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

Area of Science:

• Hepatology
• Pediatric Gastroenterology
• Cardiopulmonary Medicine

Background:

• Intrapulmonary vascular shunting (IPVS) is linked to poor outcomes in pediatric liver transplantation (LT).
• Current guidelines for screening IPVS in pediatric LT are lacking.
• This study investigates IPVS prevalence and impact in pediatric LT recipients.

Purpose of the Study:

• To evaluate intrapulmonary vascular shunting (IPVS) before and after pediatric liver transplantation (LT).
• To assess the relationship between IPVS severity and post-transplant outcomes.
• To determine if LT is feasible in children with mild to moderate IPVS.

Main Methods:

• Retrospective review of 370 pediatric LT cases (2005-2015).
• Included children with cirrhosis and suspected IPVS, excluding cardiac/pulmonary conditions.
• Utilized 99mTechnetium labelled macroaggregated albumin (99mTcMAA) scans to grade IPVS severity via shunt ratios.

Main Results:

• Twenty-four children met inclusion criteria; all had mild to moderate IPVS.
• Mean shunt ratio decreased post-LT (20.69% to 15.1%, P=.06).
• No significant difference in mortality, PVT, biliary strictures, or graft loss compared to controls. Hepatopulmonary syndrome (HPS) observed in 2/24 children.

Conclusions:

• Hepatopulmonary syndrome (HPS) is less common with mild to moderate IPVS.
• Pediatric liver transplantation (LT) can yield comparable results even with mild to moderate intrapulmonary vascular shunting (IPVS).
• Further research may inform screening guidelines for IPVS in pediatric LT.