Dysphagia and Dysphonia Assessment Tools After Anterior Cervical Spine Surgery

A Novel Method for Tracking Neck Motions Using a Skin-Conformable Wireless Accelerometer: A Pilot Study

Introduction

Cervical spine disease is a leading cause of pain and disability. Degenerative conditions of the spine can result in neurologic compression of the cervical spinal cord or nerve roots and may be surgically treated with an anterior cervical discectomy and fusion (ACDF) in up to 137,000 people per year in the United States. A common sequelae of ACDF is reduced cervical range of motion (CROM) with patient-based complaints of stiffness and neck pain. Currently, tools for assessment of CROM are manual, subjective, and only intermittently utilized during doctor or physical therapy visits. We propose a skin-mountable acousto-mechanic sensor (ADvanced Acousto-Mechanic sensor; ADAM) as a tool for continuous neck motion monitoring in postoperative ACDF patients. We have developed and validated a machine learning neck motion classification algorithm to differentiate between eight neck motions (right/left rotation, right/left lateral bending, flexion, extension, retraction, protraction) in healthy normal subjects and patients.

Methods

Sensor data from 12 healthy normal subjects and 5 patients were used to develop and validate a Convolutional Neural Network (CNN).

Results

An average algorithm accuracy of 80.0 ± 3.8% was obtained for healthy normal subjects (94% for right rotation, 98% for left rotation, 65% for right lateral bending, 87% for left lateral bending, 89% for flexion, 77% for extension, 50% for retraction, 84% for protraction). An average accuracy of 67.5 ± 5.8% was obtained for patients.

Discussion

ADAM, with our algorithm, may serve as a rehabilitation tool for neck motion monitoring in postoperative ACDF patients. Sensor-captured vital signs and other events (extubation, vocalization, physical therapy, walking) are potential metrics to be incorporated into our algorithm to offer more holistic monitoring of patients after cervical spine surgery.

Evaluation of outcome measures for post-operative dysphagia after anterior cervical discectomy and fusion

PURPOSE

The goal is to conduct a review of the current literature to determine and evaluate the current classification metrics available for quantifying post-operative dysphagia.

METHODS

We surveyed the literature for the subjective and objective measures used to classify dysphagia, and further described and analyzed them in the context of post-operative dysphagia (PD) after anterior cervical spine surgery, with a focus on anterior cervical discectomy and fusion (ACDF). We searched PubMed from the years 2005-2021 using the terms "anterior cervical discectomy and fusion" and "dysphagia or postoperative dysphagia." We included papers that were meta-analyses, systemic reviews, prospective, or retrospective studies. Our selection was further consolidated via abstract and title screening. Ultimately, nineteen articles were included and had full-text reviews.

RESULTS

EAT-10 tool was shown to be more valid and reliable than the commonly used Bazaz grading system. HSS-DDI was found to have a high diagnostic accuracy in stratifying mild, moderate, and severe PD. A shortened 16-item version of the original 44-item SWAL-QOL was found to be statistically and clinically significant. When compared to PROMs, objective tests more accurately diagnose PD.

CONCLUSION

We found that the most valuable subjective tests were the EAT-10 and HSS-DI because they are quick, sensitive, and correlated strongly with the well-established measurements of PD. The MBS and FEES provided accurate measurements of the severity of PD, but they required more time and equipment than the surveys. In some patient populations, such as those with pre-surgical dysphagia, objective testing should always be done.

International and Multicenter Prospective Controlled Study of Dysphagia After Anterior Cervical Spine Surgery

BACKGROUND

In the context of anterior approach to the cervical spine, dysphagia is a common complication and still without a clear distinction of risk factors.

OBJECTIVE

To analyze the risk factors of dysphagia after cervical spine surgery.

METHODS

Multicenter prospective study evaluated patients who underwent anterior cervical spine surgery for degenerative pathologies, studying surgical, anesthesia, base disease, and radiological variables (preoperatively, 24 hours, 1 and 3 weeks, and 6 months after surgery), with control group matched. Postoperative dysphagia was assessed by Swallowing Satisfaction Index and Swallowing Questionnaire; besides, based on multiple logistic regression model, a risk factor analysis correlation was applied.

RESULTS

In total, 233 cervical patients were evaluated; most common level approached was C5-C6 (71.8%). All showed same decreasing trade for dysphagia incidence-with more cases on cervical group ( P < .05); severe cases were rare. At postoperative day 1, identified risk factors were approach to C3-C4 (4.11, P < .01), loss of preoperative cervical lordosis (2.26, P < .01), intubation attempts ≥2 (3.10, P < .01), and left side approach (1.85, P = .02); at day 7, body mass index ≥30 (2.29, P = .02), C3-C4 (3.42, P < .01), and length of surgery ≥90 minutes (2.97, P = .005); and at day 21, C3-C4 were kept as a risk factor (3.62, P < .01).

CONCLUSION

A high incidence level of dysphagia was identified, having a clear decreasing trending (number of cases and severity) through postoperative time points; considering possible risk factors, strongest correlation was the approach at the C3-C4 level-statistically significant at the 24 hours, 7 days, and 21 days assessment.

A scoping review of the methods used to capture dysphagia after anterior cervical discectomy and fusion: the need for a paradigm shift

OBJECTIVE

Dysphagia is the most commonly reported complication of annterior cervical discectomy and fusion (ACDF) surgery. However, the incidence of dysphagia post-ACDF varies widely-partly attributable to differing outcome measures used to capture dysphagia. Our objective was to conduct a scoping review of the literature to quantify which dysphagia outcome measures have been employed post-ACDF and examine trends by study design, year, and location.

METHODS

After removing duplicates, 2396 abstracts were screened for inclusion. A total of 480 studies were eligible for full-text review. After applying exclusion criteria, data was extracted from 280 studies. We extracted the dysphagia outcome measure(s), study design (prospective vs retrospective), year, and location (country). Approximately 10% of studies were repeated for intra-rater agreement.

RESULTS

In total, 317 dysphagia outcome measures were reported in 280 studies (primarily retrospective-63%). The largest proportion of outcome measures were categorized as "unvalidated patient-reported outcome measures" (46%), largely driven by use of the popular Bazaz scale. The next most common categories were "insufficient detail" and "validated patient-reported outcome measures" (both 16%) followed by "chart review/database" (13%) and instrumental assessment (7%). Studies examining dysphagia post-ACDF steadily increased over the years and the use of validated measures increased in the past 10 years.

CONCLUSIONS

This scoping review of the literature highlights that nearly half of the ACDF dysphagia literature relies on unvalidated patient-reported outcome measures. The current understanding of the mechanism, timeline, and presentation of dysphagia post-ACDF are likely limited due to the metrics that are most commonly reported in the literature.

Impact of local steroid application on dysphagia after anterior cervical spine surgery: a meta-analysis

INTRODUCTION

Dysphagia is one of the most common complications of anterior cervical spine surgery. Local steroid was widely used to reduce the postoperative swallowing pain. However, the effect of local steroid application on dysphagia after anterior cervical spine surgery was still uncertain.

MATERIALS AND METHODS

We searched Medline (PubMed), Embase and the Cochrane Library on July 27, 2021 for studies investigating the effect of local steroid application on dysphagia after anterior cervical spine surgery from their date of inception to 2021. The relative risk or weighted mean difference with 95% confidence interval was recorded as a summary statistic consist of postoperative dysphagia, swallowing VAS scores, SWAL-QOL scores, PSTSI, and steroid related complications.

RESULTS

This meta-analysis included 7 RCT studies involving 254 patients in the steroid group and 232 patients in the placebo group. Results showed local steroid group had less patients with dysphagia, lower swallowing VAS scores and less severe of prevertebral soft-tissue edema on the fourth day after surgery. No significant difference in non-fusion rate between the two groups was observed. And all included studies had no serious steroid related complications reported.

CONCLUSIONS

The use of local steroid in anterior cervical spine surgery could reduce the early postoperative dysphagia without serious steroid related complication. However, the safety of local steroid application still need further studies with larger samples.

Ramifications of Postoperative Dysphagia on Health Care Resource Utilization Following Elective Anterior Cervical Discectomy and Interbody Fusion for Cervical Spondylotic Myelopathy

STUDY DESIGN

This is a retrospective cohort study.

OBJECTIVE

The aim of this study was to investigate patient risk factors and health care resource utilization associated with postoperative dysphagia following elective anterior cervical discectomy and fusion (ACDF) for cervical spondylotic myelopathy.

SUMMARY OF BACKGROUND DATA

There is a paucity of data on factors predisposing patients to dysphagia and the burden this complication has on health care resource utilization following ACDF.

METHODS

A retrospective cohort study was performed using the Nationwide Inpatient Sample (NIS) database from 2016 to 2017. All adult (above 18 y old) patients undergoing ACDF for cervical spondylotic myelopathy were identified using the ICD-10-CM diagnosis and procedural coding system. Patients were then categorized by whether they had a recorded postoperative dysphagia or no dysphagia. Weighted patient demographics, comorbidities, perioperative complications, length of hospital stay (LOS), discharge disposition, and total cost of admission were assessed. A multivariate stepwise logistic regression was used to determine both the odds ratio for risk-adjusted postoperative dysphagia as well as extended LOS.

RESULTS

A total of 17,385 patients were identified, of which 1400 (8.1%) experienced postoperative dysphagia. Compared with the No-Dysphagia cohort, the Dysphagia cohort had a greater proportion of patients experiencing a complication (P=0.004), including 1 complication (No-Dysphagia: 2.9% vs. Dysphagia: 6.8%), and >1 complication (No-Dysphagia: 0.3% vs. Dysphagia: 0.4%). The Dysphagia cohort experienced significantly longer hospital stays (No-Dysphagia: 1.9±2.1 d vs. Dysphagia: 4.2±4.3 d, P<0.001), higher total cost of admission (No-Dysphagia: $19,441±10,495 vs. Dysphagia: $25,529±18,641, P<0.001), and increased rates of nonroutine discharge (No-Dysphagia: 16.5% vs. Dysphagia: 34.3%, P<0.001). Postoperative dysphagia was found to be a significant independent risk factor for extended LOS on multivariate analysis, with an odds ratio of 5.37 (95% confidence interval: 4.09, 7.05, P<0.001).

CONCLUSION

Patients experiencing postoperative dysphagia were found to have significantly longer hospital LOS, higher total cost of admission, and increased nonroutine discharge when compared with the patients who did not.

LEVEL OF EVIDENCE

Level III.

Characterization of dysphagia following anterior cervical spine surgery

BACKGROUND

Post-operative dysphagia is one of the most common complications of anterior cervical spine surgery (ACSS).

OBJECTIVE

Examine post-operative structural and physiologic swallowing changes in patients with dysphagia following ACSS as compared with healthy age and gender matched controls.

METHODS

Videofluoroscopic swallow studies of adults with dysphagia after ACSS were retrospectively reviewed. Seventy-five patients were divided into early (≤2 months) and late (> 2 months) post-surgical groups. Modified Barium Swallow Impairment Profile (MBSImP), Penetration-Aspiration Scale (PAS) scores, and pharyngeal wall thickness (PWT) metrics were compared.

RESULTS

Significant differences were identified for all parameters between the control and early post-operative group. MBSImP Pharyngeal Total (PT) scores were greater in the early group (Interquartile Range (IQR) = 9-14, median = 12) versus controls (4-7, 5, P < 0.001) and late group (0.75-7.25, 2, P < 0.001). The early group had significantly higher maximum PAS scores (IQR = 3-8, median = 7) than both the control group (1-2, 1, P < 0.001) and late post-operative group (1-1.25, 1, P < 0.001). PWT was significantly greater in the early (IQR = 11.12-17.33 mm, median = 14.32 mm) and late groups (5.31-13.01, 9.15 mm) than controls (3.81-5.41, 4.68 mm, P < 0.001).

CONCLUSION

Dysphagic complaints can persist more than two months following ACSS, but often do not correlate with validated physiologic swallowing dysfunction on VFSS. Future studies should focus on applications of newer technology to elucidate relevant deficits.

Workers' Compensation Status in Association with a High NDI Score Negatively Impacts Post-Operative Dysphagia and Dysphonia Following Anterior Cervical Fusion

BACKGROUND

Anterior cervical discectomy and fusion (ACDF) is a safe and effective procedure but has approach-related complications like postoperative dysphagia and dysphonia (PDD). Patient-reported outcome measures including the Hospital for Special Surgery Dysphagia and Dysphonia Inventory (HSS-DDI) have been used for the assessment of PDD. Various factors have been described that affect ACDF outcomes, and our aim was to investigate the effect of workers' compensation (WC) status.

METHODS

We included patients who underwent ACDF from 2015 to 2018 stratified according to insurance status: WC/non-WC. PDDs were assessed using the HSS-DDI score. We conducted logistic regression analyses. Statistical significance was set at P < 0.05.

RESULTS

We included 287 patients, 44 (15.33%) WC and 243 (84.67%) non-WC. A statistical comparison revealed a clinically relevant difference in the HSS-DDI total score and both subdomains (P = 0.015; dysphagia P = 0.021; dysphonia P = 0.002). Additional logistic regression analysis adjusting for preoperative Neck Disability Index scores resulted in no clinically relevant differences in the HSS-DDI total score and both subdomains (total score P = 0.420; dysphagia P = 0.531; dysphonia 0.315).

CONCLUSIONS

WC status was associated with a worse HSS-DDI score but could not be shown to be an independent risk factor for PDD. The preoperative NDI score was a strong predictor for PDD with a clinically relevant difference in the HSS DDI score (P < 0.0001). Surgeon awareness of risk factors for PDD such as WC status, even if it could not be shown as independent, is important as it may influence surgical decision making and managing patient expectations.

Effect of Topical Steroid on Swallowing Following ACDF: Results of a Prospective Double-Blind Randomized Control Trial

STUDY DESIGN

Randomized, double-blinded, controlled trial.

OBJECTIVE

To investigate the effectiveness of local intraoperative corticosteroids at decreasing the severity of swallowing difficulty following multilevel anterior cervical discectomy and fusion (ACDF).

SUMMARY OF BACKGROUND DATA

Dysphagia is a common complication after ACDF, and while for most patients the symptoms are mild and transient, some patients can suffer from severe dysphagia resulting in significant postoperative morbidity. Previous studies investigating the local application of corticosteroids are limited.

METHODS

This was a prospective, randomized, double-blinded, controlled trial of patients undergoing 2, 3, or 4 level ACDF for radiculopathy and/or myelopathy. Patients undergoing multilevel ACDF were randomized to receive local corticosteroid in the retropharyngeal space or placebo (no steroid). Dysphagia was assessed using validated outcomes including the Eating Assessment Tool-10 (Eat-10) and Swallowing Quality of Life (SWAL-QOL) Questionnaire both preoperatively and at 1 day (POD1), 2 days (POD2), and 1-month postoperatively.

RESULTS

One-hundred nine patients had a complete dataset available for analysis. Eat-10 scores were significantly lower in the Steroid group on POD2 (8 vs. 16, P = 0.03) and 1-month postoperatively (2 vs. 5, P = 0.03). A comparison of the individual SWAL-QOL subscale scores demonstrated that patients in the Steroid group had better scores than the Control group in various subscales at all postoperative time points. Significant differences were noted (always in favor of the Steroid group) in 40% of subscales on POD1, 60% of subscales on POD2, and 50% of subscales at 1-month postoperatively. The Control group never had a better SWAL-QOL subscale score at any time point postoperatively.

CONCLUSION

Local administration of corticosteroid after multilevel ACDF can decrease postoperative severity and symptomatology of dysphagia during the immediate postoperative period to 1-month postoperatively. The long-term effects of local steroid administration on fusion and other complications will need to be established in future studies.Level of Evidence: 1.

Comparison of Bazaz scale, Dysphagia Short Questionnaire, and Hospital for Special Surgery-Dysphagia and Dysphonia Inventory for Assessing Dysphagia Symptoms After Anterior Cervical Spine Surgery in Chinese Population

Dysphagia is one of the most common complaints after anterior cervical spine surgery. The Bazaz scale, the Dysphagia Short Questionnaire (DSQ), and the Hospital for Special Surgery-Dysphagia and Dysphonia Inventory (HSS-DDI) were patient-reported outcome measures assessing the patients' perceptions of their swallowing functions after surgery. This prospective diagnostic test study aimed to compare these surveys' psychometric properties in the Chinese population. We evaluated 150 consecutive patients after anterior cervical spine surgery with the Bazaz scale, DSQ, HSS-DDI, and M.D. Anderson Dysphagia Inventory (MDADI). The reliability and validity of the Bazaz scale, DSQ, and HSS-DDI were compared. Receiver operating characteristic (ROC) curves of the DSQ, Bazaz scale, and HSS-DDI were constructed using the MDADI as a reference criterion. Their areas under the curve (AUCs) were further analyzed. In total, 132 participants completed all of the surveys. The results showed that all surveys were significantly correlated with each other. The HSS-DDI and HSS-Dysphagia subscale showed near-perfect reliability (Cronbach α = 0.969 and 0.957, respectively). ROC curves showed both HSS-DDI and HSS-Dysphagia subscale had greater accuracy (AUCs > 0.9) in detecting mild dysphagia and moderate/severe dysphagia. The HSS-Dysphagia subscale achieved higher accuracy in assessing the dysphagia symptoms after anterior cervical spine surgery. The Bazaz scale was considered less accurate than other scales. Our results provided guidance for selecting the appropriate measuring tool during clinical and research practices.

Preliminary outcomes of allograft and hydroxyapatite as substitutes for autograft in anterior cervical discectomy and fusion with self-locking standalone cages

Purpose

To investigate the efficacy and safety of allograft and hydroxyapatite (HA) as substitutes for autograft in anterior cervical discectomy and fusion (ACDF).

Methods

In this study, 49 patients (80 segments) treated with ACDF were included and allocated into three groups [group A, autogenous iliac bone, n = 18; group B, allogeneic bone, n = 16; group C, HA, n = 15]. The clinical efficacy and fusion status were compared among each group. Complications were recorded in detail, and the Bazaz classification and Voice Handicap Index-10 (VHI-10) were used to detect dysphagia and dysphonia.

Results

Patients exhibited similar clinical efficacy among the groups during the final follow-up. All patients in groups A and B achieved fusion compared to only 73.3% of patients in group C. Groups A and B had similar fusion score, both of which greater than that of group C. No cage subsidence was observed in group A; however, 6.3% of patients in group B and 53.3% in group C had cage subsidence. Two patients in group A (11.1%) had persistent pain at the donor site. One patient in group B had dysphagia and dysphonia (6.3%), while one patient in group C had dysphonia (6.7%).

Conclusion

In ACDF, the autogenous iliac bone was the most ideal bone graft. The allogeneic bone was an acceptable substitute but risked cage subsidence and dysphagia. HA had a much lower fusion rate and a high risk of cage subsidence. Better substitutes should be further explored for ACDF.

Hyoid position as a novel predictive marker for postoperative dysphagia and dysphonia after anterior cervical discectomy and fusion

PURPOSE

The purpose of this study is to investigate the predictive value of the hyoid horizontal positional change on the severity of dysphagia and dysphonia (PDD) after anterior cervical discectomy and fusion (ACDF) comparing pre-vertebral soft-tissue thickness (PVST).

METHODS

This is a retrospective observational study with prospectively collected data at a single academic institution. ACDF patients between 2015 to 2018 who had complete self-reported PDD surveys and pre- and postoperative lateral cervical radiographs were included in the analysis. PDD was assessed utilizing the Hospital for Special Surgery Dysphagia and Dysphonia Inventory (HSS-DDI). The hyoid-vertebral distance (HVD) and PVST (the averages of C2 to C7 levels (PVSTC2-7) and all operating levels (PVSTOP)) were assessed preoperatively and upon discharge. The associations among postoperative changes of HVD, PVSTs, and the 4-week HSS-DDI score were evaluated.

RESULTS

Of the 268 patients with a HSS-DDI score assessment, 209 patients had complete data. In univariate analyses, HVD and PVSTC2-7 changes demonstrated significant correlations with HSS-DDI, whereas PVSTOP showed no significant association. After adjusting with sex and operating level, the changes in HVD (p = 0.019) and PVSTC2-7 (p = 0.009) showed significant associations with the HSS-DDI score and PVSTOP showed no significant association. PVSTC2-7 could not be evaluated in 12% of patients due to measurement difficulties of PVST at lower levels.

CONCLUSION

We introduce a novel potential predictive marker for PDD after ACDF. Our results suggest that HVD can be utilized for the risk assessment of PDD, especially in PVST unmeasurable cases, which accounts for over 10% of ACDF patients.

Effect of Tracheal Intubation Mode on Cuff Pressure During Retractor Splay and Dysphonia Recovery After Anterior Cervical Spine Surgery: A Randomized Clinical Trial

MINI: This randomized clinical trial showed different intubation mode in anesthesia did not affect the increase of endotracheal cuff pressure caused by the retractor splay in anterior cervical spine surgery. However, nasotracheal intubation improved postoperative dysphonia recovery after anterior cervical spine surgery.

STUDY DESIGN

Prospective, randomized, double-blinded trial.

OBJECTIVE

The aim of this study was to investigate whether the mode of tracheal intubation affects intraoperative endotracheal tube cuff pressure on retractor splay and post-anterior cervical spine surgery (ACSS) voice outcome.

SUMMARY OF BACKGROUND DATA

The combination of endotracheal tube (ETT) and cervical retractors has been implicated in recurrent laryngeal nerve compression and neuropraxia after ACSS. The asymmetric position of the oroETT within the larynx, as being fixed distally by the cuff and proximally by taping on one side of the mouth, may contribute to unilateral vocal palsy.

METHODS

Adult patients undergoing ACSS were randomized to receive either nasotracheal or orotracheal intubation under anesthesia. The primary endpoint was the maximal endotracheal tube cuff pressure (ETCP) when the retractors were set up. After the maximal ETCPs were recorded, then ETCPs were controlled to less than 25 mmHg. Secondary endpoints were self-assessed hoarseness, pitch, and loudness of voice on postoperative days (PODs) 1, 2, 7, and 30.

RESULTS

We equally allocated 110 patients to nasotracheal and orotracheal intubation. The maximal ETCP during retractor splay did not differ for both the means and distributions of pressure range. After the surgery, more patients in the nasotracheal intubation group reported none or mild change of voice than did the orotracheal intubation group on PODs 1 and 2, in terms of hoarseness, pitch, and loudness (P = 0.001, 0.001, and 0.005, respectively, on POD 1; P = 0.002, 0.003, and 0.011, respectively, on POD 2). Mixed model analysis demonstrated that patients with nasotracheal intubation had significantly lower dysphonia scores after surgery (estimate treatment effect: -1.62, P < 0.0001). Statistics was adjusted to exclude interaction with ETT sizes.

CONCLUSION

The tracheal intubation modes did not affect ETCP during retractor splay. However, nasotracheal intubation had a beneficial effect on dysphonia recovery after ACSS.

LEVEL OF EVIDENCE

2.

Risk Factors and Assessment Using an Endoscopic Scoring System for Early and Persistent Dysphagia After Anterior Cervical Decompression and Fusion Surgery

STUDY DESIGN

Prospective study.

OBJECTIVES

Preoperative and postoperative dysphagia was evaluated by an otolaryngology doctor and a speech-language-hearing therapist using the eating assessment tool (EAT-10) and Hyodo-Komagane scores. The objective was to achieve a more precise evaluation of the incidence and risk factors of early and persistent dysphagia after anterior cervical discectomy and fusion (ACDF).

SUMMARY OF BACKGROUND DATA

Although numerous reports have explored the risk factors for dysphagia after ACDF, these factors remain controversial. The main reason for this situation is that the methods for evaluating dysphagia are not adequate or uniform.

MATERIALS AND METHODS

This study involved a retrospective 47 consecutive patients who had undergone ACDF and been followed up for at least 1 year. Sagittal alignment of the cervical spine was evaluated by a preoperative x-ray. Univariate and multivariate logistic regression analyses were performed to determine risk factors for transient or persistent dysphagia.

RESULTS

The study showed that 34% of patients developed dysphagia in the early postoperative period and that 25.5% of patients still had persistent dysphagia 1 year postoperatively. 8.5% of patients had already developed dysphagia preoperatively, with a significant positive correlation observed between preoperative and postoperative dysphagia.Aging and smoking were significant risk factors for transient dysphagia. A preoperative cervical kyphotic angle at the C3/C4, C4/C5 disk-level and change in the kyphotic angle at C4/C5 during surgery were significant risk factors of persistent dysphagia 1 year after surgery.

CONCLUSIONS

This is the first study to show dysphagia after anterior cervical spine surgery using the EAT-10 score and Hyodo-Komagane score with endoscopic evaluation. Aging and smoking were significant risk factors for transient dysphagia, while preoperative local kyphosis angles of C3-C4 and C4-C5 and change in the kyphotic angle at C4/C5 during surgery may be a key alignment of risk factors for postoperative persistent dysphagia.

LEVEL OF EVIDENCE

Level: III.

An Eight-Year Follow-Up Study on the Treatment of Single-Level Cervical Spondylosis Through Intervertebral Disc Replacement and Anterior Cervical Decompression and Fusion

Objective

To compare the efficacy and safety of the postoperative long‐term effect of the treatment of single‐level cervical spondylosis through anterior cervical discectomy and fusion (ACDF) and artificial cervical disc replacement (ACDR).

Methods

This is a retrospective contrastive study, which was conducted for the period of January 2007 and January 2009 at the Department of Spine Surgery of the First Affiliated Hospital of Xinjiang Medical University. A total of 113 patients were divided into two groups depending on the operation method: ACDF group (fusion group, n = 66) and ACDR group (replacement group, n = 47). The ACDR group comprised of 23 males and 24 females. The age of these patients ranged from 31–60 years, with an average age of 42.89 ± 6.30 years. The ACDF group comprised of 38 males and 28 females. The age of these patients ranged from 28–73 years old, with an average age of 49.38 ± 9.89 years old. The evaluation index included the visual analogue scale (VAS), neck disability index (NDI), range of motion, dysphagia, adjacent vertebral disease, and related complications (prosthesis displacement, heterotopic ossification, etc.).

Results

A total of 113 patients met the inclusion criteria, and these patients receive more than 96 months of follow‐up. The VAS and NDI of these two groups of patients significantly improved, when compared with those before the operation. In the last follow‐up visit, the range of motion in the ACDR group and ACDF group was 43.22 ± 3.58 and 32.54 ± 2.82, respectively, and both are significantly different comparing to the values measured before the operation (P < 0.05). The dysphagia incidence of the ACDR group was higher than that of the ACDF group at the 36th month, but was lower than that of the ACDF group in other points time. In the last follow‐up visit, six patients (12.77%) in the ACDR group and 18 patients (27.27%) in the ACDF suffered from adjacent segment degeneration (ASD). The general complication rate in the replacement group and fusion group was 38.31% and 37.88%, respectively, but the difference between the two groups was not statistically significant (P > 0.05).

Conclusion

Overall, the clinical efficacy and related complication rate of single‐level cervical spondylosis after an anterior cervical approach operation was superior in the ACDR group when compared to the ACDF group.

Association Between the Severity of Dysphagia and Various Parameters of the Cervical Spine; Videofluoroscopic Analysis in Neutral and Retraction Position of the Normal Volunteers

STUDY DESIGN

Videoflurographic swallowing study in asymptomatic volunteers.

OBJECTIVE

The purpose of this study was to investigate the relationship between the severity of dysphagia and various parameters of the subjects.

SUMMARY OF BACKGROUND DATA

Occipitocervical fixation is associated with several potential complications. Malalignment of craniovertebral junction and associated dysphagia have been well described in the literature. However, there has been little attention given to investigate the association between the degree of swallowing dysfunction and various patient's parameters.

METHODS

Thirty-nine healthy asymptomatic volunteers, 18 males and 21 females, were enrolled in this study. Based on videofluorographic swallowing study (VFSS), two scoring systems of swallowing dysfunction (dysphagia rating scale [DRS], dysphagia outcome and severity scale [DOSS]) were measured in neutral and retraction position. Multiple linear regression analysis was performed to evaluate the relationship between the degree of swallowing dysfunction and various factors of the subjects such as radiological and clinical parameters.

RESULTS

There was statistically significant correlation between DRS and DOSS (r = -0.354, P < 0.05). Multiple regression analysis showed that there was a significant association of the dysphagia severity (DRS and DOSS) with the percentile change of the narrowest oropharyngeal diameter (OD) (%dn OD) (r = 0.121, P < 0.01 and r = 0.020, P < 0.01, respectively). Percentile change of OD (neutral and retraction position) was positively associated with the difference of C0-2 angle (r = 1.676, P < 0.01). None of the other variables such as age, sex, C0-1 angle, C1-2 angle, and C2-7 angle were significantly associated with the degree of dysphagia or %dn OD.

CONCLUSION

This study demonstrated that the severity of dysphagia is significantly associated with the percentile change of OD and the C0-2 angle has considerable effect on the OD after O-C fusion. Therefore, C0-2 angle could be the most critical radiological parameter not only for predicting the stricture of oropharyngeal space but also for preventing postoperative dysphagia.

LEVEL OF EVIDENCE

4.

The Effects of Perioperative Corticosteroids on Dysphagia Following Surgical Procedures Involving the Anterior Cervical Spine: A Prospective, Randomized, Controlled, Double-Blinded Clinical Trial

BACKGROUND

Dysphagia is one of the most common complications of surgical procedures in the anterior cervical spine, and can persist up to 2 years postoperatively. Corticosteroids are relatively safe and inexpensive for treating various inflammatory conditions. Perioperative corticosteroid administration for anterior cervical spine procedures may effectively minimize postoperative dysphagia, potentially leading to better outcomes, decreased readmission rates, and improved patient satisfaction. The purpose of this study was to determine the efficacy of perioperative corticosteroids in decreasing the severity and duration of dysphagia following single-level and multilevel anterior cervical spine procedures.

METHODS

Seventy-four patients undergoing elective anterior cervical surgical procedures for degenerative conditions were recruited. Patients with prior cervical procedures; with a diagnosis of fracture, malignancy, or infection; or requiring combined anterior-posterior procedures were excluded. Patients were randomized to perioperative intravenous dexamethasone or saline solution. Doses were administered before incision and at 8 and 16 hours postoperatively. Investigators and patients were blinded to the treatment throughout the study. Dysphagia outcomes were assessed with use of the Bazaz dysphagia scale and the Dysphagia Short Questionnaire (DSQ) at 1 day, 2 days, 1 week, 2 weeks, 1 month, 3 months, 6 months, and 12 months postoperatively. Statistical analysis was performed comparing means and standard deviations; significance was set at p < 0.05. Clinical outcomes were measured with use of the Quality of Life-12 and Neck Disability Index.

RESULTS

Sixty-four patients were included in the analysis. There were 49 anterior cervical discectomies and fusions, 8 corpectomies, 1 hybrid procedure (corpectomy and adjacent discectomy), and 6 single-level arthroplasties. Patients who received corticosteroids had significantly better dysphagia scores on both the Bazaz scale and DSQ at most time points up to 6 months postoperatively (p < 0.05). On subgroup analysis, patients with multilevel (≥2-level) fusion benefited significantly from corticosteroids on both scales, whereas those with single-level procedures did not. There were no short-term wound complications or infections, and length of stay and fusion rates were comparable.

CONCLUSIONS

Perioperative administration of corticosteroids can reduce dysphagia symptoms following multilevel anterior cervical procedures. Benefit was noted immediately and up to 6 months postoperatively. There was no significant effect on short-term wound-healing, infection rates, length of stay, or fusion rates.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

A Comparison of Patient-Centered Outcome Measures to Evaluate Dysphagia and Dysphonia After Anterior Cervical Discectomy and Fusion

OF BACKGROUND DATA

Dysphagia and dysphonia are the most common complications after anterior cervical diskectomy and fusion (ACDF). No consensus system exists currently in the spine literature for the classification of these conditions postoperatively.

OBJECTIVE

The purpose of this analysis was to evaluate the validity and reliability of the Eating Assessment Tool (EAT-10) in the assessment of dysphagia when compared with the Bazaz score. A secondary goal was to assess the Voice Handicap Index (VHI-10) scores among patients following ACDF.

METHODS

Patients treated with ACDF (one, two, or three level) for cervical radiculopathy and/or cervical myelopathy at two tertiary hospitals were administered patient-reported outcome metrics preoperatively as well as at multiple time points postoperatively. The metrics administered included the EAT-10, VHI-10, Bazaz, Neck Disbability Index, and EuroQol Five Dimensions questionnaire (EQ-5D)/visual analog scale.

RESULTS

One hundred patients were included in this study. Eighty-nine percentage had a 1-year follow-up, and 100% had a 12-week follow-up. Mean Neck Disbability Index, EQ-5D, and EQ-visual analog scale scores all improved from baseline at both 6 months and 1 year postoperatively. Both the EAT-10 and VHI-10 demonstrated excellent internal reliability (α = 0.95 and α = 0.90, respectively). Analysis of variance of EAT-10 and VHI-10 scores by time point demonstrated a statistically significant relationship (P < 0.0001). The EAT-10 and VHI-10 scores were statistically greater on postoperative day 1 than at all other times (Tukey posthoc, P < 0.0001 and P < 0.004, respectively). Across all time points, 176 instances of clinically significant dysphagia (EAT-10 ≥ 3) were noted, 57 (32%) of which were classified as "None" on the Bazaz classification.

CONCLUSIONS

The EAT-10 score is an accurate measure for mild to severe dysphagia and better captured significant dysphagia that would have otherwise been missed when the Bazaz score is used. EAT-10 and VHI-10 are better measures of postoperative dysphagia and dysphonia than the current metrics used in spine surgery.

STUDY DESIGN

This was a prospective cohort study of consecutive patients.

Quantitative Risk Factor Analysis of Postoperative Dysphagia After Anterior Cervical Discectomy and Fusion (ACDF) Using the Eating Assessment Tool-10 (EAT-10)

STUDY DESIGN

A retrospective case series.

OBJECTIVE

The aim of this study was to utilize the Eating Assessment Tool-10 (EAT-10) to quantitatively analyze risk factors contributing to dysphagia after anterior cervical discectomy and fusion (ACDF).

SUMMARY OF BACKGROUND DATA

ACDF is one of the most common procedures performed in the United States, with postoperative dysphagia rates ranging from 2% to 60%. The EAT-10 is a self-administered, symptom-specific 10-item clinical instrument to document dysphagia symptom severity and has demonstrated excellent internal consistency, test-retest reliability, and criterion-based validity.

METHODS

This study utilized a retrospective chart review of 163 patients from July 2013 to October 2017 who underwent ACDF at a single institution and prospectively completed EAT-10 surveys pre- and postoperatively. EAT-10 scores were collected preoperatively and at postoperative day 1, day 14, 1 month, 3 months, 6 months, and 12 months. Preselected risk factors were abstracted from the patients' chart. Univariate analyses were performed to identify candidate variables that correlated with abnormal EAT-10 scores at each time point. Multivariate logistic regression was then utilized to identify risk factors that were independently correlated with abnormal EAT-10 scores at each time point.

RESULTS

Female gender, younger patients, and increased operating room (OR) time was associated with increased rates of dysphagia in the early postoperative period. History of obstructive sleep apnea, history of asthma, increased American Society of Anesthesiologists (ASA) score, and a larger number of spinal levels included in the surgery were correlated with increased dysphagia in the later postoperative periods.

CONCLUSION

Dysphagia is common following ACDF. Factors associated with longer-term dysphagia seem to be more associated with pre-existing medical comorbidities. Understanding risk factors that correlate with increased rates of dysphagia has the potential to improve preoperative patient counseling and changes in operative management.

LEVEL OF EVIDENCE

4.

Fixed Neck Position in Multilevel Cervical Posterior Decompression and Fusion to Reduce Postoperative Disturbances of Cervical Spine Function

Introduction

Difficulties with neck mobility often interfere with patients' activities of daily living (ADL) after cervical posterior spine surgery. The range of motion of the cervical spine decreases markedly after multilevel cervical posterior decompression and fusion (PDF). However, details regarding the limitations of cervical spine function due to postoperative reduced neck mobility after multilevel PDF are as yet unclarified. The present study aimed to clarify the quality of life and its related factors after PDF, and the optimal fixed neck position in multilevel PDF that minimizes the limitations of ADL accompanying markedly reduced postoperative neck mobility.

Methods

Limitations of ADL involving neck extension, rotation, and flexion were investigated in 32 consecutive patients who underwent C2-T1 PDF using the responses to the cervical spine function domain of the Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ). The EuroQol 5 Dimension, Japanese Orthopedic Association score, and five domains of the JOACMEQ were also investigated. We investigated the risk factors regarding the fixed neck position in PDF for the impossibility to perform ADL involving each of three movements using cut-off values obtained from receiver-operating characteristic curves.

Results

Postoperative comprehensive quality of life was significantly related to neurological improvements and to poor outcomes of cervical spine function after PDF. The significant risk factors for impossibility to perform ADL involving neck rotation were a C2-C7 lordotic angle ≥ 6° (P = 0.0057) or a proportion coefficient of C2-T1 tilt angle/C2-C7 lordotic angle ≤ 1.8 (P = 0.0024). There were no significant risk factors for impossibility to perform ADL involving neck extension or flexion.

Conclusions

The optimal fixed neck position in C2-T1 PDF to reduce postoperative limitations of ADL involving neck mobility is a C2-C7 lordotic angle of less than 6°, or a C2-T1 tilt angle (°) of greater than 1.8 × the C2-C7 lordotic angle (°).

The Effect of Local Versus Intravenous Corticosteroids on the Likelihood of Dysphagia and Dysphonia Following Anterior Cervical Discectomy and Fusion: A Single-Blinded, Prospective, Randomized Controlled Trial

BACKGROUND

Dysphagia and dysphonia are the most common postoperative complications following anterior cervical discectomy and fusion (ACDF). Although most postoperative dysphagia is mild and transient, severe dysphagia can have profound effects on overall patient health and on surgical outcomes. The purpose of this study was to compare the efficacy of local to intravenous (IV) steroid administration during ACDF on postoperative dysphagia and dysphonia.

METHODS

This was a single-blinded, prospective, randomized clinical trial. Seventy-five patients undergoing ACDF with cervical plating were randomized into 3 groups: control (no steroid), IV steroid (10 mg of IV dexamethasone at the time of closure), or local steroid (40 mg of local triamcinolone). Patient-reported outcome measures (PROMs) were collected for dysphagia, dysphonia, and neck pain postoperatively for 1 year.

RESULTS

Patient demographics were similar. Postoperative day 1 PROMs showed significantly lower scores for dysphonia (p = 0.015) and neck pain (p = 0.034) in the local steroid group. At 2 weeks postoperatively, the local steroid cohort showed significantly decreased prevalence of severe dysphagia (Eating Assessment Tool-10 [EAT-10], severe dysphagia, p = 0.027) compared with the control and IV steroid groups. Both steroid groups had significantly less severe dysphagia when compared with the control group at the 6-week and 3-month time points. At 1 year postoperatively, both steroid groups had significantly reduced dysphagia rates (p = 0.014) compared with the control group.

CONCLUSIONS

Both local and IV steroid administration after cervical plating in ACDF yielded better PROMs for dysphagia compared with a control group. This finding is particularly evident in the reduced number of patients who reported severe dysphagia symptoms following ACDF with local steroid application within the first 2 postoperative weeks. Future studies should attempt to stratify dysphagia severity when reporting outcomes related to anterior cervical spine surgery.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

The impact of the difference in O-C2 angle in the development of dysphagia after occipitocervical fusion: a simulation study in normal volunteers combined with a case-control study

BACKGROUND CONTEXT

Dysphagia has been recognized as one of the most serious complications after occipitocervical fusion (OCF), and the difference between postoperative and preoperative O-C2 angle (dO-C2A) was proposed to be an indicator in predicting and preventing dysphagia. Therefore, to prevent postoperative dysphagia, previous studies recommend that surgeons should correct the O-C2 angle (O-C2A) during surgery if the occipitocervical alignment was in an excessively flexed position. However, until now, there was no explicit indicator of the condition in which surgeons should adjust the patient's O-C2A during surgery.

PURPOSE

One of the purposes of this study was to explore the threshold of dO-C2A between dysphagia and normal swallowing by a simulation study. The other aim was to evaluate the validity of the threshold of dO-C2A in predicting dysphagia after OCF via a case-control study.

STUDY DESIGN

This is a simulation study combined with a retrospective case-control study.

PATIENT SAMPLE

Thirty volunteers were enrolled in the simulation study. Thirty-four consecutive patients who underwent OCF between September 2011 and September 2016 were included in the case-control study.

OUTCOME MEASURES

The outcome measures included O-C2A, C2-7 angle (C2-7A), atlantodental interval (ADI), the narrowest oropharyngeal airway space (nPAS), the rate of change in dnPAS (%dnPAS), and the prevalence of postoperative dysphagia.

MATERIALS AND METHODS

In the simulation study, each volunteer received two lateral x-rays of their cervical spine in neutral position and dysphagia position, respectively. We compared the radiographic parameters in neutral and dysphagia positions. The cumulative frequency diagram of dO-C2A in the dysphagia position was analyzed to identify the threshold of dO-C2A in the development of dysphagia. In the case-control study, these 34 patients were divided into two groups according to the threshold of dO-C2A identified in the simulation study. The impact of radiographic parameters on nPAS was analyzed. The prevalence of postoperative dysphagia between the two groups was compared to evaluate the validity of the threshold of dO-C2A in predicting dysphagia after OCF.

RESULTS

In the simulation study, the mean O-C2A and nPAS in the dysphagia position were significantly smaller than in the neutral position (p<.05). There was no significant difference between the mean C2-7A in the neutral and dysphagia positions (p>.05). There was a significant positive correlation between dO-C2A and dnPAS (p<.05). A dO-C2A of -5° delineated the threshold between normal swallowing and dysphagia. In the case-control study, multiple regression analysis showed that dO-C2A was the only significant variable correlated with dnPAS (β=0.769, p<.001). Among the reviewed 34 patients, the incidence of dysphagia was 17.6% (6/34) at 2 weeks after surgery and decreased over time to 11.8% (4 of 34) at the last follow-up. There was also a significant positive correlation between the dO-C2A and dnPAS (p<.05). The prevalence of dysphagia after OCF in patients with dO-C2A<-5° was as high as 66.7% (6/9). However, there was no patient suffering from dysphagia in patients with dO-C2A≥-5°.

CONCLUSION

The present study showed that the dO-C2A should be a key factor in the development of postoperative dysphagia after OCF. A dO-C2A of -5° could be the threshold between dysphagia and normal swallowing. Furthermore, to avoid dysphagia, surgeons should correct the O-C2A just before the final occipitocervical fixation if the checked dO-C2A during surgery is less than -5°.

HSS Dysphagia and Dysphonia Inventory (HSS-DDI) Following Anterior Cervical Fusion: Patient-Derived, Validated, Condition-Specific Patient-Reported Outcome Measure Outperforms Existing Indices

BACKGROUND

Dysphagia and dysphonia are common complications after anterior cervical spine surgery; however, reported prevalences vary greatly due to a lack of reliable clinical standards for measuring postoperative swallowing and speech dysfunction. The Hospital for Special Surgery Dysphagia and Dysphonia Inventory (HSS-DDI) was developed as a patient-derived, patient-reported instrument to measure dysphagia and dysphonia more accurately after anterior cervical spine surgery than existing indices.

METHODS

This multiphase survey-development study implemented a mixed-methods approach. Phase 1 involved qualitative assessment of postoperative patient-reported swallowing or speaking deficiencies to assemble a draft survey. Phase 2 established test-retest reliability and finalized the 31-item HSS-DDI. Phase 3 compared the HSS-DDI with the Swallowing-Quality of Life (SWAL-QOL) questionnaire and the M.D. Anderson Dysphagia Inventory (MDADI) for validity and responsiveness.

RESULTS

Phase 1, performed to formulate the draft survey, included 25 patients who were asked about speech and swallowing dysfunction after anterior cervical spine surgery involving at least 3 vertebral levels. Phase 2 included 49 patients who completed the draft survey twice. The mean scores (and standard deviation) for each administration of the HSS-DDI were 67 ± 24 and 75 ± 22, the Cronbach alpha coefficients were both 0.97, and the intraclass correlation coefficient was 0.80. The 31-item HSS-DDI was finalized with all but 2 items having weighted kappa values of ≥0.40. Phase 3 included 127 patients and established external validity, with most correlation coefficients between the HSS-DDI and the SWAL-QOL and MDADI ranging from 0.5 to 0.7. Internal validity was established by identifying worsening HSS-DDI scores with increases in the number of vertebral levels involved (p = 0.02) and in the Surgical Invasiveness Index (p = 0.006). HSS-DDI responsiveness ascertained by effect size (0.73) was better than that of the SWAL-QOL and MDADI. The average administration time for the HSS-DDI was 2 minutes and 25 seconds.

CONCLUSIONS

The HSS-DDI is efficient, valid, and more responsive to change after anterior cervical spine surgery than existing surveys.

CLINICAL RELEVANCE

The HSS-DDI fills a gap in postoperative assessment by providing a reliable, more clinically sensitive, patient and condition-specific evaluation of dysphagia and dysphonia prospectively and longitudinally.

Reoperation and complications after anterior cervical discectomy and fusion and cervical disc arthroplasty: a study of 52,395 cases

PURPOSE

The aim of this study was to analyze rates of perioperative complications and subsequent cervical surgeries in patients treated for cervical degenerative disc disease with anterior cervical discectomy and fusion (ACDF) and those treated with artificial cervical disc arthroplasty (ACDA) for up to 5-year follow-up.

METHODS

California's Office of Statewide Health Planning and Development discharge database was analyzed for patients aged 18-65 years undergoing single-level ACDF or ACDA between 2003 and 2010. Medical comorbidities were identified with CMS-Condition Categories. Readmissions for short-term complications of the procedure were identified and rates of subsequent cervical surgeries were calculated at 90-day and 1-, 3-, and 5-year follow-up. Multivariate regression modeling was used to identify associations with complications and subsequent cervical surgeries correcting for patient and provider characteristics.

RESULTS

A total of 52,395 eligible cases were identified: 50,926 ACDF and 1469 ACDA. Readmission was less common in the ACDA group (OR: 0.69, 95% CI: 0.48-1.0, p = 0.048). Subsequent cervical spine surgery was more common in the ACDF group in the immediate perioperative period (within 90 days of surgery) (ACDF 3.35% vs. ACDA 2.04%, OR: 0.63, 95% CI: 0.44-0.92, p = 0.015). At 1-, 3-, and 5-year postoperatively, rates of subsequent cervical surgeries were similar between the two cohorts.

CONCLUSIONS

We found no protective benefit for ACDA versus ACDF for single-level disease at up to 5-year follow-up in the largest cohort of patients examined to date. Early complications were rare in both cohorts stressing the value of large cohort studies to study risk factors for rare events. These slides can be retrieved under Electronic Supplementary Material.

Lower cervical levels: Increased risk of early dysphonia following anterior cervical spine surgery

OBJECTIVES

The present study aimed to re-evaluate the incidence of early dysphonia after anterior cervical spine surgery (ACSS) and to determine the related risk factors.

CLINICAL MATERIALS AND METHODS

Patients underwent ACSS between January 2011 and December 2013 at two sites were identified retrospectively from hospital's patient databases. A total of 233 cases were included in this study. Dysphonia developed 1 month postoperatively was recorded. Follow-up was conducted in all positive-response patients. Those reporting severe or persistent voice symptoms were referred to otolaryngologists for further assessments and (or) treatments. Pre and intraoperative factors were collected to determine their relationships with dysphonia one month postoperatively.

RESULTS

45 patients developed dysphonia at one month, including 23 males and 22 females, yielding to an incidence of 19.3%. 34 cases resolved themselves in 3 months, leaving the remaining 11 patients considered to be severe or persistent cases. However, 10 of them recovered spontaneously in the next 9 months, while the last case received vocal cord medialization and returned to almost normal speech function at 18 months. In univariate analysis, only approaching level involving C6-C7 or (and) C7-T1 was significantly associated with postoperative dysphonia (P<0.001). This association was not weakened in multiple logistic regression analysis (OR 2.348, 95% CI 1.467-3.659, P<0.001).

CONCLUSION

The incidence of early dysphonia following ACSS was relatively high and approaching at lower cervical levels was an independent predictive factor.