What's right when the gallbladder's left? A case report.

During laparoscopic cholecystectomy for cholelithiasis in a 40-year-old woman, we came upon a case of incidentally discovered left-sided gallbladder (LSG). Two anatomic variants of LSG are known: (a) "true LSG," in which, according to Gross, an accessory gallbladder originates from the left hepatic duct (LHD), the right embryonic bud is readsorbed, and the cystic duct joins either the CBD from the left or the LHD directly. Otherwise, a normal right-sided gallbladder adheres to the inferior left hepatic lobe, and the cystic duct joins the CBD from the right side (as in our case); (b) gallbladder under the fourth hepatic segment, medial to a right-sided round ligament, probably resulting from a prenatal obliteration of the right umbilical vein. Left-sided gallbladder is a paraphysiologic condition that when identified before surgery, must be studied by CT or MRI, when incidentally discovered during surgery must be promptly recognized by the surgeon, who must be aware of the unpredictable confluence of the cystic duct into the CBD. The following operative precautions are useful for avoiding a lesion of the CBD: The surgeon should start dissection of Calot's triangle as close as possible to the gallbladder margin, prepare and clip the cystic duct as close as possible to the infundibulum, and a 30 degrees angled telescope. If in doubt, the surgeon should perform an intraoperative cholangiography.