Population-Based Studies Should not be Used to Justify a Policy of Routine Cholangiography to Prevent Major Bile Duct Injury During Laparoscopic Cholecystectomy.

Iatrogenic bile duct injury at time of cholecystectomy is a rare but devastating event. A twofold higher frequency of bile duct injury during cholecystectomy without cholangiography is reported in population-based studies. Some interpret this as a cause-and-effect relationship and thus mandate routine cholangiography. A critical appraisal of population studies is required to determine whether these studies are suitable in determining the role of routine cholangiography. The literature search was performed using combinations of the forced search terms "duct injury", "population" and "cholangiography" to identify population-based studies assessing the relationship between cholangiography and iatrogenic bile duct injury. All seven population-based studies reported a numerically higher rate of bile duct injury when an intraoperative cholangiogram was not obtained during cholecystectomy. Five predate the critical view technique. Only one was limited to laparoscopic cholecystectomy. All studies identified cholangiography as a likely marker for disease severity or surgical technique. Six studies did not demonstrate a cause-and-effect relationship by not including effect modifiers. The only study to address confounders reported the same rate of injury irrespective of the use of cholangiography. Critical appraisal of population-based studies does not support their use in justifying a policy of routine cholangiography to prevent major bile duct injury.