Abstract:
The present disclosure provides an innovative retention element for use with feeding tubes for placement in a gastric lumen, desirably under direct visualization using an endoscope. The retention balloon has a shape with a recessed or concave center that provides space to accommodate the distal end of inserted feeding tubes. The retention balloon may be conical, square and half spherical and holds the stomach against the inner abdominal wall.

Description:
This application claims priority from U.S. Provisional Application 61/707,318 filed on Sep. 28, 2012. 
    
    
     The present disclosure relates to catheters such as feeding tubes and their placement in the body of a patient. 
     Numerous situations exist in which a body cavity needs to be catheterized to achieve a desired medical goal. One relatively common situation is to provide nutritional solutions or medicines directly into the stomach or intestines. A stoma is formed in the stomach or intestinal wall and a catheter is placed through the stoma. This surgical opening and/or the procedure to create the opening is commonly referred to as “gastrostomy”. Feeding solutions can be injected through the catheter to provide nutrients directly to the stomach or intestines (known as enteral feeding). A variety of different catheters intended for enteral feeding have been developed over the years, including some having a “low profile” relative to the portion of the catheter which sits on a patient&#39;s skin, as well as those having the more traditional or non-low profile configuration. These percutaneous transconduit catheters (sometimes referred to as “percutaneous transconduit tubes”) are frequently referred to as “gastrostomy catheters”, “percutaneous gastrostomy catheters”, “PEG catheters” or “enteral feeding catheters”. U.S. Pat. No. 6,019,746 for a “Low Profile Balloon Feeding Balloon” issued to Picha et al. on Feb. 1, 2000, provides an example of one balloon. 
     These catheters are frequently placed in a procedure called percutaneous endoscopic gastrostomy (frequently referred to as PEG). Traditionally, a PEG tube is placed using endoscopic guidance or x-ray guidance. In a conventional PEG procedure that places a PEG tube into a patient&#39;s stomach, an endoscope is used to observe that the patient&#39;s esophagus is unobstructed and to inspect and inflate the stomach to see that the area selected for the gastrostomy can be distended. If the location is suitable, this spot is selected. 
     A needle is inserted into the patient in the area in the appropriate location where a small incision may be made in the skin. An endoscopist will then typically watch through the endoscope as a needle pushes through the patient&#39;s skin, through the abdominal wall, and into the gastric lumen in the selected area to form a needle tract. A guide wire is passed through the needle into the gastric lumen (e.g. the stomach). The endoscopist will use an endoscopic snare to grasp the guide wire firmly. The snare, passed through the working channel of the endoscope, firmly grabs the guide wire. Both the endoscope and snare are then withdrawn together through the patient&#39;s mouth, pulling the guide wire with them. The end of the guide wire that extends out from the patient&#39;s mouth is subsequently attached to a retention element and the other end of the guide wire remains outside the patient&#39;s skin in the abdominal region. The retention element is guided into the patient&#39;s mouth (typically while the endoscope is completely removed from the patient) and pulled into the patient&#39;s gastric lumen as the guide wire is pulled from the end that remains outside the patient&#39;s skin. Once the retention element is in the gastric lumen, it is pulled snugly against the abdominal wall at the point of the stoma. 
     After suitable dilation of the stoma, a feeding tube may be inserted through the stoma while the stomach held snugly against the abdominal wall. The feeding tube has a retainer on the distal end that may be expanded within the stomach after the distal end of the feeding tube is inserted. One suitable feeding tube is described in U.S. patent application Ser. No. 13/245,542, filed Sep. 26, 2011, (publication US 2012/0078174A1) and commonly assigned. The &#39;542 feeding tube does not use an inflatable balloon as the retainer. Another suitable feeding tube is shown in U.S. Pat. No. 8,177,742 and uses an inflatable balloon as the retainer. 
     Sometimes during the insertion and unfurling or inflation of the feeding tube retainer, the retention element is in the way of the expandable retainer of the feeding tube and the retention element must be deflated or pushed out of the way in order to completely insert the distal end of the feeding tube. This can result in additional trauma to the patient and perhaps in the inability to insert this type of retainer successfully. 
     Accordingly, there is a need for improved retention elements that permit a user or health care provider to quickly and easily place feeding tubes through the patient&#39;s stoma and into a body lumen, such as, for example, a stomach lumen. Such a retention element should cooperate with a retainer and is designed to retain its position yet still allow the feeding tube to be inserted. The retention element should not get in the way of the expandable retainer of the feeding tube as the tube is inserted. 
     SUMMARY 
     In response to the difficulties and problems discussed herein, the present disclosure provides an innovative retention component for use with feeding tubes for placement in a gastric lumen, desirably under direct visualization using an endoscope. The retention component has a balloon desirably having an inflated shape with a recessed or concave center that provides space to accommodate the distal end of inserted feeding tubes. The retention component holds the stomach against the inner abdominal wall. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a drawing showing the retention component in cross-section on a guide wire in position within a stomach that has been pulled snugly against the inner abdominal wall. 
         FIG. 2  is a cross-sectional view of an inflated retention component and feeding tube showing the relationship of the two as the feeding tube is inserted. 
         FIG. 3A  is a cross-sectional view of an inflated retention component having a tie reinforcement. 
         FIG. 3B  is a view of the proximal end of the retention balloon shown in  FIG. 3A , showing the ties holding the balloon together. 
         FIG. 4  is a cross-sectional view of an inflated retention component having a skirt structure for reinforcement of the retention balloon. 
         FIG. 5  is a cross-sectional view of an inflated retention component having stiffer walls (indicated by darkened side lines) to provide reinforcement for the retention component. 
         FIG. 6  shows the retention component with a dilation balloon nesting within the concentric concavity of its proximal end. 
         FIGS. 7A and 7B  show a conventional enteral feeding tube having a balloon retainer in the un-inflated and inflated states, respectively. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to one or more embodiments, examples of which are illustrated in the drawings. It should be understood that features illustrated or described as part of one embodiment may be used with another embodiment to yield still a further embodiment. 
     Since the stomach is a common example of a gastric lumen, for the purpose of describing the present disclosure, the use of the term “stomach” is representative of all other gastric lumens or spaces (e.g. duodenum, jejunum, ileum, etc.), unless otherwise specified. 
     The function of the retention component  10  is to maintain the stomach (or other gastric lumens) against the abdominal wall during and after placement of an enteral feeding tube.  FIG. 1  shows the retention balloon  100  on the structural support  104  in place with the stomach wall  116  snugly against the inner abdominal wall  118 . 
     As shown in  FIG. 1 , the retention component  10  has an inflatable retention balloon  100  on a structural support  104 . The retention balloon  100  has at least one collar  102  on or near a distal  103  or proximal  105  end or between them, though desirably has two collars  102  as shown in  FIG. 2 . The balloon  100  desirably has an inflated conical shape that results in a concavity at the proximal end  105  of the balloon  100 . The concavity is desirably concentric. 
     The structural support  104  is elongated relative to the balloon  100  and may have an inflation lumen  107  in fluid communication with the balloon  100  so that the balloon  100  may be inflated and deflated as needed. The structural support  104  may be a cannula, stylet, rod or other support that may be used to move the balloon  100  as desired. The structural support  104  may be flexible or rigid or a combination of flexible and rigid sections as may be needed in a particular installation. 
     The feeding tube  200  is guided and advanced over the structural support  104  into the stoma ( FIG. 2 ). The inflated retention balloon  100  allows room for the retainer  202  of the feeding tube to enter the stomach. The retainer  202  can be deployed to hold the feeding tube in place as is conventionally known. The retention balloon  100  may then be deflated and removed from the patient.  FIG. 7A  shows a feeding tube  200  having an inflatable bumper or retainer  202  on the distal end. The feeding tube  200  is advanced over the structural support  104  while the retainer  202  is in its collapsed or insertion state, e.g. deflated for inflatable retainers, radially contracted for rigid retainers. Once the retainer  202  is in position in the stomach, the retainer  202  can be deployed, e.g. inflated ( FIG. 7B ) or radially extended. The deployed retainer  202  holds the stomach against the inner abdominal wall, and the retention balloon  100  may be removed. Installation of the feeding tube  200  is now complete and the feeding tube  200  may be placed in service. 
     As can be seen from the Figures, the generally conical retention balloon  100  when inflated has a cone apex  108 , a cone base  110 , and lateral surfaces or a wall  114  therebetween connecting the apex  108  and base  110 . As noted above, the balloon  100  is generally conical in shape, allowing for a recessed, concave center that provides space for the retainer  202  of the feeding tube  200 . It should be noted that although a conical embodiment is shown, a box-shaped or hemispherical shape would also function. The retention component holds the stomach against the inner abdominal wall while still allowing space in the recessed center to accommodate the distal end of subsequently inserted components. 
     It has been found that the inflated shape of the retention balloon  100  can sometimes result in the balloon base  110  and wall  114  folding backwards onto itself. “Folding backwards” means the part of the balloon that contacts the inner wall of the stomach, the base  110 , can fold towards the apex  108  of the balloon  100 . This can occur if an excessive amount of force is used to pull the retention balloon  100 , and hence the stomach, towards the inner abdominal wall. Should the retention balloon  100  fold backwards, the space for the feeding tube may be lost.  FIGS. 3 ,  4  and  5  provide possible solutions to this problem. 
       FIG. 3A  illustrates the use of a “ties”  122  that provide dimensional support upon inflation to the base  110  by connecting between points on the base  110  while allowing space for the retainer  202  of the feeding tube to pass into the concavity. These reinforcement ties, e.g. cords, mesh webbing, or an apertured disc, are flexible but not extensible.  FIG. 3B  is an end view drawing of the proximal end of the inflated balloon  100  and shows an embodiment of the ties  122  that do not cross the center of the balloon  100  but connect to the balloon  100  so that access to the center is not blocked, e.g. diagonally. 
       FIG. 4  shows an embodiment in which a second balloon  112  over the original retention balloon  100  acts as a skirt to provide conical shape retention for the balloon  100 . The second balloon  112  is a partially enveloping sleeve or skirt that to forces the balloon  100  to achieve an inflated conical shape. Another skirt embodiment is a non-inflating sleeve in place of balloon  112 ; this non-inflating sleeve can be a cylinder that deforms to have a larger end in the proximal direction upon inflation of retention balloon  100 , or the sleeve can be pre-shaped to have one end larger than the other with the larger end positioned proximally. 
       FIG. 5  shows yet another way of providing strength to the balloon  100  by making the side walls  114  of the balloon  100  between the apex  108  and the base  110  stiffer (indicated by darker lines). Stiffening the walls  114  may be accomplished through the use of a stiffer polymer than the balance of the balloon  100  or by making the walls thicker than the base and/or apex or both. 
     Use of non-compliant or semi-compliant materials and known shaping techniques (e.g. blow molding within pre-shaped cavities) can contribute to the conical shape of the balloon  100  between the collars  102 . Positioning of collars  102  on the structural support  104  further contributes to the conical shape.  FIG. 2  shows the collar  102  at the distal end  102  of the balloon  100  attached to the structural support  104  so there is no overlapping of the balloon  100  while the more proximally placed collar of the balloon  100  is attached to the structural support so that the balloon inverts over the collar. 
     The component  10  may include an inflatable dilation balloon  130  or be configured for positioning an inflatable dilation balloon  130  adjacent the retention balloon  100 , as shown in  FIG. 6 . When the component  10  includes a dilation balloon  130 , the dilation balloon  130  is supported on the structural support  104 . When the dilation balloon  130  is a separate component it is configured to be positioned over the structural support  104 . Whether included with the component  10  or provided separately, the dilation balloon  130  has two opposing ends where one (distal) end  132  is configured to at least partially nest within the concavity of the inflated retention balloon  100 . The dilation balloon  130  should have a uniform inflated diameter along a length between the distal and proximal ends  132 ,  134  and an opening in fluid communication with an inflation lumen  136 . 
     As described above, a needle is usually used to puncture the skin  120  above the abdomen and place a guide wire in the desired location. This is generally with the use of an endoscope inserted into the patient&#39;s stomach so that the initial puncture point can be observed from inside the stomach. 
     Outside-in Installation: 
     After insufflation of the stomach, the retention component  10  is percutaneously inserted into the stomach while the proximal end of the structural support  104  remains outside the body. The dilation balloon  130  is positioned so that the end  132  intended for nesting within the concavity of the retention balloon  100  is percutaneously inserted into the stomach and the other end  134  remains outside the body without completely covering the proximal end of the structural support  104 . The retention balloon  100  is inflated and a tractive (drawing) force is applied to the proximal end of the structural support  104  to draw the proximal end  105  of the inflated retention balloon  100  against the stomach. The dilation balloon  130  is inflated to enlarge the insertion tract to a defined stoma and then deflated. An enteral feeding tube  200  with its retainer  202  in the insertion state (i.e. furled, collapsed, or deflated) is inserted over the structural support  104 , over the deflated dilation balloon  130 , through the stoma and into the concavity of the inflated retention balloon  100 . The retainer  202  is deployed to a retention state (unfurled, extended, or inflated) within the concavity and the tube  200  is positioned so that the retainer  202  is against the stomach wall. The retention balloon  100  is deflated to release the tractive force. The structural support  104 , the retention component  10  and any other placement devices (e.g. dilation balloon  130 ) are removed through the tube  200 . 
     When the retention component  10  is used to place a feeding tube  200  with a non-inflatable retainer or bumper  202 , there is no need for gastropexy fasteners to aid in maintaining the stomach in apposition with the abdominal wall until these tissue structures fuse together. Feeding tubes  200  with such bumpers  202  have sufficient dimensional stability to maintain apposition of the stomach against the abdominal wall. When the retainer  202  is of the inflatable type, gastropexy is recommended to retain the stomach against the abdominal wall. 
     When the retention component  10  is used to place a feeding tube  200  with an inflatable retainer  202  or bumper, the retention balloon  100  may be left inflated around the inflated bumper  202  to maintain the stomach in apposition with the abdominal wall until these tissue structures fuse together sufficiently. After the apposition force provided by the retention component  10  is no longer needed, the retention balloon  100  may be deflated and the component  10  removed. 
     Inside-out Installation: 
     The retention component  10  may be placed from within the stomach through a percutaneous incision via the aid of a conventional guide wire. For such inside-out placement, a guide wire traversing through a percutaneous incision, the stomach, and the esophagus to outside of the mouth is attached to the proximal end of the structural support  104 . The endoscopic snare may be used to pull the guide wire. The guide wire is pulled back out through the incision and so pulls the retention component  10  into the stomach and through the incision until the retention component  10  is positioned as described above. The balance of the installation is the same as above. 
     Whether the “outside-in” or “inside-out” procedure is used, once the retention balloon  100  is successfully in place and inflated as shown in  FIG. 1  and the stoma is dilated, the feeding tube  200  may be placed. 
     In the practice of the disclosure the feeding tube  200  may have a tube size varying from about 4 to 6 French. The width of the base  110  of the inflated retention balloon  100  is larger than the size of the feeding tube retainer  202  (as shown in  FIG. 2 ) and may be between 26 and 28 French to allow for the deployment of the retainer  202  of the feeding tube component  10 . (Note, French is a measure of circumference based on the theory that non-round tubes of the same circumference will fit into the same incision. One French is approximately 0.33 mm or 0.013 inch). The balloon  100  may be made from any suitable polymer. Typical polymers include polyesters, polyurethanes, nylons, and polyolefins like polyethylene, polypropylene and polybutylene. 
     While the present disclosure has been described in connection with certain preferred embodiments it is to be understood that the subject matter encompassed by way of the present disclosure is not to be limited to those specific embodiments. On the contrary, it is intended for the subject matter of the disclosure to include all alternatives, modifications and equivalents as can be included within the spirit and scope of the following claims.