Evolution of splenomegaly in liver cirrhosis: Simulation using an electronic circuit

Purpose: The evolution of splenomegaly in patients with liver cirrhosis remains largely unknown. In this study, we followed the changes in splenic volume and established the natural course of splenomegaly. We developed an electronic circuit that simulated splenoportal circulation and identified the underlying hemodynamic mechanisms.

Materials and methods: This retrospective observational study included 93 patients with cirrhosis. Splenic volumes were measured in imaging studies at 6-month intervals and normalized by the ratio of each patient's maximum volume during follow-up (%Vmax). An electronic simulation model was constructed using software and realized on a breadboard.

Results: Overall, the %Vmax increased from 0.77 ​± ​0.21 to a maximum of 1.00 ​± ​0.00 (p ​< ​0.001) during a median follow-up of 23 (3-162) months and then decreased to 0.84 ​± ​0.18 (p ​< ​0.001) during the next 9 (3-132) months. No interventional radiology procedure was performed to improve hepatic fibrosis and portal hypertension. The evolution of %Vmax showed single-peaked symmetry. An electronic simulation model showed that the upslope of the evolution curve was dependent on the increased intrahepatic vascular resistance and portal hypertension, whereas the downslope was dependent on the decreased portosystemic shunt (PSS) resistance.

Conclusions: Splenomegaly in cirrhotic patients aggravated over a period of 23 months and then regressed spontaneously to its initial volume. Electronic simulation of splenoportal circulation showed that splenic enlargement was due to the advancement of liver cirrhosis and portal hypertension, whereas its regression was due to the development of a PSS.