Abstract:
A catheter for inserting into a bodily structure. The catheter includes a primary lumen and a secondary lumen having a side hole for engaging under negative pressure with an inter-mural mucosa of the bodily structure. Methods of use of a catheter involving insertion of the catheter into a bodily structure and engaging the catheter under negative pressure with an inter-mural mucosa of the bodily structure.

Description:
REFERENCE TO RELATED APPLICATION 
     This application is a §371 National Stage of PCT International Application No. PCT/US2006/001136, filed Jan. 13, 2006, which claims benefit of U.S. Provisional Application No. 60/649,101, filed Feb. 3, 2005 the contents of all of which are hereby incorporated by reference into this application. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to endoscopic retrograde cholangiopancreatography and, more specifically, to methods and devices for selective endoscopic retrograde cholangiopancreatography. 
     2. Description of the Related Art 
     Endoscopic retrograde cholangiopancreatography (ERCP) is the visualization of the pancreatic and biliary ducts by means of endoscopic injection of a contrast medium through the hepatopancreatic ampulla (the ampulla of Vater). A retrograde image of both structures can be formed on an X-ray. ERCP may be used to facilitate the diagnosis of obstructions, for example, gallstones or cholangiocarcinoma. 
     In performing ERCP, an endoscope or catheter may be inserted through the mouth of the patient, down the esophagus, through the stomach, through the pylorus into the duodenum to the ampulla. A catheter or cannulatome may be inserted through the lumen of the endoscope or catheter to the ampulla to deliver radiocontrast into the bile ducts and/or pancreatic duct. The structures receiving radiocontrast may then be visualized by X-ray imaging techniques such as fluoroscopy. 
     Devices such as a catheter, guidewire, papillotome, etc. may be sent through the lumen of the endoscope or catheter for purposes such as radiocontrast delivery, specimen biopsy, etc. These devices may become obstructed by folds of the mucosa inside the ampullae that are either natural or an effect of the endoscope and/or its device&#39;s wrinkling of the mucosa as it is inserted into the ampullae. Similar folding may occur in the intra-mural portion of the CBD and/or pancreatic duct. 
       FIG. 1  is a diagram illustrating endoscopelcatheter redundant mucosa fold obstruction. As an endoscope or catheter  10  is inserted into the ampullae  11 , the CBD  13  and/or the pancreatic duct  14 , folds  12  within the inner-lining of the structures may form. These folds  12  may obstruct the endoscope or catheter  10  and/or a device such as a catheter, guidewire, papillotome, etc. that may be inserted through the endoscope or catheter  10 . 
     As these folds may complicate ERCP, it is desirable to use a method and device for straightening out folds within the ampullae, bile ducts and/or pancreatic duct when performing ERCP. 
     SUMMARY 
     A catheter for inserting into a bodily structure. The catheter includes a primary lumen for passing a device. One or more flaps or circumferential anchors protrude from a front tip of the catheter. The flaps or circumferential anchors engage with an inter-mural mucosa of the bodily structure. 
     A catheter for inserting into a bodily structure includes a primary lumen for passing a device and one or more secondary lumens with negative pressure for engaging with an inter-mural mucosa of the bodily structure. 
     A method for inserting a catheter into a bodily structure includes inserting a catheter with one or more flaps or circumferential anchors protruding from a front tip of the catheter into the bodily structure. The catheter is pulled back to engage the one or more flaps or circumferential anchors with an inter-mural mucosa of the bodily structure. The inter-mural mucosa is thereby pulled taut. A device is inserted through a primary lumen of the catheter into the bodily structure. 
     A method for inserting a catheter into a bodily structure includes inserting a catheter into the bodily structure. One or more points of negative pressure on the catheter are activated to engage an inter-mural mucosa of the bodily structure. The catheter is pulled back to pull the inter-mural mucosa taut. A device is inserted through a primary lumen of the catheter into the bodily structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete appreciation of the present disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
         FIG. 1  is a diagram illustrating endoscope/catheter redundant mucosa fold obstruction; 
         FIG. 2  is a diagram showing a specialized ERCP catheter according to an embodiment of the present invention; 
         FIG. 3  is a diagram showing a specialized ERCP catheter with complete flaps according to an embodiment of the present invention; 
         FIGS. 4A ,  4 B, and  4 C show a method for using a specialized catheter to straighten out wrinkles within the inter-mural mucosa of the ampullae, bile ducts and/or pancreatic duct according to an embodiment of the present invention; 
         FIGS. 5A and 5B  show a specialized catheter according to such an embodiment of the present invention; 
         FIG. 6  shows a double-walled catheter that may be used according to an embodiment of the present invention; 
         FIG. 7  shows a double-lumen catheter that may be used according to an embodiment of the present invention; 
         FIGS. 8A-8D  show a catheter with a retractable flap according to embodiments of the present invention; and 
         FIGS. 9A and 9B  show retractable flaps according to another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     In describing the preferred embodiments of the present disclosure illustrated in the drawings, specific terminology is employed for sake of clarity. However, the present disclosure is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents which operate in a similar manner. 
     Embodiments of the present invention seek to straighten out folds within the inner walls of bodily structures, for example, the ampullae, bile ducts and/or pancreatic duct, for example, when performing ERCP. As mentioned above, the folds may be preexisting or may be caused by the insertion of a catheter into the structure. For example, as the catheter is inserted into the structure, the inner walls of the structure may be pushed upwards causing a buckling resulting in the folding of the inner walls of the structure. 
     Embodiments of the present invention may straighten the folds by pulling the inner surface of the structure, for example, the inter-mural mucosa of the ampullae, bile ducts and/or pancreatic duct, tout and smooth. Insertion if a device such as a catheter, guidewire, papillotome may then be facilitated by the removal of potentially obstructive wrinkles. For example, ERCP may be performed. 
     A specialized ERCP catheter may be used to straighten out wrinkles within the inter-mural mucosa of the ampullae, bile ducts and/or pancreatic duct.  FIG. 2  is a diagram showing a specialized ERCP catheter according to an embodiment of the present invention. The specialized ERCP catheter  21  may have a tip opening  22  for protrusion of a device such as a catheter, guidewire, papillotome, or contrast injection. The front tip of the catheter  21  may have one or more rows of flaps or petals  23  (referred to herein as flaps) around the perimeter of the catheter. There may be a number of rows of flaps  23 . For example, there may be 1, 2, or three rows of flaps  23 . Each row of flaps  23  may have a number of flaps  23 , for example, each row may have 1, 2, 3 or 4 flaps  23 . The flaps  23  may have a flat and/or blunt ends for engaging the redundant mucosa, for example, within the ampullae. The catheter  21  may then be gently pulled back. As the catheter  21  is pulled back, the flaps  23  engage with the redundant mucosa and may pull the inner surface of the ampullae tout and smooth thereby minimizing the number and size of wrinkles within the intramural mucosa that may potentially obstruct the catheter and/or the protruding device. 
     According to one embodiment of the present invention, the flaps may be incomplete, meaning that the flaps are shaped to push into the thickness of the inter-mural mucosa without cutting into the internal lumen of the bodily structure, for example, the ampullae. According to another embodiment of the present invention, the flaps may be complete, meaning that the flaps are shaped to cut into the internal lumen of the bodily structure. 
     Embodiments of the present invention may use circumferential anchors rather than or in addition to flaps.  FIG. 3  is a diagram showing a specialized ERCP catheter with circumferential anchors according to an embodiment of the present invention. The catheter  31  may have a top opening  32  for protrusion of a device such as a catheter, guidewire, papillotome, or contrast injection. The front tip of the catheter  31  may have one or more circumferential anchors  33  around the perimeter of the catheter  31 . The circumferential anchors  33  may extend 360 degrees around the entire circumpherence of the catheter  31 . For example, there may be 1, 2 or 3 circumferential anchors  33 . The circumferential anchors  33  may either be fully enclosed raised cone or may be thin and without volume. The circumferential anchors  33  may have a flat and/or blunt ends for engaging the redundant mucosa, for example, within the ampullae. The catheter  31  may then be gently pulled back. As the catheter  31  is pulled back, the circumferential anchors  33  engage with the redundant mucosa and may pull the inner surface of the ampullae tout and smooth thereby minimizing the number and size of the wrinkles. 
       FIGS. 4A ,  4 B, and  4 C show a method for using a specialized catheter to straighten out wrinkles within the inter-mural mucosa of the ampullae, bile ducts and/or pancreatic duct according to an embodiment of the present invention. Referring to  FIG. 4A , the specialized catheter  40  may be inserted into, for example, the ampullae  11 , the CBD  13  and/or the pancreatic duct  14 . As the catheter  40  is inserted, folds  12  may appear in the inter-mural surface of the structure. 
       FIG. 4B  shows the catheter  40  inserted into the ampullae  11 . For example, the tip of the catheter  40  may be inserted 2-5 mm into the ampullary orifice. Once the catheter  40  has been inserted, the catheter may be gently pulled back. The blunt ends of the catheter&#39;s flaps and/or circumferential anchors may engage the redundant mucosa inside the ampullae. The flaps and/or circumferential anchors may then function as gentle hooks or anchors around the perimeter of the tip of the catheter to taut and straighten the redundant mucosa more distal to the flaps and/or circumferential anchors. 
     The pulling motion may minimize the number and size of the folds and may thereby minimize obstruction as seen in  FIG. 4C . By straightening the ampullae, folding may also be reduced in the CBD and/or the pancreatic duct. After the structures have been straightened, a guidewire may be advanced through the catheter and/or a contrast may be injected. Thus, the wire&#39;s tip could straighten the lumen of the structure and more easily travel through the structure without getting stuck on a wrinkle. 
     The number and position of the flaps and/or circumferential anchors around the catheter&#39;s tip&#39;s perimeter may be varied to achieve the desired degree to which the lumen of the structure is opened. For example, a flap placed at the 11 o&#39;clock orientation may make a biliary cannulation more plausible while a flap placed at the 3 o&#39;clock orientation make a pancreatic cannulation more plausible. 
     The catheter its self may be single-, two-, or three-channeled for simultaneous use with wires and contrast. The flaps and/or circumferential anchors of the present invention may also be applied in the papillotomes. 
     Other embodiments of the present invention may minimize mucosal folds by engaging the rim of the ampullae and pulling it out and open while a thinner catheter and/or guidewire is passed through the taut internal canal.  FIGS. 5A and 5B  show a specialized catheter according to such an embodiment of the present invention.  FIG. 5A  shows the specialized catheter  50  approaching the ampullae  54 . The catheter  50  may contain one or more suction channels  51  and  52 . For example, there may be two suction channels  51  and  52  positioned at 9 and 3 o&#39;clock, or at 11 o&#39;clock for selective bile duct cannulation. The suction channels  51  and  52  may deliver negative pressure suction  55  to create points of negative pressure at the tips of the suction channels  51  and  52 . As the catheter  50  approaches the ampullae  54 , the rim of the ampullae  54  may be pulled into the suction channels  51  and  52  by the negative pressure suction  55 , as seen in  FIG. 5B . This pulling of the rim of the ampullae  54  may pull the redundant mucosa tout thereby minimizing wrinkles. A device, for example a catheter, guidewire, papillotome, or contrast injection may then be sent through the inner lumen  53  of the catheter  50 , for example, to perform ERCP. Afterwards, the suction  55  may be discontinues to release the ampullae  54  to facilitate removal of the catheter  50 . To minimize the risk of undesired engagement of the mucosa, the suction may be inactive during caterer  50  insertion. 
     According to another embodiment of the present invention, a double-walled catheter may be used. An example of such an embodiment is shown in  FIG. 6 . Here, a double-walled catheter  60  includes an outer passageway  62  and an inner passageway  63  separated by an inner catheter  61 . Negative pressure suction  65  may be applied to the outer passageway  62  to create a point of negative pressure at the tip of the outer passageway  62  so that as the catheter  60  approaches the ampullae  64 , the entire perimeter of the ampullae  64  may be pulled into the outer passageway  62  by the negative pressure suction  65 . This pulling of the perimeter of the ampullae  64  may pull the redundant mucosa tout thereby minimizing obscuring wrinkles. A device, for example a catheter, guidewire, papillotome, or contrast injection may then be sent through the inner passageway  63  of the catheter  60 , for example, to perform ERCP. Afterwards, the suction  65  may be discontinues to release the ampullae  64  to facilitate removal of the catheter  60 . To minimize the risk of undesired engagement of the mucosa, the suction may be inactive during caterer  60  insertion. 
     According to another embodiment of the present invention, a double-lumen catheter may be used. An example of such an embodiment is shown in  FIG. 7 . Here, a double-lumen catheter  71  includes a primary lumen  72  and a secondary lumen  73 . Negative pressure suction  75  may be applied to the secondary lumen  73 . The secondary lumen may have a single side hole  74  for attaching to the lining inside the orifice at a single point by the force of the suction  75 . This single side hole  74  acting as a point of negative pressure. Once the side hole  74  has attached to the lining, the catheter  71  may be pulled back to straighten the redundant mucosa and minimize obstructive wrinkles. A device, for example a catheter, guidewire, papillotome, or contrast injection may then be sent through the primary lumen  72  of the catheter  71  through a front opening  76 , for example, to perform ERCP. Afterwards, the suction  75  may be discontinues to release the orifice inner lining to facilitate removal of the catheter  71 . To minimize the risk of undesired engagement of the mucosa, the suction may be inactive during caterer  71  insertion. 
     In embodiments of the present invention that use flaps and/or circumferential anchors, the flat and/or blunt ends of the flaps and/or circumferential anchors may prevent perforation of the mucosa. Additionally, at sufficient tension, for example, when the catheter is removed, the flaps and/or circumferential anchors should be able to buckle over releasing the mucosa. Removal of the catheter should not cause significant trauma to the mucosa. 
     Other embodiments of the present invention may facilitate removal of the catheter by utilizing retractable flaps and/or circumferential anchors.  FIGS. 8A-8D  show examples of catheters with retractable flaps according to embodiments of the present invention.  FIG. 8A  shows a catheter  80  with a retractable flap  81  in the retracted position. The flap  81  may be retracted for insertion and/or removal of the catheter.  FIG. 8B  shows a catheter  80  with a retractable flap  81  in the open position. The flap  81  may be open when engaging the redundant mucosa. 
     The retractable flap  81  may be biased in either the open position or the closed position. If the flap  81  is biased in the open position, the flap  81  may be pulled closed by a wire  82  that runs the length of the catheter  80  and exits the catheter  80  through a point  83  located behind the flap  81  as shown in  FIG. 8C . If the flap  81  is biased in the closed position, the flap  81  may be pulled open by a wire  82  that runs the length of the catheter  80  and exits the catheter  80  through a point  84  above the flap  81  as shown in  FIG. 8D . It is to be understood that the catheter  80  may have any number of flap  81  as described above. 
       FIGS. 9A and 9B  show retractable flaps according to another embodiment of the present invention. The catheter  90  may have a side hole  92 . A retractable flap  91  may then be pushed and retracted though the side hole  92  as desired. The retractable flap  91  may be made of a memory-shaped flat wire.  FIG. 9A  shows such the catheter  90  with a partially extended flap  91  while  FIG. 9B  shows the catheter  90  with a fully extended flap  91 . It is to be understood that the catheter  90  may have any number of flaps  91  as described above. 
     Embodiments of the present invention may utilize circumferential anchors such as those shown in  FIG. 3  that are retractable. Such circumferential anchors may open and close, for example, in an umbrella like fashion. 
     The above specific embodiments are illustrative, and many variations can be introduced on these embodiments without departing from the spirit of the disclosure or from the scope of the appended claims. For example, elements and/or features of different illustrative embodiments may be combined with each other and/or substituted for each other within the scope of this disclosure and appended claims.