Mild to Moderate Intrapulmonary Shunting in Pediatric Liver Transplantation: Is Screening Necessary?

Abstract

BackgroundDespite reported associations between intrapulmonary vascular shunting (IPVS) and morbidity and mortality in pediatric liver transplantation (LT), there are no guidelines for screening. ObjectiveTo investigate IPVS before and after pediatric LT. MethodsRetrospective records review of all pediatric LT (n = 370) from 2005 to 2015 at a single institute in Japan. All children with cirrhosis and clinical suspicion of IPVS without cardiac or pulmonary conditions were included. 99mTechnetium labelled macroaggregated albumin (99mTcMAA) scans were performed before and after LT. The severity of IPVS was graded using shunt ratios. ResultsTwenty-four children fulfilled inclusion criteria and underwent Tc99MAA scans. All revealed mild (<20%) to moderate (20%-40%) grades of IPVS. Following LT, the mean shunt ratio regressed from 20.69 ± 6.26% to 15.1 ± 3.4% (P = .06). The median (range) follow-up was 17 (4–85) months. Mortality was zero. The incidence of portal vein thrombosis (4.2%) biliary strictures (12.5%) and graft loss (4.1%) in the study group was not statistically significant compared to the remainder of the 370 transplants (3.2%, 9.4% and 3%, respectively). Sub-group analysis revealed hepatopulmonary syndrome (HPS) in 2 out of 24 children. The mean shunt ratios before and after LT were 39.2 ± 0.77% and 16.2 ± 8.5%, respectively (P = .08). There was 1 complication (intra-abdominal abscess). ConclusionsHPS is less likely in mild to moderate IPVS. LT may achieve comparable results when performed in the presence of mild to moderate IPVS.