To investigate clinical characteristics of collateral circulation compensation pathway and evaluate clinical efficacy of meso-rex bypass (Rex shunt) in children with cavernous transformation of portal vein (CTPV).

Clinical data of 36 children with CTPV who underwent Rex shunt in Hunan Children's Hospital from May 2018 to March 2025 were analyzed retrospectively. The informed consents of the guardians of all children were obtained and the local ethical committee approval was received. Among them, 15 patients were male and 21 female, aged from 1.0 to 15.0 years, with a median age of 4.6 years. 33 children were diagnosed with primary CTPV and 3 cases of secondary CTPV. Regarding clinical manifestations, 3 cases had pancytopenia, 14 cases of pancytopenia complicated with splenomegaly, 18 cases of gastrointestinal bleeding, and 1 case without any symptoms. The diagnosis of CTPV was confirmed by preoperative abdominal ultrasound and enhanced CT scan. Preoperative wedged hepatic venous portography (WHVP) was performed to evaluate the development of intra-and extra-hepatic portal veins. Classical and modified Rex shunts were performed by portal vein sheath-free anastomosis and individualized vascular graft selection. Standardized anticoagulation and follow-up management were given after surgery. Children's conditions and surgical efficacy of Rex shunts were observed. Extra-hepatic portal vein pressure before and after Rex shunts was compared by t-test.

36 children successfully underwent Rex shunts, including 28 cases of classic Rex shunts and 8 cases of modified Rex shunts. Postoperative extra-hepatic portal vein pressure was decreased from (30.4±2.6) mmHg (1 mmHg=0.133 kPa) before surgery to (17.4±1.1) mmHg (t=30.66, P<0.001). Two children developed postoperative chylous leakage, which were cured after nutritional support, anti-infection and proper drainage. The remaining children were discharged after recovery. Three-dimensional CT reconstruction showed the patency of the portal veins. The follow-up duration was 5-84 months, with a median follow-up of 26 months. 4 children developed postoperative bypass graft embolization, and 2 of them underwent secondary Rex shunts, using internal jugular vein and inferior mesenteric vein as vascular grafts. The other 2 cases were observed during outpatient follow-up. 3 children were complicated with postoperative bypass graft stenosis, 2 of them received interventional balloon dilatation and 1 underwent stent implantation. In 34 children, the symptoms of portal hypertension were significantly relieved and absent within half a month. In the remaining 2 cases, Plt and WBC were not restored to normal, and no variceal bleeding in the lower esophageal fundus was observed.

Rex shunt can effectively reconstruct portal vein blood flow into the liver in children with CTPV, and significantly reduce extra-hepatic portal hypertension. Portal vein sheath-free anastomosis technique and individualized vascular graft selection determine surgical success, which evidently improve the success rate and patency rate of vascular anastomosis.