[Noninvasive methods in the diagnosis of macro- and microangiopathy of peripherial and carotid arteries].

PURPOSE

Indications and diagnostic value of the most important noninvasive procedures for the diagnosis of peripheral arterial disease and diseases of the supraaortic arteries are reviewed in this article with particular emphasis on cardiologic questions.

PERIPHERAL ARTERIAL DISEASE

As compared to coronary artery disease, peripheral arterial disease has long been addressed as being negligible in number and importance, a view that had to be reassessed in recent years. The prevalence of claudication and critical leg ischemia has increased. Earlier diagnosis and specific therapeutic regimens will be able to prevent or at least slow progression of the disease and, thereby, major amputation. The patient's history and physical examination in addition to measurement of the ankle-brachial index (ABI; determined by dividing the systolic pressure measured by Doppler ultrasonography of the A. dorsalis pedis or A. tibialis posterior by that of the A. brachialis) usually allows for the diagnosis of peripheral arterial disease (ABI < 0.9). If in doubt (ABI > 0.9, but presence of typical claudication), a treadmill test or additional tests such as pressure-pulse recording (mechanical oscillography), toe pressure measurements, or duplex ultrasonography should be performed. When peripheral arterial disease has been diagnosed, duplex ultrasonography or treadmill testing aids in planning additional diagnostic procedures and the adequate therapeutic regimen. Transcutaneous oxymetry is of prognostic value in assessing the tendency of wound healing in distal limb ulceration and can distinguish between critical limb ischemia and complicated claudication. Thermography is used to document functional and organic peripheral arterial occlusions and capillaroscopy to directly view nail fold capillaries in order to distinguish between primary and secondary Raynaud's phenomenon. Noninvasive radiologic techniques in the diagnosis of peripheral arterial disease are also discussed in this journal.

SUPRAAORTIC ARTERIES

Noninvasive diagnostic procedures in assessing disease of the supraaortic arteries include history-taking, physical examination, continuous-wave-(cw-)Doppler and color-coded ultrasonography. Cw-Doppler ultrasonography is still widely used and sufficient in diagnosing moderate to severe stenosis or occlusion of the carotid artery. B-mode and color-coded ultrasonography has several advantages over cw-Doppler ultrasonography through direct visualization of the vascular membrane, perivascular structures, and intravascular blood flow. Carotid stenosis < 50% and plaque morphology can be assessed, inflammatory processes, aneurysms, and dissections diagnosed. Increase in intima-media thickness and echolucent plaques are associated with cerebral ischemic events and can be diagnosed via duplex sonography. These findings have great implications in the consultation of patients with atherogenic risk factors.