Peripheral Arterial Occlusive Disease of the Upper and Lower Extremities
Diagnosis and staging
An ankle-brachial index of 0.90 or less is abnormal; 0.91–1.0 is borderline and warrants exercise testing. Claudication corresponds to Rutherford 1–3 or Fontaine II. Chronic limb-threatening ischemia (CLTI) means rest pain, ulceration, or gangrene present more than two weeks with objective hypoperfusion (ankle pressure under 50–70 mmHg, toe pressure under 30 mmHg, or transcutaneous oxygen under 10 mmHg). Traps: an incompressible index above 1.3 in diabetes or renal failure hides disease - use toe pressures; and a neuropathic diabetic ulcer is not automatically ischemic.
Treatment
Everyone needs smoking cessation, a statin, antiplatelet therapy, and exercise. Claudication responds to supervised exercise and cilostazol (contraindicated in heart failure); revascularize when lifestyle remains limited. Iliac lesions do well with angioplasty and stenting; femoropopliteal disease has higher restenosis, and infrapopliteal disease is best served by vein bypass. BASIL favored bypass first when a usable vein exists and life expectancy exceeds two years.
Nonatherosclerotic traps
Popliteal entrapment in a young athlete with exertional calf pain; adventitial cystic disease with a scimitar sign; Buerger disease in a young heavy smoker with distal skip lesions and corkscrew collaterals, where only smoking cessation durably helps and proximal bypass fails. Blue toe syndrome suggests atheroembolism from a proximal iliac aneurysm. Upper-limb ischemia is more often vasospastic, embolic, or thoracic outlet related than atherosclerotic.
Rule of thumb: an index below 0.4 correlates with rest pain, and below 0.2 with gangrene and imminent limb loss.