Gastrointestinal tubes and their fixation

Abstract

An anchor (20) for securing a tube (10) relative to a patient's pylorus. The tube (10) may be a bypass tube or bypass conduit for bypassing a portion of the intestine. The anchor (20) may include a gastric bulb (22) that is collapsible for introduction and optionally self-expands to an operative state. The bulb (22) may have an open configuration of the low pressure chamber. The bulb (22) may be configured to partially collapse in response to stomach contractions, allowing the bulb to follow and accommodate stomach contractions. Other embodiments of the tube, anchor, balloon, and staple are also described.

Description

[Technical field]

[0001] The present invention relates to the field of tubes for insertion into the gastrointestinal tract and anchors therefor. In some non-limiting aspects, the tube is a bypass tube for bypassing a portion of the intestine.

[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. Bypass tubes or liners have been proposed for insertion into the gastrointestinal tract to bypass the duodenum and possibly a portion of the jejunum.

[0003] Technical challenges remain for many of these techniques. For example, endoscopic placement and fixation of the bypass tube remains difficult. One technique that has been proposed is to fixate the tube in the vicinity of the pylorus. However, the stomach and intestines undergo significant movement in normal bodily functions. Muscle contractions of the stomach, including the pyloric antrum, complicate maintaining the tube in place. Muscle contractions can be extreme, for example, in the event of the patient vomiting. Dislodgement either toward the duodenum or into the stomach may require medical intervention to correct the position or to retrieve the bypass tube. Many existing proposals are undermined by the apparently conflicting need for secure fixation but with atraumatic engagement with body tissue to avoid the device causing tissue irritation.

[0004] It would be desirable to address and / or alleviate one or more of the above problems. Aspects of the invention are defined in the claims.

[0005] A first aspect of the present disclosure provides an anchor for securing a tube to a patient's pylorus. The tube may be a bypass tube or a bypass conduit for bypassing a portion of the intestine. The anchor may be defined independently of the tube or in combination with the tube.

[0006] The anchor may comprise a gastric bulb coupled or coupleable to the proximal end of the tube. The gastric bulb may be expandable from a collapsed state for introduction into the stomach to an operative state within the stomach.

[0007] In some embodiments, the bulb may be configured such that in the expanded state, the pressure within the bulb is (i) below atmospheric pressure, and / or (ii) below ambient pressure within the stomach, such that the bulb is permanently substantially unpressurized compared to ambient atmospheric pressure within the stomach.

[0008] The gastric bulb may be configured to partially collapse in response to stomach contractions, allowing the bulb to follow and accommodate stomach contractions without applying significant pulling forces to the tube that could otherwise dislodge the tube.

[0009] In some embodiments, the gastric ball is self-expandable from the collapsed state to the operative state. The gastric ball may comprise a self-expanding structure, optionally a frame structure (e.g., having ribs and / or struts), and / or a mesh structure.

[0010] The gastric bulb may be open and / or have a communicating opening that allows chyme to enter the interior of the bulb. For example, the bulb may comprise an open frame or mesh.

[0011] In addition to or instead of being self-expanding, the bulb may comprise a fluid-tight chamber. The chamber may have an inlet port that may allow (i) to allow a fluid (e.g., a liquid such as saline or a gas such as air) to be drawn into the chamber when the gastric bulb expands to its operative state (e.g., in embodiments where the pressure within the bulb is intended to be subatmospheric and / or subambient pressure within the stomach) and / or (ii) to allow a fluid (e.g., a liquid such as saline or a gas such as air) to flow into the chamber to inflate the gastric bulb (e.g., in embodiments using a pressurized balloon). The chamber may be fluid-tight to the type of fluid with which it is configured to be used, e.g., it may be substantially liquid-tight to liquid fluids and substantially air-tight to gas fluids.

[0012] In some embodiments including both a self-expanding structure and a fluid-tight chamber (optionally with an inlet port), the self-expanding structure and the fluid-tight chamber may be at least partially (optionally substantially completely) nested one within the other. For example, the fluid-tight chamber may be at least partially (optionally substantially completely) nested within the self-expanding structure. The self-expanding structure may urge (e.g., pull) one or more walls of the fluid-tight chamber generally outwardly due to self-expansion of a peripheral portion of the self-expanding structure. At least one wall of the fluid-tight chamber may be attached to and / or laminated with the self-expanding structure.

[0013] Additionally or alternatively to any of the above, the gastric ball may be spaced apart from the proximal end of the tube. Optionally, the gastric ball is physically connected to the tube by one or more struts or flexible tethers. Alternatively, the gastric ball is magnetically attracted or repelled by the tube such that there is a magnetic coupling or interaction between the gastric ball and the proximal end of the tube.

[0014] The bulb may have any desired shape in the operative state, e.g., generally spherical, teardrop-shaped, diamond-shaped, rugby ball-shaped, bell-shaped (or tulip-shaped), etc. Thus, the term "bulb" encompasses any suitable, e.g., at least partially rounded, shape and size that is capable of performing an anchoring function to resist migration of the anchor from the stomach through the pylorus.

[0015] Whatever shape of bulb is used, the bulb may include a passageway, e.g., a central hole, configured to allow chyme to pass through the bulb, e.g., to exit the stomach through the pylorus.

[0016] Additionally or alternatively to any of the above, in a second aspect, the anchor can include at least one elastic element expandable from a collapsed state for introduction into the stomach and an expanded operating state in which the elastic element has an at least partially helical shape.

[0017] The elastic member may optionally define a helical shape that radially expands gradually away from the proximal end of the tube. The helical shape may include open spaces between adjacent turns or turns of the helix.

[0018] Such a configuration may be advantageous to easily collapse for introduction while at the same time expanding to a relatively large size in its operating state.

[0019] Additionally or alternatively to any of the above, a third aspect of the present disclosure provides an anchor for securing a tube relative to a patient's pylorus, the anchor comprising a first ring for engaging a stomach side of the pyloric sphincter and a second ring for engaging a duodenal side of the pyloric sphincter, the first and second rings being coupled to one another to clamp the pyloric sphincter between the rings, the first and second rings optionally having different inner and / or outer diameters from one another such that one ring has an inner diameter larger than the outer diameter of the other ring.

[0020] Such anchors can be firmly, yet atraumatically, attached to the pyloric sphincter and provide good fixation even in the presence of strong gastric contractions.

[0021] The first and / or second rings can be collapsible into a collapsed state for introduction into the pylorus. The anchor further comprises connecting elements between the rings and coupled to the rings for selectively approximating the rings to one another to clamp the pyloric sphincter, the connecting elements optionally being sutures.

[0022] In some embodiments, the anchor further comprises at least one inner ring for surrounding an inner periphery of the pyloric sphincter, optionally, the at least one inner ring comprises a first and a second inner ring.

[0023] The first and / or second rings may be made of or may include any suitable material, for example one or more of a metal, and / or a shape memory alloy, optionally Nitinol, and / or a plastic.

[0024] In addition to or in lieu of any of the above, a fourth aspect of the present disclosure provides a tube for insertion into at least the duodenum of a patient and at least one gastric bulb for inducing satiety via contact with the stomach wall. Various techniques are envisioned for configuring the bulb to contact the stomach wall, such as, for example, one or any combination of the following:

[0025] The bulb can optionally be inflated, for example with air or gas, to cause the bulb to float in the stomach.

[0026] -Multiple bulbs may be provided to at least partially fill the stomach while allowing normal stomach movements and contractions.

[0027] The bulb may be repelled from the tube in a direction towards the stomach wall, for example by magnetic repulsion.

[0028] Additionally or alternatively to any of the above, a fifth aspect of the present disclosure provides a tube for introduction into a patient's gastrointestinal tract, which is optionally a modified tract (e.g., following bypass surgery to modify the digestive pathway). The tube may be configured for introduction at the time of anastomosis.

[0029] The tube is configured to permit passage of stomach and / or intestinal contents in a first direction and to prevent passage of stomach and / or intestinal contents in an opposite, second direction.

[0030] For example, the tube may include at least one, and optionally multiple, valve elements configured to permit passage of gastric and / or intestinal contents in a first direction and impede passage of gastric and / or intestinal contents in a second direction. The valve elements may comprise flaps that open to permit passage of gastric and / or intestinal contents in the first direction through the tube and close to impede passage of gastric and / or intestinal contents in the second direction.

[0031] Such tubes can be advantageous in preventing reflux of digestive fluids into the stomach and / or esophagus. For example, the tubes can prevent digestive fluids from the pancreas from passing through the anastomosis against the normal flow direction. This can reduce discomfort that a patient may experience after surgery.

[0032] In addition to or in lieu of any of the above, a sixth aspect of the disclosure provides a tube for introduction into a patient's duodenum, the tube being made of plastic and comprising a suture-permeable and / or staple-permeable layer of woven or nonwoven fabric near or at the proximal end. The fabric allows fixation of the tube by suturing or stapling through the fabric to body tissue near or at the pylorus. The fabric may be laminated or incorporated into the plastic of the tube. The fabric helps prevent propagation of tears that would otherwise occur in the plastic material, especially when exposed to stomach movements and contractions.

[0033] In addition to or in place of any of the above, a seventh aspect of the disclosure provides a tube for introduction into the gastrointestinal tract of a patient, the outer surface of the tube being provided with an open channel extending at least partially axially and / or longitudinally relative to the tube. The channel allows gastric secretions, e.g. pancreatic juices, to migrate to the outside of the tube, avoiding the secretions being trapped by contact between the tube and the intestinal wall. Optionally, the channel may have a helical shape around the outside of the tube. Alternatively, the channel may be a longitudinal groove. Multiple channels may be provided.

[0034] In addition to or in lieu of any of the above, an eighth aspect of the present disclosure provides techniques for treating diabetes or obesity by reducing the natural volume of the stomach by creating one or more pleats (or artificial folds) in the stomach wall using at least one tissue penetrating fastener.

[0035] As used herein, the term "tissue penetrating fastener" includes any fastener that penetrates, optionally completely penetrates, tissue and includes (at least) a suture, staple, or tag pin. Tissue penetrating fasteners can be placed, for example, by endoscopic or laparoscopic techniques.

[0036] The one or more pleats may generally extend in a direction from (i) the upper to the lower part of the stomach, and / or (ii) from the esophagus to the pylorus. Such pleats may form a generally sleeve-shaped cavity or passageway within the stomach.

[0037] The eighth embodiment may optionally be used in conjunction with a bypass tube and / or anastomosis to increase the effectiveness of such devices by effectively reducing the volume of the stomach. For example, the eighth embodiment may be used in conjunction with any of the other devices described herein, among others.

[0038] In addition to or in place of any of the above, a ninth aspect of the invention provides a tissue penetrating fastener that may be used to attach one or more rings to anatomical tissue, such as pyloric sphincter tissue. The fastener comprises end pieces in the form of a head and a foot, the end pieces being interconnected by a connecting element. At least the head, and optionally the foot, can be in a generally undeployed configuration in which the head (and optionally the foot) extends alongside the connecting element for streamlined introduction. In the deployed configuration, the head (and optionally the foot) move to project laterally on either side of the connecting member.

[0039] The end piece may be made of any suitable material. The end piece may have a tubular or non-tubular form. The tubular form allows for the fastener to be introduced onto the needle, for example in its undeployed configuration. In some embodiments, the head and / or foot of the fastener are made of a shape memory alloy, for example Nitinol.

[0040] The connecting elements may be generally flexible (e.g., as a suture) or generally inflexible, such as a rigid wire, hi some embodiments, the connecting elements are formed as springs that are stretchable but biased to draw the end pieces at least partially toward one another.

[0041] In addition to or in place of any of the above aspects, a tenth aspect of the present invention provides an apparatus for securing a device to a pylorus of a patient, the apparatus comprising: at least a first ring for attachment to the pyloric sphincter, the first ring having a self-supporting shape; a plurality of tissue penetrating fasteners that can be inserted into and / or penetrate the ring for attaching the ring to the surface of the pyloric sphincter; Equipped with.

[0042] The use of a self-supporting ring allows for secure attachment to the tissue of the pyloric sphincter without the risk of attachment creep due to regeneration of intestinal tissue, which may cause the attachment location to shift over time. The ring can stabilize the attachment point even as the tissue regenerates. Gastrointestinal tissue has a rapid rate of repair and regeneration.

[0043] The tissue penetrating fastener may optionally comprise a fastener according to the ninth aspect of the present invention. The device may further comprise a second self-supporting ring for placement on and anchoring to an opposing side of the pyloric sphincter from the first ring, thereby clamping the pyloric sphincter. The anchor may be configured to pass through both rings.

[0044] In addition to or in place of any of the above aspects, an eleventh aspect of the invention provides an apparatus for attaching a device to body tissue at a patient's pylorus, the apparatus comprising a first plurality of elongate supports for removably attaching to a ring-shaped portion of the device, and a second plurality of elongate supports including penetrating elements for deploying tissue-penetrating fasteners in the ring-shaped portion of the device.

[0045] The eleventh aspect is particularly, but not exclusively, suitable for use in conjunction with the ninth and / or tenth aspects above.

[0046] Each of the second plurality of elongate supports is axially movable relative to the first plurality of elongate supports. Each of the second plurality of supports may be axially movable individually or collectively with one or more other supports of the second plurality of supports. Each of the second plurality of elongate supports may be movable between an extended position in which the second elongate support has an extent substantially the same as (optionally beyond) a level reached by the first plurality of elongate supports, and a retracted position in which the second elongate support is retracted relative to a level reached by the first plurality of elongate supports.

[0047] The penetrating elements of each second elongate support may, for example, comprise a sharp pointed needle (optionally a sharp pointed hypotube needle) around which the tissue penetrating fastener can be carried for deployment.

[0048] The device may further include a multi-lumen catheter shaft having multiple lumens for the first and second pluralities of elongate supports. The first and second pluralities of elongate supports may be circumferentially alternatingly disposed about the catheter shaft.

[0049] The device may further include a constraining sheath slidable over the catheter shaft, the constraining sheath constraining the first and second pluralities of elongate supports in a radially compressed configuration and allowing the elongate support elements to move outwardly from one another, e.g., move away or spread outward, when the constraining sheath is retracted.

[0050] In addition to or in place of any of the above aspects, a twelfth aspect of the invention includes a method of attaching a device including a ring to a pylorus of a patient, the method comprising: (a) advancing an instrument to the pylorus, the instrument including first and second pluralities of elongate supports, a ring attached to the first pluralities of supports, and the second pluralities of elongate supports including piercing elements and carrying fasteners for fastening to tissue; (b) positioning the ring adjacent a first side of the pyloric sphincter and a second elongated support adjacent a second opposite side of the pyloric sphincter; (c) advancing each second elongate support individually or collectively such that the piercing elements penetrate the pyloric sphincter and into the first side ring; (d) partially withdrawing each second elongate support individually or collectively such that a first end piece of the fastener secures the ring on the first side of the pyloric sphincter; (e) withdrawing each second elongate support individually or collectively such that a second end piece of the fastener is secured to a second side of the pyloric sphincter; Includes.

[0051] Steps (c)-(e) may be performed sequentially on one elongate support at a time, or each of steps (c)-(e) may be completed on multiple second elongate supports before proceeding to the next step.

[0052] The method of the twelfth aspect may optionally use the apparatus of the eleventh aspect above, and / or may optionally use the apparatus of the ninth and / or tenth aspects above.

[0053] In all of the above aspects, the tube may be a bypass tube or bypass conduit for bypassing a portion of the intestine.

[0054] Non-limiting embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0055] [Figure 1] FIG. 1 is a schematic side view of a first example of a gastric anchor for a duodenal tube. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing the implanted state of Example 1. [Diagram 3] FIG. 2 is a schematic side view of a second example of a gastric anchor similar to FIG. 1. [Figure 4] FIG. 13 is a schematic cross-sectional view of a further example similar to the first and second examples shown in an implanted state. [Diagram 5] FIG. 13 is a schematic cross-sectional view of a further example having at least one balloon in an implanted state. [Figure 6] FIG. 13 is a schematic cross-sectional view of a further example having at least one balloon in an implanted state. [Figure 7] FIG. 13 is a schematic cross-sectional view of a further example having multiple balloons in an implanted state. [Figure 8] 13A-13C are schematic cross-sectional views showing further examples of anchors for fixing to the pylorus. [Figure 9] FIG. 9 is a schematic cross-sectional view showing a detail of FIG. 8. [Figure 10]FIG. 10 is a schematic cross-sectional view showing a further example of an anchor similar to those of FIGS. 8 and 9. [Figure 11] 13A-13C are schematic side views of further examples of tubes that can be attached by sutures and / or staples. [Figure 12a] 11A-11C are schematic cross-sectional views showing the step of attaching a tube to the stomach wall using a pledget. [Figure 12b] 11A-11C are schematic cross-sectional views showing the step of attaching a tube to the stomach wall using a pledget. [Figure 12c] 11A-11C are schematic cross-sectional views showing the step of attaching a tube to the stomach wall using a pledget. [Figure 12d] 11A-11C are schematic cross-sectional views showing the step of attaching a tube to the stomach wall using a pledget. [Figure 13a] FIG. 13 is a schematic perspective view of the outer profile of a tube in a further example. [Figure 13b] FIG. 13 is a schematic perspective view of the outer profile of a tube in a further example. [Figure 14] FIG. 1 is a schematic diagram of a tube placed in a gastrojejunostomy. [Figure 15] FIG. 15 is a schematic cross-sectional view of the tube of FIG. 14 separated. [Figure 16] 1 is a schematic cross-sectional view showing the formation of pleats to reduce stomach volume. [Figure 17] FIG. 17 is a schematic cross-sectional view showing a detail of FIG. 16. [Figure 18] 1 is a schematic cross-sectional view showing gastric pleats in combination with other treatment devices for diverting the flow of stomach contents. FIG. [Figure 19] FIG. 1 is a schematic side view of an example of a tissue penetrating fastener. [Figure 20] FIG. 13 is a schematic side view of a second example of a tissue penetrating fastener. [Figure 21] FIG. 13 is a schematic side view of a needle carrying a tissue penetrating fastener for deployment. [Figure 22] FIG. 22 is a schematic cross-sectional view of the needle of FIG. 21. [Diagram 23]21 is a schematic side cross-sectional view of the working end of an apparatus for attaching a duodenal tube to the pyloric sphincter using the tissue penetrating fastener of FIG. 19 or FIG. 20. [Figure 24] FIG. 24 is a schematic perspective view of the working end of the instrument of FIG. 23. [Diagram 25] 25A-25C are schematic side views showing a sequence for placing a bypass tube in the duodenum using the instrumentation of FIGS. 23 and 24. [Figure 26] 25A-25C are schematic side views showing a sequence for placing a bypass tube in the duodenum using the instrumentation of FIGS. 23 and 24. [Figure 27] 25A-25C are schematic side views showing a sequence for placing a bypass tube in the duodenum using the instrumentation of FIGS. 23 and 24. [Figure 28] 25A-25C are schematic side views showing a sequence for placing a bypass tube in the duodenum using the instrumentation of FIGS. 23 and 24. [Figure 29] 25A-25C are schematic side views showing a sequence for placing a bypass tube in the duodenum using the instrumentation of FIGS. 23 and 24. [Diagram 30] 25A-25C are schematic side views showing a sequence for placing a bypass tube in the duodenum using the instrumentation of FIGS. 23 and 24. [Diagram 31] 25A-25C are schematic side views showing a sequence for placing a bypass tube in the duodenum using the instrumentation of FIGS. 23 and 24. [Diagram 32] 25A-25C are schematic side views showing a sequence for placing a bypass tube in the duodenum using the instrumentation of FIGS. 23 and 24. [Diagram 33] FIG. 13 is a schematic side view showing a second example using two mounting rings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0056] In the following description, the same reference numbers are used to indicate similar or equivalent features, whether or not they are described in detail. Thus, the description of one embodiment can be combined with another embodiment. Where a tube is described, the tube can optionally be a bypass tube or bypass conduit for bypassing a portion of the intestine to reduce nutritional intake.

[0057] 1 and 2, a tube 10 is shown for introduction into at least the duodenum D of a patient for the treatment of diabetes or obesity. The tube 10 may extend into the jejunum. A proximal end 10a of the tube may be positioned in the duodenum D proximal to the pylorus P as shown in FIG. 2, or may extend at least partially through the pylorus P. The tube 10 may optionally include a cuff or stent 12 to resist displacement from the implantation location toward the stomach. The tube 10 may optionally include a stiffener (not shown in FIGS. 1 and 2, but indicated by reference numeral 14 in subsequent figures) to prevent kinking of the tube 10 at the pylorus, which could create an obstruction.

[0058] The anchor 20 for the tube 10 includes a gastric bulb 22 for placement with the stomach S. The gastric bulb 22 has a collapsed state suitable for introduction into the stomach, for example through the patient's mouth, and an operative state in which the bulb 22 expands to define an anchor that resists displacement through the pylorus P.

[0059] The anchor 20 is connected or connectable to the tube 10 by any suitable connection, such as by one or more struts or one or more flexible tethers 18. Alternatively, the anchor 20 is attached directly to the tube 10.

[0060] In the illustrated example, bulb 22 is configured such that in the expanded state, the pressure within the bulb is (i) below atmospheric pressure and / or (ii) below ambient pressure within the stomach. Bulb 22 is permanently substantially unpressurized compared to ambient atmospheric pressure within the stomach. This is in contrast to balloons or bulbs of the type that are inflated and inflated from the inside by an inflation pressure.

[0061] For example, the absence of positive pressure within bulb 22 allows bulb 22 to partially collapse in response to stomach contractions. This allows bulb 22 to at least partially follow stomach contractions and absorb the contractions without excessively pulling on tube 10 that could otherwise displace tube 10 into the stomach. Bulb 22 can partially compress to absorb or accommodate extreme, temporary stomach contractions, for example, if the patient vomits. At the same time, bulb 22 is biased to its operative state which functions to prevent distal displacement, since bulb 22 resists passage toward and through the pylorus.

[0062] In the illustrated example, the bulb 22 is self-expandable from the collapsed state to the operative state. The gastric bulb 22 can comprise a self-expanding structure 24 (shown partially and diagrammatically in FIG. 2), optionally a frame structure (e.g., having ribs and / or struts), and / or a mesh structure.

[0063] In one version, gastric bulb 22 may be open to its interior and / or may have a communicating opening that allows chyme to enter the interior of bulb 22. For example, bulb 22 may include an open frame 24.

[0064] Alternatively, the bulb 22 may comprise a fluid-tight chamber. The chamber may have an inlet port 26 to allow fluid to be drawn into the chamber as the gastric bulb 22 expands to its operative state, for example under the influence of the self-expanding properties provided by the self-expanding frame 24. The delivery device may include an inflow conduit (e.g., a vent channel) removably coupled to the inlet port 26 to allow pressure equalization and / or inflation by inflow of fluid. The fluid may be, for example, a liquid (e.g., saline) or a gas (e.g., air). After pressure equalization and / or inflation is complete, the inflow conduit may be disconnected from the inlet port 26, thus sealing the chamber. A small amount of fluid in the chamber may provide a soft cushion that complements the self-expanding frame 24, resulting in an atraumatic anchor with soft properties. Optionally, the fluid-tight chamber may include a central passage (not shown) to allow chyme to pass toward the pylorus and inlet to the tube 10.

[0065] When both a self-expanding structure and a fluid-tight chamber are provided, the self-expanding structure and the fluid-tight chamber may be at least partially (optionally substantially completely) nested one within the other. For example, the fluid-tight chamber may be at least partially (optionally substantially completely) nested with the self-expanding structure. A surface (e.g., an outer surface) of the fluid-tight chamber may be in surface-to-surface contact (e.g., laminated) with a surface (e.g., an inner surface) of the self-expanding structure.

[0066] With or without self-expanding, the bulb may comprise a fluid-tight chamber without a separate self-expanding structure. The fluid-tight chamber may have an inlet port for admitting fluid into the chamber. A further alternative to self-expanding is for the fluid-tight chamber to be made of a resilient material that self-expands, for example, to a molded configuration of the fluid-tight chamber into a deployed configuration.

[0067] Figure 3 shows a second example similar to the first example of Figures 1 and 2. The main difference in Figure 3 is the addition of an adjustment mechanism 28 to allow the distance between the bulb 22 and the proximal end 10a of the tube 10 to be set in situ prior to introduction into the stomach and / or during or after placement in the stomach. The adjustment mechanism 28 may include, for example, a screw thread and a rotatable nut. The adjustment mechanism 28 may be adjusted by manual rotation with an appropriate instrument or by magnetic rotation with a magnetic instrument.

[0068] Referring to FIG. 4, an alternative example of anchor 20 is shown that includes at least one elastic element 29 expandable from a collapsed state for introduction into the stomach and an expanded operating state (FIG. 4) in which elastic element 30 has an at least partially helical shape.

[0069] The helical shape can gradually move away radially from the proximal end of the tube. The helical shape may include open spaces between adjacent turns or turns of the helix.

[0070] Such a configuration may be advantageous to easily collapse for introduction while at the same time expanding to a relatively large size in its operating state. The helical shape may provide an atraumatic, flexible engagement that can absorb and accommodate gastric contractions, even strong transient contractions, without excessively pulling on the tube 10. At the same time, the helical shape securely anchors the tube 10 to prevent displacement through the pylorus. The anchor 20 may be collapsed by pulling on the free end of the helical shape using an appropriate retrieval instrument, allowing the device to be removed if necessary.

[0071] 5-7 show further examples including one or more gastric bulbs or balloons 22 configured to induce satiety through contact with the stomach wall. The balloons may or may not function as gastric anchors, depending on the implementation. Where appropriate, gastric anchor 20 is coupled to the proximal end of tube 10.

[0072] The bulb or balloon 22 can optionally be inflated with a fluid (e.g., gas or liquid). A gas, e.g., air, may be desirable to cause the balloon to float relative to the stomach contents. In Figure 5, at least one (optionally multiple) balloons 22 are tethered to the proximal end of the tube 10 so as to float upward relative to the stomach contents.

[0073] 6, at least one (optionally multiple) balloons 22 have magnetic properties such as a magnetic coating or carry one or more magnetic elements 27. Magnetic repulsion between balloon 22 and a similarly oriented magnetic element (not shown) at the proximal end of tube 10 urges balloon 22 away from tube 10 and toward contact with the stomach wall.

[0074] 7, multiple balloons 22 occupy a significant amount of space within the stomach and press against the stomach wall. The balloons 22 may be free and / or constrained to one another. The balloons 22 may be free and / or constrained to the tube 10.

[0075] In the above example of FIGS. 5-7, the balloon or balloons 22 are sized to allow for stomach movement and contractions and to allow chyme to pass into the tube 10.

[0076] 8-10, the anchor 20 comprises a first ring 30 for fitting to the ventral side of the pyloric sphincter PS and a second ring 32 for fitting to the duodenal side of the pyloric sphincter PS. The first and second rings 30, 32 are connected to each other to clamp the pyloric sphincter PS between the rings 30 and 32. As can be seen from the details of FIG. 9, the first and second rings 30, 32 have different inner and / or outer diameters. In the illustrated form, one ring (e.g., the first ring 30) has an inner diameter that is approximately larger (or at least not substantially smaller) than the outer diameter of the other ring (e.g., the second ring 32).

[0077] Such anchors 20 can be firmly, but atraumatically, attached to the pyloric sphincter PS and provide good fixation even in the presence of strong gastric contractions. In particular, by offsetting one ring relative to another, the risk of tissue necrosis that can be caused by pinching between two identical diameter rings with the same clamping force can be reduced.

[0078] The first and / or second rings 30 and 32 may be collapsible to a collapsed state for introduction into the pylorus. The anchor 20 further comprises one of additional connecting elements 34 between rings 30 and 32 and coupled to rings 30 and 32 for selectively approximating the rings to one another for clamping the pyloric sphincter PS. In the illustrated form, the connecting element 34 comprises a filament (e.g., a suture). The filament engages rings 30 and 32 such that pulling on the filament pulls at least one ring toward the other.

[0079] Optionally, at least one of the rings 30, 32 may also be attached directly to the pylorus, for example by one or more tissue penetrating fasteners (similar to those shown in FIG. 10 below).

[0080] A tube (not shown) may be attached to one or more of the first and second rings 30, 32. The tube may be attached permanently or via a connector, such as a magnetic connector.

[0081] 10, in addition to the first and second rings 30, 32, the anchor 20 further comprises at least one inner ring 38 for surrounding the inner periphery of the pyloric sphincter PS. In the illustrated embodiment, first and second inner rings 38a and 38b are used. One of the additional connecting elements 40 between and connected to the inner rings 38a and 38b selectively brings the rings closer together to surround the inner periphery of the pyloric sphincter PS. In the illustrated form, the connecting element 40 comprises a filament (e.g., a suture). The filament engages the rings 38a and 38b such that pulling on the filament pulls at least one ring toward the other.

[0082] In use, the inner rings 38a, 38b may be positioned away from the pyloric sphincter PS after the second ring 32 is deployed. The inner rings 38a and 38b are retracted together to encircle the inner edge, followed by the deployment and / or retraction of the first ring 30, clamping the pylorus between the first ring 30 and the second ring 32. If desired, one (or both) of the first and second rings 30, 32 may be attached directly to the tissue of the pyloric sphincter, for example, by one or more tissue-piercing fasteners 42. In one example, the fasteners 42 are staples having, for example, a U-shaped configuration, with each limb of the U-shaped piercing the tissue and restrained by lateral stops 42a (e.g., defining a T-shape). Alternatively, the fastener 42 may be a tag pin that is inserted from one side of the tissue and has self-expanding lateral stops or wings extending from a central stem to restrain and hold the fastener on the opposite side of the tissue, preventing withdrawal from the first side.

[0083] Tube 10 may optionally be attached (eg, permanently or via an assemblable connection) to one of the rings, such as one of the inner rings 38a, 38b, as shown.

[0084] Referring to FIG. 11, a further example of a tube 10 is shown. The tube 10 is configured to extend from a proximal end 10a at the pylorus into the duodenum and possibly at least partially into the jejunum. The tube 10 may be made of a plastic, such as silicone or polyurethane. The proximal end 10a is configured to be attached directly to body tissue by sutures or staples 42 that penetrate the material of the tube 10. To prevent tearing of the plastic material, the proximal end includes a layer of suture-permeable and / or staple-permeable reinforcing fabric 46, optionally laminated to and / or incorporated within the plastic material. The fabric 46 may be a woven or nonwoven material. The fabric 46 may be made of a polymeric material, such as PET. Natural openings or spaces in the fabric material 46 allow for the passage of sutures or fasteners without breaking the fibers or filaments of the fabric itself. Thus, the fabric may prevent tear propagation within the plastic of the tube 10.

[0085] The proximal end 10a of the tube 10 may be widened to facilitate placement and attachment of the proximal end 10a.

[0086] Optionally, tube 10 includes a duodenal anchor 12, such as a stent, and / or a transpylorus reinforcement 14 to avoid the risk of kinking of tube 10 due to stomach movements.

[0087] In use, the tube 10 may be placed in the duodenum and optionally the jejunum. A surgical stapler may be used to staple the proximal end to tissue forming, for example, the pyloric sphincter in a manner similar to that shown in FIG.

[0088] Figures 12a-d show a further technique for fastening a tube 10, such as the tube of Figure 11. With reference to Figure 12a, the tube 10 is introduced through the patient's mouth and positioned at least in the duodenum, with the proximal end 10a of the tube 10 proximal to the pylorus. The tube 10 may be temporarily held in place by a mechanical device (not shown).

[0089] 12b, an instrument 70 is introduced through the mouth into the pyloric antrum. The instrument 70 includes a section of tubing including the fabric 46 and a hypotube needle that is used to pierce the stomach wall. A pledget 72 with attached sutures is inserted through the hypotube needle, through the fabric 46 and stomach wall, and deployed to the outside of the stomach wall, with the sutures trailing through the stomach wall and fabric 46.

[0090] 12c and 12d, the hypotube needle is retracted inside the stomach and a second pledget 74 is parachuted through the hypotube onto the same suture and deployed on the inner surface of the stomach wall. The suture is tightened between the two pledgets 72 and 74 to tightly pinch the stomach wall and fabric 46 at the proximal end of the tube. The suture is knotted and cut, and the pledgets 72 and 74 form independent fastenings. The same process is repeated at several different points around the proximal end of the tube 10 to secure the tube 10 to the stomach wall. The pledgets are attached so that the proximal end of the tube moves intimately with the stomach wall, providing a secure attachment of the tube 10 and avoiding irritation due to friction during stomach contractions. If it is then desired to remove the tube 10 from the stomach, an instrument can be inserted into the stomach to cut the suture and release the pledget 74 on the inner surface of the stomach wall, thereby releasing the tube 10.

[0091] 13a and 13b, a tube 10 for insertion into the gastrointestinal tract, optionally the duodenum, has an exterior surface defining at least one channel 46 extending at least partially in the axial direction of the tube. In one form, the channel 46 may be substantially axial, e.g. in the form of a grooved surface (FIG. 13b). Alternatively, the channel may be helical in the form of a threaded surface (FIG. 13a). The channel 46 may allow intestinal fluids, e.g. pancreatic fluids, to flow along the exterior of the tube 10 as in efferent intestine, avoiding fluid entrapment due to contact between the tube 10 and intestinal tissue.

[0092] 14 and 15, a tube 10 for assisting in an anastomosis 50, for example a gastro-jejunal anastomosis, is shown. The anastomosis may be, for example, between the fundus of the stomach and the jejunum, or between a cut stomach and the jejunum (as shown in FIG. 14). The tube 10 may optionally include an anchor 20 for securing to the anastomosis 50. The anchor may include any of the features described above. Optionally, the anchor may include any of the features of FIGS. 8-10.

[0093] Tube 10 may function to prevent or reduce the reflux of pancreatic juices (indicated by arrow 58) originating from pancreas 60 from passing through anastomosis 50. For example, tube 10 is placed in the portion of the jejunum that leads to the large intestine. Stomach contents (arrow 60) passing through the anastomosis are directed in their normal flow direction towards the large intestine. Pancreatic juices (arrow 58) arriving from upstream in the jejunum are directed outside of tube 10, thus away from anastomosis 59 and towards the large intestine, thereby reducing the likelihood of reflux of these juices through anastomosis 50.

[0094] Tube 10 may also be configured to have directional flow characteristics to permit flow of stomach contents (e.g., chyme) in a first direction through tube 10, away from the stomach (arrow 62), and prevent flow in an opposite, second direction through tube 10. The unidirectional characteristics may also prevent reflux of intestinal fluids, such as pancreatic fluids, in jejunal loop 54 through anastomosis 50 toward the stomach, thereby reducing stomach discomfort for the patient.

[0095] The one-way property of the tube may be implemented by at least one, and optionally multiple, flaps 56 (FIG. 15) provided on the interior of the tube 10. The flaps may have a flexible and / or loose annular shape or may comprise individual arcuate segments. The flaps 56 are directed towards the outlet. Flow in a first direction (arrow 62) presses the flaps 56 against the wall of the tube 10 to allow flow. Flow in the reverse direction tends to press the flaps 56 inwards towards the center of the channel, narrowing the channel in the tube 10 and thus preventing flow. Alternatively, the tube 10 itself may be collapsible like a sock to perform a one-way valve function. Flow in a first direction opens and expands the tube 10. Flow in an opposite second direction causes the tube to collapse on itself and prevent flow.

[0096] 16 and 17, a further illustrated technique for treating diabetes or obesity involves reducing the natural volume of the stomach by creating one or more pleats 82 (or artificial plications) in the stomach wall with at least one tissue penetrating fastener 80. In the illustrated example, the fastener 80 is a staple having T-shaped limb ends, optionally with a U-shaped profile, as described above. The fastener may be placed, for example, by endoscopic or laparoscopic techniques.

[0097] The one or more pleats 82 may extend generally in a direction from (i) the upper to the lower part of the stomach, and / or (ii) from the esophagus to the pylorus. Such pleats 82 may form a generally sleeve-shaped cavity or passageway within the stomach.

[0098] 18, a gastric reduction pleat 82 may also be used in combination with a tube 10, optionally in combination with an anastomosis 50, such as a gastrojejunostomy 50. The pylorus P may be closed or plugged by a closure device 84. The closure device 84 may comprise, for example, a ring similar to those described in Figures 8-10 above for anchoring to the pyloric sphincter.

[0099] 19-33 show further examples of fixation of tube 10 to pylorus P using tissue penetrating fastener 100. FIG.

[0100] 19 and 20, each fastener generally comprises two end pieces in the form of a head 102 and a foot 104 connected via a connecting element 106. The head 102 and foot 104 are generally atraumatic in shape, for example rounded rod-like. In the illustrated example, the head 102 and foot 104 are tubular, allowing the pieces to be carried around a piercing needle 108 (FIGS. 21 and 22) for introduction and deployment. The head 102 and foot 104 may be rigid or semi-rigid elements, optionally made of a shape memory alloy, for example Nitinol.

[0101] The connecting element 106 can be rigid or flexible. In the example of Fig. 19, the connecting element 106 is generally straight. In the example of Fig. 20, the connecting element 106 has the form of an elongated spring for generating a compressive load when the spring is stretched.

[0102] At least the head 102, and optionally the foot 104, can be in a generally undeployed configuration (FIGS. 21 and 22) in which the head (and optionally the foot) extends alongside the connecting element for streamlined deployment. In the deployed configuration (FIGS. 19 and 20), the head (and optionally the foot) moves to project laterally on either side of the connecting member.

[0103] 23 and 24, an apparatus 120 is shown for attaching a ring 122 of a duodenal tube 10 to the pylorus P of a patient using the fastener 100.

[0104] The instrument 120 includes a plurality (e.g., three in the illustrated embodiment) of first elongate supports 124 attached to the ring 122 for introducing the ring into the pylorus and retaining the ring during deployment of the fastener. For example, the first elongate supports 124 may be attached to the inner core of the ring 122 by suture loops 126. The suture loops 126 can pass through the elongate supports and can be released from one end when it is desired to separate the elongate supports 124 from the ring 122.

[0105] The device 120 further comprises a plurality (e.g., three in the illustrated embodiment) of second elongate supports 128, each having a piercing needle 108 at its free end. A safety suture 138 passes through the second elongate supports and can be looped through or around the fastener 100 to prevent premature dislodging of the fastener 100 from the needle 108.

[0106] The instrument 120 further comprises a multi-lumen catheter shaft 132 having lumens for receiving a plurality of first and second elongate supports 124 and 128. The first and second supports 124 and 128 may be circumferentially staggered such that each first elongate support 124 is disposed between two adjacent second elongate supports 128, or vice versa. At least the second elongate supports 128 are axially slidable between an axially extended position and an axially retracted position to cause the needles 108 to penetrate tissue, as described below. The first elongate supports 124 may also be axially slidable, if desired.

[0107] The device 120 further comprises a constraining sheath 134 slidable over the catheter shaft 132. The constraining sheath 132 can constrain the first and second elongate supports 124, 128 in a radially compressed configuration (FIG. 23) for introduction through the stomach into the duodenum. Retraction of the constraining sheath 134 allows the first and second elongate supports 124 and 128 to move apart or spread outwardly to a radially expanded configuration (FIG. 24). The first elongate support 124 and / or the second elongate support 126 may be pre-shaped to spread outwardly when the constraining effect of the sheath 134 is removed. The constraining sheath may also serve to restrain the ring 122 in the radially compressed configuration for delivery. Similar to what has already been described above, the ring may be expandable to its working size when released from the sheath 134.

[0108] The multi-lumen shaft 132 has a hollow interior channel 136 that defines a receiving space for the tube 10. The instrument 120 may further include a gripper 136 for releasably grasping and controlling the distal end of the tube 10.

[0109] Figures 25-32 show a procedure for introducing and attaching tube 10 through the stomach using device 120. In Figure 25, device 120, containing tube 10 and ring 122 in their collapsed configuration, is advanced through stomach S, through pylorus P, and into duodenum D.

[0110] Referring to FIG. 25, the distal end of tube 10 is advanced from sheath 134 by advancing gripper 136 over guidewire G into the duodenum.

[0111] Referring to FIG. 27, the restraining sheath 134 is retracted relative to the shaft 132 to release the ring 122 attached to the proximal end of the tube 10 and allow the ring 122 to expand toward its functionally operable size.

[0112] 28, slight tensioning of the first elongate support 124 allows the ring 122 to seat against the first (duodenal) pyloric sphincter tissue. Further retraction of the sheath 134 allows the second elongate support 128 to expand and present the needle 108 carrying the fixation device 100.

[0113] 29, the needle 108 carrying the fastener penetrates the pyloric sphincter tissue and into the ring 122 by advancing or sliding the second elongated support 128 distally. In the example shown, the needle 108 also penetrates the ring 122 until the fastener head 102 passes through to the other side. The first elongated support may remain attached to the ring 122 to provide counter support to the ring 122 while the needle 108 is advanced.

[0114] With reference to FIG. 30, the second elongate support 128 is partially retracted, allowing the head 102 of the fastener 100 to deploy laterally and fasten distally against the ring 122.

[0115] 31, the second elongate support 128 is fully retracted, and the feet 104 of the anchor also deploy laterally, allowing anchoring against the pyloric sphincter from the opposite side of the ring 122. The safety suture for the anchor may be released by pulling on one end of the suture to separate the needle 108 from the anchor 100.

[0116] 32, the first elongate support 124 is released from the ring 122, leaving the ring 122 permanently and securely attached to the pyloric sphincter. The restraining sheath 134 can be advanced to provide an atraumatic covering over the exposed ends of the first and second elongate supports 124 and 128.

[0117] 33 shows a second example of using a second ring 122a in addition to the ring 122 to sandwich the pyloric sphincter from both sides. The second ring 122a may be carried and / or attached by a second elongated support 128, allowing the second ring to be guided into contact with the pyloric sphincter as the second elongated support 128 advances. As the second elongated support 128 advances further, the needle 108 penetrates completely through the second ring 122a. For example, the second ring 122a may be attached using a suture loop similar to the loop 126 already described for the first ring 122.

[0118] It will be understood that the above description is merely illustrative of examples of the invention and does not limit the scope of protection. Protection is claimed for any novel features or ideas disclosed in the specification and / or drawings, whether or not emphasis is placed on them.

Claims

1. An anchor (20) for securing a tube (10) to a patient's pylorus, the anchor comprising a gastric bulb (22) connected or connectable to a proximal end of the tube, the gastric bulb (22) being expandable from a collapsed state for introduction into the stomach to an operating state within the stomach.

2. The anchor of claim 1 , configured such that in the expanded state, the pressure within the bulb (22) is subatmospheric.

3. The anchor of claim 1 or 2, configured such that in the expanded state, the pressure within the bulb (22) is equal to or less than the ambient pressure within the stomach.

4. 4. The anchor of claim 1, 2 or 3, wherein the gastric bulb (22) is configured to partially collapse in response to stomach contractions.

5. The anchor of any one of claims 1 to 4, wherein the gastric bulb (22) is self-expandable from the collapsed state to the operative state.

6. The anchor of claim 5, wherein the gastric bulb (22) comprises a self-expanding structure (24).

7. The anchor of claim 6 , wherein the self-expanding structure comprises a frame structure and / or a mesh structure.

8. 8. An anchor according to claim 6 or 7, wherein the gastric bulb (22) has a communicating opening that allows the passage of chyme into the interior of the bulb.

9. 9. The anchor of any one of claims 1 to 8, wherein the gastric ball (22) comprises a fluid-tight chamber and an inlet port (26) for (i) allowing fluid to be drawn into the chamber as the gastric ball expands to its operative state, and / or (ii) for allowing fluid to enter the chamber to inflate the gastric ball.

10. 9. The anchor of claim 6, 7, or 8, wherein the gastric bulb further comprises a fluid-tight chamber and an inlet port for allowing fluid to enter the chamber, the self-expanding structure and the fluid-tight chamber being at least partially nested one within the other.

11. The anchor of claim 10 , wherein the fluid-tight chamber is at least partially nested within the self-expanding structure.

12. 12. The anchor of any one of claims 1 to 11, wherein the bulb comprises a passageway configured to allow chyme to pass through the bulb.

13. 13. The anchor of any one of claims 1 to 12, wherein the bulb has or comprises at least one shape selected from a bell shape, a tulip shape.

14. 14. The anchor of any one of claims 1 to 13, wherein the gastric bulb (22) is (i) connected to the tube by one or more tethers (18) and / or struts, and / or (ii) attached directly to the tube.

15. 15. An anchor for securing a tube to a patient's pylorus, the anchor comprising a first ring (30) for engaging a stomach side of a pyloric sphincter and a second ring (32) for engaging a duodenum side of the pyloric sphincter, the first and second rings (30, 32) being connected to one another to clamp the pyloric sphincter therebetween, the first and second rings (30, 32) having different inner and / or outer diameters, optionally one ring having an inner diameter larger than the outer diameter of the other ring, optionally the anchor (20) according to any one of claims 1 to 14.

16. 16. The anchor of claim 15, wherein the first and / or second rings (30, 32) are collapsible to a collapsed state for introduction into the pylorus.

17. 17. The anchor of claim 15 or 16, further comprising connecting elements (34) between the rings and coupled to the rings for selectively approximating the rings to one another to tighten the pyloric sphincter, the connecting elements (34) optionally being filaments or sutures.

18. 18. The anchor of claim 15, 16 or 17, further comprising at least one inner ring (38) for surrounding an inner periphery of the pyloric sphincter, optionally said at least one inner ring comprising first and second inner rings (38a, 38b).

19. 19. The anchor of claim 15, 16, 17 or 18, wherein the first and / or second rings comprise one or more of a metal, and / or a shape memory alloy, optionally Nitinol, and / or a plastic.

20. 20. An anchor (20) for securing a tube relative to a patient's pylorus, optionally according to any one of claims 1 to 19, said anchor comprising at least one elastic element (29) expandable from a collapsed state for introduction into the stomach to an expanded operating state in which said elastic element has an at least partially helical shape.

21. 21. The anchor of claim 20, wherein (i) the resilient member (29) defines a helical shape that gradually expands radially away from the proximal end of the tube, and / or (ii) the helical shape includes open spaces between adjacent turns or windings of the helix.

22. 22. A tube configured for insertion into the gastrointestinal tract, the tube comprising the anchor of any one of claims 1 to 21.

23. 23. The tube of claim 22, wherein the portion of the tube configured to fit into the pylorus comprises a reinforcement to prevent kinking of the tube.

24. 10. A tube (10) optionally comprising an anchor according to claim 22 or 23, or optionally according to any of claims 1 to 21, said tube configured for insertion into the gastrointestinal tract, said tube configured to allow passage of stomach and / or intestinal contents in a first direction and to obstruct passage of stomach and / or intestinal contents in an opposite second direction.

25. 25. The tube of claim 24, comprising at least one, and optionally a plurality of, valve elements (56) configured to permit passage of stomach and / or intestinal contents in the first direction and to obstruct passage of stomach and / or intestinal contents in the second direction.

26. 26. The tube of claim 25, wherein the valve element (56) comprises a flap that opens to allow passage of stomach and / or intestinal contents in the first direction through the tube and closes to prevent passage of stomach and / or intestinal contents in the second direction.

27. 26. A tube (10) optionally according to any one of claims 22 to 26 and / or optionally comprising an anchor according to any one of claims 1 to 21, said tube being for introduction into the duodenum of a patient, said tube being made of flexible plastic and comprising a suture- and / or staple-permeable layer of woven or nonwoven fabric (46) near or at its proximal end, said fabric (46) allowing fixation of the tube into body tissue near or at the pylorus by suturing or stapling therethrough, said fabric being resistant to tear propagation in the plastic.

28. 27. A tube (10) optionally according to any one of claims 22 to 27 and / or optionally comprising an anchor according to any one of claims 1 to 21, said tube being for introduction into the gastrointestinal tract of a patient, said tube being provided on its outer surface with at least one open channel (46) extending at least partially axially and / or longitudinally relative to said tube for allowing gastric secretions to migrate outside said tube, said channel optionally having a shape selected from the group consisting of a spiral shape and / or a longitudinal groove around the outside of said tube.

29. 10. A device comprising a tube (10) optionally according to any of claims 22 to 28 and / or a tube (10) optionally comprising an anchor according to any of claims 1 to 21, wherein said tube (10) is for introduction into the gastrointestinal tract of said patient, said device optionally comprising or further comprising at least one gastric balloon (22) configured to compress the stomach wall away from the pylorus to induce a feeling of satiety in the patient.

30. 30. The device of claim 29, wherein the balloon is filled with gas to float within the stomach and / or the balloon is magnetically repelled from the tube and / or the balloon is tethered to the tube and / or multiple space-occupying balloons are provided nestled together.

31. 1. A tissue-penetrating fastener for use in attaching one or more rings to pyloric sphincter tissue, the fastener comprising end pieces in the form of a head and a foot, the end pieces being interconnected by a connecting element, the tissue-penetrating fastener being configured such that at least the head can be positioned in (i) a generally undeployed configuration in which the head extends alongside the connecting element for streamlined introduction, and (ii) a deployed configuration in which the head is moved to project laterally on either side of the connecting element.

32. 32. The tissue penetrating fastener of claim 31, wherein the feet are configured to be capable of being placed in (i) a generally undeployed configuration in which the feet extend alongside the connecting element for streamlined deployment, and (ii) a deployed configuration in which the feet are moved to protrude laterally on either side of the connecting element.

33. 1. An apparatus for securing a device to a patient's pylorus, said apparatus comprising: at least a first ring for attachment to the pyloric sphincter, said ring having a self-supporting shape; a plurality of tissue-penetrating fasteners that can be inserted into and / or penetrate the ring to attach the ring to the surface of the pyloric sphincter, optionally each tissue-penetrating fastener being a fastener according to claim 31 or 32; An apparatus comprising:

34. 34. The device of claim 33, further comprising a second self-supporting ring for placement on and anchoring to an opposite side of the pyloric sphincter from the first ring, thereby clamping the pyloric sphincter, the anchor optionally being configured to pass through both rings.

35. 35. An apparatus for attaching a device to body tissue at a patient's pylorus, said device optionally being an apparatus according to claim 33 or 34, said apparatus comprising a first plurality of elongated supports for removably attaching to a ring-shaped portion of said device, and a second plurality of elongated supports including penetrating elements for deploying tissue-penetrating fasteners in said ring-shaped portion of said device.

36. 36. The instrument of claim 35, wherein each of the second plurality of elongate supports is axially movable relative to the first plurality of elongate supports between an extended position in which the second elongate support extends substantially at least to or beyond a level reached by the first plurality of elongate supports, and a retracted position in which the second elongate support is retracted relative to the level reached by the first plurality of elongate supports.

37. 37. The device of claim 35 or 36, wherein each piercing element of each second elongate support comprises a sharp pointed needle and is configured to carry the tissue-piercing fastener around the piercing element for deploying the tissue-piercing fastener.

38. 38. The device of claim 35, 36, or 37, further comprising a multi-lumen catheter shaft having multiple lumens for the first and second pluralities of elongate supports, the first and second pluralities of elongate supports being circumferentially alternatingly arranged about the catheter shaft.

39. 1. A method of attaching a device including a ring to a patient's pylorus, said method comprising: (a) advancing an instrument into the pylorus, the instrument including first and second pluralities of elongated supports, the ring attached to the first pluralities of supports, and the second pluralities of elongated supports including piercing elements and carrying fasteners for fastening to tissue; (b) positioning the ring adjacent a first side of a pyloric sphincter and the second elongate support on a second, opposite side of the pyloric sphincter; (c) individually or collectively advancing each of the second elongate supports such that the piercing elements penetrate the pyloric sphincter and into the ring on the first side; (d) partially withdrawing each of the second elongate supports individually or collectively so that a first end piece of the fastener secures the ring on the first side of the pyloric sphincter; (e) individually or collectively withdrawing each of the second elongate supports so that a second end piece of the fastener is secured to the second side of the pyloric sphincter; Including, a method.

Images