Removable stent

An illustrative endoluminal implant having an elongated tubular member. The elongate tubular member having a proximal stent, a distal stent and an interconnecting sleeve. The proximal stent tapers from a first outer diameter adjacent the proximal end region to a second smaller outer diameter adjacent the distal end region. The distal stent has an outer diameter less than the first outer diameter of the proximal stent. The interconnecting sleeve is collapsible in response to an applied radial force such that the sleeve is positionable across a natural valve or sphincter.

TECHNICAL FIELD

The present disclosure relates generally to methods and apparatuses for various digestive ailments. More particularly, the disclosure relates to removable stents for extending through a valved region.

BACKGROUND

Implantable stents are devices that are placed in a tubular body structure, such as a blood vessel, esophagus, trachea, biliary tract, colon, intestine, stomach or body cavity, to provide support and to maintain the structure open. These devices are manufactured by any one of a variety of different manufacturing methods and may be used according to any one of a variety of methods. Of the known medical devices, delivery systems, and methods, each has certain advantages and disadvantages. There is an ongoing need to provide alternative medical devices and delivery/retrieval devices as well as alternative methods for manufacturing and using medical devices and delivery/retrieval devices.

SUMMARY

This disclosure is directed to several alternative designs, materials, methods of manufacturing medical device structures and associated uses thereof, such as stents for preventing leaks after an anastomosis surgery and/or treating various gastro-intestinal, digestive, or other ailments.

One illustrative embodiment is an implant including a first region, a second region and a third region. The first region has a proximal end region and a distal end region. The first region includes a flared proximal stent frame tapering radially inward in a distal direction. The second region has a proximal end region and a distal end region. The second region includes a flexible sleeve extending distally from the distal end region of the first region. The third region has a proximal end region and a distal end region. The third region includes a distal stent frame having an outer diameter less than an outer diameter of the flared proximal stent frame adjacent the proximal end region of the first region and extending distally from the distal end region of the second region. The flexible sleeve is configured to extend across a natural valve or sphincter and collapse upon itself in response to a radially applied force.

Additionally or alternatively, in another embodiment the implant includes a first retrieval suture configured to at least partially collapse the implant for removal from a body lumen.

Additionally or alternatively, in another embodiment the first retrieval suture is interwoven with the flared proximal stent frame and the distal stent frame.

Additionally or alternatively, in another embodiment the first retrieval suture includes a first suture loop interwoven with the flared proximal stent frame adjacent the proximal end region of the first region, a second suture loop interwoven with the distal stent adjacent the proximal end region of the third region, and a connecting suture portion extending between and coupled to the first and second suture loops.

Additionally or alternatively, in another embodiment a proximal force exerted on the first retrieval suture is configured to partially collapse the flared proximal stent frame adjacent the proximal end region of the first region.

Additionally or alternatively, in another embodiment once the outer diameter of the flared proximal stent frame adjacent the proximal end region of the first region is partially collapsed, the distal stent frame is configured to begin collapsing simultaneously with further collapsing of the proximal stent frame.

Additionally or alternatively, in another embodiment the connecting suture portion includes a slack portion which is configured to be drawn taut as the flared proximal stent frame is partially collapsed before the distal stent frame begins to collapse.

Additionally or alternatively, in another embodiment the first retrieval suture includes a first suture loop interwoven with the distal stent frame adjacent the distal end region of the third region, a second suture loop interwoven with the flared proximal stent frame adjacent the distal end region of the first region, and a connecting suture portion extending between and coupled to the first and second suture loops.

Additionally or alternatively, in another embodiment a distal force exerted on the first retrieval suture is configured to partially collapse the distal stent frame adjacent the distal end region of the third region.

Additionally or alternatively, in another embodiment the connecting suture portion includes a slack portion which is configured to be drawn taut as the distal stent frame is partially collapsed before the flared proximal stent frame begins to collapse.

Additionally or alternatively, in another embodiment the implant includes a second retrieval suture.

Additionally or alternatively, in another embodiment the second retrieval suture is interwoven with the flared proximal stent frame and the distal stent frame.

Additionally or alternatively, in another embodiment at least one of the first or second retrieval sutures is configured to at least partially collapse the flared proximal stent frame prior to collapsing the distal stent frame.

Additionally or alternatively, in another embodiment at least one of the first or second retrieval sutures is configured to at least partially collapse the distal stent frame prior to collapsing the flared proximal stent frame.

Additionally or alternatively, in another embodiment the flared proximal stent frame has an outer profile configured to conform to an outlet of a stomach.

Additionally or alternatively, in another embodiment the outer diameter of the flared proximal stent frame adjacent the proximal end region of the first region is in the range of about 25 millimeters (mm) to about 50 mm.

Additionally or alternatively, in another embodiment the outer diameter of the distal stent frame is in the range of about 15 millimeters (mm) to about 25 mm.

Another illustrative embodiment is an implant including an elongated tubular member. The elongated tubular member includes a proximal stent, a flexible sleeve, and a distal stent.

The proximal stent has a proximal end region and a distal end region. The proximal stent tapers from a first outer diameter adjacent the proximal end region to a second smaller outer diameter adjacent the distal end region. The flexible sleeve has a proximal end region and a distal end region. The flexible sleeve extends distally from the distal end region of the flared proximal stent. The distal stent has a proximal end region and a distal end region. The distal stent has an outer diameter less than the first outer diameter of the proximal stent and extends distally from the distal end region of the flexible sleeve. A first retrieval suture is interwoven with the proximal stent and the distal stent. The flexible sleeve is configured to extend across a natural valve or sphincter and collapse upon itself in response to an applied radial force.

Additionally or alternatively, in another embodiment the proximal stent is configured to be positioned at a gastric outlet of a stomach and the flexible sleeve is configured to be positioned across a pyloric sphincter.

Additionally or alternatively, in another embodiment the applied radial force is a natural action of the pyloric sphincter.

Additionally or alternatively, in another embodiment the first retrieval suture is configured to at least partially collapse the proximal stent prior to begin collapsing the distal stent.

Additionally or alternatively, in another embodiment the first retrieval suture is configured to at least partially collapse the distal stent prior to begin collapsing the proximal stent.

Another illustrative embodiment is a method of removing or repositioning an endoluminal implant. The method includes actuating an end of a retrieval suture in a first direction. The retrieval suture is interwoven within an end region of a first stent of an endoluminal implant and an end region of a second stent of the endoluminal implant. The first and second stents are separated and connected by a flexible polymeric sleeve. The end region of the first stent is configured to partially collapse before the end of the second stent begins to collapse.

Additionally or alternatively, in another embodiment the retrieval suture includes a first circumferential loop extending around the end region of the first stent, a second circumferential loop extending around the end of the second stent, and a connecting suture portion extending between the first circumferential loop and the second circumferential loop, wherein a slack portion of the connecting suture portion is drawn taut as the end region of the first stent is partially collapsed before the end of the second stent begins to collapse.

Additionally or alternatively, in another embodiment the first stent is connected to the second stent only by the flexible polymeric sleeve.

The above summary of exemplary embodiments is not intended to describe each disclosed embodiment or every implementation of the present disclosure.

DETAILED DESCRIPTION

Although some suitable dimensions, ranges, and/or values pertaining to various components, features and/or specifications are disclosed, one of the skill in the art, incited by the present disclosure, would understand desired dimensions, ranges and/or values may deviate from those expressly disclosed.

For purposes of this disclosure, “proximal” refers to the end closer to the device operator during use, and “distal” refers to the end further from the device operator during use.

It is noted that references in the specification to “an embodiment”, “some embodiments”, “other embodiments”, etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with one embodiment, it should be understood that such feature, structure, or characteristic may also be used connection with other embodiments whether or not explicitly described unless cleared stated to the contrary.

Gastric outlet obstruction (GOO) is the clinical and pathophysiological consequence of any disease process that produces a mechanical impediment to gastric emptying. The presence of GOO can be classified into disease conditions that affect the antrum and pylorus that lead to pyloric dysfunction or disease conditions of the proximal duodenum that restrict efferent flow. Clinical conditions such as peptic ulcer disease (PUD), pyloric stenosis, and gastric polyps represent etiologies for the former with pancreatic carcinoma, ampullary cancer, duodenal cancer, cholangiocarcinomas representing etiologies for the latter. In some instances, GOO may be directly treated through stenting the location using gastrointestinal (GI) self-expanding stents. However, placing a stent across the pyloric valve may leave the pylorus in a continually open position. However, this may result in gastric leakage into the duodenum. Alternative stent designs are desired to allow the immediate blockage to be opened while allowing for natural pyloric function to be retained.

FIG.1illustrates a side view of an illustrative endoluminal implant10including a plurality of regions, including, a first or proximal region12, a second or intermediate region14, a third or intermediate region16, and a fourth or distal region18. While the illustrative implant10is shown and described as having four regions12,14,16,18, it is contemplated the implant10may include any number of regions desired, such as, but not limited to, one, two, three, four, or more. Further, the regions12,14,16,18may be any combination of structures and materials desired. In some cases, the implant10may include features (e.g., anti-migration flares, fixation spikes, sutures, etc.) to prevent distal/proximal displacement and/or migration of the implant10, once the implant10is positioned and expanded in the body lumen. The implant10may include a lumen48extending entirely through the length of the implant10, such as from a proximal end24of the first region12to a distal end46of the fourth region18. In some cases, the first region12may take the form of a stent20including an elongated tubular stent frame22defining a lumen. The stent20may be may be entirely, substantially, or partially covered with a polymeric covering, such as a coating (not explicitly shown). The covering may be disposed on an inner surface and/or outer surface of the stent20, as desired. When so provided a polymeric covering may reduce or eliminate tissue ingrowth and/or reduce food impaction through interstices of the stent20into the lumen. It is contemplated that leaving an outer rim or a portion of the surface uncovered, an area of hyperplasia can be generated which would create a seal. The stent20may include regions of differing diameters. For example, the stent20may include a flared (e.g., enlarged relative to other portions of the stent20) proximal end region24tapering radially inward to a distal end region. While not explicitly shown, the stent20may include regions of constant diameter or increasing diameters (e.g., in the distal direction), if so desired. The stent frame22may be expandable between a radially collapsed delivery configuration and a radially expanded deployed configuration. The expanded configuration may secure the implant10at the desired location in a body lumen.

In some cases, the third region16may take the form of a stent28including an elongated tubular stent frame30defining a lumen. The stent28may be may be entirely, substantially or partially, covered with a polymeric covering, such as a coating (not explicitly shown). The covering may be disposed on an inner surface and/or outer surface of the stent28, as desired. When so provided a polymeric covering may reduce or eliminate tissue ingrowth and/or reduce food impaction through interstices of the stent28into the lumen. The stent28may have a uniform outer diameter from its proximal end region32to its distal end region34. However, the stent28may include regions of differing diameters if so desired. The stent frame30may be expandable between a radially collapsed delivery configuration and a radially expanded deployed configuration. The expanded configuration may secure the implant10at the desired location in a body lumen. While not explicitly shown, in some embodiments, the distal stent28may extend distally to a distal end of the implant10. Some additional but non-limiting alternative configurations are shown and described with respect toFIGS.2-5.

The stent frames22,30may have a woven structure, fabricated from a number of filaments. In some embodiments, the stent frames22,30may be knitted with one filament, as is found, for example, in the ULTRAFLEX™ stents, made and distributed by Boston Scientific Corp. In other embodiments, the stent frames22,30may be braided with several filaments, as is found, for example, in the WALLFLEX®, WALLSTENT®, and POLYFLEX® stents, made and distributed by Boston Scientific Corp. In yet another embodiment, the stent frames22,30may be of a knotted type, such the PRECISION COLONIC™ stents made by Boston Scientific Corp. In still another embodiment, the stent frames22,30may be laser cut, such as the EPIC™ stents made by Boston Scientific Corp. It is contemplated that the stent frames22,30may be formed having the same structure as one another or having a different structure from one another.

It is contemplated that the stent frames22,30can be made from a number of different materials such as, but not limited to, metals, metal alloys, shape memory alloys and/or polymers, as desired, enabling the stents20,28to be expanded into shape when accurately positioned within the body. The material of the stent frames22,30may be the same or different, as desired. In some instances, the material may be selected to enable the stents20,28to be removed with relative ease as well. For example, the stent frames22,30can be formed from alloys such as, but not limited to, nitinol and ELGILOY®. Depending the on material selected for construction, the stents20,28may be self-expanding (i.e., configured to automatically radially expand when unconstrained). In some embodiments, fibers may be used to make the stent frames22,30, which may be composite fibers, for example, having an outer shell made of nitinol having a platinum core. It is further contemplated the stent frames22,30may be formed from polymers including, but not limited to, polyethylene terephthalate (PET). In some embodiments, the stents20,28may be self-expanding while in other embodiments, the stents20,28may be expanded by an expansion device (such as, but not limited to a balloon inserted within a lumen48of the implant10). As used herein the term “self-expanding” refers to the tendency of the stent to return to a preprogrammed diameter when unrestrained from an external biasing force (for example, but not limited to a delivery catheter or sheath).

One or both of the stents20,28may include a one-way valve, such as an elastomeric slit valve or duck bill valve, positioned within the lumen48thereof to prevent retrograde flow of fluid or other material, such as gastrointestinal fluids.

In some cases, the second portion14may take the form of a proximal flexible sleeve36and the fourth portion18may take the form of a distal flexible sleeve42. The proximal sleeve36may extend between the distal end of the proximal stent20and the proximal end of the distal stent28. For example, the proximal sleeve36may be connected, affixed, or secured to the distal end region26of the first or proximal stent20adjacent to a proximal end region38of the sleeve36. The proximal sleeve36may also be connected, affixed, or secured to the proximal end region32of the second or distal stent28adjacent to a distal end region40of the proximal sleeve36. In some cases, the proximal sleeve36may overlap a portion or all of the proximal stent20and/or a portion or all of the distal stent28. In some instances, the proximal sleeve36may be devoid of any structural components tending to hold the lumen48through the sleeve36open, thus allowing the sleeve36to collapse inward upon itself when subjected to the force of the pyloric valve closing off the lumen48. The distal sleeve42may be connected, affixed, or secured to the distal end region44of the second or distal stent28adjacent to a proximal end region44of the sleeve42and extend distally to a distal end region46. In some cases, the distal sleeve42may overlap a portion or all of the distal stent28. It is contemplated that the sleeve36,42may be formed as individual flexible membranes or as a single unitary structure, as desired. In some embodiments, the sleeves36,42may extend partially, substantially, or all of the length of the implant10and cover all other portions (exterior surface and/or interior surface) of the implant10, including the stents20,28. Said differently, while the regions12,14,16,18have been described as a stent20,28or a sleeve36,42, each region may include one or both of a frame structure and flexible sleeve structure. The sleeves36,42may be secured to one or both of the stents20,28by an adhesive or other methods known in the art, including by not limited to thermal methods, mechanical methods, etc.

The sleeves36,42may each have an elongated, tubular shape defining a lumen. The lumen of the stents20,28and the flexible sleeves36,42may be fluidly connected to form the lumen48of the implant10. It is contemplated that one or more of the regions12,14,16,18of the implant10may include more than one lumen, as desired. The sleeves36,42may be a thin flexible membrane that readily collapses on itself. For example one or both of the sleeves may be configured to collapse upon itself under the applied radial force exerted by a natural valve or sphincter when the implant10is deployed in a body lumen having a natural valve or sphinctor. However, one or both of the sleeves36,42may be provided with a radial support to hold it in the expanded configuration. Some examples and discussion of illustrative supports may be found in Patent Application No. 62/419,707, filed on Nov. 9, 2016, titled DEPLOYABLE SLEEVES AND RELATED METHODS, the disclosure of which is incorporated herein by reference.

In further detail, the implant10may be generally cylindrical in shape, although this is not required, substantially flexible, and sized appropriately for a convenient accommodation within the digestive tract. It is contemplated that various shapes, sizes and designs of the implant may be constructed depending on the size and geometry of the cavities where the implant10has to be placed. In various examples, the implant10may have a length between 3-12 inches, 3-6 inches, 0.5-20 feet (0.15-6.1 meters), between 3-5 feet (0.9-1.5 meters), or about 2-4 feet (0.6-1.2 meters). However, the implant10may have a length of less than 0.5 feet (0.15 meters) or greater than 20 feet (6.1 meters) in some instances.

In one illustrative example, the implant10may be sized to be positioned within the outlet of the stomach, extend across the pylorus and into the duodenum to treat, for example, gastric outlet obstruction. In such an example, the proximal stent20may be sized to prevent the implant10from migrating distally through the stomach outlet. For example, the proximal end region24of the proximal stent20may have an outer diameter50in the range of about 25 millimeters (mm) to about 50 mm. It is contemplated that the shape of the proximal stent20may be formed to match or generally conform to the shape of the stomach exit. The proximal sleeve36may be configured to extend across the pylorus and may have a length54in the range of about 6 mm to about 15 mm. The distal stent28and the distal sleeve42may be sized to be positioned within the duodenal bulb and duodenum, respectively, and may have an outer diameter52in the range of about 15 mm to about 25 mm. The distal stent28and the distal sleeve42may together have a length56in the range of about 60 mm to about 150 mm. When the distal stent28extends distally to a distal end of the implant10, the distal stent28may have a length56in the range of about 60 mm to about 150 mm. This is just an example. It is contemplated that the proximal sleeve36and/or the distal sleeve42may be positioned across other valved or sphincter regions with the proximal and/or distal stents20,28sized and shaped for the adjacent anatomy.

Once implanted in a patient, the stents20,28may exert a radially outward force to help secure the implant10to the body lumen. The implant10may be positioned in the antrum-pyloric-duodenum, esophagus, the gastro-esophageal junction (GEJ) region (e.g., at or near the cardia with the sleeve24extending into the esophagus), or at or near the pylorus with the sleeve24extending through the stomach or other portions of the gastro-intestinal system. In one example, the implant10may be positioned such that the proximal stent20is positioned at the stomach outlet with the proximal sleeve36bridging the pylorus. The flared structure of the proximal stent20may use the stomach to anchor the implant10and act as an anti-migration mechanism for the implant10. For example, the large outer diameter50of the proximal end24of the proximal stent20may engage the stomach outlet to prevent or limit movement of the implant10. The distal stent28may be placed within the duodenal bulb and the distal sleeve42may extend into the duodenum. The proximal sleeve36may be coupled to both the proximal stent20and the distal stent28such that a relative position of each section is fixed.

In some instances, the function of the pyloric valve may not have been impacted or degraded by the disease state which has caused the gastric outlet obstruction. In such an instance, it may be desirable to open the obstruction while still allowing for normal function of the pyloric valve. As described above, the proximal sleeve36may be formed from a flexible material. In other words, the proximal sleeve36may be free from any structure configured to exert a radially outward force on the surrounding tissue and may collapse upon itself under the applied radial force exerted by the natural valve or sphincter. This may allow the pyloric valve to function in a natural manner (e.g., to open and close). The distal stent28may be positioned adjacent to the gastric outlet obstruction. The stent frame30of the distal stent28may be constructed with sufficient radial force (e.g., to exert a sufficient radially outward force) to open the obstruction caused by the disease state.

FIG.2illustrates a side view of another illustrative implant100including a plurality of regions, including, a first or proximal region102, a second or intermediate region104, and a third or distal region106. The illustrative implant100may be similar in form and function to the implant10described above. While the illustrative implant100is shown and described as having three regions102,104,106, it is contemplated the implant100may include any number of regions desired, such as, but not limited to, one, two, three, four, or more. Further, the regions102,104,106may be any combination of structures and materials desired. In some cases, the implant100may include features (e.g., anti-migration flares, fixation spikes, sutures, etc.) to prevent distal/proximal displacement and/or migration of the implant100, once the implant100is positioned and expanded in the body lumen. The implant100may include a lumen108extending from a proximal end114of the first region102to a distal end124of the third region106.

In some cases, the first region102may take the form of a stent110including an elongated tubular stent frame112defining a lumen which may be similar in form and function to the proximal stent20described above. The stent110may be entirely, substantially or partially, covered with a polymeric covering, such as a coating (not explicitly shown). The covering may be disposed on an inner surface and/or outer surface of the stent frame112, as desired. When so provided a polymeric covering may reduce or eliminate tissue ingrowth and/or reduce food impaction. The stent110may include regions of differing diameters. For example, the stent110may include a flared (e.g., enlarged relative to other portions of the stent110) proximal end region114tapering radially inward in a distal direction to a distal end region116. While not explicitly shown, the stent110may include regions of constant diameter or increasing diameters (e.g., increasing in the distal direction), if so desired. The stent frame112may be expandable between a radially collapsed delivery configuration and a radially expanded deployed configuration. The expanded configuration may secure the implant100at the desired location in a body lumen.

In some cases, the third region106may take the form of a stent118including an elongated tubular stent frame120defining a lumen which may be similar in form and function to the distal stent28described above. The stent118may be entirely, substantially or partially, covered with a polymeric covering, such as a coating (not explicitly shown). The covering may be disposed on an inner surface and/or outer surface of the stent frame120, as desired. When so provided a polymeric covering may reduce or eliminate tissue ingrowth and/or reduce food impaction. The stent118may have a uniform outer diameter from its proximal end region122to its distal end region124. However, the stent118may include regions of differing diameters if so desired. The stent frame120may be expandable between a radially collapsed delivery configuration and a radially expanded deployed configuration. The expanded configuration may secure the implant100at the desired location in a body lumen. While not explicitly shown, in some embodiments, the distal stent118may extend distally to a distal end to of the implant100.

In some cases, the second portion104may take the form of a flexible sleeve126. The sleeve126may extend between the distal end of the proximal stent110and the proximal end of the distal stent118. For example, the sleeve126may be connected, affixed, or secured to the distal end region116of the first or proximal stent110adjacent to a proximal end region128of the sleeve126. The sleeve126may also be connected, affixed, or secured to the proximal end region122of the second or distal stent118adjacent to a distal end region130of the sleeve126. In some cases, the sleeve126may overlap a portion or all of the proximal stent110and/or a portion or all of the distal stent118. Said differently, the sleeve126may extend from the proximal end region114of the proximal stent110to the distal end region124of the distal stent118such that the implant100is fully covered. Alternatively, and/or additionally, one or both of the proximal stent110and the distal stent118may be covered with a material or structure different from the sleeve126to provide a fully covered implant100. The sleeve126may be secured to one or both of the stents110,118by an adhesive or other methods known in the art, including by not limited to thermal methods, mechanical methods, etc.

The sleeve126may have an elongated, tubular shape defining a lumen which may be similar in form or function to the sleeves36,42described above. The lumen of the stents110,118and the flexible sleeve126may be fluidly connected to form the lumen108of the implant100. It is contemplated that one or more of the regions102,104,106of the implant100may include more than one lumen, as desired. The sleeve126may be a thin flexible membrane that readily collapses on itself. However, in some instances, the sleeve126may be provided with a radial support.

The sleeve126may include one or more longitudinally extending slots132extending through a thickness of the sleeve126. The removal of material to form the slots132may allow for a connecting element to remain between the proximal stent110and the distal stent118while increasing the deformability and/or moveability of the sleeve126. Thus, when the sleeve126is positioned across a valve or sphincter, such as, but not limited to the pyloric valve, the reduced amount of material placed across the valve region may further allow for normal valve function. The sleeve126may include any number of longitudinally extending slots132desired, such as, but not limited to one, two, three, four, or more. The slots132may be positioned uniformly about a circumference of the sleeve126(e.g., having a uniform distance between adjacent slots132) or eccentrically about a circumference of the sleeve126(e.g., having an unequal distant between adjacent slots132). While the slots132have been described as extending longitudinally (e.g., along a longitudinal axis of the implant100), it is contemplated that the slots132may extend along non-parallel angles relative to the longitudinal axis of the implant100. For example, the slots132may extend in a helical manner about a circumference of the sleeve126.

In one illustrative example, the implant100may be sized to be positioned within the outlet of the stomach, extend across the pylorus and into the duodenum to treat, for example, gastric outlet obstruction. In such an example, the proximal stent110may be sized to prevent implant100from migrating distally through the stomach outlet. For example, the proximal end region114of the proximal stent110may have an outer diameter134in the range of about 25 millimeters (mm) to about 50 mm. It is contemplated that the shape of the proximal stent110may be formed to match or generally conform to the shape of the stomach exit. The sleeve126may be configured to extend across the pylorus and may have a length136in the range of about 6 mm to about 15 mm. The distal stent118may be sized to be positioned within the duodenal bulb and duodenum, respectively, and may have an outer diameter138in the range of about 15 mm to about 25 mm. The distal stent118may have a length140in the range of about 60 mm to about 150 mm. This is just an example. It is contemplated that the sleeve126may be positioned across other valved or sphincter regions with the proximal and/or distal stents110,118sized and shaped for the adjacent anatomy.

Once implanted in a patient, the stents110,118may exert a radially outward force to help secure the implant100to the body lumen. The implant100may be positioned in the esophagus, the gastro-esophageal junction (GEJ) region, or at or near the pylorus with the sleeve114extending through the stomach or other portions of the gastro-intestinal system. In one example, the implant100may be positioned such that the proximal stent110is positioned at the stomach outlet with the sleeve126bridging the pylorus. The flared structure of the proximal stent110may use the stomach to anchor the implant100and act as an anti-migration mechanism for the implant100. For example, the large outer diameter134of the proximal end114of the proximal stent110may engage the stomach outlet to prevent or limit movement of the implant100. The distal stent118may be placed within the duodenal bulb and may extend into the duodenum. The sleeve126may be coupled to both the proximal stent110and the distal stent118such that a relative position of each section is fixed.

In some instances, the function of the pyloric valve may not have been impacted or degraded by the disease state which has caused the gastric outlet obstruction. In such an instance, it may be desirable to open the obstruction while still allowing for normal function of the pyloric valve. As described above, the sleeve126may be formed from a flexible material which may be made more flexible or pliable through the addition of slots132. In other words, the sleeve126, and thus the length of the intermediate region104between the proximal stent110and the distal stent118, may be free from any structure configured to exert a radially outward force on the surrounding tissue. This may allow the pyloric valve to function in a natural manner (e.g., to open and close). The distal stent118may be positioned adjacent to the gastric outlet obstruction. The stent frame120of the distal stent118may be constructed with sufficient radial force (e.g., to exert a sufficient radially outward force) to open the obstruction caused by the disease state.

FIG.3illustrates a side view of another illustrative implant150including a plurality of regions, including, a first region152, a second region154, and a third region156. The illustrative implant150may be similar in form and function to the implant10described above. While the illustrative implant150is shown and described as having three regions152,154,156, it is contemplated the implant150may include any number of regions desired, such as, but not limited to, one, two, three, four, or more. Further, the regions152,154,156may be any combination of structures and materials desired. In some cases, the implant150may include features (e.g., anti-migration flares, fixation spikes, sutures, etc.) to prevent distal/proximal displacement and/or migration of the implant150, once the implant150is positioned and expanded in the body lumen. The implant150may include a lumen158extending from a proximal end164of the first region152to a distal end174of the third region156.

In some cases, the first region152may take the form of a stent160including an elongated tubular stent frame162defining a lumen which may be similar in form and function to the proximal stent20described above. The stent160may be entirely, substantially or partially, covered with a polymeric covering, such as a coating (not explicitly shown). The covering may be disposed on an inner surface and/or outer surface of the stent frame162, as desired. When so provided a polymeric covering may reduce or eliminate tissue ingrowth and/or reduce food impaction. The stent160may include regions of differing diameters. For example, the stent160may include a flared (e.g., enlarged relative to other portions of the stent160) proximal end region164tapering radially inward in a distal direction to a distal end region166. While not explicitly shown, the stent160may include regions of constant diameter or increasing diameters (e.g., increasing in the distal direction), if so desired. The stent frame162may be expandable between a radially collapsed delivery configuration and a radially expanded deployed configuration. The expanded configuration may secure the implant150at the desired location in a body lumen.

In some cases, the third region156may take the form of a stent168including an elongated tubular stent frame170defining a lumen which may be similar in form and function to the distal stent28described above. The stent168may be entirely, substantially or partially, covered with a polymeric covering, such as a coating (not explicitly shown). For example, a partial covering could be used to cause hyperplasia for fixation or, for example, for biliary, or other, access. The covering may be disposed on an inner surface and/or outer surface of the stent frame170, as desired. When so provided a polymeric covering may reduce or eliminate tissue ingrowth and/or reduce food impaction. The stent168may have a uniform outer diameter from its proximal end region172to its distal end region174. However, the stent168may include regions of differing diameters if so desired. The stent frame170may be expandable between a radially collapsed delivery configuration and a radially expanded deployed configuration. The expanded configuration may secure the implant150at the desired location in a body lumen. While not explicitly shown, in some embodiments, the distal stent168may extend distally to a distal end of the implant150.

In some cases, the second portion154may take the form of a flexible sleeve176. The sleeve176may extend between the distal end of the proximal stent160and the proximal end of the distal stent168. For example, the sleeve176may be connected, affixed, or secured to the distal end region166of the first or proximal stent160adjacent to a proximal end region178of the sleeve176. The sleeve176may also be connected, affixed, or secured adjacent or distal to the proximal end region172of the second or distal stent168adjacent to a distal end region180of the sleeve176. In some cases, the sleeve176may overlap a portion or all of the proximal stent160and/or a portion of the distal stent168. Said differently, the sleeve176may extend from the proximal end region164of the proximal stent160to a location proximal to the distal end region174of the distal stent168such that the implant150is not fully covered. For example, at least a portion of the distal stent168may be a bare stent. This may allow for tissue ingrowth to further secure the implant150. In some instances, all or a portion of the proximal stent160may be bare. Alternatively, and/or additionally, one or both of the proximal stent160and the distal stent168may be covered with a material or structure different from the sleeve176to provide a partially covered implant150. The sleeve176may be secured to one or both of the stents160,168by an adhesive or other methods known in the art, including by not limited to thermal methods, mechanical methods, etc.

The sleeve176may have an elongated, tubular shape defining a lumen which may be similar in form or function to the sleeves36,42described above. The lumen of the stents160,168and the flexible sleeve176may be fluidly connected to form the lumen158of the implant150. It is contemplated that one or more of the regions152,154,156of the implant150may include more than one lumen, as desired. The sleeve176may be a thin flexible membrane that readily collapses on itself. However, in some instances, the sleeve176may be provided with a radial support.

The sleeve176may include one or more apertures182extending through a thickness of the sleeve176. For example, the sleeve176may have a mesh-like structure. The removal of material to form the apertures182may allow for a connecting element to remain between the proximal stent160and the distal stent168while increasing the deformability and/or moveability of the sleeve176. Thus, when the sleeve176is positioned across a valve or sphincter, such as, but not limited to the pyloric valve, the reduced amount of material placed across the valve region may further allow for normal valve function. The sleeve176may include any number of apertures182desired, such as, but not limited to one, two, three, ten, twenty, fifty, or more. The apertures182may be positioned uniformly about a circumference and/or length of the sleeve176(e.g., having a uniform distance between adjacent apertures182) or eccentrically about a circumference and/or length of the sleeve176(e.g., having an unequal distant between adjacent apertures182).

In one illustrative example, the implant150may be sized to be positioned within the outlet of the stomach, extend across the pylorus and into the duodenum to treat, for example, gastric outlet obstruction. In such an example, the proximal stent160may be sized to prevent implant150from migrating distally through the stomach outlet. For example, the proximal end region164of the proximal stent160may have an outer diameter184in the range of about 25 millimeters (mm) to about 50 mm. It is contemplated that the shape of the proximal stent160may be formed to match or generally conform to the shape of the stomach exit. The sleeve176may be configured to extend across the pylorus and may have a length186in the range of about 6 mm to about 15 mm. The distal stent168may be sized to be positioned within the duodenal bulb and duodenum, respectively, and may have an outer diameter188in the range of about 15 mm to about 25 mm. The distal stent168may have a length190in the range of about 60 mm to about 150 mm. This is just an example. It is contemplated that the sleeve176may be positioned across other valved or sphincter regions with the proximal and/or distal stents160,168sized and shaped for the adjacent anatomy.

Once implanted in a patient, the stents160,168may exert a radially outward force to help secure the implant150to the body lumen. The implant150may be positioned in the esophagus, the gastro-esophageal junction (GEJ) region, or at or near the pylorus with the sleeve164extending through the stomach or other portions of the gastro-intestinal system. In one example, the implant150may be positioned such that the proximal stent160is positioned at the stomach outlet with the sleeve176bridging the pylorus. The flared structure of the proximal stent160may use the stomach to anchor the implant150and act as an anti-migration mechanism for the implant150. For example, the large outer diameter184of the proximal end164of the proximal stent160may engage the stomach outlet to prevent or limit movement of the implant150. The distal stent168may be placed within the duodenal bulb and may extend into the duodenum. The sleeve176may be coupled to both the proximal stent160and the distal stent168such that a relative position of each section is fixed.

In some instances, the function of the pyloric valve may not have been impacted or degraded by the disease state which has caused the gastric outlet obstruction. In such an instance, it may be desirable to open the obstruction while still allowing for normal function of the pyloric valve. As described above, the sleeve176may be formed from a flexible material which may be made more flexible or pliable through the addition of apertures182. In other words, the sleeve176, and thus the length of the intermediate region154between the proximal stent160and the distal stent168, may be free from any structure configured to exert a radially outward force on the surrounding tissue. This may allow the pyloric valve to function in a natural manner (e.g., to open and close). The distal stent168may be positioned adjacent to the gastric outlet obstruction. The stent frame170of the distal stent168may be constructed with sufficient radial force (e.g., to exert a sufficient radially outward force) to open the obstruction caused by the disease state.

FIG.4illustrates a side view of another illustrative implant200including a plurality of regions, including, a first region202, a second region204, and a third region206. The illustrative implant200may be similar in form and function to the implant10described above. While the illustrative implant200is shown and described as having three regions202,204,206, it is contemplated the implant200may include any number of regions desired, such as, but not limited to, one, two, three, four, or more. Further, the regions202,204,206may be any combination of structures and materials desired. In some cases, the implant200may include features (e.g., anti-migration flares, fixation spikes, sutures, etc.) to prevent distal/proximal displacement and/or migration of the implant200, once the implant200is positioned and expanded in the body lumen. The implant200may include a lumen208extending from a proximal end214of the first region202to a distal end224of the third region206.

In some cases, the first region202may take the form of a stent210including an elongated tubular stent frame212defining a lumen which may be similar in form and function to the proximal stent20described above. The stent210may be entirely, substantially or partially, covered with a polymeric covering, such as a coating (not explicitly shown). The covering may be disposed on an inner surface and/or outer surface of the stent frame212, as desired. When so provided a polymeric covering may reduce or eliminate tissue ingrowth and/or reduce food impaction. The stent210may include regions of differing diameters. For example, the stent210may include a flared (e.g., enlarged relative to other portions of the stent210) proximal end region214tapering radially inward in a distal direction to a distal end region216. While not explicitly shown, the stent210may include regions of constant diameter or increasing diameters (e.g., increasing in the distal direction), if so desired. The stent frame212may be expandable between a radially collapsed delivery configuration and a radially expanded deployed configuration. The expanded configuration may secure the implant200at the desired location in a body lumen.

In some cases, the third region206may take the form of a stent218including an elongated tubular stent frame220defining a lumen which may be similar in form and function to the distal stent28described above. The stent218may be entirely, substantially or partially, covered with a polymeric covering, such as a coating (not explicitly shown). The covering may be disposed on an inner surface and/or outer surface of the stent frame220, as desired. When so provided a polymeric covering may reduce or eliminate tissue ingrowth and/or reduce food impaction. The stent218may have a uniform outer diameter from its proximal end region222to a location proximal to its distal end region224. In some instances, the distal end region224may include a flared region226(e.g., increasing in diameter or having an enlarged diameter relative to other portions of the stent218). In some embodiments, the flared region226may include a transition region228which may be abrupt or step-wise or flared or sloped, as desired to a relatively constant enlarged diameter. In other embodiments, the flared region may slope or flare along its entire length (e.g., a continuously changing outer diameter). The stent frame220may be expandable between a radially collapsed delivery configuration and a radially expanded deployed configuration. The expanded configuration may secure the implant200at the desired location in a body lumen. While not explicitly shown, in some embodiments, the distal stent218may extend distally to a distal end of the implant200.

In some cases, the second portion204may take the form of a flexible sleeve230. The sleeve230may extend between the distal end of the proximal stent210and the proximal end of the distal stent218. For example, the sleeve230may be connected, affixed, or secured to the distal end region216of the first or proximal stent210adjacent to a proximal end region232of the sleeve230. The sleeve230may also be connected, affixed, or secured adjacent or distal to the proximal end region222of the second or distal stent218adjacent to a distal end region234of the sleeve230. In some cases, the sleeve230may overlap a portion or all of the proximal stent210and/or a portion of the distal stent218. Said differently, the sleeve230may extend from the proximal end region214of the proximal stent210to the distal end region224of the distal stent218such that the implant200is fully covered. Alternatively, and/or additionally, one or both of the proximal stent210and the distal stent218may be covered with a material or structure different from the sleeve230to provide a partially covered implant200. The sleeve230may be secured to one or both of the stents210,218by an adhesive or other methods known in the art, including by not limited to thermal methods, mechanical methods, etc.

The sleeve230may have an elongated, tubular shape defining a lumen which may be similar in form or function to the sleeves36,42described above. The lumen of the stents210,218and the flexible sleeve230may be fluidly connected to form the lumen208of the implant200. It is contemplated that one or more of the regions202,204,206of the implant200may include more than one lumen, as desired. The sleeve230may be a thin flexible membrane that readily collapses on itself. However, in some instances, the sleeve230may be provided with a radial support.

In one illustrative example, the implant200may be sized to be positioned within the outlet of the stomach, extend across the pylorus and into the duodenum to treat, for example, gastric outlet obstruction. In such an example, the proximal stent210may be sized to prevent implant200from migrating distally through the stomach outlet. For example, the proximal end region214of the proximal stent210may have an outer diameter236in the range of about 25 millimeters (mm) to about 50 mm. It is contemplated that the shape of the proximal stent210may be formed to match or generally conform to the shape of the stomach exit. The sleeve230may be configured to extend across the pylorus and may have a length238in the range of about 6 mm to about 15 mm. The distal stent218may be sized to be positioned within the duodenal bulb and duodenum, respectively, and may have an outer diameter240in the range of about 15 mm to about 25 mm. The distal stent218may have a length242in the range of about 60 mm to about 200 mm. This is just an example. It is contemplated that the sleeve230may be positioned across other valved or sphincter regions with the proximal and/or distal stents210,218sized and shaped for the adjacent anatomy.

Once implanted in a patient, the stents210,218may exert a radially outward force to help secure the implant200to the body lumen. The implant200may be positioned in the esophagus, the gastro-esophageal junction (GEJ) region, or at or near the pylorus with the sleeve214extending through the stomach or other portions of the gastro-intestinal system. In one example, the implant200may be positioned such that the proximal stent210is positioned at the stomach outlet with the sleeve230bridging the pylorus. The flared structure of the proximal stent210may use the stomach to anchor the implant200and act as an anti-migration mechanism for the implant200. For example, the large outer diameter236of the proximal end214of the proximal stent210may engage the stomach outlet to prevent or limit movement of the implant200. The distal stent218may be placed within the duodenal bulb and may extend into the duodenum. The sleeve230may be coupled to both the proximal stent210and the distal stent218such that a relative position of each section is fixed.

In some instances, the function of the pyloric valve may not have been impacted or degraded by the disease state which has caused the gastric outlet obstruction. In such an instance, it may be desirable to open the obstruction while still allowing for normal function of the pyloric valve. In other words, the sleeve230, and thus the length of the intermediate region204between the proximal stent210and the distal stent218, may be free from any structure configured to exert a radially outward force on the surrounding tissue. This may allow the pyloric valve to function in a natural manner (e.g., to open and close). The distal stent218may be positioned adjacent to the gastric outlet obstruction. The stent frame220of the distal stent218may be constructed with sufficient radial force (e.g., to exert a sufficient radially outward force) to open the obstruction caused by the disease state.

FIG.5illustrates a side view of another illustrative implant250including a plurality of regions, including, a first region252, a second region254, and a third region256. The illustrative implant250may be similar in form and function to the implant10described above. While the illustrative implant250is shown and described as having three regions252,254,256, it is contemplated the implant250may include any number of regions desired, such as, but not limited to, one, two, three, four, or more. Further, the regions252,254,256may be any combination of structures and materials desired. In some cases, the implant250may include features (e.g., anti-migration flares, fixation spikes, sutures, etc.) to prevent distal/proximal displacement and/or migration of the implant250, once the implant250is positioned and expanded in the body lumen. The implant250may include a lumen258extending from a proximal end264of the first region252to a distal end224of the third region256.

In some cases, the first region252may take the form of a stent260including an elongated tubular stent frame262defining a lumen which may be similar in form and function to the proximal stent20described above. The stent260may be entirely, substantially or partially, covered with a polymeric covering, such as a coating (not explicitly shown). The covering may be disposed on an inner surface and/or outer surface of the stent frame262, as desired. When so provided a polymeric covering may reduce or eliminate tissue ingrowth and/or reduce food impaction. The stent260may include regions of differing diameters. For example, the stent260may include a flared (e.g., enlarged relative to other portions of the stent260) proximal end region264tapering radially inward in a distal direction to a distal end region266. While not explicitly shown, the stent260may include regions of constant diameter or increasing diameters (e.g., increasing in the distal direction), if so desired. The stent frame262may be expandable between a radially collapsed delivery configuration and a radially expanded deployed configuration. The expanded configuration may secure the implant250at the desired location in a body lumen.

In some cases, the third region256may take the form of a stent268including an elongated tubular stent frame270defining a lumen which may be similar in form and function to the distal stent28described above. In some embodiments, the distal stent frame270may be formed using a different technique from the proximal stent frame262. For example, the distal stent frame270may be knitted while the proximal stent frame262may be braided. This is just an example. Other combinations of stent frames may be used, as desired. The stent268may be entirely, substantially or partially, covered with a polymeric covering, such as a coating (not explicitly shown). The covering may be disposed on an inner surface and/or outer surface of the stent frame270, as desired. When so provided a polymeric covering may reduce or eliminate tissue ingrowth and/or reduce food impaction. The stent268may have a uniform outer diameter from its proximal end region272to its distal end region274. However, the stent268may include regions of differing diameters if so desired. The stent frame270may be expandable between a radially collapsed delivery configuration and a radially expanded deployed configuration. The expanded configuration may secure the implant250at the desired location in a body lumen. While not explicitly shown, in some embodiments, the distal stent268may extend distally to a distal end of the implant250.

In some cases, the second portion254may take the form of a flexible sleeve276. The sleeve276may extend between the distal end of the proximal stent260and the proximal end of the distal stent268. For example, the sleeve276may be connected, affixed, or secured to the distal end region266of the first or proximal stent260adjacent to a proximal end region278of the sleeve276. The sleeve276may also be connected, affixed, or secured adjacent or distal to the proximal end region222of the second or distal stent268adjacent to a distal end region280of the sleeve276. In some cases, the sleeve276may overlap a portion or all of the proximal stent260and/or a portion of the distal stent268. Said differently, the sleeve276may extend from the proximal end region264of the proximal stent260to the distal end region224of the distal stent268such that the implant250is fully covered. Alternatively, and/or additionally, one or both of the proximal stent260and the distal stent268may be covered with a material or structure different from the sleeve276to provide a partially covered implant250. The sleeve276may be secured to one or both of the stents260,268by an adhesive or other methods known in the art, including by not limited to thermal methods, mechanical methods, etc.

The sleeve276may have an elongated, tubular shape defining a lumen which may be similar in form or function to the sleeves36,42described above. The lumen of the stents260,268and the flexible sleeve276may be fluidly connected to form the lumen258of the implant250. It is contemplated that one or more of the regions252,254,256of the implant250may include more than one lumen, as desired. The sleeve276may be a thin flexible membrane that readily collapses on itself. However, in some instances, the sleeve276may be provided with a radial support.

In one illustrative example, the implant250may be sized to be positioned within the outlet of the stomach, extend across the pylorus and into the duodenum to treat, for example, gastric outlet obstruction. In such an example, the proximal stent260may be sized to prevent implant250from migrating distally through the stomach outlet. For example, the proximal end region264of the proximal stent260may have an outer diameter282in the range of about 25 millimeters (mm) to about 50 mm. It is contemplated that the shape of the proximal stent260may be formed to match or generally conform to the shape of the stomach exit. The sleeve276may be configured to extend across the pylorus and may have a length284in the range of about 6 mm to about 15 mm. The distal stent268may be sized to be positioned within the duodenal bulb and duodenum, respectively, and may have an outer diameter286in the range of about 15 mm to about 25 mm. The distal stent268may have a length288in the range of about 60 mm to about 250 mm. This is just an example. It is contemplated that the sleeve276may be positioned across other valved or sphincter regions with the proximal and/or distal stents260,268sized and shaped for the adjacent anatomy.

Once implanted in a patient, the stents260,268may exert a radially outward force to help secure the implant250to the body lumen. The implant250may be positioned in the esophagus, the gastro-esophageal junction (GEJ) region, or at or near the pylorus with the sleeve264extending through the stomach or other portions of the gastro-intestinal system. In one example, the implant250may be positioned such that the proximal stent260is positioned at the stomach outlet with the sleeve276bridging the pylorus. The flared structure of the proximal stent260may use the stomach to anchor the implant250and act as an anti-migration mechanism for the implant250. For example, the large outer diameter282of the proximal end264of the proximal stent260may engage the stomach outlet to prevent or limit movement of the implant250. The distal stent268may be placed within the duodenal bulb and may extend into the duodenum. The sleeve276may be coupled to both the proximal stent260and the distal stent268such that a relative position of each section is fixed.

In some instances, the function of the pyloric valve may not have been impacted or degraded by the disease state which has caused the gastric outlet obstruction. In such an instance, it may be desirable to open the obstruction while still allowing for normal function of the pyloric valve. In other words, the sleeve276, and thus the length of the intermediate region254between the proximal stent260and the distal stent268, may be free from any structure configured to exert a radially outward force on the surrounding tissue. This may allow the pyloric valve to function in a natural manner (e.g., to open and close). The distal stent268may be positioned adjacent to the gastric outlet obstruction. The stent frame270of the distal stent268may be constructed with sufficient radial force (e.g., to exert a sufficient radially outward force) to open the obstruction caused by the disease state.

FIG.6illustrates a side view of the illustrative implant10ofFIG.1including a retrieval suture60. Some implants, such as, but not limited to the implant10shown inFIG.6may be designed or intended to be removable or repositionable. In some cases, a suture, such as, but not limited to, the suture60illustrated may be used to collapse a portion of the implant (in some instances, the suture may be woven through the scaffolding adjacent a proximal end of the implant) to reduce the profile of an implant. As described above, the implant10may be positioned across a valve location (e.g., the pyloric valve) such that the proximal stent20is proximal to the valve and the distal stent28is distal to the valve. As the stent frame22of the proximal stent20is not directly coupled with the stent frame30of the distal stent28, a suture woven through the proximal end region24of the proximal stent20may not necessarily reduce the profile of both the proximal stent20and the distal stent28. It is contemplated that in order to remove or reposition the implant10both the profile of the proximal stent20and the distal stent28may need to be reduced in order to move the implant10. For example, the distal stent28may have a deployed diameter that is larger than the pyloric valve (or other natural valve) to prevent or reduce proximal migration. As such, to move the implant10a profile of the distal stent28may need to be reduced from its deployed configuration.

In order to collapse both the proximal stent20and the distal stent28, the suture60may include a plurality of components or regions each configured to perform a function. A first region of the suture60may be a retrieval suture loop62which may be configured to be grasped by forceps or another tool during a clinical procedure for stent removal or repositioning. The retrieval suture loop62may extend proximally from the proximal end region24of the proximal stent20to allow the retrieval suture loop62to be easily grasped and pulled in a proximal direction. However, this is not required. In some instances, it may be desirable to position the retrieval suture loop62near the distal stent28. It is contemplated that the suture60may be arranged in a number of different patterns such that various portions of the proximal stent20and/or the distal stent28are collapsed in a desired order. For example, in some instances, it may be desirable to collapse the proximal end region32of the distal stent28prior to collapsing the proximal stent20.

A second region of the suture60may include a first suture loop64which is interwoven to the proximal end region24of the proximal stent20. The first suture loop64may extend around the entire circumference of the proximal end region24of the proximal stent20. The first suture loop64may be configured to reduce a profile of the proximal stent20from its deployed configuration. A third region of the suture60may include a second suture loop66which is interwoven through the proximal end region32of the distal stent28. The second suture loop66may extend around the entire circumference of the proximal end region32of the distal stent28. The second suture loop66may be configured to reduce the profile of the distal stent28from its deployed configuration. A fourth region of the suture60may include a connecting suture portion68that extends between and couples the first suture loop64and the second suture loop66. The connecting suture portion68may be configured to couple the first suture loop64and the second suture loop66such that actuation of the retrieval suture loop62is translated to both the first suture loop64and the second suture loop66. It is noted that in some instances, the suture60may not include a portion, such as the retrieval suture loop62, extending proximally from the first suture loop64, and thus surgical personnel may grasp the first suture loop64directly to initiate retrieval of the implant10.

The suture60may be formed from a length of material having a first end70and a second end72. The length of material may be one long continuous unitary structure or a plurality of structures coupled together, as desired. To assemble the suture60with the implant10, the first end70may be interwoven through the stent frame22adjacent the proximal end region24of the proximal stent20until it extends about the circumference or substantially all of the circumference of the proximal stent20. In some instances the suture60may be tied, knotted or otherwise secured to itself at the juncture of the circumferential portion of the first suture loop64and the connecting suture portion68. The first end70of the suture60may then be advanced distally through or alongside the proximal stent20and the proximal sleeve36until it reaches the proximal end region32of the distal stent28, thus forming the connecting suture portion68. It is contemplated that the connecting suture portion68may extend along an outer surface of the proximal stent20and proximal sleeve36or along an inner surface (e.g., within the lumen48) of the proximal stent20and the proximal sleeve36, as desired. The first end70of the suture60may then be interwoven through the stent frame30adjacent to the proximal end region32of the distal stent28until extends about the circumference or substantially all of the circumference of the distal stent28. The first end70of the suture60may then be knotted, tied, or otherwise secured to itself or the distal stent28. The second end72of the suture60may be looped or knotted to form the retrieval suture loop62.

To collapse the implant10the retrieval suture loop62, or the first suture loop64in the absence of the retrieval suture loop62, may be pulled or otherwise actuated in a proximal direction. As the retrieval suture loop62, or the first suture loop64in the absence of the retrieval suture loop62, is pulled in the proximal direction, the first suture loop64begins to constrain or reduce the diameter of the proximal stent20as shown inFIG.7, which illustrates a side view of the illustrative implant10during suture60actuation. It is contemplated that the length of the connecting suture portion68may be predetermined and selected based on both the difference in diameter of the proximal end region24of the proximal stent and the proximal end region32of the distal stent28and the distance between the proximal end region24of the first proximal stent20and the proximal end region32of the distal stent28. The length of the connecting suture portion68may be greater than the distance between the first suture loop64and the second suture loop66in the deployed, expanded configuration, providing the connecting suture portion68slack. Thus, the length of the connecting suture portion68may be selected such that the first suture loop64is pulled to constrain the proximal end region24of the proximal stent20a first amount before the slack is taken up and the connecting suture portion68is pulled taut. Thereafter, further pulling on the retrieval suture loop62, or the first suture loop64in the absence of the retrieval suture loop62, causes the connecting suture portion68to apply a pulling force on the second suture loop66to begin constraining the distal stent28. For example, the length may be selected such that when the diameter of the proximal end region24of the proximal stent20is partially constrained or reduced in diameter a first amount, the second suture loop66begins to constrain or reduce the diameter of the distal stent28adjacent the proximal end32thereof. The length may be selected such that when the diameter of the proximal end region24of the proximal stent20is constrained or reduced to approximately the same diameter as the distal end region32of the distal stent the second suture loop66begins to constrain a reduced diameter of the distal stent28adjacent the proximal end32thereof. In other words, the connecting suture portion68may include some slack or extra length that prevents the proximal actuation of the retrieval suture loop62from actuating the second suture loop66until after the first suture loop64has been at least partially constrained. Continued proximal actuation of the retrieval suture loop62once the proximal end region24of the proximal stent20has been partially constrained (e.g., is approximately equal in diameter to the proximal end region32of the distal stent28) will cause both the proximal stent20and the distal stent28to reduce in diameter or constrain at approximately the same rate at the same time, as shown inFIG.8, which illustrates a side view of the illustrative implant10with the implant10in a fully constrained configuration. This may allow for a smooth and easy repositioning or removal. However, in some embodiments, the length of the connecting suture portion68may be selected such that the proximal end regions24,32of the proximal and distal stents20,28are configured to collapse the reducing profile at approximately the same time.FIG.9illustrates a side view of the illustrative implant10ofFIG.1including an alternative retrieval suture80. In order to collapse both the proximal stent20and the distal stent28, the suture80may include a plurality of components or regions each configured to perform a function. A first region of the suture80may be a retrieval suture loop82which may be configured to be grasped by forceps or another tool during a clinical procedure for stent removal or repositioning. A second region of the suture80may include a first suture loop84which is interwoven within the distal end region34of the distal stent28. The first suture loop84may be configured to reduce a profile of the distal stent28from its deployed configuration. A third region of the suture80may include a second suture loop86which is interwoven through the distal end region26of the proximal stent20. The second suture loop86may be configured to reduce the profile of the proximal stent20from its deployed configuration. A fourth region of the suture80may include a connecting suture portion88that extends between and couples the first suture loop84and the second suture loop86. The connecting suture portion88may be configured to couple the first suture loop84and the second suture loop86such that actuation of the retrieval suture loop82is translated to both the first suture loop84and the second suture loop86.

The suture80may be formed from a length of material having a first end90and a second end72. The length of material may be one long continuous unitary structure or a plurality of structures coupled together, as desired. To assemble the suture80with the implant10, the first end90may be interwoven through the stent frame30adjacent the distal end region34of the distal stent28until it extends about the circumference or substantially all of the circumference of the distal stent28. In some instances the suture80may be tied, knotted or otherwise secured to itself at the juncture of the circumferential portion of the first suture loop84and the connecting suture portion88. The first end90of the suture80may then be advanced proximally through the distal stent28and the proximal sleeve36until it reaches the distal end region26of the proximal stent20, thus forming the connecting suture portion88. It is contemplated that the connecting suture portion88may extend along an outer surface of the distal stent28and proximal sleeve36or along an inner surface (e.g., within the lumen48) of the distal stent28and the proximal sleeve36, as desired. The first end90of the suture80may then be interwoven through the stent frame22adjacent to the distal end region26of the proximal stent20until extends about the circumference or substantially all of the circumference of the proximal stent20. The first end90of the suture80may then be knotted, tied, or otherwise secured to itself or the proximal stent20. The second end92of the suture80may be looped or knotted to form the retrieval suture loop82.

To collapse the implant10the retrieval suture loop82may be pushed or otherwise actuated in a distal direction. It is contemplated the device may be advanced through the lumen48to execute the distal force required to actuate the retrieval suture loop82in a distal direction. As the retrieval suture loop82is pushed in the distal direction, the first suture loop84begins to constrain or reduce the diameter of the distal stent28as shown inFIG.10, which illustrates a side view of the illustrative implant10during suture80actuation. It is contemplated that the length of the connecting suture portion88may be predetermined and selected based on both the difference in diameter of the distal end region34of the distal stent28and the distal end region26of the proximal stent20and the distance between the distal end region34of the distal stent28and the distal end region26of the proximal stent20. The length of the connecting suture portion88may be greater than the distance between the first suture loop84and the second suture loop86in the deployed, expanded configuration, providing the connecting suture portion88slack. Thus, the length of the connecting suture portion88may be selected such that the first suture loop84is pulled to constrain the distal end region34of the distal stent28a first amount before the slack is taken up and the connecting suture portion88is pulled taut. Thereafter, further pulling on the retrieval suture loop82causes the connecting suture portion88to apply a pulling force on the second suture loop86to begin constraining the proximal stent20. For example, the length may be selected such that when the diameter of the distal end region34of the distal stent28is partially constrained or reduced in diameter a first amount, the second suture loop86begins to constrain or reduce the diameter of the proximal stent20adjacent the distal end26thereof. The length may be selected such that the distal stent28is reduced in profile or diameter, at least in part, prior to reducing a diameter or profile of the distal end region26of the proximal stent20. In other words, the connecting suture portion88may include some slack or extra length that prevents the distal actuation of the retrieval suture loop82from actuating the second suture loop66until after first suture loop84has been at least partially constrained. Continued distal actuation of the retrieval suture loop82after any slack in the connecting suture portion88has been consumed through distal actuation will cause both the proximal stent20and the distal stent28to reduce in diameter or constrain at approximately the same rate at the same time, as shown inFIG.11, which illustrates a side view of the illustrative implant10with the implant10in a fully constrained configuration. This may allow for a smooth and easy repositioning or removal in a distal direction. However, in some embodiments, the length of the connecting suture portion88may be selected such that the distal end regions26,34of the proximal and distal stents20,28are configured to collapse the reducing profile at approximately the same time.

While not explicitly shown, it is contemplated that the implant10may be provided with two or more sutures or suture patterns that allow the clinician to select which stent20,28(and/or region of the stent20,28) is collapsed first. For example, the implant10may include both the suture configuration60illustrated inFIGS.6-8and the suture configuration80illustrated inFIGS.9-11.

FIG.12illustrates a side view of another illustrative implant300.FIG.302illustrates a side view of another illustrative implant300, such as, but not limited to, a stent. In some instances, the stent300may be formed from an elongated tubular stent frame302. While the stent300is described as generally tubular, it is contemplated that the stent300may take any cross-sectional shape desired. The stent300may have a first, or proximal end304, a second, or distal end306, and an intermediate region308disposed between the first end304and the second end306. The stent300may include a lumen310extending from a first opening adjacent the first end304to a second opening adjacent to the second end306to allow for the passage of food, fluids, etc.

The stent300may be expandable from a first radially collapsed configuration (not explicitly shown) to a second radially expanded configuration. In some cases, the stent300may be deployed to a configuration between the collapsed configuration and a fully expanded configuration. The stent300may be structured to extend across a stricture and to apply a radially outward pressure to the stricture in a lumen to open the lumen and allow for the passage of foods, fluids, air, etc.

The stent frame302may have a woven structure, fabricated from a number of filaments. In some embodiments, the stent frames22,30may be braided with one filament. In other embodiments, the stent frame302may be braided with several filaments, as is found, for example, in the WALLFLEX®, WALLSTENT®, and POLYFLEX® stents, made and distributed by Boston Scientific Corp. In another embodiment, the stent frame302may be knitted, such as the ULTRAFLEX™ stents made by Boston Scientific Corp. In yet another embodiment, the stent frame302may be of a knotted type, such the PRECISION COLONIC™ stents made by Boston Scientific Corp. In still another embodiment, the stent frame302may be laser cut, such as the EPIC™ stents made by Boston Scientific Corp.

It is contemplated that the stent300can be made from a number of different materials such as, but not limited to, metals, metal alloys, shape memory alloys and/or polymers, as desired, enabling the stent300to be expanded into shape when accurately positioned within the body. In some instances, the material may be selected to enable the stent300to be removed with relative ease as well. For example, the stent300can be formed from alloys such as, but not limited to, Nitinol and ELGILOY®. Depending on the material selected for construction, the stent300may be self-expanding (i.e., configured to automatically radially expand when unconstrained). In some embodiments, fibers may be used to make the stent300, which may be composite fibers, for example, having an outer shell made of Nitinol having a platinum core. It is further contemplated the stent300may be formed from polymers including, but not limited to, polyethylene terephthalate (PET). In some embodiments, the stent300may be self-expanding while in other embodiments, the stent300may be expand by an expansion device (such as, but not limited to a balloon inserted within the lumen310of the stent300). As used herein the term “self-expanding” refers to the tendency of the stent to return to a preprogrammed diameter when unrestrained from an external biasing force (for example, but not limited to a delivery catheter or sheath). The stent300may include a one-way valve, such as an elastomeric slit valve or duck bill valve, positioned within the lumen310thereof to prevent retrograde flow of gastrointestinal fluids.

In some instances, in the radially expanded configuration, the stent300may include a first end region312proximate the proximal end304and a second end region314proximate the second end306. In some embodiments, the first end region312and the second end region314may include retention features or anti-migration flared regions (not explicitly shown at the second end region314) having enlarged diameters relative to the intermediate portion308. The anti-migration flared regions, which may be positioned adjacent to the first end304and the second end306of the stent300, may be configured to engage an interior portion of the walls of the esophagus, stomach or other body lumen. In some embodiments, the retention features, or flared regions may have a larger diameter than the cylindrical intermediate region308of the stent300to prevent the stent300from migrating once placed in the esophagus, stomach, or other body lumen. It is contemplated that a transition from the cross-sectional area of the intermediate region308to the retention features or flared regions may be gradual, sloped, or occur in an abrupt step-wise manner, as desired. In other embodiments, the stent300may have a uniform diameter from the proximal end304to the distal end306.

It is contemplated that the stent300can be made from a number of different materials such as, but not limited to, metals, metal alloys, shape memory alloys and/or polymers, as desired, enabling the stent300to be expanded into shape when accurately positioned within the body. In some instances, the material may be selected to enable the stent300to be removed with relative ease as well. For example, the stent300can be formed from alloys such as, but not limited to, Nitinol and ELGILOY®. Depending on the material selected for construction, the stent300may be self-expanding or require an external force to expand the stent300. In some embodiments, composite filaments may be used to make the stent300, which may include, for example, an outer shell or cladding made of Nitinol and a core formed of platinum or other radiopaque material. It is further contemplated the stent300may be formed from polymers including, but not limited to, polyethylene terephthalate (PET). In some instances, the filaments of the stent300, or portions thereof, may be bioabsorbable or biodegradable, while in other instances the filaments of the stent300, or portions thereof, may be biostable.

The implant300may be may be entirely, substantially or partially, covered with a polymeric covering, such as a coating (not explicitly shown). The covering may be disposed on an inner surface and/or outer surface of the implant300, as desired. When so provided a polymeric covering may reduce or eliminate tissue ingrowth and/or reduce food impaction.

The implant300may further include a retrieval suture320. The suture320may include a retrieval suture loop322which may be configured to be grasped by forceps or other tool during a clinical procedure for stent removal and or repositioning. The suture320may be interwoven with the stent frame302at intervals along a length of the implant300to create a plurality of suture loops324a,324b,324c,324d,324e,324f,324g(collectively,324). Each of the suture loops324may extend entirely around the circumference of the stent frame302. It is contemplated that the suture loops324may be positioned at regular or even intervals throughout the overall length of the implant300. However, in other embodiments, the suture loops324may be positioned at eccentric or uneven intervals along the length of the implant300, as desired. Adjacent suture loops324may be connected with a longitudinal length of the suture320extending therebetween. For example, adjacent suture loops324may be connected with the suture connection links326a,326b,326c,326d,326e,326f(collectively,326) such that actuation of the retrieval suture loop322is translated to each of the individual suture loops324via the longitudinally extending suture connection links326between each successive suture loop324along the length of the implant300.

To collapse the implant300, the retrieval suture loop322, or the first suture loop134ain the absence of the retrieval suture loop322, may be pulled or otherwise actuated in a proximal direction. It is contemplated that the direction of actuation (e.g., proximal or distal) required to actuate the suture320may be dependent on the direction in which the suture320is interwoven with the stent frame302. As the retrieval suture loop322, or the first suture loop134ain the absence of the retrieval suture loop322, is actuated, the suture loops324begin to constrain or reduce the diameter of the implant300, as shown inFIG.13, which illustrates a side view of the illustrative implant300during suture320actuation. In some instances, the connection links326may have a length such that the suture loops324simultaneously (or approximately simultaneously) constrain the implant300along its length. However, this is not required. In some instances, the connection links326may have a length such that the suture loops324are sequentially actuated. For example, the next sequential suture loop324may not be actuated until the slack is removed from the preceding longitudinally extending suture connection link326and the suture connection link326is drawn taut to apply a force to the next suture loop324. Continued actuation of the retrieval suture loop322may cause the implant300to be further reduced diameter, as shown atFIG.14, which illustrates a side view of the illustrative implant300with the implant300in a fully constrained configuration. It is contemplated that simultaneous constrainment of the suture loops324may reduce the delay time between the actuation of the retrieval suture loop322and movement of the implant300during repositioning or removal. This may allow the implant300to be repositioned and/or removed with minimal impact on a vessel wall.

The materials that can be used for the various components of the implants10,100,150,200,250,300(and variations, systems or components thereof disclosed herein) and the various elements thereof disclosed herein may include those commonly associated with medical devices. For simplicity purposes, the following discussion makes reference to the implants10,100,150,200,250,300(and variations, systems or components disclosed herein). However, this is not intended to limit the devices and methods described herein, as the discussion may be applied to other elements, members, components, or devices disclosed herein.

In at least some embodiments, portions or all of implants10,100,150,200,250,300may also be doped with, made of, or otherwise include a radiopaque material. Radiopaque materials are generally understood to be materials which are opaque to RF energy in the wavelength range spanning x-ray to gamma-ray (at thicknesses of <0.005″). These materials are capable of producing a relatively dark image on a fluoroscopy screen relative to the light image that non-radiopaque materials such as tissue produce. This relatively bright image aids the user of implants10,100,150,200,250,300in determining its location. Some examples of radiopaque materials can include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloy, polymer material loaded with a radiopaque filler, and the like. Additionally, other radiopaque marker bands and/or coils may also be incorporated into the design of implants10,100,150,200,250,300to achieve the same result.

In some embodiments, a degree of Magnetic Resonance Imaging (MM) compatibility is imparted into implants10,100,150,200,250,300. For example, implants10,100,150,200,250,300or portions thereof, may be made of a material that does not substantially distort the image and create substantial artifacts (i.e., gaps in the image). Certain ferromagnetic materials, for example, may not be suitable because they may create artifacts in an Mill image. The implants10,100,150,200,250,300or portions thereof, may also be made from a material that the MM machine can image. Some materials that exhibit these characteristics include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS: R30003 such as ELGILOY®, PHYNOX®, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035 such as MP35-N® and the like), nitinol, and the like, and others.

Those skilled in the art will appreciate that the different embodiments of the implant described here, their mode of operation, etc., are merely representative of the environment in which the present disclosure operates. Accordingly, a variety of alternatively shaped collaborating components may also be used as a substitutive for the purpose of engaging, steering and locating the stent at a desired target site, thus, not limiting the scope of the present disclosure. Further, the disclosed implants may be adequately stretchable, extendable, and retractable, allowing for its flexible deployment. More particularly, the configurations described here may be applicable for other medical applications as well, and accordingly, a variety of other medical devices may be used in combination with the implant. Those medical devices may include biopsy forceps, scissors, lithotripters, dilators, other cautery tools, and the like.

Further, while the implant is generally described along with an exemplary rigid and flexible region(s), a variety of other configurations and arrangements may also be contemplated and conceived as well. In addition, the operations, devices, and components, described herein may be equally applicable for other purposes where a component is required to be positioned in places where a leakage needs to be avoided or other treatments are desired. Embodiments of the present disclosure are thus applicable to medical and/or non-medical environments. Further, certain aspects of the aforementioned embodiments may be selectively used in collaboration, or removed, during practice, without departing from the scope of the disclosed embodiments.