Air in Stomach Wall-Gastric Emphysema versus Emphysematous Gastritis-Differences and Overlap

Abstract

Introduction: Pneumogastrium, pneumatosis intestinalis (PI) (gastric), gastric emphysema (GE) and emphysematous gastritis (EG) are all terms used to describe air in the wall of the stomach. Its meaning is based on history, exam and radiological pattern of the air. Air outside the lumen of the gut is a rare phenomenon especially so in the foregut. While PI involving the large bowel may be idiopathic in the elderly, gastric involvement is usually an ominous sign. Mechanisms include: mechanical, where in air is thought to cross the mucosal barrier via direct injury to the mucosa like an ulceration or caustic injury; the bacterial model with transgression of gas forming organisms from the gut into the wall with mucosal edema and lastly pneumatosis. Visceral infarct secondary to arterial thrombosis would also be a cause for pneumatosis. Case 1: 21-year-old type 1 diabetic was admitted for DKA which subsequently resolved but patient continued to have feculent emesis. Abdominal exam showed absent bowel sounds. Emergent imaging showed linear lucency along the greater curvature of the stomach. Case 2: 55-year-old with stage 4 adenocarcinoma of the lung was admitted with severe abdominal pain and intractable nausea and vomiting. Exam was significant only for epigastric fullness without tenderness or guarding. Repeat CT scan on day 3 showed air in the gastric wall. Discussion: GE is considered to be secondary to relatively benign conditions, like increased intragastric pressure secondary to gastric outlet obstruction from any cause and usually responds very well to conservative management. It is often described radiographically as linear or “streaky” lucency along the stomach wall. Arterial thrombi can also cause gastric emphysema as was found to be in case 1. EG, also described as phlegmonous gastritis, is considered to be infectious with commonest organisms being Enterococci. Radiographic features include “bubble” like mottled irregular lucencies in the stomach wall. Surgical consult is warranted with immediate nasogastric decompression and initiation of broad spectrum antibiotic therapy. Vomiting seems to be the predominant feature in either condition with peritoneal signs being present commonly in the latter. In case 2, a diagnosis of EG was made based on radiological appearance. It seems that these two entities may just be at the two ends of a spectrum with significant clinical and radiographic overlap. Surgical consult is strongly recommended in all cases with antibiotics use at least in the initial stages. Nasogastric decompression and bowel rest are imperative.