A lumped parameter model of liver resections for improving surgical outcomes

The liver serves multiple critical functions related to processing and filtering blood which are vital to maintaining homeostasis. This includes extracting and storing nutrients, removing waste products and toxins, and processing alcohol and medications. Numerous diseases, such as cancer and hepatitis, may necessitate liver resection (i.e., surgery in which a portion of the liver is removed). However, the vascular structure of the liver often leads to challenging surgical decisions, especially related to ligation of the hepatic vein which forms the outflow route from the liver. We will present a lumped parameter model of blood flow through the entire liver, resolved down to the length scale of the lobules (functional units of the liver that are about 1 mm in diameter). Our model is parameterized based on clinical measurements, relies on only a single free parameter, and accurately captures established blood perfusion characteristics. We impose variable, realistic liver resections to our model and quantify the associated changes in volume flow rate, average blood velocity, and wall shear stress which we compare to the intact liver. We will highlight novel factors affecting liver perfusion and present predictions of surgical outcomes. Our numerical model can be adapted to patient-specific anatomy and runs on a laptop in minutes, constituting an appreciable step toward a novel computational tool for assisting surgical decisions in liver resection.