<s>[INST] I have a dissected right carotid artery with an aneurysm. I was informed that if I surgery to correct it that there would be a 50/50 chance of the surgery being fatal. Is this true? I m only 52 years old I ve had this for 2 years.I go in for regular MRI s and CT scans but just worry about if it. [/INST] Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. After going through your medical details I understand your concern and I would like to tell you that dissected carotid aneurysm means you are already at death risk , in such case going for carotid surgery means you are giving yourself 50% chances to live and is highly recommended to go for this as soon as possible. Hope I have answered your query. Let me know if I can assist you further. </s>