Association between donor kidney cysts and donor and recipient outcomes after living donor kidney transplantation.

INTRODUCTION:Incidental kidneys cysts are typically considered benign, but the presence of cysts is more frequent in individuals with other early markers of kidney disease. We studied the association of donor kidney cysts with donor and recipient outcomes after living donor kidney transplantation. METHODS:We retrospective identified 860 living donor transplants at our center (1/1/2011-7/31/2022) without missing data. Donor cysts were identified by review of pre-donation CT scan reports. We used linear regression to study the association between donor cysts and 6-month single-kidney estimated glomerular filtration rate (eGFR) increase, and time-to-event analyses to study the association between donor cysts and recipient death-censored graft failure. RESULTS:Among donors, 77% donors had no kidney cysts, 13% had ≥1 cyst on the kidney not donated, and 11% only had cysts on the donated kidney. In adjusted linear regression, cysts on the donated kidney and kidney not donated were not significantly associated with 6-month single-kidney eGFR increase. Among transplants, 17% used a transplanted kidney with a cyst and 6% were from donors with cysts only on the kidney not transplanted. There was no association between donor cyst group and post-transplant death-censored graft survival. Results were similar in sensitivity analyses comparing transplants using kidneys with no cysts versus 1-2 cysts versus ≥3 cysts. CONCLUSIONS:Kidney cysts in living kidney donors were not associated with donor kidney recovery or recipient allograft longevity, suggesting incidental kidney cysts need not be taken into account when determining living donor candidate suitability or the laterality of planned donor nephrectomy.