Evaluation of endoscopic resectability for ampullary tumors by EUS and side-viewing duodenoscopy.

Background and Objectives: Accurate preoperative assessment of ampullary tumors is vital in planning an appropriate endoscopic papillectomy strategy. The use of EUS and side-viewing duodenoscopy (SVD) with narrow band imaging (NBI) varies across studies. Reports on critical features under EUS and SVD + NBI are lacking. We aimed to demonstrate (1) the theoretical and real-world management of ampullary lesions, (2) the implementation of preresection biopsy or fine needle aspiration (FNA), and (3) critical features under EUS and SVD + NBI for preoperative assessment. Methods: Data from consecutive patients with suspected papillary lesions referred for EUS and SVD + NBI from January 2020 to December 2023 were retrospectively analyzed. The primary outcomes were the difference between theory and reality for management for ampullary nontumor-adenoma-adenocarcinoma, and the high-risk features under EUS and SVD + NBI for adenocarcinoma, T1 stage and ductal invasion. The secondary outcomes were the value of preoperative biopsy and FNA. Results: A total of 121 patients with suspected ampullary tumors were included in the analysis. Less than half (27.40%) of the patients in the surgery group could have been classified as endoscopically resectable. A total of 46.4% and 35% of the biopsy and FNA pathological results, respectively, were inconsistent with the postoperative results. Protrusion with atypical ulcers, NBI type III, EUS size ≥3.0 cm, hypoechoicity, poor blood supply, and EUS ductal invasion were high-risk factors for adenocarcinoma. A size ≥3.0 cm and hypoechoic status were high-risk factors for T1 and ductal invasion. The cutoff value of the stain ratio for adenocarcinoma was 5.35, with a sensitivity, specificity, and accuracy of 88.5%, 93.0%, and 90.8%, respectively. Conclusions: Preoperative assessment of ampullary tumors is necessary, but biopsy and FNA are not sufficient. EUS and SVD + NBI, which focus on essential features, are valuable for evaluating ampullary tumors for endoscopic resectability.