Abstract:Objective To compare the diagnostic value of longitudinal-endoscopic ultrasonography (L-EUS) and mini-probe endoscopic ultrasonography (MPS) in submucosal tumors (SMT) of the descending part of the duodenum.Methods The clinical data of 81 patients with submucosal tumors of the descending duodenum who underwent endoscopic resection from January 2016 to December 2019 were collected retrospectively. Preoperative evaluation with L-EUS or MPS was performed in L-EUS group (n = 40) and MPS group (n = 41). According to the gold standard of postoperative pathology, the diagnostic coincidence rates of the two methods for SMT of the descending duodenum were compared.Results The diagnosis rate of the L-EUS group was 82.5%. The diagnosis rate of the MPS group was 61.0%. There was significant difference between the two groups (P = 0.048). Subgroup analysis showed that when the lesion size over 10.0 mm, the diagnosis rate of L-EUS group was better than that of MPS group (84.0% vs 47.6%, P = 0.012). When the lesion size was less than 10.0 mm, the diagnostic coincidence rate of the L-EUS group was higher than that of the MPS group (80.0% vs 75.0%, P > 0.05), but the difference was not statistically significant. Regardless of whether the lesions were located in the ventral or non-ventral side of the ampulla, there was no significant difference in the coincidence rate of diagnosis between the two groups (P > 0.05). The proportion of pharynx pain and discomfort after examination in L-EUS group and MPS group was 7.5% (3/40) and 2.4% (1/41), respectively, and there was no significant difference between the two groups (P > 0.05), and there was no adverse event of bleeding and perforation in the process of ultrasound examination in both groups.Conclusion The diagnostic rate of L-EUS in descending SMT of duodenum is higher than that of MPS, especially when the lesion is larger than 10 mm, L-EUS is more effective in diagnosis of duodenal SMT.