Strategy for treating unruptured vertebral artery dissecting aneurysms

Background The natural course of unruptured vertebral artery dissecting aneurysms (VADAs) remains unclear. Objective The purpose of this retrospective study was to develop a strategy for treating unruptured VADAs based on long-term follow-up. Methods Our study population consisted of 100 patients with unruptured VADAs; in 66, the initial symptom was headache only, 30 presented with ischemic symptoms and 4 with mass effect. All underwent magnetic resonance imaging and magnetic resonance angiography at the time of admission and 2 weeks and 1, 3, 6, 12, and 24 months after the onset. If the dissection site was demonstrated to be enlarged on magnetic resonance imaging and magnetic resonance angiography without the manifestation of new symptoms, the patients received additional treatment to prevent bleeding. Results Of the 100 patients, 4 underwent early intervention because of symptom exacerbation. The other 96 were initially treated conservatively; during follow-up, 5 manifested lesion enlargement on magnetic resonance angiography. Nine patients received additional treatment; 1 underwent direct surgery with trapping of the dissection site, and 8 underwent coil embolization. The other 91 patients continued to be treated conservatively; the dissection site remained unchanged in 70, improved or healed in 18, and disappeared in 3 patients. We treated 38 patients with recurrent ischemic attacks with antiplatelet therapy. No patients experienced bleeding or permanent neurological deficits during follow-up. Conclusion The nature of an unruptured VADA is not highly aggressive. However, if the dissection site enlarges without the manifestation of new symptoms, it should be occluded. In patients with recurrent ischemic attacks antiplatelet therapy should be considered.