Abstract:
A gastro-intestinal tube placement device for percutaneously placing gastro-intestinal tubes into the gastric cavity. The gastro-intestinal tube placement device of the present invention includes a containment element, such as an overtube, through which a gastro-intestinal tube can pass, and a displacing element assembly for pushing a gastro-intestinal tube through the containment element. The present invention also includes a gastro-intestinal tube having a collapsible internal bolster at its distal end, which bolster is capable of being manipulated to have a reduced lateral extent that allows the tube to be placed within the containment element.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to an apparatus for use in the placement of gastro-intestinal devices. More specifically, the present invention relates to a gastro-intestinal tube placement device which includes a tube deployment apparatus and a gastro-intestinal tube with a collapsible internal bolster. 
     BACKGROUND OF THE INVENTION 
     Medical practitioners utilize a variety of gastro-intestinal devices to access the gastro-intestinal tract. One type of gastro-intestinal device, the gastro-intestinal tube or gastrostomy tube, is widely used with patients who require catheterization for the purposes of, for example, delivering food or medication to the gastro-intestinal tract, draining the tract, or creating a surgical port. 
     Medical practitioners often use Percutaneous Endoscopic Gastrostomy (PEG) techniques, such as those described in U.S. Pat. Nos. 4,861,334; 4,900,306; and 5,080,650, to place tubes within the gastro-intestinal tract. These techniques typically involve either placing a gastro-intestinal tube in the patient&#39;s mouth and snaking it down the esophagus, into the stomach, and out the abdominal wall, or they involve inserting a tube into the stomach from outside of the abdominal wall by sliding the tube over a guidewire. 
     Gastro-intestinal tubes are often equipped with internal bolsters, or anchoring devices, at one end which help prevent the tube from being prematurely or inadvertently pulled through the stoma or other tract through which it has been placed. While serving that purpose, the size, shape and rigidity of these bolsters often frustrate attempts to place tubes equipped with such bolsters using PEG techniques. 
     When the tube is properly placed, the internal bolster lies inside the stomach wall, and the tube shaft extends out through the abdominal wall. Thus, when using PEG placement techniques which entail snaking the tube into place, the internal bolster is dragged along with the tube through the gastro-intestinal tract, often causing tissue trauma and potential contamination of the tract. Further, internal bolsters are often too large and rigid to allow placement by threading a bolster-equipped tube through a tract over a guidewire. 
     The internal bolsters also make tube removal difficult. Because the bolsters are often too large and rigid to allow easy removal by, for example, traction pull from outside the stomach, tubes with internal bolsters are often removed with an endoscopic snare. 
     SUMMARY OF THE INVENTION 
     The present invention provides a gastro-intestinal placement device which permits placement, through an existing stoma, of a gastro-intestinal tube with an internal bolster. The invention includes a gastro-intestinal tube with a collapsible internal bolster and a tube deployment device. 
     In the preferred embodiment, the deployment device has a containment element, such as an overtube, with an expandable distal tip and a slot through which the shaft of a gastro-intestinal tube can be threaded. The deployment device can be preloaded with the gastro-intestinal tube to form the placement device. The tube is loaded into the deployment device by collapsing or otherwise reducing the lateral extent of the tube&#39;s bolster, placing the bolster inside of the overtube at the overtube&#39;s distal end, and threading the shaft of the gastro-intestinal tube out through the slit in the overtube. 
     In that embodiment, the deployment device also has a displacing element, such as a pushtube, which is used to force the bolster out of the distal end of the overtube. In addition, the deployment device has a thumb-ring attached to the pushtube which facilitates moving the pushtube distally during tube placement. The deployment tube also has a spool at the proximal end of the overtube which provides physicians with a base on which to place their fingers and steady the deployment device during tube placement. The gastro-intestinal tube preferably has a collapsible bolster of umbrella-like design with retention ribs connected by cross-webbing. The bolster is preferably formed with memory of the umbrella-like shape. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be more readily understood through the following detailed description, with reference to the accompanying drawings, in which: 
     FIG. 1 is a perspective view, partially in section, of the preferred embodiment of the present invention, showing a gastro-intestinal tube placed partially within a gastro-intestinal tube deployment device, which tube has a collapsible bolster at its distal end that has been deployed. 
     FIG. 2 is a top cross-sectional view of an embodiment of the present invention, showing a gastro-intestinal tube placed partially within a gastro-intestinal tube deployment device, in which the collapsible bolster is shown in its expanded state protruding out from the distal end of the tube. 
     FIG. 3 is an elevational cross-sectional side view of the present invention, showing a gastro-intestinal tube placed partially within a gastro-intestinal tube deployment device, in which the collapsible bolster is shown in its expanded state protruding out from the distal end of the tube. 
     FIG. 4 is a perspective view of a gastro-intestinal tube of the present invention. 
     FIG. 5 is a perspective view of an overtube component of a gastro-intestinal tube deployment device according to the present invention. 
     FIG. 6 is a perspective view of a spool component of a gastro-intestinal tube deployment device according to the present invention. 
     FIG. 7 is a perspective view of a pusher component of a gastro-intestinal tube deployment device according to the present invention. 
     FIG. 8 is a perspective view of a plug component of a gastro-intestinal tube deployment device according to the present invention. 
     FIG. 9 is an elevational view of a second embodiment of a gastro-intestinal tube deployment device according to the present invention. 
     FIG. 10 is a perspective view of an internal bolster according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The preferred embodiment of the gastro-intestinal tube deployment device  1  of the present invention is shown in FIG.  1 . That device is made of several components: a gastro-intestinal tube  14 , a pusher assembly  28 , a spool  20 , and a plug  30 . Each of those components is shown separately in FIGS. 4-8, respectively. FIG. 1 shows the assembled gastro-intestinal tube deployment device  1  of the present invention. 
     The assembled placement device  1  allows a physician to place a gastro-intestinal tube which has a collapsible internal bolster easier than if the physician used prior art methods and devices. During the deployment procedure, the placement device  1  is inserted through a path through which the gastro-intestinal tract can be reached. The path can be created by, for example, a stoma, a surgical port or a cannula. Any path which allows passage of the placement device  1  from outside of a patient&#39;s body to any location within the gastro-intestinal tract will suffice. For ease of discussion, however, reference will hereinafter be made to a path to the stomach via stoma. 
     Prior to tube placement, the physician can snake an endoscope into the patient&#39;s stomach so that the insertion site can be viewed during placement. The physician can then see the point at which the placement device  1  is properly inserted through the stoma. Once the placement device  1  is properly inserted, the pusher  16  is moved distally to push the collapsible bolster  10  past the distal end  2  of the placement device  1 . Once so pushed, the bolster  10  deploys to its extended state, as shown in FIG.  1 . The deployment device  1  can then be pulled from the stoma. 
     As the device  1  is pulled proximally, the deployed bolster  10  serves as an anchor inside the stomach wall, preventing the tube  14  from being pulled out through the stoma. During removal of device  1 , the portion of shaft  44  of the gastro-intestinal tube  14  which was threaded out through the opening  26  in the overtube  12 , is pulled in through the opening  26  and out the distal end  2  of the device  1 . Once the placement device  1  is removed, the gastro-intestinal tube  14  is left in place inside the stomach. 
     The spool  20  and the thumb-ring  24  facilitate tube placement by providing sites for the physician to place his fingers. During placement, the physician places two fingers on the spool  20 , on opposite sides of the spool  20  between the distal ridge  38  and the proximal ridge  40 , and places his thumb in the thumb-ring  24 . The physician then uses his thumb to push distally on the thumb-ring  24 , which is connected to the pusher  16 . 
     FIG. 4 shows a gastro-intestinal tube  14  with a collapsible internal bolster  10  at its distal end and a tube shaft  44 . The collapsible internal bolster  10  can be folded, deformed or otherwise reduced in lateral extent so as to allow the bolster  10  and the distal end of the tube  14  to be preloaded into the overtube  12 . When loaded, the collapsible bolster  10  and a portion of the distal end of the tube shaft  44  lie within the overtube  12 . The remaining length of the tube shaft  44  is threaded out of the overtube  12  through an opening  26 , as shown in FIG.  1 . 
     The overtube  12 , shown in FIG. 5, is a tubular structure with an expandable distal end  50  and an opening  26 . The central lumen of the overtube  12  is capable of housing the gastro-intestinal tube  14  being placed and the pusher  16 . The overtube  12  serves as the conduit through which the gastro-intestinal tube is placed. During tube placement, the pusher  16  is moved distally, forcing the tube&#39;s bolster  10  out of the overtube&#39;s distal end. 
     The expandable distal tip  50  of the overtube  12  expands to facilitate passage of the tube bolster  10  out of the overtube. The overtube depicted in FIG. 5 has slits  52  which form petals  54 . During deployment of the bolster (i.e. pushing the bolster  10  out of the distal end of the overtube  12 ) the petals  54  are forced outward and apart, allowing easy passage of the bolster out of the overtube  12 . 
     Although the overtube  12  is preferably formed with slits  52 , the overtube  12  need not be so formed. The distal tip  50  can be made expandable in many ways. For example, the distal tip  50  can be formed with overlapping folds or with a web structure having petals and flexible material between the petals. In addition, the overtube can be made without an expandable distal tip  50 . Although the expandable tip  50  facilitates tube placement, the tube bolster  10  can be forced out of the distal end of an overtube that does not have such a tip. 
     As shown in FIG. 6, the spool  20  of the placement device  1  is a tube-like structure with a central lumen, a distal ridge  38  and a proximal ridge  40 . The spool  20  fits over the overtube  12  at the proximal end of the device assembly  1 . As shown in FIG. 5, the overtube  12  can have distal and proximal stops,  46  and  48  respectively, which hold the spool  20  in place. In addition, the overtube  12  and spool  20  can be held together by a plug  30 , shown in FIG.  8 . The plug  30  is placed through bore holes  36  in the overtube  12  and bore holes  42  in the spool. The plug  30  keeps the spool  20  from moving with respect to the overtube  12 . 
     The pusher  16 , shown in FIG. 7, is a rod which runs through the overtube  12 , allowing the physician to push the bolster  10  out of the distal end of the overtube  12 . The pusher  16  preferably has a ring  52  at its distal end which fits around the shaft  44  of the gastro-intestinal tube  14  at the base of the bolster  10 . With the ring  52 , the force of the distally-moving pusher  16  is applied to the circumference of the bolster&#39;s base. Alternatively, the pusher can be a straight rod. In addition, other components can be attached to the pusher rod  16 , to form a pusher assembly (an example of which is shown in FIG.  1 ). The pusher assembly shown in FIG. 1 includes a thumb-ring attached to its proximal end. 
     FIGS. 2 and 3 show top cross-sectional and elevational cross-sectional side views, respectively, of the first embodiment of the gastro-intestinal tube placement device of the present invention. 
     Another embodiment of the gastro-intestinal tube placement device  2  of the present invention is shown in FIG.  9 . In that embodiment, the pusher is a rod which slides inside the overtube  64 . The overtube finger flange  60  provides a base for the physician&#39;s fingers, much like the spool  20 , of the previous embodiment. The push tube press  56  provides a base against which the physician can push during placement. The physician can push on the press  56  with either the thumb or the palm of his hand. 
     FIG. 10 shows a collapsible internal bolster  10  which is used with the device described above. Although it can be appreciated that any internal bolster may be used which can be collapsed, compressed or otherwise reduced in lateral extent to allow loading within the overtube, the embodiment shown in FIG. 10 is preferred. 
     The bolster  10  has an umbrella-like design in which retention ribs  70  are connected by cross-webbing  72 . Both the ribs  70  and cross-webbing can be made of silicone copolymers or other plastic. The cross-webbing  72  is sufficiently thin that it folds when the ribs  70  are pushed distally and towards the longitudinal axis of the tube  14 . The cross-webbing  72  is preferably formed with predetermined fold lines  76 , and thinned areas  74  near the base of the bolster  10 . The fold lines  76  and thinned areas  74  permit the cross-webbing  72  to fold in a predetermined manner. 
     The bolster  10  is preferably manufactured with memory for the umbrella-like shape (i.e. the shape that the bolster  10  will have in its un-compressed state inside the stomach). Thus, once bolster  10  is pushed past the distal end of the overtube  12 , the bolster returns to its predetermined umbrella-like shape. In this predetermined shape, the bolster anchors the tube within the stomach. When more than a threshold amount of proximally-directed force is applied, however, the bolster will collapse, allowing removal by traction pull. 
     The bolster  10  is preferably made of a soft plastic that is capable of maintaining memory, such as silicone, a polyurethane or ethylene vinyl acetate. In addition, the bolster  10  is preferably about 1 inch in diameter and 1 inch from its distal-most point to its most proximal point. Those dimensions can change, however, depending on the plastic material utilized. When more rigid plastic material is used, the dimensions can be smaller. When a less rigid plastic material is used, the dimensions may need to be larger.