report re: renal artery stenosis

[Jason]

Definition

Renal artery stenosis is a blockage or narrowing of the major arteries
that supply blood to the kidneys.

Description

Renal artery stenosis occurs when the flow of blood from the arteries
leading to the kidneys is constricted by tissue or artherosclerotic
plaque. This narrowing of the arteries diminishes the blood supply to the
kidneys, which can cause them to atrophy and may ultimately lead to kidney
failure. It may also cause renovascular hypertension,or high blood
pressure related to renal artery blockage.

Causes and symptoms

The two main causes of renal artery stenosis are artherosclerosis and
fibromuscular disease. Fibromuscular diseases such as fibromuscular
dysplasia cause growth of fibrous tissues on the arterial wall. Stenosis
may also occur when scar tissue forms in the renal artery after trauma to
the kidney.

Eventually, untreated renal arterial stenosis causes secondary
complications such as chronic kidney failure, which may be characterized
by anemia, edema, headaches, hypertension, lower back pain, and other
signs and symptoms.

Diagnosis

The high blood pressure that is sometimes associated with renal artery
stenosis may be the first sign that it is present, particularly if the
hypertension is not responding to standard treatment. Presence of a bruit,
a swooshing sound from the artery that indicates an obstruction, may be
heard through a stethoscope.

An arteriogram, an x-ray study of the arteries that uses a radiopaque
substance, or dye, to make the arteries visible under x ray, may also be
performed. This test is used with caution in patients with impaired kidney
function, as the contrast medium may cause further kidney damage.

Treatment

Treatment for renal artery stenosis is either surgical, pharmaceutical, or
with angioplasty or stenting. Angioplasty involves guiding a balloon
catheter down into the renal artery and inflating the balloon to clear the
blockage. A stent may be inserted into the artery to widen the opening.
Some patients may be candidates for surgical revascularization, which
involves restoring blood flow with an arterial bypass.