The spinal accessory nerve in head and neck surgery

To describe landmarks and tips used for minimizing surgical traumas to the spinal accessory nerve, and different options in case of its injury. Modified radical and selective neck dissections reduce the prevalence of shoulder syndrome, a sequela of radical neck dissection. Impaired shoulder mobility and pain may be present even after nerve-sparing procedures, as shown using electromyography, particularly when dissection is extended to level V. In these cases physical therapy is mandatory to prevent shoulder pain and functional limitations. The issue of spinal accessory nerve repair when macroscopically damaged or transected remains critical. Subclinical spinal accessory nerve impairment can be observed even after selective neck dissections (levels II-IV) due to routine clearance of sublevel IIB. Further studies should be performed to select patients in whom this sublevel could be left undissected without impairing oncologic radicality and to demonstrate if such a policy leads to better functional results. Early diagnosis of shoulder syndrome by questionnaires and clinical tests is recommended to appropriately plan physical therapy. Spinal accessory nerve repair is advocated to reduce the prevalence of shoulder syndrome after radical neck dissection. More data are needed to assess the superiority of newer techniques such as nerve transposition or bioresorbable nerve guides.