Renal Artery Stenosis
Renal artery stenosis is the narrowing of one or both of the renal arteries. The renal arteries are the main route for blood supply to the kidney for both filtration and nourishment of that tissue. Narrowing of these arteries can cause a number of different conditions stemming from the kidney sensing decreased blood flow through the kidney to the narrowed part serving as a sort of trap for debris floating in the blood.
Renal artery stenosis is characterized by atherosclerosis of the artery. Primarily this develops in men over 50 years of age, typically targeting the segment of the renal artery closest to the heart. As this narrowing of the vessel progresses, it tends to display clinically relevant symptoms as the lack of adequate blood flow has causes wasting of the kidney and ultimately kidney failure.
Renal Artery Stenosis
Chronic progressive blockage of this artery show signs of hypertension and renal failure. The hypertensive condition results from the body’s attempt to compensate for progressively decreased blood flow through the kidney. As the body senses this, it releases a hormone called Aldosterone. Aldosterone functions to retain water primarily through sodium retention. It also stimulates a feeling of thirst. This extra water volume in the body causes hypertension.
Treatment for renal artery stenosis is primarily surgical. In severe renal artery stenosis a by-pass graft is appropriate. If a kidney has been deprived of blood, and therefore oxygen, and is unlikely to regenerate when adequate blood flow is restored, those segments will also be removed. Surgery is usually quite effective curing or attenuating 60-70% of hypertensive patients.
Surgery is not warranted in all instances of renal artery stenosis. There is a procedure called percutaneous transluminal angioplasty (PTA). If stenosis results from fibromuscular dysplasia, PTA is preferred.