Controlled Attenuation Parameter for the Evaluation of Donor Steatosis in Living Donor Liver Transplantation

Living donor liver transplantation (LDLT) has been increasing worldwide due to the critical shortage of cadaveric donors and the rising number of patients awaiting liver transplantation. The long-term survival rates of LDLT are now comparable to that of deceased donor liver transplantation. Currently, two-thirds of all liver transplants performed in Hong Kong are LDLT.

The ultimate goal of LDLT is to guarantee donor safety while optimizing the best possible recipient outcome. Donor liver steatosis is a well-known factor which could influence graft function and long-term outcomes of the recipient allograft, and also affects donor hepatic recovery. When needed, pre-operative liver biopsy is often used for the quantitative assessment of donor steatosis, with LDLT not recommended when steatosis exceeds 30%. Nonetheless, liver biopsy is limited by its invasive nature, sampling error and intra-observer variations. Imaging evaluation for the quantification of steatosis via ultrasonography or computed tomography also has various pitfalls. There is currently no universal consensus on the ideal method in assessing donor steatosis.

Controlled attenuation parameter (CAP) is a novel non-invasive method to quantify hepatic steatosis using ultrasonic attenuations to postulate fat content. It has been demonstrated to have good correlation with the degree of hepatic steatosis in both Western and Asian populations. The investigators aim to evaluate the application of CAP in the donor workup of LDLT and to investigate for its association with post-transplant outcomes.