Limitations of noninvasive evaluation of carotid occlusive disease
J. B. Herrmann, M. Korgaonkar and B. S. Cutler
A series of 32 patients examined by two different noninvasive techniques in
two different laboratories and by cerebral angiography were retrospectively
studied. Significant differences in ophthalmic artery pressures as measured
by oculopneumoplethysmography (OPPG), and significant delays in ocular
pulse arrival time combined with characteristic recorded bruits as
determined by oculoplethysmography/carotid phonoangiography (OPG/CPA) were
considered as an index of carotid stenosis. Cerebral angiography was
performed on all 32 patients to confirm or refute the diagnosis suggested
by noninvasive testing. In this selected group of patients with difficult
diagnostic problems, only 67% of significant (greater than 50% diameter)
stenoses were detected by OPPG, and only 58% by OPG/CPA. Combining OPPG and
OPG/CPA increased the probability of detecting a greater than 50% diameter
stenosis to 92%.
