Experimental and clinical studies on liver regeneration following transcatheter portal embolization.

BACKGROUND/AIMS: We studied compensatory hypertrophy following transcatheter portal embolization experimentally in dogs and clinically under the condition of cholestasis. METHODOLOGY: Experimental study: Sixteen dogs were used for this study. Transcatheter portal embolization was performed in the left lobes (70% of the total liver) using Gelfoam powder in dogs with 2-week obstructive jaundice. Liver weight, liver blood flow and the intracellular adenosine triphospate content of isolated hepatocytes were measured after transcatheter portal embolization. Clinical Study: transcatheter portal embolization of the right portal branch was performed in 13 patients with cancer of the biliary tract and 3 patients with hepatocellular carcinoma before (extended) right lobectomy, using Gelfoam powder and thrombin. Six patients who had a total bilirubin level >5mg/dLunderwent a percutaneous transhepatic biliary drainage before transcatheter portal embolization. Liver function tests, a volumetric study with computed tomography and immunohistochemical staining for profilerating cell nuclear antigen and apoptosis in the resected livers were performed. RESULTS: Experimental study: The weight ratio of the non-embolized lobes to the total liver, 2 weeks after transcatheter portal embolization in the dogs with jaundice, was significantly lower than that of the normal dogs with transcatheter portal embolization (40.5±4.5% vs. 47.6±3.2%), but significantly larger than that of the dogs without transcatheter portal embolization. The cellular adenosine triphospate content and tissue blood flow in the embolized lobes were significantly lower than those in the nonembolized lobes in the normal and cholestatic livers. Clinical study: The postoperative course in all patients was uneventful, with no serious complication or liver dysfunction. Extended right lobectomy with caudate lobectomy was equivalent to 65% before transcatheter portal embolization and to 56% after, transcatheter portal embolization owing to compensatory hypertrophy of the left lobe. However, there was no significant difference in liver volume in the patients with or without obstructive jaundice. Apoptosis was observed in the embolized lobe. CONCLUSIONS: Preoperative transcatheter portal embolization with percutaneous transhepatic biliary drainage for the purpose of liver regeneration would be useful for treating extended hepatectomy with obstructive jaundice.