Effectiveness of Preoperative Intrahepatic Portal Venous Classification System in Guiding Preoperative Surgical Decisions and Predicting Hypotensive Effects After Meso-rex Bypass for Children With EHPVO.

Background: The categorization of intrahepatic portal venous system (IHPS) patterns using wedged hepatic venous portography (WHVP) has proven to be an effective tool in the preoperative evaluation of Rex recessus and in identifying pediatric patients with extrahepatic portal vein obstruction (EHPVO) who are suitable for meso-Rex bypass (MRB). Despite this classification system being proposed a decade ago, its clinical application remains underutilized.

Methods: A single-center retrospective study of 182 children with EHPVO was conducted between October 2014 and July 2023 when MRB was attempted. Data on demographics, etiology, imaging examinations, procedures, and follow-up were collected for 161 patients included. Two interventional radiologists used deVille's method to classify patients into types A to E based on WHVP imaging, with interobserver agreement analyzed. Associations between IHPS patterns and surgical outcomes following MRB were investigated.

Results: Two radiologists had a high level of agreement on identifying IHPS patterns and suitable patients for MRB. Of the 161 cases, 130 were type A, 10 were type B, 5 were type C, 7 were type D, and 9 were type E. One hundred and forty-five patients with types A, B and C underwent successful MRB, showing feasibility for 90% of patients. Children categorized as types A and B experienced more significant benefits than type C, including intraoperatively decreased portal vein pressure, esophageal/gastric varices relief, decreased portal venous collaterals and a lower rate of bypass occlusion after one year. The surgical outcomes of patients with types A and B were not influenced by the diameter of the Rex recessus as suggested by WHVP.

Conclusions: The majority of pediatric patients with EHPVO in mainland China have opportunities to receive successful MRB. There are potential differences in the etiology of Chinese and Western patients. The IHPS classification system aids in guiding preoperative surgical decisions and predicting hypotensive effects after MRB. Type C patients should be carefully chosen for MRB.