Microsurgical Nuances of Clipping a Large Thrombosed Aneurysm with Intraoperative Dome Incision and Ultrasonic Aspiration.

We present the case of a 64-year-old male with a 5-day history of headaches. Magnetic resonance angiography revealed a 15 mm × 15 mm diameter aneurysm in the left middle cerebral artery arising in the region of the first branch of the middle cerebral artery-second branch of the middle cerebral artery (M2) bifurcation. Angiography revealed the lesion arose from the M2 vessel that contained a large amount of thrombus. Follow-up magnetic resonance angiography at 2 months revealed an enlargement of the lesion (16 mm × 17 mm), while a follow-up angiogram showed a decrease in the filling component of the lesion, suggesting further thrombosis. Given its rapid growth, endovascular and surgical options were considered and microsurgery was decided on. The aneurysm was accessed through the Sylvian fissure, and the M2 vessel was identified at the neck of the lesion where it entered and exited. We performed an intraaneurysmal thrombus evacuation to make the lesion clippable. We used a No. 11 blade and opened the dome away from the neck. Through this 3- to 4-mm incision, we inserted the tip of the ultrasonic aspirator device and used it to evacuate the thrombus in a circumferential fashion. This allowed for wall-to-wall apposition when deploying the aneurysm clip. A Sugita 15-mm clip (Mizuho America Inc., Los Angeles, California, USA) was used to obliterate the lesion. Both microvascular ultrasound and intraoperative angiography were used to confirm patency and flow distal to the aneurysm. In Video 1, we narrate the case and essential details of this approach. Neither Institutional Review Board nor patient consent was required to report this case with no identifiable patient information.