Dysphagia and recurrent laryngeal nerve injury in anterior cervical discectomy and fusion

Abstract

Background: Cervical spine degenerative conditions effect up to two-thirds of the population and are the most common cause of acquired disability in patients over the age of 50. These disorders commonly present with axial pain, myelopathy, radiculopathy or a combination of these symptoms. Surgical intervention is generally indicated in with failure of conservative management or with evidence of cord compression or myelopathy. Anterior cervical discectomy and fusion (ACDF) is an effective option. It is not well established what factors contribute to dysphagia and recurrent laryngeal nerve palsy complications following ACDF surgery.

Objective: 1. To determine the rates of dysphagia and recurrent laryngeal nerve complications following ACDF reported in the literature and potential associated factors. 2. To determine rates of dysphagia and recurrent laryngeal nerve injuries in a large Australian series of ACDF by a single surgeon.

Methods: For the systematic reviews, electronic searches were performed using electronic databases. Relevant studies reporting the rate of dysphagia or recurrent laryngeal nerve injury as an endpoint for patients undergoing ACDF for degenerative disease, myelopathy, cervical canal stenosis or ossification of the posterior longitudinal ligament were identified according to prior inclusion and exclusion criteria. Statistical analysis was performed using odds ratio (OR) as the effective size. I2 was used to explore heterogeneity. For the retrospective chart review, consecutive patients undergoing ACDF from 2015 to 2019 for cervical radiculopathy and/or myelopathy were included. Univariate logistic regression analysis was performed to identify risk factors of RLN palsy, swallowing problems and adjacent-level ossification disease (ALOD).

Results and conclusions: We found that based on pooled analysis that there was a higher rate of dysphagia for multiple-level ACDF (6.6%) compared with single-level ACDF (4%). The pooled incidence of recurrent laryngeal nerve palsy from the literature was 1.2%, with no difference between multiple- and single-level ACDF. These rates were similar to analysis of our retrospective series, with 1.8% patients having recurrent laryngeal nerve palsy and 4.0% with clinical dysphagia. We confirm based on our series that multi-level operation was associated with higher rate of RLN palsy, but this was not affected by other factors including age, gender, and the use of plate, internal fixation or number of screws.