Gastrointestinal implant with duodenal bulb anchor

Abstract

A gastrointestinal implant comprising a stent adapted to be positioned distal to a pyloric sphincter, within a superior duodenum of a patient, and having non-point spring elements for contacting an inner surface of the superior duodenum. A lumen of a flexible sleeve coupled to the stent receives food from the stomach and allows it to pass through the sleeve lumen without contacting gastrointestinal tissue adjacent to the sleeve. The stent may be sized to fit securely in the superior duodenum without proximal or distal migration.

Description

PATENTATTORNEY DOCKET NO.: 51148-050W02GASTROINTESTINAL IMPLANT WITH DUODENAL BULB ANCHORBackground of the Invention

[0001] Obesity is a significant and worsening health problem. Over thirty percent of the United States adult population is overweight (body mass index between 25 and 29.9), a group exceeding 100 million adults. An additional 42 percent, over 140 million, are obese (body mass index of 30 or higher), with a further nine percent (over 30 million) considered severely obese.

[0002] Excess body weight places strain on bones and joints, and adversely impacts major body organs and the nervous and circulatory systems. The World Health Organization estimates that about 2.8 millions deaths per year are directly related to obesity, and the US Centers for Disease Control and Prevention (CDC) estimates that 300,000 such deaths occur in the United States. Annual obesity healthcare costs in the US exceed $50 billion. Despite the toll in health suffering and financial cost associated with obesity, the prevalence of continues to increase not on the in the US but worldwide.

[0003] Co-morbidities associated with obesity is one of the principal costs to the healthcare system stems from co-morbidities associated with obesity. This includes Type- 2 diabetes, which recent data shows afflicts about 12% of the adult US population, as almost half of this group are clinically obese. Related co-morbidities of obesity include hypertension, coronary artery disease, hypercholesteremia, sleep apnea and pulmonary hypertension.

[0004] While the cause of obesity — an excess intake of calories relative to energy expended — is simple, the physiology and psychology of obesity are complex, and a reliable cure for obesity has proven elusive despite significant public and private investments. Once an individual’s BMI exceeds 30, significant lifestyle changes are usually required to meaningfully improve health status.

[0005] Surgical methods to address obesity have been explored in a variety of procedures to modify the anatomy to reduce food consumption. These include stapling of the stomach, or gastroplasty, which were widely performed in the 1980s and early 1990s to reduce the volume of the stomach and achieve a faster sensation of satiety. Although many patients achieved initial weight loss, obtaining sustained weight reduction remained elusive. Although the reasons are not fully known, one cause involved the stretching of surgically-reduced stomach over time. In addition, the psychological desire for food among some patients led many to regain weight despite the smaller pouch.PATENTATTORNEY DOCKET NO.: 51148-050W02

[0006] More recent surgical procedures with greater success in achieving long-term weight loss include Roux-en-Y gastric bypass and the biliopancreatic diversion with duodenal switch (BPD). Both Roux-en-Y and BPD procedures reduce the size of the stomach and shorten the effective-length of intestine available for nutrient absorption. By reducing the stomach size, both procedures limit the ability of the patient to take in food. In addition, both are malabsorptive in that bypassing the duodenum makes it more difficult to digest fats, high sugar and carbohydrate rich foods, thereby inducing weight loss. Both surgeries provide feedback to the patient by producing a dumping syndrome if they do eat high fat or carbohydrate food sources. Dumping occurs when carbohydrates directly enter the jejunum without being first conditioned in the duodenum, resulting in a significant discharge of fluid from the intestinal lining into the partially digested food, which can leave the patient light-headed and with severe diarrhea. For reasons that have not been determined, the procedures have immediate therapeutic effect on diabetes.

[0007] Though well-established surgically, the exact mechanism of action in these procedures is poorly understood. Current theory is that negative feedback is provided from both regurgitation into the esophagus and dumping when large volumes of certain foods are eaten. Eventually, patients learn that to avoid both these issues they must be compliant with the dietary restrictions imposed by the modified anatomy. In the BPD procedure, the stomach is not reduced in size as much as in Roux-en-Y procedures, so the patient is able to consume sufficient quantities of food to compensate for the reduced absorption. However, because more of the upper intestinal tract is bypassed, BPD can have serious side effects because of the significant malabsorption, and is reserved for the most morbidly obese patients.

[0008] Surgical treatments for obesity have significant risks of complications, with ten percent or more of patients requiring surgical intervention after the initial surgery. Early small bowel obstruction occurs in 2-6% in these surgeries, and mortality rates are reported to be approximately 0.5-1 .5%. While many patients successfully lose weight and maintain at least some of the weight loss over time, there is a need for less invasive procedures with lower rates of complications. Laparoscopic techniques in these surgeries provide some reduction in complications, but they continue to have relatively high rates of complications and demand a high level of surgical skill.

[0009] Devices to reduce absorption in the small intestines have been proposed (See U.S. Pat. No. 5,820,584 (Crabb), U.S. Pat. No. 5,306,300 (Berry) and U.S. Pat. No. 4,315,509 (Smit)). However, these devices have not been successfully implemented.PATENTATTORNEY DOCKET NO.: 51148-050W02

[0010] There is a need for improved devices and procedures for improved treatment of obesity which are less invasive than existing surgeries, provide a reduced risk profile, and are reversible.Summary of the Invention

[0011] The present invention provides a method and apparatus to limit absorption of food products in specific parts of the digestive tract using a barrier sleeve adapted to be positioned distal to the pyloric sphincter and providing reduced trauma to the patient while retaining natural stomach emptying.

[0012] In one embodiment, the invention provides a gastrointestinal implant comprising a stent adapted to be positioned distal to a pyloric sphincter, within a duodenal bulb of a patient, and having non-point spring elements for contacting an inner surface of the duodenal bulb. A lumen of a flexible sleeve coupled to the stent receives food from the stomach and allows it to pass through the sleeve lumen without contacting gastrointestinal tissue adjacent to the sleeve. The stent may be sized to fit securely in the duodenal bulb without proximal or distal migration. In some embodiments, the gastrointestinal implant may be delivered endoscopically through the mouth, throat, esophagus, and stomach using a delivery catheter, which preferably is adapted for passage through the gastrointestinal (Gl) tract without causing trauma.

[0013] In one embodiment, the invention provides a gastrointestinal implant system comprising: a) a collapsible stent adapted to be positioned in a superior duodenum distal to a pyloric sphincter and proximal to the superior flexure, and having a proximal stent end, a distal stent end, and a stent body comprising one or more struts defining a stent lumen, the stent comprising: 1 ) a first anchor comprising one or more spring structures extending radially outward from the stent body and defining a portion of the periphery of the stent, the first anchor being located nearer to the proximal stent end than the distal stent end and having one or more curved contact surfaces adapted to non-penetratingly contact a first wall portion of the superior duodenum and to exert a first radial force on said first wall portion; and 2) a second anchor comprising one or more spring structures extending radially outward from the stent body and defining a portion of the periphery of the stent, the second anchor being distal to the first anchor and having one or more curved contact surfaces adapted to non-penetratingly contact a second wall portion of the superior duodenum distal to the first wall portion, and to exert a second radial force on said second wall portion; and b) a flexible sleeve having a proximal sleeve end adapted to be coupled to the collapsible stent, a central portionPATENTATTORNEY DOCKET NO.: 51148-050W02 defining a sleeve lumen extending at least partially through the stent lumen, and a distal sleeve end, the central portion adapted to extend a defined length into at least one of the duodenum, the jejunum, and the ileum.

[0014] In one embodiment, the invention comprises a gastrointestinal implant system comprising: a) a stent adapted to be configured by a user in one of a collapsed position and an expanded position and having a proximal stent end adapted to contact a first patient gastrointestinal structure located distal to a pyloric sphincter, a distal stent end adapted to contact a second patient gastrointestinal structure distal to the first patient gastrointestinal structure, and a stent body comprising one or more struts having a plurality of turns defining a stent lumen having a lumen axis, and tapering from a first dimension generally perpendicular to said lumen axis at the proximal stent end to a second dimension generally perpendicular to the lumen axis at the distal stent end; and b) a flexible sleeve having a proximal sleeve end adapted to be coupled to the collapsible stent, a central portion defining a sleeve extending at least partially through the stent lumen, and a distal sleeve end, the center portion adapted to extend a defined length into the duodenum.

[0015] The flexible sleeve is open at both ends and adapted to extend into the duodenum to limit absorption of nutrients therein. The sleeve may be impregnated with an antihunger hormone such as peptide-YY, or with one or more drugs to reduces inflammation or infection risk. In some embodiments, the sleeve comprises low friction materials such as cast polytetrafluoroethylene, polytetrafluoroethylene, cast fluorinated ethylene propylene with polytetrafluoroethylene coating, extruded fluorinated ethylene propylene and extruded perfluoroalkoxy.Brief Description of the Drawings

[0016] The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale; emphasis instead is placed upon illustrating the principles of the invention.

[0017] As used herein, the term “non-penetrating stent” refers to a stent that is capable of contacting the body of a patient without causing entry of any portion of the stent beyond the surface of the body portion being contacted. The term precludes not only having a portion passing completely through a wall of a body portion, such as a wall of a superior duodenum, but also causing a partial entry into the body portion without completelyPATENTATTORNEY DOCKET NO.: 51148-050W02 penetrating or piercing the same. Accordingly, a “non-penetrating” stent lacks any barb, point, or sharp edge intended to penetrate the contacted body portion partially or completely. The term does not preclude a roughened, non-penetrating surface capable of allowing ingrowth of tissue (e.g., epithelial cells) into the outer surface of the stent.

[0018] FIG. 1 is a sectional view of a portion of a portion of the digestive tract of a human patient, showing the stomach, duodenum, and jejunum.

[0019] FIGS. 2A and 2B are perspective views of one embodiment of a non-penetrating stent for securing a gastrointestinal implant in a duodenal bulb of a human patient, in an expanded configuration (FIG. 2A) and a collapsed configuration (FIG. 2B).

[0020] FIG. 2C illustrates a gastric sleeve during a procedure coupling the sleeve to the stent of FIGS. 2A and 2B.

[0021] FIG. 2D depicts the gastric sleeve of FIG. 2C after coupling to the stent of FIGS. 2A and 2B.

[0022] FIG. 2E is a cross-sectional view of the stent of FIGS. 2A-2D.

[0023] FIGS. 3A and 3B are perspective views of another embodiment of a nonpenetrating stent for securing a gastrointestinal implant in a duodenal bulb of a human patient, in an expanded configuration (FIG. 2A) and a collapsed configuration (FIG. 2B).

[0024] FIG. 3C illustrates a gastric sleeve during a procedure coupling the sleeve to the stent of FIGS. 3A and 3B.

[0025] FIG. 3D shows the gastric sleeve of FIG. 3C after coupling to the stent of FIGS. 3A and 3B.

[0026] FIGS. 3E and 3F are perspective views of a further embodiment of additional embodiments of a non-penetrating stent for securing a gastrointestinal implant in a superior duodenum of a human patient.

[0027] FIG. 4A is a perspective view of another embodiment of a non-penetrating stent for securing a gastrointestinal implant in a duodenal bulb of a human patient, in an expanded configuration.

[0028] FIG. 4B is a top view of the stent of FIG. 4A.

[0029] FIG. 4C is a perspective view of the stent of FIGS. 4A and 4B in a collapsed configuration.

[0030] FIG. 5A is a perspective view of another embodiment of a non-penetrating stent for securing a gastrointestinal implant in a duodenal bulb of a human patient, in an expanded configuration.PATENTATTORNEY DOCKET NO.: 51148-050W02

[0031] FIG. 5B illustrates a gastric sleeve during a procedure coupling the sleeve to the stent of FIG. 5A.

[0032] FIG. 5C shows the gastric sleeve of FIG. 5B after coupling to the stent of FIGS. 5A and 5B.Detailed Description of the Invention

[0033] Exemplary embodiments of the present disclosure are illustrated in the drawings, which are illustrative rather than restrictive. No limitation on the scope of the technology or on the claims that follow is to be implied or inferred from the examples shown in the drawings and discussed here.

[0034] In some embodiments, the gastrointestinal sleeve includes an anchor portion and a floppy, flexible, thin, conformable, and / or collapsible sleeve portion. FIG. 1A is a sectional view of a portion of the digestive tract in a human patient. Food to be digested is introduced to the stomach 102 by through the cardiac orifice 1 10 from the esophagus by the dilation of the cardiac sphincter 1 1 1. The stomach 102 acts to partially digest food to produce chyme, a semi-fluid, homogeneous, gruel-like material, which exits the stomach through the pyloric orifice 108. The pyloric orifice 108 is a distal aperture of the stomach 102 surrounded by a strong band of circular muscle forming the pyloric sphincter 109. Chyme exits the stomach 102 via dilation of the pyloric sphincter 109, and passes into the duodenum, which is the first part of the small intestine. The small intestine is about 15-20 feet in length and comprises a convoluted tube extending from the pyloric orifice 108 to the ileocecal valve where it terminates in the large intestine. The small intestine has three sections, the duodenum, the jejunum 106, and the ileum (not shown in FIG. 1 ). The duodenum makes up the first 10-12 inch section of the small intestine and tends to be the shortest, widest, and most fixed part of the small intestine.

[0035] The duodenum has four sections which typically form a U shape: the superior duodenum 1 19, the descending duodenum 132, the horizontal duodenum 136, and ascending duodenum 126. The superior duodenum 1 19 is about two inches long and ends at the superior duodenal flexure 128. The superior duodenum 1 19 also defines a feature referred to as the duodenal bulb, which begins just distal to the pyloric sphincter 109 and extends about 1 to 1.5 inches in an adult human. While the duodenal bulb is sometimes described as comprising only a proximal, dilated portion of the superior duodenum 1 19, in the present disclosure the term “duodenal bulb” is used synonymously as the entire superior duodenum from immediately distal to the pyloric sphincter 109 to the superior duodenal flexure 128. The superior duodenum 1 19 defines a lumen thereinPATENTATTORNEY DOCKET NO.: 51148-050W02 that is slightly larger than the remaining portions of the duodenum, and has less motion than the pyloric sphincter 109 and the distal portions of the duodenum 132,136, 126. Notably, the motion of the superior duodenum 1 19 is substantially limited to radial contractions without having a significant linear component (i.e., no movement along the central axis of the intestine). The tissue of the intestinal wall of the pyloric sphincter 109 and the superior duodenum tends to be thicker than that of the remaining portions of the duodenum and other parts of the small of the small intestine.

[0036] The descending duodenum 132 is about three to four inches long and introduces includes circular tissue folds 138 also known as the valves of Kerckring, which are not present in the superior duodenum 1 19 but are found in the horizontal duodenum 136 and ascending duodenum 126. The descending duodenum 132 also includes a nipple-shaped structure, the papilla of Vater 1 14, through which pancreatic juice from the pancreas and bile (produced by the liver and stored by the gall bladder) enter the duodenum from the pancreatic and bile ducts. The pancreatic juice contains enzymes for protein digestion, and bile dissolves the products of fat digestion. The ascending section is about two inches long and ends at the duodenojejunal flexure 1 16 where it joins the jejunum 106, the next section of the small intestine. The duodenoejunal flexure 116 is fixed to the ligament of Treitz 1 18 (not shown in FIG. 1 ). The juices secreted into the duodenum break the partially digested food down into particles small enough to be absorbed by the body. Additional details are provided in Gray's Anatomy (“Anatomy of the Human Body,” by Henry Gray) and “Human Physiology,” Vander, 3rd ed, McGraw Hill, 1980.

[0037] This invention includes methods and devices for placing or implanting a gastrointestinal implant device in a mammal. For example, this invention includes methods and devices for implanting a gastrointestinal sleeve. In some embodiments, the gastrointestinal sleeve includes an anchor portion and a floppy, flexible, thin, conformable, and / or collapsible sleeve portion.

[0038] FIG. 2A is a perspective view of one embodiment of a collapsible stent 210 adapted to non-penetratingly secure a gastrointestinal implant in a superior duodenum 1 19 of a patient. The collapsible stent 210, shown in an expanded configuration in FIG. 2A, comprises a stent body 212 having a plurality of struts 218 defining a stent lumen, with a shape adapted to fit within the superior duodenum 1 19. In one embodiment, the stent body 212 is generally tubular or cylindroid in shape and defines a stent lumen having a central axis 21 1. In the embodiment of FIG. 2A, the stent 210 is generally barrel or fusiform in shape, while in other embodiments the stent may have a right cylindricalPATENTATTORNEY DOCKET NO.: 51148-050W02 shape, a tapering cylindrical shape, or other tubular shapes (e.g., a corrugated tubular shape). The stent 210 includes a proximal end 214 adapted to be located in the superior duodenum 1 19 at a location near but distal to the pyloric sphincter 109, and a distal end 216 adapted to be located in the superior duodenum near but proximal to the superior duodenal flexure 128. In an alternative embodiment (not shown), distal end 216 may extend beyond the superior duodenal flexure 128 and into the descending duodenum 132.

[0039] The stent 210 further comprises a plurality of non-penetrating anchors 220, 222, 224, adapted to contact an interior wall of the superior duodenum 1 19. As used herein, “non-penetrating” refers to structures lacking barbs, spikes, prongs, or other sharp or pointed structures adapted to provide contact to puncture or penetrate tissue. Instead, non-penetrating structures are those which provide a contact surface that is not adapted to penetrate tissue. A first anchor 220 is located nearer to the proximal end 214 of stent 210 than to the distal end 216. A second anchor 222 is located distal to the first anchor 220 near the middle of the stent body, and a third anchor 224 is located distal to the second anchor 222 and near the distal end 216. In the embodiment of FIGS. 2A-2E, the anchors 220, 222, 224 each comprise a broken ring formed of a plurality of ring segments. Each of the segmented ring anchors 220, 222, 224 is positioned generally transverse to the axis 21 1 of the stent body 212. Each ring segment of anchors 220, 222, and 224 extends radially outward from the stent body 212 and has curved or rolled outer surfaces adapted to non-penetratingly engage a portion of the wall of the superior duodenum 1 19 at selected locations along its length between the pyloric sphincter 109 and the superior duodenal flexure 128. Each ring segment is a spring element adapted to exert a radial force on the outer duodenum wall in contact with the ring segment stent 210 is when positioned in the superior duodenum 1 19. As shown in FIG. 2E, each ring segment 220, 222, 224 comprises a spiral cross-section with an opening 221 , 223, 225 facing toward the distal end 216 of the stent 210.

[0040] Because the ring segment openings 221 , 223, 225 face toward the distal end 216 of the stent 210, movement of the gastrointestinal implant in a distal direction of the patient’s Gl tract will result in a proximally directed force F of the Gl tissue on the outer edges of the ring segments 220, 222, 224, as shown in FIG. 2C. Proximally-directed force F will tend to unfurl or open the spiral shape of each segment of anchors 220, 222, 224, which will in turn cause an opposing resistive force on the tissue as each spring segment of anchors 220, 222, 224 resists force F. Conversely, proximal movement of the implantPATENTATTORNEY DOCKET NO.: 51148-050W02 will result in a force G acting distally (i.e., opposite to force F) that will tend to compress or close the spirally shaped spring segments, which will also generate an opposing proximal spring force on the Gl tissue by spring anchors 220, 222, 224, but less than the force resisting force F acting in the opposite direction to the spiral openings. Accordingly, the distally-opening anchors 220, 222, 224 shown in FIGS. 2A-2E will resist distal movement and migration more than proximal movement. In an alternative embodiment (not shown), the segments of anchors 220, 222, 224 may comprise proximally-facing spiral openings, which will resist proximal movement more than distal movement. In a still further alternative embodiment (not shown) the segments of anchors 220, 222, 224 may comprise a mixture of both proximally-facing openings and distally-facing openings, each providing greater resistance to distal movement (in the case of distally-facing openings) or proximal movement (in the case of proximally-facing spiral openings). As shown in FIGS. 2A and 2B, three anchor elements 220, 222, and 224 are provided. In alternative embodiments, two, four, or more anchor elements may be provided, and each anchor element may have a circumference or diameter selected to securely position the Gl device in the superior duodenum with no or minimal migration.

[0041] FIG. 2B shows the stent 210 of FIG. 2A in a collapsed configuration. The stent body 212 is shown collapsed into a smaller radial diameter, and the broken ring elements of anchors 220, 222, and 224 are folded down the outside of the stent 219 toward the distal end 216. In this configuration, the stent (and a sleeve 250 as shown in FIG. 2C) may be coupled to a catheter or other delivery system for delivering the gastrointestinal implant to a deployment location distal to the pyloric sphincter 109.

[0042] FIG. 2C illustrates a gastrointestinal implant 200 comprising the stent 210 of FIGS. 2A and 2B, and a flexible sleeve 250. The Gl implant 200 is shown during a procedure coupling the sleeve 250 to the stent 210 of FIG. 2A. The sleeve 250 includes a proximal portion 252 adapted to fold down to cover at least a portion of the stent body 210. The sleeve proximal portion 252 includes a proximal end 254 and apertures or windows 256 adapted to allow the spring elements of anchors 220, 222, and 224 to extend through the windows to engage the wall surfaces of the superior duodenum 1 19. Sleeve 250 also includes a distal portion 258 and a distal end 260. Distal portion 258 of the sleeve extends into at least one of the duodenum, jejunum and / or ileum to prevent the absorption of food. In addition, a tapered or narrowing section 262 is provided to accommodate a decrease in the inside diameter of sleeve 250, which in turn accommodates a narrowing of the anatomy from the superior duodenum 1 19 into the descending duodenum, horizontalPATENTATTORNEY DOCKET NO.: 51148-050W02 duodenum, ascending duodenum, and jejunum. In alternative embodiments, a constant diameter may be used, or the diameter may vary along its length depending on the anatomy of the patient.

[0043] FIG. 2D illustrates the gastrointestinal implant 200 after the coupling procedure shown in FIG. 2C is completed. In the embodiment shown, proximal portion 252 has been folded down over stent body 212 and sealed at a location 230 to a portion of the sleeve distal to the distal end 216 of the stent 210. In the embodiment shown, proximal portion 252 of sleeve 250 covers substantially all of the stent body 212 while windows 256 allow the spring elements of anchors 220, 225, and 224 to extend radially outward from the stent body to engage a wall of the superior duodenum 1 19. Although FIG. 2D is shown with the stent body 212 substantially completely covered by the proximal portion 252 of sleeve 250, in alternative embodiments some or all of the stent body may remain exposed or uncovered by the sleeve.

[0044] FIGS. 3A-3F illustrate other embodiments of a Gl implant device 300 including a collapsible stent 310 for non-penetrating contact with a wall of a superior duodenum 1 19, with a flexible sleeve 350 coupled to the stent to transport chyme from the pyloric sphincter through a portion of the Gl tract to avoid food absorption in the Gl tract adjacent to the sleeve. The implant of FIGS. 3A-3D is similar to that FIG. 2A, except that the anchor elements comprise a series of individual wire or wire-like spring elements that together form a ring structure, instead of discrete ring segments as in FIG. 2A.

[0045] FIG. 3A is a perspective view of the stent 310, adapted to non-penetratingly secure the Gl implant device 300 (FIG. 3C) in a superior duodenum of a patient. Shown in an expanded configuration, the collapsible stent 310 comprises a stent body 312 having a plurality of struts 318 defining a stent lumen. The shape of the stent 310 is adapted to fit within the superior duodenum 1 19 without proximal or distal migration. The stent body 312 is generally tubular or cylindroid in shape and defines a stent lumen having a central axis 31 1 . In the embodiment of FIG. 3A, the stent is generally barrel or fusiform in shape, while in other embodiments the stent may have a right cylindrical shape, a tapering cylindrical shape, or other tubular shapes (e.g., a corrugated tube). The stent 310 includes a proximal end 314 adapted to be located in the superior duodenum 1 19 at a location near but distal to the pyloric sphincter 109, and a distal end 316 adapted to be located in the superior duodenum near but proximal to the superior duodenal flexure. In an alternative embodiment (not shown), distal end 316 may extend beyond the superior duodenal flexure 128 and into the descending duodenum 132. In a still furtherPATENTATTORNEY DOCKET NO.: 51148-050W02 embodiment, proximal end 314 may be adapted for implantation into a portion of the Gl tract of the patient distal to the superior duodenum, such as the descending duodenum 132, the horizontal duodenum 136, the ascending duodenum 126, or the jejunum 106 of the patient.

[0046] Stent 310 comprises a plurality of non-penetrating anchors adapted to contact an interior wall of the superior duodenum 1 19 at locations along its length. A first anchor 320 is located nearer to the proximal end 314 than to the distal end 316. A second anchor 322 is located distal to the first anchor 320 near the middle of the stent body, and a third anchor 324 is located distal to the second anchor 322, near distal end 316. Each of the anchors 320, 322, 324 comprises a series of wire or wire-like spring elements that together comprise a generally planar ring structure positioned generally transverse to the axis 31 1 of the stent body 312. While different numbers of wire elements may be provided to comprise each generally planar anchor 320, 322, 324, it will be appreciated that a greater number of wire elements for a particular anchor will distribute the spring force exerted by the anchors to a larger area and contribute to greater stability, while fewer wire elements for a given anchor will facilitate easier fabrication. As shown in FIG. 3A, each wire spring element extends radially outward from the stent body 312 and has a curved and / or spiral configuration adapted to non-penetratingly engage a portion of the wall of the superior duodenum 119 at selected locations, and to exert a radial spring force at its location. Each wire spring element of anchors 320, 322, 324 also comprise a distally- facing opening 321 , 323, 325 (FIG. 3C). In the embodiments illustrated in FIGS. 3A-3D, anchor elements are shown at three generally planar locations along the length of the stent. It will be appreciated in view of the present disclosure that different numbers of anchors may be used, provided at least two such anchors are provided. In still another embodiment, a plurality of wirelike structures may be distributed evenly or randomly throughout the length of the stent body, rather than at particular planar locations.

[0047] FIG. 3B shows the stent 310 of FIG. 3A in a collapsed configuration. The stent body 312 is shown collapsed into a smaller radial diameter than in FIG. 3B, and the spring wire anchors 320, 322, and 324 may be folded partially downward against the stent body 312. In the collapsed configuration, the stent 310 (and sleeve 350, FIGS. 3C and 3D) may be coupled to a catheter or other delivery system for delivering the gastrointestinal implant to a deployment location distal to the pyloric sphincter 109.

[0048] FIG. 3C illustrates a gastrointestinal implant 300 comprising the stent 310 of FIGS. 3A and 2B and a flexible sleeve 350. The implant 300 is shown prior to the coupling ofPATENTATTORNEY DOCKET NO.: 51148-050W02 the sleeve 350 to the stent 310. The sleeve 350 includes a proximal portion 352 adapted to fold down to cover at least a portion of the stent body 310. The sleeve proximal portion 352 includes a proximal end 354 and slits or apertures 356 adapted to allow the wire spring elements of anchors 320, 322, and 324 to extend through the slits when the proximal portion 350 is folded down to cover the stent body. Because the spring elements extend through slits 356, they are adapted when implanted to engage the wall surfaces of the superior duodenum 119. Sleeve 350 also includes a distal portion 358 and a distal end 360. Distal portion 358 extends into at least one of the duodenum, jejunum and / or ileum to prevent the absorption of food until it exits the sleeve lower in the Gl tract. A tapered or narrowing section 362 is shown as the diameter of sleeve 350 narrows to accommodate a narrowing of the anatomy from the superior duodenum 1 19 into more distal portions of the Gl tract. In alternative embodiments, a constant diameter may be used, or the diameter may change along the length of the sleeve 350 to better comply with the anatomy of the patient.

[0049] Because the openings 321 , 323, 325 of each wire element of anchors 320, 322, 324 shown in FIGS. 3A-3D face toward the distal end 316 of the stent 310, movement of the gastrointestinal implant in a distal direction of the patient’s Gl tract will result in a proximally directed force F of the Gl tissue on the outer edges of each wire element, as shown in FIG. 3C. Proximally-directed force F will tend to unfurl or open the spiral shape of each wire element of anchors 320, 322, 324, which will in turn cause an opposing resistive force on the tissue as each wire element of anchors 320, 322, 324 resists force F. Conversely, proximal movement of the implant will result in a force G acting distally (i.e., opposite to force F) that will tend to compress or close the spirally shaped spring wire elements, which will also generate an opposing proximal spring force on the Gl tissue by the spring wire elements, but less than the force resisting force F acting in the opposite direction to the spiral openings. Accordingly, the distally-opening wire elements shown in FIGS. 3A-3D will resist distal movement and migration more than proximal movement.

[0050] In an alternative embodiment shown if FIG. 3E, the wire spring elements of one of the anchors 322 may comprise proximally-facing spiral openings, which will resist proximal movement more than distal movement. In a still further alternative embodiment shown in FIG. 3F, the spring wire elements of anchors 320, 322, 324 may comprise a mixture of both proximally-facing openings and distally-facing openings, each providing greater resistance to distal movement (in the case of distally-facing openings) or proximal movement (in the case of proximally-facing spiral openings). In FIGS. 3A-3F, threePATENTATTORNEY DOCKET NO.: 51148-050W02 distinct rows of ring anchors 320, 322, and 324 (each comprising a plurality of wire elements) are provided. In alternative embodiments, two, four, or more generally planar anchor elements may be provided, and each anchor element may have a circumference or diameter selected to securely position the Gl device in the superior duodenum with no or minimal migration. In a still further embodiment (not shown) spring wire elements may be distributed evenly or randomly both radially and longitudinally along the stent body 312, and may comprise distally facing openings, proximally facing openings, or a mixture of proximally-facing and distally-facing openings.

[0051] FIG. 3D illustrates the gastrointestinal implant 300 after the coupling procedure shown in FIG. 3C is completed. In the embodiment shown, proximal portion 352 has been folded down over stent body 312 and sealed at a location 330 to a portion of the sleeve 350 distal to the distal end 316 of stent 310. As shown, proximal portion 352 covers substantially all of the stent body 312 while slits 356 allow the wire spring elements of anchors 320, 322, and 324 to extend radially outward from the stent body to engage a wall of the superior duodenum. Although FIG. 3D is shown with the stent body 312 substantially completely covered by the proximal portion 352 of sleeve 350, in alternative embodiments some or all of the stent body may remain exposed or uncovered by the sleeve.

[0052] FIG. 4A illustrates a further embodiment of a collapsible stent 410 for a Gl implant device for non-penetrating positioning within a superior duodenum. Stent 410, shown in an expanded configuration, comprises a series of generally planar rings 420 together forming a stent lumen. Rings 420 are joined by a plurality of struts 430 generally parallel to a central axis 41 1 of the stent 410, which includes a proximal end 412 and a distal end 414. The stent 410 shaped or sized to fit within the superior duodenum 1 19. In the embodiment of FIG. 4A, the stent 410 is barrel-shaped, although in alternative embodiments (not shown) the stent may have a right cylindrical shape, a tapering cylindrical shape, or other tubular forms. FIG. 4B is a top plan view showing the stent 410 of FIG. 4A, including rings 420 and connecting struts 430. The diameter of each ring 420 along the length of the stent 410 may be selected to closely conform to an anatomy of the superior duodenum 1 19.

[0053] FIG. 4C shows the stent 410 in a collapsed position. In the embodiment shown, three axially-oriented struts are provided, and the stent may be collapsed along the axis of one of the struts by pivoting the rings along the axis of the strut, causing the segments of the other struts to bow outwardly (or inwardly). FIG. 4C illustrates one embodiment ofPATENTATTORNEY DOCKET NO.: 51148-050W02 how the stent 410 may be moved to a collapsed position. Other modes of collapsing the stent may be appreciated by persons of skill in the art in view of the teachings and disclosure provided herein. It will also be appreciated that different number of rings and struts, and different ring diameters and strut lengths, may be used to provide a close anatomical fit to the superior duodenum for a wide variety of patients.

[0054] FIGS. 5A-5C illustrate another embodiment of a Gl implant device 500 including a collapsible spiral coil stent 510 for non-penetrating contact with a wall of a superior duodenum 119, and a flexible sleeve 550 coupled to the stent to transport chyme from the pyloric sphincter through a portion of the Gl tract to avoid food absorption in at least a portion of the duodenum, jejunum, and / or ileum. The implant device of FIGS. 5A-5C is similar to that FIGS. 2A-2C, except that stent 510 comprises a spiral spring coil shape.

[0055] FIG. 5A illustrates a collapsible spiral coil stent 510 adapted to non-penetratingly secure a gastrointestinal implant in a superior duodenum 1 19. The spiral coil stent 510 is shown in an expanded configuration in FIG. 5A, and comprises a wire comprising a spiral coil spring having a lumen with a central axis 51 1 , a proximal stent end 514, a distal stent end 524, and a plurality of turns 512 defining the stent lumen. While the spiral coil stent 510 is shown as having a generally barrel shape, in alternative embodiments different spiral coil shapes (e.g., a right cylinder, etc.) may be used. At proximal stent end 514, at least one initial turn of the spiral coil stent 510 provides a general planar proximal ring having a radius of curvature defining a first radial dimension (e.g., a diameter). In more distal coil turns, the distance between the adjacent turns of the coil is larger, and at distal end 524 a generally planar distal ring is provided. In distal turns, the radius of curvature may vary to provide varying radial coil dimensions (e.g., a varying coil stent diameter). The number of turns, the radius of each turn, and the distance between adjacent turns may be selected to size the spiral coil stent 510 to provide a secure, non-penetrating fit within at least a portion of the superior duodenum 1 19. A bead or enlarged diameter element 516 may be provided in one embodiment to help secure a sleeve 550 to the spiral coil stent 510.

[0056] In one embodiment, the length of the spiral coil stent 510 is sized to allow the stent to be compressed slightly along the central axis from a first length L1 to a second, shorter length L2 to provide a spring force acting along the longitudinal axis of the superior duodenum 119 to retain the Gl implant device 500 in a desired location in the superior duodenum with minimal or no proximal or distal migration. A first spring force at the proximal stent end 514 of the spiral coil stent 510 may be applied to one or more of aPATENTATTORNEY DOCKET NO.: 51148-050W02 distal surface of the pyloric sphincter 109 and a proximal surface of the superior duodenum 1 19, while a second spring force at the distal stent end 524 of the stent may be applied to one or more of a portion of the superior duodenal flexure and a distal surface of the superior duodenum. In alternative embodiments, the spring force at the distal end may be applied to a proximal or distal surface of the descending duodenum. The first and second spring forces have a magnitude of at least 0.5 N, and may vary in magnitude based on peristalsis occurring within the duodenum.

[0057] FIG. 5B is a side view of a gastrointestinal implant 500 comprising the spiral coil stent 510 of FIG. 5A. The implant is shown during a procedure to couple the spiral coil stent 510 to the flexible sleeve 550, which includes a proximal portion 552 adapted to be folded down over at least the proximal stent end 514 of the spiral coil stent 510. The sleeve proximal portion 552 includes a proximal sleeve end 554 and an aperture or hole 556 to capture bead 516 within a fold or hem when the proximal sleeve end is folded down over at least a portion of the proximal stent end 514, as shown more clearly in FIG. 5C. Flexible sleeve 550 also includes a distal portion 558 including a distal end 560 from which food exits the sleeve into the lower portions of the Gl tract. A tapered or narrowing section 562 may provide a transition from a larger diameter of flexible sleeve 550 within the superior duodenum 1 19 to a narrower diameter in distal portion 560 to accommodate a narrowing of the anatomy from the superior duodenum 1 19 into more distal portions of the Gl tract. In alternative embodiments, a constant or varying diameter may be used.

[0058] FIG. 5C illustrates the gastrointestinal implant 500 after the coupling procedure shown in FIG. 5B is completed. In the embodiment shown, proximal portion 552 of flexible sleeve 550 has been folded down and sealed at a seal or hem 558 to cover substantially only the generally planar first turn at the proximal stent end 514 of spiral coil stent 510. Bead 516 is sized to be larger than aperture or hole 556 in proximal portion 552 of flexible sleeve 550, and thus may be used to prevent the sleeve and stent from separating by rotation, such that the generally planar first turn rotates sufficiently to pass through aperture 556, decoupling the spiral coil stent 510 from the flexible sleeve. When the proximal end 514 of spiral coil stent 510 is captured along with bead 516 within the hem or seal 558 of the proximal portion 552 of flexible sleeve 550, any portion of the stent proximal to the captured bead is prevented from passing through aperture 556. Although FIG. 5C is shown with substantially only the planar first turn of the proximal end covered by the proximal portion 552 of sleeve 550, in alternative embodiments additional portionsPATENTATTORNEY DOCKET NO.: 51148-050W02 or all of the stent body 512 may be covered by proximal portion 552 of the sleeve 550 within seal 558.

[0059] The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Embodiments of the present invention disclosed and claimed herein may be made and executed without undue experimentation with the benefit of the present disclosure. While the invention has been described in terms of particular embodiments, it will be apparent to those of skill in the art that variations may be applied to systems and apparatus described herein without departing from the concept, spirit and scope of the invention. Examples are all intended to be non-limiting. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention, which are limited only by the scope of the claims.

Claims

PATENTATTORNEY DOCKET NO.: 51148-050W02CLAIMS1 . A gastrointestinal implant system comprising: a) a collapsible stent adapted to be positioned in a superior duodenum distal to a pyloric sphincter and proximal to the superior flexure, and having a proximal stent end, a distal stent end, and a stent body comprising one or more struts defining a stent lumen, the stent comprising:1 ) a first anchor comprising one or more spring structures extending radially outward from the stent body and defining a portion of the periphery of the stent, the first anchor being located nearer to the proximal stent end than the distal stent end and having one or more curved contact surfaces adapted to non- penetratingly contact a first wall portion of the superior duodenum and to exert a first radial force on said first wall portion; and2) a second anchor comprising one or more spring structures extending radially outward from the stent body and defining a portion of the periphery of the stent, the second anchor being distal to the first anchor and having one or more curved contact surfaces adapted to non-penetratingly contact a second wall portion of the superior duodenum distal to the first wall portion, and to exert a second radial force on said second wall portion; and b) a flexible sleeve having a proximal sleeve end adapted to be coupled to the collapsible stent, a central portion defining a sleeve lumen extending at least partially through the stent lumen, and a distal sleeve end, the central portion adapted to extend a defined length into at least one of the duodenum, the jejunum, and the ileum.

2. The gastrointestinal implant system of claim 1 , wherein the first anchor is adapted to provide non-penetrating contact with the first wall portion, and the second anchor is adapted to provide non-penetrating contact with the second wall portion.

3. The gastrointestinal implant system of claim 1 , wherein the first anchor and the second anchor are adapted to prevent migration of the collapsible stent from the superior duodenum.PATENTATTORNEY DOCKET NO.: 51148-050W024. The gastrointestinal implant system of claim 1 , wherein the first anchor and the second anchor each comprise one of a continuous annular ring and a broken annular ring.

5. The gastrointestinal implant system of claim 1 , wherein and least one of the first anchor and the second anchor are selected based on an identified dimension of the first wall portion and the second wall portion of the patient.

6. The gastrointestinal implant system of claim 1 , wherein at least one of the first anchor and the second anchor are sized to exert a radial force within a range of 0.75-1 .25 N against at least one of the first wall portion and the second wall portion.

7. The gastrointestinal implant system of claim 1 , further comprising a flexible cord adapted to be engaged by a user to place the stent in one of a collapsed configuration and an expanded configuration.

8. The gastrointestinal implant system of claim 1 , further comprising a deployment system for the collapsible stent and flexible sleeve, comprising:1 ) a first conduit having a proximal end and a distal end adapted for insertion through the patient’s mouth, esophagus, and stomach to a deployment location in the patient’s superior duodenum;2) a stent delivery sheath having a proximal end and a distal end adapted to retain the collapsible stent in a collapsed position for delivery to the deployment location, wherein the stent delivery sheath is adapted for insertion into the first conduit and is capable of being manipulated by a user to cause the deployment of the collapsible stent from a collapsed position to an expanded position in contact with the first wall portion and the second wall portion; and3) a sleeve delivery sheath having a proximal end and a distal end adapted to retain the flexible sleeve in a first position for delivery to the deployment location, wherein the sleeve delivery sheath is adapted for insertion into the first conduit and is capable of being manipulated by a user to couple the proximal sleeve end to the proximal stent end.PATENTATTORNEY DOCKET NO.: 51148-050W029. The gastrointestinal system of claim 8, further comprising a removal system for the collapsible stent and flexible sleeve, comprising:1 ) a stent removal sheath having a proximal end and a distal end, and comprising:A) a cone-shaped element having a narrow proximal end and a wider distal end adapted to receive the proximal stent end; andB) a grasping element adapted to contact at least a portion of the proximal stent end to pull the stent into the wider distal end of the cone-shaped element to contact an inner surface of the cone-shaped element and place the proximal stent end into at least a partially collapsed position for removal from the patient’s gastrointestinal system.

10. The gastrointestinal implant system of claim 9, wherein the proximal stent end comprises a flexible cord coupled to the proximal stent end, and the grasping element comprises a hook adapted to be manipulated by a user to grasp the flexible cord and pull the stent into the wider distal end of the cone-shaped element.11 . The gastrointestinal implant system of claim 1 , at least a portion of the stent body is coated with a first material selected to facilitate tissue ingrowth into the first material.

12. The gastrointestinal implant system of claim 11 , wherein the first material is selected from at least one of a polyethylene glycol (PEG) polymer and hydroxyapatite.

13. The gastrointestinal implant system of claim 11 , wherein at least a portion of the stent body is not coated with the first material and is coated with a contrast indicator selected to improve visibility in at least one imaging procedure.

14. The gastrointestinal implant system of claim 1 , further comprising a locking ring for coupling the proximal sleeve end to the proximal stent end of the collapsible stent, the locking ring adapted to ensure that all stomach contents pass through the flexible sleeve and prevent stomach contents from passing through the patient’s gastrointestinal system without passing through the flexible sleeve.

15. A gastrointestinal implant system comprising:PATENTATTORNEY DOCKET NO.: 51148-050W02 a) a collapsible spiral coil stent adapted to be configured by a user in one of a collapsed position and an expanded position and having:1 ) a proximal stent end adapted to contact a first patient gastrointestinal structure in a superior duodenum;2) a distal stent end adapted to contact a second patient gastrointestinal structure distal to the first patient gastrointestinal structure; and3) a stent body comprising a spiral coil shape having a plurality of turns defining a stent lumen having a lumen axis; and b) a flexible sleeve having a proximal sleeve end adapted to be coupled to the collapsible spiral coil stent, a central portion defining a sleeve extending at least partially through the stent lumen, and a distal sleeve end, the central portion adapted to extend a defined length into at least one of the duodenum, the jejunum, and the ileum of the patient.

16. The gastrointestinal implant system of claim 15, wherein the collapsible spiral coil is adapted to be compressed from a first length to a second length to retain the gastrointestinal implant system within a desired location in the superior duodenum of the patient.

17. The gastrointestinal implant system of claim 16, wherein the proximal stent end is adapted to apply a spring force to one or more of a distal surface of a pyloric sphincter and a proximal surface of the superior duodenum, and the distal end is adapted to apply a spring force to one or more of a portion of the superior duodenal flexure and a distal surface of the superior duodenum.

18. The gastrointestinal implant system of claim 15, wherein the collapsible spiral stent further comprises a generally planar proximal ring having a bead; and the flexible sleeve proximal end comprises a folded portion having a seal adapted to capture the bead and at least a portion of the generally planar proximal ring within the folded portion.

19. The gastrointestinal implant system of claim 15, wherein the collapsible spiral stent comprises a first radial dimension at the proximal stent end, and at least one secondPATENTATTORNEY DOCKET NO.: 51148-050W02 radial dimension different from the first radial dimension at a distal location along the axis of the coil.

20. The gastrointestinal implant system of claim 15, wherein the collapsible stent further comprises a number of turns each having at least one radius of curvature and a distance between an adjacent turn, and wherein at least one of the number of turns, the at least one radius of curvature, and the distance between an adjacent turn is selected to retain the gastrointestinal implant system within a desired location within the duodenum of the patient.21 . The gastrointestinal implant system of claim 15, wherein the proximal stent end is adapted to apply a first spring force of at least 0.5 N to one or more of a distal surface of a pyloric sphincter and a proximal surface of the superior duodenum; and the distal end is adapted to apply a second spring force of at least 0.5 N to one or more of a portion of the superior duodenal flexure and a distal surface of the superior duodenum; and wherein the first and second spring forces vary in magnitude based on peristalsis occurring within the duodenum of the patient.

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