Anti-migration stent

Abstract

An exemplary medical device may include a stent that includes 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. A first flange structure may be positioned near the first end region, and a second flange structure may be positioned near the second end region. One of the first end region or the second end region may include a third flange structure.

Description

Technical Field

[0001] The present disclosure generally relates to the field of implantable medical devices for regulating access through the lumen of a medical device, as well as related systems and methods. More specifically, the present disclosure relates to devices, systems, and methods for controlling and / or altering a lumen 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. If 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 placed 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 comprising 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. A first flange structure may be positioned near the first end region, and a second flange structure may be positioned near the second end region. One of the first end region or the second end region may include a third flange structure.

[0004] Instead of, or in addition to, any of the above embodiments, the stent may be a self-expanding stent. Instead of, or in addition to, any of the above embodiments, the first flange and the second flange may be configured to engage the body tissue non-invasively.

[0005] Instead of, or in addition to, any of the above embodiments, the third flange structure may be positioned near the first end region. Instead of, or in addition to, any of the above embodiments, the second end region may include a fourth flange structure.

[0006] Instead of, or in addition to, any of the above embodiments, the third flange structure may be longitudinally spaced from the first flange structure within a range of 5 mm to 75 mm. Instead of, or in addition to, any of the above embodiments, the third flange structure may be longitudinally spaced from the first flange structure by at least 20 mm.

[0007] Instead of, or in addition to, any of the above embodiments, the first flange structure curves towards the third flange structure such that the first and second ends of the first flange structure engage the third flange structure.

[0008] Instead of, or in addition to, any of the above embodiments, the first flange structure may include a first outer diameter, the second flange structure may include a second outer diameter, the third flange structure may include a third outer diameter, and the first outer diameter, the second outer diameter, and the third outer diameter may be different from each other.

[0009] Instead of, or in addition to, any of the above embodiments, the first, second, and third flange structures each have an outer diameter that is larger than the outer diameter of the intermediate region. Instead of, or in addition to, any of the above embodiments, the third outer diameter may be greater than the first outer diameter and the second outer diameter.

[0010] Instead of, or in addition to, any of the above embodiments, the tubular framework that expands radially may be formed from a woven filament braid. Instead of, or in addition to, any of the above embodiments, the braiding angle of the third flange structure may be different from the braiding angles of the first and second flange structures.

[0011] An exemplary stent may include a radially expanding tubular framework formed from a woven filament braid having 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. A first flange structure having a first outer diameter may be positioned near the first end region, a second flange structure having a second outer diameter may be positioned near the second end region, and a third flange structure having a third outer diameter may be positioned near the first end region. The third flange structure may be longitudinally spaced from the first flange structure, and the third outer diameter may be greater than the first outer diameter and the second outer diameter.

[0012] Instead of, or in addition to, any of the above embodiments, the first outer diameter, the second outer diameter, and the third outer diameter may each be greater than the outer diameter of the intermediate region. Instead of, or in addition to, any of the above embodiments, the braiding angle of the third flange structure may be different from the braiding angles of the first and second flange structures.

[0013] Instead of, or in addition to, any of the above embodiments, the third flange structure may be longitudinally spaced from the first flange structure within a range of 5 mm to 75 mm. Instead of, or in addition to, any of the above embodiments, the third flange structure may be longitudinally spaced from the first flange structure by at least 20 mm.

[0014] An exemplary stent may include a radially expandable tubular framework formed from a woven filament braid having 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. A first flange structure having a first outer diameter may be positioned near the first end region, a second flange structure having a second outer diameter may be positioned near the second end region, and a third flange structure having a third outer diameter may be positioned near the first end region. The third flange structure may be longitudinally spaced from the first flange structure within a range of 5 mm to 75 mm, and the first flange structure may be curved toward the third flange structure such that the first and second ends of the first flange structure are configured to engage the third flange structure.

[0015] Instead of, or in addition to, any of the above embodiments, the third flange structure may be longitudinally spaced from the first flange structure by at least 20 mm. Instead of, or in addition to, any of the above embodiments, the third outer diameter may be greater than the first outer diameter and the second outer diameter.

[0016] The above summary of some embodiments is not intended to describe every disclosed embodiment or every implementation of the present disclosure. The following drawings and detailed description illustrate these embodiments more specifically.

[0017] 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

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

DETAILED DESCRIPTION OF THE INVENTION

[0019] The present disclosure can accept various modified forms and alternative forms, and 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 the present disclosure.

[0020] 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 explicitly shown or not. The term "about" generally refers to a range of numbers that those skilled in the art would consider to be equivalent to the recited values (e.g., having the same function or result). In many cases, the term "about" may include numbers that are rounded to the nearest significant digit.

[0021] The recitation of a numerical range by endpoints includes all numbers within that range (e.g., 1 to 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 dictates 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 dictates otherwise.

[0022] Note that references in this specification to "embodiments", "some embodiments", "other embodiments", etc., indicate that the described embodiments may include one or more features, structures, and / or characteristics. However, such descriptions do not necessarily mean that all embodiments include those features, structures, and / or characteristics. Additionally, when a 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 or not explicitly described, unless there is an express contrary statement.

[0023] According to various principles of the present disclosure, an implantable device can be used to control or adjust the size of a passageway 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 intent to limit). The body passage or lumen may include, but is not limited to, a part of a passage or lumen, a passage or lumen between anatomical structures (such as passages, lumens, cavities, organs, etc.), a passage formed by traversing juxtaposed tissue walls (such as for forming an anastomosis), and the like. The device has a passage or lumen (such terms are used synonymously herein without intent to limit) through the device for use in occluding or blocking or narrowing or closing or constricting or regulating or controlling (such terms and their conjugations are used synonymously herein without intent to limit) the body passage through which the device is positioned. The device may be considered and referred to as an occlusion device or a lumen juxtaposition device or an anastomosis device or a flow regulation device or a flow control device, and such terms and various other alternatives thereof may be used synonymously herein without intent to limit.

[0024] 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 and illustrate exemplary embodiments and are not intended to limit the scope of the invention.

[0025] Figure 1 shows a side 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 expanding tubular framework 13 having a radially outer surface 11 and a radially inner surface 12. The radially expanding 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 expanding 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, 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 complete bypass of the duodenum 40, occlusion of the pylorus 60 (e.g., complete occlusion) may be indicated, 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 juxtaposed 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 has been shown to be useful in 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 to maintain a fluid opening or passageway within a blood vessel, urinary tract, bile duct, tracheobronchial tree, esophagus, or renal tract, or in some cases, may 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 several 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.

[0026] Figure 3 shows a side view of an exemplary stent 100. The stent 100 can be an example of the stent 10 of FIGS. 1 and 2. The stent 100 may be a self-expanding stent 100 and 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, or any other suitable height. In some cases, the outer diameter of the stent 100 may be 18 mm, 22 mm, 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 a distal end region, or the second end region 120 may be a proximal end region. In some cases, the first end region 110 may be a proximal end region, or the second end region 120 may be a distal end region. The first end region 110 may include a first end 111, or 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. In some cases, the intermediate region 130 may define an intermediate point within the tubular framework 105 such that the first end region 110 and the second end region 120 can have the same length. In some cases, as shown in FIG. 3, the intermediate region 130 may be located at a position other than the intermediate point such that the first and second end regions 110, 120 have different lengths.

[0027] 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 intermediate region 130 may be configured to engage the tissue surface, thereby exerting a radial force to assist in preventing movement of the stent 100. The first end region 110 may further include a third flange structure 135 longitudinally spaced from the first flange structure 115. The third flange structure 135 provides an additional radial force to the first end 110 of the stent 100 during peristalsis, thereby preventing movement of the stent 100 from the stomach to the jejunum during peristalsis or turbulent flow caused by digestion of food boluses. The third flange structure 135 may be longitudinally spaced from the first flange structure 115 within a range of 5 mm (millimeters) to 75 mm. In some cases, the third flange structure 135 may be longitudinally spaced from the first flange structure 115 by at least 20 mm. The longitudinal spacing between the first flange structure 115 and the third flange structure 135 may be changed by a desired withdrawal force.

[0028] The first flange structure 115, the second flange structure 125, and the third flange structure 135 can be retaining members configured to assist in maintaining the stent 100 in a fixed position. Thus, the first, second, and third flange structures 115, 125, 135 may include a width (e.g., outer diameter) sufficient to provide a retaining strength. For example, the width of the first, second, and third flange structures 115, 125, 135 may be in the range of 20 to 70 mm (millimeters). In some cases, the first, second, and third flange structures 115, 125, 135 may include a width (e.g., outer diameter) 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, second, and third flange structures 115, 125, 135 may include the same width as each other, as shown in FIG. 3. In some cases, the first and second flange structures 115, 125 may include the same width as each other, and the third flange structure 135 may include a width different from the widths of the first and second flange structures 115, 125. In some cases, the first, second, and third flange structures 115, 125, 135 may all include different widths.

[0029] In some cases, the first, second, and third flange structures 115, 125, 135 may include any of various shapes such as concave, convex, disk-shaped, cylindrical (e.g., having a longer longitudinal extent than shown), or other configurations, and the particular shape and configuration are not limited by the present disclosure. Although it is shown that the first flange structure 115 and the third flange structure 135 are 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 and the third flange structure 135 are 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, the second flange structure 125, or the third flange structure 135).

[0030] The stent 100 may be configured to be implanted between a patient's stomach and jejunum to form an anastomosis. In some cases, the first flange structure 115 may abut against a tissue surface (e.g., the stomach), the second flange structure 125 may abut against a second tissue surface (e.g., the jejunum), and the intermediate region 130 of the stent 100 may extend through openings in the stomach and jejunum and may be configured to engage the tissue surfaces to form an anastomosis. In such cases, the third flange structure may be configured to extend into the stomach. 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 is intended to be permanently implanted within a body lumen, the stent 100 may be made of at least partially biostable material. Examples of biostable metallic materials include stainless steel, tantalum, tungsten, niobium, platinum, nickel-chromium alloys such as Cobalt-Chromium alloys like Elgiloy® and Phynox®, Nitinol (e.g., 55% nickel, 45% titanium), 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 polymer materials include polyamide, polyether block amide, polyethylene, polyethylene terephthalate, polypropylene, polyvinyl chloride, polyurethane, polytetrafluoroethylene, polysulfone, and copolymers, blends, or mixtures, or combinations thereof, but are not necessarily limited thereto.

[0031] The tubular framework 105 may include a number of interconnected struts 106 so as to form a woven filament braided 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 be formed from a metallic material such as, for example, nitinol or a nitinol-containing material, or another nickel-titanium alloy. The struts 106 may include a diameter of, for example, from 0.0762 mm to 0.3556 mm. In some examples, the struts 106 may have a diameter of, for example, about 0.279 mm (about 0.011 inches). The number of struts 106 and the diameter of the struts 106, which may be the same or different, are not limiting, and other numbers of struts 106 and other wire diameters may be appropriately used. Desirably, an even number of struts 106, such as, for example, from about 10 to about 36 struts 106, can be used. In some cases, the tubular framework 105 may include various braiding angles that form a woven filament braided structure. For example, in some cases, the third flange structure 135 may include a braiding angle that is different from the braiding angles of the first flange structure 115 and the second flange structure 125. This can make the third flange structure 135 stiffer and thereby act as an anchor for the stent 100, while the first flange structure 115 may be more flexible and thereby provide additional resistance to peristalsis. In some cases, the braiding angles of the first, second, and third flange structures 115, 125, 135 may be the same. In some cases, the braiding angles of the first, second, and third flange structures 115, 125, 135 may be different.

[0032] The tubular framework 105 may include a coating 107 applied on the struts 106 of the tubular framework 105, and thus, may cover the entire stent 100 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, or 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] The first flange structure 115 may include a first end 116 and a second end 117, the second flange structure 125 may include a first end 126 and a second end 127, and the third flange structure 135 may include a first end 136 and a second end 137. The first ends 116, 126, 136 and the second ends 117, 127, 137 may be formed by bending the struts 106 of the tubular framework 105 to form non-traumatic flange structures (e.g., the first flange structure 115, the second flange structure 125, the third flange structure 135). Thus, the first ends 116, 126, 136 and the second ends 117, 127, 137 may be rounded and non-traumatic such that the first flange structure 115, the second flange structure 125, and the third flange structure 135 are configured to engage non-traumatically with body tissue (e.g., the stomach 20, the jejunum 30).

[0034] FIG. 4 shows an exemplary stent 200 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 be a self-expanding stent 200 and may include a radially expandable tubular framework 205 having a radially outer surface 201 and a radially inner surface (not shown in FIG. 4). The radially inner surface may be regarded as 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 "tubular framework 205". The stent 200 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 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 regarded as an example of the lumen 14 as shown in FIG. 2. In some cases, the first end region 210 may be a distal end region, or the second end region 220 may be a proximal end region. In some cases, the first end region 210 may be a proximal end region, or the second end region 220 may be a distal end region. The first end region 210 may include a first end 211, or 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 define an intermediate point 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 disposed at a position other than the intermediate point such that the first and second end regions 210, 220 have different lengths.

[0035] In some cases, the first end region 210 may include a first flange structure 215 having a first outer diameter, and the second end region 220 may include a second flange structure 225 having a second outer diameter. The intermediate region 230 may be positioned between the first flange structure 215 and the second flange structure 225. The intermediate region 230 may be configured to engage with the tissue surface, thereby exerting a radial force to assist in preventing movement of the stent 200. The first end region 210 may further include a third flange structure 235 having a third outer diameter that is longitudinally spaced from the first flange structure 215 by a first distance as indicated by D1. The third flange structure 235 provides an additional radial force to the first end region 210 of the stent 200, thereby preventing movement of the stent 200 from the stomach 260 to the jejunum 270 during peristalsis or turbulent flow caused by digestion of food masses. The third flange structure 235 may be longitudinally spaced D1 from the first flange structure 215 within a range of 5 mm (millimeters) to 75 mm. In some cases, the third flange structure 235 may be longitudinally spaced D1 from the first flange structure 215 by at least 20 mm. The longitudinal spacing between the first flange structure 215 and the third flange structure 235 may be changed by a desired withdrawal force.

[0036] The first flange structure 215, the second flange structure 225, and the third flange structure 235 can be retaining members configured to assist in maintaining the stent 200 in a fixed position. Thus, the first, second, and third flange structures 215, 225, 235 may include first, second, and third outer diameters, respectively, that are sufficient to provide a retaining strength. For example, the first, second, and third outer diameters of the first, second, and third flange structures 215, 225, 235 may be in the range of 20 mm to 70 mm (millimeters). In some cases, the first, second, and third flange structures 215, 225, 235 may include first, second, and third outer diameters that are larger 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, second, and third outer diameters of the first, second, and third flange structures 215, 225, 235 may be different from each other. In some cases, the third outer diameter of the third flange structure 235 may be larger than the first outer diameter and the second outer diameter of the first flange structure 215 and the second flange structure 225, respectively. In some cases, the first flange structure 215 and the second flange structure 225 may have substantially the same outer diameter, as shown in FIG. 4. For example, the third outer diameter of the third flange structure 235 may include an outer diameter of 55 mm, and the first outer diameter of the first flange structure 215 and the second outer diameter of the second flange structure 225 may include a width of 35 mm. In some cases, the third outer diameter of the third flange structure 235 may include an outer diameter of 45 mm, 60 mm, 65 mm, 70 mm, an outer diameter in the range of 45 mm to 70 mm, or any other suitable width. The first outer diameter of the first flange structure 215 and the second outer diameter of the second flange structure 225 may include an outer diameter of 25 mm, 30 mm, 40 mm, 45 mm, an outer diameter in the range of 25 mm to 45 mm, or any other suitable width. In some cases, as shown in FIG. 4, when the third outer diameter of the third flange structure 235 is larger than the first outer diameter of the first flange structure 215, the risk of movement can be reduced. For example, if the stent 200 begins to move from the stomach 260 into the jejunum 270, the third flange structure 235 will have an outer diameter wide enough to potentially prevent such movement.In some cases, the first, second, and third outer diameters of the first, second, and third flange structures 215, 225, 235 may be the same as each other.

[0037] In some cases, the first, second, and third flange structures 215, 225, 235 may include any of various shapes such as concave, convex, disk-shaped, cylindrical (e.g., having a longer longitudinal range than that shown), or other configurations, etc., and the shape and configuration are not limited by the present disclosure. Although it is shown that the first flange structure 215 and the third flange structure 235 are 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 and the third flange structure 235 are 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, the second flange structure 225, or the third flange structure 235).

[0038] The tubular framework 205 may include a number of interconnected struts 206 so as to form a woven filament braided 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 from 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.

[0039] The first flange structure 215 may include a first end 216 and a second end 217, the second flange structure 225 may include a first end 226 and a second end 227, and the third flange structure 235 may include a first end 236 and a second end 237. The first ends 216, 226, 236 and the second ends 217, 227, 237 may be formed by bending the struts 206 of the tubular framework 205 to form a non-traumatic flange structure (e.g., the first flange structure 215, the second flange structure 225, the third flange structure 235). Thus, the first ends 216, 226, 236 and the second ends 217, 227, 237 may be rounded and non-traumatic so that the first flange structure 215, the second flange structure 225, and the third flange structure 235 are configured to engage the body tissue (e.g., the stomach 20, the jejunum 30) non-traumatically.

[0040] FIG. 5 shows an exemplary stent 300 positioned between a gastric wall 360 (e.g., the stomach) and a portion of the small intestine 370 (e.g., the jejunum). The stent 300 may be a self-expanding stent 300 and may include a radially expandable tubular framework 305 having a radially outer surface 301 and a radially inner surface (not shown in FIG. 5). The radially inner surface may be regarded as an example of the radially inner surface 12 as shown in FIG. 2. The term "radially expandable tubular framework 305" may hereinafter be referred to as the "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. The lumen 340 may be regarded as an example of the lumen 14 as shown in FIG. 2. In some cases, the first end region 310 may be a distal end region, or the second end region 320 may be a proximal end region. In some cases, the first end region 310 may be a proximal end region, or the second end region 320 may be a distal end region. The first end region 310 may include a first end 311, or 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.

[0041] In some cases, the first end region 310 may include a first flange structure 315 having a first outer diameter, and the second end region 320 may include a second flange structure 325 having a second outer diameter. The intermediate region 330 may be positioned between the first flange structure 315 and the second flange structure 325. The intermediate region 330 may be configured to engage the tissue surface, thereby exerting a radial force to assist in preventing movement of the stent 300. The first end region 310 may further include a third flange structure 335 having a third outer diameter that is longitudinally spaced from the first flange structure 315 by a first distance as indicated by D1. The second end region 320 may further include a fourth flange structure 345 that is longitudinally spaced from the second flange structure 325 by a second distance as indicated by D2. The third flange structure 335 and the fourth flange structure 345 each provide additional radial force to the first end region 310 and the second end region 320, respectively, thereby preventing movement of the stent 300 from the stomach 360 to the jejunum 370 during peristalsis or turbulent flow caused by digestion of food masses. The third flange structure 335 may be longitudinally spaced D1 from the first flange structure 315 within a range of 5 mm to 75 mm. In some cases, the third flange structure 335 may be longitudinally spaced D1 from the first flange structure 315 by at least 20 mm. The fourth flange structure 345 may be longitudinally spaced D2 from the second flange structure 325 within a range of 5 mm to 75 mm. In some cases, the fourth flange structure 345 may be longitudinally spaced D2 from the second flange structure 325 by at least 20 mm. The longitudinal spacing between the first flange structure 315 and the third flange structure 335, and the longitudinal spacing between the second flange structure 325 and the fourth flange structure 345 may be varied by a desired extraction force.

[0042] The first flange structure 315, the second flange structure 325, the third flange structure 335, and the fourth flange structure 345 can be retaining members configured to assist in maintaining the stent 300 in a fixed position. Thus, the first, second, third, and fourth flange structures 315, 325, 335, 345 may include first, second, third, and fourth outer diameters, respectively, sufficient to provide a retaining strength. For example, the first, second, third, and fourth outer diameters of the first, second, third, and fourth flange structures 315, 325, 335, 345 may be in the range of 20 mm to 70 mm. In some cases, the first, second, third, and fourth flange structures 315, 325, 335, 345 may include first, second, third, and fourth outer diameters that are greater than the outer diameters of the first end 311, the second end 321, and the intermediate region 330 of the tubular framework 305. In some cases, as shown in FIG. 4, the first, second, third, and fourth outer diameters of the first, second, third, and fourth flange structures 315, 325, 335, 345 may be the same as each other. In some cases, the first, second, third, and fourth outer diameters of the first, second, third, and fourth flange structures 315, 325, 335, 345 may be different from each other. In some cases, the third outer diameter of the third flange structure 335 may be greater than the first outer diameter, the second outer diameter, and the fourth outer diameter of the first flange structure 315, the second flange structure 325, and the fourth flange structure 345, respectively. For example, the third outer diameter of the third flange structure 335 may include an outer diameter of 55 mm, and the first outer diameter of the first flange structure 315, the second outer diameter of the second flange structure 325, and the fourth outer diameter of the fourth flange structure 345 may include a width of 35 mm. In some cases, the third outer diameter of the third flange structure 335 may include an outer diameter of 45 mm, 60 mm, 65 mm, 70 mm, an outer diameter in the range of 45 mm to 70 mm, or any other suitable width. The first outer diameter of the first flange structure 315, the second outer diameter of the second flange structure 325, and the fourth outer diameter of the fourth flange structure 345 may include an outer diameter of 25 mm, 30 mm, 40 mm, 45 mm, or any other suitable width.

[0043] In some cases, the first, second, third, and fourth flange structures 315, 325, 335, 345 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, etc., and the shape and configuration are not limited by the present disclosure. Although it is shown that the first flange structure 315 and the third flange structure 335 are positioned near the first end region 310, and the second flange structure 325 and the fourth flange structure 345 are positioned near the second end region 320, it is also conceivable that the first flange structure 315 and the third flange structure 335 are positioned near the second end region 320, and the second flange structure 325 and the fourth flange structure 345 are 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, the second flange structure 325, the third flange structure 335, or the fourth flange structure 345).

[0044] The tubular framework 305 may include several interconnected struts 306 so as to form a woven filament braided 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 200 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] FIG. 6 shows an exemplary stent 400 positioned between a gastric wall 460 (e.g., the stomach) and a portion of the small intestine 470 (e.g., the jejunum). The stent 400 may be a self-expanding stent 400 and may include a radially expanding tubular framework 405 having a radially outer surface 401 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 expanding tubular framework 405" may hereinafter be referred to as the "tubular framework 405". The stent 400 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 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. The lumen 440 may be considered an example of the lumen 14 as shown in FIG. 2. In some cases, the first end region 410 may be a distal end region, or the second end region 420 may be a proximal end region. In some cases, the first end region 410 may be a proximal end region, or the second end region 420 may be a distal end region. The first end region 410 may include a first end 411, or 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. In some cases, 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.In some cases, as shown in FIG. 6, 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.

[0046] In some cases, the first end region 410 may include a first flange structure 415 having a first outer diameter, and the second end region 420 may include a second flange structure 425 having a second outer diameter. The intermediate region 430 may be positioned between the first flange structure 415 and the second flange structure 425. The intermediate region 430 may be configured to engage the tissue surface, thereby exerting a radial force to assist in preventing movement of the stent 400. The first end region 410 may further include a third flange structure 435 having a third outer diameter that is longitudinally spaced from the first flange structure 415 by a first distance as indicated by D1. The third flange structure 435 provides an additional radial force to the first end region 410 of the stent 400, thereby preventing movement of the stent 400 from the stomach 460 to the jejunum 470 during peristalsis or turbulent flow caused by digestion of food masses. The third flange structure 435 may be longitudinally spaced D1 from the first flange structure 415 within a range of 5 mm to 75 mm. In some cases, the third flange structure 435 may be longitudinally spaced D1 from the first flange structure 415 by at least 20 mm. The longitudinal spacing between the first flange structure 415 and the third flange structure 435 may be changed by a desired extraction force.

[0047] The first flange structure 415, the second flange structure 425, and the third flange structure 435 can be retaining members configured to assist in maintaining the stent 400 in a fixed position. Thus, the first, second, and third flange structures 415, 425, 435 may include first, second, and third outer diameters sufficient to provide retaining strength. For example, the first, second, and third outer diameters of the first, second, and third flange structures 415, 425, 435 may be in the range of 20 mm to 70 mm. In some cases, the first, second, and third flange structures 415, 425, 435 may include first, second, and third outer diameters that are larger than the outer diameters of the first end 411, the second end 421, and the intermediate region 430 of the tubular framework 05. In some cases, the first, second, and third outer diameters of the first, second, and third flange structures 415, 425, 435 may be the same as each other. In some cases, as shown in FIG. 6, the first, second, and third outer diameters of the first, second, and third flange structures 415, 425, 435 may be different from each other. In some cases, the third outer diameter of the third flange structure 435 may be larger than the first outer diameter of the first flange structure 415 and the second outer diameter of the second flange structure 425, respectively. For example, the third outer diameter of the third flange structure 435 may include an outer diameter of 55 mm, and the first outer diameter of the first flange structure 415 and the second outer diameter of the second flange structure 425 may include a width of 35 mm. In some cases, the third outer diameter of the third flange structure 435 may include an outer diameter of 45 mm, 60 mm, 65 mm, 70 mm, an outer diameter in the range of 45 mm to 70 mm, or any other suitable width. The first outer diameter of the first flange structure 415 and the second outer diameter of the second flange structure 425 may include an outer diameter of 25 mm, 30 mm, 40 mm, 45 mm, an outer diameter in the range of 25 mm to 45 mm, or any other suitable width. In some cases, as shown in FIG. 6, when the third outer diameter of the third flange structure 435 is larger than the first outer diameter of the first flange structure 415, the risk of movement can be reduced.For example, when the stent 400 begins to move from the stomach 460 into the jejunum 470, the third flange structure 435 will have an outer diameter wide enough to prevent such movement.

[0048] In some cases, the first, second, and third flange structures 415, 425, 435 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, etc., and the shape and configuration are not limited by the present disclosure. Although it is shown that the first flange structure 415 and the third flange structure 435 are positioned near the first end region 410 and the second flange structure 425 is positioned near the second end region 420, it is also conceivable that the first flange structure 415 and the third flange structure 435 are positioned near the second end region 420 and the second flange structure 425 is positioned near the first end region 10. In some cases, it is conceivable that the tubular framework 405 includes only one flange structure (e.g., the first flange structure 415, the second flange structure 425, or the third flange structure 435).

[0049] The tubular framework 405 may include several interconnected struts 406 so as to form a woven filament braided 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, and 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.

[0050] The first flange structure 415 may include a first end 416 and a second end 417, the second flange structure 425 may include a first end 426 and a second end 427, and the third flange structure 435 may include a first end 436 and a second end 437. The first ends 416, 426, 436 and the second ends 417, 427, 437 may be formed by bending the struts 406 of the tubular framework 405 to form a non-traumatic flange structure (e.g., the first flange structure 415, the second flange structure 425, the third flange structure 435). Thus, the first ends 416, 426, 436 and the second ends 417, 427, 437 may be rounded and non-traumatic so that the first flange structure 415, the second flange structure 425, and the third flange structure 435 are configured to engage non-traumatically with body tissues (e.g., the stomach 20, the jejunum 30).

[0051] In the example shown in FIG. 6, the first end 416 of the first flange structure 415 and the second end 417 of the first flange structure 415 may be curved toward the third flange structure 435 (and away from the second flange structure 425) such that the first end 416 and the second end 417 of the first flange structure 415 engage the surface of the third flange structure 435. When the first end 416 and the second end 417 engage the third flange structure 435, the third flange structure 435 provides resistance during peristalsis, thereby preventing movement of the stent 400 from the stomach 460 into the jejunum 470.

[0052] Stents 10, 100, 200, 300, 400 may be made from metals, metal alloys, polymers (some examples of which are disclosed below), metal-polymer composites, ceramics, combinations thereof, 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.

[0053] 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 fluoroscopy 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 their 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.

[0054] In some embodiments, a degree of magnetic resonance imaging (MRI) compatibility is imparted to stents 10, 100, 200, 300, 400. For example, stents 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 within the image). For example, certain ferromagnetic materials may not be suitable as they may have the potential to generate artifacts in the MRI image. Stents 10, 100, 200, 300, 400, 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, platinum, and others.

[0055] It should be understood that the present disclosure is merely exemplary in many respects. Changes can be made in detail, particularly with regard to shape, size, and the arrangement of steps, without exceeding the scope of the present disclosure. 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 of the appended claims.

Claims

1. A radially expandable tubular framework having 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, a first flange structure positioned near the first end region, a second flange structure positioned near the second end region, and a stent, wherein one of the first end region or the second end region includes a third flange structure.

2. The stent according to claim 1, wherein the first flange and the second flange are configured to engage non-invasively with body tissue.

3. The first flange structure includes a first outer diameter, the second flange structure includes a second outer diameter, the third flange structure includes a third outer diameter, and at least one of the first outer diameter, the second outer diameter, and the third outer diameter is different from the others. The stent according to claim 1 or 2.

4. The stent according to claim 3, wherein the third outer diameter is larger than the first outer diameter and the second outer diameter.

5. The stent according to any one of claims 1 to 4, wherein each of the first, second, and third flange structures has an outer diameter larger than the outer diameter of the intermediate region.

6. The stent according to any one of claims 1 to 5, wherein the radially expandable tubular framework is formed from a woven filament braid.

7. The stent according to claim 6, wherein the braiding angle of the third flange structure is different from the braiding angles of the first and second flange structures.

8. The stent according to any one of claims 1 to 7, wherein the third flange structure is positioned near the first end region.

9. The stent according to claim 8, wherein the third flange structure is longitudinally spaced from the first flange structure within a range of 5 mm to 75 mm.

10. The stent according to claim 8, wherein the third flange structure is longitudinally spaced from the first flange structure by at least 20 mm.

11. The stent according to claim 8, wherein the first flange structure is curved toward the third flange structure such that the first and second ends of the first flange structure are configured to engage with the third flange structure.

12. The stent according to any one of claims 1 to 11, wherein the second end region includes a fourth flange structure. **Claim 13** The stent according to claim 12, wherein the fourth flange structure is longitudinally spaced from the second flange structure within a range of 5 mm to 75 mm. **Claim 14** The stent according to any one of claims 1 to 13, wherein the intermediate region is configured to engage the tissue surface to exert a radial force for preventing movement of the stent. **Claim 15** The stent according to any one of claims 1 to 14, wherein the radially expandable tubular framework includes a coating applied on the radially expandable tubular framework.

Images