Value of preoperative computed tomography for meso-Rex bypass in children with extrahepatic portal vein obstruction

Huiying Wu,Xiwen Chen,Lianwei Lu,Tao Liu,Hongsheng Liu,Binbin Zhang,Ning Zhou,Zhe Wen

doi:10.1186/s13244-021-01057-8

Huiying Wu, Xiwen Chen + Show 6 more

Open Access

https://doi.org/10.1186/s13244-021-01057-8

Copy DOI

Abstract

BackgroundExtrahepatic portal vein obstruction (EHPVO) is the most important cause of hematemesis in children. Intrahepatic left portal vein and superior mesenteric vein anastomosis, also known as meso-Rex bypass (MRB), is becoming the gold standard treatment for EHPVO. We analyzed the value of preoperative computed tomography (CT) in determining whether MRB is feasible in children with EHPVO.ResultsWe retrieved data on 76 children with EHPVO (50 male, 26 female; median age, 5.9 years) who underwent MRB (n = 68) or the Warren procedure (n = 8) from 2013 to 2019 and retrospectively analyzed their clinical and CT characteristics. The Rex recess was categorized into four subtypes (types 1–4) depending on its diameter in CT images. Of all 76 children, 7.9% had a history of umbilical catheterization and 1.3% had leukemia. Sixteen patients (20 lesions) had associated malformations. A total of 72.4% of Rex recesses could be measured by CT, and their mean diameter was 3.5 ± 1.8 mm (range 0.6–10.5 mm). A type 1, 2, 3, and 4 Rex recess was present in 9.2%, 53.9%, 11.8%, and 25.0% of patients, respectively. MRB could be performed in patients with types 1, 2, and 3, but those with type 4 required further evaluation. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of CT were 100%, 83.8%, 42.1%, 100%, and 85.5%, respectively.ConclusionsAmong the four types of Rex recesses on CT angiography, types 1–3 allow for the performance of MRB.

Highlights

Extrahepatic portal vein obstruction (EHPVO) is the most important cause of hematemesis in children
The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of preoperative computed tomography (CT) for meso-Rex bypass (MRB) were 100%, 83.8%, 42.1%, 100%, and 85.5%, respectively
It is the space between hepatic segments III and IV, where the intrahepatic left PV (LPV) is conveniently placed for mesentericoportal anastomosis to restore hepatopetal flow

Summary

Introduction

Extrahepatic portal vein obstruction (EHPVO) is the most important cause of hematemesis in children. Intrahepatic left portal vein and superior mesenteric vein anastomosis, known as meso-Rex bypass (MRB), is becoming the gold standard treatment for EHPVO. Extrahepatic portal vein obstruction (EHPVO) is defined as thrombosis of the extrahepatic portal vein (PV) with or without extension to the intrahepatic PVs [1] It is the cause of portal hypertension in 70% of pediatric patients and the most common cause of upper gastrointestinal bleeding in children [2, 3]. Meso-Rex bypass (MRB), known as the Rex shunt (Fig. 1a), is the definitive treatment for EHPVO [6] This procedure restores physiological portal liver reperfusion via a venous autograft connection from the superior mesenteric vein (SMV) to the intrahepatic LPV. MRB is the gold standard treatment in children with favorable anatomy

Objectives

Methods

Results

Conclusion