Transfemoral inferior vena cava–splenic vein shunt: A proof-of-concept alternative to transjugular intrahepatic portosystemic shunt

BACKGROUNDTransjugular intrahepatic portosystemic shunt (TIPS) is often associated with hepatic encephalopathy (HE) due to the shunting of ammonia-rich blood into the systemic circulation. AIMTo investigate ammonia distribution and develop an experimental transfemoral inferior vena cava-splenic vein shunt (TIVSS) to reduce shunting-related ammonia. METHODS This study combined clinical and experimental research to develop the TIVSS technique.In the clinical part, blood samples were collected from multiple portal venous system (PVS) sites during TIPS in patients to analyze the spatial distribution characteristics of ammonia concentration in cirrhotic patients' PVS.In the experimental part, porcine models of TIPS and TIVSS were used to compare ammonia levels between the two procedures, and to assess the feasibility and safety of the TIVSS procedure. RESULTSIn the clinical study, the highest ammonia levels before shunting were found in the superior mesenteric vein, while the lowest were in the splenic vein, and similar results were validated in animal models.In the TIPS group, systemic ammonia levels significantly increased postoperatively and stayed elevated for 7 days, while the TIVSS group showed stable systemic ammonia levels.TIVSS was successfully performed in a porcine model with a similar operative time to TIPS, with no major complications observed in this experimental setting.4 / 32 CONCLUSION PVS exhibits a significant spatial ammonia gradient.TIVSS shunts low-ammonia splenic vein blood to reduce postoperative hyperammonemia, demonstrating favorable safety and physiological profiles in a porcine model as a proof-of-concept.