Carotid angioplasty with internal carotid artery flow reversal is well tolerated in the awake patient☆

Abstract 

Objective

The purpose of this study was to evaluate the neurologic tolerance and changes in ipsilateral hemispheric oxygen saturation during transcervical carotid artery stenting with internal carotid artery (ICA) flow reversal for embolic protection.

Patients and methods

This was a prospective study of 10 patients (mean age 68 years) undergoing transcervical carotid angioplasty and stenting. All ICA stenoses were greater that 70%. Seven patients had an ipsilateral hemispheric stroke (3) or transient ischemic attack (4), two patients had a contralateral stroke, and one patient was asymptomatic. Nine procedures were done under local anesthesia. Cerebral protection was established through a cervical common carotid (CCA) cutdown to create an external fistula between the ICA and the internal jugular vein with temporally CCA occlusion. Venous oxygen saturation (SVO₂) was continuously monitored through a catheter placed in the distal internal jugular vein. Mental status and motor-sensory changes were categorized and assessed throughout and after the procedure.

Results

All procedures were technically successful without significant residual stenosis. Mean ICA flow reversal time was 22 minutes (range, 15 to 32). Common carotid artery (CCA) occlusion produced a slight (SVO₂ = 72.6%+/-9.4) but significant decrease (P = .012) in SVO₂, compared with baseline (SVO₂ = 77% +/-10.5). During ICA flow reversal (SVO₂ = 72.4% +/-10.1) cerebral oxygen saturation did not change compared with CCA occlusion alone (P = .85). Transient balloon occlusion during angioplasty of the ICA (SVO₂ = 64.6%+/-12.9) produced a significant decrease in cerebral SVO₂ compared with CCA occlusion (P = .015) and compared with CCA occlusion with ICA flow reversal (P = .018). No mental status changes or ipsilateral hemispheric focal symptoms occurred during CCA occlusion with ICA flow reversal. One patient with contralateral ICA occlusion sustained brief upper extremity weakness related to the contralateral hemisphere. Five patients sustained a vasovagal response during balloon dilatation, four did not require treatment, and one had asystole requiring atropine injection. Mean SVO₂ saturation was not different in these five patients compared with the five who did not sustain a vasovagal response. No deaths or neurologic deficits occurred within 30 days after the procedure.

Conclusions

Our data suggest that transcervical carotid angioplasty and stenting with ICA flow reversal is well tolerated in the awake patient, even in the presence of symptomatic carotid artery disease. Cerebral oxygenation during ICA flow reversal is comparable to that during CCA occlusion. ICA angioplasty balloon inflation produces a decrease in cerebral SVO₂ significantly greater than that occurring during ICA flow reversal.