ORIGINAL ARTICLE Single-step EUS-guided transmural drainage of simple and complicated pancreatic pseudocysts Mainor R. Antillon, MD, Raj J. Shah, MD, Gregory Stiegmann, MD, Yang K. Chen, MD Denver, Colorado, USA Background: Single-step EUS-guided transmural drainage of pseudocysts has been reported, but there are no published prospective studies on clinical outcomes. Objective: To assess the safety and the efficacy of single-step EUS-guided placement of large endoprostheses to treat simple and complicated pseudocysts. Design: Prospective cohort study. Setting: Single tertiary referral center. Patients: Consecutive patients referred for management of symptomatic chronic pancreatic pseudocysts O4 cm in size. Interventions: Single-step EUS-guided transmural pseudocyst drainage performed with a linear-array echoen- doscope for placement of 10F stents in adults and 7F stents in children. Main Outcome Measures: Complete or partial (O50% reduction) resolution of pseudocyst on follow-up im- aging, recurrence, clinical response, and procedure-related complications. Recurrence was defined as the reap- pearance of a pancreatic pseudocyst in the same location. Results: There were 33 patients, with a mean age of 43 years. Median pseudocyst size was 8.5 cm (range, 4-20 cm). Fourteen patients (42%) had infected pseudocysts, 8 patients (24%) had gastric varices, and 16 patients (48%) had no visible endoscopic bulge. Stent placement was successful in 31 patients (94%). Twenty-seven pa- tients (82%) had complete resolution of a pseudocyst; 4 patients (12%) had partial resolution, with symptom relief. There were 2 major complications and 3 minor complications. Recurrence of a pseudocyst was observed in only 1 patient over a median follow-up of 46 weeks. Limitations: No randomized treatment arm comparing this technique with conventional endoscopic drainage. Conclusions: Single-step EUS-guided transmural drainage with large endoprostheses is a safe and effective therapy for patients with simple and complicated pancreatic pseudocysts. (Gastrointest Endosc 2006;63:797- 803.) Endoscopic drainage of symptomatic pancreatic pseu- docysts is a proven treatment and can be performed via a transpapillary and/or transmural approach. 1,2 There is general agreement that optimal drainage of large pseudo- cysts is best accomplished by placing multiple large-caliber stents. The conventional technique uses a duodenoscope with fluoroscopic guidance, and gastric varices or non- bulging pseudocysts are usually considered contraindica- tions for transmural drainage. With the introduction of EUS, EUS-assisted drainage has been advocated for added safety, by allowing proper selection of an optimal site for the needle puncture, thus avoiding major vessels and adjacent structures. How- ever, this technique requires a sequential approach. 3 Ini- tially, an echoendoscope is used to evaluate the pseudocyst and surrounding structures and to identify the best site for drainage. Then a duodenoscope with a 4.2-mm operating channel is used with fluoroscopic guidance for placement of large endoprostheses. This se- quential approach likely increases procedure time as well as cost. Furthermore, when switching from echoendo- scope to duodenoscope, the best angle of puncture can- not be assured. Real-time EUS monitoring of the Copyright ª 2006 by the American Society for Gastrointestinal Endoscopy 0016-5107/$32.00 doi:10.1016/j.gie.2005.10.025 www.giejournal.org Volume 63, No. 6 : 2006 GASTROINTESTINAL ENDOSCOPY 797