Enlarged caliber of bypass vein after Rex shunt

Abstract

Objective The patency of bypass vein after Rex shunt is an important prognostic predicator. This study was intended to explore the phenomenon of enlarged caliber of bypass vein after Rex shunt and assess its prognostic effectiveness. Methods From October 2008 to October 2016, 114 children of upper gastrointestinal bleeding were diagnosed as extra-hepatic portal venous obstruction (EHPVO) by abdominal ultrasound and computed tomography (CT). There were 67 boys and 47 girls with an age range of 0.8-17.5 years. Portal cavernoma-portal bypass with an interposition of grafted portal vessels (PP group, n=29), gastroportal shunt (GP group, n=54) and other Rex shunts (gastroepiploic, right gastric or splenic vein bypass) (OB group, n=29) were performed. During postoperative follow-ups, abdominal ultrasound, CT, upper gastrointestinal imaging and laboratory tests (blood routine, blood chemistry and coagulation function) were conducted. And the patency and caliber of bypass vein were assessed with ultrasound and CT. Results The median follow-up period was 2.8 (0.5-8.6) years. The calibers of bypass veins expanded on ultrasound and CT in 40 children at 6 months. Enlarged caliber of bypass vein gradually occurred at 1 month and continued until 24 months. The post-operative incidences of re-bleeding and esophageal varices were significantly lower in children with enlarged bypass vein than those without (P<0.05). No significant difference existed in the incidence of postoperative enlargement of bypass vein among PP, GP and OB groups (P=0.660); No significant difference existed in operative age between children with enlarged bypass vein and those without (P=0.704); No significant difference existed in the incidence of postoperative enlargement of bypass vein between genders (P=0.648). The intra-operative diameter of bypass vein was lower in children with enlarged bypass vein than those without (P=0.005). Pre- and post-operative portal pressure in children with enlarged bypass vein were not significantly different with those without (P=0.161, P=0.313). Post-operative portal pressure significantly decreased in children with enlarged bypass vein than those without (P=0.017). Conclusions With a favorable outcome, enlarged caliber of bypass vein after Rex shunt is correlated postoperatively with lower portal pressure and elevated hepatopetal blood flow. Key words: Extra-hepatic portal venous obstruction; Rex shunt; Prognosis; Child