Intraoperative pancreatoscopy with the ultrathin pancreatoscope for mucin-producing tumors of the pancreas.

OBJECTIVE To evaluate the diagnostic accuracy of intraoperative pancreatoscopy with the ultrathin pancreatoscope for the main pancreatic lesions of mucin-producing tumors of the pancreas (MPT). DESIGN Prospective diagnostic test study with a criterion standard of pathologic examination and masked comparison. SETTING A university hospital. PATIENTS Twenty-four consecutive patients with MPT referred for surgery in whom endoscopic retrograde pancreatography, endoscopic ultrasonography, and computed tomography had been performed as a diagnostic examination. All patients underwent surgery and the diagnosis was confirmed by pathologic examination. INTERVENTION Intraoperative pancreatoscopy was performed with the ultrathin pancreatoscope. MAIN OUTCOME MEASURES Findings of intraoperative pancreatoscopy, endoscopic retrograde pancreatography, and endoscopic ultrasonography were confirmed by pathologic examination of resected specimens. The diagnostic accuracy of these 3 modalities in detection of MPT lesions in the main pancreatic duct was compared. RESULTS The diagnostic criterion of MPT lesions in the main pancreatic duct by intraoperative pancreatoscopy was a granular and papillary mural nodule. An MPT lesion in the main pancreatic duct was found in 17 of 24 cases. Intraoperative pancreatoscopy detected 10 cases of intraductal MPT lesions that could not be detected by endoscopic ultrasonography or endoscopic retrograde pancreatography. Five of 10 cases were intraductal multicentric lesions. In 3 of these 5, additional pancreatic resection was performed. For diagnosis of MPT lesions, the sensitivity, specificity, and overall accuracy of intraoperative pancreatoscopy were all 100%; respective values were 43.8%, 100%, and 60.9% for endoscopic retrograde pancreatography and 47%, 100%, and 62.5% for endoscopic ultrasonography. CONCLUSIONS Intraoperative pancreatoscopy is safe and effective in diagnosing the intrapancreatic duct extension and multicentric lesions of MPT. It provides important information for operative strategy and contributes to successful pancreatic surgery.