Renal Artery Intervention

Renal artery stenosis is caused because of narrowing of the renal arteries. The kidneys perform functions such as removal of body waste in the form of urine, and regulation of the blood pressure by secreting a hormone, renin. If the kidney arteries are narrowed or have a clot, the kidneys will not function properly causing your blood pressure to rise which will further lead to kidney failure.

Renal artery stenosis may not have any symptoms. The disease develops slowly. The first sign of renal artery stenosis if you have high blood pressure is worsening of the high blood pressure and uncontrolled hypertension even with use of antihypertensive medications. Other signs are a whooshing sound in your abdomen that your physician hears through a stethoscope, decreased kidney functions, congestive heart failure, or a small shrunken kidney.

Renal artery stenosis is caused due to hardening of renal arteries. Normally, your arteries are smooth and unobstructed on the inside but a sticky substance called ‘plaque’ builds up in the artery walls because of dyslipidemia or presence of both diabetes and hypertension. Plaque is made up of cholesterol, calcium, and fibrous tissue which hardens and stiffens the arteries. This process is called as atherosclerosis, or hardening of the arteries. Formation of plaque in the renal arteries will restrict the blood flow in the renal arteries.

Early detection of the disease is important before it leads to complications like renal failure and severe hypertension. Blood tests and kidney function tests are done to evaluate the kidney functions. Other diagnostic tests such as Duplex ultrasound scan, CT scan, and angiography are done to detect the exact location of the blockage.
Your doctor will prescribe certain medications to control blood pressure like diuretics, beta-blockers, calcium channel blockers, and angiotensin-converting enzyme (ACE) inhibitors.

The two procedures used to treat the narrowing of renal arteries are balloon angioplasty and coronary stenting.

• Balloon angioplasty –In this technique, your surgeon inserts a catheter through a small needle which passes through the blood vessels into the renal arteries. The catheter carries a small balloon that inflates and deflates. When this is passed into the blocked artery, the balloon is inflated which will push the plaque against the artery wall helping the artery allow more space to increase the blood flow.
• Stenting – It is performed during an angioplasty procedure. Stent is an artificial device, a mesh-like tube which is made up of stainless-steel that has the ability to expand inside the blocked artery. Stents are mounted on narrow tube (catheter) which has a deflated balloon towards the end. This stent is inserted into the blocked artery and the balloon is inflated which allows the stent to expand inside the artery. Later the balloon is deflated and removed.