Between November 1991 and January 1999, there were 340 recipients of adult cadaveric kidney-only transplants at our center, excluding recipients of pediatric en bloc transplants. We compared outcomes in recipients of dual ECD kidneys with single younger kidneys (control) and single ECD kidneys. The ECD kidneys were those that were refused by all other local transplantation centers owing to a history of hypertension, donor instability, donor age, pretransplantation biopsy result, or a combination of these factors. When the donor age was 60 years or older and the calculated admission creatinine clearance was 1.50 mL/s (90 mL/min) or less, the kidneys were usually transplanted as a dual transplant. The admission creatinine clearance was calculated using the Cockcroft-Gault equation as previously described.6 Other donor criteria for our dual transplants included severe donor instability, a long history of hypertension, or marked elevation in donor creatinine level after hospital admission. Donors of single ECD kidneys frequently had a history of hypertension, diabetes, or high terminal creatinine clearance. The technique for dual kidney transplantation has been previously described; briefly, the right and left kidneys were placed into the right and left iliac fossa, respectively, via a midline extraperitoneal approach.5 In 3 instances, when both donor kidneys were small and there was minimal aortic atherosclerosis, the kidneys were transplanted en bloc using the donor aorta and vena cava for vascular conduits. Every effort was made to shorten the cold storage time of the dual kidney transplants. We rarely use procurement biopsies in the decision to accept or decline kidneys for transplantation, preferring to use functional parameters such as change in serum creatinine levels, blood pressure stability, and urine output. Frequently, biopsy specimens are obtained near the capsule. In older donors, areas near the capsule are more likely to be ischemic, therefore misrepresenting the amount of glomerular sclerosis. The immunosuppressive strategies for the 3 different cohorts were similar throughout the study period. In general, cyclosporine-based triple therapy was used, which included cyclosporine emulsion after July 1995, azathioprine (which was replaced in July 1995 by mycophenolate mofetil), and prednisolone. We maintained our patients' cyclosporine levels between 350 and 450 ng/mL by whole-blood TDX for the first 6 months after transplantation and lowered the levels to between 150 and 250 ng/mL by the first year. Prednisolone is tapered to 10 mg by 1 month after transplantation. The mycophenolate dose was adjusted from 1 g twice daily based on gastrointestinal and hematologic parameters. Induction therapy, with either OKT-3 or an interleukin 2 inhibitor, was used for sensitized patients (Panel reactive antibody >30%), retransplantations, or African American recipients. We compared 16 donor and 25 outcome variables among the various groups. Donor variables included age, hemodynamics, urine output, history of hypertension or diabetes, admission, peak, and final creatinine levels, creatinine clearance, and biopsy results. Recipient and outcome variables included recipient age, human leukocyte antigen match, cold storage time, preoperative serum creatinine level, creatinine level at 1 week and 1, 3, 12, and 24 months, best creatinine level, length of hospital stay, readmissions, number of rejections, incidence of infections, incidence of complications, peak and transplant Panel reactive antibody, donor-recipient weight ratio, incidence of delayed graft function, and graft loss. Data were entered into a relational database. A multivariate analysis, unpaired t test, or χ2 test was performed accordingly (all data are presented as mean ± SD). Significance was defined as differences with P<.05.