The value of percutaneous ultrasound in predicting conversion from laparoscopic to open cholecystectomy due to acute cholecystitis

Laparoscopic cholecystectomy has become the treatment of choice for gallstone disease. Advantages of the laparoscopic approach include lower morbidity and mortality rates, reduced length of hospital stay, and earlier return to work. In acute cholecystitis, severe inflammation makes laparoscopic dissection technically more demanding, with a higher risk of related complications that require conversion to open cholecystectomy. We reviewed the records of 5,596 patients who underwent cholecystectomy between 1993 and 2011 in a single institution. A laparoscopic approach was undertaken in 4,105 patients (73.4 %). The ultrasound signs of acute cholecystitis were found in 542 patients (13.2 %) who underwent laparoscopic cholecystectomy. We analyzed the ultrasound presentations of acute cholecystitis in patients who required conversion to open cholecystectomy and compared them with the ultrasound signs of acute cholecystitis in patients who had a completed laparoscopic cholecystectomy. A conversion to open cholecystectomy in patients with acute cholecystitis was necessary in 24 % (n = 130) of the patients compared to 3.4 % of the patients with uncomplicated gallstone disease. The most frequent ultrasound findings in patients requiring conversion were a pericholecystic exudate in 42 %, a difficult identification of anatomical structures due to local severe inflammation in 34 %, and gallbladder wall thickening of > 5 mm in 31 %. Additionally, when the duration of symptoms exceeded 3 days, more than half of the patients required conversion to open cholecystectomy and the conversion rate was fivefold higher than for those with a shorter duration of acute cholecystitis. In patients with severe acute cholecystitis found on ultrasound, combined with gallbladder wall thickening to > 5 mm, pericholecystic exudates or abscess adjacent to the gallbladder, difficulty identifying anatomical structures within Calot's triangle, specifically when the duration of symptoms exceeds 3 days, cholecystectomy should be done as an open approach because of the high risk of conversion.