ESSENTIALS OF DIAGNOSIS
Severe pain of the forefoot that is relieved by dependency.
Pain or numbness of the foot with walking.
Ulceration or gangrene of the foot or toes.
Pallor when the foot is elevated.
Occlusive processes of the tibial arteries of the lower leg and pedal arteries in the foot occur primarily in patients with diabetes (eFigure 12–3). There often is extensive calcification of the artery wall. While claudication is a common initial symptom of ischemia, it may not be present. The first manifestation of ischemia is frequently an ulcer or gangrene rather than claudication.
Common sites of stenosis and occlusion of the visceral and peripheral arterial systems. (Reproduced, with permission, from Way LW [editor]. Current Surgical Diagnosis & Treatment, 10th ed. Originally published by Appleton & Lange. Copyright © 1994 by The McGraw-Hill Companies, Inc.)
Unless there are concomitant lesions in the aortoiliac or femoral/superficial femoral artery segments, claudication may not occur. The gastrocnemius and soleus muscles may be supplied from collateral vessels from the popliteal artery; therefore, foot ischemia without attendant claudication may be the first sign of severe vascular insufficiency due to isolated tibial artery disease. The presence of ischemic rest pain or ulcers is termed critical limb ischemia and is associated with the highest rate of amputation. Classically, ischemic rest pain is confined to the dorsum of the foot and is relieved with dependency: the pain does not occur with standing, sitting or dangling the leg over the edge of the bed. It is severe and burning in character, and because it is present only when recumbent, it may awaken the patient from sleep. Because of the high incidence of neuropathy in these patients, it is important to differentiate rest pain from diabetic neuropathic dysesthesia. Leg night cramps, which are not a purely ischemic phenomenon, cause pain in the leg rather than the foot and should not be confused with ischemic rest pain.
On examination, depending on whether associated proximal disease is present, there may or may not be femoral and popliteal pulses, but the pedal pulses will be absent. Dependent rubor may be prominent with pallor on elevation. The skin of the foot is generally cool, atrophic, and hairless.
B. Doppler and Vascular Findings
The ABI may be quite low (in the range of 0.4 or lower). ABIs, however, may be falsely elevated when the medial layer of the arterial wall of the tibial arteries calcify (Mönckeberg medial calcific sclerosis) and are not compressible. Toe-brachial indexes should be used if noncompressible ankle arteries are encountered.
Digital subtraction angiography is the gold standard ...