Discovery of a spontaneous portosystemic shunt following portal vein embolization.

INTRODUCTION: Right portal vein embolization (PVE) has become a crucially important option in the minimally-invasive treatment of hepatocellular carcinoma or secondary liver malignancy before partial hepatectomy or trisegmentectomy to reduce perioperative morbidity. The main goal of PVE is to increase the volume of the future liver remnant (FLR), which can provide complete liver metabolic functionality without risk of developing posthepatectomy liver failure, also known as "small for size syndrome." PVE accomplishes this via the redirection of portal venous flow toward the left portal vein circulation resulting in an increased left hepatic lobe volume. CASE REPORT: We present a patient with a noncirrhotic liver and a previously unknown portal venous to systemic venous shunt that became apparent after a right PVE was completed. Left untreated, this shunt would have undoubtedly jeopardized the FLR volume. CONCLUSION: The presence of previously undetected portosystemic shunting is a potential cause for otherwise assumed idiopathic PVE failure, and the goal of this article is to underscore the importance of evaluating for these shunts before PVE.