Transduodenal ampullectomy is an effective surgical exploration procedure for unexplained dilation of the cholangiopancreatic duct.

Background: The clinical diagnosis and treatment of dilation of the cholangiopancreatic duct in patients with ambiguous ampullary disease, termed unexplained dilation of the cholangiopancreatic duct (UDCD), is commonly difficult. This study aimed to evaluate the applicability of transduodenal ampullectomy (TDA) for the diagnosis and treatment of UDCD.

Methods: We first proposed a surgical exploration procedure based on the TDA and applied it in a representative UDCD patient. We retrospectively analyzed the pathological diagnosis and prognosis of 14 patients at our hospital and 189 patients reported in existing studies who were treated with TDA between January 2010 and December 2022.

Results: TDA can be used to radically explore the ampullary region and harvest adequate pathological tissue, which is helpful for identifying the cause of UDCD. The diagnostic rate of intraoperative frozen pathology was greater than that of preoperative endoscopic biopsy (78.41% vs. 65.94%, P = 0.044). The postoperative complication rate was 27.07%, with a mortality rate of 0.00%. The 5-year survival rate was 68.31% in patients with adenocarcinoma, 85.99% in patients with adenoma with HGD/pTis, and 100% in patients with benign lesions, and these had a statistically significant difference (P = 0.021).

Conclusions: TDA-based surgical exploration can be used as a safe and effective transitional procedure in the treatment of UDCD.