Decreasing Hemorrhage Risk in Children With Alagille Syndrome

The goal of this interventional study is to test a hemostasis screening protocol and cardiac peri-procedural and post-operative hemostasis pathway to improving bleeding complications and improve patient survival for children with Alagille syndrome and complex cardiac conditions. The main questions it aims to answer are: * Are children with Alagille syndrome with cardiac anomalies more likely to have acquired von Willebrand syndrome (a condition that causes increased bleeding) * Does implementation of a novel screening protocol to detect pre-operative bleeding conditions decrease intra-operative and/or post-operative bleeding complications and mortality risk? * Does implementation of a novel screening protocol to detect and treat bleeding conditions cause thrombotic complications? Participants will undergo additional hematology and bleeding disorder screening prior to cardiac surgery. They will additionally undergo a detailed family screening for a history of bleeding by a genetic counselor. Researchers will compare these findings with children who have similar complex cardiac conditions requiring surgery, but who do not have Alagille syndrome to see if bleeding conditions and complications are more or less common in children with Alagille syndrome.