The radical neck dissection, RND, removes the sternocleidomadtoid muscle, the Spinal Assessory nerve, and the internal jugular vein. The modified radical neck dissection, MRND, removes the same lymph nodes, but preserves one or more of the non lymphatic structures, SCM, SAN, IJV. Seems like those with MRND preservation recover better with some of resulting surgery side effects than a RND that has all removed.