Catheter unit for cholangiography

Abstract

A catheter unit for use in operative cholangiography comprising a transparent elongated conduit member having a rounded, open distal end for insertion into the biliary tree and an open proximal end, and a transparent adapter in leak-proof engagement with the conduit member adjacent its proximal end. The adapter includes a recess communicating with the proximal end whereby a source of fluid may be placed in the recess for the transmittal of fluid to the conduit member. The conduit member includes a smoothly rounded enlargement set back from the distal end a distance of between about 3/16 inch and about one inch whereby, when the enlargement is located in the cystic duct of a patient, the distal end will be located in the common duct.

Description

BACKGROUND OF THE INVENTION

This invention relates to a medical device for use in operative cholangiography.

Operative cholangiography is the x-ray visualization of the biliary system of a patient during an operation (typically, removal of the gallbladder). During a gallbladder removal procedure (i.e., cholecystectomy) the surgeon typically attempts to determine the presence of stones in the duct system exclusive of the gallbladder itself. Stones in the common bile duct (i.e., the duct formed by the confluence of the cystic duct and the hepatic duct), however, are typically difficult to detect by mere palpation. On the other hand, surgical intervention into the common duct may itself be a frequent source of post-cholecystectomy morbidity, just as overlooked stones may be, and thus is not routinely recommended absent an indication of the presence of stones. Cholangiography is of assistance in this circumstance and involves the injection of a radio-opaque dye into the biliary system and the subsequent x-ray visualization of the biliary ducts to determine the presence of stones or other blockages.

Despite the evident value of cholangiography, its use as a routine matter has been greatly restricted because of the difficulty in manipulating, and otherwise properly employing, the implements previously proposed for supplying the dye to the biliary system. These prior art devices have included rigid needles incorporating a bulge which cooperates with a modified hemostat to retain the needle within the cystic duct; flexible catheters having regions of increased friction near the distal end to serve as a locus for a ligature tied around the cystic duct; flexible catheters having an exterior formation immediately adjacent the distal end providing a shoulder which cooperates with a ligature tied to the cystic duct to inhibit unwanted withdrawal of the catheter from the duct; etc.

Each of the prior devices, including those just mentioned, suffers from one or more of various drawbacks which have contributed to the dissatisfaction of many surgeons with operative cholangiography as a routine procedure during a cholecystectomy. These problems include implement designs which can cause damage to internal tissue in the biliary system; difficulty, or even inability, to properly locate the distal end of the dye delivering implement to obtain maximum distribution of the dye in the common duct; the difficulty in manually locating, after the implement has entered the cystic duct, the exact location of a ligature receiving formation on the implement; the use of expensive materials which render the implement non-disposable; the provision of implements which are not adequately visually and radio-transparent; and the provision of implements in which the diameter of the conduit for the dye changes intermediate the distal and proximal ends of the implement. It is to be understood that various of these defects of prior implements have been discovered according to the present invention rather than being evident problems requiring solution. Typically, only broadly stated defects have heretofore been recognized (e.g., the implement would prematurely slip out of the cystic duct or the x-ray results were misleading or ambiguous).

In view of the foregoing, it is a principle object of the present invention to provide an improved implement for use in operative cholangiography which facilitates the insertion, orientation, and retention of the implement in the appropriate body cavity. More specifically, it is an object to provide an implement which overcomes the various specific problems, listed above, which have been identified according to the present invention.

SUMMARY OF THE INVENTION

To achieve these and other objects, as shall further appear, there is provided according to the invention a catheter unit for use in operative cholangiography which comprises a transparent elongated conduit member having a founded open distal end for insertion into a body cavity and an open proximal end. The unit also comprises a transparent adapter in leak-proof engagement with the conduit member adjacent that member's proximal end. The adapter includes a recess communicating with the conduit member proximal end, whereby a source of fluid may be placed in that recess for the transmittal of fluid to the conduit member. The conduit member includes a smoothly rounded enlargement set back from its distal end a distance of between about 3/16 inch and about 1 inch, whereby, when the enlargement is located in the cystic duct of a patient, the distal end will be located in the common duct of the patient. Preferably, the enlargement comprises an integral bead around the exterior of the conduit member; the enlargement is located approximately 3/8 inch from the distal end; the conduit member includes a substantially rigid tip portion extending from the distal end to at least a location of the enlargement and the remainder of the conduit member is flexible; and the adapter is bonded to the exterior surface of the conduit member thereby avoiding a reduction in the diameter of the conduit through which the fluid passes.

BRIEF DESCRIPTION OF THE DRAWING

Other objects, features, and advantages of the invention will appear from the following description of a particular preferred embodiment, taken together with the accompanying drawing. In the drawing:

FIG. 1 is a partly broken away perspective view of a catheter unit for use in operative cholangiography constructed according to the present invention;

FIG. 2 is an enlarged sectional view of a portion of the catheter unit of FIG. 1 adjacent the distal end thereof; and

FIG. 3 is a partly broken away side elevation of the distal portion of an alternative embodiment.

DETAILED DESCRIPTION OF A PARTICULAR PREFERRED EMBODIMENT

Referring to the drawing, the catheter unit 10 comprises a transparent conduit member 12 and a transparent adapter 14. The adapter 14 is bonded to the proximal end 16 of the conduit member around the exterior thereof. A recess 18 within the adapter 14 communicates with the distal end 16 of the conduit member and is sized and shaped to receive a standard syringe luer. The conduit member 12 is generally flexible but may include a portion 20 of less flexibility adjacent the distal end 22. (Alternatively a separate rigid molded tip member 23 (FIG. 3) may be secured to the flexible conduit member.) A smoothly rounded enlargement 24 is provided on the member 12. The enlargement is preferably in the form of a molded or bonded bead of substantially the diameter of a cystic duct and formed from the same plastic material (of any conventional type) which forms the body of the conduit member 12. The enlargement 24 is set back from the distal end 22 a distance of between about 3/16 inch and about 1 inch, preferably about 3/8 inch. The conduit member 12 has a smoothly rounded profile, as at 26, immediately adjacent the distal end 22.

In operation, after the surgeon has exposed the gall-bladder and cystic duct, an incision is made in the cystic duct and the distal end of the conduit member is inserted through the incision and the conduit member pushed into the duct until the enlargement 24 can be felt to be lodged in the cystic duct adjacent its intersection with the common duct. When in that location, owing to the set back of the enlargement from the distal end 22, the distal end will be positively positioned within the common duct for ultimate distribution of dye to the common duct. A ligature is then tied around the cystic duct behind the enlargement which serves the additional purpose of cooperating with the ligature to retain the conduit member in place. In embodiments which include the more rigid tip portion of the catheter, this feature facilitates the working of the catheter past the spiral valves present in the cystic duct and the prevention of conduit collapse due to the ligature. Also the presence of the bead prevents the retrograde of the dye.

Since the conduit member 12 and the adapter 14 are conventionally filled with saline solution prior to insertion into the biliary system, the transparency of those elements provides for a convenient and positive determination of the presence or absence of air bubbles within the solution. Such air bubbles, if injected into the common duct, can be interpreted to be stones in the ultimate cholangiogram and are thus most undesirable. After the ligature has been tied the luer of a syringe containing the dye is inserted into the recess of the adapter and the dye is forced into and through the conduit member 12. The dye thus enters the common duct of the patient and an x-ray may then be taken. Withdrawal of the conduit member from the duct system and removal of the gallbladder can proceed in a conventional fashion.

Owing to the bonding of the adapter 14 to the exterior of the conduit member 12 rather than providing an adapter or needle for insertion into the conduit member, a constant cross section of the conduit through which the dye will flow is assured and, thus, there will be no pressure changes as the dye passes through the adapter and conduit member. Such pressure changes, which will occur with certain prior art constructions, can be misinterpreted by the surgeon as indicating a resistance to the flow of dye after it has passed from the distal end 22 of the conduit member, and, thus, an indication of the presence of stones or other blockages in the biliary system. Additionally, inadvertent leakage of the junction is prevented as might be found in separable attachments.

While a particular preferred embodiment has been illustrated in the drawing and described in detail herein, other embodiments, of course, are within the scope of the invention and the following claims.

Claims

I claim:

1. A catheter unit for use in operative cholangiography comprising a transparent elongated conduit member having a rounded, open distal end for insertion into a body cavity and an open proximal end, and a transparent adapter in leak-proof engagement with said conduit member adjacent said proximal end, said adapter including a recess communicating with said proximal end whereby a source of fluid may be placed in said recess for the transmittal of fluid to said conduit member, said conduit member including a smoothly rounded enlargement thereof set back from said distal end, a distance of between about 3/16 inch and about one inch, whereby when said enlargement is located in the cystic duct of a patient said distal end will be located in the common duct of the patient.

2. A catheter unit as claimed in claim 1 wherein said enlargement comprises an integral bead around the exterior of said conduit member.

3. A catheter unit as claimed in claim 1 wherein said enlargement is located approximately 3/8 inch from said distal end.

4. A catheter unit as claimed in claim 1 wherein said conduit member includes a substantially rigid tip portion extending from said distal end to at least the location of said enlargement.

5. A cathether unit as claimed in claim 1 wherein said adapter is bonded to the exterior surface of said conduit member.