Preconditioning by portal vein embolization modulates hepatic hemodynamics and improves liver function in pigs with extended hepatectomy

Abstract

Background. Portal vein embolization is performed weeks before extended hepatic resections to increase the future liver remnant and prevent posthepatectomy liver failure. Portal vein embolization performed closer to the operation also could be protective, but worsening of portal hyper-perfusion is a major concern. We determined the hepatic hemodynamic effects of a portal vein embolization performed 24 hours prior to hepatic operation. Methods. An extended (90%) hepatectomy was performed in swine undergoing (portal vein embolization) or not undergoing (control) a portal vein embolization 24 hours earlier (n = 10/group). Blood tests, hepatic and systemic hemodynamics, hepatic function (plasma disappearance rate of indocyanine green), liver histology, and volumetry (computed tomographic scanning) were assessed before and after the hepatectomy. Hepatocyte proliferating cell nuclear antigen expression and hepatic gene expression also were evaluated. Results. Swine in the control and portal vein embolization groups maintained stable systemic hemodynamics and developed similar increases of portal blood flow (302 ± 72% vs 486 ± 92%, P = .13). Portal pressure drastically increased in Controls (from 9.4 ± 1.3 mm Hg to 20.9 ± 1.4 mm Hg, P < .001), while being markedly attenuated in the portal vein embolization group (from 11.4 ± 1.5 mm Hg to 16.1 ± 1.3 mm Hg, P = .061). The procedure also improved the preservation of the hepatic artery blood flow, liver function, and periportal edema. These effects occurred in the absence of hepatocyte proliferation or hepatic growth and were associated with the induction of the vasoprotective gene Klf2. Conclusion. Portal vein embolization preconditioning represents a potential hepato-protective strategy for extended hepatic resections. Further preclinical studies should assess its medium-term effects, including survival. Our study also supports the relevance of hepatic hemodynamics as the main pathogenetic factor of post-hepatectomy liver failure.