Zollinger-Ellison syndrome: prospective assessment of abdominal US in the localization of gastrinomas.

The ability of abdominal ultrasound (US) to help localize gastrinomas was prospectively studied in 79 patients with Zollinger-Ellison syndrome. The results were assessed by means of laparotomy, autopsy, or percutaneous liver biopsy. For hepatic gastrinoma, US had a sensitivity of 63% and a specificity of 100%, with a positive predictive value of 100% and a negative predictive value of 89%. US was slightly less sensitive for detecting gastrinoma in the liver than were computed tomography (CT) (66%) and selective angiography (78%). For detection of extrahepatic gastrinoma, US had a sensitivity of 30%, a specificity of 94%, a positive predictive value of 100%, and a negative predictive value of 25%. US enabled detection of tumor in eight cases not detected with CT and in four not detected with angiography. Specificity for extrahepatic gastrinoma was similar for all three modalities (89%-95%). CT and US were equally effective for the detection of extrahepatic gastrinoma, and angiography was significantly more effective than both US and CT (P less than .01). The authors conclude that US, although of low sensitivity, remains useful as the initial imaging modality in patients with Zollinger-Ellison syndrome.

Detection of duodenal gastrinomas by operative endoscopic transillumination. A prospective study.

The ability of operative endoscopic transillumination of the bowel wall to detect duodenal gastrinoma was evaluated prospectively in 26 patients with the Zollinger-Ellison syndrome. The results were assessed by exploratory laparotomy and compared with the results of other localization techniques. Twelve duodenal gastrinomas were resected from 10 patients. Operative endoscopic transillumination detected 10 of the 12 gastrinomas, a sensitivity of 83%, which was significantly greater (P less than 0.05) than that for either preoperative imaging (25%) or intraoperative ultrasonography and palpation (42%). The sensitivity of operative endoscopic transillumination was a result of the ability to detect focal areas that did not transilluminate on the serosal side of the duodenum, and not the mucosal appearances seen through the endoscope, which were not helpful. Operative endoscopic transillumination detected gastrinomas less than 1 cm in diameter throughout the duodenum. Of the patients in this study, 39% had duodenal gastrinomas, a greater frequency than previously reported. These results indicate that operative endoscopic transillumination is the most sensitive technique yet described for detecting duodenal gastrinomas and should be performed routinely in all patients with the Zollinger-Ellison syndrome who undergo exploratory laparotomy for cure.

Intravenous omeprazole in patients with Zollinger-Ellison syndrome undergoing surgery.

Twenty patients with Zollinger-Ellison syndrome who were undergoing surgery were studied prospectively to assess the efficacy and safety of IV omeprazole. During the preoperative period, in 19 of 20 patients, omeprazole 60 mg administered as an IV bolus every 12 hours inhibited acid output to less than 5 mEq/h measured in the last hour before the next dose of drug. In one patient, acid output was 25 mEq/h 12 hours after omeprazole, 60 mg, and increasing the dose to 100 mg every 12 hours reduced acid output to less than 5 mEq/h. During the operative and postoperative periods, IV omeprazole controlled gastric acid hypersecretion in all patients for up to 15 days. During this time, all patients received the dose determined preoperatively. No patient developed any clinical, hematological, or biochemical toxicity that could be attributed to omeprazole therapy during the preoperative or postoperative period. The present study demonstrates that omeprazole administered by IV bolus is safe and effective for controlling gastric acid hypersecretion. In contrast to IV histamine H2-receptor antagonists, IV omeprazole has the advantages of not requiring continuous infusion or postoperative dose adjustments. Intravenous omeprazole will become the drug of choice in patients with Zollinger-Ellison syndrome undergoing surgery.

Gastrinomas: localization by means of selective intraarterial injection of secretin.

Small doses (30 U) of secretin were injected directly into the splenic, gastroduodenal, hepatic, and superior mesenteric arteries of 13 patients with Zollinger-Ellison syndrome who were undergoing angiography to localize gastrin-secreting tumors of the islet cells. Blood samples from the right hepatic vein and a peripheral vein were drawn before and 30, 60, 120, and 210 seconds after each intraarterial secretin (IAS) injection. A 50% rise in gastrin level in the 30-second sample from the hepatic vein localized the gastrinoma to the head, body, or tail of the pancreas, depending on the artery into which secretion was injected. IAS results were positive in seven of 13 patients (54%); selective angiography was positive in five of 13 (38%); and the combined study, selective angiography with IAS injection, was positive in 10 of 13 (77%). Portal venous sampling was positive in six of 13 (46%). Selective IAS injection, combined with angiography, is the most sensitive study for localizing gastrinomas and avoids percutaneous transhepatic catheterization for portal venous sampling.

Enhancement of 1,2-dimethylhydrazine-induced large bowel tumorigenesis in Balb/c mice by corn, soybean, and wheat brans.

This study was designed to determine the effects of four well-characterized dietary brans on large bowel tumorigenesis induced in mice with 1,2-dimethylhydrazine (DMH). Eight-week-old barrier-derived male Balb/c mice were fed a semisynthetic diet with 20% bran added (either corn, soybean, soft winter wheat, or hard spring wheat) or a no-fiber-added control diet. Half of each group was given DMH (20 mg/kg body weight/week, subcutaneously for 10 weeks) beginning at 11 weeks of age. Surviving mice were killed 40 weeks after the first DMH injection. Tumors were not found in mice not subjected to DMH. In DMH-treated mice, tumors were found almost exclusively in the distal colon. Tumor incidences were as follows: controls, 11%; soybean group, 44%; soft winter wheat group, 48%; hard spring wheat group, 58%; and corn group, 72%. Tumors per tumor-bearing mouse ranged from 1.4 to 1.6, except in the corn group, which had 2.1. A positive correlation was found between percentage of neutral detergent fiber in the brans and tumor incidences but not between the individual components of cellulose, hemicellulose, or lignin. The enhancement of DMH-induced large bowel tumorigenesis by all four bran types may reflect a species and/or mouse strain effect that is bran-source related. These data emphasize the importance of using well-defined bran in all "fiber" studies.