Association between cholecystectomy with vs without intraoperative cholangiography and risk of common duct injury

IMPORTANCE: Significant controversy exists regarding routine intraoperative cholangiography in preventing common duct injury during cholecystectomy. OBJECTIVE: To investigate the association between intraoperative cholangiography use during cholecystectomy and common duct injury. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort study of all Texas Medicare claims data from 2000 through 2009. We identified Medicare beneficiaries 66 years or older who underwent inpatient or outpatient cholecystectomy for biliary colic or biliary dyskinesia, acute cholecystitis, or chronic cholecystitis.We compared results from multilevel logistic regression models to the instrumental variable analyses. INTERVENTIONS: Intraoperative cholangiography use during cholecystectomy was determined at the level of the patients (yes/no), hospitals (percentage intraoperative cholangiography use for all cholecystectomies at the hospital), and surgeons (percentage use for all cholecystectomies performed by the surgeon). Percentage of use at the hospital and percentage of use by surgeon were the instrumental variables. MAIN OUTCOMES AND MEASURES: Patients with claims for common duct repair operations within 1 year of cholecystectomy were considered as having major common duct injury. RESULTS: Of 92 932 patients undergoing cholecystectomy, 37 533 (40.4%) underwent concurrent intraoperative cholangiography and 280 (0.30%) had a common duct injury. The common duct injury rate was 0.21% among patients with intraoperative cholangiography and 0.36%among patients without it. In a logistic regression model controlling for patient, surgeon, and hospital characteristics, the odds of common duct injury for cholecystectomies performed without intraoperative cholangiography were increased compared with those performed with it (OR, 1.79 [95%CI, 1.35-2.36]; P < .001). When confounding was controlled with instrumental variable analysis, the association between cholecystectomy performed without intraoperative cholangiography and duct injury was no longer significant (OR, 1.26 [95%CI, 0.81-1.96]; P = .31). CONCLUSIONS AND RELEVANCE: When confounders were controlled with instrumental variable analysis, there was no statistically significant association between intraoperative cholangiography and common duct injury. Intraoperative cholangiography is not effective as a preventive strategy against common duct injury during cholecystectomy.