Laparoscopic intraoperative ultrasonography reduces the need for preoperative MRCP and ERCP in high- and moderate-risk patients with suspected choledocholithiasis

Background: Despite the existing guidelines the optimal management of suspected choledocholithiasis is still under debate. The aim of the study was the evaluation of laparoscopic ultrasound (LUS) as a rational alternative to preoperative magnetic resonance cholangio-pancreatography (MRCP) in the visualization of choledocholithiasis and in a more selective application of endoscopic retrograde cholangio-pancreatography (ERCP). Materials and Methods: Clinical and radiological data of urgently admitted patients were collected prospectively during a five-year period. Only high- and intermediate-risk patients according to the American Society for Gastrointestinal Endoscopy guidelines were included and their data analyzed. Results: In total, 297 patients underwent laparoscopic treatment and LUS. Preoperative MRCP was done in 87 of all. Bile duct dilatation was more evident while performing LUS compared to preoperative MRCP - 67% vs. 43.7% respectively. Bile duct size significantly correlated with choledocholithiasis using both methods; however, the Pearson correlation coefficient was higher in LUS (r = 0.511; p < 0.001) compared to MRCP (r = 0.432; p < 0.001). Choledocholithiasis was more frequently diagnosed by LUS in both groups, compared to preoperative MRCP - 35.8% and 75.5% vs. 26% and 53.1%, respectively, p < 0.001. The laparoscopic approach with LUS proved that in 24.5% of high-risk patients avoiding unnecessary preoperative ERCP is possible. Contrary to that, preoperative MRCP was associated with 38.3% (23) of false negative cases. The application of LUS significantly improved the visualization of small stones, 3 mm (IQR 3-1) vs. 5 mm (IQR 7-4), visualized by LUS and MRCP accordingly, p < 0.001. Sensitivity, specificity, positive and negative predictive values of MRCP and LUS were comparable. Conclusion: The application of LUS in high- and moderate-risk patients with suspected choledocholithiasis is a rational approach. It substantially decreases the need for preoperative MRCP in cases of small stones, also decreasing the incidence of false indications for ERCP.