Peripheral
Arterial Disease
Peripheral
arterial disease (PAD) is most commonly
caused by atherosclerosis
or hardening
of
the arteries.
This common affliction can go unnoticed for many years
because it usually progresses slowly and onset of
symptoms is gradual until it is finally diagnosed. The
presence of arterial
insufficiency produces very
specific symptoms and therefore diagnosis can often be
made by a careful history and physical examination.
Simply feeling for pulses can alert the physician to the
presence of any significant artery blockages. Very often
testing may be indicated to determine the severity and
pattern of the disease and establish unequivocally if the
symptoms you experience are due to PAD. Testing can be
done non-invasively and consists of a variety of
techniques that can measure the pressure and volume of
blood in the affected limb. If this is abnormal, a
complete overview of the circulation in the legs is most
often made with ultrasound, a relatively inexpensive,
completely safe and noninvasive technique that obtains
pictures of the vessels and information about the blood
flow in real time. No other technique provides both the
anatomic and physiologic information which is of prime
importance in PAD.
How the lower extremity artery system
works -
The
arterial system is
a series of branching vessels all originating from the
heart—the central pump of the body. Similar to tree
branches, the arteries become smaller and smaller as they
extend to the periphery of the body. the aorta is the main
artery that arises from the heart and gives rise to all
other arteries. The abdominial aorta branches into the iliac
arteries at the umbilicus or belly button. These in turn
branch again and again until vessels course all the away to
the abdomen.
ATHEROSCLEROSIS
-
Normally the inner wall of an
artery called the intima is smooth and
elastic, allowing blood to flow freely. In vessels affected
by atherosclerosis, the intima becomes thickened
and rough by a build up cholesterol or fatty materials. This
build up, much like rust in a pipe, is called plaque. As
this plaque increases, it obstructs the opening or
lumen of the
blood vessel and may alter or limit the flow of blood. If
the artery is severely narrowed, the amount of blood getting
past can be so limited, that various symptoms can result.
However, as long as this is a gradual process, the body is
often very good at developing alternative pathways for blood
flow called collaterals.
SYMPTOMS -
-
Claudication
- leg pain with
exercise is the classical symptom for lack of
blood flow to the legs. An ache or cramp develops
in the calf, thigh, or buttocks when the
muscle cannot get enough oxygen, Resting,
even for a short time, will allow the blood
supply to “catch up” with the demand
and symptoms subside.
-
Rest
pain - severe and steady aching
or pain, usually in the toes, heel, or foot,
this suggests severe arterial disease.
-
Gangrene
- blood supply
is insufficient to support the tissues and they
begin to die ( tissue
necrosis).
There are
other reasons why a person may experience leg pain with
exertion or even at rest - commonly neuropathy or a nerve
compression (neurospinal) syndrome. The testing equipment at
QVI is well suited to determine with a high degree of
certainty if pain is from a vascular cause
(vasculogenic) or not.
DIAGNOSIS -
is typically done with a
combination of
physiologic testing and duplex
ultrasound (click for more
on these testing procedures.) This non-invasive test can
determine if disease is present, its severity, and if it is a
likely source of your symptoms. We can also provide an overview
of the arterial tree showing the pattern of disease. For
example, it is important to know specifically where the disease
is, if there is an isolated area of narrowing or is there
diffuse disease throughout long segments, and if a vessel is
severely narrowed of completely occluded. This information
allows your physician to make specific recommendations as to
the best way to treat your disease.
These
ultrasound images show tibial arteries in the calf. The
vessel on the left depicted in gray scale with the Doppler
information displayed in color is widely patent and normal.
In contrast, the vessel on the right shows a severe
narrowing with the resultant flow disturbance.
The
vessel on the left shows a flow limiting narrowing in the
popliteal artery behind the knee - the main blood supply to
the lower leg. The popliteal artery on the right reveals a
large aneurysm with thrombus inside. While peripheral artery
aneuryms rarely rupture, they are potentially quite
dangerous if they shower this thrombus to the lower
leg.
TREATMENT
-
-
Modify risk
factors - Patients with disease can
dramatically lessen the likelihood of the narrowing
becoming worse. Stop
smoking, control blood pressure, blood
sugar, and cholesterol levels, maintain proper
weight and diet.
-
Exercise - Most
importantly, a regular exercise regimen can build
collaterals and actually reduce the severity of the
symptoms. See also our section on Exercise by clicking
here!
-
How far? Experience
shows walking a loop is a useful method. Choose a
distance where you get the pain a few minutes before
you finish. Remember, you must walk some distance with
the pain to get maximum benefit. Then gradually try to
lengthen the loop. Regularly walk short or moderate
distances, instead of longer distances sporadically.
Regularity is key!
-
Follow-up - This can
usually be done clinically. “Are you walking farther
without pain?” If necessary, the severity of the plaque
buildup can be followed by ultrasound and / or
physiologic testing to determine if there is any
progression of disease.
-
Medicine - While
medicine will generally not lessen the plaque, there
are several medications that may be prescribed to aid
in modifying risk factors or reduce symptoms.
-
Endovascular Intervention
- There are a multitude of “minimally
invasive” options to treat blockages. Most common is
balloon angioplasty with a stent inserted to hold the
artery open.
-
Surgery - If blockages
are too extensive, bypass surgery can be done to get
blood to the affected area. A vein from the leg or arm
or a synthetic tube can be used to bypass the blocked
artery. This is usually done for rest pain or
gangrene.
Here is a great link from the Society of
Vascular Surgery that thoroughly outlines the all the options -
http://www.vascularweb.org/_CONTRIBUTION_PAGES/Patient_Information/NorthPoint/Angioplasty_and_Stenting.html
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