Dual kidney transplantation: older donors for older recipients

Dual kidney transplantation, the transplantation of both donor kidneys into a single recipient, allows increased use of expanded criteria donors (eg, older donors with a history of hypertension) to alleviate the disparity between available donors and potential recipients. We evaluated outcomes in our dual kidney transplant program that started in 1995.

A retrospective comparison of donor and recipient data between recipients of dual (n = 41) versus single (n = 199) cadaveric renal transplants from February 1, 1995, to March 22, 1998, was performed. Dual kidney transplantation was selectively performed when the calculated donor admission creatinine clearance was less than 90 mL/min and the donor age was greater than 60 years, or if the donor had an elevated terminal serum creatinine. Every attempt was made to age- and size-match the donor and recipients.

Recipients of dual kidneys had donors who were older than single kidney donors (59 +/- 12 versus 42 +/- 17 years respectively, p < 0.0001) and had more hypertension (51% versus 29%, p = 0.024). Average urine output was lower in the dual versus single kidney group (252 +/- 157 versus 191 +/- 70 mL/hr, p = 0.036). Donors for dual kidney recipients had a lower donor admission creatinine clearance of 82 +/- 28 mL/min versus 105 +/- 45 mL/min in the single kidney group (p = 0.005). Recipients of dual versus single kidneys were older (58 +/- 11 versus 47 +/- 12 years, p > 0.0001). Dual versus single kidney recipients had similar serum creatinines up to 2 years posttransplant (1.6 +/- 0.3 versus 1.6 +/- 0.7 mg/dL at 2 years, p = NS) and a comparable incidence of delayed graft function (24% versus 33%, p = NS) and 3-month posttransplant creatinine clearance (54 +/- 23 versus 57 +/- 25 mL/min, p = NS). One-year patient and graft survival for single kidney transplantation was 97% and 90%, respectively, and 98% and 89% for dual kidney transplantation (p = NS).

Dual kidney donors were significantly older, had more hypertension, lower urine outputs, and lower donor admission creatinine clearance. Despite these differences, dual kidney recipients had comparable postoperative function, outcomes, and survival versus single kidney recipients. We believe selective use of dual kidney transplantation can provide excellent outcomes to recipients of kidneys from older donors with reduced renal function.