Could you tell me what happens when a carotid artery gets nicked?

"Nicked": "nicked" is a word some physicians use to describe an unintentional injury caused in the process of providing medical care by a trained person. Depending on the extent of the injury to the carotid artery, the consequences can range from nothing to causing a stroke. This would be really unfortunate, but these things can and do happen with some regularity.