Middle Cerebral Artery–to–Middle Cerebral Artery Bypass with Superficial Temporal Artery Interposition Graft for the Treatment of Recurrent Thrombosed Middle Cerebral Artery Aneurysm

Microsurgical treatment of thrombosed middle cerebral artery (MCA) aneurysm is very complicated, especially in recurrent cases. A 48-year-old man presented with a recurrent thrombosed right MCA aneurysm. We performed MCA-to-MCA bypass using a superficial temporal artery (STA) interposition graft and proximal trapping. Initially, an STA-to-MCA bypass with aneurysm trapping was planned because 1 MCA branch of the superior trunk of the M2 segment needed flow replacement after aneurysm trapping. However, the blood flow from the proximal STA was insufficient because of the previous surgical trauma and redo clipping was not feasible. As the backflow from the distal STA segment was good, we used it as an interposition graft for the MCA-to-MCA bypass. The patient recovered well without any neurologic deficits. In this case, the recurrent aneurysm was a fusiform MCA-M2 segment aneurysm with clip slippage. Our initial surgical plan could not be executed. We changed our surgical plan to an MCA-interposition graft-MCA bypass considering the mobility of the M3 arteries. The options for interposition grafts included radial artery, saphenous vein, or ipsilateral or contralateral STA. The caliber discrepancy in the radial artery or saphenous vein grafts makes them less suitable. Further, harvesting the contralateral STA is time-consuming and tedious. Thus the ipsilateral STA interposition graft was used and showed promising results. We recommend this surgical technique in cases in which good STA backflow is guaranteed. In conclusion, revision surgery performed for a recurrent thrombosed MCA aneurysm with an MCA-STA interposition graft-MCA bypass with proximal trapping was successful. This technique is safe and effective for complex aneurysms with suboptimal condition of the STA, which could be due to reduced blood flow, previous surgery, or trauma.