operative scheme for exploration, localization, and removal of gastrinoma
If no tumor is obvious on preoperative CT scan, and other preoperative localization studies have failed, exploration begins with exposure of the anterior surface of the pancreas by mobilization of the transverse colon. A Kocher maneuver is then performed to mobilize the duodenum, allowing complete bimanual palpation of the pancreas. Intraoperative ultrasound is concentrated in the gastrinoma triangle. Biopsy of lymph nodes should be performed because, occasionally, the gastrinoma is localized to a solitary node. If ultrasound of the pancreas does not reveal the tumor, duodenal gastrinoma should be suspected. A pyloroplasty incision is made, and the duodenal wall is visually inspected and manually palpated. An alternative method of localizing duodenal gastrinomas is to transilluminate the wall with intraoperative endoscopy. Gastrinomas in the duodenal wall or pancreas may be enucleated, but solitary lesions in the pancreatic tail are often treated by distal pancreatectomy.
If no lesion is found or if the disease is found to be multicentric or metastatic, an ulcer operation may be performed as palliation. This procedure often consists of a truncal vagotomy and pyloroplasty. Alternatively, the patient may be maintained on a PPI. In rare cases, a total gastrectomy may be performed for control of acid production in patients who are refractory to medical therapy or unable to tolerate the side effects of the medication.