A 65-year-old woman with a T4, N1, M0 squamous cell carcinoma of the left retromalar trigone and mandible had a composite resection with modified radical neck dissection and tracheostomy followed by a free flap reconstruction. On the morning after surgery, the patient appeared slightly less responsive and remained ventilated. Eventually she became more responsive; however, she continued to have poor movements of all her extremities.

Our patient had a perioperative watershed stroke due to a combination of arterial hypotension and carotid artery stenosis. Arterial hypotension and poor cerebral perfusion are important factors in the production of perioperative strokes. Patients with severe carotid artery disease are at high risk of perioperative watershed infarction.