The Role of Intraductal Ultrasonography on the Detection of Small Remnant Stones and Their Differentiation from Air-Bubbles, after Endoscopic Papillary Balloon Dilatation

Shim, Chan Sup; Lee, Moon Sung; Cho, Young Deok; Moon, Jong Ho

Abstract

BACKGROUND AND AIMS
A cholangiogram, immediately taken after bile duct stone removal, does not always provide adequate information about the presence of fragmented small stones in the bile duct, due to a large amount of bowel gas around the commom bile duct (CBD) or air-bubbles in the bile duct. We performed this study to evaluate the clinical usefulness of intraductal ultrasonography (IDUS) on the detection of small remnant stones after endoscopic papillary balloon dilatation (EPBD). METHODS: Among the 42 patients treated with EPBD for the removal of CBD stones, 19 patients who had undergone ESWL or mechanical lithotripsy with basket, were evaluated by IDUS for the detection of remnant bile duct stones. RESULTS: 17 out of 19 (89.5%) patients were successfully performed IDUS. Among the 17 patients, 13 showed no definite stones on cholangiogram, but CBD stones were detected using IDUS in 4 patients (30.7%). Among the 4 whose cases were difficult to differentiate air-bubbles from stones on a cholangiogram, 3 patients were diagnosed as having air-bubbles and 1 patient was diagnosed as having stones, through IDUS. During the process of conducting IDUS 19 times, one ultrasonic miniature probe was damaged. CONCLUSIONS: IDUS is very effective in detecting remnant small bile duct stones that are occasionally undetected on cholangiogram, and in differentiating stones from air-bubbles just after the removal of stones using EPBD. More efforts, however, are needed to improve the durability of the ultrasonic miniature probe.