Background and purpose: The natural history of aneurysmal forms of cervical artery dissection (CAD) is ill defined. The aims of this study were to assess (1) clinical and anatomic outcome of aneurysmal forms of extracranial internal carotid artery (ICA) and vertebral artery (VA) dissections and (2) factors associated with aneurysmal forms of CAD.
Methods: Seventy-one consecutive patients with CAD were reviewed. Aneurysmal forms of CAD were identified from all available angiograms by 2 neuroradiologists. The frequency of arterial risk factors, of multiple vessel dissections, and of artery redundancies was compared in patients with and without aneurysm. Patients with aneurysm were invited by mail to undergo a final clinical and radiological evaluation.
Results: Of the 71 patients, 35 (49.3%) had a total of 42 aneurysms. Thirty aneurysms were located on a symptomatic artery (ICA, 23; VA, 7) and 12 on an asymptomatic artery (ICA, 10; VA, 2). Patients with aneurysm had multiple dissections of cervical vessels (18/35 versus 7/36; P:=0.005) and arterial redundancies (20/35 versus 11/36; P:=0.02) more frequently than patients without aneurysm. They were also more often migrainous (odds ratio=2.7 [95% CI, 0.8 to 8.5]) and tobacco users (odds ratio=2.2 [95% CI, 0.7 to 6.3]). Clinical and anatomic follow-up information was available for 35 (100%) and 33 patients (94%), respectively. During a mean follow-up of >3 years, no patient had signs of cerebral ischemia, local compression, or rupture. At follow-up, 46% of the aneurysms involving symptomatic ICA were unchanged, 36% had disappeared, and 18% had decreased in size. Resolution was more common for VA than for ICA aneurysms (83% versus 36%). None of the aneurysms located on an asymptomatic ICA had disappeared.
Conclusions: Although aneurysms due to CAD frequently persist, patients carry a very low risk of clinical complications. This favorable clinical outcome should be kept in mind before potential harmful treatment is contemplated.