PROSPECTIVE CONTROLLED-STUDY OF ENDOSCOPIC ULTRASONOGRAPHY AND ENDOSCOPIC RETROGRADE CHOLANGIOGRAPHY IN PATIENTS WITH SUSPECTED COMMON-BILEDUCT LITHIASIS

Background Endoscopic sphincterotomy is sometimes done unnecessarily i n patients with suspected choledocholithiasis. Our aims were to assess the diagnostic accuracy of endoscopic ultrasonography and endoscopic retrograde cholangiography (ERC) and to find out whether endoscopic ul trasonography may help to prevent unnecessary sphincterotomy or surgic al explorations. Methods We recruited 119 patients aged 70.4 (SD 16.1) years with strongly suspected choledocholithiasis who presented to ou r endoscopy unit between January, 1994, and January, 1995. During the same spell of sedation or within 2 h of each other, endoscopic ultraso nography and ERC were carried out by investigators unaware of the pati ent's history. Endoscopic sphincterotomy with instrumental exploration was then done as the gold standard for the presence or the absence of stones. Findings 78 (66%) patients had choledocholithiasis; 17 (14%) had other bileduct diseases; 24 (20%) had a clear bileduct or did not require an invasive endoscopic procedure. The sensitivity of endoscopi c ultrasonography was 93%, specificity 97%, positive predictive value 98%, and negative predictive value 88%. The corresponding values for E RC were 89%, 100%, 100%, and 83%. There were five false-negative cases by endoscopic ultrasonography (of which three were also negative with ERC) and one false-positive. The morbidity rate was 4.1%. Interpretat ion We conclude that endoscopic ultrasonography is at least as sensiti ve as ERC. Endoscopic ultrasonography may prevent inappropriate invasi ve explorations of the common bileduct.