Prevalence of ischemic nephropathy in patients with renal insufficiency

To estimate its clinically unsuspected prevalence among patients with renal insufficiency, renal duplex sonography (RDS) was used to estimate the presence of critical renal artery stenosis (RAS) in that population. Patients, aged 45 to 75 years, with a serum creatinine of greater than or equal to 2.0 mg% but without dialysis dependence, prior renal transplantation, or prior renal artery surgery were considered for RDS. Fifty-three patients who met criteria for study were randomly selected from the Section of Nephrology clinic files and each patient was contacted both by mail and by telephone. Twenty-five patients agreed to RDS, and renal artery anatomy was determined in 21 patients using standardized RDS techniques. These techniques have demonstrated an overall accuracy of 96 and 97 per cent when compared prospectively to conventional angiography during validity analyses in the authors' center. Results of RDS revealed significant findings in 5 of 21 patients (24%). Three patients demonstrated criteria for ischemic nephropathy (IN): one patient had RAS with contralateral renal artery occlusion confirmed by angiography, while 2 patients demonstrated unilateral RAS. An abdominal aortic aneurysm and unilateral hydronephrosis were discovered in the fourth and fifth patients. Evaluation of patient demographic data and functional parameters as predictors of IN revealed that the duration of renal insufficiency at the time of RDS and extra-renal organ-specific atherosclerotic damage were significantly different between the groups with and without IN. The authors preliminary findings suggest that unsuspected ischemic nephropathy may exist in a significant minority of patients with renal insufficiency.