The Effect of Transplant Volume and Patient Case Mix on Center Variation in Kidney Transplantation Outcomes

Living-Donor Kidney Transplantation Performed in a Low-Volume Center by Visiting Surgeons From a High-Volume Center and Managed Clinically Solely by Nephrologists: 1-Year Outcomes

BACKGROUND

Little is known about the outcome of living-donor kidney transplantation (LDKT) performed in low-volume centers lacking the services of full-time transplant surgeons. This retrospective cohort study assessed the outcome of LDKT performed in a low-volume center by visiting transplant surgeons from a high-volume center and managed perioperatively by transplant nephrologists.

METHODS

We compared Japanese adult patients who had no donor-specific antibodies and underwent LDKT between 2006 and 2015 either in a low-volume (n = 31) or high-volume (n = 481) center. In the low-volume center, visiting transplant surgeons from the high-volume center conducted LDKT and transplant nephrologists managed the recipients peri- and postoperatively. The primary outcome was the composite of infection, cardiovascular disease, or cancer during 1-year follow-up. The outcomes of the low- and high-volume centers were compared using 1:2 propensity score matching.

RESULTS

After matching, 9 of 29 patients in the low-volume center (31.0%) and 16 of 58 patients in the high-volume center (27.6%) experienced the primary composite outcome (risk ratio = 1.13; 95% confidence interval, 0.57-2.23). There were no significant differences between the 2 groups in graft function at 1 year, all-cause graft loss, biopsy-proven rejection, and urological complications. However, the median duration of post-LDKT hospitalization was significantly longer in the low-volume center than in the high-volume center (23 and 16 days, respectively).

CONCLUSIONS

Among Japanese patients without preformed donor-specific antibodies, LDKT conducted at a low-volume center by visiting transplant surgeons from a high-volume center and managed clinically by transplant nephrologists was not associated with significantly higher risk of postoperative complications.

Patient and center characteristics associated with kidney transplant outcomes: a binational registry analysis

This registry-based study evaluated the contribution of center characteristics to kidney transplant outcomes in adult first kidney transplant recipients in Australia and New Zealand between 2004 and 2014. Primary outcomes were mortality and graft failure, and secondary outcomes were transplant complications. Overall, 6970 transplants from 17 centers were included. For deceased donor transplants, 5-year patient and graft survival rates varied considerably (81.0-93.9% and 72.2-88.3%, respectively). Variations in mortality and graft failure were partially reduced after adjustment for patient characteristics (1% and 20% reductions) and more markedly reduced after adjustment for center characteristics (41% and 55% reductions). For living donor transplants, 5-year patient and graft survival rates varied (89.7-100% and 79.2-96.9%, respectively). Centers with high average total ischemic times (>14 h) were associated with higher mortality for both deceased (adjusted hazard ratio [(AHR] 2.24, 95% CI 1.21-4.13) and living donor transplants (AHR 1.76, 95% CI 1.02-3.04). Small center size (<35 new kidney transplants/year) was associated with a lower hazard of mortality for living donor kidney transplants (AHR 0.48, 95% CI 0.28-0.81). No center characteristic was associated with graft failure. The appreciable variations in deceased donor kidney transplant recipient and graft survival outcomes across centers were attributable to center effects.