AIM:To assess the outcome of patients with acute necrotizing pancreatitis treated by percutaneous drainage with special focus on the influence of drainage size and number.METHODS:We performed a retrospective analysis of 80 patients with acute pancreatitis requiring percutaneous drainage therapy for infected necroses.Endpoints were mortality and length of hospital stay.The influence of drainage characteristics such as the median drainage size,the largest drainage size per patient and the total drainage plane per patient on patient outcome was evaluated.RESULTS:Total hospital survival was 66%.Thirty-four patients out of all 80 patients (43%) survived acute necrotizing pancreatitis with percutaneous drainage therapy only.Eighteen patients out of all 80 patients needed additional percutaneous necrosectomy (23%).Ten out of these patients required surgical necrosectomy in addition,6 patients received open necrosectomy without prior percutaneous necrosectomy.Elective surgery was performed in 3 patients receiving cholecystectomy and one patient receiving resection of the parathyroid gland.The number of drainages ranged from one to fourteen per patient.The drainage diameter ranged from 8 French catheters to 24 French catheters.The median drainage size as well as the largest drainage size used per patient and the total drainage area used per patient did not show statistically significant influence on mortality.CONCLUSION:Percutaneous drainage therapy is an effective tool for treatment of necrotizing pancreatitis.Large bore drainages did not prove to be more effective in controlling the septic focus.