Assessment of hepatic artery anatomy in pediatric liver transplant recipients: MR angiography versus CT angiography

Abstract

Currently, the only therapeutic option for children with ESLD is LT.Overall survival of the patient and the liver graft directly depends on several potential complications during and after transplantation.The most threatening complications are arterial and venous thrombosis, anastomotic stenosis, and kinking of vessels. 1 Other important perioperative concerns are extensive hemorrhage, infection, and early rejection. To minimize the perioperative complication risk, a thorough preoperative work-up is necessary.Prior to LT, the anatomy and patency of the hepatic artery, portal vein, liver veins, and inferior caval vein need to be assessed. Of these, the hepatic artery anatomy is the most challenging to image.Hepatic artery variants, such as accessory vessels or replacement of the artery where the hepatic artery origin is not the coeliac trunk, have been reported to occur in up to 45% of patients. 2,3 By identifying vascular variants and vessel caliber, the hepatobiliary surgeon is able to select the largest caliber artery for anastomosis, decide on suitability for a match with a living donor graft, and plan required microvascular reconstructions. 4

European Society of Pediatric Radiology survey of perioperative imaging in pediatric liver transplantation: (1) pre-transplant evaluation

“…Their common indication is delineation of the child’s vascular anatomy, essentially representing the backbone for later transplantation. CT angiography can depict vascular anatomy also in young children with very high accuracy and may be the best method to show subtle hepatic artery anomalies [ 5 , 14 ].…”

“…Compared to CT, fewer centers use abdominal MRI to image vascular anatomy. The most applied technique is 3-DMRA which may show slightly inferior accuracy to CT angiography for depiction of arterial anatomy as suggested by adult and a few pediatric studies [ 5 , 14 , 31 ]. However, with newer MRI techniques (e.g., 3-tesla MRI, time-resolved contrast-enhanced MRA), the state-of-the-art techniques may change soon and should be the object of future comparative studies [ 14 ].…”

“…While US exhibits relatively high accuracy in evaluating the pre-transplant abdominal status compared to intraoperative findings, CT and magnetic resonance imaging (MRI) are occasionally employed to offer greater detail and a reproducible roadmap for technically complex operations [ 12 ]. Nevertheless, these cross-sectional modalities present distinct advantages and disadvantages concerning availability, anatomical structure visualization, accuracy, and potential risks to the patient, such as anesthesia, examination duration, radiation exposure, and use of contrast agents [ 5 , 12 , 14 ].…”

Current Endovascular Management of Arterial Complications After Pediatric Liver Transplantation in a Tertiary Center

“…The importance of including CTA in the diagnostic algorithm was confirmed in our experience by the incidental detection of pseudoaneurysms, which are rare but potentially catastrophic complications of LT [ 7 , 19 ]. The high diagnostic value and the short examination time of CTA overweight the risk related to iodinated contrast, ionizing radiations, and the need to sedate pediatric patients [ 20 ]. Some research suggested that safe conservative management of asymptomatic HA occlusion is possible [ 21 ], thanks to neoangiogenesis, which could permit a long-term survival, although in turn favoring the development of chronic thrombosis, especially in the pediatric population [ 22 ].…”

Liver cirrhosis in children – the role of imaging in the diagnostic pathway

“…Due to the increased risk of ionizing radiation, CT is mainly advocated for extended staging to exclude lung metastasis or when MRI is not possible. CT is faster than MRI, has excellent spatial resolution and has advantages in depicting vascular anatomy before surgery and before liver transplantation [ 115 ]. If surgical resection of HCC is not possible, liver transplantation has been shown to be a curative option, with a 5-year disease-free survival of 84.5% [ 116 ].…”