Gadolinium Enhancement of the Aneurysm Wall in Extracranial Carotid Artery Aneurysms.

BACKGROUND AND PURPOSE: The natural history and optimal treatment of extracranial carotid artery aneurysms are unknown. Gadolinium enhancement of the aneurysm wall may reflect aneurysm wall inflammation and instability. In this study, we investigated the feasibility of extracranial carotid artery aneurysm wall imaging and explored a potential relationship of aneurysm wall enhancement with aneurysm growth and the presence of (silent) brain infarcts and white matter lesions. MATERIALS AND METHODS: Fourteen conservatively treated patients with 15 asymptomatic extracranial carotid artery aneurysms underwent gadolinium-enhanced 3T MR imaging at 2 time points with a 12-month interval. Primary outcome was growth of the aneurysm sac (≥2.0 mm); secondary outcomes were the presence of (silent) brain infarcts and white matter lesions at baseline and follow-up. MR images were reviewed by 2 independent observers, and inter- and intraobserver reproducibility was assessed. RESULTS: Seven (50%) patients were men; the median age was 55 years (range, 40-69 years). Eleven extracranial carotid artery aneurysms (73%) were saccular (median size, 11 mm; range, 5.0-38.5 mm), and 4 were fusiform (median size, 21.5 mm; range, 10.0-40.0 mm). Eleven of 15 aneurysms (73%) exhibited gadolinium enhancement at baseline. Four aneurysms (27%) showed growth at follow-up imaging, 2 gadolinium-positive (+) and 2 gadolinium-negative (-) (P = .245). Three patients (21%) had ipsilateral brain infarcts at baseline; 1 of them showed a new silent brain infarct at follow-up imaging (gadolinium+). Nine patients (64%) showed bilateral white matter lesions at baseline. In 3 patients, increased white matter lesion severity was observed at follow-up (2 gadolinium+). All observations showed excellent inter- and intraobserver reproducibility. CONCLUSIONS: In this explorative study, we demonstrated that extracranial carotid artery aneurysm wall imaging was feasible. Future well-powered studies are needed to investigate whether extracranial carotid artery aneurysm gadolinium enhancement predicts aneurysm growth and thromboembolic complications.

Experience of a single center in the conservative approach of 20 consecutive cases of asymptomatic extracranial carotid artery aneurysms.

BACKGROUND AND PURPOSE: The clinical course and optimal treatment strategy for asymptomatic extracranial carotid artery aneurysms (ECAAs) are unknown. We report our single-center experience with conservative management of patients with an asymptomatic ECAA. METHODS: A search in our hospital records from 1998 to 2013 revealed 20 patients [mean age 52 (SD 12.5) years] with 23 ECAAs, defined as a 150% or more fusiform dilation or any saccular dilatation compared with the healthy internal carotid artery. None of the aneurysms were treated and we had no pre-defined follow-up schedule for these patients. The primary study end-point was the yearly rate for ipsilateral ischemic stroke. Secondary end-points were ipsilateral transient ischemic attack, any stroke-related death, other symptoms related to the aneurysm or growth defined as any diameter increase. RESULTS: The ECAA was either fusiform (n = 6; mean diameter 10.2 mm) or saccular (n = 17; mean diameter 10.9 mm). Eleven (55%) patients with 13 ECAAs received antithrombotic medication. During follow-up [median 46.5 (range 1-121) months], one patient died due to ipsilateral stroke and the ipsilateral cerebral stroke rate was 1.1 per 100 patient-years (95% confidence interval, 0.01-6.3). Three patients had ECAA growth, two of whom were asymptomatic and one was the patient who suffered a stroke. CONCLUSIONS: In this retrospective case series of patients with an asymptomatic ECAA, the risk of cerebral infarction is small but not negligible. Conservative management seems justified, in particular in patients without growth. Large prospective registry data are necessary to assess follow-up imaging strategies and the role of antiplatelet therapy.

Prevalence of extracranial carotid artery aneurysms in patients with an intracranial aneurysm.

BACKGROUND AND PURPOSE: Aneurysms in various arterial beds have common risk- and genetic factors. Data on the correlation of extracranial carotid artery aneurysms (ECAA) with aneurysms in other vascular territories are lacking. We aimed to investigate the prevalence of ECAA in patients with an intracranial aneurysm (IA). METHODS: We used prospectively collected databases of consecutive patients registered at the University Medical Center Utrecht with an unruptured intracranial aneurysm (UIA) or aneurysmal Subarachnoid hemorrhage (SAH). The medical files of patients included in both databases were screened for availability of radiological reports, imaging of the brain and of the cervical carotid arteries. All available radiological images were then reviewed primarily for the presence of an ECAA and secondarily for an extradural/cavernous carotid or vertebral artery aneurysm. An ECAA was defined as a fusiform dilation ≥150% of the normal internal or common carotid artery or a saccular distention of any size. RESULTS: We screened 4465 patient records (SAH database n = 3416, UIA database n = 1049), of which 2931 had radiological images of the carotid arteries available. An ECAA was identified in 12/638 patients (1.9%; 95% CI 1.1-3.3) with completely imaged carotid arteries and in 15/2293 patients (0.7%; 95% CI 0.4-1.1) with partially depicted carotid arteries. Seven out of 27 patients had an additional extradural (cavernous or vertebral artery) aneurysm. CONCLUSIONS: This comprehensive study suggests a prevalence for ECAA of approximately 2% of patients with an IA. The rarity of the disease makes screening unnecessary so far. Future registry studies should study the factors associated with IA and ECAA to estimate the prevalence of ECAA in these young patients more accurately.