THE UNSUSPECTED SMALL STONE STUDY (USSS)

描述（改编自应用程序）

DESCRIPTION (adapted from the application) Gallstones are the most common and the most costly digestive disease, with an annual estimated expenditure of 5 billion dollars. Fifteen percent of persons with symptomatic gallstones will have concomitant bile duct stones (BDS). Expert opinion varies, but there are several reports of leaving BDS in situ without adverse outcomes. The aim of this proposal is to determine if conservative or expectant management is a safe and effective therapy for patients with unsuspected small BDS found at intraoperative cholangiography (10C) during laparoscopic cholecystectomy (LC), compared to conventional therapy with endoscopic retrograde cholangiopancreatography (ERCP) and sphincterotomy (ES). This is a randomized, prospective, multicenter study of patient outcomes and treatment costs. The primary endpoint is overall morbidity I year after randomization. Secondary endpoints include rates of severe morbidity, mortality, abdominal pain, jaundice, abnormal serum liver tests, abnormal transcutaneous abdominal ultrasound examinations, quality of life indices, and overall treatment costs. A database will be established for long-term follow up. The duration of the study is aimed to be 2 years from the onset of funding. One hundred and eighty two (91 per group) patients will be randomized to have expectant management or to have ERCP with sphincterotomy and stone extraction. Eligibility requirements include no history of jaundice, pancreatitis, or cholangitis, and <3 BDS, < 5 mm in diameter found by intraoperative imaging. Follow up will be by standardized interview at 1, 6, and 12 months. Persons in the both expectant and treatment groups will have serum liver tests at 6 and 12 months, post-LC or post-ERCP respectively. The expectantly managed group will have transabdominal ultrasound at 12 months. Expectantly managed individuals with abnormal results will have ERCP. Statistical power for detecting differences will be emphasized (beta=0.01, alpha=0.05). This proposal will allow the investigators to explore an important clinical question, expand a previously constructed study framework to become an interdisciplinary study group including gastroenterologists and surgeons, and to refine and validate study operational systems. Should there be nonsignificant trends detected in the results with the proposed sample size, we intend to proceed with a larger scale multicenter study proposal. The study group and systems developed in this proposal will be used for future multicenter projects on gallstone disease.