Long-term outcomes following arteriovenous fistula ligation in kidney transplant recipients

Abstract

BACKGROUND

Arteriovenous fistulae (AVFs) are the preferred mode of vascular access amongst patients with end-stage kidney disease, and many remain patent following kidney transplantation. While emerging evidence demonstrates cardiovascular benefits to AVF ligation post-transplantation, current guidelines provide no clear consensus on the management of functioning AVFs post-transplant. Additionally, the impact of AVF ligation on allograft outcomes is unclear. Therefore, clarifying the potential benefits of post-transplant AVF ligation is clinically important.

AIM

To investigate the clinical impact of AVF ligation post-transplantation and compare the outcomes in kidney transplant recipients on dialysis via a central venous catheter (CVC) vs AVF prior to transplantation.

METHODS

Kidney transplant recipients who had undergone AVF ligation or excision at a single center (n = 176) were identified using electronic health records. Two comparator groups were selected: Recipients with AVFs who had not undergone AVF ligation, and recipients who were ‘AVF-free’, having received hemodialysis via a CVC. Patient and allograft outcomes were captured via a prospectively maintained transplant database. The median follow-up post-AVF ligation was 90 months.

RESULTS

There were significant differences in patient characteristics between transplant recipients undergoing post-transplant AVF ligation vs non-ligation; the former were more likely to be female (P = 0.045), younger (P = 0.002), and non-diabetic (P < 0.001). There were further differences in patient and allograft characteristics between recipients with pre-transplant AVF vs CVC. Patients receiving dialysis via pre-transplant CVC had superior death-censored allograft survival compared with patients with pre-transplant AVFs [hazard ratio (HR): 0.74, 0.57-0.97, P = 0.028]. Post-transplant AVF ligation was associated with improved death-censored allograft survival amongst kidney transplant recipients compared to non-ligation (HR: 0.42, 0.26-0.66, P < 0.001). There were no differences in mortality rates.

CONCLUSION

Post-transplant AVF ligation may improve allograft survival. However, due to significant differences between patients undergoing AVF ligation vs non-ligation, these findings are susceptible to selection bias and should be interpreted cautiously. Randomized controlled trials are needed in patient groups who may stand to benefit the most from cardiovascular protection from AVF ligation.

Keywords: Arteriovenous fistula; Arteriovenous fistula ligation; Kidney transplantation; Allograft survival; Hemodialysis access

Core Tip: This study examines long-term outcomes following arteriovenous fistula (AVF) ligation in kidney transplant recipients, a topic with limited prior evidence. In this large, single-center cohort with extended follow-up, post-transplant AVF ligation was independently associated with improved death-censored allograft survival without differences in patient mortality. Furthermore, recipients who were “AVF-free” from transplantation, having previously been on dialysis via central venous catheter, demonstrated similarly superior allograft survival compared to those with pre-transplant AVFs. These findings suggest that the presence of AVFs may influence graft longevity, and post-transplant ligation may confer graft survival benefits in addition to previously reported cardiovascular advantages.