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.
Christoph J. Griessenauer, Joseph H. Miller, Bonita S. Agee, Winfield S. Fisher III, Joel K. Curé, Philip R. Chapman, Paul M. Foreman, Wilson A. M. Fisher, Adam C. Witcher and Beverly C. Walters
The aim of this study was to examine observer reliability of frequently used arteriovenous malformation (AVM) grading scales, including the 5-tier Spetzler-Martin scale, the 3-tier Spetzler-Ponce scale, and the Pollock-Flickinger radiosurgery-based scale, using current imaging modalities in a setting closely resembling routine clinical practice.
Five experienced raters, including 1 vascular neurosurgeon, 2 neuroradiologists, and 2 senior neurosurgical residents independently reviewed 15 MRI studies, 15 CT angiograms, and 15 digital subtraction angiograms obtained at the time of initial diagnosis. Assessments of 5 scans of each imaging modality were repeated for measurement of intrarater reliability. Three months after the initial assessment, raters reassessed those scans where there was disagreement. In this second assessment, raters were asked to justify their rating with comments and illustrations. Generalized kappa (κ) analysis for multiple raters, Kendall's coefficient of concordance (W), and interclass correlation coefficient (ICC) were applied to determine interrater reliability. For intrarater reliability analysis, Cohen's kappa (κ), Kendall's correlation coefficient (tau-b), and ICC were used to assess repeat measurement agreement for each rater.
Interrater reliability for the overall 5-tier Spetzler-Martin scale was fair to good (ICC = 0.69) to extremely strong (Kendall's W = 0.73) on initial assessment and improved on reassessment. Assessment of CT angiograms resulted in the highest agreement, followed by MRI and digital subtraction angiography. Agreement for the overall 3-tier Spetzler-Ponce grade was fair to good (ICC = 0.68) to strong (Kendall's W = 0.70) on initial assessment, improved on reassessment, and was comparable to agreement for the 5-tier Spetzler-Martin scale. Agreement for the overall Pollock-Flickinger radiosurgery-based grade was excellent (ICC = 0.89) to extremely strong (Kendall's W = 0.81). Intrarater reliability for the overall 5-tier Spetzler-Martin grade was excellent (ICC > 0.75) in 3 of the 5 raters and fair to good (ICC > 0.40) in the other 2 raters.
The 5-tier Spetzler-Martin scale, the 3-tier Spetzler-Ponce scale, and the Pollock-Flickinger radiosurgery-based scale all showed a high level of agreement. The improved reliability on reassessment was explained by a training effect from the initial assessment and the requirement to defend the rating, which outlines a potential downside for grades determined as part of routine clinical practice to be used for scientific purposes.
Ross L. Dawkins, Joseph H. Miller, Omar I. Ramadan, Michael C. Lysek, Elizabeth N. Kuhn, Brandon G. Rocque, Michael J. Conklin, R. Shane Tubbs, Beverly C. Walters, Bonita S. Agee and Curtis J. Rozzelle
There are many classification systems for injuries of the thoracolumbar spine. The recent Thoracolumbar Injury Classification and Severity Score (TLICS) has been shown to be a reliable tool for adult patients. The aim of this study was to assess the reliability of the TLICS system in pediatric patients. The validity of the TLICS system is assessed in a companion paper.
The medical records of pediatric patients with acute, traumatic thoracolumbar fractures at a single Level 1 trauma center were retrospectively reviewed. A TLICS was calculated for each patient using CT and MRI, along with the neurological examination recorded in the patient’s medical record. TLICSs were compared with the type of treatment received. Five raters scored all patients separately to assess interrater reliability.
TLICS calculations were completed for 81 patients. The mean patient age was 10.9 years. Girls represented 51.8% of the study population, and 80% of the study patients were white. The most common mechanisms of injury were motor vehicle accidents (60.5%), falls (17.3%), and all-terrain vehicle accidents (8.6%). The mean TLICS was 3.7 ± 2.8. Surgery was the treatment of choice for 33.3% of patients. The agreement between the TLICS-suggested treatment and the actual treatment received was statistically significant (p < 0.0001). The interrater reliability of the TLICS system ranged from moderate to very good, with a Fleiss’ generalized kappa (κ) value of 0.69 for the TLICS treatment suggestion among all patients; however, interrater reliability decreased when MRI was used to contribute to the TLICS. The κ value decreased from 0.73 to 0.57 for patients with CT only vs patients with CT/MRI or MRI only, respectively (p < 0.0001). Furthermore, the agreement between suggested treatment and actual treatment was worse when MRI was used as part of injury assessment.
The TLICS system demonstrates good interrater reliability among physicians assessing thoracolumbar fracture treatment in pediatric patients. Physicians should be cautious when using MRI to aid in the surgical decision-making process.