The Fate of the External Carotid Artery after Carotid Artery Stenting. A Follow-up Study with Duplex Ultrasonography☆

Objective

To evaluate the long-term effect of carotid angioplasty and stenting (CAS) of the internal carotid artery (ICA) on the ipsilateral external carotid artery (ECA).

Subjects and Methods

We prospectively registered the pre- and post-interventional duplex scans obtained from 312 patients (mean age 70 years) who underwent CAS. Duplex scans were scheduled the day before CAS, 3 and 12 months post-procedurally and yearly thereafter, to study progression of obstructive disease in the ipsilateral ECA compared to the contralateral ECA. The duplex ultrasound criteria used to identify ECA stenosis ≥50% were Peak Systolic Velocities of ≥125cm/s.

Results

Preprocedural evaluation of the ipsilateral ECA demonstrated ≥50% stenosis in 32.7% of cases vs 30% contralateral. Both ipsilateral and contralateral 3 (1%) ECA occlusions were noted. After stenting 5 (1.8%) occlusions were seen vs 1% contralateral. No additional ipsilateral occlusions and 2 additional contralateral oclusions were noted at extended follow-up. The prevalence of ≥50% stenosis of the ipsilateral ECA (Kaplan-Meier estimates) progressed from 49.1% at 3, to 56.4%, 64.7%, 78.2%, 72.3%, and 74% at 12, 24, 36, 48, and 60 months respectively. Contralateral prevalences were 31.3%, 37.7%, 41.7%, 43.1%, 46.0%, and 47.2% respectively (p<0.001). Progression of stenosis was more pronounced in 234 patients (75%) with overstenting of the carotid bifurcation (p=0.004).

Conclusion

Our results show that significant progression of ≥50% stenosis in the ipsilateral ECA occurs after CAS. There was greater progression of disease in the ipsilateral compared with the contralateral ECA. Progression of disease in the ECA did not lead to the occurrence of occlusion during follow up.

Keywords: CAS, External carotid artery, Duplex US, Follow-up stenosis