Endoscopic submucosal dissection and full-thickness resection are effective for select duodenal lesions but carry significant risks.

• Technical success rate was 98.2%, with R0 resection rates at 93.3% for epithelial and 90.4% for subepithelial lesions.
• Intraprocedural bleeding occurred in 16.5%; perforation rate was 5.5%, all manageable endoscopically.

Consider severe fibrosis a key predictor for adverse events, particularly with ulceration in subepithelial lesions.

• A structured closure approach achieved 97.2% complete closure and minimized delayed complications to 2.8%.