Table IV.

P values from Chi squared analysis of risk factors predictive of contralateral operation, neurologic event in follow-up, and death.

Risk Factor	Contralateral operation	Neurologic Event in follow up	Death
Prior Neck irradiation	0.68	0.17	.054§
Symptoms present at initial presentation	0.57	0.47	0.075
Amurosis Fugax at initial presentation	0.078§	0.76	0.44
Contralateral ICA progression in follow up	0.20	0.47	0.49
Ipsilateral ECA at presentation	0.17	0.19	0.005
Contralateral ECA at presentation	0.005	0.56	0.014
Ipsilateral Vert in follow up		0.019	0.29
Ipsilateral ECA in follow up	0.033	0.073	<.0001*
Contralateral ECA in follow up	0.62	0.46	0.061
Any ECA/Vertebral stenosis or occlusion at presentation	0.053	0.098	0.007
ECA/Vertebral stenosis or occlusion progression in follow up	0.29	0.427	0.31

^*p<.05 in multivariate analysis.

^§p=0.05 in multivariate analysis. Ipsilateral refers to the occluded side and contralateral is the non-occluded side.

ICA, Internal Carotid Artery; ECA, External Carotid Artery; Vert, Vertebral artery.