Endoscopic implant system and method

TECHNICAL FIELD OF THE INVENTION

0001The present invention relates to the field of systems for use in endoscopically implanting devices within the gastrointestinal system.

BACKGROUND

0002An anatomical view of a human stomach S and associated features is shown in <figref idref="f0001">Fig. 1</figref>. The esophagus E delivers food from the mouth to the proximal portion of the stomach S. The z-line or gastro-esophageal junction Z is the irregularly-shaped border between the thin tissue of the esophagus and the thicker tissue of the stomach wall. The gastro-esophageal junction region G is the region encompassing the distal portion of the esophagus E, the z-line, and the proximal portion of the stomach S.

0003Stomach S includes a fundus F at its proximal end and an antrum A at its distal end. Antrum A feeds into the pylorus P which attaches to the duodenum D, the proximal region of the small intestine. Within the pylorus P is a sphincter that prevents backflow of food from the duodenum D into the stomach. The middle region of the small intestine, positioned distally of the duodenum D, is the jejunum J.

0004Several prior applications, including U.S. Publication No. <patcit id="pcit0001" dnum="US20070276432A"><text>US 2007/0276432</text></patcit> having a priority date of October 8, 2004 and U.S. Publication No. <patcit id="pcit0002" dnum="US20080065122A"><text>US 2008/0065122, filed May 23, 2006</text></patcit> describe methods according to which medical implants are coupled to tissue structures, such as plications or folds, formed within the stomach. Examples of methods and devices for forming such tissue structures are described in U.S. Publication No. <patcit id="pcit0003" dnum="US20070219571A"><text>US 2007/0219571</text></patcit> (entitled ENDOSCOPIC PLICATION DEVICES AND METHOD), filed October 3, 2006, <patcit id="pcit0004" dnum="US90075707A" dnum-type="L"><text>U.S. Application No. 11/900,757</text></patcit> (entitled ENDOSCOPIC PLICATION DEVICE AND METHOD), filed September 13, 2007, and <patcit id="pcit0005" dnum="US05016908A" dnum-type="L"><text>U.S. Application No. 12/050,169</text></patcit> (entitled ENDOSCOPIC STAPLING DEVICES AND METHODS), filed March 18, 2008.

0005As disclosed in these prior applications, more robust and long lasting coupling between the implant and the surrounding stomach wall tissue is achieved when the plications/folds are formed by retaining regions of serosal tissue (i.e., the tissue on the exterior surface of the stomach) in contact with one another. Over time, adhesions form between the opposed serosal layers. These adhesions help to create strong bonds that can facilitate retention of the plication/fold over extended durations, despite the forces imparted on them by stomach movement and implanted devices

0006Several of the disclosed methods for forming tissue plications include a step in which a hole or cut is formed in the plication, using the plication device or other devices. An example of this type of plication is shown in <figref idref="f0002">Fig. 2A</figref>. This application discloses a system for attaching a medical implant to cutouts of this type, or to other types of openings in the plications (e.g., cuts, slits, perforations, tissue tunnels, etc.).

0007<patcit id="pcit0006" dnum="US20040092892A1"><text>US 2004/0092892 A1</text></patcit> discloses apparatus and methods for treatment of morbid obesity. The apparatus includes a system of components that may be used separately or in combination. The components include an artificial stoma device, a gastric sleeve device, an intestinal sleeve device, a combined gastrointestinal sleeve device and permanent and detachable attachment systems. Also described are devices for delivering and deploying the components of the system.

BRIEF DESCRIPTION OF THE DRAWINGS

0008<ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">Fig. 1</figref> is a schematic illustration of a human stomach and a portion of the small intestine.</li><li><figref idref="f0002">Fig. 2A</figref> is a partial section of a stomach wall showing a stomach wall plication having an opening formed in it.</li><li><figref idref="f0002">Fig. 2B</figref> is a cross-section view taken along the plane designated 2B-2B in <figref idref="f0001">Fig. 1</figref>, and illustrating five plications formed in a gastro-esophageal junction region of the stomach.</li><li><figref idref="f0003">Fig. 3</figref> shows an endoscopic implant system.</li><li><figref idref="f0004">Fig. 4A</figref> is a perspective view of the anchor of the implant system of <figref idref="f0003">Fig. 3</figref>.</li><li><figref idref="f0004">Fig. 4B</figref> is a perspective view of the anchor of <figref idref="f0004">Fig. 4A</figref>, showing the head separated from the stem.</li><li><figref idref="f0005">Figs. 5-7</figref> are partial section views of a human stomach schematically illustrating the anchor of <figref idref="f0004">Fig. 4A</figref> positioned in an opening in a stomach wall plication.</li><li><figref idref="f0006">Fig. 8A</figref> is a perspective view of an anchor hand-off tool.</li><li><figref idref="f0006">Figs. 8B</figref> and <figref idref="f0007">8C</figref> are perspective views showing the anchor coupled to the anchor hand-off tool.</li><li><figref idref="f0008">Fig. 9A</figref> is a side elevation view of an anchor grasper in the open position.</li><li><figref idref="f0008">Fig. 9B</figref> shows the distal end of the anchor grasper of <figref idref="f0008">Fig. 9A</figref> in the closed position.</li><li><figref idref="f0008">Fig. 10A</figref> is a top plan view of the anchor grasper of <figref idref="f0008">Fig. 9A</figref>.</li><li><figref idref="f0008">Fig. 10B</figref> is a cross-section view taken along the plane designated 10B-10B in <figref idref="f0008">Fig. 10A</figref>.</li><li><figref idref="f0009">Figs. 11A and 11B</figref> are side elevation views of the distal end of an alternative anchor grasper.</li><li><figref idref="f0009">Fig. 12A</figref> shows a top perspective view of a first embodiment of a restrictor.</li><li><figref idref="f0010">Fig. 12B</figref> shows a side perspective view of a second embodiment of a restrictor.</li><li><figref idref="f0010">Fig. 12C</figref> shows a top perspective view of a third embodiment of a restrictor.</li><li><figref idref="f0011">Fig. 13</figref> shows a top perspective view of a fourth embodiment of a restrictor.</li><li><figref idref="f0011">Fig. 14A</figref> shows a side perspective view of a fifth embodiment of a restrictor.</li><li><figref idref="f0011">Fig. 14B</figref> is a perspective view of the embodiment of <figref idref="f0011">Fig. 14A</figref>, showing only the rib structure.</li><li><figref idref="f0012">Fig. 15A</figref> is a side elevation view of a restrictor guide.</li><li><figref idref="f0012">Fig. 15B</figref> is a cross-section view of the restrictor guide taken along the plane designated 15B-15B in <figref idref="f0012">Fig. 15A</figref>.</li><li><figref idref="f0012">Fig. 16A</figref> is a perspective view of the distal portion of the restrictor guide, showing the mount in the open configuration.</li><li><figref idref="f0013">Fig. 16B</figref> is similar to <figref idref="f0012">Fig. 16A</figref> and shows the mount in the closed configuration.</li><li><figref idref="f0013">Fig. 16C</figref> is a cross-section view of the mount in the open configuration.</li><li><figref idref="f0014">Fig. 17A</figref> is a perspective view of a restrictor, showing the restrictor positioned on the restrictor guide, with the mount in the open configuration.</li><li><figref idref="f0014">Fig. 17B</figref> is similar to <figref idref="f0014">Fig. 17A</figref> but shows the mount in the closed configuration.</li><li><figref idref="f0015">Fig. 17C</figref> is a perspective showing the interior of a restrictor positioned on the restrictor guide.</li><li><figref idref="f0016">Fig. 18A</figref> is a perspective view showing the proximal end of the restrictor guide.</li><li><figref idref="f0016">Fig. 18B</figref> is a perspective view showing the distal portion of the multi-lumen portion of the restrictor guide.</li><li><figref idref="f0017">Figs. 19A and 19B</figref> schematically illustrate elements of the system positioned in the stomach in preparation for transferring an anchor from an anchor hand-off to the anchor grasper that will then draw the anchor through the opening in the plication.</li><li><figref idref="f0018 f0019 f0020">Figs. 20A - 20F</figref> schematically illustrate transfer of the anchor from the anchor hand-off to the anchor grasper within the stomach.</li><li><figref idref="f0021">Figs. 21A and 21B</figref> are perspective views showing the anchor grasper engaging different portions of the anchor head.</li><li><figref idref="f0022">Figs. 22A - 22C</figref> schematically illustrate a plurality of anchors that have been placed in plications in the stomach, together with elements of the disclosed system.</li><li><figref idref="f0023">Fig. 23</figref> is a perspective view of the proximal end of the endogastric tube, showing use of the tool organizer.</li><li><figref idref="f0024">Fig. 24A</figref> is a perspective view of a restrictor being advanced onto proximal ends of a collection of anchor graspers.</li><li><figref idref="f0024">Fig. 24B</figref> is a perspective view similar to <figref idref="f0024">Fig. 24A</figref> showing the restrictor advanced further along the anchor graspers.</li><li><figref idref="f0025">Fig. 25A</figref> is a schematic illustration showing the downstream side of a restrictor within the stomach, anchored to plications using anchors.</li><li><figref idref="f0025">Fig. 25B</figref> is a schematic illustration showing the upstream side of a restrictor within the stomach, anchored to plications using anchors.</li><li><figref idref="f0026">Figs. 26A - 26D</figref> schematically illustrate use of the plicator for forming tissue plications and for forming holes in the plicated tissue.</li></ul>

DETAILED DESCRIPTION

0009<figref idref="f0002">Fig. 2B</figref> is a schematic cross-section view of the stomach, looking distally into the stomach interior. In this view, five tissue plications P having openings such as cutouts C are shown to have been formed in the stomach wall tissue. This view would seem to illustrate clear access via the esophagus to the plications and cutouts using endoscopic instruments. However, the natural undulations and folds of the actual stomach tissue, and the constant movement of the stomach, limit the visibility of the cutouts and even the plications themselves, rendering it difficult to endoscopically access the cutouts in an actual human subject. The disclosed system facilitates access to the cutouts, and provides for an efficient method for coupling an implant to the cutouts.

0010<figref idref="f0003">Fig. 3</figref> illustrates an embodiment of an endoscopic implant system 10 that may be used for this purpose. In general, system 10 includes multiple anchors 12 (one shown) that are implanted in the cutouts and an implant 14 to be coupled to the anchors 12. The implant can be any type of implant to be anchored within the stomach. In the disclosed embodiment, the implant is a restrictor 14 designed to slow the rate at which food can enter the stomach from the esophagus.

0011An anchor hand-off 16 delivers the anchors into the stomach, and anchor graspers 18 (one shown) are used to position the anchors within the tissue openings and also to guide the restrictor 14 to the implanted anchors. A restrictor guide 20 is provided for advancing the restrictor into position in the stomach. An endogastric overtube 22 is provided for establishing a working channel between the mouth and the stomach. Other tools shown elsewhere in the drawings, such as a multi-lumen guide 24 (<figref idref="f0017">Fig. 19A</figref>), articulated guides 25 (<figref idref="f0017">Fig. 19A</figref>), and one or more endoscopes 26 (<figref idref="f0017">Fig. 19A</figref>) are additionally provided.

Anchor

0012One embodiment of an anchor 12 is shown in <figref idref="f0004">Fig. 4</figref>. A preferred anchor will pass though the opening C in the plication cutout with relative ease and minimal tissue trauma, but will resist pulling out of the opening in the cutout when subjected to the stresses imparted to it by the restrictor. Moreover, a preferred anchor will minimize the stress and strain on the stomach wall and distribute a given stress as evenly as possible so as to prevent the stomach's natural defense from engaging in an attempt to eliminate the anchors and restrictor.

0013Referring to <figref idref="f0004">Fig. 4A</figref>, the general features of the anchor 12 include a base 28, a stem 30, and a head 32. The anchor is formed using materials that are durable within the stomach environment. In one embodiment, the head 32 is molded out of a higher durometer compliant material (such as 50 shore A durometer Silicone) while the stem 30 and base 28 are molded out of a softer compliant material (such as 5 shore A durometer Silicone). Since the loading on the anchor from the restrictor implant can be seen as shear against the edges of the opening in the plication, the stem 30 is formed to have a relatively large diameter (2mm - 8mm) to minimize stress and abrasion on the stomach wall tissue inside the opening. The edges of the anchor are molded with generous fillet radii to minimize abrasion of stomach wall tissue.

0014Head 32 includes a ring 34 and a plurality of struts 36 coupling the ring 34 to the stem 30, and an elongate loop 38 extending from the ring 34. The anchor is elastically deformable to an elongated shape (see <figref idref="f0019">Figs. 20D</figref> and <figref idref="f0020">20E</figref>) in response to application of tension to the ring 34 or loop 38 (collectively referred to as the "rim"). This allows the anchor to be drawn into a streamlined shape so that it can be drawn through the opening in the plication and also through an opening in the restrictor. When the anchor is pulled from the rim, its shape lengthens and slims down to fit through a much smaller hole. For example in one embodiment, in its natural state the anchor has an outer head diameter of approximately .600 inch (15mm), but in its streamlined orientation it can fit through a plication opening of .200 inch (5mm). However, once implanted, the anchor's shape resists pull-out force to a higher degree since the rim is not being pulled and lengthened directly. Also in this embodiment, the base is designed so it will not pull through the hole and may have an outer diameter of approximately 1 inch (25.4mm)

0015Referring to the top view of the anchor 12 shown in <figref idref="f0005">Fig. 5</figref>, when an anchor is implanted in a plication opening, the anchor's proximity to the wall of the stomach with its enveloping rugae can make it difficult to find and grab onto the anchor when it is time to couple the restrictor implant to the anchors. The head 32 is shaped to have an undulating profile to enhance its visibility and accessibility when the anchor is positioned in a plication opening. The undulation of the head forces several of the elements of the head away from the wall to make them more visible and also to allow a grasping tool to latch onto one of those elements without also grabbing adjacent tissue.

0016Referring to <figref idref="f0005">Fig. 6</figref>, the base 28 is preferably formed to have an asymmetrical shape. In the illustrated example, one edge 40 of the base is formed to have a flatter curvature than that of the other edge 42 of the base. When implanted, the anchor self-orients to position the flatter edge 40 against the adjacent stomach wall as shown. Since the loop 38 of the head extends in a direction opposite to the side of the anchor on which the flatter edge 40 is position, this self-alignment causes the loop 38 to extend towards the center of the stomach as shown in <figref idref="f0005">Fig. 7</figref>. This makes it easier to find segments of the anchor head amongst the folds of the stomach which can envelope other segments.

0017Referring again to <figref idref="f0005">Fig. 6</figref>, the base 28 preferably includes a relatively large surface area (e.g., approximately 1 square inch, i.e. 6,45 cm²) so as to distribute the stress of holding the restrictive implant in place over a large percentage of the surface area of the tissue plication. Reinforcing ribs 44 may be positioned on the underside of the base, radiating from the stem to the edges of the base, to facilitate distribution of stress while minimizing the overall weight of the base.

Anchor Hand-Off Tool

0018Anchor hand-off 16 is an instrument used to deliver individual anchors to the implantation site, and to hand-off each anchor to an anchor grasper which pulls the anchor through an opening in a plication.

0019Referring to <figref idref="f0006">Fig. 8A</figref>, one embodiment of an anchor hand-off 18 includes a torqueable elongate shaft 46 having a wire element 48 extending from its distal end and attachable to an anchor.

0020In one embodiment, the anchor hand-off 16 has a horseshoe shaped form with an opening 45 that narrows to form a constriction 47. The stretchable nature of the anchor stem 30 allows it to be squeezed through the constriction 47 and thus held in place by friction. See <figref idref="f0006 f0007">Figs. 8B - 8D</figref>. Upon pulling on the head portion 32 by the anchor grasper, 18, the stem 30 elongates and passes out of the horseshoe shaped constriction.

0021Shaft 46 is slidably disposed in an articulating guide 49 that will articulate in response to actuation using pull wires or other means known to those skilled in the art. The articulating guide 26 may be one with video capability, for example it might be an articulating endoscope. In one embodiment, wire element 48 is detachable from the shaft 46 of the anchor hand-off 16 to allow shaft 48 to pass through a small diameter tool channel in the articulating guide 26. Once the distal end of the shaft 46 reaches the distal end of the guide 26, the wire element 48 is coupled to the shaft 46.

0022Furthermore, the anchor hand-off tool 16 may be designed to hold the anchor behind (or axially off-set from) the distal tip of the articulating guide 26 with video capability. This facilitates greater visibility at the target site/plication by positioning the held anchor out of the endoscope's field of view as shown in <figref idref="f0007">Fig. 8C and 8D</figref>. To perform the actual hand-off of the anchor 12, the user can extend and torque the hand-off tool 16 to position at least a portion of the anchor head 32 within the field of view.

Anchor Grasper Tool

0023Anchor grasper 18 is designed to couple to or engage a portion of the head 32 of an anchor 12. It is used to pull the anchor 12 through an opening in a plication, and to pull the anchor through a corresponding opening in a restrictor that is to be implanted. The anchor grasper 18 may have a variety of designs that allow these functions to be carried out. One such design is shown in <figref idref="f0008">Figs. 9A and 9B</figref> an employs a coupling/grasping element 50 that takes the form of a hook 52 having a gate 54 that closes against the opening in the hook 52. The hook and gate are naturally biased in the open position shown in <figref idref="f0008">Fig. 9A</figref>.

0024A closure tube 56 is longitudinally slidable over the hook and gate to lock them in the closed position, thus preventing them from separating. The collar and associated features are proportioned to ensure that when the grasping element 50 is to be locked, bending of the shaft of the anchor grasper 18 does not cause the closure tube 56 to slide into a position that will release the grasping element 50 from the locked position.

0025Referring to <figref idref="f0008">Fig. 10B</figref>, the closure tube 56 is mounted to a torqueable element 58 (preferably a coil), which in turn is coupled to outer tubing 60. An L-shaped slot 62 is formed in the outer tubing 60. As best shown in <figref idref="f0008">Fig. 10A</figref>, slot 62 includes a longitudinal segment 63a and a partially circumferential segment 63b.

0026Hypotube 64 is slidably and rotatably disposed within outer tubing 60, and includes a pin 66 disposed within the slot 62. Hypotube 64 is mounted to a tapered handle 68. A cable 70 has a distal end coupled to the grasping element 50 and a proximal end mounted to the handle 68.

0027To close and lock the grasping element, the outer tube 60 is advanced distally relative to the handle 68. Advancement of the outer tube 60 pushes the coil 58 and thus the closure tube 56 in a distal position until the closure tube 56 moves the grasping element 50 to the closed position shown in <figref idref="f0008">Fig. 9B</figref>. As the outer tube 60 moves distally, longitudinal segment 63a of the slot 62 slides over pin 66. The outer tube 60 is then rotated to cause positioning of pin 66 within the circumferential segment 63b of the slot 62, and to thereby lock the outer tube 60 in the distal position. To unlock the grasper element 50, the outer tube 60 is rotated in the opposite direction to release the pin 66 from the circumferential segment 63b. Since the closure tube is no longer locked in the distal position, the grasping element 50 moves to the open position due to its natural bias, thereby pushing the outer tube 60 in a proximal direction.

0028<figref idref="f0009">Figs. 11A and 11B</figref> show an alternative grasper element 50a which is moved between open and closed positions using a system 72 of linkages pivoted using a longitudinally slidable push rod 74.

Restrictor

0029The restrictor is an implant designed to slow the passage of food from the esophagus into the stomach. The illustrated embodiments, the restrictor is positioned in the stomach such that food enters the restrictor through a proximal opening and exits the restrictor through a distal opening. The restrictor and/or openings are proportioned to slow the rate at which food can move into or through the restrictor, and/or from the restrictor into the rest of the stomach.

0030A preferred restrictor is proportioned to be coupled to anchors that have been coupled to plications in the gastroesophageal junction region of the proximal stomach. In a preferred design, the restrictor 14 includes features that minimize pulling against the anchors when the restrictor encounters stress as a result of food moving through the restrictor and/or movement of the stomach. Minimizing pulling at the anchors is beneficial for minimizing stress on the stomach wall tissue coupled to the anchors. In general, the restrictor 14 is designed to have compliance between the anchor points (i.e., the points at which the implant is coupled to the tissue directly or using the anchors). This compliance may be achieved using the geometry of the restrictor 14 and/or using restrictor materials selected to give compliance between anchor points.

0031In a first embodiment shown in <figref idref="f0009">Fig. 12A</figref>, the restrictor 14 is a sleeve having a wall and a plurality of anchor openings 80 formed in the wall. The restrictor wall is an undulating wall defining multiple folds 76 that give it compliance even when molded from a relatively more stiff material (such as 30 shore A silicone). When viewed from the side (see the second embodiment 14a in <figref idref="f0010">Fig. 12B</figref>), it can be seen that the proximal edge of the restrictor 14 undulates to define peaks 78 in the profile of the proximal edge. When viewed from the top (<figref idref="f0009">Fig. 12A</figref>), it can be seen that the circumferential profile of the restrictor also includes peaks 82 extending radially outwardly. These peaks 82 define chutes 84 extending from the proximal peaks 78 towards a distal orifice 86. When the restrictor is implanted, the chutes 84 help to channel ingested material towards the distal orifice 86.

0032Anchor openings 80 are positioned between the radial peaks 82. These openings may be positioned in the portion of the wall that is at the most radially inward position as on the restrictor 14a of <figref idref="f0010">Fig. 12B</figref>, or the undulations in the wall may be such that the openings 80 are in a section of wall that is positioned between some inwardly extending folds 88 as in <figref idref="f0009">Fig. 12A</figref> (or that, in other words, forms smaller radial peaks 90 than the radial peaks 82).

0033Openings 80 may be surrounded by reinforced sections 92 formed using thicker regions of silicone, or a stronger material embedded in or attached to the silicone. Additional reinforcements such as ribs 94a, 94b may extend from the openings 80 towards the orifice 86 and/or from the proximal peaks 78 towards the orifice 86 and may be formed using similar techniques.

0034The edge of the wall defining the orifice 86 preferably includes folds or undulations 96, allowing the orifice to be compliant as well. In addition, small holes 98 are arranged around the orifice to allow the restrictor 14 to be coupled to the restrictor guide used to deliver the restrictor into the stomach.

0035An alternative restrictor 14b shown in <figref idref="f0010">Fig. 12C</figref> is similar to the restrictor of <figref idref="f0009">Fig. 12A</figref>, but is molded to be flat for ease of manufacturing, but assumes its undulating configuration at the folds when coupled to anchors at anchor openings 80.

0036Yet another alternative restrictor 14c (<figref idref="f0011">Fig. 13</figref>) is molded out of highly compliant material (such as 40 shore 00 silicone) to put minimal stress on attached stomach tissue. This embodiment includes a reinforced proximal rim 100.

0037An additional restrictor 14d is molded out of a combination of high and low compliance material (such as 50 shore A plus 40 shore 00 silicones) in different areas of the restrictor to achieve optimal performance. A rib structure 94c (see <figref idref="f0011">Fig. 14B</figref>) out of stiffer material serves to maintain the restrictor shape in the open position within the stomach. IN this example, rib structure 94c includes an undulating ring 94d encircling the orifice 86, and ribs 94e extending to peaks 78. In this manner, the rib structure 94c maintains apposition of the restrictor against the wall of the stomach in order to improve the effectiveness of catching food, particularly in the chutes 84. In addition to the stiffer rib structure, the assembled restrictor contains a very soft web 95 of material that forms the funnel shape and also serves to link together the anchor points 80 (see <figref idref="f0011">Fig. 14A</figref>). The soft compliant nature of the web material minimizes the stress to the plication tissue by allowing full flexibility.

Restrictor Guide Tool

0038Restrictor guide 20 generally includes a tubular shaft 101, a distal portion comprising a coupling element/mount 102 and a proximal portion 104.

0039In a preferred restrictor guide, the mount 102 is designed to support the restrictor 14 during delivery of the restrictor into the stomach and coupling of the restrictor 12 to the stomach wall (directly or using anchors or other means as disclosed herein). In the illustrated embodiment, mount 102 includes a collar 103 on the distal end of the shaft 101. A pair of tubes 112 extend distally between the collar 103 and a ring 107. Ring 107 includes a plurality of distally extending pins 106 and a central opening 109. A tube 111 is positioned co-axially with the opening 109. A distal cap 108 is mounted to the distal end of the tube 111. Cap 108 includes an opening positioned in alignment with the opening of the ring 107 and the lumen of the tube 111. Bores 110 in the cap are positioned so that proximal advancement of the cap 108 relative to the ring 107 causes pins 106 to enter the bores 110.

0040Referring to <figref idref="f0014">Figs. 17A</figref>, pins 106 are arranged to allow a user to couple the restrictor 14 to the restrictor mount by threading the holes 98 surrounding the orifice in the restrictor 14 over the pins 106 as shown. When the restrictor 14 is mounted in this way, the tube 111 is disposed in the orifice 86 of the restrictor, and the cap 108 is positioned distal to the restrictor. Restrictor 14 is retained on the mount 102 by moving the cap 108 in a proximal direction until bores 110 slide over the pins 106, thus capturing the restrictor 14 between the cap 108 and the ring 107 by preventing the restrictor from sliding off the pins. See <figref idref="f0014">Fig. 17B</figref>.

0041Drive rods 112a (<figref idref="f0012">Fig. 16A</figref>) extend through the tubes 112 and are coupled at their distal ends to flanges 120 on the proximal end of tube 111. The proximal ends of the drive rods 112a are advanceable by an actuator at the proximal end of the restrictor guide. Manipulation of the actuator will cause the drive rods 112a to move distally relative to the tubes 112, causing distal movement of the cap 108 relative to the ring 107. In one current embodiment, rotation of a threaded nut on the proximal handle moves a threaded piece inside the handle that is connected to wires or cables that communicate with the drive rods 112a. In another embodiment, the drive rods 112a may be lead screws, and the actuator may include a knob and associated gearing for rotating the lead screws such that they advance the cap 108 distally. Alternatively, the actuator may include a spring that is initially locked in a compressed position using a latch. According to this embodiment, a button or other element is manipulated by the user to disengage the latch, thus releasing the spring from the compressed position to drive the drive rods distally. Other alternatives include pneumatic or hydraulic actuation of the cap 108. In other embodiments, the actuator may be a handle that allows the user to manually advance the drive rods to advance the cap.

0042Proximal portion 104 of the restrictor guide 20 is a multi-lumen guide having a central lumen 114 through which the tubular shaft 101 extends, and a plurality of peripheral lumens 116 arranged around the central lumen. The peripheral lumens 116 are proportioned to accommodate the anchor graspers 18. Each of the peripheral lumens 116 has a proximal port fitted with a seal (which may be, for example, a duck bill seal) that will seal around the shaft of a grasper 18 positioned in the lumen, and that will self-seal when the grasper 18 is removed from the lumen.

Exemplary Procedure

0043Use of the system 10 to implant a restrictor 14 will next be described. According to one embodiment, the method is performed following an initial procedure in which a plurality of plications P having cutouts or other openings C are formed. In another embodiment, after each plication is formed, an anchor 12 is implanted in that plication's opening for the dual purpose of marking the location of the plication as well as ensuring that the opening does not close in the natural healing process of the tissue. The anchor implantation procedure may immediately precede restrictor implantation, or may instead be performed in advance of the restrictor implantation procedure to allow reinforcement of the plications through the body's healing process.

0044In the initial phase of the restrictor implantation procedure, anchors 12 are positioned in the openings of the plications P. Referring to <figref idref="f0017">Fig. 19A</figref>, the endogastric tube 22 is introduced into the mouth and through the esophagus, and parked with its distal opening in a portion of the stomach or esophagus that is proximal to the plications P. After each plication with opening is created, a multi-lumen (or cannulation) guide tube 24 may be passed through the endogastric tube 22. Multi-lumen guide tube 24 may have a central lumen 24a and peripheral lumen 24b in a similar arrangement to the lumen of the restrictor guide 20 (<figref idref="f0016">Fig. 18B</figref>).

0045Outside the body, an anchor hand-off 16 is passed through a tool channel of an endoscope 26 such that the anchor engaging wire 48 extends from the endoscope lumen. With the engaging wire in this position, an anchor 12 is coupled to the engaging wire 48, and the endoscope 26, anchor hand-off 16, and anchor 12 are together passed through the central lumen 24a of the multi-lumen guide tube 24 and into the stomach as shown in <figref idref="f0017">Figs. 19A and 19B</figref>. The endoscope 26 is retroflexed within the stomach to provide visualization of the plication P.

0046Next, an articulating guide 25 is advanced through a peripheral lumen 24b of the multi-lumen guide tube 24 and into the stomach. An anchor grasper 18 is positioned in the lumen of the guide 25. Under visualization using endoscope 26 (with anchor hand-off 18 retracted so that the anchor is out of view), guide 25 is articulated to orient the grasper 18 towards the opening C in the plication, and the grasper 18 is then advanced through the opening as also shown in <figref idref="f0017">Figs. 19A and 19B</figref>. The grasping element 50 of the grasper 18 is moved into the open position.

0047Referring to <figref idref="f0018">Figs. 20A, 20B</figref> and <figref idref="f0019">20C</figref>, anchor hand-off 16 is advanced further from the endoscope 26 until the head 32 of the anchor is positioned within reach of the grasping element 50. Grasping element 50 is manipulated to engage the head 32. While it is preferable to engage the loop 38 as shown in <figref idref="f0021">Fig. 21A</figref>, the structure of the head 32 allows for engagement of other portions of the head such as the struts 36 as shown in <figref idref="f0021">Fig. 21B</figref>, or the ring surrounding the struts 36. Engagement between the anchor and the anchor grasper is secured by moving the grasping element 50 into the locked position. Next, the anchor hand-off is retracted into the endoscope in order to separate it from the anchor grasper. This action results in stretching the anchor stem and thus causing it to release from the horseshoe shaped form. See <figref idref="f0019">Fig. 20D</figref>. The handle of the anchor grasper 18 is then withdrawn to pull the head 32 of the anchor through the opening C in the plication as in <figref idref="f0020">Fig. 20E</figref>. As discussed above, application of tension to the head 32 causes the anchor to elongate to a narrow profile that will pass readily through the opening C in the plication. The jaws of the anchor grasper 18 are opened to release the anchor 12. <figref idref="f0020">Fig. 20F</figref>.

0048The endoscope 26 and anchor hand-off 16 are withdrawn from the guide tube 24 along with the multiple lumen guide and articulating guide. After another plication is created, the process is repeated for each anchor that is to be implanted. See <figref idref="f0022">Figs. 22A - 22C</figref>.

0049As each anchor is implanted, its corresponding anchor grasper is preferably left coupled to the ring of the anchor, although it may instead be withdrawn from the body. At the end of the anchor-positioning phase of the procedure, each anchor is positioned extending through a plication opening (<figref idref="f0022">Fig. 22A</figref>). If the anchor graspers were left in place coupled to the rings of each anchor, the handles of each separate anchor grasper 18 extend out of the body. Organization of the anchor graspers 18 is maintained by the multi-lumen cannula 24.

0050If the anchor graspers 18 are not left in place following implantation of the individual anchors 12, the graspers 18 are re-coupled to the anchors prior to the restrictor-positioning phase. Specifically, each of the graspers 18 is reintroduced into the stomach and endoscopically guided by its corresponding articulated guide 25 into engagement with the head 32 of one of the anchors. As discussed in the <i>Anchors</i> section above, orientation of the loop 38 to extend in a direction opposite to the asymmetrical base 28 helps to orient the loop 38 centrally within the stomach so that the loops 38 may be more easily seen and engaged by the graspers 18.

0051The restrictor-positioning phase of implantation begins with each anchor that is to be coupled to the restrictor having a separate anchor grasper 18 coupled to it. If the multi-lumen guide 24 is still in use at this point, with individual ones of the graspers 18 in the peripheral lumen 24b, the guide 24 is withdrawn from the endogastric tube 22 and removed from the handles of the anchor graspers. The tapered proximal ends of the anchor graspers 18 allow the lumens 24b of the guide 24 to pass easily over them. Before the multiple lumen guide is completely removed from the endogastric tube 22, the anchor grasper tool shafts are locked into a tool organizer 130 at the proximal end of the endogastric tube 22 as shown in <figref idref="f0023">Fig. 23</figref>. Organizer 130 includes slots 132 positioned to receive the shafts of the graspers 18, leaving them arranged around the main lumen 134 of the endogastric tube. This serves to maintain the relative clocking of each grasper at the proximal end to a corresponding anchor location at the distal end.

0052The restrictor 14 is prepared for implantation by threading anchor openings 80 in the restrictor over the tapered proximal ends of the anchor graspers 18, which at this point are still extending out of the endogastric tube 22. <figref idref="f0024">Fig. 24A</figref>. The restrictor 14 is mounted to the mount 102 of the restrictor guide 20 in the manner disclosed in the <i>Restrictor Guide</i> section above. This step may be performed before or after the restrictor is threaded over the anchor graspers.

0053Next, the restrictor guide 20 is advanced over the tapered proximal ends of the anchor graspers 18, which are still extending out of the endogastric tube 22. The restrictor guide 20 is positioned so that each of its peripheral lumens 116 advances over a separate one of the anchor graspers 18. <figref idref="f0024">Fig. 24B</figref>. Continued distal advancement of the guide 20 advances the guide 20 and restrictor 14 through the endogastric tube 22 and into the stomach.

0054In a final step, the anchors 12 are pulled through the anchor openings 80 to couple the restrictor 14 to the anchors 12. In this step, distally-oriented pressure is applied to the restrictor guide 20 while the anchor graspers 18 are one-by-one pulled proximally, causing the anchors 12 to elongate sufficiently to pass through the openings 90. Coupling between each anchor and its corresponding opening 80 is confirmed visually and/or by tactile feedback reflecting the "pop" of the anchor moving through the opening 80. Once the restrictor 14 has been coupled to the anchors 12, the cap 108 of the restrictor guide 20 is advanced distally to release the restrictor as described in the <i>Restrictor Guide</i> section above. The anchor graspers 18 are unlocked and separated from the anchors. The restrictor guide 20, anchor graspers 18, guides, etc. are withdrawn from the body, leaving the restrictor 14 and anchors 12 in place as shown in <figref idref="f0025">Figs. 25A and 25B</figref>.

0055The system of <figref idref="f0003">Fig. 3</figref> may additionally include one or more tools for use in forming plications in the stomach wall tissue and for forming holes in the plicated tissue. Examples of such plicators are found in the following co-pending U.S. Patent Applications: U.S. Publication No. <patcit id="pcit0007" dnum="US20070219571A"><text>US 2007/0219571</text></patcit> (entitled ENDOSCOPIC PLICATION DEVICES AND METHOD), filed October 3, 2006, <patcit id="pcit0008" dnum="US90075707A" dnum-type="L"><text>U.S. Application No. 11/900,757</text></patcit> (entitled ENDOSCOPIC PLICATION DEVICE AND METHOD), filed September 13, 2007, and <patcit id="pcit0009" dnum="US05016908A" dnum-type="L"><text>U.S. Application No. 12/050,169</text></patcit> (entitled ENDOSCOPIC STAPLING DEVICES AND METHODS), filed March 18, 2008.

0056Use of one such tool is generally illustrated in <figref idref="f0026">Figs. 26A - 26D</figref> and includes drawing stomach wall tissue into a vacuum chamber of a plication head (<figref idref="f0026">Fig. 26A</figref>), compressing the tissue (<figref idref="f0026">Fig. 26B</figref>), advancing fasteners such as staples through the compressed tissue and forming a cut or hole in the compressed tissue (<figref idref="f0026">Fig. 26C</figref>), and releasing the tissue from the plication tool, leaving the plication with a hole or cut out through the plicated tissue. In one staple arrangement, a pair of annular staple patterns encircle the cut/hole. Anchors can be subsequently positioned within the hole/cutout as disclosed above.

0057Although the disclosed system has been described in the context of implanting a restrictor implants implantable in the stomach for limiting limit intake of food by the patient, the systems and methods may be used to implant other types of implants for a variety of purposes. These implants include, but are not limited to obstructive gastric implants that obstruct flow of food into the stomach, gastric space occupiers for limiting effective stomach volume, prosthetic valves for the treatment of gastro-esophageal reflux disease, gastric stimulators, pH monitors and drug eluting devices that release drugs, biologics or cells into the stomach or elsewhere in the GI tract. Such drug eluting devices might include those which release leptin (a hormone which creates feelings of satiety), Ghrelin (a hormone which creates feelings of hunger), octreotide (which reduces Ghrelin levels and thus reduces hunger), Insulin, chemotherapeutic agents, natural biologics (e.g., growth factor, cytokines) which aid in post surgery trauma, ulcers, lacerations, etc. Still other implants might be of a type which might provide a platform to which specific cell types can adhere, grow and provide biologically-active gene products to the GI tract, and/or a platform for radiation sources that can provide a local source of radiation for therapeutic purposes, or provide a platform whereby diagnostic ligands are immobilized and used to sample the GI tract for evidence of specific normal or pathological conditions, or provide an anchor point for imaging the GI tract via cameras and other image collecting devices. Additionally, the disclosed anchors and restrictors are shown positioned and anchored near the gastro-esophageal junction region of the proximal stomach, but may be positioned and/or anchored elsewhere in the stomach or GI system.

0058It should also be recognized that a number of variations of the above-identified embodiments will be obvious to one of ordinary skill in the art in view of the foregoing description. Accordingly, the invention is not to be limited by those specific embodiments of the anchor of the present invention shown and described herein. Rather, the scope of the invention is to be defined by the following claims and their equivalents.