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. We describe a case of a 48-year-old man with a recurrent thrombosed right MCA aneurysm. We performed MCA-to-MCA bypass using the superficial temporal artery (STA) interposition graft and proximal trapping. Initially, an STA-to-MCA bypass with aneurysm trapping was planned because one 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 back flow 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 neurological 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. Thus, 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 the 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 a good STA backflow is guaranteed.