Treatment of a Giant Thrombotic M1 Segment Middle Cerebral Artery Aneurysm With Radial Artery Bypass and Distal Occlusion to Create a "Blind Sac" Following Endovascular Failure: 2-Dimensional Operative Video.

The case is of a 36-yr-old male with a previously coiled aneurysm arising from the proximal M1 segment of the middle cerebral artery (MCA) just beyond the internal carotid artery (ICA) bifurcation who presented to our institution with subjective left hemiparesis, headache, and vomiting. Physical exam revealed a left facial droop, but neurological exam was otherwise normal, including full motor strength. Neuroimaging showed a large partially thrombosed aneurysm recurrence, measuring 5.2 cm, with obstructive hydrocephalus. Cerebral angiogram showed filling within a small portion of the aneurysm and marked stenosis of the MCA beyond the neck. A ventriculostomy was placed, and he underwent a pterional craniotomy for high-flow radial artery bypass from the common carotid artery to an M2 branch of the MCA and clip placement. This case demonstrates the creation of a blind sac by placing a clip on the MCA distal to the aneurysm and proximal to the lenticulostriate arteries for the treatment of a giant proximal M1 segment aneurysm. Postoperative digital subtraction angiography shows the MCA distribution, including the lenticulostriate arteries, filling through the radial artery bypass, and anterograde flow through the ICA, which perfuses up to and including the anterior choroidal artery. There is no residual filling of the aneurysm. The patient remained at his neurological baseline postoperatively and required ventriculoperitoneal shunt placement for hydrocephalus. At outpatient follow-up, computed tomography imaging showed decreased size of the thrombosed aneurysm, measuring 4.5 cm, and he had no neurological deficits. The patient gave informed consent for surgery and deidentified video recording of this case.