Purpose or Case Report: Pediatric liver transplant (PLT) is an established treatment for many hepatic conditions in children. In recent years there has been a significant increase in the number of PTL associated with an improved survival. In children however, due to the complex surgical procedures and peculiar hemodynamic physiology there is also an increased risk for vascular and biliary complications. High resolution ultrasonography (US) is the modality of choice to evaluate and monitor the evolution of pediatric liver graft. This exhibit intends to illustrate fellows and residents with the US characteristics of the normal hepatic anatomy, the normal early and late US appearances of the graft, and the US features of complications that may compromise graft’s survival.
Methods & Materials: This exhibit starts with a quiz. Same questions are again asked at the end of the presentation, and it is our expectation that the reader will be able to answer them. Then we briefly describe the common indications of liver transplant in children, types of transplants and surgical approaches in children. We define the gray scale and Doppler US features of the normal liver, and the normal graft, including the hepatic artery (HA) velocities and the normal resistive indexes (RI) of day 1 and 3 post-transplant. We also describe the common vascular and biliary complications with its sonographic features and representative examples. Finally, we include illustrative cases of other extra-hepatic complications including collections, arterio-venous fistulae, and post-transplant lymphoproliferative disease and we provide a “take home” summary of the exhibit.
Results: The most common complications in PTL are biliary-related and include anastomotic leak, strictures, bleeding, or infection. Common vascular complications are hepatic artery, portal or hepatic veins stenosis, and thrombosis. Hepatic artery RI < 0.5 with low systolic velocities (< 50 cm/sec ), monotonic hepatic veins flow with low hepatic vein velocity (<25 cm/sec), and absent or low portal venous flow (< 30 cm/sec), warrant further assessment.
Conclusions: Fellows and residents must be aware of the normal sonographic features of the liver, the early and late postoperative features of the pediatric liver transplant to be able to recognize potential complications. Although, there is no yet established definitive cut off Doppler values to predict graft status in children, recognition of abnormal arterial and venous velocities or spectrum warrant further assessment.