Apparatus and method for creating an anastomosis - Patent application

Abstract

A device for forming an anastomosis between first and second body lumen wall sections, the device comprising a coil implant (10) comprising an elongated tubular member (16) made of a shape memory material, the elongated member self-expanding from an elongated contained configuration for introduction into the body to an implanted configuration in which a first portion (12) of the elongated member forms at least a first loop (20) of the coil and a second portion (14) of the elongated member forms at least a second loop (22) of the coil, the elongated member comprising at least one internal cavity, the coil implant further comprising a plurality of magnets (24) carried by the first and second portions of the elongated member, each magnet of the plurality being at least partially contained within the at least one internal cavity of the elongated member, the magnets being positioned such that the first loop is magnetically attracted to the second loop to form a magnetic compression anastomosis in tissue captured between the first and second loops. The loop may comprise a helix having a tailored compression force and / or a tailored flexibility.

Description

[Technical field]

[0001] FIELD OF THEINVENTION The present invention relates to the field of forming anastomoses between body lumens. Non-limiting aspects of the present invention relate to forming an anastomosis in the digestive system, preferably the digestive tract, of a patient and / or to forming a magnetic compression anastomosis. [Background technology]

[0002] 2. Background of the Invention An anastomosis is a surgical cross-connection between two different sections of a body lumen. The digestive tract is the luminal pathway in the body from the esophagus to the anus. Anastomoses formed anywhere along or within the digestive tract are a form of therapy used to treat digestion-related problems such as diabetes, obesity, bowel disease, and intestinal obstruction. Anastomoses can be formed by open surgical procedures, but achieving anastomoses equally effectively by minimally invasive procedures, e.g., laparoscopic, endoscopic, or luminal endoscopy, remains a significant technical challenge.

[0003] U.S. Patent No. 10,154,844 teaches an anastomosis device that includes a magnet coupled to the exterior of a wire capable of changing shape from a straight wire to a coil when introduced into the body. The coil is said to apply a compressive force to layers of tissue captured between the loops of the coil. The compressive force is augmented by an attractive force between magnets coupled to adjacent loops of the coil, forcing the coil through the tissue layers and forming the anastomosis. One end of the wire is said to be preferably provided with a connecting member such as a screw or nut for connection to a delivery device. Summary of the Invention [Problem to be solved by the invention]

[0004] It would be desirable to address some of the shortcomings of conventional staplers. [Means for solving the problem]

[0005] Summary of the Invention Aspects of the invention are defined in the claims.

[0006] Additionally or alternatively, an aspect of the invention provides an apparatus for forming an anastomosis between first and second body lumen wall sections, optionally in the digestive system, and further optionally in the digestive tract, of a patient.

[0007] The device comprises first and second elongate member portions comprising, e.g., made from, a shape memory material, the first and second elongate member portions being self-expandable from an elongated storage configuration for introduction into the body to an implanted configuration in which the first elongate member portion forms a first loop and the second elongate member portion forms a second loop, and at least one, and possibly both, of the elongate member portions comprises at least one internal cavity within the elongate member portion.

[0008] The device further comprises a plurality of magnets carried by the first and second elongate member portions, at least one, possibly some, and possibly all of the plurality of magnets being at least partially contained within at least one cavity of a respective elongate member portion, the magnets being capable of being positioned such that the first loop is magnetically attracted to the second loop to form a magnetic compression anastomosis in tissue captured between the first and second loops.

[0009] In some embodiments, the device comprises a coil implant, and the first and second elongate member portions are respective portions of an elongate member forming both portions. In some cases, the elongate member is a monolithic body.

[0010] Containing the magnet at least partially within one or more cavities of the elongate member portion can provide several advantages. For example, it can facilitate imparting a more streamlined shape to the device as compared to an externally mounted or carried magnet. The streamlined shape may have several advantages. The streamlined shape can aid in problem-free introduction of the device (e.g., coil device) from the delivery device. The streamlined shape can also aid in the expulsion of the device (e.g., coil device) from the body after the anastomosis is formed. For example, in the case of the digestive tract, the device (e.g., coil device) can separate from the intestinal wall and advance along with the feces through the intestine and through the patient's anus. The streamlined shape can reduce the risk of blockage or injury or discomfort to the patient.

[0011] Additionally or alternatively, housing the magnet at least partially within one or more cavities in the elongate member portion can provide a convenient method of mounting the magnet within the device, which can also help protect the magnet from external damage.

[0012] In some embodiments, at least two of the magnets may be at least partially contained within the same cavity of the elongate member portion. The elongate member portion may comprise a tube, and the cavity may comprise a hollow interior of the tube.

[0013] The tubular form of the elongate member or elongate member portion can provide more structural support than a wire, for example, as well as provide a hollow space for at least partially housing one or more of the magnets.

[0014] Regardless of the form of the elongate member or elongate member portion, the elongate member may include openings or windows spaced along its length.

[0015] At least some of the magnets may be disposed at and / or within at least some of the openings. The openings can, for example, accommodate magnets that do not fit completely within the interior hollow portion of the tube and / or allow magnets to be mounted in an orientation that does not fit completely within the interior hollow portion of the tube. If the elongated member is not tubular, the openings can provide a cavity for at least partially accommodating the magnets.

[0016] A closely related second aspect of the invention, optionally in combination with any of the features of the first aspect, provides an apparatus for forming an anastomosis between first and second body lumen wall sections, optionally in the digestive system, and further optionally in the digestive tract, of a patient.

[0017] In a second aspect, the device comprises first and second elongate member portions comprising, e.g., made from, a shape memory material, the first and second elongate member portions being self-expandable from an elongated storage configuration for introduction into the body to an implanted configuration in which the first elongate member portion forms a first loop and the second elongate member portion forms a second loop, at least one, and optionally both, of the elongate member portions comprises a tube.

[0018] The coil implant further comprises a plurality of magnets carried by the first and second elongate member portions, the magnets being positioned such that the first turn is magnetically attracted to the second turn to form a magnetic compression anastomosis in tissue captured between the first turn and the second turn.

[0019] In some embodiments, the device comprises a coil implant, and the first and second elongate member portions are respective portions of an elongate member forming both portions. In some cases, the elongate member is a monolithic body.

[0020] A closely related third aspect of the invention, optionally in combination with any of the features of the first and / or second aspects, provides an apparatus for forming an anastomosis between first and second body lumen wall sections, optionally in the digestive system, and further optionally in the digestive tract, of a patient.

[0021] In a third embodiment, the device comprises first and second elongate member portions comprising, for example made of, a shape memory material. The first and second elongate member portions are self-expandable from an elongated storage configuration for introduction into the body to an implanted configuration in which the first elongate member portion forms a first loop and the second elongate member portion forms a second loop. At least one of the loops comprises a first segment and a second segment, and optionally collectively defines a loop in the form of a spiral in the implanted configuration, the first segment being at least partially closer to a central axis of the spiral than the second segment. The spiral may optionally be approximately planar in a direction approximately perpendicular to the central axis of the device.

[0022] The coil implant further comprises a plurality of magnets carried by the first and second elongate member portions, the magnets being positioned such that the first loop is magnetically attracted to the second loop to form a magnetic compression anastomosis in tissue captured between the first and second loops.

[0023] In a third aspect, an apparatus includes: (i) the second segment is more flexible than the first segment in at least one direction of flexibility; and / or (ii) the second segment is configured to apply a smaller compressive force to the underlying tissue than the first segment; It is configured as follows.

[0024] In some embodiments, the second segment can be both more flexible and configured to apply a lower compressive force.

[0025] When used, the application of a smaller compressive force by the second segment allows the compressive effect on the tissue wall sections to be tailored to aid in anastomosis formation. The compressive force can be concentrated in a first tissue zone corresponding to the first segment of the loop, resulting in tissue necrosis where the anastomosis is formed. The smaller compressive force in a second tissue zone corresponding to the second segment may be radially outboard of and surround the first zone. The smaller compressive force can press the tissue wall sections together in the second zone to encourage tissue fusion as part of the healing effect, but possibly without necrosis in the second region. This can result in a radially thicker band of joined tissue around the anastomosis.

[0026] In some embodiments, both the first and second loops comprise the respective first and second segments.

[0027] Such a configuration can widen the area of ​​tissue joining with the goal of further ensuring a reliable continuous joint around the entirety of the anastomosis. The process of tissue necrosis and healing by which the anastomosis is formed is a biological process that is triggered by the compressive force. Different patients may experience different rates of tissue necrosis, healing, and tissue fusion, resulting in some variability in anastomosis formation from patient to patient. Moreover, while the biological process is expected to be uniform around the closed loop shape, in some cases variability may occur. For example, the joint may be naturally thicker in one area than another. Such biological variability may be exacerbated by a patient condition such as diabetes. Providing a second segment to press the tissue with a smaller compressive force can assist the biological process of joining the tissue with sufficient or extended radial thickness to reduce such variability and form a robust, leak-free joint.

[0028] In some embodiments, the magnet may be carried at least primarily by the first segment. In some cases, the second segment does not carry a magnet.

[0029] The flexibility of the second segment may also be configured to determine whether the device separates from the wall tissue once the anastomosis is formed, or whether the second segment can constrain and hold the device against the tissue wall. A relatively flexible second segment may be configured to not constrain and hold the device by bending or deforming to allow the device to pass through a smaller opening in the formed anastomosis. A relatively stiff second segment may be configured to resist bending, thereby constraining and holding the device.

[0030] In some embodiments, the device comprises a coil implant, and the first and second elongate member portions are respective portions of an elongate member forming both portions. In some cases, the elongate member is a monolithic body.

[0031] In any of the above embodiments, openings and / or cutouts in the elongate member or elongate member segments can enhance flexibility, which is particularly, but not exclusively, advantageous in the case of one or more elongate member segments that include a tube.

[0032] In some cases, such notches and / or openings are formed in one or more surface regions selected to enhance flexibility in a plane perpendicular to the central axis of the coil in the implanted configuration. For example, the one or more surface regions may be or include (i) a surface region of the elongate member portion that faces radially inward toward the central axis of the coil in the implanted configuration, and / or (ii) a surface region of the elongate member portion that faces radially outward away from the central axis of the coil in the implanted configuration.

[0033] At least some of the openings and / or notches, whether provided to enhance flexibility and / or to at least partially accommodate a magnet, may communicate with a hollow interior of the elongate member or portion.

[0034] In any of the above aspects, at least one, and possibly both, of the elongate member portions in the implanted configuration: a) a loop that extends at least 80%, and in some cases at least 90%, of one complete turn around the central axis of the loop; b) a loop that extends at least one complete turn around a central axis; c) a loop that extends at least 1.8, and in some cases at least 1.9, complete turns around the axis of the coil; d) a loop that extends at least two complete turns around the central axis; e) a loop that extends at least 2.5 full turns around the central axis, in some cases at least 2.8 full turns, in some cases at least 2.9 full turns, and in some cases at least 3.0 full turns; f) A loop that extends less than one complete turn around the central axis of the loop For example, the loop may include a circumferential discontinuity and / or a gap.

[0035] In some cases, at least one of the first and second elongate member portions includes a generally flat helical shape having more than one turn, and one turn, in some cases a radially innermost turn, may have a greater stiffness than another turn (or at least a partial turn) of the helix.

[0036] In addition to the advantages already mentioned above, providing the outer turn of the helix to be more flexible than the inner turn can facilitate introduction from a delivery device. The implant includes a shape memory material that self-expands into an implanted configuration. In use, the implant can be allowed to gradually self-expand from one end by the delivery device. By making the final portion of the device relatively flexible, the implant is less prone to bouncing or jumping when only a small portion of the implant remains under the control of the delivery device.

[0037] The term "loop" as used herein includes any form resembling a partial or complete shape extending around a central region. The loop may be approximately circular or non-circular. The loop may be approximately curved and / or include straight segments or sides. The loop may be a closed or non-closed loop shape. The loop may have a helical form (whether approximately circular spiral or approximately non-circular spiral, such as a straight spiral).

[0038] As used herein, the term "one turn" refers to the angular extent of a loop about a central axis of the first and / or second portion (or the entire device) in an implanted configuration, whether the loop is circular or not. A complete turn refers to an angular extent of 360°.

[0039] Additionally or alternatively, in any of the above, in any of the above aspects, the elongate member may further comprise a bridging section between the first portion and the second portion, the bridging section not carrying a magnet. The bridging section may be connected to the first and / or second portion.

[0040] In some embodiments, in the implanted configuration, the first turn is generally defined in a first plane, the second turn is generally defined in a second plane, and the bridging section extends between the first and second planes, and in some cases, the first plane is approximately perpendicular to the axis of the coil, and / or in some cases, the second plane is approximately perpendicular to the axis of the coil.

[0041] In the implanted configuration, the bridging section may be generally angled relative to the first and second portions of the elongate member.

[0042] Additionally or alternatively to any of the above, the device may further comprise a sleeve of flexible material covering the elongated member and / or magnet. The sleeve may function to at least partially hold the magnet in place. For example, the sleeve may fit tightly around the elongated member. Additionally or alternatively, the sleeve may provide a smooth surface. For example, the sleeve may be made from PTFE. Such a sleeve may be applied by heat shrinking the sleeve around the elongated member.

[0043] A further aspect of the invention provides a method of forming an anastomosis between first and second body lumen wall sections, comprising: a. providing a coil implant (10) comprising an elongated member (16) made of a shape memory material, the elongated member comprising first and second portions (12, 14), the implant further comprising a plurality of magnets (24) carried by the first and second portions of the elongated member; b. introducing the implant into a target site for anastomosis with the elongated member in an elongated containment configuration; c. self-expanding the elongated member into an implanted configuration in which a first portion (12) of the elongated member forms at least a first loop (20) of a coil and a second portion (14) of the elongated member forms at least a second loop (22) of the coil, the magnet being positioned such that the first loop is magnetically attracted to the second loop to form a magnetic compression anastomosis in tissue captured between the first and second loops; Includes.

[0044] In some embodiments, providing may include providing an elongate member in the form of a tube. Additionally or alternatively, providing may include providing a plurality of magnets such that each magnet of the plurality of magnets is at least partially contained within at least one internal cavity of the elongate member.

[0045] In any of the above aspects, at least one (and possibly both) of the first and second elongate member portions may be configured to spirally wind when transitioning from the stretched storage configuration to the implanted configuration. The action of winding means that the respective portions at least partially wind and / or curl around an axis to form respective loops in the implanted configuration. In some embodiments, the respective portions may wind from a non-looped shape (e.g., from a substantially linear stretched configuration) into a looped shape. For example, the loop may only be formed when in the deployed configuration.

[0046] Additionally or alternatively, in any of the above aspects, at least one (and possibly both) of the first and second elongate member portions may be at least partially wrapped and / or at least partially wrapped around the shaft, at least in the implanted configuration. In some embodiments, each portion may be wrapped from a non-looped shape (e.g., from a substantially linearly stretched configuration) into a looped shape. For example, a loop may only be formed when in the deployed configuration.

[0047] Additionally or alternatively, in any of the above embodiments including a bridging section, the diameters of the first elongate member portion, the second elongate member portion, and the bridging portion may be substantially the same as one another, at least in the implanted configuration, and optionally in the stowed configuration.

[0048] Additionally or alternatively, in any of the above embodiments including a bridging section, at least one (and possibly both) of the first and second elongate member portions may include a circumferential discontinuity where the respective elongate member portion bends into or bends to form the bridging section.

[0049] In any of the above embodiments, the device or components of the device may optionally be formed by three-dimensional printing.

[0050] Although certain aspects, features, and advantages have been highlighted above, protection is claimed for any novel features or ideas described herein and / or shown in the drawings, whether or not emphasis is given thereto. [Brief description of the drawings]

[0051] [Figure 1] FIG. 1 is a schematic perspective view from above of a first embodiment of an anastomotic coil implant in its implanted configuration. [Diagram 2] 2 is a schematic side view of the coil implant of FIG. 1 viewed from a first direction. [Diagram 3] 3 is a schematic side view similar to FIG. 2 but viewed from a second orthogonal direction. [Figure 4] FIG. 4 is a schematic plan view of the coil implant of FIGS. 1 to 3. [Diagram 5] 2 is a schematic perspective view similar to FIG. 1, showing a second embodiment of a coil implant in its implanted configuration. [Figure 6] FIG. 6 is a schematic perspective view similar to FIGS. 1 and 5, showing a third embodiment of a coil implant in its implanted configuration. [Figure 7] FIG. 7 is a schematic plan view of the coil implant of FIG. 6. [Figure 8] FIG. 7 is a schematic perspective view from above similar to FIGS. 1, 5 and 6, showing a fourth embodiment of a coil implant in its implanted configuration. [Figure 9] FIG. 6 is a schematic perspective view of the implant of FIG. 5 in its stowed configuration for delivery. [Figure 10] FIG. 10 is a schematic hybrid diagram combining FIGS. 5 and 9 in a single representation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0052] Detailed Description of the Preferred Embodiments Non-limiting embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which the same reference numbers are used to denote the same or equivalent features, whether or not they have been described in detail. Features of one embodiment may be combined with other features, whether or not they have been described in detail, in which:

[0053] Referring to the drawings, several embodiments of an apparatus for creating an anastomosis are shown in the form of a coil implant 10. The implant 10 may be suitable for use to create an anastomosis within the digestive system, and possibly the digestive tract, of a patient.

[0054] The coil implant 10 comprises a first elongate member portion 12 and a second elongate member portion 14 made from a shape memory material, possibly a shape memory alloy, for example, an alloy including nickel and titanium, such as NiTi (e.g., Nitinol) or NiTiCo. In the illustrated embodiment, the first elongate member portion 12 and the second elongate member portion 14 are formed as portions of the same elongate member 16, which may be a monolithic body. The elongate member 16 optionally further comprises a bridging section 18 between the first portion 12 and the second portion 14, as described below.

[0055] The coil implant 10 is self-expandable from a stored configuration to an introduction or implantation configuration for introduction into a patient's body. In the stored configuration (e.g., FIG. 9), the first portion 12 and the second portion 14 are generally stretched using a narrow delivery device or sheath (not shown) into a linear or nearly linear shape suitable for introduction. During use, the implant is released or ejected from the delivery device or sheath to assume the implantation configuration. In the implantation configuration (e.g., FIGS. 1-8), the first portion 12 elongates to form at least a first loop 20 and the second portion 14 elongates to form at least a second loop 22 that is substantially parallel and collinear with the first loop 20. At least one, and possibly both, of the first portion 12 and the second portion 14 are configured to at least partially spiral and / or coil around an axis when changing from the stored configuration to the implantation configuration.

[0056] The coil implant 10 further comprises a plurality of magnets 24 carried by the first portion 12 and the second portion 14. The magnets 24 are arranged such that the magnets on each portion 12, 14 generate a magnetic attraction between the two loops 20, 22.

[0057] In use, when the coil implant 10 is introduced across two adjacent body cavity wall sections, with one loop 20 on one side of the wall sections and the other loop 22 on the other side, sandwiching wall tissue between the loops 20 and 22, the magnetic attractive forces compress the tissue, causing necrosis and resulting in the biological formation of an anastomosis within a few weeks. The compressive force is distributed around the substantially complete loop shape by the elongated member portions 12 and 16 in contact with the tissue.

[0058] A feature of some of the embodiments described herein is that at least one, and possibly both, of portions 12 and 14 have at least one internal cavity 32, and at least some of the magnets 24 are at least partially housed within (at least one) cavity 32.

[0059] The embodiment shows the elongated member 16 in the form of a tube. The elongated member 16 is made from a tubular stock of shape memory material and heat treated to adopt an implanted configuration. The interior hollow of the tube forms at least a portion of a cavity for at least partially housing at least some of the magnets 24. Additionally or alternatively, whether the elongated member 16 is tubular or not, the elongated member 16 includes windows or openings 26 within which and / or at which at least some of the magnets 24 are disposed. The openings 26 may also form a portion of a cavity for one or more magnets 24. In the illustrated form, each opening 26 is associated with one magnet 24. Multiple openings 26 (e.g., on opposing surface regions of the elongated member) may be associated with the same magnet 24.

[0060] Various arrangements of the openings 26 for the magnets 24 are envisioned. For example, in the embodiment of Figures 1-4, the openings 26 are disposed in at least one, and indeed both, of (i) the surface region 16a of the elongated member 16 that faces radially inward toward the central axis 28 of the coil in the implanted configuration (e.g., the laterally inner surface region), and / or (ii) the surface region 16b of the elongated member 16 that faces radially outward away from the central axis 28 of the coil in the implanted configuration (e.g., the laterally outer surface region). In the embodiment of Figures 5-8, the openings 26 are disposed in one or more surface regions 16c of the elongated member 16 that face generally parallel to the central axis 28 of the coil in the implanted configuration (e.g., the upper and lower surface regions). Combinations of such orientations of the openings 26 are also envisioned.

[0061] The opening 26 may be generally in the surface of the elongated member 16, or the opening 26 may include a rim or “window frame,” for example, to allow for a generally flat or planar opening in a non-flat (e.g., rounded) surface of the elongated member 16.

[0062] 5-8, the magnet 24 may be fully contained within at least one cavity of the elongate member 16 such that the magnet 24 does not protrude substantially (or in some cases not at all) relative to the surface of the elongate member, or, alternatively, with reference to Figures 1-4, the magnet 24 may protrude slightly beyond the surface of the elongate member 16 that carries it.

[0063] By housing the magnet 24 at least partially in at least one cavity 32 of the elongated member 16, whether or not the magnet 24 has a protruding portion, the coil implant 10 can benefit from streamlining the shape or profile of the device. It can also provide a convenient method of attaching the magnet 24 to the elongated member. It can also provide at least some degree of protection for the magnet 24.

[0064] The magnet 24 may have any suitable shape, for example, one or more of the following: generally planar, polygonal, cylindrical, disk-shaped, rod-shaped, barrel-shaped (with inwardly tapered or inwardly curved ends). Figures 1-4 generally show a thin cylindrical or polygonal magnet 24. Figures 5-9 show a rod- or barrel-shaped magnet 24. A barrel-shaped magnet may, for example, be press-fit into an opening or cavity and held by, for example, an interference fit at both ends. In general, magnets 24 of any shape may be secured in place by any suitable technique, for example, an interference fit, welding, or adhesive attachment to the elongated member 16.

[0065] In some embodiments, the combination of elongated member 16 and magnet 24 may be covered by a sleeve of flexible material (not shown). The sleeve may function to at least partially hold the magnet in place within opening 26. For example, the sleeve may fit tightly around elongated member 26. Additionally or alternatively, the sleeve may provide a smooth surface. For example, the sleeve may be made from PTFE. Such a sleeve may be applied by heat shrinking the sleeve around elongated member 16.

[0066] Additionally or alternatively, a further feature used in some embodiments described herein, whether or not the magnet 24 is housed within one or more cavities of the elongated member 16, is that the elongated member 16 (or at least one of the portions 12, 14, 18) is tubular. A tube can generally provide more structural support than, for example, a wire. Such structural support can provide better control over the shape of the implant 10 in the implanted configuration, and also provides the potential for directional flexibility, as described below. Structural support is particularly, but not exclusively, advantageous when the coil device 10 includes a relatively small number of loops, for example, no more than three or two loops in one or both of the first portion 12 and the second portion 14.

[0067] In the illustrated embodiment, the elongate member 16 is made from a tubular shape memory material, possibly in the form of a hypotube. The illustrated embodiment shows a tube with a generally circular cross section, although other shapes are envisioned, such as oval or polygonal (e.g., triangular, quadrilateral, rectangular, square, etc.).

[0068] The use of a tubular elongate member 16 also allows the implant 10 to be optionally introduced to the implantation site over a guidewire (not shown). The magnet 24 may be positioned to provide a through passage for the guidewire through the elongate member 16. For example, the magnet 24 may have a bore (not shown) that is internally aligned with the internal hollow portion of the tube.

[0069] As discussed above, the illustrated embodiment of the coil implant 10 includes a bridging section 18 extending between and / or connecting the first portion 12 and the second portion 14. In use, when the coil device 10 is implanted across a tissue wall across which an anastomosis is to be formed, the bridging section 18 passes through the tissue wall. In the illustrated configuration, the first portion 12 defines at least a first loop in a first plane, the second portion 14 defines at least a second loop in a second plane, and the bridging section 18 extends from one plane to the other. The bridging section 18 is angled relative to these planes.

[0070] The bridging section 18 may be configured to extend inwardly around the loop shape in the implanted configuration. Such a configuration may avoid the bridging section 18 from significantly interfering with the circumferential shape of each loop, which exerts pressure on the tissue wall sandwiched between the loops. For example, with reference to Figs. 1-5 and 8, the bridging section 18 may form a D-shaped flat within the loop's contour. In these figures, the first portion 12 and the second portion 14 form a turn that extends in the same direction (e.g., both clockwise or both counterclockwise) around the central axis 28. With reference to further embodiments in Figs. 6 and 7, the bridging section 18 may, for example, form an S-shape that intersects with the central axis 28 and extends between the loops. In these figures, the first portion 12 and the second portion 14 form a turn that extends in opposite directions (e.g., one clockwise and the other counterclockwise) around the central axis 28.

[0071] In the illustrated embodiment, the loop shape formed by at least one, and possibly both, of the first portion 12 and the second portion 14 includes a circumferential discontinuity, e.g., each first portion 12 and / or second portion 14 bends into or to form a bridging section 18.

[0072] In the illustrated embodiment, the diameter of elongate member 16 can be substantially the same in first section 12, second section 14, and bridging section 18, at least in the implanted configuration, and possibly also in the stowed configuration.

[0073] 8 and 9, in addition to or in lieu of the opening 26 for the magnet 24, the elongate member 16 (and possibly the first portion 12 and the second portion 14) may include openings (e.g., slots) and / or notches 30 configured to enhance the flexibility of the elongate member 16. The notches and / or openings 30 may be formed, for example, by laser cutting the shape memory material of the elongate member 16.

[0074] The openings and / or notches 30 for flexibility are particularly advantageous when the elongate member 16 is tubular and / or rod-like, and therefore potentially has more structure and / or rigidity than a wire.

[0075] In some cases, flexibility enhancing notches and / or openings 30 are formed in one or more surface regions 16a, 16b selected to enhance flexibility in a plane perpendicular to the central axis of the coil in the implanted configuration. For example, the one or more surfaces may include one or more of (i) the surface region 16a of the elongate member 16 that faces radially inward toward the central axis of the coil in the implanted configuration, and / or (ii) the surface region 16b of the elongate member 16 that faces radially outward away from the central axis of the coil in the implanted configuration. The openings 16 can expand and collapse to enhance flexibility.

[0076] Such an arrangement allows one or both loops to exhibit greater flexibility in the plane of the loop, allowing the loops to conform closely to the shape and allow the magnets to align in register for optimal mutual attraction. Increased flexibility in the mutual plane of the loops also allows the coil implant to compress or expand into an elliptical shape as the implant separates from the tissue wall after anastomosis formation. This may facilitate expulsion of the implant, for example, through the anus, with less risk of blockage, injury, or discomfort to the patient.

[0077] The increased radial flexibility does not significantly compromise the stiffness of the coil's axial elongate member 16 in the implanted configuration, which can allow the loop to self-guide into the implanted configuration where it pinches the tissue wall, and the magnets 24 are brought axially close enough for the magnetic attractive forces to clamp tightly against the tissue from both sides.

[0078] In the illustrated embodiment, each portion 12, 14 generally defines a single and / or full turn of the loop. In general, however, portions 12, 14 and / or their respective loops may each generally include one or more of at least 0.8 full turns, at least 0.9 full turns, at least 1.0 full turns, at least 1.25 full turns, at least 1.5 full turns, at least 1.75 full turns, at least 1.8 full turns, at least 1.9 full turns, at least 2.0 full turns, sometimes at least 2.5 full turns, sometimes at least 2.8 full turns, sometimes at least 2.9 full turns, and sometimes at least 3.0 full turns.

[0079] More than two turns per loop, e.g., a helical configuration, are also contemplated, as shown by the dashed lines in FIG. 4, where the dashed lines indicate three complete turns in the loop. However, the more turns there are, the longer the implant 10 will be in its stored configuration. With reference to FIG. 10, the sum of the lengths of the first and second portions 12 and 14, and optionally the bridging section 18, defines the length of the stored configuration 34. For a coil implant 10 that includes only loops 20 and 22, each having only a single turn of diameter D in the implanted configuration, the length in the stored configuration may be 7-8 times the diameter D. The ability of the illustrated embodiment to provide an anastomosis formation device with relatively few turns on either side of the wall tissue allows the device to remain relatively compact and relatively short in the stored configuration.

[0080] In some embodiments, when at least one of the first portion 12 and the second portion 14 includes more than one complete turn of material of the respective loop 20, 22, each portion may have a first segment 40 and a second segment 42 (FIG. 4). The first segment 40 may be at least partially closer to the central axis of the helical shape than the second segment 42. The second segment 42 may be configured to provide increased flexibility and / or less compressive force against tissue compared to the first segment.

[0081] For example, flexibility can be increased by more frequent or larger notches 30. Increased flexibility reduces the tendency of the implant 10 to bounce or jump free from the delivery device when only a small portion of the implant 10 remains engaged by the delivery device. Increased flexibility can reduce forces that encourage separation of the implant 10 during the final stages of introduction.

[0082] Additionally or alternatively, less compressive force may be provided by using smaller and / or weaker magnets or by increasing the distance between adjacent magnets. Alternatively, the second segment 42 may not carry a magnet and instead rely solely on its connection to the first segment 40 at the inner turn of the loop to apply a compressive force to tissue.

[0083] By applying a relatively weaker compressive force around at least one outer turn of the spiral than the compressive force applied by the inner turn of the spiral, the compressive effect on the tissue wall sections can be tailored to aid in anastomosis formation. The compressive force can be concentrated in a first tissue zone corresponding to the first segment 40 of the loop, thereby resulting in tissue necrosis where the anastomosis is formed. A smaller compressive force in a second tissue zone corresponding to the second segment 42 can be radially outboard of and surround the first zone. The smaller compressive force can press the tissue wall sections together in the second zone to encourage tissue fusion as part of the healing effect, but possibly without necrosis in the second region. This can result in a radially thicker band of joined tissue around the anastomosis.

[0084] Although the illustrated embodiment shows an apparatus in the form of a coil implant, it will be appreciated that the techniques described herein may be used with other forms of devices, for example, where the first and second portions 12, 14 are constituted by separate devices (e.g., separate loop devices) on either side of the tissue wall section and are held in operative relationship solely by magnetic attraction.

[0085] It will be appreciated that the foregoing description is merely illustrative of preferred embodiments and is not limiting of the invention. Many modifications and improvements can be made within the principles of the invention.

Claims

**Claim 1** An apparatus for forming an anastomosis between first and second body lumen walls, the apparatus comprising a coil implant (10) comprising an elongate member (16) made of a shape memory material, the elongate member being in a stretched receiving configuration for introduction into the body, wherein a first portion (12) of the elongate member forms at least a first loop (20) of the coil, and a second portion (14) of the elongate member self-expands into an implant configuration in which it forms at least a second loop (22) of the coil, the elongate member comprising at least one internal cavity (26, 32), the coil implant further comprising a plurality of magnets (24) carried by the first and second portions of the elongate member, each of the plurality of magnets being at least partially received within the at least one internal cavity of the elongate member, the magnets being arranged such that the first loop is magnetically attracted to the second loop to form a magnetic compression anastomosis in tissue captured between the first and second loops. **Claim 2** The apparatus of claim 1, wherein at least two of the plurality of magnets (24) are at least partially received within the same cavity (32) of the elongate member. **Claim 3** The apparatus of claim 1, wherein the elongate member (16) comprises a tube and the cavity (32) comprises the hollow interior of the tube. **Claim 4** An apparatus for forming an anastomosis between first and second body lumen walls, the apparatus optionally being the apparatus according to claim 1, the apparatus comprising a coil implant (10) comprising an elongate member (16) made of a shape memory material, the elongate member (16) being self-expandable from a stretched accommodation configuration for introduction into the body to a deployment configuration in which a first portion (12) of the elongate member forms at least a first loop (20) of the coil and a second portion (14) of the elongate member forms at least a second loop (22) of the coil, the elongate member (16) comprising a tube, the coil implant further comprising a plurality of magnets (24) carried by the first and second portions of the elongate member, the magnets being arranged such that the first loop is magnetically attracted to the second loop to form a magnetic compression anastomosis in tissue captured between the first and second loops.

5. The apparatus according to claim 4, wherein the first and / or second portion (12, 14) of the elongate member comprises the tube.

6. The apparatus according to claim 1, wherein the elongate member comprises spaced openings (26) along its length and at least some of the magnets (24) are disposed at and / or within at least some of the openings (26).

7. The apparatus according to claim 6, wherein the opening (26) in which the magnet is disposed defines (i) a surface area (16a) of the elongate member (16) facing radially inwardly towards the central axis (28) of the coil in the deployment configuration, and / or (ii) a surface area (16b) of the elongate member (16) facing radially outwardly away from the central axis (28) of the coil in the deployment configuration, and / or (iii) a surface area (16c) of the elongate member (16) facing generally parallel to the central axis (28) of the coil in the deployment configuration.

8. The apparatus according to claim 7, wherein the elongate member (16) further comprises a plurality of notches and / or openings (30) for increasing the flexibility of the elongate member, or the plurality of notches and / or or openings (30) are provided.

9. The notch and / or opening (30) for enhancing flexibility is formed in one or more surface regions selected to enhance flexibility in a plane perpendicular to the central axis of the coil in the implanted configuration, and the one or more surface regions are (i) a surface region (16a) of the elongated member (16) facing radially inward toward the central axis (28) of the coil in the implanted configuration, and / or (ii) a surface region (16b) of the elongated member (16) facing radially outward away from the central axis (28) of the coil in the implanted configuration. The device according to claim 8.

10. At least some of the openings and / or notches (30) communicate with the hollow interior (32) of the elongated member (16). The device according to claim 6.

11. At least one of the first and second portions is, in the implanted configuration, a. at least 80%, optionally at least 90%, of a full turn around the central axis (28) of the coil, b. at least one full turn around the central axis (28) of the coil, c. at least 1.8 turns, optionally at least 1.9 turns, of a full turn around the central axis (28) of the coil The device according to claim 7, configured to provide one or more of the above.

12. At least one of the first and second portions (12, 14) includes a substantially flat spiral shape with more than one turn in the implanted configuration. The device according to claim 11.

13. An apparatus for forming an anastomosis between first and second body lumen walls, the apparatus being, in some cases, the apparatus according to claim 1, the apparatus comprising a coil implant (10) comprising an elongated member (16) made of a shape memory material, the elongated member being in a stretched accommodation configuration for introduction into the body, from which a first portion (12) of the elongated member forms a first loop (20) and a second portion (14) of the elongated member forms a second loop (22) self-expands into an implant configuration, and a plurality of magnets (24) carried by the first and second portions are arranged such that the first loop is magnetically attracted to the second loop to form a magnetic compression anastomosis in the tissue captured between the first loop and the second loop, at least one of the loops (20, 22) having a helical shape defined by a first segment and a second segment of the respective portion, the first segment being at least partially closer to the central axis of the helix than the second segment, the apparatus being (i) the second segment is more flexible than the first segment in at least one flexible direction, and / or (ii) the second segment is configured to apply a lower compressive force to the tissue below than the first segment is configured as apparatus.

14. The apparatus according to claim 13, wherein the first segment carries at least one magnet (24) and the second segment has no magnets.

15. The apparatus according to claim 13, wherein one turn, in some cases the innermost turn in the radial direction, has a greater rigidity than another turn in the helix.

16. The apparatus according to claim 1, wherein the elongated member (16) is a monolithic body.

17. The apparatus according to claim 1, wherein at least one of the first and second portions (12, 14) is configured to at least partially spiral around the axis when transitioning from the accommodation configuration to the implant configuration.

18. The apparatus according to claim 1, wherein at least one of the first and second portions (12, 14) is configured to at least partially wrap around the axis when transitioning from the accommodation configuration to the implant configuration.

19. The elongated member (16) further comprises a cross-linking section (18) between the first portion (12) and the second portion (14), the cross-linking section (18) not carrying a magnet, and optionally the cross-linking section (18) being connected to the first portion (12) and / or the second portion (14). The device according to any one of claims 1 to 18.

20. In the implantation configuration, the first loop (20) is generally defined in a first plane, the second loop (22) is generally defined in a second plane, the cross-linking section (18) extends between the first plane and the second plane, and optionally, the first plane is substantially perpendicular to the axis of the coil, and / or optionally, the second plane is substantially perpendicular to the axis of the coil. The device according to claim 19.

21. In the implantation configuration, the cross-linking section (18) is substantially inclined with respect to the first and second portions (12, 14) of the elongated member. The device according to claim 19.

22. The cross-linking section (18) is generally connected to the first and second portions (12, 14) of the elongated member. The device according to claim 19.

23. The diameter of the elongated member is substantially the same within at least the first and second portions (12, 14) and the cross-linking section (18) in the implantation configuration. The device according to claim 19.

24. At least one of the first and second portions (12, 14) comprises a circumferential discontinuity where the respective portion is bent to form the cross-linking section (18). The device according to claim 19.

25. A method of forming an anastomosis between first and second body lumen wall sections, a. providing a coil implant (10) comprising an elongated member (16) made of a shape memory material, the elongated member comprising first and second portions (12, 14), the coil implant (10) further comprising a plurality of magnets (24) carried by the first and second portions of the elongated member, each magnet of the plurality of magnets being at least partially received within at least one internal cavity of the elongated member. b. introducing the implant into a target site for anastomosis with the elongated member in an extended accommodation configuration; c. self - expanding the elongated member into a deployment configuration in which the first portion (12) of the elongated member forms at least a first loop (20) of the coil and the second portion (14) of the elongated member forms at least a second loop (22) of the coil, the magnets being arranged such that the first loop is magnetically attracted to the second loop to form a magnetic compression anastomosis in tissue captured between the first and second loops; A method comprising the above.

26. A method of forming an anastomosis between first and second body lumen wall sections, comprising: a. providing a coil implant (10) comprising an elongated member (16) made of a shape - memory material, the elongated member comprising a tube including first and second portions (12, 14), the implant further comprising a plurality of magnets (24) carried by the first and second portions of the elongated member; b. introducing the implant into a target site for anastomosis with the elongated member in an extended accommodation configuration; c. self - expanding the elongated member into a deployment configuration in which the first portion (12) of the elongated member forms at least a first loop (20) of the coil and the second portion (14) of the elongated member forms at least a second loop (22) of the coil, the magnets being arranged such that the first loop is magnetically attracted to the second loop to form a magnetic compression anastomosis in tissue captured between the first and second loops; A method comprising the above.

27. The method according to claim 25 or 26, wherein the self - expanding comprises at least partially winding at least one of the first and second portions circumferentially around an axis into the loop shape.

28. The method according to claim 27, wherein the self - expanding comprises at least partially winding the first portion and the second portion circumferentially around their respective axes into the loop shape.

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