Patent Publication Number: US-2012029652-A1

Title: Apparatuses and methods for implanting gastrointestinal stents

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to copending U.S. provisional application entitled, “Apparatuses And Methods For Implanting Gastrointestinal Stents,” having Ser. No. 61/165,599, filed Apr. 1, 2009, which is entirely incorporated herein by reference. 
    
    
     BACKGROUND 
     Stents are used in various lumens within the body. For example, it is now common to implant stents within the coronary arteries during angioplasty procedures. Stents are now also used within the digestive system. For example, stents are implanted within the esophagus, duodenum, bile duct, pancreatic duct, and the colon. 
     There are other lumens within the body in which stents could be useful. For example, stents could be placed within the small intestine to correct gastrointestinal obstructions or fistulas. At present, however, small intestine stent implantation is not routinely performed due to the difficulty in achieving endoscopic access to the small intestine via enteroscopy. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The present disclosure may be better understood with reference to the following figures. In the figures, like reference numerals designate corresponding parts throughout the figures, which are not necessarily drawn to scale. 
         FIGS. 1A-1E  are schematic views of a patient and his digestive system, and illustrate steps of a small intestine stent implantation procedure performed via a natural orifice. 
         FIGS. 2A and 2B  are side and end views, respectively, of a first embodiment of an integrated surgical device that can be used in the procedure illustrated in  FIGS. 1A-1E . 
         FIGS. 3A-3H  are schematic views of translumenal access of the small intestine for purposes of stent deployment using the surgical device shown in  FIGS. 2A and 2B . 
         FIGS. 4A and 4B  are side and end views, respectively, of a second embodiment of an integrated surgical device that can be used in the procedure illustrated in  FIGS. 1A-1E . 
     
    
    
     DETAILED DESCRIPTION 
     Disclosed herein are apparatuses and methods for implanting a stent within the gastrointestinal tract. More particularly, disclosed are apparatuses and methods for implanting a stent within the small intestine, also referred to as the small bowel. In the disclosed methods, the small intestine is accessed using a natural orifice as an entry point. In some embodiments, the peritoneal cavity is first accessed via the stomach, colon, or vagina and the small intestine is then entered translumenally. In some embodiments, entry into the small intestine and deployment of the stent therein is achieved using a single integrated surgical device that includes a cutting element, a guidewire, a dilator, and a stent deployment device. Although particular embodiments of apparatuses and methods are disclosed herein, it is noted that those embodiments are mere implementations of the disclosed inventions and that alternative embodiments are both possible and intended to fall within the scope of the present disclosure. 
       FIG. 1A  schematically illustrates a patient  10  and his digestive system  12 , including the mouth  14 , the esophagus  16 , the stomach  18 , the small intestine  20 , the large intestine  22 , the rectum  24 , and the anus  26 . For purposes of this disclosure, it is assumed that there is a medical condition, such as an obstruction or fistula (not illustrated) within the small intestine  20 , that could be alleviated by stent implantation. To avoid the difficulty of achieving endoscopic access to the small intestine via enteroscopy, transluminal endoscopic surgery is performed using a natural orifice as the point of entry. Such procedures are occasionally referred to as “natural orifice translumenal endoscopic surgery” or “NOTES” procedures. In the example that follows, the natural orifice that is chosen is the mouth (and esophagus). It is noted, however, that another natural orifice could instead be chosen, such as the colon or urethra or, in cases in which the patient is female, the vagina. 
     Referring next to  FIG. 1B , the shaft of an endoscope  28 , such as a flexible, manually articulable endoscope, is fed through the mouth  14  and the esophagus  16  until a distal tip  30  of the endoscope reaches the interior of the stomach  18 . The anterior wall of the stomach  18  is then identified by endoscopically viewing the indentation produced by external palpitation. With reference to  FIG. 1C , a full-thickness gastric incision  32  is made through the stomach wall using an appropriate cutting element  34 . In some embodiments, the cutting element  34  comprises an endoscopic cutting element that, as illustrated in  FIG. 1C , is passed through a lumen (e.g., working channel) of the endoscope  28  so that the incision can be made under direction endoscopic viewing. By way of example, the cutting element  34  comprises an electrocautery needle knife. 
     Once the incision  32  has been made, the endoscope  28  is passed through the incision and the stomach wall to achieve access to the peritoneal cavity. Transgastric endoscopic peritoneoscopy is then performed and the small intestine  20  is identified by direct endoscopic visualization. As shown in  FIG. 1D , the tip  30  of the endoscope  28  can then be maneuvered to a desired location of the small intestine  20 , again using direct endoscopic visualization. 
     Once the desired entry point of the small intestine  20  has been identified, an enterotomy can be performed to access the lumen of the small intestine, as illustrated in  FIG. 1E . In some cases, such access can be achieved using an integrated surgical device specifically designed for use in both accessing the small intestine lumen and deploying a stent within that lumen.  FIGS. 2A and 2B  illustrate a first embodiment of such a device  36 . As indicated in  FIG. 2A , the device  36  comprises an elongated flexible tube  38  (only a portion of which visible in the figure) that can be advanced through an endoscope, such as endoscope  28 . Comprised by the tube  38  is an integral stent deployment device  40  that includes a stent  42 . In some embodiments, the stent  42  comprises an initially-compressed, self-expanding metal stent (SEMS). Also comprised by the tube  38  is one or more radio-opaque markers  44 , such as a metal band, that can be used to identify the location and/or orientation of the device  36 , and its stent  42 , under fluoroscopy. 
     The integrated surgical device  36  further comprises a dilator  46  whose distal tip  48  forms the distal tip of the device. In the embodiment of  FIGS. 2A and 2B , the dilator  46  comprises a graduated frustoconical dilator. As described below, however, alternative types of dilators can be used. Also comprised by the device  36  is a cutting element  50  that can be selectively extended and retracted from the distal tip of the device. The cutting element  50  is shown in the extended orientation in  FIG. 2A . In some embodiments, the cutting element  50  comprises an electrocautery needle knife. Indeed, the cutting element  50  can, in some cases, be the electrocautery needle knife that was used to incise the stomach wall (see  FIG. 1C ). As shown in  FIG. 2A , the cutting element  50  comprises a sharp, beveled tip  52 . 
     The integrated surgical device  36  also includes a guidewire  54  that can be extended from the distal tip of the device. In the embodiment illustrated in  FIGS. 2A and 2B , the guidewire  54  is positioned within an inner lumen of the hollow cutting element  50  and therefore can be extended from the tip  52  of the cutting element. In alternative embodiments, however, the guidewire  54  need not be contained with the cutting element  50  (e.g., if the guidewire is too large to be passed through the cutting element or the cutting element is not hollow). In such a case, the guidewire  54  can be passed through an alternative lumen of the device  36  (not shown). Regardless, the guidewire  54  can comprise a coated steel and/or shape-memory alloy (e.g., nickel titanium) wire and a very flexible or “floppy” tip that facilitates traversal of the small intestine. In at least some embodiments, the guidewire  54  is preloaded within the device  36  to reduce the time necessary to perform the implantation procedure. 
       FIGS. 3A-3F  illustrate an example of use of the integrated surgical device  36  in preparation for stent deployment within a section of the small intestine  20 . Beginning with  FIG. 3A , the cutting element  50  is extended from the distal tip  48  of the device  36  and an electric current is applied to the element so that the element can easily cut a hole  56  through the wall  58  of the small intestine  20 . Once the hole  56  has been formed, the tip  48  of the device  36  can be passed through the hole and into the lumen  60  of the small intestine  20 , as shown in  FIG. 3B  (see also  FIG. 1E ). Notably, the size of the hole  56  is increased by the dilator  46  as the tip  48  is passed deeper into the lumen  60 . 
     Referring next to  FIG. 3C , the guidewire  54  is extended from the device  36  (e.g., from the tip  52  of the cutting element  50 ) and into the lumen  60 . As soon as a desired length of the guidewire  54  has been positioned within the lumen  60 , the cutting element  50  is retracted, as indicated in  FIG. 3D , to avoid unintended laceration of the small intestine wall  58 . Next, the device  36  is further advanced through the hole  56 , as shown in  FIGS. 3E and 3F , until the stent  42  is positioned at an appropriate location for deployment. If necessary, bowel loops can be manipulated with endoscopic forceps at any time during the procedure (not shown). At this point, the device  36  remains in the hole  56 , although its passage through the hole is not visible in  FIG. 3F  due to the advancement of the device through the lumen  60 . Once the integrated surgical device  36  is in the desired position, such as the position shown in  FIG. 3G , the stent  42  can be deployed within the small intestine lumen. By way of example, the elongated tube  38 , which serves as a sheath for the stent  42 , can be withdrawn to enable the stent to expand, as is schematically shown in the  FIG. 3H . Alternatively, the stent  42  can be advanced out from the tube  38  (not shown). 
     Assuming the stent  42  has been correctly deployed in the desired position within the small intestine  20 , the integrated surgical device  36  can be withdrawn, and the hole  56  that was formed in the small intestine can be closed. In some embodiments, the hole  56  can be closed using endoscopic clips. In other embodiments, the hole  56  can be sutured using a suitable endoscopic suturing device. After the hole  56  has been closed, the tip  30  of the endoscope  28  can be withdrawn back into the stomach  18  ( FIG. 1B ), and the stomach incision  32  can also be closed. 
     As can be appreciated from the foregoing description, a stent can be implanted within the small intestine using transluminal endoscopic surgery with entry via a natural orifice, thereby avoiding the need to perform small intestine enteroscopy or open surgery. When an integrated surgical device is used, time is saved because there is no need to exchange a cutting tool for a stent deployment device. In addition, because the cutting element and the stent deployment device are integrated into a single device, the size of the hole that must be made through the wall of the small intestine can be smaller, thereby facilitating easier closure and reducing patient risk. 
       FIGS. 4A and 4B  illustrate a second embodiment of an integrated surgical device  70  that can be used in the above-described procedure. The device  70  is similar in many ways to the device  36  shown in  FIGS. 2A and 2B . Therefore, as indicated in  FIG. 4A , the device  70  comprises an elongated flexible tube  72  (only a portion of which visible in the figure) that contains an integral stent deployment device  74 , which includes a stent  76 , and one or more radio-opaque makers  78 . The device  70  also includes a dilator  80 . However, unlike dilator  46 , the dilator  80  comprises an inflatable balloon dilator that can be expanded from an initial compressed orientation (not shown) when filled with an appropriate fluid (e.g., sterile water). The expanded state is illustrated in  FIGS. 4A and 4B . In addition, the device  70  includes an extendible/retractable cutting element  82  as well as an extendible guidewire  84  ( FIG. 4B ). 
     The integrated surgical device  70  can be used in similar manner to the integrated surgical device  36 . The primary difference between the two devices is that, with the device  70 , dilation of the hole formed by the cutting element  82  is achieved by expanding the balloon of the dilator  80  as opposed to urging a graduated dilator through the hole. 
     Although the disclosed surgical devices have been described as being well suited for transluminal endoscopic surgery and gastrointestinal stent placement, it is noted that the devices can be used for other purposes. For example, the surgical devices can be used in pancreatic pseudocyst drainage. In such a case, the device can be used to pass through the wall of the stomach or the small intestine to access a cyst formed on the pancreas. The device can be used to form an incision through the stomach or intestine wall and in the adjacent cyst wall, dilate the hole formed by the incision, place a stent within the pancreas cyst that extends to the stomach or intestine, and allow the cyst to drain into the stomach or small intestine. Accordingly, one device could be used to perform the tasks now performed by three independent devices. The stent can be left in place for a few weeks until the cyst is fully drained. At that point, the stent can be endoscopically removed.