Renovascular hypertension

Renovascular hypertension is the most prevalent form of curable hypertension. Despite some unanswered questions, there is a growing consensus about the need to identify patients with renovascular hypertension so that a specific therapy can be recommended. The renin-angiotensin system is the chief pathophysiologic mechanism responsible for hypertension in patients with renal ischemia but other, yet poorly defined, mechanisms may be operative. Most patients with renovascular hypertension do not present with typical or discriminative clinical features. Thus, many physicians do not perform work-up to uncover renovascular disease even if diagnosis is dictated by patients' clinical course. It is difficult to make the proper diagnosis unless there is a high index of suspicion and certain procedures are performed. How can we, then, select a few patients for the work-up from the vast sea of people with hypertension? The identification of such patients and the pursuit of a renovascular etiology is a matter of clinical judgment. Delineation of renovascular hypertension should be undertaken only after careful deliberation. When clinical clues suggestive of renovascular hypertension are present, appropriate diagnostic tests should be undertaken in patients who are candidates for PTRA or surgery. Captopril-stimulated PRA test is done first. If the test is positive (and in some clinically relevant circumstances even if it is not done or is negative), DSA should be obtained. IV-DSA is being steadily replaced by the superior IA-DSA. The need for renal vein renin determination varies from center to center, but when carefully performed, it yields meaningful information. Ultimately, a conventional arteriogram is done to define the extent of renal artery stenosis and to assess intrarenal vascular anatomy. For selected patients, the benefit-risk ratio clearly outweighs the cost considerations. The spectrum of renovascular hypertension is variable, further compounding the diagnostic indications and contraindications. At one end of this spectrum are those patients in whom surgical therapy is likely to be beneficial, and at the other end are the patients who have relative contraindications to surgery. In between lies the vast gray zone that constitutes a great judgmental challenge in clinical medicine. What is to be done with the patients who have mild to moderate renovascular hypertension whose BP is controlled on medical therapy? There are some patients who may benefit from renovascular repair despite the nonlateralization of renal vein renins. What is the mechanism underlying their hypertension?(ABSTRACT TRUNCATED AT 400 WORDS)