymer, modified cellulose, collagen, poly(hydroxybutyrate), polyanhydride, polyphosphate ester, poly(amino acid), and combinations thereof.

[0034] The bioabsorbable material of the tubular structure 150 can be absorbed by the patient's body via blood flow, other fluids, and / or other natural compositions over a period of time after the stent 100 is implanted in the body. The tubular structure 150 may include a thickness within the range of 0.102 mm to 0.203 mm. In such a case, when the stent 100 is implanted between the gastric wall of the stomach and the jejunum, the bioabsorbable material of the tubular structure 150 may be completely absorbable within 6 weeks from insertion. In some cases, the tubular structure 150 may have a thickness of 0.05 mm, 0.075 mm, 0.25 mm, 0.30 mm, or any other suitable thickness. In some cases, the bioabsorbable material of the tubular structure 150 may be completely absorbable within 2 weeks, within 4 weeks, within 8 weeks, or within any other suitable time frame. In some cases, the time frame for bioabsorption of the tubular structure 150 can be adjusted by changing the thickness of the tubular structure 150 and / or by varying the composition of the tubular structure 150 (e.g., by including various additives). As described above, the tubular structure 150 may be configured to maintain the intermediate region 130 of the tubular framework 105 in a first compressed form. The intermediate region 130 of the tubular framework 105 may be biased to a second expanded form. Thus, when the tubular structure 150 is bioabsorbed, the intermediate region 130 of the tubular framework 105 can radially expand to the second expanded form as shown in FIGS. 7, 10, 11, 14, and 15. Thus, the expansion of the intermediate region 130 of the tubular framework 105 can be gradual over a period of time due to the bioabsorption of the tubular structure 150.

[0035] FIG. 6 shows an exemplary stent 200 that includes a tubular structure 250 positioned between a gastric wall 260 (e.g., the stomach) and a portion of the small intestine 270 (e.g., the jejunum). The stent 200 may include a radially expandable tubular framework 205 having a radially outer surface 201 and a radially inner surface (not shown in FIG. 6). The radially inner surface may be considered an example of the radially inner surface 12 as shown in FIG. 2. The term "radially expandable tubular framework 205" may hereinafter be referred to as the "tubular framework 205". The stent 200 may include a height of 10 mm and an outer diameter (e.g., width) of 20 mm. In some cases, the height of the stent 200 may be 12 mm, 15 mm, 18 mm, or any other suitable height. In some cases, the outer diameter of the stent 200 may be 18 mm, 22 mm, 25 mm, or any other suitable diameter. The tubular framework 205 may include a first end region 210, a second end region 220, and an intermediate region 230 positioned between the first end region 210 and the second end region 220. The tubular framework 205 may further include a lumen 240 extending from the first end region 210 to the second end region 220. The lumen 240 may be considered an example of the lumen 14 as shown in FIG. 2. In some cases, the first end region 210 may be considered the distal end region, or the second end region 220 may be considered the proximal end region. In some cases, the first end region 210 may be considered the proximal end region, or the second end region 220 may be considered the distal end region. The first end region 210 may include a first end 211, and the second end region 220 may include a second end 221. The first end region 210 may extend from the first end 211 to the intermediate region 230, or the second end region 220 may extend from the second end 221 to the intermediate region 230. The intermediate region 230 may include a midpoint within the tubular framework 205 such that the first end region 210 and the second end region 220 may have the same length. Alternatively, the intermediate region 230 may be positioned at a location other than the midpoint such that the first and second end regions 210, 220 have different lengths.

[0036] In some cases, the first end region 210 may include a first flange structure 215, and the second end region 220 may include a second flange structure 225. The intermediate region 230 may be positioned between the first flange structure 215 and the second flange structure 225. The first flange structure 215 and the second flange structure 225 may be regarded as holding members configured to assist in maintaining the stent 200 in a fixed position. Accordingly, the first and second flange structures 215, 225 may include a width (e.g., outer diameter) sufficient to provide holding strength. For example, the width of the first and second flange structures 215, 225 may be in the range of 20 to 70 mm. In some cases, the first and second flange structures 215, 225 may include a width greater than the widths of the first end 211, the second end 221, and the intermediate region 230 of the tubular framework 205. In some cases, the first and second flange structures 215, 225 may include the same width. In some cases, the first and second flange structures 215, 225 may include different widths. In some cases, the first and second flanges 215, 225 may include any of various shapes such as concave, convex, disk-shaped, cylindrical (e.g., having a longer longitudinal range than shown), or other configurations, and the specific shapes and configurations are not limited by the present disclosure. Although it is shown that the first flange structure 215 is positioned near the first end region 210 and the second flange structure 225 is positioned near the second end region 220, it is also conceivable that the first flange structure 215 is positioned near the second end region 220 and the second flange structure 225 is positioned near the first end region 210. In some cases, it is conceivable that the tubular framework 205 includes only one flange structure (e.g., the first flange structure 215 or the second flange structure 225).

[0037] The tubular framework 205 may include several interconnected struts 206 so as to form a mesh-like structure of the tubular framework 205. The struts 206 may be configured to transition from a compressed state to an expanded state. The struts 206 may include, for example, a diameter of 0.0762 mm to 0.3556 mm. The tubular framework 205 may include a coating 207 applied on the struts 206 of the tubular framework 205, and thus may cover the entire stent 200 with the coating 207. The coating 207 may be formed from silicone and may be configured to prevent leakage of food substances during anastomosis formation. In some cases, the coating 207 may be applied on the struts 206 in the intermediate region 230. In some cases, the coating 207 may be applied on the struts 206 within the first end region 210 and the intermediate region 230, and in some cases, the coating 207 may be applied on the struts 206 within the second end region 220 and the intermediate region 230. These are merely examples.

[0038] In some cases, the stent 200 may include a tubular structure 250 positioned on the intermediate region 230, as shown in FIG. 6. In such a case, the intermediate region 230 of the stent 200 and the tubular structure 250 may be positioned between the stomach and the jejunum and may be configured to engage the walls of the lumens formed within the stomach and the jejunum. The tubular structure 250 may be formed from a bioabsorbable material and may be configured to maintain the intermediate region 230 in a first compressed form 290, as shown in FIG. 6. Examples of suitable bioabsorbable materials may include polymers such as polygycamin, poly-L-lactide (PLLA), polyglycolide (PGA), polylactide (PLA), poly-D-lactide (PDLA), polycaprolactone, polydioxanone, polygluconate, poly(lactic acid)-poly(ethylene oxide) copolymer, modified cellulose, collagen, poly(hydroxybutyrate), polyanhydrides, polyphosphate esters, poly(amino acids), and combinations thereof.

[0039] The bioabsorbable material of the tubular structure 250 can be absorbed by the patient's body through blood flow, other fluids, and / or other natural compositions over a period of time after the stent 200 is implanted in the body. The tubular structure 250 may include a thickness in the range of 0.102 mm to 0.203 mm. In such a case, when the stent 200 is implanted between the gastric wall of the stomach and the jejunum, the bioabsorbable material of the tubular structure 250 can be completely absorbed within 6 weeks from insertion. In some cases, the tubular structure 250 may have a thickness of 0.05 mm, 0.075 mm, 0.25 mm, 0.30 mm, or any other suitable thickness. In some cases, the bioabsorbable material of the tubular structure 250 may be completely absorbable within 2 weeks, 4 weeks, 8 weeks, 10 weeks, 12 weeks, or any other suitable time frame. In some cases, the time frame for bioabsorption of the tubular structure 250 can be adjusted by changing the thickness of the tubular structure 250 and various additives. As described above, the tubular structure 250 may be configured to maintain the intermediate region 230 of the tubular framework 205 in the first compressed form 290. The intermediate region 230 may include an inner diameter of about 15 millimeters (mm) when in the first compressed form 290. In some cases, the intermediate region 230 may include an inner diameter of about 10 mm, 12 mm, 18 mm, or any other suitable diameter.

[0040] As shown in FIG. 7, when the tubular structure 250 is bioabsorbed, the intermediate region 230 of the tubular framework 205 can expand radially into a second expanded configuration 295. The expansion of the intermediate region 230 of the tubular framework 205 is gradual over a period of time due to the bioabsorption of the tubular structure 250, which may enable the formation of the anastomosis 280. The anastomosis 280 is formed around the intermediate region 230 when the intermediate region 230 is in the first compressed configuration. Thus, when the tubular structure 250 disintegrates and the intermediate region 230 is in the second expanded configuration 295, the intermediate region 230 may be configured to engage the tissue surface (e.g., the anastomosis) and thereby prevent movement of the stent 200 by exerting a radial force as indicated by the arrows in FIG. 7. In some cases, an increasing axial force on the anastomosis 280 may promote faster patency and thereby reduce movement of the stent 200.

[0041] The intermediate region 230 of the tubular framework 205 may expand 25% when the bioabsorbable tubular structure 250 is absorbed in the body. In some cases, the intermediate region 230 of the tubular framework 205 may expand by 10% - 25%, or any other suitable percentage. Thus, when the intermediate region 230 is in the second expanded configuration, the intermediate region 230 may include an inner diameter of 20 mm. In some cases, the intermediate region 230 may include an inner diameter of 12.5 mm, 15 mm, 22.5 mm, 12 mm - 23 mm, or any other suitable diameter.

[0042] Figures 8 and 9 show an exemplary stent 300 in a first compression configuration 360, and the stent 300 includes a tubular structure 350. The stent 300 may be an example of the stent 200 shown in FIGS. 6 and 7. The stent 300 may include a radially expanding tubular framework 305 having a radially outer surface 301 and a radially inner surface 302. The term "radially expanding tubular framework 305" may hereinafter be referred to as "tubular framework 305". The stent 300 may include a height of 10 mm and an outer diameter (e.g., width) of 20 mm. In some cases, the height of the stent 300 may be 12 mm, 15 mm, 18 mm, 12 mm to 18 mm, or any other suitable height. In some cases, the outer diameter of the stent 300 may be 18 mm, 22 mm, 25 mm, 18 mm to 25 mm, or any other suitable diameter. The tubular framework 305 may include a first end region 310, a second end region 320, and an intermediate region 330 positioned between the first end region 310 and the second end region 320. The tubular framework 305 may further include a lumen 340 extending from the first end region 310 to the second end region 320. In some cases, the first end region 310 may be considered a distal end region, or the second end region 320 may be considered a proximal end region. In some cases, the first end region 310 may be considered a proximal end region, or the second end region 320 may be considered a distal end region. The first end region 310 may include a first end 311, and the second end region 320 may include a second end 321. The first end region 310 may extend from the first end 311 to the intermediate region 330, or the second end region 320 may extend from the second end 321 to the intermediate region 330. The intermediate region 330 may define an intermediate point within the tubular framework 305 such that the first end region 310 and the second end region 320 may have the same length. Alternatively, the intermediate region 330 may be disposed at a position other than the intermediate point such that the first and second end regions 310, 320 have different lengths.

[0043] In some cases, the first end region 310 may include a first flange structure 315, and the second end region 320 may include a second flange structure 325. The intermediate region 330 may be positioned between the first flange structure 315 and the second flange structure 325. The first flange structure 315 and the second flange structure 325 may be regarded as holding members configured to assist in maintaining the stent 300 in a fixed position. Accordingly, the first and second flange structures 315, 325 may include a width (e.g., outer diameter) sufficient to provide holding strength. For example, the width of the first and second flange structures 315, 325 may be in the range of 20 to 70 mm. In some cases, the first and second flange structures 315, 325 may include a width greater than the width of the first end 311, the second end 321, and the intermediate region 330 of the tubular framework 305. In some cases, the first and second flange structures 315, 325 may include the same width. In some cases, the first and second flange structures 315, 325 may include different widths. In some cases, the first and second flanges 315, 325 may include any of various shapes such as concave, convex, disk-shaped, cylindrical (e.g., having a longer longitudinal range than shown), or other configurations, and the specific shapes and configurations are not limited by the present disclosure. Although it is shown that the first flange structure 315 is positioned near the first end region 310 and the second flange structure 325 is positioned near the second end region 320, it is also conceivable that the first flange structure 315 is positioned near the second end region 320 and the second flange structure 325 is positioned near the first end region 310. In some cases, it is conceivable that the tubular framework 305 includes only one flange structure (e.g., the first flange structure 315 or the second flange structure 325).

[0044] The tubular framework 305 may include several interconnected struts 306 so as to form a mesh-like structure of the tubular framework 305. The struts 306 may be configured to transition from a compressed state to an expanded state. The struts 306 may include, for example, a diameter of 0.0762 mm to 0.3556 mm. The tubular framework 305 may include a coating 307 applied on the struts 306 of the tubular framework 305, and thus, the entire stent 300 may be covered with the coating 307. The coating 307 may be formed from silicone and may be configured to prevent leakage of food substances during anastomosis formation. In some cases, the coating 307 may be applied on the struts 306 in the intermediate region 330. In some cases, the coating 307 may be applied on the struts 306 within the first end region 310 and the intermediate region 330, and in some cases, the coating 307 may be applied on the struts 306 within the second end region 320 and the intermediate region 330. These are merely examples.

[0045] As described above, the stent 300 may include a tubular structure 350 positioned over the intermediate region 330, as shown in FIG. 9. The tubular structure 350 may be formed from a bioabsorbable material and may be configured to maintain the intermediate region 330 in a first compressed form 360. When the intermediate region 330 is in the first compressed form 360, the intermediate region 330 of the tubular framework 305 may include a first inner diameter D1 of about 15 mm. In some cases, the intermediate region 330 may include a first inner diameter D1 of about 10 mm, 12 mm, 18 mm, 10 mm to 18 mm, or any other suitable diameter.

[0046] The bioabsorbable material of the tubular structure 350 can be absorbed by the patient's body via blood flow, other fluids, and / or other natural compositions over a period of time after the stent 300 is implanted into the body. The tubular structure 350 may include a thickness within the range of 0.102 mm to 0.203 mm. In such a case, when the stent 300 is implanted between the gastric wall of the stomach and the jejunum, the bioabsorbable material of the tubular structure 350 may be completely absorbable within 6 weeks from insertion. In some cases, the bioabsorbable material of the tubular structure 350 may be completely absorbable within 2 weeks, within 4 weeks, within 8 weeks, or within any other suitable time frame. In some cases, the time frame for bioabsorption of the tubular structure 350 can be adjusted by changing the thickness of the tubular structure 350 and various additives.

[0047] As shown in FIGS. 10-11, when the tubular structure 350 is bioabsorbed, the intermediate region 330 of the tubular framework 305 can expand radially into a second expanded form 370. The expansion of the intermediate region 330 of the tubular framework 305 can be gradual over a period of time due to the bioabsorption of the tubular structure 350, which may enable the formation of an anastomosis. The anastomosis is formed around the intermediate region 330 when the intermediate region 330 is in the first compressed form 360. Thus, when the tubular structure 350 collapses and the intermediate region 330 is in the second expanded form 370, the intermediate region 330 may be configured to engage the tissue surface (e.g., the anastomosis) and thereby prevent movement of the stent 300 by exerting a radial force. In some cases, an axially increasing force on the anastomosis can promote faster patency and thereby reduce movement of the stent 300.

[0048] Figures 10 and 11 show the exemplary stents of FIGS. 8 and 9 in a second expanded configuration 370. When in the second expanded configuration 370, the intermediate region 330 of the tubular framework 305 can expand by 25% when the bioabsorbable tubular structure 350 is absorbed in the body. In some cases, the intermediate region 330 of the tubular framework 305 may expand by 10% - 25%, or any other suitable percentage. In other words, the intermediate region 330 of the tubular framework 305 may include a first inner diameter D1 when in the first compressed configuration 360 and a second inner diameter D2 when in the second expanded configuration 370. Thus, when the intermediate region 330 is in the second expanded configuration 370, the intermediate region 330 may include a second inner diameter D2 of 20 mm. In some cases, the intermediate region 330 may include a second inner diameter D2 of 12.5 mm, 15 mm, 22.5 mm, 12 mm - 23 mm, or any other suitable diameter. In some cases, the second inner diameter D2 may be 25% larger than the first inner diameter D1. In some cases, the second inner diameter D2 may be 10% - 25% larger than the first inner diameter D1. In some cases, the second inner diameter D2 may be 30% larger than the first inner diameter D1.

[0049] Figures 12 and 13 show an exemplary stent 400 in a first compression configuration 460. The stent 400 includes a tubular structure 450. The stent 400 may be an example of the stent 200 shown in FIGS. 6 and 7. The stent 400 may include a radially expanding tubular framework 405 having a radially outer surface 401 and a radially inner surface 402. The term "radially expanding tubular framework 405" may hereinafter be referred to as the "tubular framework 405". The stent 400 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 400 may be 12 mm, 15 mm, 18 mm, 12 mm to 18 mm, or any other suitable height. In some cases, the outer diameter of the stent 400 may be 18 mm, 22 mm, 25 mm, 18 mm to 25 mm, or any other suitable diameter. The tubular framework 405 may include a first end region 410, a second end region 420, and an intermediate region 430 positioned between the first end region 410 and the second end region 420. The tubular framework 405 may further include a lumen 440 extending from the first end region 410 to the second end region 420. In some cases, the first end region 410 may be considered the distal end region, or the second end region 420 may be considered the proximal end region. In some cases, the first end region 410 may be considered the proximal end region, or the second end region 420 may be considered the distal end region. The first end region 410 may include a first end 411, and the second end region 420 may include a second end 421. The first end region 410 may extend from the first end 411 to the intermediate region 430, or the second end region 420 may extend from the second end 421 to the intermediate region 430. The intermediate region 430 may define an intermediate point within the tubular framework 405 such that the first end region 410 and the second end region 420 may have the same length. Alternatively, the intermediate region 430 may be disposed at a position other than the intermediate point such that the first and second end regions 410, 420 have different lengths.In some cases, the first end region 410 and the second end region 420 may each include an outer diameter larger than the outer diameter of the intermediate region 430. As shown in FIGS. 12 and 14, the stent 400 may include a "bow tie" shape. The diameter of the first end region 410 may gradually increase from the intermediate region 430 to the first end 411, or the diameter of the second end region 420 may gradually increase from the intermediate region 430 to the second end 421.

[0050] The tubular framework 405 may include several interconnected struts 406 so as to form a mesh-like structure of the tubular framework 405. The struts 406 may be configured to transition from a compressed state to an expanded state. The struts 406 may include, for example, a diameter of 0.0762 mm to 0.3556 mm. The tubular framework 405 may include a coating 407 applied on the struts 406 of the tubular framework 405, and thus, the entire stent 400 may be covered with the coating 407. The coating 407 may be formed from silicone and may be configured to prevent leakage of food substances during anastomosis formation. In some cases, the coating 407 may be applied on the struts 406 in the intermediate region 430. In some cases, the coating 407 may be applied on the struts 406 within the first end region 410 and the intermediate region 430, or in some cases, the coating 407 may be applied on the struts 406 within the second end region 420 and the intermediate region 430. These are merely examples.

[0051] As described above, the stent 400 may include a tubular structure 450 positioned over the intermediate region 430, as shown in FIG. 12. The tubular structure 450 may be formed from a bioabsorbable material and may be configured to maintain the intermediate region 430 in a first compressed form 460. When the intermediate region 430 is in the first compressed form 460, the intermediate region 430 of the tubular framework 405 may include a first inner diameter D1 of about 15 mm. In some cases, the intermediate region 430 may include a first inner diameter D1 of about 10 mm, 12 mm, 18 mm, or any other suitable diameter.

[0052] The bioabsorbable material of the tubular structure 450 may be absorbed by the patient's body through blood flow, other fluids, and / or other natural compositions over a period of time after the stent 400 is implanted in the body. The tubular structure 450 may include a thickness in the range of 0.102 mm to 0.203 mm. In such cases, when the stent 400 is implanted between the gastric wall of the stomach and the jejunum, the bioabsorbable material of the tubular structure 450 may be completely absorbable within 6 weeks of insertion. In some cases, the bioabsorbable material of the tubular structure 450 may be completely absorbable within 2 weeks, 4 weeks, 8 weeks, or any other suitable time frame. In some cases, the time frame for bioabsorption of the tubular structure 450 can be adjusted by varying the thickness of the tubular structure 450 and various additives.

[0053] As shown in FIGS. 14 and 15, when the tubular structure 450 is bioabsorbed, the intermediate region 430 of the tubular framework 405 can radially expand to a second expanded form 470. The expansion of the intermediate region 430 of the tubular framework 405 can be gradual over a period of time due to the bioabsorption of the tubular structure 450, enabling the formation of an anastomosis. The anastomosis is formed around the intermediate region 430 when the intermediate region 430 is in the first compressed form 460. Thus, when the tubular structure 450 collapses and the intermediate region 430 is in the second expanded form 470, the intermediate region 430 may be configured to engage the tissue surface (e.g., the anastomosis) and thereby prevent movement of the stent 400 by exerting a radial force. In some cases, an axially increasing force on the anastomosis can promote faster patency and thereby reduce movement of the stent 400.

[0054] FIGS. 14 and 15 show the exemplary stent of FIGS. 12 and 13 in the second expanded form 470. When in the second expanded form 470, the intermediate region 430 of the tubular framework 405 can expand by 25% when the bioabsorbable tubular structure 450 is absorbed into the body. In some cases, the intermediate region 430 of the tubular framework 405 may expand by 10% - 25%, or any other suitable percentage. In other words, the intermediate region 430 of the tubular framework 405 may include a first inner diameter D1 when in the first compressed form 460 and a second inner diameter D2 when in the second expanded form 470. Thus, when the intermediate region 330 is in the second expanded form 470, the intermediate region 430 may include a second inner diameter D2 of 20 mm. In some cases, the intermediate region 430 may include a second inner diameter D2 of 12.5 mm, 15 mm, 22.5 mm, 12 mm - 23 mm, or any other suitable diameter. In some cases, the second inner diameter D2 may be 25% larger than the first inner diameter D1. In some cases, the second inner diameter D2 may be 10% - 25% larger than the first inner diameter D1. In some cases, the second inner diameter D2 may be 30% larger than the first inner diameter D1.

[0055] Stents 10, 100, 200, 300, 400 may be made of metal, metal alloy, polymer (some examples of which are disclosed below), metal-polymer composite material, ceramic, combinations thereof, etc., or other suitable materials. Some examples of suitable polymers include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, e.g., DELRIN® available from DuPont), polyether block ester, polyurethane (e.g., Polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyether ester (e.g., ARNITEL® available from DSM Engineering Plastics), ether or ester copolymers (e.g., other polyester elastomers such as butylene / poly(alkylene ether) phthalate and / or HYTREL® available from DuPont), polyamide (e.g., DURETHAN® available from Bayer or CRISTAMID™ available from Elf Atochem), elastomeric polyamide, block polyamide / ether, polyether block amide (PEBA, e.g., available under the trade name PEBAX®), ethylene vinyl acetate copolymer (EVA), silicone, polyethylene (PE), MARLEX® high density polyethylene, MARLEX® 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), polyether imide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polyparaphenylene terephthalamide (e.g., KEVLAR®), polysulfone, nylon, nylon 12 (EMS AmericanGRILAMID® available from Grilon, etc., perfluoro(propyl vinyl ether) (PFA), ethyl vinyl alcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS 50A), polycarbonate, ionomer, biocompatible polymer, other suitable materials, or mixtures, combinations, copolymers, polymer / metal composites thereof, etc. In some embodiments, the sheath may be mixed with a liquid crystal polymer (LCP). For example, the mixture may contain up to about 6% LCP.

[0056] In at least some embodiments, some or all of stents 10, 100, 200, 300, 400 may also be doped with a radiopaque material, made of a radiopaque material, or otherwise include a radiopaque material. A radiopaque material is understood to be a material that can generate a relatively bright image with a fluoroscopic screen or another imaging technique during a medical procedure. This relatively bright image helps the user of stents 10, 100, 200, 300, 400 to determine its position. Some examples of radiopaque materials include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, polymer materials loaded with radiopaque fillers, etc. Additionally, other radiopaque marker bands and / or coils may also be incorporated into the design of stents 10, 100, 200, 300, 400 to achieve the same result.

[0057] In some embodiments, a degree of magnetic resonance imaging (MRI) compatibility is imparted to stents 10, 100, 200, 300, 400. For example, stent 10, 100, 200, 300, 400 or a portion thereof may be made of a material that does not substantially distort the image and does not generate substantial artifacts (i.e., gaps in the image). For example, certain ferromagnetic materials may not be suitable because they may generate artifacts in the MRI image. Stent 10 or a portion thereof may be made of a material that can be imaged by an MRI machine. Some materials exhibiting these properties include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS:R30003 such as ELGILOY®, PHYNOX®), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R30035 such as MP35-N™), nitinol, and others.

[0058] It should be understood that the present disclosure is merely exemplary in many respects. Without departing from the scope of the present disclosure, changes can be made in detail, particularly with regard to shape, size, and the arrangement of steps. This may include, within the appropriate scope, the use of any of the features of one exemplary embodiment in other embodiments. The scope of the invention is, of course, defined by the language in which the appended claims are expressed.

Claims

**Claim 1** A radially expanding tubular framework having a radially outer surface, a radially inner surface, a first end region, a second end region, an intermediate region positioned between the first end region and the second end region, and a lumen extending from the first end region to the second end region, and a tubular structure positioned on the intermediate region and configured to maintain the intermediate region in a first compressed form. One of the first end region or the second end region includes a first flange structure, a stent. **Claim 2** The stent according to claim 1, wherein the tubular structure is formed from a bioabsorbable material. **Claim 3** The stent according to claim 2, wherein when the tubular structure is bioabsorbed, the intermediate region of the radially expanding tubular framework radially expands into a second expanded form. **Claim 4** The stent according to claim 2 or 3, wherein the expansion of the intermediate region of the radially expanding tubular framework is gradual over a period of time due to bioabsorption of the tubular structure. **Claim 5** The stent according to any one of claims 2 to 4, wherein the bioabsorbable material of the tubular structure is completely absorbable within 6 weeks from insertion. **Claim 6** The intermediate region of the radially expanding tubular framework includes a first inner diameter when in the first compressed form and a second inner diameter when in the second expanded form, and the second inner diameter is larger than the first inner diameter. The stent according to any one of claims 2 to 5. **Claim 7** The stent according to claim 6, wherein the second inner diameter is 10% to 25% larger than the first inner diameter. **Claim 8** The stent according to claim 6 or 7, wherein the second inner diameter is 25% larger than the first inner diameter. **Claim 9** The stent according to any one of claims 6 to 8, wherein the second inner diameter of the intermediate region is 20 mm. **Claim 10** The stent according to any one of claims 1 to 9, wherein the tubular structure includes a thickness in the range of 0.102 mm to 0.203 mm. **Claim 11** The stent according to any one of claims 1 to 10, wherein the radially expanding tubular framework includes a coating applied on the radially expanding tubular framework. **Claim 12** The other of the first end region or the second end region includes a second flange structure, the stent according to any one of claims 1 to 11.

13. The first flange structure includes an outer diameter of 20 mm to 70 mm, the stent according to any one of claims 1 to 12.

14. The second flange structure includes an outer diameter of 20 mm to 70 mm, the stent according to claim 12 or 13.

15. The first flange structure and the second flange structure include different outer diameters, the stent according to any one of claims 12 to 14.

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