Bonnet Bypass for Left Superficial Temporal Artery Bifurcation to Right Middle Cerebral Artery: 2-Dimensional...

A bonnet bypass is a long interposition graft bypass used for extracranial to intracranial revascularization, which is useful in patients who do not have a suitable ipsilateral donor or in whom the ipsilateral donor must be sacrificed. This interposition graft is commonly the radial artery or saphenous vein. The only practical difference in this technique for revascularization is that an interposition graft must pass through the subgaleal space to the contralateral scalp to allow for reimplantation at the desired contralateral point of anastomosis. This patient underwent a bonnet bypass for revascularization of the middle cerebral artery (MCA) perfusion territory utilizing the contralateral superficial temporal artery (STA). A saphenous vein was used as the interposition graft, which was anastomosed to an M2 segment bifurcation. The graft was then temporarily occluded and passed within a calvarial trough to the contralateral frontoparietal region. The graft was then anastomosed to the contralateral STA at a bifurcation to accommodate the graft size mismatch. The patient tolerated the bypass procedure well and demonstrated bypass patency on postoperative angiographic imaging. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.