Delivery Systems for Gastrointestinal Implants - Patent application

Abstract

The present invention relates to a delivery device (10) for introducing and / or deploying an implant (12, 107) within the gastrointestinal tract. The implant may be a bypass sleeve. The delivery device includes a shaft assembly (24) having a longitudinal axis (L) and having an atraumatic tip component (26, 102) disposed at a distal end of the shaft assembly (24).

Description

[Technical field]

[0001] The present invention relates to the field of implants for insertion into the gastrointestinal tract, and delivery systems therefor. In some non-limiting aspects, the present invention relates to a delivery system for a bypass sleeve for bypassing a portion of the intestine. [Background technology]

[0002] Various surgical techniques and implants have been proposed to treat obesity and diabetes. Surgical techniques include the creation of a gastric pocket and gastric bypass of a portion of the stomach, duodenum and jejunum. Implants such as bypass sleeves or liners for insertion into the gastrointestinal tract have been proposed to bypass the duodenum and possibly a portion of the jejunum.

[0003] Technical challenges remain with regard to delivering and deploying implants, such as bypass sleeves, within the gastrointestinal tract, particularly in the intestine. Systems have been proposed that can be introduced via the mouth and stomach. However, such systems have limitations with regard to ease of use and the distance they can access within the intestine. For example, some clinicians currently believe that the maximum accessible distance is up to about 60 cm from the pylorus. The distance is limited by practical considerations such as the size of the delivery system, friction against the intestinal tissue, and ease of navigation without the need to apply too high a pushing force to advance the delivery system. High forces can damage the intestinal tissue and potentially risk perforating the intestinal wall. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention has been devised to at least partially address and / or alleviate one or more of the above problems. [Means for solving the problem]

[0005] Broadly speaking, a first aspect of the invention provides a delivery system, also referred to as a delivery device, for introducing and deploying an implant, e.g., a bypass sleeve, within the gastrointestinal tract, e.g., extending into the duodenum and optionally at least partially into the jejunum.

[0006] The delivery system includes a shaft assembly having a longitudinal axis. An atraumatic tip component is generally disposed at the distal end of the shaft assembly. The atraumatic tip may be carried by or coupled to the distal end.

[0007] The shaft assembly may be formed by a pusher liner and / or an inner tube. The inner tube may be disposed within the pusher liner to form a pusher catheter.

[0008] The longitudinal axis of the delivery device may be understood as the direction in which the shaft assembly extends.

[0009] "Atraumatic" may typically refer to a structure that does not damage and / or distort the patient's anatomy during the implant delivery procedure. For example, a spherical shape such as a ball may reduce the risk of perforating the intestine during delivery of the intestinal sleeve.

[0010] The delivery system may be defined independently of the implant, for example the bypass sleeve, or in combination with the implant.

[0011] The delivery system may optionally include any one, or any combination of two or more, or all of the following features: (a) The delivery system may have an atraumatic tip component carried on a distal end of a shaft assembly having a longitudinal axis. The tip component may be at least partially rotatable about the axis, at least within a predetermined range of motion, e.g., at least fully rotated in either direction. The ability of the tip to rotate about the axis may, at least to some extent, aid in easily navigating the tip component within the folded and tortuous passages of the intestine. Frictional contact may be reduced by the tip component being able to rotate as it contacts folds and bends in tissue.

[0012] (b) Additionally or alternatively, the delivery system may have an atraumatic tip component carried on the distal end of the shaft assembly, the tip component defining a clamp for clamping an end (e.g., downstream end) of the sleeve structure. The end of the sleeve structure may have a peripheral edge, e.g., a peripheral edge. The clamp may be configured to clamp a first portion of the peripheral edge and leave a second portion of the peripheral edge unclamped. The first portion may be a minor portion and the second portion may be a major portion. By clamping only a portion of the peripheral edge of the sleeve structure, the amount of clamped material can be kept small, facilitating later release without compromising the clamping effect. The tip component may be smaller than a similar device that clamps all of the peripheral edge at the end of the sleeve structure. A small tip component may aid in ease of navigation through the intestine and facilitate access to deeper portions of the intestine.

[0013] As used herein, the term "sleeve structure" encompasses a sleeve in which the ends of the sleeve are at the ends of the structure and a sleeve that may be partially invaginated such that at least one of the sleeve ends is not at the end of the structure. The ends of a sleeve structure correspond to the points at which the sleeve is folded inwardly over itself.

[0014] (c) In addition to or instead of (a) and / or (b) above, the delivery system may have an atraumatic tip component coupled to the distal end of the shaft assembly by a releasable connection, e.g., an anchor. The connection may optionally be released by manipulation of the shaft assembly by a handle or actuator remote from the distal end.

[0015] In some embodiments, the shaft assembly includes, for example, first and second elongate shaft components nested within one another. The connection may be releasable by relative movement of one shaft component relative to the other. Preferably, the relative movement is non-forward movement (e.g., non-distal movement). Non-forward movement may include, for example, retraction or rotation. By avoiding forward movement, there is a significantly lower risk of the exposed shaft assembly being inadvertently advanced into exposed tissue, potentially damaging or perforating the tissue.

[0016] Various embodiments of the releasable connection are envisioned, whether or not non-forward movement of the shaft assembly is used.

[0017] One example of a releasable connection is an extendable and / or retractable gripper. The connection may be released by extending and / or retracting the gripper. In one form, the gripper can change configuration between an extended configuration and a retracted configuration. In one configuration (e.g., an extended configuration), the gripper is configured to couple the shaft assembly to the atraumatic tip component, for example, by extending within a socket of the tip component to internally grip the socket. In the other configuration (e.g., a retracted configuration), the gripper is configured to release the atraumatic tip, for example, by disengaging from within the socket of the tip component.

[0018] Another example of a releasable connection may be a magnetic connection between the first and second couplings. The magnetic connection may be formed by at least one permanent magnet, optionally a first and a second permanent magnet. The connection may be releasable by manipulating the shaft assembly to force the first and second couplings apart. For example, one coupling may be retracted into the shaft assembly to separate from the coupling on the opposite side of the atraumatic tip. In another example, an electromagnetic coupling may be used. The coupling may be released by reducing or removing the application of current to the electromagnetic coupling.

[0019] The releasable connection may comprise a phase-change element having two distinct phases. For example, the phase-change element may comprise or consist of an expandable element having an austenite phase and a martensite phase. The phase-change element may be adapted to provide a fixed connection between the shaft assembly and the atraumatic ball in a first phase (e.g., in the austenite phase) and to release the atraumatic tip component from the shaft assembly in a second phase (e.g., in the martensite phase). The martensite phase in a phase-change material is generally more mechanically flexible than the austenite phase. Thus, the expandable element may provide a fixed connection in the austenite phase, which may be released by being drawn to the martensite phase, which may be readily deformable.

[0020] In particular, the phase-change element may be formed by a shape memory alloy, such as Nitinol, where a first phase is a high temperature phase and a second phase is a low temperature phase. The shape memory alloy may be adapted such that the transition temperature, in particular the HT transition temperature at which austenite transforms to martensite, is typically below 4°C for medical device applications designed for the human body temperature environment.

[0021] (d) In addition to or instead of (a) and / or (b) and / or (c) above, the implant may comprise a bypass sleeve having an upstream end and a downstream end, the implant further comprising a downstream anchor movably coupled to the downstream end of the implant and / or the bypass sleeve by one or more tethers.

[0022] The anchor may be relatively heavy, for example having a weight of at least about 5 grams, optionally in the range of about 5 grams to about 10 grams, so that it tends to be retracted by gravity and further into the intestine. The anchor may thus bias the downstream end of the sleeve in an antegrade direction relative to the direction of flow of material in the intestinal tract. During deployment, the anchor may retract the downstream end of the sleeve further downstream, helping to deploy the sleeve further longitudinally into the intestine. This may facilitate deployment of sleeves that are, for example, longer than 60 cm, optionally at least 70 cm, optionally at least 80 cm, optionally at least 90 cm, optionally at least 100 cm. After deployment, and whatever the length of the sleeve, the anchor may resist the tendency of the downstream end of the sleeve to move in a retrograde direction, for example, if the patient vomits. Vomiting is one condition in which conventional bypass sleeves may undergo retrograde migration and are at risk of obstruction. Provision of the anchors described herein may reduce the risk of such retrograde migration.

[0023] In some embodiments, prior to deployment of the sleeve, the downstream end of the sleeve may be partially invaginated within the body of the sleeve to define a sleeve structure with a reduced length prior to deployment. The length of the invaginated portion may be, for example, approximately the same length as the tether or may be shorter than the tether. In use, after deployment, the anchor biases the downstream end in a distal (e.g., antegrade) direction, disengaging the invaginated sleeve from the invagination and returning it to its fully extended length.

[0024] The implant may be inverted onto the delivery system, particularly if the implant is attached to an anchor configured as an atraumatic tip of the delivery system. The atraumatic tip may be located at the distal end of the delivery system as described above.

[0025] The tether attaching the anchor to the sleeve may be configured to be permanent, such that the anchor remains attached to the sleeve, or may be detached when the sleeve is withdrawn from the intestine after a period of use, or the tether may be biodegradable, such that the anchor detaches from the sleeve after a period of time and passes naturally through the intestine and out of the body via the anus.

[0026] Optionally, the anchor is configured to form an atraumatic tip component of or for the delivery system. Such a configuration allows the anchor to serve a dual purpose of also having a function during introduction into the body prior to deployment of the sleeve. For example, the anchor may form a tip component having any of features (a) and / or (b) and / or (c) described above.

[0027] A second, closely related aspect of the invention is a method of separating a tip component from a shaft assembly of a delivery system, comprising the steps of: The method includes injecting a fluid through the shaft assembly to compress and separate the tip component from the shaft assembly.

[0028] Preferably, the fluid has a temperature adapted to bring the releasable connection to a low temperature phase such as to release the atraumatic tip component from the shaft assembly. For example, the fluid may be saline having a temperature of less than 4° C. Thus, injecting the fluid may cool the phase-change element from body temperature (i.e., 37° C.) to less than 4° C., thus causing a phase transition, for example, from austenite to martensite.

[0029] In some preferred embodiments, the system is assembled by introducing a pusher catheter with a snare into the sleeved implant. The snare is typically attached to the inner tube of the catheter, which is surrounded by a liner. The distal tip of the sleeve is fastened to the snare and drawn into an atraumatic ball. The distal portion of the delivery device is then placed into the sleeve and statically held together.

[0030] The system may be used to release the snare from the proximal side after reaching the designated location. The sleeve may then be removed from the delivery device and at least the inner tube and snare may be retrieved from the treatment site via the pusher catheter liner. The atraumatic ball may then remain in place or may be pushed distally by injection of pressurized saline to release the distal tip of the sleeve. Additional saline may be injected when the pusher catheter liner is retrieved.

[0031] The method may further include releasing the coupling between the tip component and the shaft assembly before, during, and / or after the step of injecting the fluid.

[0032] Although certain aspects, features and advantages have been highlighted above, this is merely to aid in the understanding of certain concepts used in the present invention, without limiting the scope of protection. Protection is claimed for any novel ideas or features described herein and / or shown in the drawings, regardless of whether emphasis is placed on them.

[0033] Non-limiting embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0034] [Figure 1] 1 is a schematic cross-sectional view illustrating a first embodiment of a delivery system for a bypass sleeve. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing the first embodiment in a partially deployed configuration. [Diagram 3] 3 is a schematic cross-sectional view similar to FIG. 2 showing the embodiment in a fully deployed configuration. [Figure 4] FIG. 1 is a schematic cross-sectional view showing a first example of a tip structure of the first embodiment in a coupled configuration. [Diagram 5] FIG. 5 is a schematic cross-sectional view similar to FIG. 4, showing the tip structure during release. [Figure 6] FIG. 1 is a schematic cross-sectional view showing a first example of a tip structure in a released configuration. [Figure 7] FIG. 11 is a schematic cross-sectional view showing a second example of the tip structure of the first embodiment in a coupled configuration. [Figure 8] FIG. 13 is a schematic perspective view showing the construction of the tip structure. [Figure 9] FIG. 11 is a schematic cross-sectional view showing a second example in a released configuration. [Figure 10] 1 is a schematic cross-sectional view showing a second embodiment of a bypass sleeve device and a portion of a delivery system. [Figure 11] 11 is a schematic cross-sectional view of the downstream end of the bypass sleeve device of FIG. 10. [Figure 12] FIG. 2 is a schematic cross-sectional view of a sleeve device of a second embodiment in a pre-deployment configuration. [Figure 13] FIG. 13 is a schematic cross-sectional view illustrating a variation of the second embodiment in a pre-deployment configuration. [Figure 14] 14 is a schematic cross-sectional view showing the sleeve device of FIG. 13 moving to a partially deployed configuration. [Figure 15] 15 is a schematic cross-sectional view showing the sleeve device of FIGS. 13 and 14 moving into a deployed configuration. FIG. [Figure 16] 1 is a schematic diagram of a cross section of a delivery device having a phase-change element that forms a releasable connection. [Figure 17] FIG. 17 is a schematic diagram of the delivery device of FIG. 16 with a bypass sleeve. [Figure 18a] FIG. 1 is a schematic diagram of a delivery device. [Figure 18b]FIG. 1 is a schematic diagram of a delivery device. [Figure 18c] FIG. 1 is a schematic diagram of a delivery device. [Figure 19] FIG. 18A-C are detailed views of the mechanism of the device of FIGS. 18a-18c. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] When referring to the drawings, the same reference numbers are used to denote the same or similar features, whether or not explicitly stated.

[0036] 1-3, a delivery system 10 is shown for introducing and deploying an implant in the form of a bypass sleeve device 12 within the gastrointestinal tract, for example within the duodenum, and optionally at least partially within the jejunum. The sleeve device 12 comprises a flexible tubular sleeve 14 having an upstream end 16 and a downstream end 18. The sleeve 14 may have a length (after deployment) of at least about 40 cm, optionally at least about 60 cm, optionally at least about 80 cm, optionally at least about 100 cm. The sleeve may have a diameter (after deployment) of about 1.5-3 cm, preferably 2 cm to about 3 cm, optionally about 2.5 cm. One or more anchors 20 may be provided near or at the upstream end 16 for engaging the pylorus of a patient. The anchors may include, for example, self-expanding stents and / or inflatable chambers.

[0037] The delivery system 10 comprises an introducer sheath 22 in which the sleeve device 12 is initially housed in a low-profile configuration prior to deployment. In the low-profile configuration, the sleeve device 12 is axially compressed and / or radially compressed, for example to a length of about 10 cm or less, optionally about 6 cm. Particularly preferably, the sleeve may be foldable in a bellows-like configuration. However, it is also possible to deliver the sleeve fully expanded. For example, the sheath 22 may have a diameter (inner and / or outer diameter) of about 1 cm to 1.5 cm in which the sleeve device 12 is radially compressed. The sleeve 14 forms a sleeve structure, and the ends 16 and 18 of the sleeve also form the ends of the sleeve structure. These ends 16 and 18 of the sleeve and the sleeve structure are referred to interchangeably.

[0038] The delivery system 10 further includes a shaft assembly 24 extending through the sheath 22 and releasably coupled (or releasably coupleable) to a tip component 26. The tip component 26 may optionally be part of the delivery system 10, or part of the sleeve device 12 (described below), or a separate component. A releasable coupling 30 includes a first coupling portion 30a carried by the shaft assembly 24 and a second coupling portion 30b carried by the tip component 26. The shaft assembly 24 includes at least first and second shafts 24a and 24b movable relative to one another by an actuator handle 28 at the proximal end of the system 10. The first shaft 24a may be nested within a tubular bore of the second shaft 24b, and a third shaft (not shown) may also be optionally provided. The handle 28 includes a slider 32 axially movable relative to a handle body 34 for manipulating the shaft assembly 24.

[0039] The tip component 26 has an atraumatic shape to facilitate sliding advancement of the delivery system 10 within the intestine. For example, the tip component 26 has an at least partially rounded distal surface. In the illustrated example, the tip component 26 is generally spheroidal. As indicated by arrow 36, at least a portion of the tip component 26 can rotate or twist about the longitudinal axis of the delivery system 10, at least within a certain rotation angle. For example, the coupling 30 may allow the entire tip component 26 to rotate relative to the shaft assembly 24 and / or the sheath 22 and / or the sleeve device 12. In other embodiments, the tip component 26 may include a rotatable outer shell around a non-rotatable inner portion. The tip component 26 may be dimensioned to approximately match the dimensions of the sheath 22 so that it can occlude the open end of the sheath 22. The tip component 26 may have a radial diameter (relative to the longitudinal axis of the system) of about 1 cm to 1.5 cm, optionally about 1.1 cm, or about 1.2 cm or about 1.3 cm or about 1.4 cm.

[0040] The tip component 26 and / or coupling 30 are configured to clamp at least a portion of the peripheral edge of the downstream end 18 of the sleeve 24, for example, at the junction between the tip component 26 and the shaft assembly 24. In the illustrated example, only a first portion 18a of the peripheral edge is clamped, and a second portion 18b is not clamped. The first portion 18a may be a small portion (e.g., <50%) of the peripheral edge, and the second portion 18b may be a large portion (e.g., >50%).

[0041] In use, the delivery system 10 is advanced into the gastrointestinal tract via a natural body orifice, such as, for example, the patient's mouth. The delivery system 10 may be advanced through the pylorus and into the intestine through the stomach until the anchor 20 is aligned with a target location, for example, the pylorus. The sheath 22 is then retracted relative to the shaft assembly 24 to allow the sleeve 14 and anchor 20 to radially expand (or be stretched) until the anchor 20 seats the upstream end 16 of the sleeve 14 at the target location.

[0042] 2, the shaft assembly 24 is then pushed (indicated by arrow 40) by the handle unit 28 to extend the sleeve 14 axially by its downstream end 18 deeper into the intestine, for example through the duodenum and at least partially through the jejunum. The atraumatic shape of the tip component 24 and / or its ability to rotate about its longitudinal axis upon contact with folds and bends in the intestinal tissue facilitates navigation into the intestine.

[0043] 3, after the sleeve 14 is extended, the tip component 26 is released from the downstream end 18 of the sleeve 18 by manipulation of the shaft assembly 24 using the handle unit 28. In this embodiment, the couplings 30a, 30b are released by retracting one shaft (e.g., 24a) relative to the other shaft (e.g., 24b). For example, the slider 32 is retracted proximally relative to the handle body 34 to retract one shaft relative to the other.

[0044] If desired, fluid (e.g., saline, as indicated by arrow 42) may be injected through at least one shaft of the shaft assembly 24 to "blow" the tip component 26 without the shaft assembly 24 and release the clamping engagement of the downstream end 18 of the sleeve 14. Fluid may continue to be injected through the shaft assembly 24 as the shaft assembly is withdrawn proximally through the sleeve 14, further stretching the sleeve 14 radially outward until it is fully deployed.

[0045] As indicated by arrow 44, the tip component 26 separates from the shaft assembly 24 and travels through the intestines along with the feces to be expelled from the gastrointestinal tract via the anus. The size and atraumatic shape of the tip component 26 facilitates natural expulsion.

[0046] 4-6 show a first example of the tip structure and coupling 30 in more detail. The coupling 30a of the shaft assembly 24 comprises an extendable and / or collapsible gripper in the form of alligator jaws 46 attached to the inner shaft of the shaft assembly 24. Axial advancement of the inner shaft relative to the surrounding tubular shaft 24b allows the jaws 46 to extend (e.g., self-extend) to an expanded configuration (FIG. 4). Axial retraction of the inner shaft compresses the jaws 46 into the surrounding shaft 24b (FIGS. 5 and 6). Although other forms of extendable and / or collapsible coupling 30a are envisioned, the alligator jaws 46 can provide a reliable mechanism that is small in size.

[0047] The coupling portion 30b of the tip component 26 includes an internal socket 48 within the tip component 26, optionally with a narrow mouth 50. The socket 48 and / or mouth 50 are sized to allow the coupling portion 30a to slide in and / or out of the socket 48 when the coupling portion 30a is in its collapsed configuration, but to lock the coupling portion 30a inside the socket 48 when the coupling portion 30a is in its extended configuration. The third tubular shaft 24c may optionally be slidable over the second shaft 24c to provide additional column strength to reinforce the second shaft 24b and to provide a tight fit at the mouth 50 of the socket 48.

[0048] In use, the alligator jaws 46 may be manipulated to grip or grasp the portion 18a of the downstream end of the sleeve 14 by collapsing the jaws 46 prior to attachment of the tip component 26, unless the sleeve 14 has been previously attached. With the jaws 46 in the collapsed configuration, the jaws are introduced into the socket 48 of the tip component 26, engaging the tip component 26 and drawing the gripped portion of the sleeve into the tip component 26. The jaws 46 are then manipulated to expand within the socket 48, thereby locking the tip component 26 to the shaft assembly 24 and clamping the portion 18a of the sleeve 14 at the junction between the tip component 26 and the shaft assembly 24. The third shaft 24c may be advanced into the mouth 50 of the socket 48 to form a tight fit, which serves to further clamp the sleeve 14 at the mouth 50. Such an arrangement clamps the sleeve 14 while allowing the tip component 26 to rotate about the axis of the shaft assembly 24.

[0049] 5 and 6, when it is desired to release the coupling 30, the alligator jaws 46 are retracted into the shaft 24b. The third shaft 24c may also be retracted from the mouth 50 of the socket 50. The tip component 26 is free to separate from the shaft assembly 24, releasing the clamped portion of the sleeve 14 (not shown in FIG. 6).

[0050] 7-9 show a second example of a tip structure and coupling 30 using magnetic attraction. The first and second coupling parts 30a and 30b comprise magnetically attractable elements. For example, both parts 30a and 30b may be implemented as magnets arranged in a mutually attracting orientation. Alternatively, one part 30a or 30b may be a magnet and the other part 30b or 30a, respectively, may be a ferromagnetic element.

[0051] The first coupling portion 30a is fixed to a distal end of the first shaft 24a of the shaft assembly 24. The first shaft 24a is movable relative to the surrounding second shaft 24 under the control of the handle unit 28. The second coupling portion 30b is fixed within an internal socket recess of the tip component 26. Referring to FIG. 8, in some examples, the tip component 26 may be made of two halves 26a and 26b that when assembled together secure the second coupling portion 30b within the tip component 26.

[0052] In use, unless the sleeve 14 has been previously attached, the downstream end portion 18a of the sleeve 14 to be clamped is positioned over the first coupling portion 30a prior to attachment of the tip component 26. The tip component 26 is then attached to the shaft assembly such that the portion 18a of the sleeve 14 is clamped between the magnetic attraction portions 30a and 30b. Such an arrangement clamps the sleeve 14 while allowing the tip component 26 to rotate about the axis of the shaft assembly 24.

[0053] 9, when it is desired to release the coupling 30, the first shaft 24a is retracted relative to the second shaft 24b. A counter force to the magnetic attraction is applied via the second shaft 24b, causing the first and second coupling portions 30a, 30b to move apart while simultaneously releasing the sleeve 14 from the clamping engagement between the coupling portions 30a, 30b. The tip component 26 is then free to separate from the shaft assembly 24, releasing the downstream end 18 of the sleeve 14 (not shown in FIG. 9).

[0054] 10-12 show a second embodiment in the form of an apparatus comprising a sleeve device 12 including a sleeve 14 and a downstream anchor 26' attached to the sleeve 14 by one or more tethers 58. The downstream anchor 26' is relatively heavy to facilitate the anchor dropping into the intestine and being retracted by intestinal movement. For example, the downstream anchor 26' may have a weight of about 1 gram to about 10 grams, optionally about 5 grams to about 10 grams, optionally about 5 grams. The anchor 26' may thus bias the downstream end 18 of the sleeve 14 in an antegrade direction relative to the direction of flow of material in the intestinal tract. During deployment, the anchor 26' may retract the downstream end 18 of the sleeve 14 further downstream, helping to further deploy the sleeve longitudinally into the intestine. This may facilitate deployment of a long sleeve, for example, greater than 60 cm, optionally at least 70 cm, optionally at least 80 cm, optionally at least 90 cm, optionally at least 100 cm. After deployment, and whatever the length of the sleeve 14, the downstream anchor 26' can resist the tendency of the downstream end 18 of the sleeve 14 to move in a retrograde direction, for example, if the patient vomits.

[0055] Tether 50 may have a length of about 10 cm to about 50 cm to allow downstream anchor 26' to space itself away from downstream end 18 of sleeve 14. Such a distance avoids downstream anchor 26' from obstructing the exit of sleeve 14 during use, and also provides some separation between anchor 26' and sleeve 12 within the intestine while still achieving a reliable fixation effect.

[0056] Anchor 26' is optionally fabricated as a molded plastic shell surrounding a heavy, e.g., metal, mass optionally shaped as a ball. Anchor 26' may be elongated (e.g., at least slightly longer than it is wide). For example, downstream anchor 26' may have a length of about 2 cm and a diameter of about 1 cm to about 1.5 cm, optionally about 1.2 cm. In this example, anchor 26' has an at least partially rounded shape and is embodied as a pear or teardrop shape.

[0057] Tether 58 may be configured to be permanent, such that anchor 26' remains attached to sleeve 14, or may be detached with sleeve 14 as sleeve 14 is withdrawn from the intestine after a period of use. Alternatively, tether 58 may be biodegradable, such that downstream anchor 26' will detach from sleeve 14 after a period of time and pass naturally through the intestine and out of the body via the anus.

[0058] 11 and 12, in addition to functioning as a downstream anchor, anchor 26' may also function as a tip component of delivery system 10, similar to the first embodiment. The delivery system includes a shaft assembly 24 carrying a coupling portion 30a for releasably coupling to a complementary coupling portion 30b carried by downstream anchor 26'. Coupling portions 30a and 30b may form a mechanical coupling, as in the first example, or a magnetic coupling, as in the second example.

[0059] When the sleeve device 12 is installed within the delivery system 10, the tether 58 is folded axially, allowing the downstream anchor 26' to approach the downstream end 18 of the sleeve 14 to clamp portion 18a of the downstream sleeve end 18 at the juncture between the downstream anchor 26' and the shaft assembly 24 ( FIG. 12 ). While the tether 58 may somewhat limit the ability of the downstream anchor 26' to have unlimited rotation, the tether provides enough slack material that rotation of the downstream anchor 26' is not limited to any practical extent.

[0060] By configuring the downstream anchor 26' to clamp the sleeve 14 and also function as a tip component attached to the shaft assembly 24, the delivery system 10 can be used in the same manner as described above to deploy and extend the sleeve 14 into the intestine. When the coupling 30 is released, the downstream anchor 26' separates from the shaft assembly 24 and is free to be drawn further into the intestine by its own weight and / or the flow of feces and / or the natural peristaltic movement of the intestinal wall tissue.

[0061] 13-15 show a variation of the second embodiment that allows for the deployment of even longer sleeves 14. For example, the sleeve may have a length of at least 80 cm, optionally about or at least about 100 cm or more. In this example, the downstream end 18 of the sleeve 14 is at least partially invaginated into the remainder of the body of the sleeve 14 to define a sleeve structure having an upstream end corresponding to the upstream end 16 of the sleeve and a downstream end 18' corresponding to the position where the sleeve 14 is folded to form a concave shape. The length of the invaginated portion may be about the same length as the tether 58, or shorter. The tether 58 accommodates the downstream end 18 of the sleeve being pressed inward.

[0062] The downstream anchor 26', which serves as the tip component of the delivery system, clamps the downstream end 18' of the sleeve structure in a manner similar to that described above. With reference to Figures 14 and 15, once released, the downstream anchor 26' moves in an antegrade direction to pull out the invaginated portion of the sleeve 14, thereby allowing the sleeve 14 to extend to its full length (Figure 15).

[0063] FIG. 16 shows a schematic cross-section of a delivery device 10. The delivery device 10 comprises a pusher catheter formed by a pusher liner 100 and an inner tube 101 disposed within the pusher liner 100. An atraumatic ball 102 is disposed at the distal end of the pusher catheter. The atraumatic ball 102 is coupled to the pusher catheters 100, 101 by a releasable connection formed here by radially stretched bands 103. Here, there are three bands 103, but it will be understood that more or less bands will work as well. The bands 103 are made of a Nitinol alloy with a phase transition temperature (Af temperature: Austenite-finish temperature) of about 20° C. Thus, at room temperature or above (e.g., at body temperature), the band 103 is mechanically rigid and secures the pusher catheter 100, 101 relative to the atraumatic ball 102 by being locked into the inner cavity 104 of the atraumatic ball 102. The cavity 104 has a diameter larger than the proximal opening 106 through which the pusher catheter 100, 101 extends. The band 103 is generally sized to fit into the cavity 104 without necessarily exerting force on the cavity walls, but such band 103 cannot fit through the proximal opening without deforming. Thus, generally, in the austenitic phase, the band 103 is prevented from being removed from the cavity 104 due to the rigidity of the band 103 in the austenitic phase. When the band 103 is cooled below its phase transition temperature of 4°C, the band 103 transitions to the martensite phase. In the martensite phase, the band can be deformed with relatively low forces. Thus, they can be withdrawn from the cavity 104 through the opening 106 without damaging the atraumatic ball or requiring excessive force. Cooling can be achieved by injection of chilled saline. The atraumatic ball 104 further has a distal opening 105 for attachment of an implant such as a bypass sleeve (not shown, see FIG. 17).

[0064] FIG. 17 shows diagrammatically the delivery device 10 of FIG. 16. For clarity, elements similar to those of FIG. 16 will not be described again. Here, an implant 107 in the form of a bypass sleeve is attached to the atraumatic ball 102. To this end, the distal part of the implant 107 is held by a snare 108 placed in the distal opening 105 of the ball 102. The implant 107 is inverted on the delivery device 10.

[0065] The inner catheter 101 includes a snare 108 to hold the sleeve tip. The sleeve 107 may thus prevent the ball 102 from slipping off as the outer catheter 100 pushes the ball 102 forward in the intestine. This mechanism thus provides an attachment where the ball 102 is held by the folded back sleeve 107 at one end and by the tip of the outer catheter 100 at the other end.

[0066] In some embodiments, the sleeve 107 may be pinched against the inner wall of the atraumatic ball by the pusher liner 101. This may provide additional fixation in combination with the snare 108 or may replace the snare 108 entirely. Additionally, the sleeve 107 may have perforations near its distal end that may also be used to fixate to the atraumatic ball 102. To this end, in some embodiments, the sleeve 107 may be pinched proximally by the catheter 101 and distally by the ball 102. The ball 102 may be held internally by a nitinol anchor, as described herein. Release of the sleeve 107 may be accomplished by pulling the nitinol anchor from the ball cavity, as described herein, to release the ball 102, free the sleeve 107, etc.

[0067] In such an embodiment, once deployment of the sleeve into the patient's intestine is competed, ice-cold saline may be injected from the proximal tip of the pusher tube 101, which reduces the temperature and therefore the stiffness of the band 103. Thus, the pusher tube 101 and attached band 103 may be pulled through the pusher liner 100.

[0068] After the pusher tube 101 and band 103 are fully retracted, hot saline may be injected through the pusher liner 100 to push the atraumatic ball 102 distally out of the sleeve 107. The atraumatic ball 102 may then pass through the intestine and exit the body via natural bowel movement. The pusher liner 100 may be gradually withdrawn while additional saline is injected to expand the sleeve 107 and ensure its patency.

[0069] FIG. 18a shows an overview of the delivery device 10, which is described in more detail in FIGS. 18b and 18c.

[0070] FIG. 18b shows a detailed view of panel B of FIG. 18a, showing the distal portion of the delivery device 10 including a capsule 201 for a gastric stent (not shown) including a stent holder 202. A sleeve pusher catheter 212, which may include a pusher tube and / or a pusher liner as described above, extends through the capsule along with an inflation tube 203. As will be appreciated, the distal portion, the distal location of the capsule 201, may be positioned as shown in FIG. 16 and FIG. 17, but is not shown here. Thus, the delivery device may be used to deliver a sleeve-like implant and, for example, a gastric stent connected thereto. Such an implant may be released by pulling the distal portion 201. For example, the distal portion 201 may be connected to an outer shaft 208 configured to pull back the distal portion 201 (see FIG. 18c).

[0071] FIG. 18c shows a detailed view of panel C of FIG. 18a, showing a handle portion for controlling parts of the delivery device 10. An inner shaft 211 extends through the handle and is fixedly connected to the handle. An outer shaft (see FIG. 19, 208) is concentrically disposed around the inner shaft 211 and is slidable relative to the inner shaft 211 and the handle. A sleeve pusher catheter 212 extends inside the inner shaft 211. Separately, an inflation tube 203 extends therethrough and opens into a separately disposed inflation port 207. The handle further includes a sliding mechanism 205, which comprises a stationary nut 206′, 206″ and a release nut 204, as described in FIG. 19 below. Rotation of the release nut 204 relative to the stationary nut 206′, 206″ slides the sliding mechanism 205 along the longitudinal direction, thereby moving the outer shaft 208 in the same direction. This moves the outer shaft 208 longitudinally.

[0072] FIG. 19 shows the functional principle of the element of FIG. 18c in more detail. The stationary nut 206′, 206″ is fixedly connected to the delivery device. The release nut 204 is rotatable about the longitudinal axis of the delivery device relative to the stationary nut 206′, 206″. The sliding mechanism 205 comprises an inner slider 205′ and an outer slider 205″ which together form the rotatable part of the sliding mechanism. The rotatable part is fixedly attached to the release nut 204 so that it rotates when the release nut 204 rotates. However, the rotatable part is arranged to be longitudinally slidable relative to the release nut. For example, a longitudinal groove with a corresponding protrusion may be used to transmit the rotational movement from the release nut 204 to the inner slider 205′ and the outer slider 205″. The inner slider 205′ has an inner thread that operatively connects with the outer thread of the inner screw 209. Thus, when the release nut 204 is rotated, the rotatable portion of the sliding mechanism 205 also rotates and moves along the inner thread 209, and therefore moves longitudinally relative to the release nut 204. The sliding mechanism 205 further comprises a fixed slider 205'' held by a groove formed by the inner and outer sliders 205', 205". Thus, rotational motion from the rotatable portion of the sliding mechanism 205 is not transferred to the fixed slider 205'". Instead, the fixed slider 205'" is held in a rotatably fixed position within the inner thread 209. The inner thread 209 has a slit through which the fixed slider 205'" extends and connects to the inner slider 205' and the outer slider 205". However, the groove that holds the fixed slider 205'" transfers translational motion of the rotatable portion of the sliding mechanism 205. The fixed slider 205'" is fixedly attached to the outer shaft 208. Thus, rotating the release nut 204 causes the outer shaft 208 to move along the longitudinal axis, but the outer shaft 208 does not rotate. Two inner bars 210 are positioned inside the inner thread to secure the inner thread to the stationary nuts 206', 206". As explained in the context of Figures 18a-c, the translational movement of the outer shaft 208 may be used to pull back the distal part 201, for example to release a gastric stent.In some embodiments, a sleeve pusher catheter (see, for example, FIG. 17) may be disposed within the outer shaft 208.

[0073] It will be appreciated that the handle shown in Figure 18c may additionally or alternatively be used to control other portions of the delivery device 10. The delivery devices shown in Figures 18a-19 may be combined with any of the embodiments described herein.

[0074] It is emphasized that the foregoing is merely illustrative of exemplary forms of the invention, and that many modifications and equivalents may be used without departing from the scope and / or principles of the invention.

Claims

1. A delivery device (10) for introducing and / or deploying an implant (12, 107), preferably a bypass sleeve, into the gastrointestinal tract, comprising a shaft assembly (24) having a longitudinal axis (L), and a non-traumatic tip component (26, 102) positioned at the distal end of the shaft assembly (24).

2. The delivery device (10) according to claim 1, wherein the non-traumatic tip component (26, 102) is supported on the distal end, and the non-traumatic tip component (26, 102) is at least partially rotatable about the longitudinal axis (L), preferably within a predetermined range of motion and particularly preferably rotating at least completely in either direction.

3. The non-traumatic tip component (26, 102) is supported on the distal end, and further defines a clamp for clamping the end of the sleeve structure, preferably a first portion (18a) of the peripheral edge, and particularly preferably for clamping such that a second portion (18b) of the peripheral edge is not clamped, according to claim 1, the delivery device (10).

4. The delivery device (10) according to claim 1, wherein the non-traumatic tip components (26, 102) are coupled to the distal end by a releasable connector (30a, 103), preferably a releasable anchor.

5. The delivery device (10) according to claim 1, wherein the shaft assembly (24) includes first and second elongated shaft components (24a, 24b), preferably the first and second elongated shaft components (24a, 24b) are nested together.

6. The delivery device (10) according to claim 5, wherein the releaseable connection portion (30a, 103) is releaseable by the relative movement of the first or second shaft component (24a, 24b) with respect to the other shaft component (24a, 24b).

7. The delivery device (10) according to claim 6, wherein the releaseable connection portion (30a, 103) is formed by an extendable and / or retractable gripper.

8. The delivery device (10) according to claim 6, wherein the detachable connection portion (30a, 103) is formed by a magnetic connection portion between the first and second coupling portions.

9. The delivery device (10) according to claim 4, wherein the releaseable connection portion (30a, 103) comprises a phase transition element having two distinct phases, the phase transition element being adapted to provide a fixed connection portion between the shaft assembly (24) and the non-traumatic ball in a first phase and to release the non-traumatic tip component (26, 102) from the shaft assembly (24) in a second phase.

10. The delivery device (10) according to claim 9, wherein the phase transition element is formed of a shape memory alloy, the first phase is a low-temperature phase, and the second phase is a high-temperature phase.

11. A system comprising a delivery device, preferably a delivery device (10) according to any one of claims 1 to 10, and an implant (12, 107), wherein the implant (12, 107) has an upstream end and a downstream end, and the implant (12, 107) further comprises a downstream anchor (26') movably coupled to the downstream end of the implant (12, 107) by at least one tether (58).

12. The system according to claim 11, wherein the implant (12, 107) comprises a bypass sleeve, the bypass sleeve having a length of at least 60 cm, preferably at least 80 cm, and particularly preferably at least 100 cm.

13. The system according to claim 11, wherein the anchor has a weight of at least 5 grams, preferably less than 10 grams.

14. The system according to claim 11, wherein the at least one tether (58) is configured to be permanently attached to the sleeve (14, 107).

15. The system according to claim 11, wherein at least one tether (58) is biodegradable.

16. The system according to claim 11, wherein the downstream end of the sleeve (14, 107) is at least partially recessed into the body of the sleeve (14, 107) so as to define a sleeve structure whose length is shortened before deployment.

17. The system according to claim 11, wherein the anchor is formed by the non-traumatic tip components (26, 102) of the delivery device (10).

18. The system according to claim 11, wherein the implants (12, 107) are attached to the anchors and inverted on the delivery device (10).

19. A method for separating the tip components from the shaft assembly (24) of a delivery system, A method comprising injecting fluid through the shaft assembly (24) in order to compress the tip component and separate it from the shaft assembly (24).

20. The method according to claim 19, wherein the fluid has a temperature adapted to bring a releasable connection (103) into a low-temperature phase that releases the non-traumatic tip components (26, 102) from the shaft assembly (24).

Images