Any lethal complications to carotid endarterectomy ?

Plenty: Most dreaded complication is a stroke, and a minority of these can be lethal. In some patients, bleeding in the surgical bed can lead to a collection of blood/fluid that generate enough pressure to impair airway function, this is a life threatening condition. Heart attacks, pulmonary emboli and arterial dissection can also happen, but fairly rairly.

Yes: Death can be a complication of carotid surgery but this is very rare. Most people that have carotid disease have coronary heart disease as well. This is why most people need cardiac evaluation prior to carotid surgery. Carotid surgery should be done by a board certified vascular surgeon who has a track record of very low stroke rate and mortality.

Stroke: But small chance. Make sure surgeon experienced.