Relationship between bovine carotid artery grafts for hemodialysis access and human leukocyte antigen sensitization.

Introduction: Bovine carotid artery (BCA) Artegraft is a biologic graft that can be utilized as a conduit for permanent hemodialysis access and has been shown to outperform polytetrafluoroethylene grafts. However, concern regarding immunologic sensitization may limit the use of BCA in the transplant candidate. Panel reactive antibody (PRA) is an immunological test utilized in transplant recipient selection whereas increases in PRA limit access to transplantation. The purpose of our study was to determine whether BCA graft placement was adversely associated with increases in PRA.

Methods: Of patients listed for kidney transplant at our institution, we identified 10 patients who underwent BCA placement for hemodialysis access and a matched cohort of 10 patients who underwent native arteriovenous fistula (AVF) creation between 2014 and 2017. The PRA value nearest to the surgery date was compared to postsurgery PRA value for the BCA and AVF patients using a paired t test. Presurgery PRAs were also compared to the maximum PRA at 0 to 6, 6 to 12, 12 to 18, and 18 to 24 months postsurgery.

Findings: Prior to the dialysis access operation, the mean PRA was 14.1% ± 23.5% vs. 17.1% ± 29.0% (P = 0.76) and the median postsurgery follow-up time was 16 and 15 months for BCA and AVF cohorts, respectively. There were no statistically significant differences between presurgery and postsurgery PRA for BCA and AVF patients, regardless of time interval postsurgery. The difference in presurgery/postsurgery PRA change between cohorts was not statistically significant for PRAs closest to surgery (0.2% ± 40.6% vs. 1.0% ± 2.8%, P = 0.95, at a median 4 and 3 months postsurgery, respectively) or when using the maximum in any postsurgery interval. Prior to their dialysis access surgery, there were 16 sensitizing events in 5 patients in the BCA group compared to 10 events in 5 patients in the AVF group (P = 0.20). Only 1 of the 10 patients in the BCA group had a clinically relevant and sustained increase in PRA following their dialysis access operation vs. no patients in the AVF group (P > 0.99). However, this patient had a known sensitizing event (blood transfusion) between the BCA surgery and the postoperative PRA. Three of 10 patients in the BCA cohort vs. 5 of 10 patients in the AVF cohort went on to have successful kidney transplants (P = 0.65).

Discussion: The utilization of BCA for dialysis access was not associated with statistically significant changes in PRA. These data suggest that implantation of BCA will not affect access to organ transplantation.