Renal artery stenosis is a disease where the arteries responsible for transporting blood to one or both of the kidneys become narrowed. The two leading causes of renal artery stenosis include atherosclerosis and fibromuscular dysplasia. Atherosclerosis causes the arteries around the body to harden and narrow because of plaque buildup, while fibromuscular dysplasia causes the arteries to become narrowed from abnormal tissue overgrowth in the artery walls. When renal artery stenosis occurs, the body can sense an inadequate amount of blood is reaching the kidneys. The body then mistakenly believes the blood pressure throughout the body is too low. The body responds to this by the release of certain hormones that increase blood pressure. Long-term hypertension caused by worsening renal artery stenosis can cause kidney failure.
Medications To Relax Blood Vessels
The use of medications to relax blood vessels is a common component in the treatment of renal artery stenosis because they lower blood pressure. One significant concern about renal artery stenosis is how it causes long-term hypertension. High blood pressure over time can result in numerous life-threatening conditions and diseases when it is not adequately treated. For most renal artery stenosis patients, a combination of two or more medications is used to relax the blood vessels to decrease blood pressure. Angiotensin II receptor blockers (ARBs) and angiotensin-converting enzyme (ACE) inhibitors work to help stop the production or action of a naturally occurring chemical that causes the blood vessels to narrow called angiotensin II. Medications that dilate the blood vessels and slow the heart rate are called beta blockers and alpha-beta blockers. Calcium channel blockers help relax the blood vessels by acting on the calcium channels responsible for regulating the heartbeat. It is common for renal artery stenosis patients to be put on one or more of these drugs on a long-term basis.
Diuretics or medications that help the body rid itself of excess water and salt through the urinary tract are often used to treat individuals with renal artery stenosis. Diuretics remove fluid from the blood and send it through the kidneys for elimination. This elimination occurs because diuretics increase the body's salt output, and the salt takes extra fluids with it when it exits the body. This mechanism reduces the amount of total fluid flowing through the blood vessels. The reduction in total fluid causes a decrease in pressure inside of the blood vessels. Elimination of extra fluids and salt will keep the blood pressure throughout the body low, including in the renal arteries. Diuretics also allow the heart to pump blood more efficiently throughout the body, including pumping blood to the kidneys. Diuretics on their own are often not enough to treat hypertension precipitated from renal artery stenosis, and they are usually combined with other medications like ACE inhibitors that work to dilate the blood vessels.
Renal Artery Bypass Surgery
Some individuals with severe cases of renal artery stenosis may need renal bypass surgery to treat the disease effectively. Usually, a renal angioplasty and stent placement is the next step taken when diet changes and medications prove to be ineffective. However, some renal artery stenosis patients have a renal artery that is too obstructed or blocked to undergo the placement of a stent. A renal artery bypass surgery allows the blood to redirect around the obstruction in one or more of the renal arteries. The bypass can be produced using a healthy vein from another region of the patient's body, or it can be made out of a synthetic artery. During the procedure, the surgeon identifies and removes a healthy vein from another part of the body (if they are not using a synthetic vein). The surgeon then uses stitches to connect one end of the synthetic or healthy vein to the aorta, femoral artery, or a healthy artery in the abdomen. The other end is then attached to the renal artery between the kidney and the obstruction. This mechanism allows for blood to flow freely around the blockage of the renal artery. Recovery for renal artery bypass surgery is between two and four weeks. However, the result is permanent and known to be very successful at treating renal artery stenosis.
Renal Angioplasty And Stenting
When diet changes and medications are not effective at treating renal artery stenosis, a procedure called renal angioplasty and stenting may be recommended. This surgical procedure lowers blood pressure, increases blood flow to the kidneys, and prevents further complications such as organ damage. Renal angioplasty and stent placement involve the use of a long flexible tube called a catheter, a small balloon, and a stent or mesh wire tube. A small incision is made in the patient's thigh, and the surgeon guides the catheter from the femoral artery to the affected renal artery. A small balloon at the end of the catheter is then inflated, and the plaque or excess tissue are pushed against the walls of the artery. This mechanism effectively widens the artery. The surgeon then places the wire mesh tube or stent inside of the widened artery to hold its expanded position. The balloon is then deflated, and the catheter and balloon are removed. The stent stays in place permanently to allow for better blood flow to the kidneys. Renal angioplasty and stenting placement is a minimally invasive procedure, and it has a significantly quicker recovery time than other traditional open surgical procedures.
Maintain A Healthy Diet
Mild cases of renal stenosis may be able to be treated with a diet change. When an individual can maintain a healthy diet, they can keep their blood pressure low enough to avoid other interventions. Because obesity can compound the dangerous effects of high blood pressure, it is vital for individuals to eat a healthy diet to maintain a healthy weight. Both alcoholic beverages and consumption of any tobacco should be avoided.
Less than 2,300 milligrams of sodium should be consumed each day. Foods containing less than five percent of the daily recommended value of sodium are better choices than those containing more. Any food or drink that exceeds twenty percent of the recommended daily value should also be avoided. Canned foods, fast foods, processed foods, and lunch meats should be avoided. Seasonings free of salt should be used instead of options including salt. In addition, foods high in potassium, fiber, and magnesium can help with blood pressure control. Sugary foods and sweetened beverages should be eliminated. A diet to help lower blood pressure may be combined with one or more other renal artery stenosis treatment methods.