LAUSR

BACKGROUND Blister aneurysms are rare, technically challenging lesions that are typically ill defined and arise at nonbranch points of arteries. OBJECTIVE To describe the microsurgical treatment of a ruptured blister aneurysm at the internal carotid artery (ICA) terminus using the reverse picket fence clipping technique. METHODS The patient was a 60-yr-old male. He presented with a Hunt and Hess Grade 2, Fisher Grade 3 subarachnoid hemorrhage located in the bilateral sylvian fissures (right > left) and suprasellar cisterns. Computed tomography angiography demonstrated 2 aneurysms: a 2-mm right middle cerebral artery (MCA) aneurysm and a 2.5-mm right internal carotid artery (ICA) terminus blister aneurysm. Transradial cerebral angiography was undertaken which showed these similar sized aneurysms. Microsurgical treatment was chosen, and the patient underwent a right pterional craniotomy for clipping of his aneurysms. The patient consented to the procedure. RESULTS The combination of stacked fenestrated clips repaired the vessel, with intraoperative fluorescein and indocyanine green angiography demonstrated normal filling of the MCA and ICA circulation with no delay. Intraoperative angiography confirmed induced moderate stenosis of the ICA terminus at about 50%, which is essential to close the blister aneurysm site by utilizing a portion of the normal vessel wall. CONCLUSION Ruptured blister aneurysms at the ICA terminus can be safely repaired using the reverse picket fence technique for clipping.