Endosonographic Preoperative Evaluation for Tumors of the Ampulla of Vater Using Endoscopic Ultrasonography and Intraductal Ultrasonography

BACKGROUND/AIMS In recent years, endoscopic snare papillectomy has been performed to treat tumors of the ampulla of Vater. This procedure requires accurate preoperative evaluation. In this study, we diagnosed the focal extension of such tumors by using endoscopic ultrasonography (EUS) and intraductal ultrasonography (IDUS), and examined the indications for endoscopic snare papillectomy. METHODS The subjects were 48 patients with a papillary tumor (13 patients, surgical resection; 35 patients, endoscopic snare papillectomy) who were evaluated preoperatively with EUS and IDUS. The tumor-node-metastasis classification was used for the endosonographic evaluation and pathological diagnosis of these tumors. RESULTS The diagnostic accuracy of EUS was 97% for diagnosing adenomas and pTis tumors, 73% for pT1 tumors, 50% for pT2 tumors, and 50% for pT3-4 tumors, for an overall accuracy of 85% for T-staging. The diagnostic accuracy of IDUS was 94% for adenomas and pTis tumors, 73% for pT1 tumors, 50% for pT2 tumors, and 100% for pT3-4 tumors, for an overall accuracy of 80% for T-staging. CONCLUSIONS EUS and IDUS are highly capable of evaluating tumors of the ampulla of Vater preoperatively. However, these techniques are not sufficient for evaluating the focal extension of carcinomas preoperatively. Currently, endoscopic snare papillectomy is adequate for treating adenomas and pTis tumors.