Modifications of neck dissection
The original operation of radical neck dissection has stood the test of time, but in the last 20 years modifications of neck dissection have been designed to try to reduce the adverse effects of the operation. The simplest modification, which is essential if bilateral neck dissections are to be performed simultaneously, is to conserve the internal jugular vein by dissecting the tumour-bearing lymph nodes from its surface, in the same way as they are dissected from the common carotid artery. Another modification, applicable in cases of tumour not directly related to the accessory nerve, is to dissect out that nerve through the posterior triangle of the neck and the sternomastoid muscle and conserve it, thus preserving function of the trapezius muscle and shoulder. Some surgeons prefer to try to identify branches running from the cervical plexus of nerves into the muscle, which are believed to provide an accessory nerve supply. Other, named, modifications are discussed in the next two sections.