<b>Background</b> Many patients with familial adenomatous polyposis (FAP) have adenomatous polyps of the duodenum and the jejunum. We aimed to elucidate the long-term outcomes after double-balloon endoscopy (DBE)-assisted endoscopic resection of duodenal and jejunal polyps in patients with FAP.
<b>Methods</b> We retrospectively reviewed patients who underwent more than two sessions of endoscopic resection using DBE from August 2004 to July 2018.
<b>Results</b> A total of 72 DBEs were performed in eight patients (median 30 years old, range 12-53, 1.4 DBE procedures/patient-year) during the study period and 1237 polyps were resected. The median observation period was 77.5 months (range 8 to 167). There were 11 adverse events, including 7 with delayed bleeding and 4 with acute pancreatitis. No delayed bleeding occurred after cold polypectomy. Although one endoscopically-resected polyp in the duodenum was diagnosed as intramucosal carcinoma in one patient, no patient developed an advanced duodenal or jejunal cancer during the study period.
<b>Conclusions</b> Endoscopic resection of duodenal and jejunal polyposis using DBE in patients with FAP can be performed safely, efficiently and effectively.