[Hepatic encephalopathy related to post-radiotherapy stenosis of the common femoral vein].

INTRODUCTION

Hepatic encephalopathy is a neuropsychologic disorder due to hyperammonaemia, related to liver failure and/or portosystemic shunts for instance. We herein describe the case of a 74-year-old woman who developed hepatic encephalopathy in the context of portal hypertension secondary to chronic stenosis of the left common femoral vein.

CASE REPORT: A 74-year-old woman presented with confusion and major hyperammonemia (>100μmol/L). She had a past medical history of angioma of the left leg treated with radiotherapy. Post radiotherapy stenosis of the left common femoral vein occurred, then bypass paths leading to large pelvic varicose veins draining into the inferior mesenteric vein. There was no evidence for liver failure and common causes of confusion were excluded. The liver biopsy was refused by the patient. In the absence of another etiology, the retained diagnosis was an hepatic encephalopathy secondary to portal hypertension, related to inferior mesenteric vein hyper flow draining into the splenic vein, then into the portal vein. Treatment by lactulose and rifaximine allowed clinical improvement and hyperammonemia reduction.

CONCLUSION

An hepatic encephalopathy may occur without any evidence of hepatopathy, in the context of venous malformations responsible for portal venous hyper flow, as illustrated by this unusual case report.