Abstract:To evaluate the efficacy and safety of endoscopic submucosal dissection (ESD) for rectal neuroendocrine tumor (RNET). Data of 71 patients (43 males and 28 females, aged 46.66±10.15 years) with histologically diagnosed RNET ≤15 mm in diameter who underwent ESD in Department One of Gastroenterology, Digestive Diseases Hospital, Heilongjiang Provincial Hospital from December 2012 to January 2021 were retrospectively analyzed. Epidemiological characteristics, endoscopic characteristics, the operation time, complications, pathology results, the consistency of endoscopic ultrasound (EUS) and pathology and prognosis were analyzed. Sixty-nine patients had single lesion and 2 patients had multiple lesions (two of each). Seventy lesions (70/73, 95.89%) were located in the middle-lower rectal segment, and 3 lesions (3/73, 4.11%) in the upper segment. The maximum diameter was 8.54±3.12 mm. The en bloc resection rate was 100%. No adverse event was observed. The R0 resection rate was 87.67% (64/73), with 8 had undetermined vertical resection margin and 1 had lymphovascular invasion. EUS showed no case involving the muscularis propria with pathologic coincidence rate of 100.0%. The follow-up period was 4.52±3.85 years (1-9 years). No local recurrence or distant metastasis was found. ESD is safe and effective in RNET ≤15 mm in diameter. For tumors of G1 without metastasis in preoperative evaluation, close follow-up seems to be a feasible option with lymphovascular invasion or undetermined margin after ESD.