The most accurate diagnostic test for Zollinger-Ellison syndrome (ZES) is:
All patients with gastrinoma have an elevated gastrin level, and hypergastrinemia in the presence of elevated basal acid output (BAO) strongly suggests gastrinoma. Patients with gastrinoma usually have a BAO >15 mEq/h or >5 mEq/h if they have had a previous procedure for peptic ulcer. Acid secretory medications should be held for several days before gastrin measurement, because acid suppression may falsely elevate gastrin levels. Causes of hypergastrinemia can be divided into those associated with hyperacidity and those associated with hypoacidity (Fig. below). The diagnosis of ZollingerEllison syndrome (ZES) is confirmed by the secretin stimulation test. An intravenous (IV) bolus of secretin (2 U/kg) is given and gastrin levels are checked before and after injection. An increase in serum gastrin of 200 pg/mL or greater suggests the presence of gastrinoma. Patients with gastrinoma should have serum calcium and parathyroid hormone levels determined to rule out multiple endocrine neoplasia type 1 (MENl) and, if present, parathyroidectomy should be considered before resection of gastrinoma.
Algorithm for diagnosis and management of hypergastrinemia:
B 1 = Billroth I; B 2 = Billroth II; BAO = basal acid output; Bx = biopsy; ECL = enterochromaffin-like; EGO = esophagogastroduodenoscopy; GJ = gastrojejunostomy; H2RA = histamine 2 receptor antagonist; insuff = insufficiency; MEN 1 = multiple endocrine neoplasia type 1; PPI = proton pump inhibitor; R/0 = rule out; SB = small bowel; S/P = status post; TV = truncal vagotomy; TV and A= truncal vagotomy and antrectomy.
Which of the following is the preoperative imaging study of choice for gastrinoma?
CT will detect most lesions >lcm in size and magnetic resonance imaging (MRI) is comparable. Endoscopic ultrasound (EUS) is more sensitive than these other noninvasive imaging tests, but it still misses many of the smaller lesions, and may confuse normal lymph nodes for gastrinomas. Currently, the preoperative imaging study of choice for gastrinoma is somatostatin-receptor scintigraphy (the octreotide scan). When the pretest probability of gastrinoma is high, the sensitivity and specificity of this modality approach 100%. Gastrinoma cells contain type II somatostatin receptors that bind the indium-labeled somatostatin analogue (octreotide) with high affinity, making imaging with a gamma camera possible. Currently, angiographic localization studies are infrequently performed for gastrinoma.
Patients taking nonsteroidal anti-inflammatory drugs (NSAIDs) or aspirin need concomitant acid suppressing medication if which of the following is present?
The overall risk of significant serious adverse gastrointestinal ( GI) events in patients taking nonsteroidal anti-inflammatory drugs (NSAIDs) is more than three times that of controls (Table below). This risk increases to five times in patients older than 60 years. Factors that clearly put patients at increased risk for NSAID-induced GI complications include age >60, prior GI event, high NSAID dose, concurrent steroid intake, and concurrent anticoagulant intake. Alcohol is commonly mentioned as a risk factor for peptic ulcer disease (PUD), but confirmatory data are lacking. High doses of H2 blockers have been shown to be less effective than proton pump inhibitors (PPis) in preventing GI complications in these high risk patients on antiplatelet therapy, but clearly they are better than no acid suppression.
Hospitalization rates for Gl events with and without NSAID use in selected large populations:
aMUCOSA and VIGOR trials included only rheumatoid arthritis patients; CLASS trial included osteoarthritis (73%) and rheumatoid arthritis (27%). blncidence for MUCOSA trial represents doubling of resu lts provided at 6 months (a lthough median follow-up was <6 months). Incidences for VIGOR and CLASS trials represent rates per 100 patient-years, although VIGOR median follow-up was 9 months and CLASS data include only the first 6 months of the study. cIncludes perforations, obstructions, bleedi ng, and uncomplicated ulcers discovered on clinically indicated work-up. dIncl udes perforation, obstruction, bleeding (documented due to ulcer or erosions in MUCOSA and CLASS; major bleeding in VIGOR). e21% of patients in CLASS study were taking low-dose aspirin. Note: All differences between controls and study drugs were significant except clinical upper Gl events in overall CLASS study (P = .09).
The optimal initial management of a patient hospitalized for a bleeding peptic ulcer is:
The management of bleeding peptic ulcer is summarized in the algorithm in Fig. below. All patients admitted to hospital with bleeding peptic ulcer should be adequately resuscitated and started on continuous IV PPI. Seventy-five percent of patients will stop bleeding with these measures alone, but 25% will continue to bleed or will rebleed in hospital. Among the high risk group, endoscopic hemostatic therapy is indicated and usually successful. Only then should surgical intervention be considered, with indications including massive hemorrhage unresponsive to endoscopic control and transfusion requirement of more than four to six units of blood, despite attempts at endoscopic control. Long-term maintenance PPI therapy should be considered in all patients admitted to hospital with ulcer complications.
Algorithm for the treatment of bleeding peptic ulcer:
ASA = acetylsalicylic acid; EGO = esophagogastroduodenoscopy; IV = intravenous; OR = operating room; PPI = proton pump inhibitor; PRBC = unit of packed red blood cells; PT = prothrombin time; PTI = partial thromboplastin time; Rx = treatment.
Which of the following options is the least preferable reconstruction for patients undergoing antrectomy for PUD?
Following antrectomy, GI continuity may be reestablished with a Billroth I gastroduodenostomy or a Billroth II loop gastrojejunostomy. Since antrectomy routinely leaves a 60 to 70% gastric remnant, routine reconstruction as a Roux-en-Y gastrojejunostomy should be avoided. Although the Roux-en-Y operation is an excellent procedure for keeping duodenal contents out of the stomach and esophagus, in the presence of a large gastric remnant, this reconstruction will predispose to marginal ulceration and/or gastric stasis.