ABO-incompatible liver transplantation - exploring utilitarian solutions to restricted access and organ shortages: A single-centre experience from Johannesburg, South Africa.

Background: Liver transplantation is the definitive management for severe acute liver failure refractory to supportive management, and end- stage chronic liver failure. Owing to a shortage of deceased liver donors, South Africa requires innovative techniques to broaden the donor pool.

Objectives: This study evaluated the outcomes of the Wits Transplant Unit ABO-incompatible liver transplant (ABOi-LT) programme.

Methods: This retrospective record review compared all adult and paediatric patients receiving ABO-compatible (ABOc) and ABO-incompatible (ABOi) liver transplants from January 2014 to December 2021 with a minimum one-year follow-up. Primary outcomes were recipient and graft survival and secondary outcomes included vascular, enteric and biliary complications, relook surgery, acute cellular rejection (ACR) and lenghth of hospital stay. Cox proportional hazards regression was performed to examine the effect of ABO-compatibility group on recipient and graft survival. The relationship between the ABO-compatibility group and categorical outcomes was assessed by binomial regression.

Results: During the study period, 532 liver transplants were performed; 44/532 (8%) were ABOi of which 14/44 (32%) were paediatric and 30/44 (68%) adult recipients. Within the pediatric group, the proportion of transplants performed for acute liver failure was significantly higher in the ABOi group (7/14; 50%) compared with the ABOc group (33/207; 16%) (p=0.005). Comparable recipient and graft survival estimates were noted: one-, three- and five-year recipient survival in the ABOi group was 77% (95% confidence interval (CI) 44 - 92), 58% (95% CI 17 - 84) and 58% (95% CI 17 - 84) respectively. There were significantly increased relative risks of relook surgery for the ABOi group compared with the ABOc group, both overall (relative risk (RR) 1.74; 95% CI 1.10 - 2.75) and at 90 days (RR 2.28; 95% CI 1.27 - 4.11); and also, for pre-discharge bloodstream infection (BSI), (RR 1.84; 95% CI 1.11 - 3.06). In adults, there were significantly more acute indications for liver transplantation in the ABOi (10/30; 33%) compared with the ABOc group (26/281; 9%) (p=0.0007) with the most common cause being drug or toxin ingestion (16/36; 44%). For the ABOi group, recipient survival estimates (95% CI) at 1, 3 and 5 years were 71% (50 - 84), 63% (41 - 78) and 58% (37 - 75) which, as noted with complication rates, were similar between ABO groups.

Conclusion: This study confirms ABOi-LT as a feasible option to increase the liver donor pool in this organ-depleted setting as recipient survival and complication rates were similar between ABO-compatibility groups.