THERAPEUTIC ERCP IN OUTPATIENTS: A CHANGE IN PRACTICE. T.CK. Tham, I. Vandervoort, R.CK. Wong, DR. Lichtonstein, J. Van Dam, F. Ruymann, F. Farraye, D.L. Carr-Loeke. Gastroenterology Division, Brigham & Women's Hospital, Harvard Medical School, Boston, MA Patients have been routinely admitted for observation following therapeutic ERCP for potential complications. Since most complications are apparent within a few hours, outpatient therapeutic ERCP would seem feasible when certain conditions are met. AIM: To determine the safety of discharge following therapeutic ERCP. METHODS: We prospectively followed 160 patients undergoing outpatient therapeutic ERCP from a cohort of 343 consecutive ERCP procedures from 1993 1995. Patients were selected for ontpatiem therapeutic ERCP based on relative good health (ASA I or II), accommodation for a minimum of 24 hours near the hospital. They were observed for a minimum of 2 hours before discharge and were told to contact our service if any symptoms developed. RESULTS: Plastic bilia D, stents were inserted in 61 patients (indications: stricture without confirmed etiology 25, malignancy 21, chronic pancreatitis 6, selerosing eholangitis 7, cystic duct leak 2); pancreatic stents in 25 (chronic pancreatitis 12, stricture 3, stones 4, malignancy 3, miscellaneous 3); biliary sphincterotomy in 40 (choledocholitihiasis and stone extraction 36, ampullary tumor 2, sphincter of Oddi dysfunction 2); Wallstent insertion in 17 with malignant biliary obstruction, biliary balloon or catheter dilation in 8 (stricture 6, choledocholithiasis 1, sphincter of Oddi dysfunction 1); pancreatic balloon or catheter dilation in 6 (stricture 3, chronic pancrcatitis 2, pseudocyst 1); and panerea.tie sphineterotumy in 2 (chronic pancreatitis 1, stone 1). Admission was necessary in 23 (14% of outpatients); 18 (11%) of these during the 2 hour post ERCP observation period and 5 (3%) from home after a median time of 24 hours following discharge (range 5 to 48 hours). Reasons for admission were: mild pancrcatitis in 14, post-sphincterotomy bleed in 7, cholangitis in 1, pain in 1. Of the patients who were admired from home, 3 had pancreatitis (following sphincterotomy in 1, pancreatic stenting in 1, pancreatic balloon dilation in 1) and 2 had bleeds post sphincterotomy. The overall median hospital stay was 3 days (range 1 17) and all patients recovered with conservative treatment. CONCLUSIONS: A policy of selected outpatient therapeutic ERCPs, with admission reserved for those with a complication, appears to be safe and costeffective.