Underwater endoscopic mucosal resection for superficial nonampullary duodenal adenomas.

BACKGROUND AND STUDY AIM:  Underwater endoscopic mucosal resection (UEMR) was recently developed in a Western country. A prospective cohort study to investigate the effectiveness of UEMR was conducted in patients with small superficial nonampullary duodenal adenomas.

PATIENTS AND METHODS:  Patients with duodenal adenomas ≤ 20 mm were enrolled. After the duodenal lumen had been filled with physiological saline, UEMR was performed without submucosal injection. Endoclip closure was attempted for all mucosal defects after UEMR. Follow-up endoscopy with biopsy was performed 3 months later. The primary end point was the complete resection rate, defined as neither endoscopic nor histological residue of adenoma at the follow-up endoscopy.

RESULTS:  30 patients with 31 lesions were enrolled. The mean (SD) tumor size was 12.0 mm (7.3). The complete resection rate was 97 % (90 % confidence interval, 87 % - 99 %). The en bloc resection rate was 87 %. All mucosal defects were successfully closed by endoclips. No adverse events occurred except for one case of mild aspiration pneumonia.

CONCLUSIONS:  UEMR is efficacious for the treatment of small duodenal adenomas, but further large-scale trials are warranted to confirm these results.