Per Os Placement of Extragastric Devices
Methods and devices to externally create a restriction on the stomach are described. In some embodiments, the devices are contoured to fit the stomach and can be further anchored to the stomach. In further embodiments, the degree of deployment of the extragastric restriction device is controllable after implantation. In other embodiments, specialized wires, catheters, ports, and trocars specific for placement of extragastric restriction devices are presented. In still further embodiments, systems are described in which adjustability of the devices is provided along with sensing and actuating ability.
The present application is a continuation of U.S. patent application Ser. No. 11/395,302 filed Mar. 31, 2006 and titled “Extragastric Minimally Invasive Devices to Treat Obesity.”
The present application is also a continuation in part of U.S. patent application Ser. No. 11/334,105 entitled “Methods and Devices to Facilitate Connections Between Body Lumens” which is a continuation-in-part of patent application Ser. No. 11/295,281 titled “Obesity Treatment Systems” filed Dec. 6, 2005 which is a continuation-in-part of International Patent Application PCT/US2005/033683 filed Sep. 19, 2005, which is a continuation-in-part of U.S. Non-Provisional patent application Ser. No. 11/148,519 entitled “Methods and Devices for Percutaneous, Non-Laparoscopic Treatment of Obesity,” filed on Jun. 9, 2005 by Michael Gertner, MD, and is also a continuation-in-part of U.S. Non-Provisional patent application Ser. No. 11/153,791 entitled “Methods and Devices for the Surgical Creation of Satiety and Biofeedback Pathways,” filed on Jun. 15, 2005, both of which are continuation-in-parts of U.S. Non-Provisional patent application Ser. No. 11/125,547 by Michael Gertner, M.D., entitled “Percutaneous Gastroplasty” filed May 10th, 2005, which is a continuation-in-part of International Patent Application No. PCT/US05/09322 filed Mar. 19, 2005, designating the United States, entitled “DEVICE AND METHODS TO TREAT A PATIENT,” which is a continuation-in-part of U.S. Non-Provisional patent application Ser. No. 10/974,248 by Michael Gertner, M.D. filed Oct. 27, 2004, entitled “DEVICES AND METHODS TO TREAT A PATIENT,” which claims priority to U.S. Provisional Patent Application Ser. No. 60/556,004 filed Mar. 23, 2004 by Michael Gertner, M.D., entitled “BARIATRIC DEVICES AND IMPLANTATION METHODS,” to U.S. Provisional Patent Application Ser. No. 60/584,219 filed Jul. 1, 2004 by Michael Gertner, M.D., entitled “DEVICES AND METHODS FOR PERCUTANEOUS GASTROPLASTY,” to U.S. Provisional Patent Application Ser. No. 60/603,944 filed Aug. 23, 2004 by Michael Gertner, M.D., entitled “DEVICES AND METHODS TO TREAT MORBID OBESITY,” all of which are herein incorporated by reference in their entirety.BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to devices, methods and apparatus to treat obesity. Implantable devices, methods to implant implantable devices, and surgical devices to enable the implantation of the implantable devices in, around, or near the walls of organs or vessels are disclosed, including devices to appose the walls of the stomach. Feedback systems are also disclosed which enable multimodality therapy such as gastric restriction in combination with electrical stimulation of the stomach, sensing of feeding parameters, and/or other efferent or afferent neural pathways in a patient. Methods and related devices are also disclosed which relate to forming connections between body lumens.
2. Description of the Related Art
Obesity is a public health problem of extreme national and international importance. There are an estimated 60 million obese adults and 2 million obese adolescents in the United States as of 2004. By some estimates, there are 1 billion obese individuals worldwide. Indeed, to highlight the worldwide importance of the disease, a recent report estimated that over there are over 60 million obese individuals in China, a 10-fold increase since 2000. Obesity affects the life quality and productivity of those effected and leads to long-term health related complications such as diabetes and heart disease. Some researchers estimate that if the obesity epidemic is not brought under control, it could quickly overwhelm societal resources.
To date, surgery is the only proven method for inducing substantial weight loss. The mechanism behind the success of surgery is, in many cases, not known because obesity is such a complex, multifactorial disease. Some researchers propose that surgery does no more than provide biofeedback for appetite retraining. Other researchers maintain that surgery alters the physiology of the patient such that satiety is induced earlier or fewer nutrients are absorbed. Nonetheless, the consensus among most obesity researchers is that at the current time, long-term weight loss is only possible by surgical means and that the success of surgery is due to a multifactorial set of changes.
Over the past four decades, there have been numerous surgical procedures and devices developed to treat those who suffer from morbid obesity. In general, there are two physiologic components of all past and current procedures: malabsorption and mechanical restriction/volume reduction. Newer methods and devices include stimulation devices such as neurostimulators and muscle stimulators. In general, these devices will require further research and development before they will be used to treat obese patients as a single therapy.
Many of the procedures performed in the past have proven to be impractical, dangerous, and/or detrimental to patient health and are now of historical importance only. One example of a failed procedure was the jejuno-ileo bypass in which a malabsorptive state was created through the bypass of a large portion of the intestine through the creation of a surgical anastomosis between the jejunum and the ileum. While patients initially lost a great deal of weight, liver failure or liver damage occurred in over one-third of the patients, necessitating reversal of the surgical procedures.
One of the first restrictive type surgical procedures was the so-called “stomach stapling” operation in which a row of horizontal staples was placed across the upper stomach and then several staples were removed from the staple line to create an opening, the “os,” for a small amount of food, but not too much food. This procedure was mostly restrictive, leading to an early feeling of satiety. This surgery was abandoned because 70%-80% of patients had inadequate weight loss due to staple line dehiscence (i.e. the staples pulled through the stomach wall). A procedure to stabilize the staple line was performed by Smith et. al. (Lindsay B. Smith; Modification of the Gastric Partitioning Operation For Morbid Obesity. Am. J. Surgery 142, December 1981) in which the staple line was buttressed in the region where the staples were removed using teflon pledgets with sutures passing through the middle of the pledgets. The purpose of the pledgets was to buttress the suture and distribute the load across the suture to the pledget, thereby preventing the suture from pulling through the stomach and therefore stabilizing the os. The outcomes showed that the suture buttress was unequivocally able to prevent the suture from tearing through the stomach wall; indeed, over 90% of the patients showed excellent weight loss at 18 months.
The Roux-en-Y (The Roux) bypass operation has become the most commonly performed surgical procedure to treat the morbidly obese in the United States. It combines a small degree of malabsorption with a 90% reduction in the volume of the stomach. In the United States, 150,000 Roux procedures were performed in the year 2004. This number is expected to rise to 500,000 procedures by 2007. The procedure actually has been performed since the late 1970's but has evolved substantially over the past three decades into a relatively safe and effective procedure; indeed, the long-term data are very good. The advent of laparoscopic surgery and hence the laparoscopic Roux-en-Y bypass in combination with excellent follow-up results from the open (and laparoscopic) procedure are reasons for the proliferation of the Roux procedure.
Despite the efficacy of the Roux procedure and the recent laparoscopic improvements, it remains a highly invasive procedure with substantial morbidity, including a 1-2% surgical mortality, a 20-30% incidence of pulmonary morbidity such as pneumonia, pulmonary embolism, etc., and a 1-4% chance of leak at the anastomotic site which can result in a spectrum of consequences ranging from an extended hospital stay to death. Furthermore, it is not a good option for adolescents in whom the long-term consequences of malabsorption are not known. In addition, many patients resist such an irreversible, life altering procedure.
The Roux procedure requires general anesthesia and muscle paralysis which, in the morbidly obese population, is not of small consequence. There is also a substantial rate of anastomotic stricture which results in severe lifestyle changes for patients. As an example, many patients are forced to vomit after meals. Furthermore, although minor when compared to previous malabsorptive (e.g. jejuno-ileal bypass) procedures, the malabsorption created by the Roux-en-Y procedure can dramatically affect the quality of life of patients who undergo the procedure; for example, they may experience gas bloating, symptoms of the dumping syndrome, and/or dysphasia. In addition, these patients can experience very early fullness such that they are forced to vomit following meals.
Recently, minimally invasive procedures and devices which create a feeling of early satiety have been introduced into the marketplace in an attempt to address some of the issues above. The LAP-BAND™ is a band which encircles the stomach at the region of the fundus-cardia junction; it is a restrictive procedure similar to stomach stapling. It requires general anesthesia, a pneumoperitoneum, muscle paralysis, and extensive dissection of the stomach at the level the gastroesophageal junction. It also requires continual adjustment of the band, or restriction portion of the device. Although less invasive than the Roux procedure and potentially reversible, the LAP-BAND™ is nonetheless quite invasive. It also does not reduce the volume of the stomach by any great extent and some patients report a feeling of hunger much of the time. Furthermore, once implanted, the Lap-Band™, although it is adjustable by percutaneous means, is in fact very difficult to adjust and many iterative adjustments are required before it is made right.
Long-term clinical follow-up reveals that the banding procedure results in many complications. In a recently published article (Camerini et. al. Thirteen Years of Follow-up in Patients with Adjustable Silicone Gastric Banding for Obesity: Weight Loss and Constant Rate of Late Specific Complications. Obesity Surgery, 14, 1343-1348), the authors reported a 60% prevalence of late band removal secondary to complications such as erosion, slippage of the band, infection, or lack of effectiveness. Nonetheless, the LAP-BAND™ as a procedure is becoming very popular across the world as it is a less invasive and reversible procedure. The weight loss in long-term trials is considered adequate by some and inadequate by many; across various studies, the average weight loss is approximately 40% of excess body weight which is well below the weight loss in the Roux, VBG, and duodenal switch procedures (see below).
Other procedures which have been tried in the past and which offer varying degrees of weight loss include several variations of the original “gastroplasty” procedures. These procedures represent an evolution of the so-called “stomach stapling” procedure discussed above. These procedures were attempted prior to and concomitant with the evolution of the Roux-en-Y. They became popular (despite offering less weight loss than the Roux) because of their substantially less invasive nature and possible reversibility.
One such example is called the vertical banded gastroplasty, or VBG, which again, involves the creation of a restricting “os” for food. In the VBG, the border of the “os” is the lesser curvature of the stomach which is less apt to dilate than the fundus region of the stomach. Furthermore, the procedure completely excludes the fundus which is thought to easily dilate and in fact, is physiologically “programmed” to dilate during meals . . . so-called “receptive relaxation.” Dilation of the fundus as a result of continued overeating is a major reason for failure of the Lap-Band and in some cases the Roux procedure and the development of the VBG was intended to improve upon these outcomes. One issue with the VBG is that, as practiced today, it is not reversible, nor is it adjustable, and it is difficult to perform laparoscopically. As in the horizontal gastroplasty, the VBG utilizes standard staplers which, as in the horizontal gastroplasty, are unreliable when applied to the stomach. In the case of the VBG, the row of staples runs parallel to the lesser curvature of the stomach. An important reason for recurrent weight gain in the VBG is in fact recannulation of the staple line, leading to a so-called gastro-gastric fistula.
A recent, prospective, randomized trial, compared the VBG to the adjustable banding procedure and found that the VBG was overwhelmingly superior to the banding procedure (Morino et. al. Laparoscopic Adjustable Silicone Gastric Banding Versus Vertical Banded Gastroplasty in Morbidly Obese Patients. Annals of Surgery. Vol. 238 (6) pps. 835-842). Twenty five percent of the patients in the banding group returned to the operating room whereas there were no returns to the operating room in the gastroplasty group. The degree of weight loss was close to 60% of excess body weight after three years in the gastroplasty group and closer to 40% of excess body weight in the banding group. Although in this study, the VBG was successfully performed laparoscopically, the laparoscopic VBG procedure is in fact, difficult to perform, because the procedure is not standardized and a “tool box” does not exist for the surgeon to carry out the procedure; furthermore, the procedure is not a reversible one and relies on the inherently unreliable stapler systems.
A recent meta-analysis and systematic review (Buchwald et. al. Bariatric Surgery: A Systematic Review and Meta-analysis; JAMA vol. 292, no 14. pps 1724-1737) indicated that vertical gastroplasty (avg. excess weight loss of 68.2%) is superior to adjustable banding (avg excess weight loss of 47.5%) and gastric bypass (avg excess weight loss of 61.6%).
The Magenstrasse and Mill (M&M) procedure is an evolving gastroplasty technique wherein the greater curvature of the stomach is separated (stapled and cut) from the path of food, leaving a tube of stomach, the Magenstrasse, or “street of the stomach,” which is comprised of the lesser curvature. This procedure is similar to the VBG except that the longitudinal staple line of the stomach extends further along the lesser curvature and into the antrum. The theory behind leaving the antral “mill” is that it will continue to serve its normal function of mixing, grinding, retropulsion, and well-orchestrated expulsion of chyme into the duodenum. An authoritative study on the operation is incorporated herein by reference (Johnston et. al. The Magenstrasse and Mill Operation for Morbid Obesity; Obesity Surgery 13, 10-16).
In summary, the vertical gastroplasty procedure appears to be superior to the banding procedure. However, the vertical gastroplasty procedure is not easily performed laparoscopically and furthermore, it is not easily reversible. Therefore, a need exists to standardize the vertical banded gastroplasty and create a safer procedure which is also easy to perform, is durable, and is reversible.
The intragastric balloon is not a new concept. The intragastric balloon is meant to displace volume within the stomach such that a smaller volume of food leads to an earlier feeling of satiety. Currently, intragastric balloons on the market are not fixed to the stomach and consequently, can lead to complications such as obstruction and mucosal erosion. To avoid these complications, the balloons are removed after a maximum of six months. In a prospective, non-randomized, unblinded study (Sallet et. al. Brazilian Multicenter Study of the Intragastric Balloon; Obesity Surgery, 14, 991-998), the average excess weight loss was 48.3% after 1 year. However, the incidence of nausea and vomiting was 40% and epigastric pain was 20%; balloon impaction occurred in 0.6% of patients. A balloon which is fixed to the wall of the stomach could potentially improve the intragastric balloon device and allow longer-term implantation.
More recently, there has been an effort to develop even less invasive devices and procedures which do not involve incisions at all. For the most part, these procedures are performed from within the stomach with an endoscope and by a physician with a high degree of endoscopic skill. For example, U.S. Pat. No. 6,558,400 describes methods and devices to create partitions in the stomach. Anchors or staplers applied through an endoscope from within the stomach are used to accomplish the partitions. Similarly, U.S. Patent Application Publication No. 2004/0122456 describes another set of methods and devices to reduce the volume of the stomach. Expandable anchors are deployed both on the anterior and posterior wall of the stomach using an endoscope. Flexible sutures are brought out of the patient's mouth and the sutures are crimped together within the stomach in order to bring the walls of the stomach closer together. The final configuration has a discontinuous connector positioned between the anterior and posterior anchors. Patent application U.S. Pat. No. 6,773,440 describes a device which is advanced through an endoscope and grasps or applies suction to a fold of mucosa to apply anchors through the mucosal and serosal layers of the stomach.
Endoscopic procedures to manipulate the stomach can be time consuming because of the technical difficulty of the endoscopy; they also require a large endoscope through which many instruments need to be placed for these complex procedures. Due to the large size of the endoscope, patients typically will require general anesthesia, which limits the “non-invasive” aspects of the procedure. Furthermore, the procedures require advanced endoscopic skill which would need to be acquired by most endoscopic practitioners outside of academic institutions. Such skill adaptation can take a significant amount of time, which will limit adoption of the procedure by the physician community. A further issue is that there is a limitation on the size of the anchors and devices which can be placed in the stomach because the endoscope has a maximum permissible size.
Percutaneous Endoscopic Gastrostomy (PEG) refers to a procedure in which a gastrocutaneous tract is created using a percutaneous procedure (see below for definition). A recent update of the procedure can be found on the Society of American Gastrointestinal Endoscopic Surgeons (SAGES) website, and is incorporated herein by reference. Briefly, the procedure involves insufflation of the stomach with and under visualization with an endoscope. A small incision is made in the skin and a needle is advanced into the stomach (the stomach sits just under the abdominal wall when insufflated) under endoscopic visualization. A feeding tube is then placed over the needle to create a gastrocutaneous tract with the feeding tube inside the tract with the needle subsequently removed. The feeding tube is secured with an external bolster to creates a tubular tract from outside the patient through the skin of the abdominal wall and residing inside the stomach. Over the ensuing weeks, a permanent tract evolves between the stomach mucosa and epithelium of the skin, after which, the bolster can be removed without consequence. When the feeding tube is to be removed, the gastrocutaneous tract will close on its own as food will preferentially be delivered antegrade (the path of least resistance) to the duodenum, thereby allowing the tract to heal.SUMMARY OF THE INVENTION
A device for application to the external stomach surface of a patient comprising a first portion expandable from a collapsed state to an expanded state, a second portion coupled to the first portion contoured to fit an external portion of the stomach without encircling the stomach, a third portion coupled to the device which is slideable over a flexible connector comprising a proximal end and a distal end. The device wherein said first portion is a balloon. The device further comprising a fluid communication line in contact with said balloon. The device wherein said communication line and said connector are the same structure. In another embodiment, said first portion of the device and said second portion of the device are one in the same. The device wherein the second portion has a radius of between 0.25 and 5 centimeters and is curved to fit the cardia of the stomach when the first portion is in its expanded state. The device wherein the second portion is between 5 and 30 centimeters. The device wherein the connector further comprises an anchor at its distal end. The device can further contain a sensor
In one embodiment, a system is described comprising a device expandable from a first configuration to a second configuration wherein said device is contoured to partially surround a portion of the stomach without fully circumscribing the portion of the stomach; a connector coupled to said device and operable to adjust the degree of expansion between the first configuration and the second configuration; A port in communication with the connector said port operable to be accessed intermittently through the skin of a patient. The system further comprises at least one sensor which senses a force applied to the device. In another embodiment, the system comprises an actuator; in yet another embodiment, the system further comprises a fastening element attached between the device and outer layer of the stomach.
In another embodiment, a device to apply external compression to the stomach comprises a first structure with a first width and a second smaller width wherein the structure is constructed to bias toward the second smaller width unless a force is applied to maintain the first width. A second structure is attached to the first structure and constructed from a material which enables force to be applied to adjust the width of the first structure. In another embodiment, the device comprises a second structure which is a fluid fillable structure. In another embodiment, the first or second structure of the device comprises nitinol. In other embodiments, the first or second structure comprises an electroactive polymer. In further embodiments, the device further comprises a communicating line. In other embodiments, the communicating line is a fluidic communicating line. In further embodiments, the communicating line is an electrical communication line. In other embodiments, the device comprises at least one sensor or an electroactive polymer. In still further embodiments, the device further comprises a power supply and/or a microcontroller.
FIGS. 4A and 4A′ are a side and blow-up view, respectively, of one embodiment of a tissue grasping instrument with the distal end in its open configuration.
FIGS. 4B and 4B′ are a perspective and blow-up view, respectively, of the tissue grasping instrument of
FIGS. 4C and 4C′ are a perspective and blow-up view, respectively, of another embodiment of the tissue grasping instrument with the distal end in its closed configuration.
The region behind the stomach is referred to as the lesser peritoneal sac. It is a potential space between the retroperitoneum and the posterior wall of the stomach. The proximal limit of the lesser sac is the cardia of the stomach and the distal limit is the pylorus of the stomach; the superior limit is the liver and the inferior limit is the inferior border of the stomach. To the left of the midline, the posterior wall of the stomach is generally free from the peritoneal surface of the lesser sac and to the right of the midline, the posterior wall of the stomach is more adherent to the peritoneum of the lesser sac although the adherence is generally loose and the adhesions can be broken up rather easily with gentle dissection.
The stomach is comprised of several layers. The inner layer is the mucosa. The next layer is the submucosa followed by the outer muscular layers. Surrounding the muscular layers is the serosal layer. This layer is important with regard to implants and healing because it is the adhesive layer of the stomach; that is, it is the layer which, when breached, heals with scar tissue formation. Implants adhering to this layer are less likely, or not likely, to migrate into the stomach whereas implants only placed in the mucosal or submucosal layers will migrate. Reference to “stomach wall” or “wall of the stomach” as used herein include the entire thickness of the stomach, including the mucosa, submucosa, muscular layers, and serosa. The “anterior wall of the stomach” is the portion of the stomach closest to the muscular abdominal wall and the “posterior wall of the stomach” is the part of the stomach closest to the retroperitoneum.
“Transgastric fastening assembly” or “fastening system” refers to a permanent or semi-permanent implant and comprises at least one posterior anchor, at least one anterior anchor, and a connector to couple the posterior and anterior anchors. “Fastener” and “anchor” have their ordinary meaning and are used interchangeably in this disclosure. The “connector” can refer to any means of connection including but not limited to a material connection, an electromagnetic or magnetic connection, or a chemical connection. As used herein, a “connector” is a coupler or linker used to materially connect the anterior and posterior anchors. As used herein, the “posterior anchor” is the anchor in a preferred embodiment which is adjacent to the posterior wall of the stomach when deployed. The “anterior anchor” is the anchor in a preferred embodiment which is approximated to the anterior wall of the stomach when deployed.
As used herein and when referring to portions of a surgical instrument, “proximal” refers to the end of the instrument which is closest to the surgeon when the instrument is used for its intended purpose, and “distal” refers to the end of the instrument which is closest to the patient and when the instrument is used for its intended purpose. When used to refer to the gastrointestinal tract, “proximal” is toward the mouth and “distal” is toward the anus.
“Laparoscopic procedure” broadly refers to procedures which require pneumoperitoneum and general anesthesia. “Percutaneous procedure” broadly refers to surgeries which do not require general anesthesia or pneumoperitoneum. These broad terms are mutually exclusive for the purposes of the ensuing invention because the respective procedures require different levels of patient preparation and peri-operative treatments and therefore define specific embodiments. Similarly, endoscopic procedure refers to procedures that are performed entirely with an endoscope. In some descriptions, the terminology “percutaneous means” is used which generically refers to placing a surgical instrument through the skin of a patient and using the surgical instrument to accomplish a surgical task; in this more generic case, “percutaneous means” can be used with or without laparoscopic means and in laparoscopic procedures. Similarly, “laparoscopic means” generically refers to procedures performed under the guidance of an internal camera placed through the abdominal wall (that is, percutaneous means); in this more generic sense, laparoscopy can be used with or without percutaneous methodology though in most cases percutaneous means are a requirement for laparoscopic procedure. Similarly, endoscopic means refers to procedures involving some level of endoscopic visualization but is not completed with the endoscope alone whereas “endoscopic procedure” refers to a procedure performed entirely through an endoscope. “Surgery,” “surgical procedure,” and “surgically created” have their ordinary meaning and with regard to the inventions herein, is all-encompassing, and refers to laparoscopic surgery, open surgery, endoscopic surgery, and percutaneous surgery.
“Patient afferent pathway” refers to a pathway which transmits a signal to the sensorium of a patient; for example, the vagus nerve carries afferent fibers to the hypothalamus and pain centers of the brain. “Patient end-effector pathway refers to a pathway which directly effects a result in an end-organ; for example, stimulation of contraction in the stomach. Patient efferent and end-effector pathways can overlap and therefore, the terms should not be considered mutually exclusive; for example, stimulation of the stomach likely stimulates some nerve fibers that travel to the sensorium and stimulation of the vagus nerve likely stimulates the stomach. “Device afferent pathway” refers to a pathway which transmits a sensory signal to a restriction device; for example, a sensor which senses food intake transmits its signal to the restriction device through a device afferent pathway. “Device efferent pathway” refers to a pathway which transmits a signal from a restriction device to a separate structure (e.g. a device end-effector pathway described below) or device (e.g. patient afferent pathway, a patient end-effector pathway, or a device end-effector pathway). A “device end-effector pathway” is a signal that directly effects a device state; for example, the connector of a transgastric assembly is shortened or the diameter of a restriction band undergoes a change in its diameter size.
“Exogenous gastric feedback loop” or “exogenous satiety pathway” refer to implantable systems which enhance the biologic pathways which already exist in a patient (the endogenous feedback systems). For example, the VBG and the Lap-Band™ both “tell” the patient that he/she is “full,” and consequently to stop eating. That is, they induce a feeling of satiety (through dilation of the stomach proximal to the device) earlier than would otherwise be felt by the patient (this is an example of an endogenous satiety pathway). Exogenous or enhancement of these pathways refers to embodiments in which the satiety signal can be controlled and/or enhanced. For example, a sensor can be place on a restriction device and then a pathway, such as vagal nerve stimulation, can be activated in response to feedback from the sensor; therefore, satiety is induced at an earlier stage than if the endogenous feedback systems (stomach dilation) were relied upon.
“Gastric volume reducing devices, procedures and systems” and “gastric restriction devices, procedures and systems” have their ordinary meanings and overlap in meaning when the walls of the stomach are brought closer together. In these cases, all volume reducing procedures and restriction procedures which bring the walls of the stomach closer together necessarily overlap in meaning. “Gastric restriction devices” refer generally to any devices which restrict the stomach in some way. Included (but not limited to) are devices such as transgastric fastening assemblies, laparoscopic bands (e.g. the Lap-Band™), and intragastric balloons.
“Constricting bands” or “restricting bands” have their ordinary meaning and also refer to gastric restriction devices which surround the proximal region of the stomach. The constricting bands cause weight loss by restricting the food intake of the patient. In many cases, the restricting bands are adjustable balloons which are adjustable percutaneously by way of a port implanted at the time of surgery. These bands rely on the patient to inform the surgeon about eating habits and discomfort which may limit their utility because the patient can “cheat” themselves. Furthermore, the monthly or so follow up visits are potentially too infrequent to be useful. “Gastric restriction system” refers broadly to the restricting devices including both adjustable bands and devices such as transgastric fastening assemblies.Transgastric Fastening Assembly
In a preferred embodiment, the posterior anchor 14 is made from a biocompatible, radio-opaque, or magneto-opaque semi-rigid polymer; it can also be made from various kinds of suitable materials known to those of skill in the art including metals, metal alloys, plastics, natural materials or combinations thereof as discussed above in relation to the connector 12. In some embodiments, the anchor is made from a conductive material and in other embodiments the anchor is made from a combination of conducting, non-conducting, and/or semi-conducting materials. The posterior anchor 14 can be solid, or alternatively, can be porous, mesh-like, lattice-like, or umbrella-like. In some embodiments, the anchor contains a potential space on the inside which can be expanded by a fluid (e.g. gas or liquid). In a preferred embodiment, the posterior anchor is porous or has a porous mesh attached to it to encourage fibrous ingrowth such that it becomes permanently attached to the stomach or intestinal wall. Coatings can be added to the anchor to encourage tissue ingrowth; of course, such coatings do not limit the ability for the interior of the anchor to be a potential space for expansion by a fluid. In other embodiments, the posterior anchor is solid and/or treated to discourage tissue ingrowth (e.g. with a silicone coating). In other embodiments, the posterior anchor has a xenograft or allograft material attached to the anchor. In a preferred embodiment, the posterior anchor 14 is disc-shaped, but those of skill in the art will recognize that other embodiments are possible, such as those shown in
In the embodiment shown in
Other suitable means of fastening the connector to the posterior anchor are also contemplated and do not necessarily result in a connector and posterior anchor becoming permanently attached. For example, in one embodiment shown in
In the embodiment shown in
In a preferred embodiment, shown in
The inflatable posterior anchor can have a valve 38 located between the anchor body 34 and the connector 35. Alternatively, the valve is located in the portion of the connector located outside the patient, the valve (e.g. stopcock type valve) being controlled by the operator until the anterior anchor is placed (see below). In this alternative embodiment, the filling substance is trapped in the posterior anchor after the anterior anchor is deployed and the connector is cut and sealed, preferably flush with the anterior anchor (see below). The filling substance can be a gas, liquid, or material which changes phase with time (i.e. it may harden, cure, polymerize, or become a gel with time). Other materials such as magnetorheologic fluids (for example, magnetic particles immersed in an oil) can be used as well and such fluids would interface with the electrical systems described below. Preferably, the surface of the posterior anchor adjacent to the posterior wall of the stomach has a mesh fixed to it to encourage tissue ingrowth. In some embodiments, part or all of the anchor material is comprised of a biodegradable material.
In some embodiments, the anchor assembly and in particular the posterior anchor and connector combination are used for “extragastric volume reduction” of a region of the stomach (see below for more detail). In this embodiment, the posterior anchor can be adapted to be an extragastric restriction device and the anterior anchor-connector system is used for fixation of the device to the abdominal wall. In this embodiment, it may be desirable for the extragastric restriction device to have a shape that conforms to an area of the stomach such as the GE junction. The connector can serve as a conduit to fill the extragastric balloon and can further be equipped with a valve to fill the extragastric balloon and prevent leaking of its contents. The transverse width of the GE junction is typically 0.5 cm to 10 cm in almost the entire population and 1 cm to 5 cm in the majority of the population. The extragastric balloon should be shaped such that it can surround 180-270 degrees of the GE junction or from 90 degrees to 360 degrees. In some embodiments, the balloon can completely surround the GE junction and in these embodiments, the balloon can be continuous or discontinuous.
Other methods of introducing adjustability of the transgastric anchor assembly exist as well and are useful in some embodiments. For example, the suture can be produced from a material such as nickel-titanium alloy, the tension of which can be adjusted with an electrical current or other means of introducing a temperature increase in the alloy. In some embodiments below, the tension of the nickel-titanium alloy can be adjusted depending on an input parameter such as for example, the output from a sensor integral to a gastric restriction device (see below for more detail). In another embodiment, a nickel-titanium alloy is a novel component of a restricting band such as the Lap-Band™ (see below) or an extragastric restriction device which does not completely surround the stomach. In some embodiments, both a transgastric assembly and a restricting band are implanted in the patient and in some embodiments, the transgastric fastening assembly has an adjustable nitinol connector and in other embodiments, the restricting band has a nitinol ring which is adjustable via electrical means. In some embodiments both the transgastric anchor and the restricting band both have adjustable nitinol components. Alternative electroactive materials include electroactive polymers.
In any of the embodiments above, the connector can serve as a sensor to detect the tension imposed on it by the two fasteners moving in opposite directions. In embodiments where the connector serves as a sensor, the connector can be composed of one or more different materials. One of the materials can be a sensor or sensing material and the other serves as a material for mechanical strength. For example, a piezoelectric strain gauge can be used as a strain sensor as can an electroactive polymer. As discussed below, the connector (sensor) can serve as the afferent (device afferent) limb of a feedback loop. The efferent (device efferent) pathway of the feedback loop can be an electrical lead, which communicates with, and stimulates a pathway such as the vagus nerve (patient afferent pathway), a sympathetic pathway such as the celiac plexus, or a device efferent pathway which (for example) can adjust the degree of gastric volume reduction or restriction. When some or all of these efferent (neural and mechanical) pathways are stimulated, a feeling of satiety can be created and controlled in a patient. Such pathways may decrease or eliminate problems with constricting band and stapled gastroplasties because they offer solutions to decrease the amount of pressure applied by the devices to the stomach until the pressure is needed (when the patient is eating for example). Such methods and devices can potentially decrease the problems with erosion and reflux. Furthermore, the adjustment of the device can be taken out of the hands of the patient and controlled by the device and the surgeon. Furthermore, battery power can be conserved by apply electrical stimulation only when the patient is eating.
In an embodiment, the connector (or part of the connector) can take the form of a strain gauge in which a potential is generated which is proportional to the tension (stress) applied to it. The strain measurement in the connector can be transmitted wirelessly or through a wired connection to an effector limb (patient or device efferent pathway) of the circuit or to an external receiver. In other embodiments, the strain measurement is transmitted through a wired circuit (e.g. from the strain gauge directly to the efferent pathway of the feedback loop). In one example, the strain gauge is an electrically activateable polymer (electroactive polymer); in a separate embodiment, the efferent end of the feedback loop is also an electroactive polymer; in other embodiments, both the afferent and efferent limbs of the feedback system are made from electroactive polymers. In some embodiments, the efferent effector pathway is stimulation of the stomach wall surrounding the fasteners or the stomach wall in a place some distance away from the transgastric fastener assembly such as the peri-pyloric region. Stimulation of a patient end-effector (e.g. the stomach) pathway can be transmitted through the fastener itself or through a separately attached electrode.
In an alternative embodiment, the efferent limb of the feedback loop is an electrical lead which communicates with a cutaneous stimulator to negatively enforce excessive feeding behavior. In this embodiment, feedback to the patient is not necessarily a satiety signal but a cutaneous feedback signal which alerts the patient to an overfeeding state. In another embodiment, the feedback pathway is a computer algorithm which alerts the patient that they are overeating or saves the data until sometime in the future, then printing out the data for the patient or the physician. In other embodiments, the efferent limb of the feedback system generates loud sounds or vibrations.
The algorithm between the afferent and efferent pathway can be a simple one in which the efferent pathway has an on or off status depending on the level of stimulation from the afferent pathway. Alternatively, the relationship between the afferent and efferent pathways is non-linear. For example, as the strain increases, the efferent signal increases two- three- or fold. If the strain increases further, the efferent signal can increase in an exponential manner (for example, eight to ten-fold). Other patterns are possible as well and these patterns can be programmed into the controller or signal generator and represent the algorithmic aspects of the stimulation system. Nevertheless, the relationship between inputs and outputs of the system can be programmed from a location external to the devices and system (e.g. the surface of the patient or a remote location such as a physician's office).
In an alternative embodiment, it is contemplated that the connector 12 can have notches 51, which interact with gripping elements 46 in a ratchet-and-pawl mechanism similar to that used in cable ties, providing a one-way adjustability, in which the posterior and anterior anchors can be moved toward each other, but not away from each other.
An inflation tube 63 is used to inflate and deflate the anterior anchor. This inflation tube may or may not have a valve. In one preferred embodiment, the anterior anchor is filled with gas or fluid through the inflation tube and the fluid is held inside the anchor through an external (e.g. stopcock) valve controlled by the operator. When the inflation tube is cut at the end of the procedure, the inflation line is crimped closed thereby locking the inflating substance inside the anchor. Alternatively, the shears used to cut the inflation line can be metal and an electrocautery current can be applied through the shears and to the inflation line to weld it closed.
In a preferred embodiment, the anterior anchor is made from a biocompatible, radio- or magneto-opaque polymer, but it can also be made from various kinds of suitable materials known to those of skill in the art including metals, metal alloys, plastics, natural materials or combinations thereof as disclosed above; the anchor material can also be a biodegradable material. The anterior anchor can be solid, or alternatively, can be porous, mesh-like, umbrella-like or lattice-like. In a preferred embodiment, the anterior anchor is porous, mesh-like, umbrella-like or lattice-like to encourage fibrous ingrowth such that it becomes permanently attached to the stomach wall. Coatings can be added to the anchor, or a mesh material such as polypropylene can be fixed to the anchor surface, such that it touches the anterior stomach wall and encourages tissue ingrowth. In other embodiments, the anterior anchor is solid and treated to discourage tissue ingrowth with materials such as silicone, PTFE, or FEP which are generally hydrophobic and non-reactive. In one embodiment, one side of the anchor is produced from PTFE and the other side of the anchor is produced from polypropylene. In other embodiments, the anterior anchor has a xenograft or allograft material attached to the anchor which can encourage tissue ingrowth.
In a preferred embodiment, the anterior anchor is disc-shaped and substantially flat, but those of skill in the art will recognize that other embodiments are possible; for example, the anterior anchor can be elongate and/or continuous and can range in size from 5 mm to 10 cm, in which case, it can traverse the length or width of the stomach.
In some embodiments, the anterior anchors can have electrodes which can communicate electrically with a tissue (e.g. the stomach) after the anterior anchors are positioned in contact with the tissue (e.g. the stomach). The electrodes can pass through the material to communicate electrically with the connector traveling through the anterior fastener. The electrodes can communicate with other effector pathways (e.g. the vagus nerve or the muscle of the stomach) located at different anatomic regions from the anterior fastener.
In any of the above embodiments, the anterior and posterior anchors as well as the connector can have one or more magnets (electromagnetic, paramagnetic, magnetorheologic, or ferromagnetic materials) disposed within or on their surfaces. Such magnet can serve a variety of purposes. In one example, the magnets serve as actuators to forcefully maintain the walls of the stomach together through their inherent and continuous (or discontinuous in the case of an electromagnet) magnetic interaction. In other embodiments, the magnets serve as sensors to sense the amount of food taken in by a patient; in this embodiment, a change in a magnetic field (relative movement of the magnets) is detected as an inductive current and can be correlated to food intake. Such sensing mechanisms are well known in the mechanical arts. In another embodiment, the anchors contain a magnetorheologic fluid which can respond to an electrical current. When stimulated with a magnetic field, the magnetorheologic fluid will undergo a change in viscosity and create a more or less compliant anchor or connector. In this embodiment, once electrically charged, the increase in viscosity will enhance the effect of the anchors in creating restriction or volume reduction (or both) of the stomach (for example).Creation of an Anastomosis Between Two Body Lumens
The above devices and methods can further be adapted to create a connection or an anastomosis (such as a gastrojejunostomy, jejunojejunostomy, or ileocolostomy) between two body lumens. A gastrojejunostomy is the major anastomotic component of the Roux-n-Y bypass procedure, the jejunojejunostomy being the second component.
The lumens (90,100) can communicate with expandable elements or anchors along the connector and/or communicate with the gastrointestinal lumen. In one embodiment, one lumen communicates with one expandable element, and another lumen communicates with another expandable element on the elongate structure. In a further embodiment, an additional lumen (not shown) in the elongate structure communicates with the region between the expandable elements so that the quality of a connection between the two body lumens can be interrogated.
An expandable element 92 is further associated with the distal end of the connector 90. As described above, the expandable element, or anchor 92, can expand from an undeployed, to a deployed state, where the diameter of the tube in the deployed state is larger than the diameter of the tube in the undeployed state. Any of the materials, devices, and/or configurations mentioned above can be used in this embodiment. In this embodiment, a hole (e.g. enterotomy) in the body lumen 94 is created by a surgeon during a surgical procedure with or without assistance from the elongate structure; the enterotomy is approximately the size of the undeployed expandable element 92.
A second surgically created enterotomy 98 in a portion of a second body lumen (for example, small intestine) 98 allows for the connector-nasogastric tube to be further placed into the small intestine 98. The diameter of the connector-nasogastric tube 98 defines the ultimate diameter of the anastomosis between the stomach and the small intestine. Typically, in the Roux-en-Y procedure, the diameter of the anastomosis is very difficult to define accurately. The diameter of the connector-nasogastric tube can therefore be chosen to satisfy a pre-specified requirement for the diameter of an anastomosis. The expandable element 92 is then expanded in the small intestine and serves to enable the small intestine to be urged against the stomach 88. As described above, the expandable elements can be produced from any of a number of materials including shape memory materials, balloons, magnets, etc.
A second expandable element 99 (
After the urging step, the nasogastric connectors or lumens can be fixed with respect to one another so that compression 102 is applied between the two expandable elements and hence between the serosa of the two body lumens. The nasogastric connectors can be fixed temporarily (e.g. during application of an adhesive 106) or more permanently (e.g. 3-7 days after a procedure) with respect to one another depending on the method of creating an anastomosis between the two body lumens.
In one method of creating the anastomosis between body lumens, the expandable elements (92, 99) are comprised of magnets or electromagnets which attract one another. In this embodiment, the nasogastric connectors can be fixed by virtue of the magnets attracting one another, maintaining the nasogastric connectors fixed with respect to one another with the body lumens in between. In another embodiment, the expandable anchors are held fixed with respect to one another by virtue of the lumens of the nasogastric connectors being fixed with respect to one another (described above). The amount of compression created by any of these embodiments can be sensed with a tensiometer via the nasogastric connector or connectors. The compression between the body lumens can be applied for any period of time in order to produce an anastomosis. For example, the compression can be applied for a period of time during an operation when an adhesive 106 or sutures are applied to the apposed body lumens. Alternatively, the compression is applied over a longer period of time to allow for natural healing (natural compression anastomosis) of the anastomosis (e.g. 3-7 days). During a 3-7 day time period, the patient can be fed through a lumen of the nasogastric connector 90. A 3-7 day time period is long enough to allow for healing of an anastomosis or a leak from an anastomosis. With the current embodiment, the degree of compression of the anastomosis can be defined by a tensiometer.
In another embodiment (
In other embodiments, element 104 is responsive to activation by an electromagnetic means such as radiofrequency energy or optical energy. In some embodiments, the material of the element is chosen to facilitate adhesion. Examples of such materials include biomimetic materials (see above) or adhesive nanomaterials (for example, US patent application 20040250950 to Dubrow et. al. which describes devices comprising superadhesive nanomaterials which can be used in this embodiment).
In some embodiments, element 104 is a sensor which, when in place, can detect the strain or stress of a peristaltic wave or a food bolus passing through the anastomosis. In other embodiments, element 104 is an adjustable restriction device, an electrical stimulator, or a component of a closed loop feedback system. In another embodiment, element 104 is an electroactive polymer which can act as a sphincter on command from an electrical signal.
In one embodiment (
In some embodiments, the nasogastric connector is applied not to create an anastomosis 111, but to protect an anastomosis 111 (
In some embodiments, the transgastric fastening assemblies serve to reduce the volume of the stomach or restrict the entry of food, and in addition, provide for electrical stimulation and/or sensing; furthermore, the gain, or the relationship between an input parameter and an output parameter of the device, can be assigned prior to implantation of the device and/or can be adjusted after implantation of the device. In these embodiments, an electrical signal runs through electrodes in the transgastric fastening assemblies enroute from a sensor or enroute to alter the contraction patterns of the stomach and/or to electrically create a feeling of satiety through one or more afferent patient nervous pathways. Electrical stimulation can enhance or work synergistically with volume reduction and/or the creation of a restriction to flow in the stomach. Thus, fastener assemblies of the present invention can serve as sensing and/or stimulation structures which are useful, for example, in the creation of exogenous satiety feedback loops (see below).
In one embodiment, an exogenous gastric feedback loop (see
In one example, when the strain gauge is activated (e.g. by food passing through the stomach), a message is transmitted to the connector at which point the connector contracts to thereby prevent the flow of food into the stomach. Alternatively (or in addition to) in another embodiment, activation of the strain gauge transmits a signal to the device efferent pathway 720 which in turn sends a signal to the patient afferent pathway 722.
In addition, a gain controller 710 can be provided on the device in one embodiment in order to adjust the relative action (increase in connector tension or degree of stimulation of the vagus nerve) related to the sensing parameter. This device configuration allows the device to apply tension only when necessary (e.g. when food flows into the stomach). In some embodiments, this device configuration can allow for minimal tension to be applied to the device except when required (e.g. when food flows into the stomach). This configuration can save power, may also lead to a decreased tendency for erosion of the devices, and/or may prevent associated complications with the devices such as the Lap-Band™ such as reflux. For example, an electroactive polymer can serve as the controllable actuator; when a food bolus is sensed by the sensor, the polymer is stimulated to change shape and therefore act as a flow restrictor. When the stimulation (i.e. food bolus) ends, the voltage applied to the electroactive polymer is decreased, thereby allowing food to enter the stomach once again. In this case, there is only gastric restriction during food boluses.
In another embodiment of an exogenous satiety pathway (
In some embodiments, the band also has a balloon which is adjusted by nickel-titanium or by a magnetorheologic fluid (for example), which can also be used to fill the balloon portion of the band. After detecting a feeding state, an electric current passes through the magnetorheologic fluid or through an electromagnet which allow the band to become firmer, more viscous, or less compliant, and thereby more difficult for food to pass through the band. In states when the patient is not taking any food, the fluid inside the balloon is soft and does not apply pressure to the stomach wall.
By detecting the flow of food through the region of the restriction device and inducing restriction electrically in these embodiments, the stress on the stomach can be limited to predominantly the “on” time of the restricting device. This arrangement can limit the tendency for erosion exhibited by implantable devices and can also limit the power requirement for electrical stimulation or to change the diameter of the band. In other embodiments, the device end-effector pathways which adjust the restriction elements run in parallel with the sensor but are composed of separate materials. In some embodiments, these devices are further equipped with gain control in which the relationship between the inputs and outputs can be modified. Such gain controls can further be modified externally with a wireless type transmitter.
Exogenously created satiety pathways can further contain a control system 819 (
In another embodiment, a sensor (device afferent pathway) 817 is implanted using the methods and devices described herein (e.g. the connector-fastener system and implantation tools described above and below); the sensor 817 can communicate with or be a component of the stimulator and/or the restriction device. In one embodiment, a sensor is placed in the stomach wall (with or without a restricting structure) and senses stretch in the stomach; in another embodiment, the sensor detects transgastric stress and strain or circumferential stress or strain. This sensor can communicate with the stimulator or restricting device to create a feedback loop in which stretch is sensed (the sensor) and then a signal is sent to the stimulator portion of the system (e.g. the device efferent pathway) wherein a nerve (e.g. the patient afferent pathway), for example, the vagus nerve or sympathetic plexus, is stimulated to prompt the patient to slow their intake of food. The end-effecter (patient end-effector pathway) of the feedback loop does not have to be a nervous structure and in some embodiments is a muscular portion of the stomach or duodenum such as the pyloric channel, the antrum, the cardia, or the fundus. In some embodiments, the patient end-effecter pathway is a stimulus such as a small electrical current under the skin to inform the patient that the stomach is full and to stop food intake. In another embodiment, the patient end-effector is an audible alarm. In some embodiments, the device end-effector pathway is an actuator on the gastric band or near to the band and the end-effector can have its power output automatically adjusted. In one embodiment, a transgastric fastening assembly serves to reduce the volume of the stomach as well as provide for electrical stimulation. In this embodiment, an electrical signal runs through electrodes in the transgastric fastener assembly to possibly alter the contraction patterns of the stomach or to electrically create a feeling of satiety in addition to reducing the volume of the stomach and creating a restriction to flow in the stomach. Thus, fastener assemblies of the present invention can serve as electrodes which are useful, for example, for gastric electrical stimulation.
In one embodiment, an exogenous satiety pathway is recreated surgically by implanting a transgastric fastening assembly wherein the connector is adapted to be a strain gauge. In this embodiment, transgastric anchors serve as anchors and/or stimulators and/or sensors in addition to reducing volume or causing mechanical restriction. The fastening assembly is further connected via a device efferent pathway to a patient afferent pathway. Examples of patient afferent pathways include the parasympathetic or sympathetic nervous systems which contain patient afferent fibers which can induce satiety.
In another embodiment, a satiety pathway is recreated surgically by placing a constricting device around a portion of the stomach where the constricting device is able to sense circumferential tension or pressure such as, for example, would be created when food flows through the distal esophagus and proximal stomach. Surgical constricting devices include devices such as the Lap-Band™, transgastric anchor assemblies, or the extragastric restricting devices (e.g. a balloon) discussed below. Any or all of these devices can also be placed around or near an anastomosis such as a Roux-n-Y anastomosis.
In one embodiment (
In one preferred embodiment, a pressure sensor can be incorporated into the bottom portion of the port 1080 by cutting a hole in the port and placing the pressure sensor through the hole so that it is in fluid communication with the fluid inside the port. The sensor can further communicate with a transmitter (e.g. a wireless transmitter) 1090 and power supply. The power supply does not have to be implanted; for example, power can be delivered inductively and remotely to the pressure sensor through the skin. Furthermore, the pressure sensor can communicate with an automated system which fills and/or empties the port based on measurements from the pressure sensor. In other embodiments, a pressure sensor communicates with the inflation tube from the adjustable band in a T configuration.
In some embodiments, sensor 1020 is not a pressure sensor but a temperature sensor, pH sensor, etc. The pressure sensor is incorporated into system 1060, which in one embodiment is an electronic control system which incorporates the pressure sensor and the output 1050 (e.g. a stimulator). Output 1050 is any of the patient or device efferent or afferent outputs described above and below; in one embodiment, the output pathway is a stomach muscle stimulator 1070 which also stimulates vagal afferents and/or vagal efferent pathways. Required, but not shown is a source of power which, as is well-known in the art, is required for operation of the system and can be delivered remotely or through an integral power supply.
In another embodiment of the current invention, a neurostimulator or neurostimulator lead is a component of the restriction or volume reducing device (but does not have to be an integral component; for example, it can be distal in the stomach yet communicate with the restricting device) and is placed in the serosal layer of the stomach or small intestine to stimulate the muscular or nervous portion of the stomach or small intestine (e.g. the duodenum). In some embodiments, the stimulator contacts and acts on the parasympathetic, the enteric, or the sympathetic nervous system; in other embodiments, the stimulator acts on the muscular portion of the stomach. The stimulator can be placed anywhere along the stomach including the anterior and/or posterior walls of the stomach. In some embodiments, the stimulator contacts the mucosa and in other embodiments, the stimulator does not contact the mucosa. In some embodiments, a sensor is placed as a component of the stimulator or as a separate device. In some embodiments, the stimulator further communicates with a second or third stimulator through a wired or wireless connection.
Extragastric Restriction Devices
In another embodiment, an extragastric balloon (
In one embodiment, an anchor is used to fix the extragastric balloon to the stomach using an endoscope in combination with a guidewire (guidewires are thin flexible wires which are well known in the cardiology and gastroenterology fields) which is also placed through the endoscope. In some embodiments, guidewires are used through laparoscopic trocars or directly through incisions in the skin of the abdominal wall; in some embodiments, guidewires are similar to the connectors discussed above. In some embodiments, the balloon is attached to fixation points other than the abdominal wall 304 and stomach wall 302. For example, the balloon can be attached to the diaphragm, the liver, the colon, or the omentum. In some embodiments, an expandable device other than a balloon is used. For example, the expandable device can be an expandable cage which expands based on pre-stressed metal or polymer which then returns to its pre-determined shape.
The extragastric balloon can be placed anywhere along the stomach, even at a position 1-5 cm below the gastroesophageal junction at the same place where laparoscopically placed adjustable gastric bands are currently placed. The balloon can further be shaped to partially circumscribe, or form a lumen (fully circumscribe) around, a structure such as the gastroesophageal junction. The balloon can have roughened regions to improve friction and/or adhesion with the stomach. The balloon can further have support structures (either separate materials or components of the same material with different mechanical properties) 438 which are rigid or more rigid than the balloon.
Even though the balloon may completely circumscribe the stomach, it does not necessarily have to be a continuous ring and can be discontinuous even though it forms a complete ring when fully expanded. For example,
In one embodiment, device 430 is not an expanding device but is made from a material which tends to contract passively or actively. For example, device 430 can be made from a material such nitinol which starts at a first width and tends to move toward a smaller width unless a force is applied to prevent contraction of the width. If the device in this embodiment were designed for a region of the stomach 1-5 cm below the GE junction, the device may be tend to begin at a width of from 5-10 cm, then contracting to width of between 0.5 cm and 4 cm. The material which composes device 430 in this embodiment can be produced from a material such as nitinol 434 which creates rigidity along one portion of the expandable device 430 or itself is adjustable; for example, a fluid fillable balloon can be attached to the nitinol structure. Alternative materials for this embodiment include a variety of electroactive polymers. Any of the sensors, actuators, and systems described above and below can be incorporated into this embodiment.
In one embodiment, a material configured as a mesh (
The extragastric balloons and/or other devices can further be configured to act as stimulators which can deliver electrical current or sense certain parameters such as peristaltic contraction or food boluses. Electroactive polymers and shape memory alloys can also be used as sensors and/or actuators. In one example, the electroactive polymer consists of multiple polymer layers wherein one of the layers comprises a sensor such as a strain gauge or pressure gauge. This information can be used to increase or decrease the volume of the balloon accordingly.
As described above, any of the extragastric balloon embodiments can further contain an integral sensor to detect changes in volume (for example, volume and/or pressure changes) of the restricted portion of the stomach. Such changes in volume can then be used to create satiety feedback loops to deter the patient from further food intake (as discussed above and below, for example, vagal nerve stimulation).
In some embodiments, mechanical fixation structures are used to attach the balloon to the serosa of the stomach. Other means of attaching balloons to the stomach include adhesives, pledgets, expandable anchors, etc. The connector-anchor systems above are used to attach the balloon to the abdominal wall. The connector can further serve as an inflation valve for the extragastric balloon.
In another embodiment (
Surgical instruments which can be used to implant many of the devices of this invention are disclosed. The surgical instruments represent one example of the methods to implant the disclosed device but not the only possible means for implantation. Any of the devices and/or methods and/or features of the current inventions can be implanted with an endoscopic procedure in addition to endoscopic means to assist a percutaneous procedure or an endoscopic means to assist a laparoscopic procedure.
The distal end of the grasping instrument 200 is configured to cut, puncture, or dilate tissue when the jaws 220 are in the closed position. In one embodiment shown in
It also should be realized to one skilled in the art that the closed end of the grasping device does not have to be the only instrument responsible for cutting through the tissue; the central lumen 230 of the device can be utilized to assist in tissue penetration. For example, a needle (e.g. a Veres needle) 232 can be passed through the lumen and the needle 232 can make the initial puncture through the tissue. The configuration of the distal end of the grasper is meant to be a tissue dilator and facilitator of the entry into the stomach (or any other hollow organ) after the needle makes the initial puncture. For safety, the needle can be retracted as the tissue grasper dilates the tissue.
In the embodiment of the tissue grasper 200 illustrated in
The tubular middle sleeve 260 of the anchor grasping instrument has a portion of a handle 262 attached at the proximal end 261 of the instrument. Disposed within the middle sleeve 260 is a tubular inner member 264 which has an outer diameter such that it can slide within the middle sleeve 260 in the direction of the longitudinal axis of the middle sleeve 260 but cannot move substantially in transverse to the longitudinal axis of the middle sleeve 260. At the proximal end of the inner member, a second portion of a handle 266 is attached.
The distal tip 263 of the instrument is illustrated in more detail in
The instrument is designed such that the anterior anchor is easily manipulated. When the anterior anchor is in its substantially folded or compressed configuration as in
An important feature of the anterior anchor in some embodiments is that it be grippable by a laparoscopic grasping instrument and able to be translated through a laparoscopic port; further, the anterior anchor is reversibly translatable along the connector such that the surgeon can place and replace depending on what is seen by the endoscopist or the tension indicated by the tensiometers. If the surgeon wants to readjust the anterior anchor, connector 12 is manipulated so that the hooks 52 of the anterior anchor are brought into contact with hooking members 270; middle sleeve 260 is advanced distally from the operator, permitting hooking members 270 to engage the hooks 52; such contact is facilitated by pulling back (proximally) on the connector 12. By manipulating the middle sleeve 260 over the hooking members 270, the hooks 274 on the ends of the hooking members 270 can engage the hooks 52 on the anterior anchor 40. The outer sheath 252 is then slid over the anterior anchor 40 (or the anchor-middle sleeve complex is withdrawn into the outer sheath 252), until it is compressed into an undeployed configuration as shown in
In an embodiment where an inflatable anterior anchor such as the one illustrated in
A particularly advantageous laparoscopic port is one which allows visualization (with a laparoscope) of the individual abdominal layers as the laparoscope is being pushed through the abdominal wall (well known to those skilled in the art). Use of such a port allows the surgeon to “see” the different layers of the abdominal wall from within the trocar (using a standard laparoscopic camera) as the trocar is advanced through the abdominal wall. The endoscopic light inside the stomach will be “seen” by the surgeon as the port approaches the inner layers of the abdominal wall because the endoscopic light source transilluminates through the layers of the stomach wall and inner layers of the abdominal wall. Such visualization is advantageous if the patient has a very thick abdominal wall (e.g. in a morbidly obese patient) because the surgeon needs to ensure that another organ (e.g. the colon) is not positioned between the stomach and the posterior wall of the abdomen. Once the transillumination of the stomach is visible through the transparent port, the port 306 can be slipped in the abdomen between the abdominal wall and the anterior wall of the stomach. This portion of the procedure may be done without pneumoperitoneum and without general anesthesia (e.g. local anesthesia).
At this point, the camera can also be used to visualize the anterior wall of the stomach and/or it can be used to visualize placement of devices into the anterior wall of the stomach; examples of some devices include stimulators, sutures, clips, drug delivery devices, sensors, and volume displacing devices (extragastric balloons are discussed below). As described above, visualization of the surface of the stomach and implantation of devices into the anterior wall (without puncturing through the stomach) can be achieved with this method and does not require general pneumoperitoneum. The camera can be slid along the stomach to reach virtually any portion of the anterior stomach, duodenal wall, or lower esophagus. Additional ports can also be placed in the space between the abdominal wall and the anterior wall of the stomach. With the additional ports, additional instruments can be used which can facilitate placement of the devices into the walls of the stomach. Suture passers, knot tiers, electrosurgical devices, and clip appliers are just some examples of instruments which already exist in the surgical arts and which can be utilized to facilitate placement of devices into the walls of the stomach. Small incisions can be made in the serosa of the stomach and a pocket can be made so that stimulators can be placed in a pouch in the stomach wall. Therefore, using the inventive technique of entering the abdomen without general anesthesia and without pneumoperitoneum as detailed above, many different gastric operations can be performed.
At this point in the procedure (or any other point), a therapeutic energy device can also be applied to the stomach. For example, a laser (or other phototherapy device), a radiofrequency device, a microwave device, or an ultrasound device can be applied to the stomach. Furthermore, electrical or nervous mapping can be performed with the surgical device in the position between the anterior wall of the stomach and the abdominal wall. In the embodiment where an extragastric balloon is being deployed (see above and below), such deployment can proceed at this step. The ability to perform these procedures without general pneumoperitoneum and with minimal anesthesia is enabled by the inventive methods described above. Furthermore, in the embodiment where balloons are placed inside the stomach or neuro- or muscular stimulators or other devices are placed in the walls of the stomach, these devices are implanted at this step and do not require pneumoperitoneum or general anesthesia.
At this point in the percutaneous procedure (after entry into the stomach), the tissue grasping instrument 200 of
In an alternative embodiment, the space of the lesser peritoneal sac is not expanded before the posterior anchor is placed. For example, in an embodiment where an inflatable posterior anchor is used, the potential space can be expanded by the anchor itself as it is inflated to its deployed configuration.
In another embodiment, the posterior anchor is directly implanted in the retroperitoneum rather than in the lesser peritoneal sac. In this embodiment, the posterior anchor is placed in the retroperitoneum above the envelope of the lesser peritoneal sac. Above the envelope, the retroperitoneum is safe, being above the pancreas and splenic vessels. As is known to those skilled in the art of bariatric surgery, the Lap-Band® is implanted at this spot in the retroperitoneum (however, implantation requires general anesthesia and pneumoperitoneum). A Cat-Scan, MRI, fluoroscopy, or ultrasound can be used to assist in this step.Laparoscopic Procedure
In the “laparoscopic procedure,” after insufflation (pneumoperitoneum and general anesthesia) of the abdominal cavity with a Veres needle, a retrogastric tunnel 500 is created as is well known in the surgical arts and is shown in
In some embodiments, a suture is provided on the posterior anchor 510 (not shown) prior to insertion of the connector 332; connector 332 is adapted to pull the suture through the stomach and thence through the abdominal wall after being inserted through the anterior and posterior wall of the stomach. This results in a configuration similar to
When the connector 332 reaches the posterior anchor 510, gripping elements 520 are released by the surgeon through a mechanism which is integrated into the laparoscopic tool 500. Connector 332 is fixed to posterior anchor 510 through a locking mechanism. Mechanisms of locking connector 332 to posterior anchor 510 are well-known to those skilled in the art of mechanical fixturing. Some or all of the fixturing mechanisms may reside on the connector or on the anchor. In another embodiment, the gripping force of the grippers 520 can be overcome by force applied by the surgeon on connector 332. Reversible locking means other than mechanical means also exist and include magnetic, electromagnetic, and adhesive means.
An anterior anchor 550 (
In a preferred embodiment, the inflatable anterior anchor of
In another embodiment (
With the transgastric fastening assembly complete, the surgeon can examine the resulting configuration of the stomach using an endoscope. If one or more anterior anchors is/are not in the desired location, its placement along the connector can be adjusted as described above. Alternatively, in another embodiment, the anterior anchor can be urged closer to the posterior anchor simply by pushing it along the connector without using the implantation device to capture the anchor and deform it into its reduced profile configuration.
In another embodiment, the anterior anchor can be deflated, allowing the anterior anchor to be repositioned (the anterior anchor is reversibly fixed to the connector), and then reinflated to engage the connector.
When more than one transgastric fastening assembly is to be implanted, it is sometimes preferred to insert all of the posterior anchors and connectors before attaching any or all anterior anchors. For example, in
In an alternative embodiment, the stomach is fastened to the abdominal wall rather than there being a free space between the anterior gastric wall and the peritoneum of the abdominal wall (not shown). The initial steps are as discussed above. After the posterior anchors are placed, their position can be tested as depicted in
The connector 326 (e.g. a suture) of a preferred embodiment of the deployed transgastric fastening assembly, as illustrated in
Even if there is some degree of fusion between the mucosa around the connector at the region of the assembly, once the connector is cut or absorbed, the walls will tend to move apart over time. Alternatively, a balloon or other dissection device is introduced through an endoscope and used to urge apart the walls of the stomach at the point of fusion.Additional Embodiments of the Disclosed Devices, Instruments and Methods
The devices, methods and instruments disclosed above and below can be used to treat other diseases, such as gastroesophageal reflux disease (GERD). In this embodiment, a transgastric fastening assembly is placed in the cardia region. Such a configuration would maintain the position of the GE junction in the abdomen and potentially create a barrier to reflux contents. Similar to the devices above, feedback systems can be instituted so that the reflux prevention is initiated as a response to a stimulus such as pH or peristalsis rather than applying continuous pressure to the tissue even when reflux is not present. Furthermore, GERD devices can be equipped with patient controlled features such that when the patient feels symptoms, the antireflux features are activated. Reflux disease can also be treated with sutures or plications placed with a percutaneous procedure and in the region of the GE junction. Placement of the sutures (with or without pledgets) with a percutaneous procedure would not require general anesthesia and would be advantageous in many patients.
In many of the embodiments discussed above, a transverse row of fasteners is depicted which is one method of creating volume reduction or flow restriction.
Food ingested by the patient follows a physiologic pathway for digestion depicted by the arrow in
In another embodiment, a transgastric fastening assembly is placed in the antrum 408 or the region just proximal to the pyloric sphincter 410 if deemed necessary by the gastroenterologist and/or surgeon. Such a configuration would not reduce the volume of the stomach but would cause a feeling of fullness similar to a gastric outlet obstruction, leading to decreased food intake and weight loss. The anchors in this region can also conduct a current to electrically stimulate the pyloric region to simulate satiety.
In another embodiment, a transgastric fastening assembly may be required at the region of the cardia 402 to treat morbid obesity in a similar manner to that utilized with the LAP-BAND™ (Inamed Corp., Santa Barbara, Calif.). In this embodiment, the transgastric fastening assembly is not utilized to reduce the volume of the stomach, but to create a restriction to the inflow of food. In this embodiment, the fastening system can traverse the cardia but does not necessarily completely oppose the mucosal surfaces of the anterior and posterior walls of the stomach. In some embodiments, the transgastric assemblies do in fact completely appose the walls of the stomach together but allow food to pass through by not completely traversing the cardia, leaving a space for flow of food stuffs. The assembly can further be configured to provide electrical signals to the anterior and/or posterior portions of the stomach in this region. The active region of this embodiment can be quite large, in some cases ranging up to 10-15 cm, large enough to traverse almost the entire width of the cardia.
In another embodiment, the disclosed methods in combination with the transgastric fastening assemblies can be adapted to attach a gastrointestinal organ to the abdominal wall which, in addition to reducing volume, can also create a kink in the organ (e.g. the stomach). The kink may cause a resistance barrier (in addition to volume reduction) to gastrointestinal contents and can be useful to treat reflux disease or morbid obesity. Such a kink would also fix the gastrointestinal region to the abdominal wall as well as maintain the reduction of a hiatal hernia in the abdominal compartment (e.g. in reflux disease). A major component of reflux disease is a hiatal hernia in which the gastroesophageal junction freely slides from the abdomen to the mediastinum. A percutaneously placed suture or anchor in the region of the gastric cardia and/or fundus can tether the junction to the abdominal wall and confine the junction to the abdomen.
In other embodiments, the devices and methods of this invention can assist in the implantation of devices such as stents, meshes, stitches, or tubes in the gastrointestinal tract. A major technical difficulty encountered in placing stents, tubes, balloons, stimulators, and meshes inside the lumen of the gastrointestinal tract is that they tend to migrate because the walls of such devices do not adhere to slippery mucosa. A transgastric or transintestinal anchor, implanted with the current instrumentation, could solve this problem. Such a method would be particularly useful in the attachment of the stent part of the stent-sleeve system outlined in patent application US20050075622A1, or the mesh of patent application US20040172141A1. In another example, devices such as those disclosed in patent U.S. Pat. No. 6,773,441 attempt to place an endoscopic stitch to tether the cardia of the stomach to the fundus to treat reflux disease. Such stitches are tenuous in the long term because they do not necessarily penetrate the serosa. Even if the stitches penetrate the serosa, they tend to erode through the wall with time because of their thin profile and an inability of the endoscopic operator to control tension on the suture when it is placed. With the methods and devices of this invention, such an endoscopic suture can be buttressed with a percutaneously placed anchor.
Although the described methods are focused on the implantation of transgastric fastening assemblies to reduce the volume of the stomach or to increase the resistance to the flow of food in the stomach, the methods and devices can easily be expanded to the implantation of other types of devices such as neurostimulators, gastric muscle stimulators, gastric balloons, and bulking devices inside the wall of a gastrointestinal organ using the percutaneous procedures and devices described herein.
The methods disclosed herein (e.g. the percutaneous procedure) can further be used to apply an energy source to an internal organ without having to give general anesthesia or pneumoperitoneum. For example, the methods and devices of the current invention can be used to apply radiofrequency probes, microwave probes, ultrasound probes, and radioactive probes (to the serosa) in similar ways as disclosed in U.S. Pat. No. 6,872,206. The energy sources can be temporary or permanent and can be activated remotely through the abdominal wall in the case where they are implantable. The methods can further be used for diagnostic purposes prior to performing a surgical therapy. In one example, the methods and devices are used to identify specific nerves or nerve plexuses prior to delivering a specific therapy. In another example, specific hormone producing regions, such as ghrelin, are identified prior to delivering a specific therapy. Following the methods and devices outlined both above and below, instruments can be placed in the abdominal cavity under percutaneous guidance. Any of the layers of the stomach can be accessed and stimulation, ablation, or diagnostic devices can subsequently be placed without anesthesia and without pneumoperitoneum. For example, a stimulation device can be placed in any layer of the stomach wall such as the serosa or muscular layers for example.
Similarly, the anchor assemblies and anchors are applied to solid organs such as the spleen, kidney, liver, and pancreas to urge the edges of a defect together to promote healing; in other embodiments, the anchor assemblies are applied to the blood vessels such as arteries or veins; for example, the aorta or vena cava.
In still further embodiments, fascial defects can be closed with the anchoring assembly described above.
In some embodiments, the methods and devices described herein are used to place devices inside or outside the stomach; inside or outside the lesser sac of the peritoneum; inside or beside a structure within the retroperitoneum; inside, beside, or outside the duodenum, pylorus, or gastroesophageal junction. Implanted devices include but are not limited to the anchor devices and transgastric fastening assemblies described above; stents, meshes, stent-grafts, stitches, stimulators, and bulk forming agents can be implanted individually, in combination, and as a component of the same device.
In some embodiments, a transgastric method of placing such stimulators is described which in some embodiments enable placement of stimulators in the lesser peritoneal space where they can stimulate the sympathetic system or directly stimulate structures in the lesser peritoneal sac (such as the pancreas). In these and other embodiments, the transgastric access method to the lesser peritoneal sac is used to place stimulators and stimulate and/or inhibit pain fibers in and around the celiac ganglion. This type of procedure is used to treat patients with severe pain from a tumor or from pancreatitis.
Devices that circumscribe the gastroesophageal junction are well-known in the art (see for example, U.S. Pat. No. 6,465,3213); the surgical constricting balloons can be retrofitted with sensors in order to create device afferent pathways which detect overeating and simulate (via device efferent pathways) patient afferent pathways such as the vagus nerve or the visceral nervous system.
The methods and devices of this invention can also be used to place sutures in the stomach or pylorus to treat reflux disease or obesity. Such suturing would be facilitated by the placement of multiple ports through the walls of the stomach. Any of these methods and devices could be used in combination with or in place of the transgastric fastening assemblies to induce weight loss in a patient.
In another embodiment, the novel methods, implantation devices, and anchors of this invention are used to implant devices in one wall of a gastrointestinal organ without volume reduction. One example of such an embodiment is illustrated in
In another embodiment, a surgical anastomosis is surrounded with the organ spanning anchors and anchor assemblies of the current invention. In this embodiment, the anchors can buttress the anastomosis to protect the integrity of the anastomosis. The buttresses can support both hand-sewn and stapler anastomotic techniques. To prevent or the anchors are placed around or through the anastomosis. In a similar embodiment, a transgastric anchor system (or constricting band) can be used at a gastrojejunostomy in a Roux-n-Y bypass procedure. Both the transgastric anchor system and constricting band can further have associated electrically activateable elements through which flow through the anastomosis can be controlled.
The anchors (and bands), as described above, can also be used to control the flow of material through an anastomosis. Flow control is attainable when an anchoring assembly is applied across an anastomosis and are linked by means of a connector through the anastomosis. The distance between the anchors determines the amount of flow through the anastomosis and therefore, the flow rate can be adjusted quite readily with the device of the current invention. The flow rate is adjustable at anytime during or after the operation. Luminal devices to control the flow rate through an anastomosis can be found in US patent application number 20050022827. The devices of the current invention can be used to accomplish the goal of controlling flow through an anastomosis by placing anchors on either side of the anastomosis with a connector that traverses the anastomosis. Furthermore, the anastomotic flow control device can further have automated control using the materials, methods, and control systems described above in order to automatically adjust flow control or tension on the anastomosis.
In another embodiment, the anchor assemblies are applied to the lung to treat chronic obstructive pulmonary disease (COPD) via functional lung reduction. Rather than removing a portion of the lung (the surgical procedure), the anchors of the current invention are placed through the diseased portion of the lung to close off or at least create a large resistance in one portion of the lung and broncheoalveolar tree so that inspired air does not reach a malfunctioning portion of the lung.
In other embodiments of the current invention, the fastening systems and tools to implant the fastening systems are used to secure closure or repair of blood vessels. The blood vessels can be named vessels such as the aorta, vena cava, pulmonary veins, pulmonary arteries, renal vein, renal artery, inferior mesenteric vein and/or artery, splenic vein and/or artery, portal vein and/or hepatic artery, or the saphenous and/or deep veins. Alternatively, the vessels are unnamed such as in the case of the mesentery of the colon or small bowel. Vessel closure with the current system is possibly more efficient than current laparoscopic means of vessel closure which involve staple or clip occlusion of the vessels; staples and clips do not penetrate the vessel and therefore are often inadequate, or at least do not replicate what a surgeon would do in an open procedure which is place a suture through the vessel to “suture ligate” it as is well-known in the art.
It is also possible that a part of, or any or all of the devices and methods described above are performed with an alternative imaging means; for example, fluoroscope, MRI, ultrasound, and CAT scan.
Although the present invention has been described in the context of certain preferred or illustrative embodiments, it should be understood that the scope of the exclusive right granted by this patent is not limited to those embodiments, but instead is the full lawful scope of the appended claims.
Furthermore, any of the devices, methods, surgical instruments, and features can be used singly or together in order to treat any of the disorders or diseases mentioned above.
1. A method of treating obesity in a patient, said method comprising: passing an elongated implement into the esophagus of the patient, and into the cavity of the stomach of the patient, wherein a proximal end portion of the implement extends outside of the patient when a distal end of the implement is located in the stomach cavity; forming an opening through the wall of the stomach; passing a device, in a contracted configuration, into the esophagus, into the stomach and through the opening through the wall of the stomach, thereby delivering the device to an extra-gastric location in the abdominal cavity; expanding the device; urging the device against the external wall of the stomach.
2. The method of claim 1, further comprising attaching the device at least one location to at least one internal abdominal structure other than the stomach.
3. The method of claim 1, wherein said expanding comprises inflating the device via a conduit in fluid communication with the device and extending into the stomach, through the esophagus and out of the mouth of the patient.
4. The method of claim 1, further comprising extending a connector through the implement, and into the stomach, so that a distal end of the connector extends out through the stomach wall and into the abdominal cavity and a proximal end of the connector extends proximally out of the implement, outside of the patient.
5. The method of claim 4, wherein the device is delivered in combination with the connector during said passing a device.
6. The method of claim 1, further comprising passing an anchor pad or strip into the esophagus and stomach of the patient, through the opening of the stomach, and attaching the anchor pad or strip to an internal abdominal structure, and wherein the device includes a region configured to connect with the anchor pad or strip, said method further comprising, after said passing the device, attaching the anchoring pad or strip to the anchor pad or strip.
7. A method of treating obesity in a patient, said method comprising: making an opening through a wall of the stomach of the patient; passing an expandable device, while in a contracted configuration, through the opening from a location within the cavity in the stomach to a location external of the stomach wall, without substantially deforming the stomach wall; expanding the expandable device; and anchoring the expandable device against an inner surface of the stomach wall, opposite a location of the expandable device adjacent an outer surface of the stomach wall.
8. The method of claim 7, further comprising anchoring the expandable device, relative to at least one additional structure in the abdominal cavity.
9. The method of claim 7, wherein the step of expanding the expandable device causes the device to occupy a space into which the stomach would expand if the device were not expanded there, and wherein the step of expanding the expandable device does not substantially deform the wall of the stomach during said expanding the expandable device.
10. The method of claim 7, wherein said anchoring the expandable device against an inner surface of the stomach wall comprises attaching an adjustment member to a conduit passing through the opening.
11. A flexible conduit for trans-oral delivery of a device into an abdominal cavity of a patient, said conduit comprising: an elongated, flexible tube having a length sufficient to be inserted into the esophagus of the patient, into the stomach of the patient and through an opening formed through the wall of the stomach such that a distal end portion of the tube extends out of the stomach an into the abdominal cavity, and a proximal end portion at the same time extends proximally outside of the patient; and at least one radially expandable anchor on a distal end portion of said tube.
12. The flexible conduit of claim 11 wherein said flexible tube further comprises: a pair of radially extensible anchors, a more distal of said pair of anchors configured to abut against an intra-abdominal structure other than the stomach, and a more proximal of the pair of anchors configured to abut against the inner wall of the stomach, such that said anchors fix a distal end portion of said sheath relative to the stomach wall.
13. The flexible conduit of claim 12 wherein said pair of radially extensible anchors are independently moveable with respect to one another and tension between them can be controlled by applying tension to said flexible tube.
14. The flexible conduit of claim 12 wherein at least one of said pair of radially extensible anchors are attached to a connector.
15. The flexible conduit of claim 11 wherein said radially extensible anchor is attachable such that is exerts a compressive force on the stomach during stomach distention.
16. The flexible conduit of claim 11 wherein said extensible anchor is fillable with a fluid.
Filed: Jul 6, 2008
Publication Date: Nov 6, 2008
Inventor: Michael Gertner (Menlo Park, CA)
Application Number: 12/168,134
International Classification: A61B 17/12 (20060101);