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per dL in patients with symptomatic vascular
disease.
3. Tobacco is directly toxic to the vascular
endothelium and worsens atherosclerosis. All
patients must abstain from tobacco use.
B. Antiplatelet agents
1. Aspirin should be considered for use in any
patient with coronary artery disease,
cerebrovascular disease or PAOD.
2. Clopidogrel (Plavix), 75 mg qd, or ticlopidine
(Ticlid), 250 mg bid with meals, should be
considered in patients who are intolerant of
aspirin therapy. Clopidogrel and ticlopidine are
platelet inhibitors; however, clopidogrel has a
lower risk of neutropenia.
C. Exercise. Walking improves the symptoms of
claudication. Patients should walk at least three
times per week for at least 30 minutes at each
session. Near-maximal claudication pain (absolute
claudication distance) should be the resting point,
and the patient should follow the program for at
least six months.
D. Medication
1. Cilostazol (Pletal), 100 mg bid, is a
phosphodiesterase inhibitor that suppresses
platelet aggregation and acts as a direct arterial
vasodilator. Cilostazol results in a 35 percent
increase in the distance before claudication and
a 41 percent increase in absolute claudication
distance.
2. Pentoxifylline (Trental), 400 mg tid with meals,
provides small improvements in the initial
claudication distance and absolute claudication
distance.
E. Operative and endovascular procedures
1. Most patients with claudication respond to
conservative therapy. Surgery is reserved for
patients with rest pain or tissue loss. Patients
who have intermittent calf claudication alone are
not surgical candidates unless the claudication
severely limits their lifestyle or occupational
functioning.
2. Patients with rest pain, tissue loss as a result of
gangrene, or non-healing ulcers with an ABI less
than 0.6 are surgical candidates.
3. Percutaneous transluminal angioplasty has a
greater than 90% success rate in the treatment
of short-segment aortoiliac occlusive disease,
and these results may be improved with the
placement of an intra-arterial stent. However,
five-year patency rates are only 40-60%.
4. Surgical bypass therapy is an effective
treatment for claudication; however, it is
associated with 5% morbidity and mortality rates.
Aortobifemoral grafting has a 90% 5-year
patency rate. Aortoiliac, femoral-femoral
crossover, and reversed and in-situ saphenous
vein bypass grafting from the common femoral to
the popliteal artery have 60-70% 5-year patency
rates. A synthetic polytetrafluoroethylene graft
( PT F E) i s i ndi cated fo r above k n e e
femoral-popliteal bypass, and it has a 50% 5
year patency rate.
5. Axillofemoral bypass is useful for high risk,
elderly patients who are unable to tolerate an
aortic procedure.
F. Management of the acutely threatened limb. An
acutely occluded artery can cause limb loss within
hours. The patient will complain of sudden onset of
severe unrelenting rest pain. Atrial fibrillation often
may cause acute embolic arterial occlusion. These
patients require emergency surgical evaluation and
immediate heparinization.
Abdominal Aortic Aneurysms
S.E. Wilson, MD
Abdominal aortic aneurysms (AAAs) are the most
common type of arterial aneurysm. Approximately 5% of
people older than 60 years develop an abdominal aortic
aneurysm, and the male-female ratio is 3:1. Other risk
factors include smoking, hypertension, and a family
history of an aneurysm. Abdominal aortic aneurysms are
caused atherosclerosis in 90% of patients; 5% of
aneurysms are inflammatory.
I. Clinical evaluation
A. Abdominal aortic aneurysms are usually
asymptomatic. Aneurysm expansion or rupture
may cause severe back, flank, or abdominal pain
and shock. Distal embolization, thrombosis, and
duodenal or ureteral compression can produce
symptoms.
B. Physical examination. Almost all AAAs greater
than 5 cm are palpable as a pulsatile mass at or
above the umbilicus. Abdominal aortic aneurysms
range from 3 to 15 cm in diameter.
II. Laboratory evaluation. Complete blood count,
electrolytes and creatinine, blood urea nitrogen,
coagulation studies, blood type and cross-matching,
and urinalysis should be obtained.
III. Radiologic evaluation
A. Abdominal cross-table lateral films allow for
estimation of aneurysm diameter.
B. Ultrasonography and computed tomographic
(CT) scanning demonstrate AAAs with an
accuracy of 95% and 100%, respectively.
IV.Elective management of abdominal aortic
aneurysms
A. Small aneurysms can be followed using ultrasound
or CT scan every 6 months.
B. Indications for repair include symptomatic
aneurysms of any size, aneurysms exceeding 5.0
cm, those increasing in diameter by more than 0.5
cm per year, and saccular aneurysms.
C. Preoperative management includes optimizing
cardiopulmonary function and placement of a
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