Detection of occult renovascular disease in unexplained chronic kidney disease

Atherosclerotic renal artery stenosis (RAS) is a recognized cause of renal impairment. RAS is often overlooked in unexplained chronic kidney disease (CKD). A retrospective analysis of renal angiograms was performed to determine the prevalence of occult renovascular disease in 64 (M:F, 46:18; ages 21-81 years [median 60 years]) patients with unexplained CKD. Twelve patients had diabetes mellitus (type II: 11) and 43 were smokers. Median serum creatinine was 5.2 mg/dl (range 1.5-10.6 mg/dl). Group A included patients with unexplained CKD and with no risk factors for RAS and Group B had patients with increased risk for RAS. A narrowing of the renal vessel, main artery or branch, by >50% on renal arteriography was used as diagnostic criteria for RAS. 31/64 patients had positive angiographic findings. Thirteen patients had unilateral RAS, 9 had bilateral RAS, 5 had unilateral stenosis with occlusion on the opposite side, 3 had unilateral occlusion and 1 had a solitary kidney with RAS. 19/34 (54%) in Group A and 12/30 (40%) in Group B had a positive renal angiogram. In 10 patients with a rise in serum creatinine on recent introduction of ACE inhibition, 2 had evidence of RAS on renal arteriography. Eleven patients underwent angioplasty and 2 reconstructive surgeries. In 4 patients, blood pressure control improved and anti-hypertensive drug requirements were reduced, whilst renal replacement therapy was postponed in 4, by 2-24 months. In 18 patients, the lesions were not amenable to angioplasty or reconstructive surgery. Four patients did not benefit in any form with intervention. Occult atheromatous renal vascular disease is a common, not readily predictable and potentially correctable etiology of unexplained CKD.