Sandie, I'm sorry for your troubles, fast moving events, and absence of your doctor.
I had my carotid artery consisting of the common, internal and external carotid arteries removed in 2013 when they discovered the tumor was wrapped around it during another neck dissection that was to involve intropaerative radiation, so they removed what they could, and sent me off from the recovery room to a sister hospital via ambulance that was highly regarded in neurology for testing to see if I was a candidate to have my left carotid artery totally removed. The testing consisted of a cervical angiogram, and a temporary balloon occlusion, some type of radiology scanning, maybe CT, and other blood work. I passed, and the next week I had my carotid removed, so I have no blood flow from the common carotid which branches off to the internal carotid and supplies the brain, and external that supplies the face, so all blood flow comes from the right side, which I have tested regularly for blockage with an ultrasound Doppler.
I did not have a vein graft reconstruction, and was having intraoperative radiation, IORT, during that surgery, which took about 5 hours, and a few weeks later did 25 Proton radiation, my 5th radiation type, and Carboplatin. I stood a chance of 17% of having a carotid artery blowout during proton radiation from all the radiation I had even though they were tied off stubs. All that treatment ended January 2014, and have been free of cancer since.
There are risks for adverse events with this operation. and even the testing, but I believe with testing there are fewer, but it's not always feasible to be done There is a time period after surgery when there is more risk for adverse events like fist day, 48hrs,,,..which I really forget, besides having lifetime risks.
Radiologic testing isn't always accurate for showing carotid involvement, and many wind up not needing the carotid artery removed.
Here is a medscape article about carotid artery involvement management:
http://emedicine.medscape.com/article/850738-overview