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By late middle age 5% of men and women have developed
peripheral arterial disease, and within 5 years one quarter of these
will develop pain at rest, ulceration, and gangrene (critical limb ischemia).1 Physicians
practicing in the specialty of pain medicine need to be familiar
with the causes and management of pain due to peripheral vascular
disease because it has a high prevalence and appropriate management
can significantly improve the quality of life for these patients. The
pain physician may also be able to significantly improve life expectancy
because one half of the patients with symptomatic peripheral vascular
disease also have coronary and/or carotid artery disease,
and many will not be receiving recommended secondary and tertiary
preventive therapy. This chapter outlines the disease conditions
and treatments for pain associated with peripheral vascular disease.2
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Pain similar to that experienced with peripheral vascular disease
can be experimentally produced using a sustained tourniquet inflation
on an extremity. In experimental studies, as time passes, tissue
oxygenation levels fall, metabolic byproducts accumulate, reactive
cellular agents are released, nociceptive signals entering the central
nervous system increase, and patients report increasing pain intensity.
The affective descriptors for this pain may differ and be more difficult to
tolerate than pain produced by other experimental modalities. Patients
with peripheral vascular disease experience this type of pain but
without the ability to restore blood flow by releasing the tourniquet.
Effective management of this pain can make a significant difference
in quality of life for these patients.
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Arterial insufficiency is most commonly the result of occlusive
diseases with atheroma formation (arteriosclerosis obliterans),
but less commonly it occurs in thromboangiitis obliterans (Buerger disease),
Raynaud syndrome, diabetic arteritis, and arteritis associated with
collagen disease. Other diseases with vascular-related causes such
as migraine and cluster headache are discussed elsewhere (Chapter 20).
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Atheroma and
Its Consequences: Arteriosclerosis
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The role of lipids was suggested with the early appearance of
fatty streaks in young soldiers during emergency surgery and at
autopsy in the 1970s. The role of lipids distinguishes arteriosclerosis
from other arterial disease. Primary and secondary prevention strategies
are available to reduce the incidence and/or aggressively
treat the known risk factors of hypercholesterolemia, hypertension,
cigarette smoking, and poor control of diabetes. As the disease
progresses, plaque formation tends to occur at bifurcations in large-
and medium-sized arteries, where turbulence, alteration of laminar
flow, and shear stress may provoke an endothelial and/or
vascular smooth muscle response. Arteriosclerosis is a dynamic process
that involves vascular and inflammatory tissue responses with decreased
release of nitric oxide and other protective secretions, increased
release of cytokines by inflammatory cells responding to exposed
matrix, and release of growth factors from the endothelium, as well
as platelet activation. Arteries may initially respond to this process with
an increase in size, but this arterial remodeling may not be sustained
in the face of ongoing plaque accumulation. Although a full discussion
of the process ...