Renal Artery Stenosis

The renal arteries are the blood vessels that carry blood to the kidneys. Renal artery stenosis occurs when one or more of these vessels become narrowed. This can lead to decreased blood flow to your child’s kidney or kidneys, as well as increased blood pressure, a condition known as renovascular hypertension.

What causes renal artery stenosis?

In most children with renal artery stenosis, the affected renal artery is already narrow at birth. Other causes include vasculitis (inflammation of the blood vessels) and the genetic condition neurofibromatosis, in which tumors form from nerve tissue. Renal artery stenosis is also associated with midaortic syndrome, a rare condition in which part of the aorta (the heart’s largest blood vessel) that runs through the chest and abdomen becomes narrow. This can lead to lower blood flow to other parts of the body, including the kidneys.

What are the symptoms of renal artery stenosis?

The main symptom of renal artery stenosis is high blood pressure, often severe.

Left untreated, it can also lead to complications, such as:

• seizures
• stroke
• kidney failure
• slow weight gain (failure to thrive)

How is renal artery stenosis diagnosed?

Clinicians use a variety of approaches to diagnose renal artery stenosis in children. In addition to reviewing your child’s medical history and performing a physical exam, they may recommend imaging tests including:

• ultrasound, which uses high-frequency sound waves and their echoes to make cross-sectional images of the inside of your child's body
• computer tomography (CT) angiography scan, which uses a special contrast solution (dye) and radiation to measure the size of the organs and blood vessels in the body
• magnetic resonance angiography, which uses a special contrast solution (dye) and imaging technology to map the blood vessels in your child’s body
• direct angiography, in which dye is injected through a catheter (tube) in the child’s aorta or femoral artery, and the flow and size of the vessels is measured

How is renal artery stenosis treated?

Treatment for renal artery stenosis depends on the severity of the condition.

Initially, clinicians will prescribe medication to lower your child’s blood pressure. Sometimes, more than one medication is needed. If medications are not successful, or if the narrowed blood vessel is compromising the health of one or both kidneys, other treatment approaches may be used.

In some cases, the narrow vessel can be dilated during a procedure called an angioplasty or opened with a stent. In other cases, your child may need surgery to improve blood flow to the kidney or kidneys.

How we care for renal artery stenosis

The clinicians in the Midaortic Syndrome and Renovascular Hypertension Center at Boston Children’s Hospital diagnose and treat children with renal artery stenosis. Our team of specialists draws on expertise from nephrology, interventional radiology, cardiology, and vascular surgery to care for children with this condition. We work together to determine the best approach for diagnosis and treatment for your child. Often, this involves long-term follow-up to ensure the best outcomes.