Portal Venous Gas Following Laparoscopic Rectal Surgery: A Case Report of Internal Herniation without Bowel Necrosis

The presence of free air (pneumatosis) in the main and intrahepatic portal veins generally indicates acute mesenteric ischaemia, often accompanied by bowel necrosis. Internal herniation (IH) is a rare but serious complication of laparoscopic rectal surgery, where the mesenteric window is deliberately left open. IH, followed by mechanical intestinal obstruction, can cause intestinal damage, ischaemia, and necrosis, which may manifest as hepatic portal venous gas (HPVG) on imaging. In cases linked to IH, mesenteric ischaemia often results in a severe and potentially fatal clinical course. Here, despite computerised tomography findings suggestive of advanced ischaemia, a young patient underwent successful surgical intervention for IH. Rapid diagnosis and prompt emergency surgery enabled the reduction of the herniation without bowel resection, preventing progression to irreversible complications. Although leaving mesenteric windows open maintains anastomotic perfusion, this practice may carry a risk of IH in selected patients. Importantly, no bowel resection was needed, illustrating the importance of early detection. Further comprehensive studies are recommended to explore this issue.