Recurrent Hepatic Encephalopathy After Abdominal Surgery in a Non-Cirrhotic Patient: A Case Report

Background and Clinical Significance: Hepatic encephalopathy (HE) is a reversible brain dysfunction typically associated with cirrhosis and portal hypertension. In these patients, portosystemic shunts allow ammonia and other toxins to bypass hepatic metabolism, leading to neurological symptoms. However, HE can also occur in non-cirrhotic patients through congenital shunts or, less commonly, through iatrogenic shunts following abdominal trauma or surgery. This case is clinically significant as it illustrates a rare presentation of recurrent HE caused by a de novo portosystemic shunt following major abdominal surgery in a patient without underlying liver disease. Case Presentation: A 76-year-old male was admitted with confusion, lethargy, and flapping tremors. His medical history included a total pancreatectomy for pancreatic adenocarcinoma six months prior. Laboratory tests revealed hyperammonemia and altered liver enzymes likely related to ongoing chemotherapy, but no signs of hepatic insufficiency or cirrhosis. A review of recent CT imaging identified a new portosystemic shunt between the portal territory and the azygous vein that was absent prior to his pancreatectomy. This iatrogenic shunt likely formed via the re-vascularization of vestigial vessels following surgical de-vascularization. The patient was successfully managed with lactulose and rifaximin. At 3-month follow-up, no further HE episodes had occurred. Conclusions: This case highlights that HE should be considered in patients without cirrhosis presenting with altered mental status and hyperammonemia, especially following abdominal surgery. It underscores the importance of a multidisciplinary approach and meticulous re-evaluation of imaging to identify iatrogenic vascular shunts that may be amenable to medical or interventional management.