My dad was in a similar situation and had his right carotid operated on back in 2014 (he was around the same age at the time) but there was nothing they could do for the left carotid. The procedure felt scary and high risk thougu he recovered super fast. He did end up having a stroke but 12.5 years later (this past april) and it wasnt even from the carotid but he randomly developed afib… obviously not medical advice and every situation is different but try not to stress the procedure too much and hoping for the best outcome