Quantitative characterization of superior mesenteric vein blood distribution in the portal venous system using computational fluid dynamics to guide clinical transjugular intrahepatic portosystemic shunt puncture locations

The location of the transjugular intrahepatic portosystemic shunt (TIPS) puncture significantly influences the hemodynamics of the portal system postoperatively, particularly the distribution of blood from the superior mesenteric vein (SMV), which may affect the risk of hepatic encephalopathy (HE) following TIPS. Currently, SMV blood distribution can only be assessed qualitatively in clinical practice, limiting its utility for guiding TIPS surgical planning. In this study, a numerical simulation method based on computational fluid dynamics was used to accurately and noninvasively quantify SMV blood distribution in patients with portal hypertension (PH) before and after TIPS. 45 patients with cirrhotic PH treated with TIPS (14 patients with TIPS in left portal vein while 31 patients with TIPS in right portal vein) at Henan Provincial People's Hospital and West China Hospital (December 2021–July 2024) were selected. Flow and pressure data from clinical measurements served as inlet and outlet boundary conditions, with SMV and splenic vein (SV) blood modeled as liquid phases 1 and 2, respectively. Results indicated significant mixing of SMV and SV blood within the portal vein, with substantial variation between patients and before and after the TIPS procedure. Post-TIPS, the proportion of SMV blood within the stent was significantly higher in the patients with HE compared those without HE (P < 0.001). This study reconfirmed the strong correlation between SMV blood distribution and HE after TIPS, demonstrating that noninvasive quantitative analysis can aid clinicians in selecting optimal TIPS puncture locations, potentially reducing the incidence of postoperative HE.