BACKGROUND: The transplantation of a single kidney, while its partner kidney is discarded despite both having been initially offered (dual-offered, single-transplanted; DOST), represents a missed opportunity to preserve nephron mass and optimize donor utilization. Dual kidney transplantation (DKT) preserves nephron mass by transplanting both kidneys from a higher-risk donor, but its benefits relative to DOST remain underexplored.

METHODS: In this nationwide multicenter cohort (2008–2021), we analyzed 36 DKT and 20 DOST recipients. Both groups were propensity-matched 1:2 to 112 regular single-kidney transplant recipients (RegT) based on donor and recipient characteristics. The primary endpoint was estimated glomerular filtration rate (eGFR) at 12 months. Secondary endpoints included eGFR through 5 years, death-censored graft and patient survival, perioperative metrics, and 12-month quality of life (EQ-5D). RESULTS: At 12 months, median eGFR was higher in DKT (50.8 ml/min/1.73 m2) than DOST (33.5 ml/min/1.73 m2) or RegT (38.0 ml/min/1.73 m2; p < 0.001), with differences sustained through 5 years. Graft and patient survival were similar. DKT involved longer surgery (270 vs. 163 min; p < 0.001), greater blood loss (550 vs. 300 ml; p = 0.084), and more transfusions (75% vs. 30%; p = 0.0017) but no increase in delayed graft function or major complications. EQ-5D scores were higher in DKT (85.0) than DOST (70.0) and RegT (71.0; p = 0.048).

CONCLUSION: DKT is an effective approach for higher-risk donor kidneys and was associated with higher graft function and quality of life. Despite increased operative complexity and transfusion requirements, there was no evidence of increased postoperative morbidity. Broader adoption may reduce unnecessary kidney discards and improve transplant outcomes, although findings should be interpreted in light of the limited sample size and observational design.