Pediatric living donor left lateral segment liver transplantation biliary atresia: Doppler ultrasound findings in early postoperative period

WHY THE STUDY WAS PERFORMED:

To determine normal changes of hepatic hemodynamic measurements in the immediate period following transplant of a left lobe cutdown in paediatric patients. To use that data to create valuable reference values for sonographers, radiologists, and treating clinicians that will assist in better identifying early postoperative vascular complications versus normal post operative changes.

HOW THE STUDY WAS PERFORMED:

The study was a retrospective analysis of 227 biliary atresia patients who had undergone left segment liver transplant, with a total of 1135 Doppler examinations performed in the first week post-transplant.

The examinations were reviewed and the hemodynamic measurements including peak systolic velocity (PSV), end diastolic velocity (EDV), resistive index (RI) and pulsation index (PI) of the hepatic artery, the portal vein velocity and flow, and the hepatic vein velocities were documented. This information was collected from the intra-operative scan, and those examinations performed on the first, third, fifth, and seventh-day post operation. The examinations were performed by experienced staff.

The liver function tests were also collected for each day for correlation. The data was then analysed to determine trends over the week period. The patients included all recovered normally after transplant with normal function achieved.

WHAT THE STUDY FOUND:

The study found that the biochemical liver function markers improved over the week posttransplant, as the patient recovered. The Doppler parameters and measurements demonstrated a consistent change during the post operative period assessed, especially the Hepatic artery (HA). The HA PSV & EDV demonstrated a decrease over the first few scans to day 3, with a consequent rise on the day 5 and 7 examinations. Conversely the hepatic artery PI & RI demonstrated the opposite trend with a rise in value to day 3, followed by a decrease on day 5 and 7. The portal vein measurements, velocity and flow were found to vary widely, however a reference range for each day was established.

Doppler ultrasound was able to quantitively monitor the changes in hepatic hemodynamic parameters and normal reference values were able to be established. The authors conclude that the results obtained suggest that patients with measurement values below the reference values during the immediate post operative period may need to be monitored more closely.

RELEVANCE TO CLINICAL PRACTICE:

Though performed at a single centre, this article is a good beginning to better understanding the flow changes in left lobe cut-down transplants in the first week post-operation. During the first week post-transplant there is a higher risk of vascular complications for these patients and by understanding normal changes it is easier to identify actual complications. This article will be especially relevant to paediatric sonographers who perform these studies, and to help those who are less experienced to understand the normal hemodynamic changes expected post-transplant. n

REVIEWED BY Cain Brockley ASA SIG Paediatric

REFERENCE Tang, Y. Zhang, G. Kong, W., et al. Japanese Journal of Radiology

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“Understanding normal flow dynamic changes in the immediate post-transplant period assists in separating vascular complications from normal expected changes.”