Management of Previously Failed Coiling and Clipping of a Middle Cerebral Artery Aneurysm.

Endovascular coiling techniques have emerged as an alternative and effective approach for treating intracranial aneurysms. However, in some cases, previously coiled aneurysms may require secondary treatment with surgical clipping, presenting a more complex challenge compared with the initial intervention. We present the case of a 39-year-old man with a residual class III Raymond-Roy occlusion partially coiled aneurysm at the left middle cerebral artery bifurcation (Video 1). Faced with the risks of rerupture, the patient underwent microsurgical treatment after providing consent. Despite successful initial microsurgical clipping, postoperative complications arose due to coil protrusion into the middle cerebral artery bifurcation, resulting in thrombotic occlusion of the frontal M2 branch. Emergency repeat microsurgical intervention and administration of a thrombolytic agent were performed to address complications, ultimately preserving blood flow. Subsequent endovascular placement of a flow-diverting stent 7 weeks after discharge confirmed complete occlusion of the aneurysm. The patient had no neurological deficit on follow-up. When planning microsurgical clipping of an aneurysm previously treated with coils, it is critical to consider coil placement, as there is a risk of prolapse if the coil is in the neck of the aneurysm. Thrombosis of the cerebral arteries is a potential complication of microsurgical clipping of partially coiled intracranial aneurysms, and injection of a fibrinolytic agent into thrombosed arterial branches may be an effective intraoperative method for treating intra-arterial thrombosis. This case illustrates the challenges associated with treating partially coiled aneurysms, highlighting the significance of careful planning when considering microsurgical treatment.