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Essentials of Diagnosis
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Severe pain of forefoot that is relieved by dependency
Pain or numbness of foot with walking
Ulceration or gangrene of foot or toes
Pallor when foot is elevated
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General Considerations
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Involves the tibial arteries of the lower leg and pedal arteries in the foot occur
Occurs primarily in patients with diabetes
There often is extensive calcification of the artery wall
First manifestation of leg ischemia is frequently an ischemic ulcer or foot gangrene rather than claudication
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Foot ischemia without attendant claudication
Ischemic rest pain or ulcers
May be first sign of severe vascular insufficiency
Termed "chronic limb-threatening ischemia"
Associated with highest rate of amputation
Characteristics of rest pain
Pedal pulses are absent
Dependent rubor with pallor on elevation
Skin of the foot is generally cool, atrophic, and hairless
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Differential Diagnosis
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Neuropathic dysesthesia
Cellulitis
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Digital subtraction angiography is the gold standard method to delineate the anatomy of the tibial-popliteal segment
Magnetic resonance angiography or CT angiography is less helpful for detection of lesions in this location due to the small vasculature and other technical issues related to image resolution
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Diagnostic Procedures
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Ankle-brachial index
May be quite low (in the range of 0.4 or lower)
May be falsely elevated when the arterial medial wall layer of the tibial arteries calcify (Mönckeberg medial calcific sclerosis) and are not compressible
Toe brachial index should be used if noncompressible ankle arteries are encountered
Blood flow studies (ankle-brachial index/toe-brachial index) are indicated if ulcerations appear and there is no significant healing within 2–3 weeks
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BYPASS AND ENDOVASCULAR TECHNIQUES
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Bypass with vein to the distal tibial arteries or foot effective in
These bypasses have good patency rates (70% at 3 years)
In nearly all series, limb preservation rates are much higher than patency rates
Endovascular treatment with plain balloon angioplasty is effective for short segment lesions
The technical failure and reocclusion rates increase drastically with long segment disease in multiple tibial arteries
Drug-coated balloons or stents have not been successful in the tibial vessels
Poor blood flow and a foot ulcer or nightly ischemic rest pain requires revascularization to avoid a major amputation
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