Final Results on Interventional Endoscopic Ultrasound Complications: Large Prospective Multicenter Study Ilaria Tarantino*, Carlo Fabbri, Roberto Di Mitri, Nico Pagano, Nicola Muscatiello, Luca Barresi, Filippo Mocciaro, Antonella Maimone, Mario Traina Gastroenterology, ISMETT, Palermo, Italy; Gastroenterology, bellaria, bologna, Italy; Gastroenterology, Civico, Palermo, Italy; Gastroenterology, Humanitas, Milano, Italy; Gastroenterology, Ospedale Foggia, Foggia, Italy Background an Aims: In the last decade interventional endoscopic ultrasound (EUS) procedures (celiac plexus neurolysis [CPN], pseudocyst drainage, pancreatic and biliary drainages, etc.) have widespread in clinical practice. Nevertheless, complications related to interventional EUS have not been assessed in large prospective studies. Aim of this study was to verify in a prospective, multicenter study the complication rates of interventional EUS and the risk factors related to complication. Methods: from Jan 2010 to Oct 2011 we prospectively collected data from 5 referral centers, searching for all complications related to interventional EUS. Demographics, comorbidity, drug history, and laboratory tests were collected. All patients were followed-up to 2 months. Vital signs were monitored during procedures, performed under deep sedation or general anesthesia by experienced endosonographers. Antibiotic prophylaxis was performed when indicated. Early and late complications (mild, moderate, severe, fatal) were recorded during follow-up. Results: 1118 patients (592 male), with a mean age of 63.9 14.4, underwent interventional EUS procedures: 1044 FNA (214 on cystic lesions), 43 CPN, 23 pseudocyst drainage, and 8 biliary drainage. The overall complication rate was 1.9%. Complications were: 7 fever, 4 diarrhea (all in CPN), 3 intra-cystic hemorrhages, 3 mild pancreatitis (all in FNA), 2 gastric bleeding (all in FNA), 1 epigastric pain (all in FNA), 1 desaturation. All events occurred within 5 days: mild in 17 patients and moderate in 4. All complication resolved with medical therapy. Rate of complication was 8.1% (6/74) after therapeutic procedure while 1.4% (15/1044) after EUS-FNA (p 0.001, OR 6.05, 95% CI 2.27-16.09). FNA on cystic lesions was associated with a higher risk of complications than that on solid ones (5.1% vs. 0.5%; p 0.001, OR 11.2, 95% CI 3.52-35.51). Conclusions: This study represents the first prospective, multicenter assessment on complication rates after interventional EUS procedures. Our results confirm the overall safety of EUSFNA. Nevertheless, complication of FNA on cystic lesions is higher than on solid once. Despite a higher complication rate associated with the therapeutic procedures compared to FNA, the risk is accettable taking in account the associated clinical setting.