Medical Grand Rounds: refractory hypertension and renal insufficiency in a patient with renal artery stenosis.

Renal artery stenosis has become increasingly common as a cause of refractory hypertension and renal insufficiency. There is a high prevalence of bilateral disease and the lesions tend to progress over time. Newer, less invasive, imaging modalities such as doppler ultrasound, magnetic resonance angiography, and spiral CT scanning are evolving technologies in the diagnosis of renal artery stenosis. Advances in surgical technique, particularly the development of extra-anatomical procedures such as spleno-renal and hepato-renal by pass, have significantly lowered surgical morbidity and mortality and provides revascularization options for patients with complex vascular disease that would previously not have been considered because of their high surgical risk. Improvements in angioplasty technique and the use of stents are broadening the types of lesions that can be successfully approached with these techniques and may be particularly helpful for patients with more severe cardiac or cerebrovascular disease. The benefits of revascularization may be even greater for preservation of renal function than for control of blood pressure in properly selected patients. It is difficult to predict which patients will benefit from surgical revascularization versus medical management of RAS. Knowledge of the progressive nature of RAS, the high prevalence of bilateral disease, and the clinical characteristics that correlate with progression (e.g., decreasing renal size) are helpful in guiding clinical decisions regarding intervention. Additional studies to determine the predictive value of non-invasive tests such as CRS, doppler ultrasound before and after administration of angiotensin converting enzyme inhibitors, and other tests, are needed to assist the clinician in identifying who will benefit most from revascularization both in terms of renal function and blood pressure control.