Rapid disappearance of hepatic portal venous gas despite progressive colonic ischemic necrosis: a case report

Abstract Background Hepatic portal venous gas (HPVG) is an uncommon radiologic sign that may occur in conditions ranging from benign gastrointestinal disorders to bowel ischemia and necrosis. Its prognostic significance depends on the underlying etiology and associated clinical context. Apparent radiologic improvement of HPVG may therefore be misleading if interpreted in isolation. Case presentation A 91-year-old man presented with diarrhea and mild, non-localized upper abdominal discomfort. At the first presentation, he was alert and afebrile, and physical examination showed a soft, non-tender abdomen without peritoneal signs. His initial laboratory findings were unremarkable. Given the overall diarrhea-predominant and apparently mild presentation, acute gastroenteritis was initially considered, and no abdominal imaging was obtained. Seven hours later, he returned with worsening abdominal pain and upper abdominal tenderness. Because the presentation remained relatively non-specific and intestinal ischemia had not yet been established as the leading diagnosis, non-contrast computed tomography (CT) was obtained as a rapid initial screening examination. It demonstrated HPVG predominantly in the left hepatic lobe and mild transverse colonic wall thickening. Intravenous fluids and empirical antibiotics were administered, repeated clinical reassessment was performed, and contrast-enhanced CT was subsequently obtained to evaluate bowel viability, mural enhancement, peritoneal changes, and the mesenteric vasculature. Three hours after first radiologic detection, HPVG was no longer visible; however, the patient developed fever, tachycardia, mildly altered mental status, increased SIRS and qSOFA scores, rising inflammatory markers, marked mural hypoenhancement of the transverse colon, and newly developed intraperitoneal fluid. Emergency laparoscopic exploration revealed transverse colonic ischemic necrosis. Laparoscopic transverse colectomy with colostomy was performed, and histopathological examination confirmed acute ischemic necrosis. The patient recovered and underwent successful stoma reversal 6 months later. Conclusions Rapid radiologic disappearance of HPVG should not be interpreted as clinical improvement in isolation. In suspected intestinal ischemia, management should be guided by integrated clinical, physiological, laboratory, and CT reassessment, particularly bowel-wall enhancement and peritoneal findings. In very elderly patients, atypical symptoms and subtle early signs warrant heightened vigilance.