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Peripheral Arterial Disease
OVERVIEW
Peripheral Arterial Disease (PAD) is a condition
which affects approximately 12 million people in the
United States. The disease results from the
accumulation of plaque in arteries, most commonly
occurring in the pelvis and legs. PAD occurs when
plaque buildup causes a narrowing of the artery,
constricting normal blood flow to the body’s tissue
and organs. If left untreated, PAD increases the
risk of heart attack, stroke, amputation and death.
In fact, whether they are symptomatic or not,
patients with PAD face a five-year mortality rate of
30%. An estimated 12 million people in the U.S. have
peripheral arterial disease (PAD). However, PAD is
often undiagnosed or misdiagnosed because patients
are either asymptomatic or dismiss their symptoms as
part of the normal aging process.
SYMPTOMS AND DIAGNOSIS
- Symptoms of PAD can include, but are not limited to
the following:
- Claudication: dull, cramping pain in the hips,
thighs, calves or buttocks
- Numbness or tingling in the leg, foot or toes
- Changes in skin temperature: cold to the touch
- Changes in skin color: bluish or reddish coloration
Impotence
- Sores or infections that do not heal
- Weakness in legs or arms
- If a patient has symptoms associated with PAD,
several tests can be performed to make a diagnosis.
An ankle brachial index (ABI) is used to measure the
rate of blood pressure in the ankle to that in the
arm. A lower pressure in the ankle may indicate PAD.
This is a simple, non-invasive test, which can be
done in the doctor's office. Another non-invasive
test called a Doppler Ultrasound, uses sound waves
to measure blood flow in a vessel and can determine
if there is a blockage.
- To make a final assessment, angiography is
performed. This minimally invasive procedure
involves injecting a dye into the arteries and
reviewing the area by X-Ray. Typically, the
physician can see the blockage on the angiogram
images.
RISK FACTORS
Researchers have identified certain risk factors,
which can contribute to the development of
peripheral arterial disease. Key risk factors
include:
- Age - The incidence of PAD increases with age, and
affects approximately 20% of the U.S. population
over 70. Due to an aging population, the estimated
number of people with PAD is expected to grow to
over 17 million in 2010 and over 22 million in
2020.1
- Smoking - Smokers have three times the rate of PAD
as non-smokers and are diagnosed on average 10 years
earlier.2
- Diabetes - In 2002, there were 18 million U.S.
adults with diabetes, with approximately 1.3 million
new cases of diabetes diagnosed each year.3 The
prevalence of PAD is 20% higher in the diabetic
population. It is estimated that over 23% of
patients with diabetes between ages 55 – 74 have
PAD.4
- Coronary artery disease - An estimated 40% of
patients with CAD have PAD.5
Additional risk factors include hypertension, high
cholesterol, obesity and family history.
CRITICAL LIMB ISCHEMIA
If left untreated, PAD can progress to critical limb
ischemia (CLI), which occurs when there is not
enough oxygenated blood being delivered to the leg
to keep the tissue alive. An estimated 750,000
people in theUnited States suffer from CLI, which
occurs when symptoms of PAD—including pain,
non-healing wounds, tissue loss or gangrene—become
more severe.1
When CLI develops, it can lead to constant pain and
even amputation of toes, feet and/or part of the
leg. Within one year of the onset of CLI, 25% of
patients will die and another 25% will require major
amputation. Last year, over 150,000 amputations were
performed in the U.S. and Europe, with a 40%
mortality rate at two years post-amputation.
TREATMENT
A number of options are available for treating PVD,
including surgery and non-surgical treatments, such
as angioplasty and vascular stent placement.
Vascular surgery: In the past, surgery was the only
treatment available for PVD and, in some cases,
surgery may still be needed. When surgery is
required, the surgeon implants a new vessel (a
natural or synthetic vascular graft) that allows
blood to bypass the obstruction. The procedure
usually requires one or more incision to perform.
Angioplasty: In recent years, a new non-surgical
procedure called percutaneous transluminal
angioplasty (PTA) has been performed on patients
with PVD. During angioplasty, a specially trained
doctor inflates a tiny balloon inside the vessel,
compressing the plaque against the vessel walls. The
balloon then deflates and is withdrawn from the
vessel. This procedure is performed entirely within
the vessel through a small puncture in the skin.
However, because angioplasty does not always restore
blood flow effectively, the doctor may recommend
placement of an intravascular stent in the vessel.
Intravascular Stent: An intravascular stent is a
small stainless steel tube that is introduced into
the blocked artery. The stent is then gently
expanded to open the vessel, restore blood flow, and
relieve symptoms. The stent remains in the vessel as
a permanent implant. The stent is placed on the
balloon catheter and directed to the blocked area of
the vessel. Once the balloon and stent are in the
correct position, the balloon is inflated, causing
the stent to open. One or more stents may be
expanded in the vessel. The stent will remain in
place permanently, keeping the vessel open. The
healthy lining of the vessel will slowly grow over
the stent, permanently incorporating it into the
vessel wall. The stent will not limit daily
activities in any way, and spent patients can almost
always return to their normal activities. Patients
who have had a vascular stent implant should tell
this to any doctor who treats them in the future.
Atherectomy: Why some arteries treated with stents
and angioplasty re-close quickly while others stay
open indefinitely remains to be completely
understood. The SilverHawk™Plaque
Excision System is a device used to remove plaque
that commonly blocks arteries and interrupts blood
flow. Unlike stenting and other methods of opening
the artery, the SilverHawk removes the source of the
problem – plaque build-up – instead of simply
compressing it against the vessel wall. Atherectomy
can also be achieved by using a cool laser (Spectranetics) that vaporizes the
blockages restoring blood flow.
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