Living donor liver transplants (LDLT) from directed and non-directed living donors continue to expand the organ donor pool in the United States, shortening wait times for surgery, lowering Model for End-Stage Liver Disease (MELD) scores at transplant, and decreasing waitlist deaths, according to a review article in Liver Transplantation.

“LDLT is an important surgical modality to increase opportunities for life-prolonging transplant surgeries,” lead author Kiran Bambha, MD, and colleagues wrote.

“Although LDLT has expanded in the United States over the past several years, we have important opportunities for more progress. The liver transplant community is focused on novel initiatives aimed at expanding LDLT access, indications, technologies, and training, which are summarized in this review,” Dr. Bambha tells Physician’s Weekly.

The number of liver transplant surgeries increased to over 10,000 in 2023, with 94% of livers coming from deceased donors while around 20% of potential recipients died on the waitlist. Expanding the living donor pool can improve outcomes for LDLT recipients and help relieve the demand for deceased donor liver transplants.

Innovative Training Needed

LDLT programs at transplant centers throughout the US are growing, and the need to prioritize training the current and future transplant surgery workforce is increasing.

“LDLT offers transplantation to more patients and provides the liver transplant community the opportunity to innovate in ways that will best serve more patients in the future,” Dr. Bambha says.

ADVANCES AND CHALLENGES IN LDLT

❯ LDLT requires ethical decisions. LDLT benefits the recipient while carrying a roughly 0.2% mortality rate and a 30% to 40% complication rate for the healthy donor. The need for LT must be weighed, and both donor and recipient must understand their “risk:potential benefit” ratios

❯ The procedure can prolong the lives of candidates with lower MELD scores and lower stages of cirrhosis who are at risk for liver-related morbidity and mortality while on the waitlist. In one ten-year analysis of transplant registry data, LDLT added 13-17 life-years to recipients compared to patients who remained on the waitlist.

❯ Grade 3 acute-on-chronic liver failure has a 28-day mortality as high as 100%, but in studies, 1-year post-LT survivals in patients with the disease have been up to 80%, with higher percentages in grades 1 and 2.

❯ LDLT has no upper age limit for candidacy and is increasingly available to older donors and recipients. By 2030, around 20% of Americans will be over 65, and that percentage will likely increase, along with the need for LT. Providers worldwide are now more willing to accept older donors, and data suggest that transplant among selected older living donors and recipients can be safe.

❯ Hepatic steatosis (HS) is common in living and deceased donors. The potential negative impacts of excessive HS (>30%-60%, measured on liver biopsy) for deceased donor grafts liver are serious and wide-ranging, but some LT programs consider deceased donor grafts with up to 60% steatosis. “Since HS beyond a certain severity potentially risks donor safety, particularly with right lobe donation, many LDLT programs do not consider donors with more than mild HS,” the authors wrote.

❯ Transplant oncology has proliferated in recent years, extending the lives of carefully selected patients with primary and metastatic malignancies, including those with advanced hepatocellular carcinoma beyond Milan criteria, locally advanced intrahepatic cholangiocarcinoma, and nonresectable colorectal cancer liver metastases, the third most common cancer and the second leading cause of cancer-related deaths worldwide.

The advantages of LDLT over deceased donor liver transplant in transplant oncology include shortened wait times, careful assessment of tumor treatment response before transplant, decreased risk for tumor progression, and surgery scheduling that accommodates neoadjuvant chemotherapy.

The main goal of the two-stage LD-RAPID transplant oncology procedure is to reduce the donor’s risk, although it may increase the recipient’s risk.

❯ Non-directed living liver donation usually involves an anonymous healthy person voluntarily donating part of their liver to another person.

❯ Liver paired exchanges between incompatible living donor-recipient pairs, usually due to blood type or anatomy mismatch. The procedure may involve simple 2-way exchanges or living donor chains with multiple donor-recipient pairs.

❯ Domino liver transplant involves a liver transplant from one person with metabolic disease into another person with end‐stage liver disease. The domino donor gets a deceased-donor liver or a segment of live‐donor liver.