Abstract:
A device for directing a wire guide into a bodily passageway such as a branch of the biliary tree or other difficult to access bodily passageway. The device includes a member, such as an inflatable balloon or a self-expanding basket, for obstructing a first passage. Once the balloon is inflated, or the basket expanded, the wire guide can be reliably directed or deflected into a preferred adjacent passageway in order to cannulate the preferred adjacent passageway. A procedure for cannulating a preferred passageway by obstructing a passageway in the natural flow-path of a wire guide is also provided.

Description:
RELATED APPLICATIONS 
     This claims the benefit of U.S. Provisional Application Ser. No. 60/384,055, filed May 29, 2002, entitled “Device For Directing A Wire Guide.” 
    
    
     TECHNICAL FIELDS 
     This invention relates to medical devices, and more particularly to a flexible elongate member having means to direct a wire guide through a bodily passageway. 
     BACKGROUND OF THE INVENTION 
     Navigating a wire guide or catheter through a body passage can be especially problematic when attempting to negotiate a branching pathway, such as a bifurcated duct or vessel. Although adding steerability to a medical device is possible, it usually adds to the diameter of the device (a serious disadvantage in endoscopy) and may not result in a device having the desired characteristics. Most wire guides lack a satisfactory means to guide them in a particular direction, especially a direction that is against the natural pathway that the device wants to take. An example of an area of the body where this poses a problem is the biliary tree, where wire guides are often introduced prior to ERCP and other procedures involving the gall bladder, pancreas, liver, and associated ducts. The biliary tree includes bifurcations at the junction of the biliary and pancreatic ducts, as well as the right and left hepatic ducts. Using fluoroscopy or a cholangioscope, it is sometimes possible to successfully navigate the wire guide or device into the desired branch of the bifurcation; however, some anatomies can make that extremely difficult. 
     Adding steerability to a small-diameter wire guide like those used in endoscopy is generally not an option. One solution is to occlude the non-target branch of the bifurcation by inflating a balloon just past the junction. The balloon can be used to deflect a wire guide which is separately introduced through a different lumen of the scope, thereby directing it into the desired duct. While this method has been used successfully, a certain amount of trial and error is often required, primarily due to difficulties in visualizing the ducts and the lack of directional control over the wire guide. What is needed is a device that is configured such that the wire guide can be aligned with the occlusive means such that it reliably deflects it in a predictable manner and direction to successfully cannulate a particular branch of a bifurcated duct or vessel. 
     SUMMARY OF THE INVENTION 
     The foregoing problems are solved and a technical advance is achieved in an illustrative apparatus comprising an elongate member, such as a endoscopic balloon catheter, that includes an obstructive member (e.g., an inflatable or expandable member) having a first configuration and a second expanded configuration sized and configured for blocking a first bodily passageway, such as one branch of a bifurcated duct, blood vessel, or the bronchial tree. The apparatus further includes a first lumen having an external opening that is situated and aligned such that an elongated medical device, such as a wire guide, is advanced out of the external opening, whereby it contacts the obstructive member in the expanded configuration and is deflected away from the first bodily passageway and into the second bodily passageway (e.g., the opposite branch of the bifurcation) in a generally predictable manner. 
     In a first aspect of the present invention, the elongate member comprises a balloon catheter in which the obstructive member comprises a balloon that is inflated to block one branch of a bifurcated passageway. A wire guide is advanced through a first lumen of the balloon catheter until it exits via an external opening, such as a scive formed in the tubing proximal to the balloon. The external opening is aligned and configured such that the wire guide deflects out of the lumen where it contacts the inflated balloon and is further deflected away from the blocked first bodily passageway of the bifurcation (the natural or “preferred” pathway that the wire guide would otherwise travel) and into the open, second bodily passageway of the bifurcation. In the illustrative embodiment, a plug situated within the first lumen beyond the scive, forces deflection of the wire guide out of the lumen and external opening. The balloon catheter includes a second lumen for accommodating a wire guide that is extendable from the distal tip of the catheter to access the first bodily passageway, and a third lumen for inflation of the balloon. 
     In a second aspect of the invention, the apparatus includes an outer sheath with at least two lumens, the first lumen coaxially housing an elongate member, such as a balloon catheter, and a second lumen for a wire guide. The balloon catheter is advanced from the distal end of the outer member and inflated to block the first bodily passageway. The wire guide is advanced from the external opening located at the distal end of the outer sheath, the opening being situated such that the advancing wire guide deflects off of the surface of the expanded balloon and toward the second bodily passageway. 
     In a third aspect of the invention, the obstructive member of the apparatus comprises a self-expanding member, such as a stainless steel or nitinol basket that includes a surface configuration of sufficient density, such as fabric or metallic mesh, that allows a wire guide to deflect off of the obstructive member. Alternatively, the obstructive member may be made expandable in another manner, such as longitudinal compression or some other well-known means. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which: 
         FIG. 1  depicts a side view of the illustrative embodiment of the present invention; 
         FIG. 2  depicts a partially sectioned detail view of the embodiment of  FIG. 1 ; 
         FIG. 3  depicts a cross-sectional view taken along line  3 — 3  of  FIG. 1 ; 
         FIG. 4  depicts the embodiment of  FIG. 1  in situ; 
         FIG. 5  depicts a pictorial view of an alternative embodiment of the present invention that includes an outer member; and 
         FIG. 6  depicts an alternative embodiment of the present invention in situ, wherein the obstructive member comprises an expandable member. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  depicts an illustrative embodiment of the present invention. In particular, an apparatus  10  is provided for directing an elongate medical device  14 , such as a wire guide or catheter, into a particular bodily passageway, such as a branch of a bifurcated duct, common duct, or vessel  31  (which is depicted in  FIGS. 4 and 6 ). The apparatus comprises an elongate member  11 , such as a catheter, that includes an obstructive member  12  affixed about the distal portion  46  thereof. The obstructive member  12  is remotely expandable or inflatable from a first configuration  44  (e.g.,  FIG. 5 ) and size, such as one having a low profile that enables the elongate member to be navigated within the patient, to a second, larger configuration  45  (e.g.,  FIG. 4 ) and size for at least partially occluding a particular bodily passageway into which the operator does not wish the elongate medical device  14  to enter. The portion of the apparatus  10  illustrated in  FIG. 2  includes a first lumen  16  sized to accommodate the elongate medical device  14  which is then advanced out of an external opening  19 , such as a scive  20  in the apparatus that communicates with the first lumen  16 . The external opening  19  is situated or aligned relative to the obstructive member  12  such that as the elongate medical device  14  is advanced out of the external opening  19 , it comes into contact with the expanded obstructive member  12  (i.e., when in the second configuration  45 ) and is deflected in a particular direction. For example, the medical device  14  is deflected from its natural pathway and away from the first bodily passageway  33  (see  FIG. 4 ), and toward the intended second bodily passageway  34 , which typically is the opposite branch emanating from the common duct or vessel  31  through which the apparatus is being navigated. 
     A first embodiment of the present invention is depicted in  FIGS. 1–4  for use in the biliary tree in which the elongate member  11  of the apparatus  10  comprises a endoscopic balloon catheter and the obstructive member  12  comprises a balloon, typically made of a compliant material such as latex or silicone. The shaft portion of the elongate member  11 , which is made of a biocompatible polymer, such as PEBAX® resin (ATOFINA Chemicals, Inc., Philadelphia, Pa.) or some other suitable material, includes three passageways or lumens  16 ,  17 ,  18  extending therethrough ( FIG. 3 ). The first lumen  16  is sized to accommodate a standard wire guide  14 , such as a 0.025″ METRO™ Wire Guide (Wilson-Cook Medical). In the illustrative embodiment, the second lumen  17  is sized to accept a second wire guide  15 , such as a 0.035″ METRO™ Wire Guide. The second lumen  17  extends the length of the catheter  11 . At the distal end of lumen  17 , catheter  11  includes a distal opening  41  from which the second wire guide  15  may exit to access the blocked passageway or provide access so that the apparatus  10  can track over the second wire guide  15  if already in place. The third lumen  18  has a diameter of approximately 0.019″ and communicates with an inflation port  38  located inside the balloon  13 . The three lumens  16 ,  17 ,  18  each are accessible via hub connectors  27 ,  28 ,  29 , respectively, which comprise the proximal hub assembly  25 . The illustrative hub connector  27  that feeds the inflation lumen  18  and balloon  13 , includes a stopcock and a luer fitting for attaching to an inflation device  26 , such as a syringe. The hub connectors  28 ,  29  for the first  14  and second  15  wire guides, respectively, each include a Touhy-Borst adaptor and side-arm port  47  for infusion of fluids around the wire guide  14 ,  15 , if necessary. 
     Referring now to  FIG. 2 , the catheter lumen  16  for accommodating the wire guide  14  of the illustrative first embodiment includes an external opening  19  that comprises a scive  20  formed in the side of the tubing at a location proximal to the balloon  13 . A plug  21 , such as a metal or plastic insert or other permanent obstruction such as a cured adhesive material, helps to deflect and force the advancing wire guide out of lumen  16  via the scive  20 , which is configured to guide the wire guide  14  toward the balloon  13 . In the embodiment shown, the proximal edge of the balloon  13  is located about 1–2 cm from the external opening  19 . The balloon  13  is affixed to the shaft of the catheter using a standard bond means  68 , such as an adhesive and a wrapping. Additionally, radiopaque metal bands  22 ,  23  are placed to identify the proximal and distal ends of the balloon. Another radiopaque maker  26 , such as a band of radiopaque ink, is also conveniently included proximal to the external opening  19 . The typical diameter of the illustrative balloon  13  intended for biliary use, is approximately 10–15 mm when fully inflated. The point of contact  24  at which the tip of the wire guide  14  first abuts the balloon  13 , when the balloon is in the inflated configuration  45 , is somewhat variable, depending on the shape and size of the balloon when lodged within the first passageway; however, it is generally located as a point along the balloon&#39;s proximal or rearward portion such that when the balloon  13  is properly inflated (i.e., not overinflated or underinflated), the advancing wire guide  14  glances off of the balloon and is directed laterally (i.e., further away from the longitudinal axis of the catheter  11 ). It should be noted that an overinflated balloon may assume a squarish shape that may not permit the wire guide  14  to properly deflect in the desired manner. 
       FIG. 4  depicts the illustrative endoscopic biliary catheter being used to direct a wire guide away from the obstructed first bodily passageway  33 , such as the right hepatic duct, and into a second bodily passageway  34 , such as the left hepatic duct. In this particular instance, the physician may have attempted to cannulate the left (second) branch  34 , but was unable to do so because the wire guide  14  tended to follow a natural pathway into the right (first) branch  33  instead. To address this problem, the apparatus  10  is advanced just pass the point of bifurcation  32  into the first branch  33 , which in the illustrative situation, has been cannulated by the second wire guide  15 . The balloon  13  is then inflated such that it generally obstructs the entrance to the first or right branch  33 . The wire guide  14  is then manually advanced through the catheter  11  and out of the scive  20 , where it contacts the balloon  13  along the rearward portion  24  thereof, thereby deflecting the wire guide  14  away from the balloon  13  and toward, and ultimately into, the second or left branch  34 . Once successful cannulation has occurred, balloon  13  can be deflated and the catheter portion  11  of the apparatus withdrawn, leaving the wire guide  14  (or both wire guides  14 ,  15 ) in place. 
     A second embodiment of the present invention is depicted in  FIG. 5  in which the apparatus  10  further includes an outer member  35  having a first passageway  48  for receiving the first wire guide  14  and a second passageway  49  for accommodating the elongate member  11 , which in the illustrative embodiment, comprises a balloon catheter. The external opening  19 , through which the wire guide  14  exits to contact and deflect off of the balloon  13  (shown here in the first or deflated configuration  44 ), is located at the distal end  40  of outer member  35 , rather than at an intermediate point along the elongate member  11  as in the embodiment of  FIG. 1 . The second passageway  49  for the balloon catheter  11  and the first passageway  48  for the wire guide  14  are aligned with one another such that the wire guide  14  contacts the balloon  13  at a location  24  that enables the wire guide to be redirected in a manner similar to that depicted for the embodiment of  FIG. 1 . In the illustrative embodiment of  FIG. 5 , the elongate member includes lumens for inflating the balloon  13  and accommodating a second wire guide  15 , but lacks the third lumen for receiving the first wire guide  14 , which instead, is housed within the outer member  35 . 
     A third embodiment of the present invention is depicted in  FIG. 6 , in which the obstructive member  12  comprises an expandable member such as expandable basket  93 . In this embodiment, a self-expanding wire basket is mounted on an elongate member  11  comprising a flexible braided sheath, nitinol shaft, or the like to which an expandable basket  93  may be affixed. The wire members  50  of the expandable basket  93  are typically made of spring stainless steel or nitinol, such that they resiliently assume the expanded configuration  45  upon being advanced from the constraining outer member  35 . The expandable basket  93  preferably includes a mesh covering  37 , preferably made of a tight-woven and durable material, such as nylon, polyethylene terepthalate, etc. such that the wire guide  14  will deflect off of, rather than penetrate the fabric. It is possible, however, to construct a basket with a sufficient density of wire members  50  to accomplish the same function. In a related embodiment, the wire members  50  of the expandable member  93  could be eliminated and the mesh covering  37  comprise a material with shape memory, such as fine nitinol wire, so that it assumes the expanded configuration  45  with sufficient rigidity to form an effective obstructive member  12  for deflecting the wire guide  14 . The illustrative embodiment optionally includes a lumen  17  for receiving a second wire guide  15 . It should be noted that it is also within the scope of the invention for the expandable member  93  to be manually expandable, such as a basket that must be axially manipulated (i.e., longitudinally compressed) in order to expand the device, rather than the device being resiliently self-expanding. 
     Any other undisclosed or incidental details of the construction or composition of the various elements of the disclosed embodiment of the present invention are not believed to be critical to the achievement of the advantages of the present invention, so long as the elements possess the attributes needed for them to perform as disclosed. Certainly, one skilled in the medical arts would be able to conceive of a wide variety of obstructive member and elongate member configurations and successful combinations thereof. The selection of these and other details of construction are believed to be well within the ability of one of even rudimental skills in this area, in view of the present disclosure. Illustrative embodiments of the present invention have been described in considerable detail for the purpose of disclosing a practical, operative structure whereby the invention may be practiced advantageously. The designs described herein are intended to be exemplary only. The novel characteristics of the invention may be incorporated in other structural forms without departing from the spirit and scope of the invention. The invention encompasses embodiments both comprising and consisting of the elements described with reference to the illustrative embodiments. Unless otherwise indicated, all ordinary words and terms used herein shall take their customary meaning as defined in  The New Shorter Oxford English Dictionary , 1993 edition. All technical terms shall take on their customary meaning as established by the appropriate technical discipline utilized by those normally skilled in that particular art area. All medical terms shall take their meaning as defined by  Stedman&#39;s Medical Dictionary , 27th edition.