Page 130 - The Netter Collection of Medical Illustrations - Integumentary System_ Volume 4 ( PDFDrive )

Plate 4-45 Integumentary System

LOWER EXTREMITY VASCULAR VASCULAR INSUFFICIENCY IN DIABETES
INSUFFICIENCY

Vascular insufficiency of the lower extremity is a Dependent rubor,
common finding in the older population. Factors that absence of dorsalis
increase the risk of vascular disease include diabetes, pedis pulsation
obesity, smoking, hypertension, and hypercholesterol-
emia. Both the venous and the arterial systems may be
affected, and the signs and symptoms are unique to
each. The combination of venous and arterial insuffi-
ciency is commonly seen in older diabetic patients,
especially those who smoke. Abnormalities of the lym-
phatic system may cause findings similar to those of
venous insufficiency. Risk factors for lymphatic disease
include prior surgeries (e.g., inguinal lymph node dis-
section), radiotherapy, and idiopathic lymphedema. Diabetic ulcer
Clinical Findings: Venous insufficiency is a common
disease that has no racial or ethnic predilection. It has
been reported to be slightly more common in women.
Venous insufficiency eventually leads to venous stasis
and ulcerations. It has been estimated to be the cause
of more than 50% of lower extremity ulcerations, with
arterial insufficiency being the next most common
cause, and neuropathic causes and lymphedema
accounting for the remainder.
The first signs of venous insufficiency may be the
development of varicose veins or smaller dilated retic-
ular veins. As time progresses, venous stasis changes
are seen, including dry, pink to red, eczematous patches
with varying amounts of peripheral pitting edema. Red Valve
blood cells are extravasated into the dermis where,
over time, they break down and form hemosiderin
deposits, which appear as brown to reddish macules Healthy
and patches. Continued venous hypertension, stasis, vein
and swelling may eventually lead to a venous stasis
ulcer. These ulcers are most commonly present on the
medial malleolus region of the ankle but can occur
almost anywhere on the lower extremity. They are Extensive
usually nontender, but some can be exquisitely painful. gangrene
Arterial insufficiency is most often caused by athero-
sclerosis of the larger arteries of the lower extremity.
Patients often have coexisting risk factors including
older age, hypertension, smoking, diabetes, and hyper-
cholesterolemia. Arterial ulcers are slightly more
common in men, and there is no racial predilection.
The clinical presenting signs are often dependent
rubor, claudication, and rest pain. Physical examination
confirms the absence of peripheral pulses in the dorsal
pedal and posterior tibial arteries. At this point, the
patient is at high risk for arterial ulcerations and subse-
quent gangrene. Surgical intervention is the only viable
means of treatment.
Pathogenesis: Venous drainage of the lower extrem-
ity is accomplished via the superficial and deep systems Ulcer with lymphedema
of veins that are connected through horizontally Gangrene of toe and stasis dermatitis
arranged communicating vessels. These veins contain skin changes
one-way bicuspid valves that prevent backflow and
work with the action of muscle contraction to force the
venous flow in a superior direction, eventually to empty
into the inferior vena cava. The flow of venous blood hypertension occurs, the patient is at risk for develop- Histological evaluation of venous ulcerations shows a
toward the vena cava is the primary responsibility of the ment of venous stasis and venous ulcerations. nonspecific ulcer, edema, proliferation of superficial
leg muscles, especially the calf muscle. Patients with Arterial insufficiency is caused by a slow narrowing dermal vessels, and extravasated red blood cells with a
sedentary lifestyles are at higher risk for venous insuf- of the arteries due to cholesterol plaque. This narrow- varying amount of hemosiderin deposition.
ficiency. During ambulation, the venous pressure nor- ing restricts the amount of blood flow to the tissue. Treatment: Venous insufficiency is treated with a
mally decreases as the blood flow is increased toward Once the flow is decreased to less than the requirement combination of compression and leg elevation. Losing
the vena cava. If an abnormality exists and this does not needed for muscle and normal physiological function- weight and increasing the activity level may also help.
occur, venous hypertension ensues. Congenital absence ing, symptoms arise. Arterial insufficiency is best treated surgically with stent
of the venous valves, incompetent valves, and a history Histology: Biopsies should not be performed in cases placement or arterial bypass of the narrowed artery.
of deep venous thrombosis are just three of the poten- of arterial insufficiency, because they lead to ulcer- Pentoxifylline has also been used, with variable success,
tial reasons for venous insufficiency. Once venous ations, infections, and, most likely, emergent surgery. in early disease.

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