Value of endoscopic ultrasonography to prevent retained calculus in common bile duct post-laparoscopic cholecystectomy CHEN Liu-hua*, WU Zhi-mian, ZHENG Chao-xu, et al. *Department of Minimal Invasive Surgery, the First Affiliated Hospital of SUN Yat-sen University, Guangzhou 510080, China Corresponding author：CHEN Liu-hua, E-mail：chlh22@163.com Abstract Objective To evaluate the rate of final diagnosis of common bile duct (CBD) stones pre-laparoscopic cholecystectomy (LC) and to decrease retained calculus in CBD post-LC. Methods From January 2004 to July 2007, 100 symptomatic gallstones patients performed endoscopic ultrasonography (EUS) for suspected choledocholithiasis pre-LC at the First Affiliated Hospital of Sun Yat-sen University. The EUS results were analyzed. Results The successful rate of EUS were 100%. Occult CBDS were found in 54 patients . The sensitivities, specificities, accuracies, positive and negative predictive values for occult CBDS by EUS were 96.30%，97.83%，97.00%，98.11% and 95.74%. Conclusion EUS is necessary for patients to decrease the rate of retained calculus in CBD post-LC.