P1: SBT
0521779407-04a CUNY1086/Karliner 0 521 77940 7 June 4, 2007 20:48
Atherosclerotic Occlusive Disease 181■Elevation on pallor
➣Cadaveric pallor on elevating foot 3 feet with patient supine
■Ischemic changes in limb
➣Muscle atrophy, shiny skin
➣Loss of secondary skin structures (hair follicles)
■Ankle/brachial index:
➣Ratio of blood pressure at ankle to that in arm. Put cuff on upper
arm, Doppler (not palpate) the radial pulse and inflate cuff until
Doppler signal is gone. Repeat at each ankle with cuff immedi-
ately above ankle.
➣Normal >0.9
➣Claudication 0.3–0.9
➣Limb Threat < 0.3
➣Falsely elevated (and not helpful) in diabetics with severely cal-
cified non-compressible vesselstests
Laboratory
■Blood
➣Hypercoaguable evaluation for patients less than 50 years of age
➣Lipid profileNon-Invasive Vascular Studies
■Carotid Duplex (ultrasound imaging+Doppler velocity analysis)
➣Determines extent and severity of extracranial carotid stenosis
■Captopril-renal scan
➣Useful as screening test for functional significance of renal artery
stenosis
➣Can be false-negative in bilateral disease
■Lower extremity segmental pressure and waveforms
➣Multiple cuffs on lower extremity
➣Defines extent and level of occlusive disease
➣Pressures and ratios not useful in diabetics with severely calcified
vessels
Pulse waveforms and toe pressures useful in diabetics
➣Magnetic resonance angiography (MRA)
➣Replaces angiography for diagnosis in many vascular beds
(mesenteric, carotid)Invasive Studies
■Cerebral angiography