Visual worsening after incomplete coiling of a small asymptomatic aneurysm: case report and review of the literature

Abstract

Objective: Complications with increased mass effect on surrounding structures have as yet only been noted after coiling of large, giant, and thrombosed aneurysms. We describe a case of optic chiasm compression after incomplete coil embolization of a small ICA aneurysm and discuss the potential mechanisms causing this phenomenon.

Case report: A 57-year-old male presented with an incidental, 7-mm diameter, C2 segment, ICA aneurysm. Endovascular intervention with platinum coils resulted in 80% obliteration. Approximately three weeks later the patient developed visual changes which progressed over 10 days to a homonymous hemianopsia with a central scotoma. A pterional craniotomy was performed to decompress and to definitively clip the aneurysm. Histological evaluation of the aneurysm showed sinusoidal vessels, filled with proliferated endothelial cells and being encapsulated by fibrous tissue, suspicious for exposure to systemic blood pressure.

Conclusion: Even small aneurysms undergoing incomplete coil embolization may affect surrounding, eloquent neural structures due to unexpected tissue formation in the aneurysm.