Liver inflow adaptation after major hepatectomies is explained by the hepatic compliance

Abstract

Aims: Small-for-size syndrome is one of the main limiting factors for the regeneration of the remnant liver after extended hepatectomy. It is related to an imbalance between excessive portal venous inflow and insufficient liver volume. Increase in portal vein flow (PVF) or in hepatic veinous pressure gradient (HVPG) are predictors of SFSS although no correlation between these values has been established. We conducted an experimental study in swine to assess the adaptation of the liver inflow after major and subtotal hepatectomies. Methods: 14 pigs underwent systemic and splanchnic hemodynamics recording (PVF, HVPG , HAF : hepatic artery flow) before and after 70% hepatectomy (H70 : n = 7) or 90% hepatectomy (H90 : n = 7). To evaluate the liver compliance, we used Ohm's law formula : PVR = HVPG/PVF. Results: PVF increased after H70 (273 vs 123 ml/min/100g p = 0.016) and H90 (543 vs 124 ml/min/100g p = 0.031). HVPG significantly increased only after H90 (10 vs 3,7mmHg p = 0.016). PVR was two times lower after H70 whereas it increased after H90. (fig1) Conclusions: We assume that the difference observed in HVPG and PVR after 70% and 90% hepatectomy was related to the compliance capacity of the non-cirrhotic liver, such as the increase in PVF after 90% hepatectomy overtook the hepatic compliance, resulting in an increase in both hepatic resistance and HVPG. It may explain the lack of correlation between HVPG and PVF reported in previous studies.