Delayed development of aneurysmal dilatations in patients with extracranial carotid artery dissections.

BACKGROUND AND PURPOSE

Dissection of the carotid artery (CaAD) may result in aneurysm formation. The present study was undertaken to evaluate time of onset of dissecting extracranial carotid artery aneurysms (ECAA) following CaAD, and analyse independent risk factors for development of these aneurysms.

METHODS

From four European stroke centres, we included 360 patients with extracranial CaAD. We analysed the time between the estimated dissection onset and aneurysm formation and assessed the clinical risk factors increasing aneurysm probability.

RESULTS

Median follow-up was 5.2 months (range 0-24). A total of 75 dissecting ECAA were identified in 70 patients (19.4%, 95% CI 15.7-23.8%). In 52/70 (74%) patients, the ECAA was diagnosed at initial clinical work-up of CaAD diagnosis, median of the estimated time of dissection onset to ECAA diagnosis being 6 days (interquartile range (IQR) 0-25). In the remaining 18 (26%) who had normal carotids at the initial imaging, aneurysm diagnosis was made median 6.2 months from the original imaging (189 days, IQR 128-198). Cox proportional hazards model showed that both multiple artery dissections (2.58 HR, 95% CI 1.54-4.33) and arterial tortuosity (1.79 HR, 95% CI 1.08-2.95) were associated with presence of ipsilateral ECAA.

CONCLUSION

This post hoc cohort analysis showed substantial delayed development of ipsilateral ECAA in CaAD patients months after baseline. Multiple dissections and arterial tortuosity are associated with the presence of ECAA and can be used in future prediction models of ECAA development in CaAD patients.