Revascularization for Cerebral Ischemia, Step-by-Step Demonstration of Bonnet Bypass: 3-Dimensional Operative Video

The superficial temporal artery (STA) to the middle cerebral artery (MCA) bypass is the most common bypass type for revascularization to treat cerebral ischemia. If the ipsilateral STA is not available for anastomosis, various options for bypass conduits can be exercised. When the entire ipsilateral external carotid and its branches are not available, the contralateral STA may be used as a donor artery through an interposition graft. This technique is known as a "bonnet bypass." In this video, we demonstrate the utilization of a bonnet bypass in a 48-yr-old man with protein S deficiency, and right carotid artery occlusion with recurrent strokes and transient ischemic attacks (TIA). After exhausting nonsurgical options by treating with 2 antiplatelet drugs and supportive lifestyle changes, the patient continued to experience TIAs and watershed strokes in the right hemisphere. Angiography showed that the right anterior artery and the MCA were filled through the Circle of Willis, but the ipsilateral STA and entire external and common carotid arteries were not patent for potential use as a bypass donor. Since the ipsilateral bypass options were not available, we elected to perform a bypass from the contralateral STA trunk to the ipsilateral M2 with a saphenous vein interposition graft, for a so-called bonnet bypass. The patient did well after surgery and has remained symptom-free for 19 mo post bypass. The surgical technique and each step in performing this bonnet bypass are demonstrated in this 3-dimensional video. The patient consented to the publication of his operative video.