[Diagnostic traps and procedure to follow in radio-invisible biliary calculi].

Instead of the term biliary microlithiasis, the authors prefer the general concept of radio-invisible biliary lithiasis. The size, the homogeneity, the site and chemical composition of the gall stones, which are the usual criteria of biliary microlithiasis, also are valid for radio-invisibility; thus the diagnostic traps are the only original characteristics of a pathology with hazy outlines, defined as one which escapes well conducted a radiological exploration. Biliary micro-lithiasis therefore raises a triple problem. The indications for biliary surgical exploration, in spite of normal cholangiography, seem to us undoubted in acute relapsing pancreatitis, once the usual medical causes have been eliminated. It should be more relative in pure biliary pain which first requires, not only repeated cholangiography, but also constant clinical and laboratory signs which suggest that the symptoms are organic and that gall stones are in formation. After laparotomy, cholecystectomy is required, not only in perceptible lithiasis, but also when the gall bladder bile contains mud, débris, sand or cholesterol spheroids. In the other cases, the choice between abstention or cholecystectomy depends on the clinical and laboratory context. The surgical attitude with regard to the common bile duct is discussed in three possibilities depending on the case, e.g. routine exploration, abstention or exploration in certain cases.