Progressive visual loss due to a muslinoma--report of a case and review of the literature.

Intracranial internal carotid artery (ICA) aneurysms are frequently treated either by microsurgical clipping of the aneurysm neck, by endovascular coiling of the aneurysm sac or by balloon occlusion of the parent vessel. For some broad-based aneurysms that may not be suitable for any of these options, microsurgical wrapping of the aneurysm wall with muslin or gauze rarely is applied. We report the case of a patient who suffered from a minor stroke because of arterio-arterial embolism from an intracranial ICA aneurysm. The aneurysm was treated by wrapping muslin material. After 12 months, he experienced progressive visual loss. Cranial magnetic resonance testing magnetic resonance tomography (MRT) revealed a granulomatous inflammation surrounding the site of the aneurysm and affecting optochiasmatic structures. A muslin-induced optic neuropathy is a rare but serious complication of a chronic inflammatory reaction in response to muslin or gauze used in intracranial aneurysm wrapping. If the foreign body inflammatory reaction to muslin or gauze leads to a mass formation, the term muslinoma or gauzoma is applied. Various treatment strategies include surgery, steroids and cyclophosphamide, but recovery of the vision is not predictable. As a consequence, muslin or cotton gauze should only be applied with great caution in neurovascular surgery.