Acute cholecystitis: preoperative CT can help the surgeon consider conversion from laparoscopic to open cholecystectomy.

PURPOSE: To establish whether preoperative computed tomographic (CT) findings in patients with acute cholecystitis were associated with conversion from laparoscopic to open cholecystectomy in patients with calculous acute cholecystitis.
MATERIALS AND METHODS: The study protocol was approved by the local institutional review board, and written informed consent was provided by all patients at enrollment. From 2008 to 2010, all patients admitted to a university medical center with acute calculous cholecystitis and for whom a preoperative contrast material-enhanced CT study was available were prospectively included. Cholecystectomy was always initiated laparoscopically. To identify risk factors for conversion specifically related to acute cholecystitis, CT studies were analyzed according to predefined criteria by two radiologists who were blinded to the patient's conversion status. Associations between conversion and radiologic findings were assessed by using univariate and multivariate logistic models.
RESULTS: A total of 108 patients were analyzed (61 men, 47 women; median age, 58 years; age range, 17-88 years). Conversion occurred in 24 (22%) cases. On preoperative CT images, the absence of gallbladder wall enhancement was associated with the presence of gangrenous acute cholecystitis (sensitivity, 73%). The absence of gallbladder wall enhancement (58% and 40% for conversion and nonconversion, respectively; P = .02) and the presence of a gallstone in the gallbladder infundibulum (78% and 22% for conversion and nonconversion, respectively; P = .04) were associated with acute cholecystitis-related conversion in a multivariate analysis. Interobserver agreement for CT study interpretation was very good (median k value, 0.92; range, 0.76-1.00).
CONCLUSION: The absence of gallbladder wall enhancement (associated with the presence of gangrenous acute cholecystitis) and the presence of a gallstone in the gallbladder infundibulum are associated with conversion from laparoscopic to open cholecystectomy. © RSNA, 2012.