Renal Artery Stenting
Renal artery stenting is a common procedure performed to control renal artery stenosis (RAS), a condition in which the renal arteries have become narrow or blocked. During the procedure, a catheter is inserted through an artery to the affected area. A tiny balloon is inserted through the catheter and is gently inflated to flatten the plaque build up against the artery wall, thus widening the area through which blood can flow. A stent (small mesh or wire tube) is then positioned inside the artery to keep the artery open.
RAS most often results from a severe buildup of atherosclerotic plaque in the renal arteries and is most common in patients older than 50 years of age. Sometimes, however, the condition is present in younger patients due to fibromuscular dysplasia. Fibromuscular dysplasia can occur in arteries in other parts of the body, but most frequently affects the arteries of the kidneys.
Reasons for Renal Artery Stenting
The renal arteries, which deliver blood to and from the kidneys. may become clogged or narrowed, a condition known as renal artery stenosis (RAS). Renal artery stenosis prevents proper blood flow. While sometimes more conservative methods are effective in treating issues stemming from RAS, sometimes surgery, in the form of renal artery stenting, is necessary to restore appropriate blood flow.
RAS can help to alleviate several conditions that may result from RAS, including the following:
- Renovascular hypertension
- Reduced kidney function (ischemic nephropathy)
- Recurrent pulmonary edema
- Renal failure
Diabetics and patients with high blood pressure, coronary or peripheral artery disease are at increased risk of developing renal artery stenosis, and, therefore, of requiring a renal artery stenting procedure.
The Renal Artery Stenting Procedure
The renal artery stenting procedure is designed to open the renal arteries when they have become blocked. It is performed during an angioplasty, a minimally invasive event during which a slender catheter is inserted through a small incision in the groin. Contrast dye is administered to improve visualization of the blood vessels involved. Once the catheter has been snaked to the diseased portion of the renal artery, a miniature balloon is inflated to enlarge the passageway and finally a stent is inserted to keep the affected blood vessel fully open for proper blood flow.
The procedure takes place within a catheterization laboratory under sedation. While the patient may experience discomfort, the stenting procedure is not painful, and patients generally experience improved blood flow and a restoration of kidney function immediately afterwards. Because there is some danger of recurrence of stenosis, particularly in older patients, women, smokers, and patients whose arteries are narrow to begin with, follow-up appointments with the treating physician are important. Patients may be prescribed anticoagulants to prevent future clots from forming and typically remain on medication to keep their blood pressure under control after the surgery.
Risks of Renal Artery Stenting
Although renal artery stenting is a relatively safe procedure, there are some inherent risks to any medical intervention. In this case, the risks include:
- Excessive bleeding or bruising at the site
- Blood clots
- Kidney damage or kidney failure
- Misplacement of the stent
- Adverse reaction to contrast dye
The most common complication of renal artery stenting is a recurrence of RAS which must be treated again.