To investigate the hemodynamics and clinical presentation of common
carotid artery occlusion (CCAO), we reviewed 6,415 patients with
suspected carotid artery disease in whom a color Duplex imaging (CDI)
examination was performed. According to distal vessel patency, the
following CDI classification of CCAO was adopted: type I (patent both
distal vessels); type II (isolated patency of external carotid artery);
type III (isolated patency of internal carotid artery); and type IV
(both distal vessels occluded). Thirty-five (0.5%) cases met the CDI
criteria for CCAO. Twenty-nine of those (83%) had at least one patent
distal vessel. Ten patients (29%) presented with stroke, 20 (57%) with
transient ischemic attacks (TIAs) and five (14%) were asymptomatic. The
incidence of stroke was higher in type IV (50%) vs. type II (30%) and
in type II vs. type I (10%) lesions. Similarly, TIAs presented more
often in type II (67%) and IV (50%) vs. in type I (40%) lesions (p =
0.002). Retrograde flow in the ophthalmic artery and concomitant severe
contralateral carotid artery stenosis were more often related with type
II and IV lesions (p = 0.02 and 0.04, respectively). CCAO is usually
accompanied by patent distal vessel(s). The proposed CCAO classification
correlates well with the patients’ clinical status and may help to
better clarify the outcome of this rare entity. Among the main arteries
of the developed collateral circulation, only the flow direction in the
ophthalmic artery may be of clinical value. (E-mail:
[email protected]) (c) 2008 World Federation for Ultrasound in
Medicine & Biology
