Right portal vein-inferior vena cava shunt in portal hypertension: a multicenter case series of a rare spontaneous portosystemic shunt

Spontaneous portosystemic shunts (SPSS) caused by portal hypertension often require to be treated when associated with clinical symptoms in patients. This study aims to report a rare type of spontaneous portosystemic shunt: the Right Portal Vein-Inferior Vena Cava Shunt (RPIVS). This retrospective observational study collected the cirrhosis patients with RPIVS according to the electronic medical record systems between January 2017 to September 2024 from seven medical centers in China. Demographic information, imaging characteristics, laboratory data, treatment, and outcomes were collected. A total of the data of 2165 cirrhosis patients were reviewed and 25 (1.15%) patients (mean age 56.2 ± 11.7 years; 80.0% male) presented RPIVS, with hepatitis B cirrhosis as the dominant etiology (72.0%). Among these patients, 14 (56.0%, 14/25) were hospitalized due to gastrointestinal bleeding, 10 (40.0%, 10/25) were due to the detection of liver tumor, and 1 (4.0%, 1/25) presented with impaired liver function. Three patients developed hepatic encephalopathy, and 3 patients experienced rebleeding. Among the 14 patients admitted for gastrointestinal bleeding, 5 received conservative treatment alone, 6 received endoscopic treatment combined with conservative treatment and/or splenectomy, and 3 underwent TIPS. Among the 10 patients admitted for liver tumor, 7 received liver tumor-related treatment, 1 underwent liver transplantation, 1 received HAIC combined with PTCD and biliary stent implantation, and 1 was awaiting liver transplantation. This study confirms the existence of RPIVS as a rare shunt and speculates on its anatomical basis, which is of great significance for further understanding of portal hypertension and achieving more precise interventions.