Performance characteristics of EUS for locoregional evaluation of ampullary lesions

BackgroundThe accuracy of EUS in the locoregional assessment of ampullary lesions is unclear.ObjectivesTo compare EUS with ERCP and surgical pathology for the evaluation of intraductal extension and local staging of ampullary lesions.DesignRetrospective cohort study.SettingTertiary-care referral center.PatientsAll patients who underwent EUS primarily for the evaluation of an ampullary lesion between 1998 and 2012.InterventionEUS.Main Outcome MeasurementsComparison of EUS sensitivity/specificity for intraductal and local extension with ERCP and surgical pathology by using the area under the receiver-operating characteristic (AUROC) curves and outcomes of the subgroup referred for endoscopic papillectomy.ResultsWe identified 119 patients who underwent EUS for an ampullary lesion, of whom 99 (83%) had an adenoma or adenocarcinoma. Compared with ERCP (n = 90), the sensitivity/specificity of EUS for any intraductal extension was 56%/97% (AUROC = 0.77; 95% confidence interval [CI], 0.64-0.89). However, when using surgical pathology as the reference (n = 102), the sensitivity/specificity of EUS (80%/93%; AUROC = 0.87; 95% CI, 0.76-0.97) and ERCP (83%/93%; AUROC = 0.88; 95% CI, 0.77-0.99) were comparable. The overall accuracy of EUS for local staging was 90%. Of 58 patients referred for endoscopic papillectomy, complete resection was achieved in 53 (91%); in those having intraductal extension by EUS or ERCP, complete resection was achieved in 4 of 5 (80%) and 4 of 7 (57%), respectively.LimitationRetrospective design.ConclusionsEUS and ERCP perform similarly in evaluating intraductal extension of ampullary adenomas. Additionally, EUS is accurate in T-staging ampullary adenocarcinomas. Future prospective studies should evaluate whether EUS can identify characteristics of ampullary lesions that appropriately direct patients to endoscopic or surgical resection.