Antral Web Causing Gastric Outlet Obstruction: Endoscopic Diagnosis and Management Options

Abstract

Purpose: Gastric antral web, or antral diaphragm, is a rare cause of gastric outlet obstruction. Management includes surgery and endoscopic incision of the web. We present two cases to increase clinical awareness of this entity. Case 1: An 80-year-old female with a history of hypertension, breast, and lung cancer presented with dysphagia, nausea and vomiting, increased reflux and abdominal fullness. Upper endoscopy showed distal gastric obstruction presumed to be pyloric stenosis. Despite dilation, symptoms returned within weeks. CT showed no evidence of external compression at the pylorus. Repeat endoscopy revealed retained food and an obstructing antral web. Sequential balloon dilation allowed the 9.8 mm endoscope to be advanced without resistance. The pylorus, identified downstream was patent and the duodenum was normal. Given partial return of symptoms within two weeks, endoscopy was repeated and the antral web was incised with a needle knife. Repeat endoscopy for recurrent nausea week later demonstrated an open web. Case 2: A 72-year-old with a history of CAD, diabetes, and gout presents with recurrent vomiting and early satiety. He has a ten-year history of intermittent food regurgitation with weight loss from 220 pounds to 130 pounds. He had an upper GI series, which showed a narrowing at the antrum. Prior outside upper endoscopy and biopsy of “narrowing” was complicated with UGI bleeding. Repeat upper endoscopy revealed an obstructing antral web. A 6-mm endoscope was passed through the web without resistance. Sequential balloon dilation over a guidewire from 8 to 15 mm was performed, and allowed a 9-mm scope to pass through the web easily. The prepyloric antrum and pylorus appeared normal. Patient continues to do well three months post procedure. He is tolerating a regular diet without difficulty and has gained five pounds. Antral web may be congenital or acquired and are a rare cause for gastric outlet obstruction. Gastric outlet obstruction is associated with an opening size less than 1 cm. The theory asserts that peptic ulcers cause circumferential scarring and web formation; the likely etiology in our patients. The congenital webs are presumed to be the result of focal tissue ischemia. Diagnosis is usually made via UGI or endoscopy. On UGI, a ‘double bulb' sign can be seen. On endoscopy, antral webs should be distinguished from the pylorus by the presence of the real pylorus downstream. In the symptomatic patient, endoscopic management should be attempted first. Balloon dilation or endoscopic incision appear to be safe. Although rare, clinicians must be cognizant of antral web as a possible etiology for gastric outlet obstruction.