Uneven acute non-alcoholic fatty change of the liver after percutaneous transhepatic portal vein embolization in a patient with hilar cholangiocarcinoma – a case report

BACKGROUND Portal vein embolization is essential for patients with biliary cancer who undergo extended hepatectomy to induce hypertrophy of the future remnant liver. Over 830 patients have undergone the portal vein embolization at our institution since 1990. Non-alcoholic fatty liver disease is an entity of hepatic disease characterized by fat deposition in hepatocytes. It has a higher prevalence among persons with morbid obesity, type 2 diabetes, and hyperlipidemia. Neither the mechanism of hepatic hypertrophy after portal vein embolization nor the pathophysiology of non-alcoholic fatty liver disease has been fully elucidated. Some researchers integrated the evident insults leading to progression of fatty liver disease into the multiple-hit hypothesis. Among these recognized insults, the change of hemodynamic status of the liver was never mentioned. CASE PRESENTATION We present the case of a woman with perihilar cholangiocarcinoma who received endoscopic biliary drainage and presented to our institute for surgical consultation. A left trisectionectomy with caudate lobectomy and extrahepatic bile duct resection was indicated for curative treatment. To safely undergo left trisectionectomy, she underwent selective portal vein embolization of the liver, in which uneven acute fatty change subsequently developed. The undrained left medial sector of the liver with dilated biliary tracts was spared the fatty change. The patient underwent planned surgery without any major complications 6 weeks after the event and has since resumed a normal life. The discrepancies in fatty deposition in the different sectors of the liver were confirmed by pathologic interpretations. CONCLUSION This is the first report of acute fatty change of the liver after portal vein embolization. The sparing of the undrained medial sector is unique and extraordinary. The images and pathologic interpretations presented in this report may inspire further research on how the change of hepatic total inflow after portal vein embolization can be one of the insults leading to non-alcoholic fatty liver disease/ change.