As far as neck dissections, there are several types, which remove or preserve certain structures. lymphs. I went in for a Modified Radical Neck Dissection, MRND, but due to prior radiation, everything was twisted around the lymph's, cancer, so a radical neck dissection, RND, had to be done on the spot, and that involves removal neck muscle, vein and nerve. In my last surgery, they removed the carotid artery, but had to remove other nerves, vagus nerve, along with it due to prior radiation. They never really know the extent until they get in there.