What is Renal Artery Stenosis?

Renal artery stenosis is usually caused by atherosclerosis and fibromuscular dysplasia, and can also be caused by takayasu's arteritis. Renal artery stenosis often leads to renal vascular hypertension, which is stimulated by renal ischemia causing renin secretion. General pharmacological therapy cannot halt the progression of renal artery stenosis, and various dietary adjustments are also necessary for this condition. So, what exactly is renal artery stenosis? Renal artery stenosis is often caused by atherosclerosis and fibromuscular dysplasia, and can also be caused by takayasu's arteritis. Atherosclerosis is the most common cause, accounting for about 80% of patients with renal artery stenosis, and is mainly seen in the elderly. The latter two causes are mainly seen in younger individuals and women. Renal artery stenosis often leads to renal vascular hypertension, which is stimulated by renal ischemia causing renin secretion, activation of the renin-angiotensin-aldosterone system (RAAS), peripheral vasoconstriction, and water and sodium retention. Renal artery stenosis caused by atherosclerosis and takayasu's arteritis can also cause ischemic nephropathy, where renal ischemia on the affected side can lead to glomerular sclerosis, tubular atrophy, and renal interstitial fibrosis.

Pharmacological therapy cannot halt the progression of renal artery stenosis, but it can help control hypertension and improve symptoms. For patients with unilateral renal artery stenosis and high renin levels, ACE inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) are usually the first choice, but they must be started at a low dose and gradually increased to avoid a rapid or excessive drop in blood pressure. These medications should be avoided in patients with bilateral renal artery stenosis. To effectively control blood pressure, various antihypertensive medications are often required. Percutaneous transluminal renal angioplasty (PTRA) is frequently performed, using a balloon to dilate the renal artery. This treatment is particularly suitable for patients with fibromuscular dysplasia. Since patients with atherosclerosis and takayasu's arteritis are prone to restenosis after dilation, these patients should have a stent placed after dilation.