Role of Computed tomography in predicting prognosis of Hepatic portal venous gas

Abstract

Background: The aim of this study was to report through 13 cases the particularities of abdominal computed tomography (CT) aspects of hepatic portal venous gas (HPVG) and its correlation with patient prognosis.

Methods: We analyzed abundance of HPVG and its association with pneumatosis intestinalis (PI) in correlation with fatal outcome using chi-square tests.

Results: Etiologies were mesenteric infarction (n=5), sigmoid diverticulitis (n= 1), septic shock (n=1), postoperative peritonitis (n=1), acute pancreatitis (n=1), iatrogenic cause (n=3) and idiopathic after a laparotomy (n=1). The outcome was fatal in for 6 patients. Abundance of HPV was expressed in total number of hepatic segments involved. The involvement of 3 or more segments was a sensitive sign for lethal outcome with high sensitivity (100%) but it was not specific (50%). Negative predictive value of this sign was 100% (p≤0.005). Positive predictive value of PI for death was 100% (p≤0.001).

Discussion: Abundance of HPVG is correlated with prognosis. The presence of PI announces poor outcome Negative predictive value of presence of HPVG in 3 or more segments is interesting. Predicting prognosis with CT can help surgeons to assess the most adequate treatment. Iatrogenic causes are increasingly described after interventional radiology procedures with favorable course.

Conclusion: The first etiology radiologists should look for in front of HPVG involving more than 3 hepatic segments and associated with PI is intestinal necrosis which announces a poor prognosis. This study shows that outside of shock situations, HPVG involving 2 or less hepatic segments without PI predicts a good outcome.

Keywords: Acute mesenteric ischemia; Computed tomography; Diverticulitis; Gas; Portal vein; Surgery.

Fig. 1

72 years-old male with atrial fibrillation, Diffuse abdominal pain, a: pneumoperitoneum (black arrow), HPVG (black bold arrow) b: Superior mesenteric artery occluded (bold white arrow) c and a: pneumatosis intestinalis (white arrows).

Fig. 2

CT after an external biliary drainage in a 69 year-old woman followed for cholangiocarcinoma (case 4).Left portal branches venous gas (a and b:white arrows), Dilated Intrahepatic bile ducts pacified with contrast(b, black arrow).

Fig. 3

unenhanced CT scans showing small quantities of HPVG (case5). No etiology was discussed on CT even after the laparotomy. Idiopathic HPVG was concluded after spontaneous resolution of the abdominal pain.

Fig. 4

axial CT scans: HPVG (bold arrow) complicating a necrotizing pancreatitis (case 8). Heterogeneous enhancing of the liver and the pancreas with multiple fluid effusions (black arrows) and mesenteric vein gas (white arrow).