Abstract:
A gastric reduction system and method provides for transesophageal formation of a gastric reduction pouch of the stomach. The system includes an expandable structure, which may be placed in a stomach and expanded to occupy a fractional volume of the stomach. An evacuator is then fed through the expandable structure and utilized to deflate the stomach and draw the stomach to and around the expandable structure to form the gastric reduction pouch. A self-deploying fastener is then deployed to maintain the gastric reduction pouch.

Description:
This application is a continuation application of application Ser. No. 10/686,427, filed on Oct. 14, 2003 now abandoned. The entire disclosure of which is hereby incorporated by reference for all purposes. 
    
    
     FIELD OF THE INVENTION 
     The present invention is generally directed to a therapy for treating obesity. The present invention is more particularly directed to a transesophageal gastric reduction device, system, and method for performing gastric reduction surgery while minimizing surgical invasion. 
     BACKGROUND OF THE INVENTION 
     Obesity is a complex chronic disease involving environment, genetic, physiologic, metabolic, behavioral and psychological components. It is the second leading cause of preventable death in the United States. 
     Obesity affects nearly one-third of the adult American population (approximately 60 million). The number of overweight and obese Americans has continued to increase since 1960. The trend is not slowing down. Today, 64.5% of adult Americans are categorized as being overweight or obese. Each year, obesity causes at least 300,000 excess deaths in the United States, and healthcare costs of American adults with obesity amounted to approximately $100,000,000,000 (100 billion dollars). 
     Obesity is not limited to the United States but is increasing worldwide. It is increasing worldwide in both developing and developed countries and is thought to be caused by environmental and behavioral changes resulting from economic development, modernization, and urbanization. Obesity is increasing in children as well. It is believed that the true health consequences of obesity have not yet become totally apparent. 
     Obesity is currently treated by dietary therapy, physical activity, behavioral therapy, drug therapy, and combinations thereof. Dietary therapy involves instruction on how to adjust a diet to reduce the number of calories eaten. Physical activity strategies include use of aerobic exercise, brisk walking, jogging, cycling, and swimming. Behavioral therapy involves changing diet and physical activity patterns and habits to new behaviors that promote weight loss. Drug therapy is most often used only in conjunction with appropriate lifestyle modifications. 
     One last treatment for obesity is surgery. Surgery is a treatment option which is generally reserved for persons with severe obesity and those who are morbidly obese. In addition, surgery is not generally performed until other methods of weight loss have been attempted and have been found to be ineffective. Persons who are severely obese are generally unable to physically perform routine daily activities, whether work-related or family functions and have a severely impaired quality of life due to the severity of their obesity. 
     Most obesity surgeries involve making changes to the stomach and/or small intestines. Currently, there are two types of obesity surgery: (1) restrictive; and (2) combined restrictive and malabsorptive. Operative procedures have been developed for each type of surgery. Each type of surgery has its own risks and side effects. 
     In restrictive surgery, bands or staples are used to create food intake restriction. The bands or staples are surgically placed near the top of the stomach to section off a portion that is often called a stomach pouch. A small outlet, about the size of a pencil eraser, is left at the bottom of the stomach pouch. Since the outlet is small, food stays in the pouch longer and the feeling of fullness lasts for a longer time. Current operative procedures for restrictive surgery include vertical banded gastroplasty, gastric banding, and laparoscopic gastric banding. In vertical banded gastroplasty, a stomach pouch is surgically created. In gastric banding, a band is used to create the stomach pouch. In laparoscopic gastric banding, a less invasive procedure, smaller incisions are made to apply the band. The band is inflatable and may be adjusted over time. 
     Each of the foregoing therapies for severe obesity has its risks and side effects. Each is invasive surgery and hence exhibits the risks commonly associated with all surgical procedures. Complications may include leaking of stomach juices into the abdomen, injury to the spleen, band slippage, erosion of the band, breakdown of the staple line, and stomach pouch stretching from overeating. 
     However, reductive surgery has proven successful. About 80% of patients lose some weight and 30% reach a normal weight. Hence, the benefits of gastric reduction surgery are generally believed to outweigh the attendant risks and potential complications. 
     The present invention is directed to an alternative device, system, and method for achieving gastric reduction. As will be seen hereinafter, the device, system, and method do not require surgical incisions and is thus less invasive than previous reduction therapies. 
     SUMMARY OF THE INVENTION 
     The invention generally provides a gastric reduction device comprising an expandable structure placeable in a stomach which, when expanded, occupies a portion of the stomach and an evacuator that deflates the stomach around the expandable structure to form a gastric reduction pouch. The expandable structure is preferably placeable in the stomach immediately adjacent and distal to an esophageal orifice associated with the stomach. 
     The expandable structure may comprise a balloon. The evacuator may extend distally from the expandable member and terminate within the stomach. 
     The device may further comprise a fastener that maintains the gastric reduction pouch. The fastener is preferably arranged to inwardly fold stomach tissue to fasten serosa tissue to serosa tissue of the stomach. The fastener may comprise a cylindrically shaped member having opposed ends and tissue engaging arms radially extending from each of the opposed ends. 
     The device may further comprise an endoscope that extends through the expandable member. The expandable member preferably forms a spherically shaped ring when expanded. The spherically shaped ring may include an axial passageway permitting the evacuator to extend through the passageway. 
     The present invention still further provides a gastric reduction system comprising an expandable structure, placeable in a stomach, and, when expanded, occupying a fractional volume of the stomach. The system further includes an evacuator that deflates the stomach and draws the stomach to and around the expandable member to form a gastric reduction pouch with stomach tissue and a fastener that is operable to maintain the gastric reduction pouch. The fastener may be carried by the evacuator. 
     The present invention still further provides a method comprising the steps of positioning an expandable structure in a stomach of a patient, expanding the expandable structure to occupy a portion of the stomach, and drawing the stomach around the expandable structure to form a gastric reduction pouch. The positioning step may include placing the expandable structure immediately distal to an esophageal orifice associated with the stomach. The expandable structure may comprise a balloon and the expanding step may include inflating the balloon. 
     The deflating step may include evacuating the stomach. To this end, an evacuator may be fed into the stomach. The evacuator may be fed into the stomach through the expandable structure. 
     The method may further include the step of maintaining the gastric reduction pouch. Maintaining the gastric reduction pouch may include inwardly folding stomach tissue to contact serosa tissue to serosa tissue to form a stoma. The inwardly folded stomach tissue may be fastened together. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with further features and advantages thereof, may best be understood by making reference to the following description taken in conjunction with the accompanying drawings, in the several figures of which like reference numerals identify identical elements, and wherein: 
         FIG. 1  is a front cross-sectional view of the esophageal-gastro-intestinal tract from a lower portion of the esophagus to the duodenum; 
         FIG. 2  is a perspective view with portions cut away of a device embodying the present invention; 
         FIG. 3  is a perspective view with portions cut away of the device of  FIG. 2  illustrating partial deployment of a fastener in accordance with the present invention; 
         FIG. 4  is a perspective view with portions cut away of the device of  FIG. 2  with the fastener in a further stage of deployment; 
         FIG. 5  is a cross-sectional view of an esophagus and stomach with a device embodying the present invention in an initial stage of gastric reduction therapy in accordance with the present invention; 
         FIG. 6  is a cross-sectional view similar to  FIG. 5  of the device in a further stage of the therapy; 
         FIG. 7  is a cross-sectional view similar to  FIG. 5  of the device delivering a fastener in a still further stage of the therapy; 
         FIG. 8  is a cross-sectional view similar to  FIG. 5  of the device and fastener in a final stage of the therapy; and 
         FIG. 9  is a cross-sectional view similar to  FIG. 5  after completion of the therapy and removal of the device embodying the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a front cross-sectional view of the esophageal-gastro-intestinal tract  40  from a lower portion of the esophagus  41  to the duodenum  42 . The stomach  43  is characterized by the greater curvature  44  on the anatomical left side and the lesser curvature  45  on the anatomical right side. The tissue of the outer surfaces of those curvatures is referred to in the art as serosa tissue. As will be seen subsequently, the nature of the serosa tissue is used to advantage for its ability to bond to like serosa tissue. The fundus  46  of the greater curvature  44  forms the superior portion of the stomach  43 , and traps gas and air bubbles for burping. The esophageal tract  41  enters the stomach  43  at an esophageal orifice  58  below the superior portion of the fundus  46 , forming a cardiac notch  47  and an acute angle with respect to the fundus  46  known as the Angle of His  57 . The lower esophageal sphincter (LES)  48  is a discriminating sphincter able to distinguish between burping gas, liquids, and solids, and works in conjunction with the fundus  46  to burp. The gastroesophageal flap valve (GEFV)  49  includes a moveable portion and an opposing more stationary portion. The moveable portion of the GEFV  49  is an approximately 180 degree, semicircular, gastroesophageal flap  50  (alternatively referred to as a “normal moveable flap” or “moveable flap”) formed of tissue at the intersection between the esophagus  41  and the stomach  43 . The opposing more stationary portion of the GEFV  49  comprises a portion of the lesser curvature  45  of the stomach  43  adjacent to its junction with the esophagus  41 . The gastroesophageal flap  50  of the GEFV  49  principally comprises tissue adjacent to the fundus  46  portion of the stomach  43 , is about 4 to 5 cm long ( 51 ) at it longest portion, and the length may taper at its anterior and posterior ends. The gastroesophageal flap  50  is partially held against the lesser curvature  45  portion of the stomach  43  by the pressure differential between the stomach  43  and the thorax, and partially by the resiliency and the anatomical structure of the GEFV  49 , thus providing the valving function. The GEFV  49  is similar to a flutter valve, with the gastroesophageal flap  50  being flexible and closeable against the other more stationary side. 
     The esophageal tract is controlled by an upper esophageal sphincter (UES) near the mouth for swallowing, and by the LES  48  and the GEFV  49  at the stomach. The normal anti-reflux barrier is primarily formed by the LES  48  and the GEFV  49  acting in concert to allow food and liquid to enter the stomach, and to considerably resist reflux of stomach contents into the esophagus  48  past the gastroesophageal tissue junction  52 . Tissue aboral of the gastroesophageal tissue junction  52  is generally considered part of the stomach because the tissue protected from stomach acid by its own protective mechanisms. Tissue oral of the gastroesophageal junction  52  is generally considered part of the esophagus and it is not protected from injury by prolonged exposure to stomach acid. At the gastroesophageal junction  52 , the juncture of the stomach and esophageal tissues form a zigzag line, which is sometimes referred to as the “Z-line.” For the purposes of these specifications, including the claims, “stomach” means the tissue aboral of the gastroesophageal junction  52 . 
       FIG. 2  shows a device  60  embodying the present invention. As will be seen hereinafter, the device  60  permits transesophageal gastric reduction for treating severe obesity. The device  60  generally includes an expandable structure  70  and an evacuator  80 . Shown further in  FIG. 2  is a fastener  90  which the device  60  delivers to maintain a formed gastric reduction pouch. 
     The expandable structure  70 , in accordance with this embodiment, takes the form of an inflatable ring-shaped balloon  72  which is integrally formed on and carried by an outer catheter  74 . The ring-shaped balloon  72  and catheter  74  define an axial passageway  76 . The balloon may be a compliant balloon formed of latex or polyurethane, for example. It may alternatively be a non-compliant balloon formed of polyethylene. A non-compliant balloon may be preferred as it maintains a fixed shape and size once totally inflated rendering the size of the balloon is rendered predictable. 
     The evacuator  80 , in accordance with this embodiment, comprises an endoscope  82  which includes a light source  84 , a viewer  86 , and a working channel  88 . Endo scopes of this type are well known in the art. The working channel  88  is employed for evacuating the stomach once the device  60  is in place within the stomach and the balloon  72  has been inflated. This will become more apparent subsequently. 
     As will be noted in  FIG. 2 , the evacuator  80  extends through the expandable structure  70 . More specifically, the endoscope  82  may be advanced through the axial passageway  76  to terminate distal to the expandable structure  70  to facilitate the evacuation of the stomach. The fastener  90  may be carried by the endo scope  82  and also advanced through the axial passageway  76  along the endoscope  82  by a tubular pusher  100 . 
     The fastener  90  is preferably formed of a shape memory material such as Nitinol or a shape memory plastic, for example, so as to be self-deploying when advanced past the distal end  78  of the catheter  74 . It alternatively may be formed of stainless steel but would then require forced expansion as, for example, a balloon as is well known in the art.  FIG. 3  illustrates the fastener  90  during an initial stage of its deployment. The fastener  90  prior to its deployment takes the form of a cylindrically shaped member  92  having opposed ends from which first and second sets of tissue engaging arms radially extend after deployment. As will be noted in  FIG. 3 , a first set of tissue engaging arms  93  are radially extending from the cylindrical member  92  as the fastener  90  is advanced by the catheter  100  past the distal end  78  of the catheter  74 . Upon further displacement of the fastener  90  as illustrated in  FIG. 4 , the cylindrical center portion of the cylindrical member  92  is exposed. This forms a channel through which ingested food may pass out of the gastric reduction pouch after it is formed and maintained by the fastener  90 . 
     Referring now to  FIG. 5 , it illustrates an initial stage of forming the gastric reduction pouch in accordance with the present invention. Here it will be seen that the expandable structure  70  has been advanced through the esophagus  41  on the catheter  74  so that it is placed in the stomach immediately adjacent and distal to the esophageal orifice  58 . After the expandable member is positioned adjacent the esophageal orifice  58 , the endo scope  82  is advanced through the axial passageway of the catheter  74  and expandable structure  70  until it is distal to the catheter  74  and expandable structure  70  within the stomach  43 . 
     After the expandable structure  70  and endo scope  82  are placed in the stomach  43  as illustrated in  FIG. 5 , the expandable structure  70  is expanded to define the size and shape of the gastric reduction pouch to be formed. In accordance with this preferred embodiment, the expandable structure  70  comprises a balloon  72  which may be inflated as illustrated in  FIG. 6 . Here it may be seen that the balloon  72  has been inflated and occupies a fraction or portion of the stomach  43 . The balloon  72  may be inflated through a lumen (not shown) in the catheter  74  in a manner well known in the art. 
     After the balloon  72  has been expanded to its desired size, the stomach  43  is evacuated through the working channel of the endoscope  82  to cause the stomach to be drawn around the balloon  72 . 
     Once the stomach tissue has been drawn around the balloon  72 , the fastener  90  is then advanced down the endoscope  82  by the pusher  100  for deploying the fastener  90 . As shown in  FIG. 7 , the fastener  90  is partially deployed with the first set of tissue engaging arms  93  radially extending from the cylindrical body  92  of the fastener  90 . Upon further advancement of the fastener  90  as illustrated in  FIG. 8 , the second set of tissue engaging arms  95  are released from the catheter  74  to radially extend from the cylindrical body  92  of the fastener  90 . 
     The shape memory of the fastener  90  may be used to advantage by which the opposed sets of radially extending tissue engaging arms  93  and  95  together with the drawing of the stomach around the balloon  72  inwardly folds the outer surfaces of the stomach  43  to cause contact between adjacent outer surfaces of the stomach about the cylindrical body  92  of the fastener  90 . The outer surface of the stomach comprises serosa tissue which develops a bond after contacting like tissue within a short period of time. This bond between the outer surfaces of the contacting stomach tissue will assist the fastener  90  in maintaining the gastric reduction pouch thus formed. 
     Once the fastener  90  has been fully deployed as illustrated in  FIG. 8 , the assembly and device  60  is removed from the stomach. This may be achieved by first drawing the pusher  100  out of the catheter  74 . Then, the balloon  72  may be deflated permitting the balloon  72  and catheter  74  to be withdrawn from the stomach on the endoscope  82 . Lastly, the endoscope  82  may be withdrawn through the fastener  90 , through the gastric reduction pouch formed by the assembly and device  60 , and the esophagus  41 . This leaves the esophageal-gastro-intestinal tract  40  in a condition as illustrated in  FIG. 9 . Here it may be seen that the gastric reduction pouch  110  has been formed between the esophagus  41  and the remaining stomach  43 . The fastener  90  may remain in place to maintain the gastric reduction pouch  110 . The gastric reduction pouch  110  presents a smaller volume to accommodate ingested food thus providing the patient with an earlier sense of being full and a longer time of feeling full. 
     As will be noted from the foregoing, the process of forming the gastric reduction pouch  110  with the device  60  embodying the present invention has been performed in a transesophageal manner without the need of any surgical incisions. Hence, the therapy contemplated herein is much less invasive than previous therapies for providing gastric reduction therapy. All of the advantages of gastric reduction therapy are available while substantially reducing the risks attendant to general surgery. 
     While particular embodiments of the present invention have been shown and described, modifications may be made, and it is therefore intended in the appended claims to cover all such changes and modifications which fall within the true spirit and scope of the invention.