[Imaging of complications of liver transplantation in children].

The authors report their experience of imaging of 286 liver transplantations (LT) in children. Hepatic artery thrombosis is the most serious complication (9%), with a maximum risk during the first two weeks. Its clinical presentation is very variable and its diagnosis is based on Doppler ultrasonography. Emergency surgical disobstruction prevented the development of biliary or ischaemic complications in one half of cases. Portal thrombosis (4.5%) is due, in the majority of cases, to hypoplasia of the recipient's portal vein. Patency of intrahepatic portal branches with inversion of flow can delay the ultrasonographic diagnosis. Biliary complications are frequent (20%) and occur after a very variable interval. Their diagnosis is ultrasonographic, but sometimes delayed compared to the histological signs. Transhepatic cholangiography visualises the lesions and allows external drainage or even percutaneous dilatation. In 1 out of 4 cases, the aetiology was hepatic artery thrombosis. The imaging protocol after LT consists of ultrasonography with daily Doppler (or even twice-daily) in the patient's bed for the first two weeks and then as required. Computed tomography is useful to demonstrate parenchymal ischaemia and intraperitoneal abscess in multi-operated children. Angiography and cholangiography confirm the ultrasonographic signs. Interventional Radiology plays an increasingly important role.