Intraoperative methods to stage and localize pancreatic and duodenal tumors

Intraoperative methods to stage and localize tumors have dramatically improved. Advances include less invasive methods to obtain comparable results and precise localization of previously occult tumors. The use of new technology including laparoscopy and ultrasound has provided some of these advances, while improved operative techniques have provided others. Laparoscopy with ultrasound has allowed for improved staging of patients with pancreatic cancer and exclusion of patients who are not resectable for cure. We performed laparoscopy with ultrasound on 50 consecutive patients with adenocarcinoma of the pancreas or liver who appeared to have resectable tumors based on preoperative computed tomography. 22 patients (44%) were found to be unresectable because of tumor nodules on the liver and/or peritoneal surfaces or unsuspected distant nodal or liver metastases. The site of disease making the patient unresectable was confirmed by biopsy in each case. Of the 28 remaining patients in whom laparoscopic ultrasound predicted to be resectable for cure, 26 (93%) had all tumor removed. Thus laparoscopy with ultrasound was the best method to select patients for curative surgery. Intraoperative ultrasound (IOUS) has been a critical method to identify insulinomas that are not palpable. Nonpalpable tumors are most commonly in the pancreatic head. Because the pancreatic head is thick and insulinomas are small, of 9 pancreatic head insulinomas only 3 (33%) were palpable. However, IOUS precisely identified each (100%). Others have recommended blind distal pancreatectomy for individuals with insulinoma in whom no tumor can be identified. However, our data suggest that this procedure is contraindicated as these occult tumors are usually within the pancreatic head. Recent series suggest that previously missed gastrinomas are commonly in the duodenum. IOUS is not able to identify these tumors, but other methods can. Of 27 patients with 31 duodenal gastrinomas, palpation identified 19 (61%). IOUS did not image a single tumor that was not palpable. Endoscopy with duodenal transillumination found an additional 7 tumors (84%), and duodenotomy identified an additional 5 (100%). Thus duodenotomy (opening the duodenum) is indicated in all patients with gastrinoma as duodenal tumors are missed by other means including ultrasound, palpation and transillumination. In conclusion, laparoscopy with ultrasound is useful for selecting patients with pancreatic cancer for curative surgery. Ultrasound is critical for operative identification of insulinomas especially in the pancreatic head, and duodenotomy can identify duodenal wall gastrinomas that are missed by other methods.