Matthew S. Erwood, Mark N. Hadley, Amber S. Gordon, William R. Carroll, Bonita S. Agee and Beverly C. Walters
Recurrent laryngeal nerve (RLN) injury is one of the most frequent complications of anterior cervical discectomy and fusion (ACDF) procedures. The frequency of RLN is reported as 1%–11% in the literature.4,15 The rate of palsy after reoperative ACDF surgery is not well defined. This meta-analysis was performed to review the current medical evidence on RLN injury after ACDF surgery and to determine a relative rate of RLN injury after reoperative ACDF.
MEDLINE, PubMed, and Google Scholar searches were performed using several key words and phrases related to ACDF surgery. Included studies were written in English, addressed revisionary ACDF surgery, and studied outcomes of RLN injury. Statistical analysis was then performed using a random-effects model to calculate a pooled rate of RLN injury. The heterogeneity of the studies was assessed using Cochran's Q statistic and I2 statistic, and a funnel plot was constructed to evaluate publication bias.
The search initially identified 345 articles on this topic. Eight clinical articles that met all inclusion criteria were included in the meta-analysis. A total of 238 patients were found to have undergone reoperative ACDF. Thirty-three of those patients experienced an RLN injury. This analysis identified a rate of RLN injury in the literature after reoperative ACDF of 14.1% (95% confidence interval [CI] 9.8%–19.1%).
The rate of RLN palsy of 14.1% was greater than any published rate of RLN injury after primary ACDF operations, suggesting that there is a greater risk of hoarseness and dysphagia with reoperative ACDF surgeries than with primary procedures as reported in these studies.
Matthew S. Erwood, Beverly C. Walters, Timothy M. Connolly, Amber S. Gordon, William R. Carroll, Bonita S. Agee, Bradley R. Carn and Mark N. Hadley
Dysphagia and vocal cord palsy (VCP) are common complications after anterior cervical discectomy and fusion (ACDF). The reported incidence rates for dysphagia and VCP are variable. When videolaryngostroboscopy (VLS) is performed to assess vocal cord function after ACDF procedures, the incidence of VCP is reported to be as high as 22%. The incidence of dysphagia ranges widely, with estimates up to 71%. However, to the authors’ knowledge, there are no prospective studies that demonstrate the rates of VCP and dysphagia for reoperative ACDF. This study aimed to investigate the incidence of voice and swallowing disturbances before and after reoperative ACDF using a 2-team operative approach with comprehensive pre- and postoperative assessment of swallowing, direct vocal cord visualization, and clinical neurosurgical outcomes.
A convenience sample of sequential patients who were identified as requiring reoperative ACDF by the senior spinal neurosurgeon at the University of Alabama at Birmingham were enrolled in a prospective, nonrandomized study during the period from May 2010 until July 2014. Sixty-seven patients undergoing revision ACDF were enrolled using a 2-team approach with neurosurgery and otolaryngology. Dysphagia was assessed both preoperatively and postoperatively using the MD Anderson Dysphagia Inventory (MDADI) and fiberoptic endoscopic evaluation of swallowing (FEES), whereas VCP was assessed using direct visualization with VLS.
Five patients (7.5%) developed a new postoperative temporary VCP after reoperative ACDF. All of these cases resolved by 2 months postoperatively. There were no new instances of permanent VCP. Twenty-five patients had a new swallowing disturbance detected on FEES compared with their baseline assessment, with most being mild and requiring no intervention. Nearly 60% of patients showed a decrease in their postoperative MDADI scores, particularly within the physical subset.
A 2-team approach to reoperative ACDF was safe and effective, with no new cases of VCP on postoperative VLS. Dysphagia rates as assessed through the MDADI scale and FEES were consistent with other published reports.