Predictive value of quantitative renography for successful treatment of atherosclerotic renovascular hypertension

Twenty patients with severe atherosclerotic renal artery stenosis were studied by quantitative gamma camera renography before angioplasty or surgery. Sixteen patients were treated by angioplasty and two each by bypass surgery and nephrectomy. Total and relative renal function, renal perfusion, and tracer transit times through the affected and contralateral kidney were calculated. All but one of the angioplasty patients and one of the two bypass surgery patients also had quantitative renography performed one to two weeks after treatment to assess changes in renal function. In the remaining four patients, changes in renal function were assessed by serial serum creatinine estimations. Patients were classified as cured, improved, or not improved according to their blood pressure response. Five had evidence of unilateral functionally significant stenoses and normal contralateral kidneys (four cured, one improved). Ten had functionally significant stenoses but with abnormal contralateral kidneys (all improved). Five had no evidence of functionally significant stenoses (all not improved). Quantitative renography provides functional and prognostic information to complement anatomical assessment by angiography. It is a simple, safe, and non-invasive means of predicting the outcome for patients with hypertension and renal artery stenosis.