Occurrence of portal venous gas following routine endoscopy: a case report

Portal venous gas (PVG) is commonly associated with severe gastrointestinal disease, whereas benign causes related to endoscopic procedures are uncommon. We report an unusual mechanism of PVG occurring in the setting of chronic gastric outlet obstruction after carbon dioxide (CO₂)-insufflated upper gastrointestinal endoscopy.

A 25-year-old Asian woman presented with recurrent vomiting. She had undergone surgery for duodenal perforation six months earlier and was subsequently lost to follow-up. Her symptoms recently worsened, with significant abdominal distension and vomiting for 3 weeks. A computed tomography (CT) revealed marked gastric dilatation and fibrotic duodenal bulb stenosis. After gastric decompression, CO₂-insufflated gastroscopy was performed while she remained conscious. Severe gastric distension, retained contents, and limited procedural tolerance and cooperation limited visualization, and an ultrathin gastroscope could not pass <1 mm stenosis. The procedure was terminated without any immediate complications. Later that night, she developed abdominal pain. CT demonstrated extensive PVG and submucosal gastric wall air, with normal inflammatory markers and no signs of perforation. Conservative treatment with continued decompression and acid suppression led to rapid clinical improvement, and repeat CT two days later showed complete resolution of PVG. Endoscopy used standard low-flow CO₂ insufflation, total procedure duration was approximately 20 min, and intermittent suctioning was performed for content removal.

In the setting of chronic gastric outlet obstruction and prolonged gastric distension, impaired mucosal integrity together with increased intragastric pressure may predispose to abnormal CO₂ migration into the portal venous system during endoscopy. Possible partial-thickness or submucosal injury during manipulation may further facilitate portal venous gas formation. Recognition of etiologies of PVG that do not require surgery is essential, as many stable patients can be managed conservatively, preventing unnecessary operative intervention.