Hemodynamic insights into TIPS intervention for portal hypertension management: a comprehensive computational study.

The Transjugular Intrahepatic Portosystemic Shunt (TIPS) is a well-established treatment for complications of portal hypertension in liver cirrhosis, effectively reducing the portal pressure gradient (PPG) and improving transplant-free survival. However, excessive shunting, particularly with larger graft diameters, may increase systemic ammonia levels, predisposing patients to hepatic encephalopathy, and may also precipitate cardiac complications. Computational modelling may therefore eventually serve as a predictive tool for patient selection and pre-procedural planning. In this study, patient-specific TIPS geometries were segmented from CT images and analyzed using computational fluid dynamics with physiologically grounded boundary conditions, before and after TIPS placement. Liver volumetry, hematocrit-dependent blood viscosity, and clinically measured pre-TIPS pressure gradients were incorporated within a coupled 3D-0D multiscale framework. We systematically evaluated the influence of shunt diameter (6-10 mm), puncture location (right, left portal branches and portal bifurcation), angulation, inflow distribution, and outflow partitioning on portal hemodynamics. Results show that the hemodynamic response varies substantially with shunt configuration and patient-specific parameters. Modulating diameter produces a clear trade-off between portal decompression and overshunting. Shunt position, length, and angulation influence PPG only mildly through changes in effective shunt resistance and alter the proportion of TIPS flow originating from the superior mesenteric vein by not more than 10% across configurations. Furthermore, hepatofugal and hepatopetal flow states are mechanistically reproduced, and are governed by the balance between TIPS, intrahepatic portal and sinusoidal-hepatic venous resistances. Overall, this study provides an integrated and physiologically informed framework for understanding and optimizing TIPS configuration in a patient-specific manner.