Rescue endovascular treatment for rapid regrowth of aneurysm remnant on middle cerebral artery trunk after unsuccessful surgical clipping in patients with a ruptured cerebral aneurysm: A report of two cases.

We report two rare cases treated with coiling after rapid regrowth (within a month) of an aneurysm remnant on the middle cerebral artery (MCA) trunk after incomplete surgical clipping. The first case, a 47-year-old man with subarachonoid hemorrhage (SAH) (Hunt-Hess grade II, Fisher grade III) underwent clipping of a ruptured saccular aneurysm with a wide neck on the right early frontal branch arising from the MCA trunk. Incomplete clipping with a 1 mm sized remnant neck was performed to avoid sacrificing the lenticulostriate artery. In a follow-up cerebral angiogram on postoperative day 30, a rapid regrowth of the aneurysm remnant was observed, and on that day, complete obliteration was obtained by rescue endovascular treatment. The second case, a 48-year-old healthy woman with SAH (Hunt-Hess grade II, Fisher grade III) underwent clipping of an anteroposteriorly projecting bilobulated aneurysm on the left M1. Incomplete clipping with a minimal remnant neck was performed. In follow-up digital subtraction angiogram on postoperative day 30, a rapid regrowth of an aneurysm remnant involving only a part of the initial aneurysm near the neck was observed, and on that day, complete obliteration was obtained by rescue coiling. These patients were both discharged without any neurological deficits.