Long-term renal and hematologic effects of uninephrectomy in healthy feline kidney donors

Abstract

Summary To assess long-term hematologic and renal effects associated with a solitary kidney, 16 healthy cats undergoing uninephrectomy for kidney donation between May 1987 and January 1991 were evaluated by use of physical examination, CBC, serum biochemical analysis, urinalysis, and urine protein:creatinine ratio. Results of preoperative CBC, serum biochemical analysis, and urinalysis were within reference limits in all donors. Median age at surgery and at follow-up evaluation was 34 and 72 months, respectively. Mean (± SEM) interval between follow-up and uninephrectomy was 39.3 ± 14.6 months. Postuninephrectomy hematocrit and RBC indices were within reference limits in 15 donors. One cat with chronic renal insufficiency had normocytic, normochromic, nonregenerative anemia. In 15 clinically normal donor cats, mean (± SEM) serum creatinine concentrations pre- and postuninephrectomy were 1.36 ± 0.20 and 1.71 ± 0.33 mg/ dl, respectively (P = 0.0002); however, the clinical relevance of this statistical difference in serum creatinine is uncertain, because all values were within reference limits. In addition, urine-concentrating ability was maintained in 14 donors, with urine specific gravity > 1.040. Two donors, including the cat with chronic renal insufficiency, produced dilute urine (specific gravity < 1.020) and had substantial proteinuria, with urine protein:creatinine ratios of 2.16 and 3.62, respectively. Mean urine protein:creatinine ratio in donor cats was not significantly different from that in an age- and sex-matched comparison group. Renal and erythropoetic function was clinically preserved in the group of donor cats within 2 to 5 years after uninephrectomy. Findings from this study were supportive of the use of living donors for renal allograft transplantation in cats.