Stones or clots in the biliary tract. A diagnostic dilemma.

Clots, which not uncommonly form in the biliary tract, may cause diagnostic errors. They often result from minor hemobilia, small hemorrhages into the ducts, mostly occurring in connection with gallstone attacks or biliary surgery. Hemobilia may also, as hematuria and epistaxis, complicate anticoagulant therapy. The blood will generally flow inconspicuously into the intestine, and even if it coagulates, the clots tend to dissolve rapidly through the fibrinolytic activity of the bile. For various reasons they may occasionally escape dissolution and remain in the ducts. fibrin clots can also form in inflammatory biliary tract disease. Clots will easily be mistaken for gallstones and treated as such. Cases are presented which illustrate why they are so often overlooked or misinterpreted. Cholangiography may be of diagnostic help since the clots show certain characteristics, appearing as casts of the biliary tract, often adhering to the walls, sometimes with indistinct borderlines. During 1980 we performed 128 cholecystectomies for suspected gallstone disease. Common duct exploration was done in 18 because of contrast defects in the cholangiogram. In 15 cases these were due to gallstones, in 3--one out of six--they were caused by blood clots. The comparatively high frequency with which clot formation in the biliary tract is observed when attention is given to this possibility, compared to the number of misinterpretations that otherwise occur leads to the conclusion that common duct clots are more common and of greater significance than is generally assumed.