Objective: The clinical and angiographic follow-up results for intracranial vertebral artery (VA) dissections that initially presented without subarachnoid hemorrhage (SAH) were retrospectively investigated, to clarify their management.
Methods: Twenty-one patients with VA dissections that initially presented without SAH were studied. Initial angiography revealed aneurysmal dilation in 11 cases (typical pearl-and-string sign in 8 cases, aneurysmal dilation only in 2, and aneurysmal dilation with double-lumen sign in 1), occlusion in 7, double-lumen sign in 2, and string-like stenosis in 1. Nine patients (six with pearl-and-string sign, one with occlusion with aneurysmal dilations, and two with double-lumen sign), including three patients who experienced subsequent SAH, underwent endovascular proximal parent artery occlusion. The other 12 patients were treated conservatively. All patients were monitored with magnetic resonance angiography or digital subtraction angiography.
Results: Three patients experienced subsequent SAH, 1 day (two patients) or 51 months after onset. Follow-up angiographic assessments of the 20 patients demonstrated complete resolution in five cases, reduction of aneurysmal dilation in one case, and partial recanalization in one case. However, enlargement or formation of an aneurysmal dilation was recognized in four cases and progression of dissection was observed in one case. Eighteen patients experienced good recoveries, and three patients demonstrated moderate disabilities as a result of the initial ischemic insult.
Conclusion: The risk of bleeding from unruptured VA dissections is higher than previously considered. Therefore, endovascular treatment should be considered for patients with VA dissections with relatively large or growing aneurysmal dilations.