Continuous or intermittent vascular clamping during hemihepatectomy in pigs: Hyaluronic acid kinetics in the assessment of early microvascular liver damage

Objective: To assess the uptake of hyaluronic acid (HA) as a marker of micr ovascular damage in a model of hemihepatectomy in pigs having continuous or intermittent vascular inflow occlusion. Design: Prospective, animal study. Setting: Laboratory for experimental surgery, University hospital, The Neth erlands. Interventions: Total liver ischaemia was achieved during 90 minutes by cont inuous (n = 5) or intermittent (n = 5) occlusion of the portal vein and hep atic artery followed by 120 minutes of reperfusion. In a second series of p igs (n = 8) a left hemihepatectomy was added to the protocol. Main outcome measures: Uptake of exogenous HA was assessed before ischaemia and after 120 minutes of reperfusion, together with the galactose eliminat ion capacity. Plasma activities of aspartate aminotransferase (AST), alanin e amino transferase, and lactate dehydrogenase were measured and specimens of liver were obtained for histopathological examination. Results: HA uptake was slightly reduced after reperfusion in unresected liv ers compared with uptake before ischaemia. After hemihepatectomy HA uptake after reperfusion was significantly reduced after both continuous and inter mittent occlusion, but more HA was taken up after continuous occlusion (p = 0.02). Release of AST after reperfusion was increased only after hemihepat ectomy. Conclusions: Microvascular damage, as assessed by HA uptake capacity, signi ficantly contributed to normothermic ischaemia and reperfusion injury in po rcine liver. Vascular inflow occlusion during 90 minutes in combination wit h hemihepatectomy resulted in less liver damage when vascular occlusion was continuous rather than intermittent.