Superior mesenteric artery syndrome resulting from acute massive gastric dilatation caused by Helicobacter pylori-induced acute antral gastritis

A previously well, slender 14-year-old boy developed right epigastric pain with vomiting. His vomiting gradually changed to bile-stained fluid for 8 h. He was diagnosed with superior mesenteric artery syndrome with acute massive gastric dilatation by contrast-enhanced computed tomography, which also showed markedly thickened prepyloric gastric wall that may have caused gastric outlet stenosis. Acute gastric mucosal lesions of the antrum were confirmed by endoscopic and histological studies. Endoscopic biopsy specimens using rapid urease test and histopathology detected Helicobacter pylori. Serum anti-H. pylori antibody was negative. He did well after conservative treatment. We conclude that an acute form of superior mesenteric artery syndrome resulted from compression of the artery by acute massive gastric dilatation associated with transient gastric outlet stenosis caused by acute antral gastritis, which resulted from the initial H. pylori infection.