Clip-and-band-assisted endoscopic full-thickness resection with modified purse-string closure for a duodenal gastrointestinal stromal tumor.

Duodenal gastrointestinal stromal tumors (GISTs) are rare and endoscopically challenging. We report a case of a 51-year-old man with a 13.9×13.5 mm submucosal tumor in the descending duodenum, located 3.0 cm distal to the major papilla. Endoscopic full-thickness resection (EFTR) was performed using clip-and-band-assisted traction, enabling complete en bloc removal without unintended perforation. The defect was closed with a modified purse-string suture. The key technical modification was the use of the clip delivery device as a temporary central pillar to hold encircling clips upright during nylon loop tightening, preventing inward collapse and ensuring precise edge-to-edge closure. Histopathology confirmed a very low-risk GIST (mitotic index ≤5/50 HPF; Ki-67: 5%) with negative margins (R0 resection). The patient recovered uneventfully and remained recurrence-free at 6-month follow-up. This case demonstrates that clip-and-band-assisted EFTR is feasible for selected duodenal GIST, and the clip delivery device-levered purse-string modification provides a simple, low-cost closure enhancement. However, as a single case from an expert center, the findings are not generalizable, and further studies are needed.