The Adaptive Response of the Reticuloendothelial System to Major Liver Resection in Humans

Abstract

To evaluate the contribution of the liver to total circulatory reticuloendothelial system (RES) phagocytosis capacity in patients undergoing liver resection and to compare it with values in end-stage chronic liver disease. The mechanism whereby major liver resection is associated with a high incidence of infection is unknown. Significant impairment of RES phagocytosis has been described in liver failure, rendering such patients susceptible to infection; and we hypothesized that similar impairment might occur following major liver resection. A prospective study was conducted in which Tc-albumin microspheres blood clearance served as a parameter for RES phagocytosis and was studied together with indocyanine green blood clearance, actual liver volume measured by three-dimensional image analysis, and a clinical score of hepatic dysfunction in 17 patients undergoing liver resection and in 8 patients with end-stage chronic liver disease assessed for liver transplantation. When expressed relative to volume unit of residual liver, microspheres clearance increased significantly in the immediate postoperative period (day 1) following major (0.009% versus 0.022% min(-1) mL(-1), P < 0.001), but not minor liver resection. In contrast, the absolute rate of microsphere clearance decreased following major resection (15% min(-1) versus 10% min(-1), P < 0.001) and was comparable with the rate observed in end-stage chronic liver disease (9% min(-1)). This decrease in circulatory microspheres clearance after resection paralleled a decrease in indocyanine green clearance (R2 = 0.511, P = 0.006), and there was a trend for those with moderate liver dysfunction to have lower microspheres clearance rates (P = 0.068). Preservation of a minimum volume of functioning liver is a prerequisite for adequate RES phagocytosis capacity, and failure of this system may predispose patients undergoing major liver resection to infection as observed in clinical studies.