Introduction: Paraclinoid aneurysms commonly present with visual impairment. They were traditionally treated with clipping or coiling, but flow diversion has recently been introduced as an alternative treatment modality. Although there is still initial aneurysm thrombosis, flow diversion is hypothesized to reduce mass effect, which may decompress the optic nerve when treating visually symptomatic paraclinoid aneurysms. We performed a meta-analysis to compare vision outcomes following clipping, coiling, or flow diversion of paraclinoid aneurysms in patients presenting with visual impairment.
Methods: A systematic literature review was performed using the PubMed and Web of Science databases. Studies written in English between 1980-2016 were included if they reported preoperative and postoperative visual function in at least 5 patients with visually symptomatic paraclinoid aneurysms (cavernous segment through ophthalmic segment) treated with clipping, coiling, or flow diversion. Neuro-ophthalmologic assessment was used when reported.
Results: Thirty-nine studies totaling 2458 patients (20%, 510 of whom presented with visual symptoms) met our inclusion criteria, including 309 visually symptomatic cases treated with clipping (mean follow-up, 25.9 mo), 138 treated with coiling (17.1 mo), and 63 treated with flow diversion (11 mo). Postoperative vision in these patients was classified as improved, unchanged, or declined compared to preoperative vision. We found that vision improved in 57% (95% CI 47-67) of patients after clipping, 45% (34-57) after coiling, and 73% (56-88) after flow diversion. Vision worsened in 11% (7-17) of patients after clipping, 8% (2-17) after coiling, and 7% (0-27) after flow diversion. New visual deficits were found in patients with intact baseline vision at a rate of 0.69% (0-2) for clipping, 0.53% (0-3) for coiling, and 0.80% (0-3) for flow diversion.
Conclusion: Our data demonstrates a high rate of visual improvement and a low rate of iatrogenic vision impairment for patients with paraclinoid aneurysms treated with flow diversion. Further analysis is needed to compare flow diversion to clipping and coiling and inform clinical management of visually symptomatic paraclinoid aneurysms.