Measurement of spleen size and its relation to hypersplenism and portal hemodynamics in portal hypertension due to hepatic cirrhosis

Aims: Splenomegaly is common in portal hypertension due to hepatic cirrhosis, but there are little data comparing different methods of spleen measurement. We have compared ultrasound with radionuclide imaging in measuring splenomegaly. The relation of splenomegaly to hypersplenism and portal hemodynamic factors was also studied. Results: Ultrasound and radionuclide measures of spleen volume gave comparable results (r = 0.95, p < 0.0001). Phagocytic activity of the spleen measured by radionuclide uptake increased as the volume of the spleen increased (r = 0.46, p < 0.03) but was not related to diminishing liver phagocytic activity. Spleen volume was correlated negatively with leukocyte counts (r = 0.43, p < 0.05) but not with hemoglobin or platelet counts. Spleen radionuclide uptake was negatively correlated with hemoglobin (r = 0.48, p < 0.04) and leukocyte counts (r = 0.46, p < 0.04) but not with platelet counts. Spleen volume was related to portal vein cross-sectional area (r = 0.91, p < 0.0001) and portal vein blood flow volume (r = 0.57, p < 0.008) but not to portal vein blood flow velocity, portal pressure gradient, or azygos blood flow. Conclusions: Spleen size measured by ultrasonography and radionuclide studies gives comparable results. Spleen phagocytic activity in cirrhosis increases as the spleen enlarges but not in relation to decreased hepatic phagocytic activity. Spleen phagocytic activity probably contributes to anemia and leukopenia in the splenomegaly of cirrhosis, but other factors must contribute to thrombocytopenia. Portal hemodynamics are probably important in the splenomegaly, but the interrelation is complex.