Cortical blindness, transient and otherwise, associated with detachable coil embolization of intracranial aneurysms

BACKGROUND AND PURPOSE: Cortical visual loss is a rare complication of cerebral angiography without a definitive pathophysiology. Given the rapid increase in endovascular procedures used to treat cerebral aneurysms, we explored the prevalence of this complication and whether we could add to the understanding of this disorder.Materials and METHODS: We performed a retrospective review of all procedures performed with the same contrast agent and detachable coils for treatment of posterior circulation aneurysms by 1 endovascular surgery service from 1996 to 2006. All patients were evaluated before and after each procedure by a team that included a neuro-ophthalmologist.RESULTS: Of 137 intra-arterial treatment procedures performed for posterior circulation aneurysms, we identified 4 patients with cerebral vision loss complications. During the same time period, >500 aneurysms of the anterior cerebral circulation were treated without this complication. The visual field loss was unilateral in 2 and bilateral in 2 patients. Recovery was complete in 3 and almost normal in the fourth patient. The amount of contrast used and the duration of the procedure were similar among all patients. The 4 patients had no identified specific risk factors for developing procedure-associated occipital dysfunction, all 4 had undergone prior angiography, and 1 patient had undergone repeat coiling, without complication.CONCLUSION: The 2.9% prevalence of cerebral visual loss with endovascular coil treatment of posterior circulation aneurysms is higher than that for angiography alone. Our patients recovered well with corticosteroid and intravenous hydration treatment. Recognizing the self-limiting nature of this problem might prevent an unneeded intervention.

Endosaccular occlusion procedures with detachable coils are used with increasing frequency in the treatment of intracranial aneurysms because of clinical effectiveness, good clinical outcome, and low complication rates.^1,2 Endovascular procedures necessitate repeated intra-arterial contrast injections to evaluate therapeutic progress and to avoid or reverse complications such as emboli or unplanned arterial occlusion. Transient cortical blindness is a rare but known complication after administration of angiographic contrast agent,³ which has been reported in 0.3%–1% of patients undergoing vertebral angiography.^4,5 The prevalence could be higher in patients with vasculopathy, even with carotid artery injections,⁶ or with older techniques.^7,8 The exact mechanism for this problem has not been proved. We encountered this complication in 4 patients who had endovascular treatment of posterior circulation aneurysms, which has been reported twice.^9,10