The prevalence of nerve injuries following neck dissections - a systematic review and meta-analysis

Introduction: Symptoms of the shoulder syndrome (SS) and spinal accessory nerve (SAN) impairments are well-known complications to any neck dissections (NDs). Even so, their prevalence is reported with large variations in the literature. Furthermore, marginal mandibular nerve (MMN) injuries are claimed to be underreported. The purpose of this study was to investigate the prevalence of SS, SAN and MMN injuries after different types of ND. Methods: This systematic review and meta-analysis included studies reporting SAN and MMN injuries following the three main types of ND. Pooled estimates of the prevalence were made by the main types of ND with 95% confidence intervals (95% CI). Results: Nineteen studies reported a total of 457 SAN injuries. The estimated prevalence of SS or SAN injuries following radical neck dissection, modified radical neck dissection and selective neck dissection was 94.8% (95% CI: 88.5-98.9%), 33.0% (95% CI: 19.4-48.3%) and 27.9% (95% CI: 7.1-54.5%), respectively. Five studies reported a total of 64 MMN injuries. The estimated prevalence following modified radical neck dissection and selective neck dissection was 13.1% (95% CI: 0-37.6%) and 12.7% (95% CI: 4.3-24.1%), respectively. Conclusions: This meta-analysis estimated a high prevalence of SS, SAN and MMN injuries following the three main types of ND. If oncological considerations allow it, the less morbid ND should be considered. MMN injuries have only been reported in a limited number of small studies. The results may be used to compare future research and as guidance for quality evaluation within departments.