Immaturity of Bile Canalicular-Ductule Networks in the Future Liver Remnant While Associating Liver Partition and Portal Vein Occlusion for Staged Hepatectomy (ALPPS).

Abstract

We studied histologic changes of bile canalicular-ductule networks in the future liver remnant (FLR) while associating liver partition and portal vein occlusion for staged hepatectomy (ALPPS), since little is known about regeneration of these networks during the relatively short interval between procedures in ALPPS. Bile canalicular-ductule networks were examined in specimens from eight patients treated with ALPPS and six patients undergoing hepatectomy following portal vein embolization (PVE). Expression of multidrug resistance-1 (MDR1), a membrane transporter in bile canaliculi (BC), was analyzed immunohistochemistcally. Morphologic changes of BC and tight junctions (TJs) adjoining BC were also assessed electron microscopically. Extrapolated kinetic growth of the FLR was greater during ALPPS (17.2±6.8mL/day) than after PVE (6.3±3.4mL/day; p=0.005), and continuity of the MDR1-positive bile canalicular networks was less evident in ALPPS than PVE (p<0.001). Electron microscopically, no significant difference was evident in numbers of BC or BC lumen size between the two groups; however, development of microvilli in BC was poorer in the ALPPS group than in the PVE group (p<0.001). TJ/desmosome complexes were shorter in the ALPPS group (0.69±0.52μm) than in the PVE group (1.09±0.50μm; p<0.001), and leaky TJs were seen more frequently in the ALPPS group (64.9 vs. 23.6%; p=0.001). Regeneration of bile canalicular-ductule networks in the FLR was poorer in ALPPS than PVE, which may be associated with prolonged cholestasis following final hepatectomy in ALPPS.