Anatomic study of the anastomoses between the superficial cervical plexus and the accessory spinal nerve

• Grant number: 13/02784-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2013
• End date: April 30, 2014
• Field of knowledge: Health Sciences - Medicine - Surgery
• Principal Investigator: Claudio Roberto Cernea
• Grantee: Viviane Passarelli Ramin Silva
• Host Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

In an anatomical study in cadavers, anastomoses of the accessory nerve (AN) were observed with branches of C2, C3, and C4. They concluded that the different clinical manifestations of injury AN were due to different anatomic patterns of motor innervation of the trapezius muscle. Other authors, however, have argued that the contribution of the cervical plexus is primarily proprioceptive, not participating significantly in the motor innervation of the trapezius muscle, in turn, reported that only a thin segment of AN innervated the upper trapezius, without any contribution of the plexus cervical. Another study, based on histological evaluation of the AN fibers removed from cadavers, concluded that the cervical plexus contributed to the motor innervation of the trapezius muscle. However, other authors have concluded that participation of the cervical plexus motor innervation of the trapezius muscle was not significant. Thus, it is discernible the controversy about the functional significance of the anastomoses between the AN and the cervical plexus. Despite these differences, it is recommended to preserve the AN and its anastomoses with the cervical plexus during neck dissections, whenever oncologically feasible to maintain the motor function of the trapezius muscle. It is, therefore, necessary to establish anatomical parameters that are useful for the Head and Neck Surgeon to locate the AN and its anastomoses. Objective the purpose of this study is to analyze the anatomic patterns of the anastomoses between the superficial cervical plexus roots and AN in a population of corpses without fixation, analyzing some measures of potential usefulness during a neck dissection. Methods this is an observational prospective non-randomized, examining 100 ANs and its anastomoses with the roots of the cervical plexus of 50 cadavers without fixation from both sexes submitted to autopsy at the Serviço de Verificação de Óbitos da Capital da Universidade de São Paulo (SVOC-USP) . It will be made an extended cervicothoracic flap to better expose the cervicothoracic region. The relation between the accessory nerve and the superficial cervical plexus roots are noted down, among other relationships. (AU)