Original article Single-step versus two-step endo–ultrasonography-guided drainage of pancreatic pseudocyst Benedetto MANGIAVILLANO,* Paolo Giorgio ARCIDIACONO, † Enzo MASCI,* Alberto MARIANI, † Maria Chiara PETRONE, † Silvia CARRARA, † Sabrina TESTONI † & Pier Alberto TESTONI † *Division of Gastrointestinal Endoscopy, San Paolo University Hospital, and † Division of Gastroenterology & Gastrointestinal Endoscopy, Università Vita-Salute San Raffaele, Scientific Institute San Raffaele, Milan, Italy OBJECTIVE: The aim of this prospective study was to compare the feasibility, technical success rate and com- plication between single-step endo-ultrasonography (EUS)-guided and two-step EUS-guided drainage technique for symptomatic pancreatic pseudocyst (PP). METHODS: Twenty-one PP patients with clear intra- cystic fluid that needed to be drained were divided into two groups, depending on the availability of the therapeutic echoendoscope at the time of the procedure: Group 1 (13 patients) underwent a single- step EUS-guided endoscopic drainage and Group 2 (8 patients) underwent a two-step EUS-guided drainage technique. RESULTS: In Group 1 immediate technical success was achieved in 92.3% (12/13); two patients had recurrent PP and both were successfully treated by a second EUS-guided drainage. Clinical success was achieved in all cases. In Group 2 technical success was achieved in 75.0% of the patients (6/8). One patient (12.5%) bled 36 h after the procedure. Five out of 6 patients had long-term success. Clinical success was significantly greater in Group 1 (P < 0.05). CONCLUSION: The technique of single-step EUS- guided drainage was superior to the technique of a two-step EUS-guided drainage technique for PP drainage. KEY WORDS: endoscopic drainage, endo-ultrasonography, pancreatic pseudocysts. INTRODUCTION Pancreatic pseudocyst (PP) is a cystic cavity bound to the pancreatic gland by inflammatory epithelium. Well-defined granulation tissue distinguishes PP from peripancreatic fluid collection. PP is either acute or chronic, both containing pancreatic juice, but the former is a consequence of acute pancreatitis (AP) or pancreatic trauma, while the latter follows chronic pancreatitis (CP), with or without a documented attack of AP. 1 Most peripancreatic fluid collections due to AP resolve spontaneously, whereas after CP, PPs rarely regress when they are larger than 6 cm in diameter. 2,3 Per- sistent symptoms, rapid enlargement and cyst-related complications like infection or common bile duct compression are indications for PP drainage. 4,5 Correspondence to: Paolo Giorgio ARCIDIACONO, Division of Gastroenterology & Gastrointestinal Endoscopy, Università Vita-Salute San Raffaele, Scientific Institute San Raffaele, Via Olgettina 62, 20132, Milan, Italy. Email: arcidiacono.paologiorgio@hsr.it  2011 The Authors Journal of Digestive Diseases  2011 Chinese Medical Association Shanghai Branch, Chinese Society of Gastroenterology, Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine and Blackwell Publishing Asia Pty Ltd. Journal of Digestive Diseases 2012; 13; 47–53 doi: 10.1111/j.1751-2980.2011.00547.x 47