Vocal fold paralysis following the anterior approach to the cervical spine

Dysphagia as a predictor of voice handicap and voice restoration in unilateral vocal fold immobility

OBJECTIVE

Dysphagia is multifactorial in unilateral vocal fold immobility (UVFI). Severe dysphagia could indicate greater functional deficits in UVFI. The purpose of this study is to evaluate the association of dysphagia with the need for surgical voice restoration in patients with UVFI.

STUDY DESIGN

Retrospective chart review.

SETTING

Single-institution, tertiary referral center.

METHODS

Records of UVFI patients from 2008 to 2018 were examined. Dysphagia severity was extracted from patient history. Etiology of UVFI and other relevant variables were analyzed to determine their association with dysphagia. Dysphagia severity and other clinical variables were then analyzed for their association with surgical voice restoration.

RESULTS

Eighty patients met selection criteria out of 478 patients with UVFI. There was significant concordance between dysphagia severity extracted from patient history and patient-reported EAT-10 scores (R = 0.59, p = 0.000035). Patients' EAT-10 scores were correlated with VHI-10 scores (R = 0.45, p = 0.011). Severe dysphagia (p = 0.037), high VHI-10 score on presentation (p = 0.0009), and longer duration of hoarseness before presentation (p = 0.008) were associated with surgical voice restoration in UVFI patients.

CONCLUSION

In this pilot study, severe dysphagia and increased voice handicap on presentation were associated with the need for surgical voice restoration in UVFI patients. Presenting dysphagia may be an additional variable for clinicians to consider for management of UVFI.

Early Voice and Swallowing Disturbance Incidence and Risk Factors After Revision Anterior Cervical Discectomy and Fusion Using a Multidisciplinary Surgical Approach: A Retrospective Cohort Evaluation of a Prospective Database

BACKGROUND AND OBJECTIVES

Dysphagia and vocal cord palsy (VCP) are common otolaryngological complications after revision anterior cervical discectomy and fusion (rACDF) procedures. Our objective was to determine the early incidence and risk factors of VCP and dysphagia after rACDF using a 2-team approach.

METHODS

Single-institution, retrospective analysis of a prospectively collected database of patients undergoing rACDF was enrolled from September 2010 to July 2021. Of 222 patients enrolled, 109 patients were included in the final analysis. All patients had prior ACDF surgery with planned revision using a single otolaryngologist and single neurosurgeon. MD Anderson Dysphagia Inventory and fiberoptic endoscopic evaluation of swallowing (FEES) were used to assess dysphagia. VCP was assessed using videolaryngostroboscopy.

RESULTS

Seven patients (6.7%) developed new postoperative VCP after rACDF. Most cases of VCP resolved by 3 months postoperatively (mean time-to-resolution 79 ± 17.6 days). One patient maintained a permanent deficit. Forty-one patients (37.6%) reached minimum clinically important difference (MCID) in their MD Anderson Dysphagia Inventory composite scores at the 2-week follow-up (MCID decline of ≥6), indicating new clinically relevant swallowing disturbance. Forty-nine patients (45.0%) had functional FEES Performance Score decline. On univariate analysis, there was an association between new VCPs and the number of cervical levels treated at revision ( P = .020) with long-segment rACDF (≥4 levels) being an independent risk factor ( P = .010). On linear regression, there was an association between the number of levels treated previously and at revision for FEES Performance Score decline ( P = .045 and P = .002, respectively). However, on univariate analysis, sex, age, body mass index, operative time, alcohol use, smoking, and individual levels revised were not risk factors for reaching FEES Performance Score decline nor MCID at 2 weeks postoperatively.

CONCLUSION

VCP is more likely to occur in long-segment rACDF but is often temporary. Clinically relevant and functional rates of dysphagia approach 37% and 45%, respectively, at 2 weeks postoperatively after rACDF.

Changes in vocal fold gene expression and histology after injection augmentation in a recurrent laryngeal nerve injury model

OBJECTIVE

To investigate changes in neuroregenerative pathways with vocal fold denervation in response to vocal fold augmentation.

METHODS

Eighteen Yorkshire crossbreed swine underwent left recurrent laryngeal nerve transection, followed by observation or augmentation with carboxymethylcellulose or calcium hydroxyapatite at two weeks. Polymerase chain reaction expression of genes regulating muscle growth (MyoD1, MyoG and FoxO1) and atrophy (FBXO32) were analysed at 4 and 12 weeks post-injection. Thyroarytenoid neuromuscular junction density was quantified using immunohistochemistry.

RESULTS

Denervated vocal folds demonstrated reduced expression of MyoD1, MyoG, FoxO1 and FBXO32, but overexpression after augmentation. Healthy vocal folds showed increased early and late MyoD1, MyoG, FoxO1 and FBXO32 expression in all animals. Neuromuscular junction density had a slower decline in augmented compared to untreated denervated vocal folds, and was significantly reduced in healthy vocal folds contralateral to augmentation.

CONCLUSION

Injection augmentation may slow neuromuscular degeneration pathways in denervated vocal folds and reduce compensatory remodelling in contralateral healthy vocal folds.

Multilevel anterior cervical fusion with standalone cage or cage-and-plate after cervical discectomy: Benefits and drawbacks

PURPOSE

Multilevel anterior cervical discectomy and fusion (ACDF), especially two-level ACDF, has been usually performed in the cervical degenerative disease, and the incidence rate of complications is controversial. This study aimed to compare the outcomes of ACDF approach with cage alone and with plate fixation in multilevel discectomy.

METHODS

Patients who had undergone multilevel ACDF by the Smith-Robinson methods were included from 2018 to 2020. Data were collected using a questionnaire containing demographic characteristics, surgical complications, and outcome. All the patients were followed for 18 months post-surgery. Visual Analogue Scale (VAS), Neck Disability Index (NDI) and Nurick Grading scale were used to measure the pain degree, neck pain effect, and myelopathy grade, respectively. Bone fusion rate, subsidence and instrument failure were checked through radiography. Data were analyzed using SPSS, and the significant level was considered 0.05.

RESULTS

24 patients were included. There was no significant difference between the mean blood losses in the two groups. The rate of subsidence was much higher in group B after 18 months (60% vs 14.3%). As to the VAS score, NDI, and Nurick scale, trend change overtime was significantly improved in each group, but there was no significant difference between the groups. There was no significant difference between the two groups regarding bony fusion rate.

DISCUSSION

ACDF with plate leads to a more prolonged surgery with no significant benefits. Stand-alone cage approach could be suggested as the gold standard for anterior cervical discectomy.

Intraoperative Measurement of Endotracheal Tube Cuff Pressure and Its Change During Surgery in Correlation With Recurrent Laryngeal Nerve Palsies, Hoarseness, and Dysphagia After Anterior Cervical Discectomy and Fusion: A Prospective Randomized Controlled Trial

STUDY DESIGN

Prospective randomized controlled trial.

OBJECTIVES

Adjustment of endotracheal tube cuff pressure (ETCP) in anterior cervical discectomy and fusion (ACDF) may influence the incidence of complications such as recurrent laryngeal nerve palsy (RLNP), hoarseness, and dysphagia.

METHODS

The prospective randomized controlled trial was designed to investigate the influence of ETCP on the incidence of postoperative complications. All eligible patients underwent vocal cord examination before and after ACDF and were randomized into a control group (CG) and intervention group (IG). Endotracheal tube cuff pressure was passively monitored in CG, and in IG, it was maintained at 20 mmHg. Outcomes were evaluated during hospitalization and during follow-up.

RESULTS

A total of 98 patients were randomized, each group consisted of 49 patients. Statistical analysis showed that gender and age did not influence the incidence of complications. In CG, duration of retractor placement and extent of approach significantly impacted the occurrence of complications. The incidence of postoperative RLNP was 8.2% in IG and 12.2% in CG, hoarseness and dysphonia were present in 18.4% in IG and in 37.5% in CG, and dysphagia in 20.8% in IG and in 22.5% in CG. Hoarseness was significantly present more in CG (P = .018). Only one patient from CG presented with RLNP after 1 year, the remaining nine patients spontaneously recovered.

CONCLUSIONS

Unregulated ETCP can lead to a significantly higher incidence of hoarseness; however, its improvement rate is 100%. The early postoperative complication rate was higher in CG, and after one year, 1 patient had RLNP and 1 patient had dysphagia.

Delayed-Onset Bilateral Vocal Fold Paralysis Following Anterior Cervical Discectomy and Fusion Surgery

A 68-year-old man with heart disease and obesity who had undergone surgery for cervical spondylotic myelopathy presented with difficulty breathing. What is your diagnosis?

Augmentation and vocal fold biomechanics in a recurrent laryngeal nerve injury model

Objectives/hypothesis

Composite vocal fold (VF) biomechanical data are lacking for augmentation after recurrent laryngeal nerve (RLN) injury. We hypothesize resulting atrophy decreases VF stiffness and augmentation restores native VF biomechanics.

Methods

Sixteen Yorkshire Crossbreed swine underwent left RLN transection and were observed or underwent carboxymethylcellulose (CMC) or calcium hydroxyapatite (CaHa) augmentation at 2 weeks. Biomechanical measurements (structural stiffness, displacement, and maximum load) were measured at 4 or 12 weeks. Thyroarytenoid (TA) muscle cross‐sectional area was quantified and compared with two‐way ANOVA with Tukey's post hoc test.

Results

After 4 weeks, right greater than left structural stiffness (mean ± SE) was observed (49.6 ± 0.003 vs. 28.4 ± 0.002 mN/mm), left greater than right displacement at 6.3 mN (0.54 ± 0.01 vs. 0.46 ± 0.01 mm, p < .01) was identified, and right greater than left maximum load (72.3 ± 0.005 vs. 40.8 ± 0.003 mN) was recorded. TA muscle atrophy in the injured group without augmentations was significant compared to the noninjured side, and muscle atrophy was seen at overall muscle area and individual muscle bundles. CMC augmentation appears to maintain TA muscle structure in the first 4 weeks with atrophy present at 12 weeks.

Conclusions

VF biomechanical properties match TA muscle atrophy in this model, and both CMC and CaHa injection demonstrated improved biomechanical properties and slower TA atrophy compared to the uninjured side. Taken together, these data provide a quantifiable biomechanical basis for early injection laryngoplasty to improve dysphonia and potentially improve healing in reversible unilateral vocal fold atrophy.

Level of evidence

N/A

Laryngoscopic Screening Before Revision Anterior Cervical Spine Surgery: Is Vocal Cord Palsy a Relevant Factor in Deciding the Approach Direction?

STUDY DESIGN

Retrospective study.

OBJECTIVES

The aim was to evaluate the exact incidence of vocal cord palsy (VCP) caused by previous anterior cervical spine surgery (ACSS) and aid surgeons in deciding the approach direction in revision ACSS.

SUMMARY OF BACKGROUND DATA

The incidence of VCP detected by preoperative laryngoscopic screening before revision ACSS appeared to be much higher in previous reports than in our experience.

MATERIALS AND METHODS

We reviewed the data of 64 patients who underwent revision ACSS. Preoperative laryngoscopy was performed in all patients to detect VCP and/or structural abnormalities of the vocal cords. The patients' characteristics, laryngoscopy results, and symptoms before revision surgery that were potentially caused by previous recurrent laryngeal nerve injuries (voice change, foreign body sensation, and chronic aspiration) were recorded.

RESULTS

Laryngoscopy demonstrated no complete VCP or decreased vocal cord motility. Eleven patients (17.2%) showed vocal cord-related symptoms and 13 patients (20.3%) showed abnormal laryngoscopic findings without VCP. Four patients (6.2%) showed vocal cord-related symptoms and abnormal laryngoscopic findings simultaneously. At the initial operative level, no significant differences in vocal cord-related symptoms were observed between the upper and lower levels (C3-4-5 vs. C5-6-7). However, the frequency of vocal cord-related symptoms was significantly high at the larger number of levels (≥3 segments) (P=0.010).

CONCLUSIONS

In contrast to previous reports, this study demonstrated that VCP is rarely detected before revision ACSS. Therefore, deciding the approach direction with only vocal cord motility can be dangerous, and more attention is required in setting the approach direction in patients who show both vocal cord-related symptoms and abnormal laryngoscopic finding. In other cases, a contralateral approach which has a low risk of bilateral VCP could be utilized if necessary.

DEGENERATIVE CERVICAL MYELOPATHY: A REVIEW OF CURRENT CONCEPTS

ABSTRACT Herbert von Luschka, a German anatomist, was the first to describe the developmental changes in the anatomical structures of the cervical spine. Degenerative cervical myelopathy (DCM) represents a collection of pathological entities that cause compression of the cervical spinal cord, resulting in a clinical syndrome typified by spasticity, hyperreflexia, pathologic reflexes, finger/hand clumsiness, gait disturbance and sphincter dysfunction. In the cervical spine, certain patients are more likely to have myelopathy due to a congenitally narrowed cervical spine canal. Degenerative changes are more common at C5 and C6 or C6 and C7 due to the increased motion at these levels. Additional contributors to canal narrowing are infolding of the ligamentum flavum, olisthesis, osteophytes, and facet hypertrophy. Myelopathy will develop in approximately 100% of patients with canal stenosis greater than 60% (less than 6 mm sagittal disc cord space). Classically it has an insidious onset, progressing in a stepwise manner with functional decline. Without treatment, patients may progress toward significant paralysis and loss of function. Treatment requires surgery with either anterior or posterior decompression of the area of narrowing, and probable fusion. Factors of a poor prognosis include symptoms lasting for more than 18 months, increased range of motion in the cervical spine, and female gender. In this study, we give an overview of the state-of-the-art in DCM, with a focus on the pathophysiology, clinical presentation, differential diagnosis, imaging evaluation, natural history, treatment options and complications. Level of evidence III; Review article.

Recurrent laryngeal nerve injury following single- and multiple-level anterior cervical discectomy and fusion: a meta-analysis

Background

Recurrent laryngeal nerve (RLN) palsy is a common and potentially debilitating complication of anterior cervical discectomy and fusion (ACDF). The relationship between the risk of RLN palsy and the number of operated levels remains unclear, and no previous studies address potential differences between short- and long-term RLN injury following ACDF.

Methods

Electronic searches of PubMed, Cochrane, ScienceDirect and Google Scholar were performed from database inception to June 2019. Relevant studies reporting the rate of RLN palsy for patients undergoing ACDF for cervical spine pathology were identified according to predetermined inclusion and exclusion criteria. Statistical analysis was performed using fixed effects and random effects modelling. I2 and Q statistics were used to explore heterogeneity.

Results

Five studies with a total of 3,514 patients were included in the meta-analysis. The incidence of RLN palsy was found to be 1.2%. There were no statistically significant differences in the rate of RLN palsy between multiple- and single-level ACDF [odds ratio (OR) 1.04; 95% CI: 0.56-1.95; P=0.891, I2=0%]. There were similarly no statistically significant differences in RLN palsy rates for multiple- and single-level ACDF when patients were stratified based on length of follow-up of less than or greater than 12 months.

Conclusions

This analysis suggests that there is no statistically significant association between the number of ACDF operative levels and the risk of short- or long-term RLN palsy.

Ultrasound prediction for vocal cord dysfunction in patients scheduled for anterior cervical spine surgeries: a prospective cohort study

Prediction of vocal cord dysfunction is essential after anterior cervical spine surgeries. This study aimed to detect the validity of transcutaneous laryngeal ultrasonography by both anterior and novel lateral approaches for prediction of vocal cord edema and paralysis after anterior cervical spine surgeries. A prospective cohort study conducted on 90 patients scheduled for anterior cervical spine surgeries underwent consecutive pre and postoperative vocal cord examination for edema and paralysis by both anterior and lateral approaches laryngeal ultrasonography. Rigid laryngoscopy was the standard confirmatory tool. For postoperative vocal cord edema, the anterior ultrasonography approach diagnostic sensitivity = 88.2%, specificity = 78.9% with PPV = 78.9% and NPV = 88.2% and the novel lateral ultrasonography approach diagnostic sensitivity = 88.2%, specificity = 94.7% with PPV = 93.75% and NPP = 90%. While for paralysis, the anterior ultrasonography approach diagnostic sensitivity = 86.7%, specificity = 85.7% with PPV = 81.25% and NPV = 90% and the novel lateral ultrasonography approach diagnostic (sensitivity, specificity with PPV and NPP) = 100%. The diagnostic accuracy of the novel lateral approach was more correlated to rigid laryngoscopy (91.7% and 100%) compared to anterior approach for vocal cord edema and paralysis (83.3% and 80.6%). Overall incidence of vocal cord paralysis was 16.6%. Risk of vocal cord paralysis was statistically significant more in female, multiple disc herniation, lower and mixed disc levels, Langenbeck retractor, cage and plate and duration of surgery ≥ 1.5 h. Transcutaneous Laryngeal ultrasound is a valid comfortable tool for prediction of vocal cord edema and paralysis after anterior cervical spine surgeries with superiority of the novel lateral over anterior approach.

Complications of anterior cervical spine surgery: a systematic review of the literature

The anterior approach to the cervical spine is commonly utilized for a variety of degenerative, traumatic, neoplastic, and infectious indications. While many potential complications overlap with those of the posterior approach, the distinct anatomy of the anterior neck also presents a unique set of hazards. We performed a systematic review of the literature to assess the etiology, presentation, natural history, and management of these complications. Following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), a PubMed search was conducted to evaluate clinical studies and case reports of patients who suffered a complication of anterior cervical spine surgery. The search specifically included articles concerning adult human subjects, written in the English language, and published from 1989 to 2019. The PubMed search yielded 240 articles meeting our criteria. The overall rates of complications were as follows: dysphagia 5.3%, esophageal perforation 0.2%, recurrent laryngeal nerve palsy 1.3%, infection 1.2%, adjacent segment disease 8.1%, pseudarthrosis 2.0%, graft or hardware failure 2.1%, cerebrospinal fluid leak 0.5%, hematoma 1.0%, Horner syndrome 0.4%, C5 palsy 3.0%, vertebral artery injury 0.4%, and new or worsening neurological deficit 0.5%. Morbidity rates in anterior cervical spine surgery are low. Nevertheless, the unique anatomy of the anterior neck presents a wide variety of potential complications involving vascular, aerodigestive, neural, and osseous structures.

Right Versus Left Approach to Anterior Cervical Discectomy and Fusion: An Anatomic Versus Historic Debate

The debate over the influence approach sidedness has on the risk of recurrent laryngeal nerve palsy (RLNP) following anterior cervical discectomy and fusion (ACDF) has its origins with the introduction of the procedure for radicular pain in the 1950s. The recurrent laryngeal nerves follow disparate courses in the lower neck secondary to differences in embryogenesis. Because of these differences, some authors believe a right-sided approach increases the risk of RLNP. However, modern surgical series have not shown a clear risk of RLNP with a right- versus left-sided approach. By looking at the historical context surrounding the introduction of ACDF, we propose the dogmatic view of an increased risk of RLNP with a right-sided approach likely arose from a combination of theoretical anatomic risk and the early surgical experience of a pioneer of the procedure.

Esophageal Perforation due to Anterior Cervical Spine Hardware Placement: Case Series

Context. This case series discusses surgical management of esophageal perforations that occurred following cervical spine hardware placement. Purpose. (1) Determine presenting symptoms of esophageal perforation after anterior cervical spine hardware placement. (2) Discuss surgical management of these resulting esophageal perforation complications. Design/Setting. Case series of six patients at a tertiary-care, academic medical center. Patient Sample. Six patients with pharyngoesophageal perforations following anterior cervical spine surgery (ACSS). Outcome Measures. Date of ACSS, indication for ACSS, level of hardware, location of esophageal or pharyngeal injury, symptoms at presentation, surgical intervention, type of reconstruction flap, wound culture flora, and antibiotic choice. Methods. A retrospective review of patients with an esophageal or hypopharyngeal injury in the setting of prior ACSS managed by the otolaryngology service at a tertiary, academic center between January 2015 and January 2019. Results. Six patients who experienced pharyngoesophageal perforation following ACSS are included in this study. Range of presentation was two weeks to eight years following initial hardware placement. Five patients presented with an abscess and all had evidence of perforation on initial CT or esophagram. All patients underwent repair with a sternocleidomastoid flap with two patients eventually requiring an additional pectoralis myofascial flap for a persistent esophageal leak. Five patients eventually attained ability to tolerate oral nutrition. An algorithm detailing surgical reconstructive management is proposed. Conclusions. Esophageal perforations in the setting of prior ACSS are challenging clinical problems faced by otolaryngologists. Consideration should be given to early drainage of abscesses and spine surgery evaluation. Spinal hardware removal is recommended whenever possible. Utilization of a pedicled muscle flap reinforces primary closure and allows coverage of the vertebral bony defect. Nutrition, thyroid repletion, and culture-directed IV antibiotics are necessary to optimize esophageal perforation repair.

Laser Partial Arytenoidectomy as an Office Procedure

Bilateral vocal fold paralysis is a disabling condition that results in airway symptoms, dysphonia, and sometimes difficulty swallowing. Various types of glottal widening procedures have been described in the literature, all of which are performed in the operating room under general anesthesia. The aim is to report laser partial arytenoidectomy as an office-based treatment modality in a patient with bilateral vocal fold paralysis. Using Thulium laser fiber introduced through the working channel of fiberoptic nasopharyngoscope, a posterior cordectomy followed by resection of the vocal process of the right arytenoid was performed. The laser was used in a pulsed mode, power range 3.5 to 4.5 W, duration 70 to 300 milliseconds, repetition 2 to 4 Hz, and aiming beam 65%. The procedure was well tolerated and the patient was successfully decannulated 3 weeks later. Unsedated office-based laser arytenoidectomy might be considered a safe alternative to the commonly practiced glottal widening procedures in patients with a preexisting tracheotomy.

Modified high cervical approach for C3-4 anterior pathology in difficult neck patients

Introduction:

The anterior approach to cervical pathologies is a time-tested versatile approach. It is, however, associated with a number of pharyngo-tracheo-laryngeal complications (PTL complications) such as dysphonia, dysphagia, and aspiration, more commonly in high cervical C3-4 inclusive pathologies and even more so in patients with “difficult neck.” The modified high cervical approach was devised and employed to address these issues at our institution.

Materials and Methods:

Patients who underwent surgery for anterior cervical C3-4 inclusive pathologies between January 2015 and April 2018 were included in the study. Parameters for considering difficult neck were defined. Patient subgroup with difficult neck underwent surgery through a modified high cervical approach, whereas others underwent surgery through a standard approach. The incidence of pharyngo-tracheo-laryngeal complications in both subgroups of this patient set was compared among itself as well with a similar patient set with the same two subgroups, both of which underwent surgery through standard approach alone from May 2010 to December 2014 – before the introduction of modified high cervical approach.

Results:

A total of 280 patients underwent surgery for C3-4 level pathology between May 2010 and April 2018. There were 197 males and 93 females in this population. Mean age was 45.8 ± 6.3 years. Incidence of pharyngo-tracheo-laryngeal complications was 20.3% in patients who underwent surgery before the employment of modified high cervical approach – 32.4% of difficult neck and 16.6% of others developed features of pharyngo-tracheo-laryngeal complications. After employment of modified high cervical approach, 16.67% of difficult neck and 16.2% of other patients developed features of pharyngo-tracheo-laryngeal complications.

Conclusion:

The modified high cervical technique is a good surgical option to prevent pharyngo-tracheo-laryngeal complications in cases of anterior C3-4 pathology when operating of patients with difficult neck.

Risk factors and preventative measures of early and persistent dysphagia after anterior cervical spine surgery: a systematic review

PURPOSE

To conduct a systematic review of literature to determine risk factors and preventative measures of early and persistent dysphagia after anterior cervical spine surgery (ACSS).

METHODS

On March 2017, we searched the database PubMed, Medline, EMBASE, the Cochrane library, Clinical key, Springer link and Wiley Online Library without time restriction using the term 'dysphagia', 'swallowing disorders', and 'anterior cervical spine surgery'. Selected papers were examined for the level of evidence by published guidelines as level I, level II, level III, level IV studies. We investigated risk factors and preventative measures of early or persistent dysphagia after ACSS from these papers.

RESULTS

The initial search yielded 515 citations. Fifty-nine of these studies met the inclusion and exclusion criteria. Three of them were level I evidence studies, 29 were level II evidence studies, 22 were level III evidence studies, and 3 were level IV evidence studies. Preventable risk factors included prolonged operative time, use of rhBMP, endotracheal tube cuff pressure, cervical plate type and position, dC2-C7 angle, psychiatric factors, tobacco usage, prevertebral soft tissue swelling, SLN or RLN palsy or injury of branches. Preventative measures included preoperative tracheal traction exercise, maintaining endotracheal tube cuff pressure at 20 mm Hg, avoiding routine use of rhBMP-2, use of zero-profile implant, use of Zephir plate, use of new cervical retractor, steroid application, avoiding prolonged operating time, avoiding overenlargement of cervical lordosis, decreasing surgical levels, ensuring knowledge of anatomy of superior laryngeal nerve and recurrent laryngeal nerve, to comfort always, patients quitting smoking and doctors ensuring improved skills. Unpreventable risk factors included age, gender, multilevel surgery, revision surgery, duration of preexisting pain, BMI, blood loss, upper levels, preoperative comorbidities and surgical type.

CONCLUSION

Adequate preoperative preparation of the patients including preoperative tracheal traction exercise and quitting smoking, proper preventative measures during surgery including maintaining endotracheal tube cuff pressure at 20 mm Hg, avoiding routine use of rhBMP-2, use of zero-profile implant, use of Zephir plate, use of new cervical retractor, steroid application, avoiding prolonged operating time, avoiding overenlargement of cervical lordosis and decreasing surgical levels, doctors ensuring knowledge of anatomy, improved surgical techniques and to comfort always are essential for preventing early and persistent dysphagia after ACSS.

Anterior cervical spine surgery-associated complications in a retrospective case-control study

Anterior cervical spine procedures have been associated with satisfactory outcomes. However, the occurrence of troublesome complications, although uncommon, needs to be taken into consideration. The purpose of our study was to assess the actual incidence of anterior cervical spine procedure-associated complications and identify any predisposing factors. A total of 114 patients undergoing anterior cervical procedures over a 6-year period were included in our retrospective, case-control study. The diagnosis was cervical radiculopathy, and/or myelopathy due to degenerative disc disease, cervical spondylosis, or traumatic cervical spine injury. All our participants underwent surgical treatment, and complications were recorded. The most commonly performed procedure (79%) was anterior cervical discectomy and fusion (ACDF). Fourteen patients (12.3%) underwent anterior cervical corpectomy and interbody fusion, seven (6.1%) ACDF with plating, two (1.7%) odontoid screw fixation, and one anterior removal of osteophytes for severe Forestier's disease. Mean follow-up time was 42.5 months (range, 6-78 months). The overall complication rate was 13.2%. Specifically, we encountered adjacent intervertebral disc degeneration in 2.7% of our cases, dysphagia in 1.7%, postoperative soft tissue swelling and hematoma in 1.7%, and dural penetration in 1.7%. Additionally, esophageal perforation was observed in 0.9%, aggravation of preexisting myelopathy in 0.9%, symptomatic recurrent laryngeal nerve palsy in 0.9%, mechanical failure in 0.9%, and superficial wound infection in 0.9%. In the vast majority anterior cervical spine surgery-associated complications are minor, requiring no further intervention. Awareness, early recognition, and appropriate management, are of paramount importance for improving the patients' overall functional outcome.

Effect of perioperative steroids on dysphagia after anterior cervical spine surgery: A systematic review

BACKGROUND

Dysphagia following anterior cervical spine surgery is common. Steroids potentially reduce post-operative inflammation that leads to dysphagia; however, the efficacy, optimal dose and route of steroid administration have not been fully elucidated.

OBJECTIVE

The purpose of this systematic review is to evaluate the effect of peri-operative steroids on the incidence and severity of dysphagia following anterior cervical spine surgery.

METHODS

A PubMed search adherent to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed to include clinical studies reporting use of steroids in adult patients following anterior cervical spine surgery. Data regarding steroid dose, route and timing of administration were abstracted. Incidence and severity of post-operative dysphagia were pooled across studies.

RESULTS

Seven of 72 screened articles met inclusion criteria for a total of 246,298 patients that received steroids. Patients that received systemic and local steroids had significant reductions in rate and severity of dysphagia postoperatively. Reduction of dysphagia severity was more pronounced in patients undergoing multilevel procedures in both groups. There was no difference in infectious complications among patients that received steroids compared with controls. There was no difference in fusion rates at long-term follow-up.

CONCLUSIONS AND CLINICAL RELEVANCE

Steroids may reduce dysphagia after anterior cervical spinal procedures in the early post-operative period without increasing complications. This may be especially beneficial in patients undergoing multilevel procedures. Future studies should further define the optimal dose and route of steroid administration, and the specific contraindications for use.

Do the complications increased in the anterolateral right-side approach to treat the cervical degenerative disorders? A retrospective cohort study

The dysphagia and recurrent laryngeal nerve (RLN) palsy are the most common complications of the patients who underwent anterior cervical surgery in the current literature. These morbidities have led to the study of the impact of sidedness in anterior cervical spine surgery. However, many reports documented the left-side was more effective and safe than right-side based on the anatomy. So the right-side approach is more challenging. We retrospectively study 503 patients with cervical degenerative diseases who underwent cervical spinal surgery using anterolateral right-side approach in our spine center from September 1999 to December 2012 and evaluate the efficient and safety of the anterolateral right-side approach to treat the cervical degenerative diseases. The overall mortality rate in our present report was 3.38% (17 of 503 patients). The most common complication which observed in 2.80% of our cases was dysphagia. Postoperatively, there was only one patient with hematoma and died (0.19%) and symptomatic recurrent laryngeal nerve palsy occurred in 0.39% of the cases. The anterolateral right-side anterior approach didn't increase the incidence of the dysphagia and recurrent laryngeal nerve (RLN) palsy.

Indications for Direct Laryngoscopic Examination of Vocal Cord Function Prior to Anterior Cervical Surgery

Recurrent laryngeal nerve palsy (RLNP) is among the most common complications in both thyroid surgeries and anterior approaches to the cervical spine, having both a diverse etiology and presentation. Most bilateral paresis, with subsequent devastating impact on patients, are due to failure to recognize unilateral recurrent laryngeal nerve paralysis and, although rare, are entirely preventable with appropriate history and screening. Recurrent laryngeal nerve palsy has been shown to present asymptomatically in as high as 32% of cases, which yields limitations on exclusively screening with physical examination. Based on the available literature, diagnosis of unilateral RLNP is the critical factor in preventing the occurrence of bilateral RLNP as the surgeon may elect to operate on the injured side to prevent bilateral paresis. Analysis of incidence rates shows postoperative development of unilateral RLNP is 13.1 (95% confidence interval [CI]: 6.1-28.1) and 13.90 (95% CI: 6.6-29.3) times more likely in anterior spine and thyroid surgery, respectively, in comparison with intubation. Currently, there is no consensus on when to order a preoperative laryngoscopic examination prior to anterior cervical spine surgery. The importance of patient history should be emphasized, as it is the basis for indications of preoperative laryngoscopy. Efforts to minimize postoperative complications must be made, especially when considering the rising rate of cervical fusion. This study presents a systematic review of the literature defining key causes of RLNP, with a probability-based protocol to indicate direct laryngoscopy prior to anterior cervical surgery as a screening tool in the prevention of bilateral RLNP.

A Clinical Comparison of Anterior Cervical Plates Versus Stand-Alone Intervertebral Fusion Devices for Single-Level Anterior Cervical Discectomy and Fusion Procedures

OBJECTIVE

To compare radiologic and clinical outcomes, including rates of dysphagia and dysphonia, using a no-profile stand-alone intervertebral spacer with integrated screw fixation versus an anterior cervical plate and spacer construct for single-level anterior cervical discectomy and fusion (ACDF) procedures.

METHODS

This multicenter, randomized, prospective study included 54 patients with degenerative disc disease requiring ACDF at a single level at C3-C7. Twenty-six patients underwent single-level ACDF with stand-alone spacers, and 28 with plate fixation and spacers. Analyses were based on comparison of perioperative outcomes, radiologic and clinical metrics, and incidence of dysphagia and/or dysphonia.

RESULTS

Mean patient age was 48.8 ± 10.1years (53.7% female). No significant differences were observed between groups in operative time (101.8 ± 34.4 minutes, 114.4 ± 31.5 minutes), estimated blood loss (44.8 ± 76.5 mL, 82.5 ± 195.1 mL), or length of hospital stay (1.2 ± 0.6 days, 1.3 ± 0.6 days). Mean visual analog scale pain scores and Neck Disability Index scores improved significantly from preoperative to last follow-up (10.8 ± 2.6 months) in both groups (P < 0.05). Mean Voice Handicap Index and Eating Assessment Tool scores improved significantly from discharge to last follow-up in both groups (P < 0.05). From discharge to 6 months, the stand-alone spacers group consistently demonstrated greater improvement in Voice Handicap Index. Preoperative intervertebral disc and neuroforaminal heights increased significantly across treatment groups (P < 0.01), and no cases required surgical revision at index or adjacent levels.

CONCLUSIONS

Anterior cervical discectomy and fusion with stand-alone spacers resulted in similar clinical and radiologic outcomes as compared with plate and spacers and may help minimize postoperative dysphonia.

Intraoperative Neurophysiological Monitoring of the Laryngeal Nerves During Anterior Neck Surgery: A Review

Contributions to the literature on intraoperative neuro monitoring (IONM) during endocrine and head and neck surgery have increased over recent years. Organizational support for neural monitoring during surgery is becoming evident and is increasingly recognized as an adjunct to visual nerve identification. A comprehensive understanding of the role of IONM for prevention of nerve injuries is critical to maximize safety during surgery of the anterior compartment of the neck. This review will explore the potential advantages of IONM to improve the outcomes among patients undergoing anterior neck surgery.

Dysphagia and Dysphonia Assessment Tools After Anterior Cervical Spine Surgery

The Smith-Robinson approach to the anterior cervical spine is being increasingly used, but it is not without complication. Dysphagia and dysphonia are the most common complications of the procedure. Many classification systems have been developed to stage and grade postoperative dysphagia and dysphonia, but inconsistent usage and lack of consensus adoption has limited research progress. A discussion of the merits and limitations of the most common classification systems is outlined within this review. Broad adoption of comprehensive and simple classification metrics is needed, but, first, prospective reliability and validity must be established in the anterior cervical fusion population.

Unilateral True Vocal Fold Paralysis: Cause of Right-Sided Lesions

At the Georgetown University Center for the Voice, 778 patients were referred for evaluation between July 1, 1990, and June 30, 1995. During this 5-year period, right true vocal fold paralysis or paresis was diagnosed in 24 of these patients (3%). Videostroboscopy, voice analysis, and patient records were reviewed. Ages ranged from 23 to 80 years, and sex distribution approximated a 1:1 ratio. The patients presenting symptoms included hoarseness, dysphagia, choking, voice pitch change, voice weakness, fatigability, and breathiness. Sources of the vocal fold dysfunction included iatrogenic, traumatic, central, and infectious causes.

Consensus statement: Using laryngeal electromyography for the diagnosis and treatment of vocal cord paralysis

INTRODUCTION

The purpose of this study was to develop an evidence-based consensus statement regarding use of laryngeal electromyography (LEMG) for diagnosis and treatment of vocal fold paralysis after recurrent laryngeal neuropathy (RLN).

METHODS

Two questions regarding LEMG were analyzed: (1) Does LEMG predict recovery in patients with acute unilateral or bilateral vocal fold paralysis? (2) Do LEMG findings change clinical management in these individuals? A systematic review was performed using American Academy of Neurology criteria for rating of diagnostic accuracy.

RESULTS

Active voluntary motor unit potential recruitment and presence of polyphasic motor unit potentials within the first 6 months after lesion onset predicted recovery. Positive sharp waves and/or fibrillation potentials did not predict outcome. The presence of electrical synkinesis may decrease the likelihood of recovery, based on 1 published study. LEMG altered clinical management by changing the initial diagnosis from RLN in 48% of cases. Cricoarytenoid fixation and superior laryngeal neuropathy were the most common other diagnoses observed.

CONCLUSIONS

If prognostic information is required in a patient with vocal fold paralysis that is more than 4 weeks and less than 6 months in duration, then LEMG should be performed. LEMG may be performed to clarify treatment decisions for vocal fold immobility that is presumed to be caused by RLN. Muscle Nerve 53: 850-855, 2016.

Anterior Cervical Spine Surgery for Degenerative Disease: A Review

Anterior cervical spine surgery is an established surgical intervention for cervical degenerative disease and high success rate with excellent long-term outcomes have been reported. However, indications of surgical procedures for certain conditions are still controversial and severe complications to cause neurological dysfunction or deaths may occur. This review is focused mainly on five widely performed procedures by anterior approach for cervical degenerative disease; anterior cervical discectomy, anterior cervical discectomy and fusion, anterior cervical corpectomy and fusion, anterior cervical foraminotomy, and arthroplasty. Indications, procedures, outcomes, and complications of these surgeries are discussed.

Constructing three-dimensional detachable and composable computer models of the head and neck

The head and neck region has a complex spatial and topological structure, three-dimensional (3D) computer model of the region can be used in anatomical education, radiotherapy planning and surgical training. However, most of the current models only consist of a few parts of the head and neck, and the 3D models are not detachable and composable. In this study, a high-resolution 3D detachable and composable model of the head and neck was constructed based on computed tomography (CT) serial images. First, fine CT serial images of the head and neck were obtained. Then, a color lookup table was created for 58 structures, which was used to create anatomical atlases of the head and neck. Then, surface and volume rendering methods were used to reconstruct 3D models of the head and neck. Smoothing and polygon reduction steps were added to improve 3D rendering effects. 3D computer models of the head and neck, including the sinus, pharynx, vasculature, nervous system, endocrine system and glands, muscles, bones and skin, were reconstructed. The models consisted of 58 anatomical detachable and composable structures and each structure can be displayed individually or together with other structures.

Anterior cervical discectomy in a patient with huge thyroid tissue (goiter)

Enlarged thyroid gland (goiter) may hinder to reach anterior part of the vertebrae or may impose more retraction than usual. The patient had left arm pain, and his left biceps muscle strength was 3/5 and triceps muscle strength was 4/5. Physical examination of his neck showed no abnormality. We performed anterior cervical discectomy, but we did not reach to the anterior part of the vertebrae due to enlarged thyroid gland even making moderately forceful medial retraction. It is therefore, we performed thyroidectomy previously, and later we performed anterior cervical discectomy at the level of cervical 5-6 and cervical 6-7. It will be wise to excise the goiter and later continue to cervical discectomy rather than using forceful retraction in cases with no preoperative detection as in our case to prevent damage of the recurrent laryngeal nerve and hoarseness due to pressure effect of the medial retraction during the anterior cervical approach.

Vocal cord palsy after anterior cervical spine surgery: a qualitative systematic review

BACKGROUND CONTEXT

Vocal cord palsy (VCP) is a known complication of anterior cervical spine surgery. However, the true incidence and interventions to minimize this complication are not well studied.

PURPOSE

To conduct a systematic review to identify the incidence, risk, and interventions for VCP after anterior cervical spine surgery.

STUDY DESIGN

This is a qualitative systematic literature review.

SAMPLE

Prospective and retrospective trials of patients undergoing anterior cervical spine surgery that reported on postoperative VCP or recurrent laryngeal nerve palsy.

OUTCOME MEASURES

Primary: incidence of VCP after anterior cervical spine surgery; secondary: risk factors and interventions for prevention of VCP after anterior cervical spine surgery.

METHODS

Electronic searches were conducted on Ovid Medline, EMBASE, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systemic Reviews for clinical studies reporting VCP in anterior cervical spine surgery, limited to studies published between 1995 and June 2013 in English and French languages. After selection of studies independently by two review authors, data on incidence, risk, and interventions were extracted. Qualitative analysis was performed on three domains: quality of studies, strength of evidence, and impact of interventions.

RESULTS

Our search has identified 187 abstracts, and 34 studies met our inclusion criteria. The incidence of VCP ranges from 2.3% to 24.2%. Significant heterogeneity in study design and definition of VCP were used in the published studies. There is good evidence that reoperation increases the risk of VCP. One study of moderate strength suggests that operating from the right side may increase the risk of VCP. Among the interventions studied, endotracheal tube (ETT) cuff pressure monitoring with deflation during retraction has shown to reduce the incidence from 6% to 2%, but this result was not confirmed by randomized control trials. Limited evidence exists for other interventions of intraoperative electromyographic monitoring and methylprednisolone.

CONCLUSIONS

Vocal cord palsy is a significant morbidity after anterior cervical surgery with incidence up to 24.2% in the immediate postoperative period, with a higher risk in reoperation of the anterior cervical spine. Moderate evidence exists for ETT cuff pressure adjustment in preventing this complication.

Esophageal, pharyngeal and hemorrhagic complications occurring in anterior cervical surgery: Three illustrative cases

Background:

The number of esophageal and pharyngeal perforations occurring in anterior cervical surgeries ranges from 0.25% to 1% and 0.2% to 1.2%, respectively. Symptoms usually appear postoperatively and are attributed to: Local infection, fistula, sepsis, or mediastinitis. Acute postoperative hematoma, although very rare (<1%), is the first complication to rule out due to its life-threatening complications (e.g. acute respiratory failure).

Case Description:

Over a 36-year period, the author(s) described three severe esophageal/pharyngeal complications attributed to anterior cervical surgery. As these complications were appropriately recognized/treated, patients had favorable outcomes.

Conclusions:

Anterior cervical spine surgery is a safe approach and is associated with few major esophageal/pharyngeal complications, which most commonly include transient dysphagia and dysphonia. If symptoms persist, patients should be assessed for esophageal/pharyngeal defects utilizing appropriate imaging studies. Notably, even if the major complications listed above are adequately treated, optimal results are in no way guaranteed.

Factors Predictive of Voice and Swallowing Outcomes after Anterior Approaches to the Cervical Spine

Objective

To quantify the incidence of postoperative voice, swallowing, and other problems, including time to resolution following anterior transcervical approaches to the cervical spine, and to assess surgical factors associated with outcomes.

Study Design

Historical cohort study.

Setting

Academic medical center.

Subjects and Methods

One hundred eighty-eight consecutive patients with cervical spine disease who underwent an anterior transcervical approach to the spine by a single head and neck surgeon over a 4-year time period. Rather than primary, single-level approaches, all patients in this study had multilevel, high-cervical (above C4), low-cervical (below C6), and/or revision approaches. Postoperative voice, swallowing, and other complaints were measured as well as time to resolution using Kaplan-Meier method. Surgical factors related to outcomes were analyzed using regression analysis.

Results

Follow-up was available for 129 patients, with average and median time of 35 months. Seventy-seven patients (60%) had a postoperative issue, including 35 patients (27%) with postoperative voice complaint, 62 patients (48%) with postoperative swallowing complaint, and 16 patients (12%) with other problems. Swallowing and voice complaints persisted beyond 1 year in 28% and 9% of patients, respectively. Approaching spinal levels above C4 and exposing more than 3 spinal levels were 2 factors significantly related to voice and swallowing problems.

Conclusion

There is a high incidence of subjective voice and swallowing complaints following transcervical anterior approaches to the spine, and such complaints can persist beyond 1 year in many patients. Exposure of more than 3 spinal levels or above level C4 are 2 factors significantly associated with outcome.

Long-term result of vocal cord paralysis after anterior cervical disectomy

PURPOSE

Anterior cervical disectomy and fusion (ACDF) is a highly effective and safe method for spinal cord and cervical root decompression. However, vocal cord paralysis (VCP) remains an important cause of postoperative morbidity. The true incidence and recovery course of postoperative VCP is still uncertain. This study is a report on VCP after ACDF to evaluate the incidence, recovery course, and possible risk factors.

METHODS

From 2004 to 2008, 1,895 consecutive patients underwent ACDF in our hospital and were followed up for at least 3 years. All surgeons were well trained and used a right-sided exposure. Prolonged VCP, where patients suffered from postoperative VCP lasting more than 3 months, was recorded and analyzed.

RESULTS

In this retrospective study, 9 of the 1,895 patients (0.47%) documented prolonged VCP lasting over 3 months. Six of the nine patients had total recovery within 9 months. Only three patients (0.16%) still had symptoms even after 3 years postoperatively. All symptoms of VCP, except hoarseness, could be improved. After matching with 36 non-VCP patients, no differences with regard to longer operative or anesthesia time, shorter neck, obesity, and prevertebral edema. All cases of prolonged course of postoperative VCP occurred in patients who underwent exposure at the C67 level.

CONCLUSION

In our study, only 0.47% documented prolonged postoperative VCP, while most patients recovered within 9 months. However, if symptoms last longer, there could be almost permanent VCP (0.16%). In our study, choking and dysphagia subsided mostly within 6 months, but hoarseness remained. The exposure of the C67 level obviously was a risk factor for postoperative VCP.

Incidence, risk factors, and mortality associated with aspiration in cervical spine surgery

STUDY DESIGN

Retrospective national database analysis.

OBJECTIVE

A population-based database was analyzed to characterize the incidence, mortality, and associated risk factors for aspiration pneumonia in cervical spine surgery.

SUMMARY OF BACKGROUND DATA

Aspiration pneumonia represents a potentially fatal complication of any surgical procedure. The incidence of this complication is not well characterized after cervical spine surgery.

METHODS

Data from the Nationwide Inpatient Sample was obtained from 2002-2009. Patients undergoing anterior cervical fusion, posterior cervical fusion, or posterior cervical decompression for radiculopathy and/or myelopathy were identified. Patient demographics, incidence of aspiration, costs, and mortalities were assessed. Statistical analysis was performed using Student t test for discrete variables and χ test for categorical data. Logistic regression was used to identify independent predictors for aspiration.

RESULTS

A total of 202,694 patients were identified in the Nationwide Inpatient Sample from 2002 to 2009. Of these, 166,633 were anterior cervical fusions (82.2%), 13,298 were posterior cervical fusions (6.6%), and 22,764 were posterior cervical decompressions (11.2%). The overall incidence of aspiration was 5.3 events per 1000 cases. The greatest incidence was demonstrated in posterior cervical fusion-treated patients with 13.7 per 1000 cases, followed by posterior cervical decompressions with 6.4 per 1000 and anterior cervical fusions with 4.5 per 1000. Patients affected by aspiration were significantly older, more frequently male, and had greater comorbidities than unaffected patients (P < 0.001). Patients diagnosed with aspiration demonstrated significantly greater length of stay, costs, and mortality (P < 0.001). Logistic regression analysis demonstrated independent predictors of aspiration to include advanced age (≥65 yr), male sex, congestive heart failure, coagulopathy, neuropsychiatric disorders, and weight loss (P < 0.001).

CONCLUSION

We demonstrated an overall incidence of 5.3 cases of aspiration per 1000 cervical procedures. Patients most commonly affected by aspiration were older males with greater comorbidity. Hospital courses complicated by aspiration had greater length of stay, costs, and mortality. Identification of patients with risk factors for aspiration may assist in early diagnosis and treatment to prevent further morbidity and mortality.

How to reduce recurrent laryngeal nerve palsy in anterior cervical spine surgery: a prospective observational study

BACKGROUND

Recurrent laryngeal nerve palsy (RLNP) occurs as a complication during anterior cervical spine surgery. In 2005 the authors demonstrated the high incidence of asymptomatic RLNP in a right-sided approach.

OBJECTIVE

This follow-up prospective observational study was designed to test 2 options said to reduce the rate of RLNP: reduced endotracheal cuff pressure and sinistral approach.

METHODS

Two hundred forty-two patients in whom anterior cervical spine surgery was performed were examined postoperatively with indirect laryngoscopy to evaluate the status of the vocal cords. All patients had a left-sided approach but 1 group (A, 149 patients) was operated on with an additional reduction of endotracheal cuff pressure to below 20 mm Hg. In 93 patients we could not reduce the cuff pressure. This group served as a control group (B). Both groups were compared with a historic control group with a right-sided approach and no cuff pressure reduction. In cases of vocal cord malfunction a follow-up examination was done 3 months later.

RESULTS

Group A (low cuff pressure) had a total rate of persisting symptomatic and asymptomatic RLNP of 1.3% and group B had a rate of 6.5% (normal cuff pressure). Compared with the historic study (N = 120) with a right-sided approach and a total rate of persisting RLNP of 13.3% in the left-sided approach, a marked reduction to 6.5% and 1.3% with an additional reduction of cuff pressure was seen.

CONCLUSION

The left-sided approach in anterior cervical spine surgery reduces the incidence of postoperative and permanent RLNP significantly. Endotracheal cuff pressure reduction used additionally decreases the rate of RLNP even more. These results indicate that anterior cervical spine surgery should be performed with a left-sided approach and, if possible, with an additional reduction of the endotracheal cuff pressure while the retractors are inserted.

Outpatient anterior cervical discectomy and fusion for cervical disk disease: a prospective consecutive series of 96 patients

OBJECTIVES

To evaluate surgical complications and clinical outcome in a consecutive series of 96 patients undergoing anterior cervical discectomy and fusion (ACDF) for cervical disk degeneration (CDD) in an outpatient setting.

METHODS

Pre-, per-, and postoperative data on patients undergoing single- or two-level outpatient ACDF at the private Oslofjord Clinic were prospectively collected.

RESULTS

This study includes 96 consecutive patients with a mean age of 49.1 years. 36/96 had a two-level ACDF. Mean postoperative observation time before discharge was 350 min, and 95/96 were successfully discharged either to their home or to a hotel on the day of surgery. The surgical mortality was 0%, while the surgical morbidity rate was 5.2%. Two (2.1%) patients developed postoperative hematoma, 2 (2.1%) patients experienced postoperative dysphagia, and 1 (1%) experienced deterioration of neurological function. Radicular pain, neck pain, and headache decreased significantly after surgery. 91% of patients were satisfied with the surgery, according to the NASSQ.

CONCLUSION

ACDF in carefully selected patients with CDD appears to be safe in the outpatient setting, provided a sufficient postoperative observation period. The clinical outcome and patient satisfaction of outpatients are comparable to that of inpatients.

Dysphagia and soft-tissue swelling after anterior cervical surgery: a radiographic analysis

BACKGROUND CONTEXT

Dysphagia is common in the early postoperative period after anterior cervical discectomy and fusion (ACDF). Several mechanisms, including soft-tissue swelling, have been implicated as a cause of postoperative dysphagia.

PURPOSE

To determine whether anterior soft-tissue swelling is greater in patients with postoperative dysphagia.

STUDY DESIGN

Prospective cohort study.

PATIENT SAMPLE

Forty-three patients.

OUTCOME MEASURES

Validated dysphagia questionnaire, lateral cervical spine radiographs.

METHODS

Patients undergoing one- or two-level ACDF using allograft bone and anterior instrumentation were enrolled. Baseline patient demographic characteristics and history were recorded. A dysphagia questionnaire, including a dysphagia numeric rating scale (DNRS; range, 0-10), was administered preoperatively and 2 and 6 weeks postoperatively. Lateral cervical radiographs were obtained preoperatively and 2 and 6 weeks postoperatively. The anterior cervical soft-tissue shadow width was measured at each level. Patients were divided into groups based on the 2-week dysphagia questionnaire: Group 1 (no symptoms/mild dysphagia) and Group 2 (moderate/severe dysphagia). Anterior soft-tissue shadow width at each level was compared between groups. Correlation was used to assess the relationship between DNRS and anterior soft-tissue swelling.

RESULTS

Forty-three patients (24 females; average age, 47.9) were enrolled. Fifteen patients had one-level and 28 patients had two-level ACDF. The anterior soft-tissue shadow width increased significantly from preoperative values at all levels except C1 at 2 and 6 weeks and C2 at 6 weeks. At 2 weeks, 18 patients had no symptoms/mild dysphagia (Group 1) and 25 patients had moderate/severe dysphagia (Group 2). The average DNRS was 1.1 for Group 1 and 5.3 for Group 2 (p<.001). This difference decreased by 6 weeks but remained significant. There were no significant differences in the soft-tissue measurements between groups at any level. There was no significant correlation between the DNRS and anterior soft-tissue swelling at any time point.

CONCLUSIONS

There is a significant increase in anterior cervical soft-tissue swelling after ACDF. The width of prevertebral soft-tissue does not correlate with postoperative dysphagia.

Clinically relevant anatomy of recurrent laryngeal nerve

STUDY DESIGN

An anatomic study of anterior cervical dissection of 11 embalmed cadavers.

OBJECTIVE

To determine the anatomic relationship of the recurrent laryngeal nerve (RLN) to the cervical spine and demonstrate vulnerability of the nerve during anterior surgical approach.

SUMMARY OF BACKGROUND DATA

The most common complications of anterior neck surgery are dysphagia and RLN palsy. The morbidity of these complications has led to the investigation of the impact of sidedness in anterior cervical spine surgery.

METHODS

Eleven adult cadavers (5 male/6 female) were dissected bilaterally to expose the path of the recurrent laryngeal nerve.

RESULTS

The right RLN branched from the vagus nerve at the level of T1-T2 or inferior in all specimens. After looping around the subclavian artery, the right RLN became invested in the tracheoesophageal fascia greater than 0.5 cm inferior to C7-T1 in all specimens. The RLN traveled superiorly, slightly anterior to the tracheoesophageal groove, before coursing between the trachea and the thyroid. In 82% (9 of 11) of right-sided dissections, the RLN entered the larynx at or inferior to C6-C7. After looping around the aortic arch, the left RLN was invested in the tracheoesophageal fascia inferior to the T2 level in 100% (10 of 10) of cadavers. The nerve traveled slightly anterior to the tracheoesophageal groove and within the tracheoesophageal fascia before coursing between the trachea and thyroid. In all the left-sided dissections, the RLN entered the larynx at or inferior to C6-C7.

CONCLUSION

This study found that superior to C7-T1, both RLNs had similar anatomic courses and received similar protection via surrounding soft-tissue structures. From an anatomic perspective, the authors did not appreciate a side-to-side difference superior to this level that could place either nerve under greater risk for injury.

Clinically relevant anatomy of high anterior cervical approach

STUDY DESIGN

An anatomic study of anterior cervical dissection of 11 embalmed cadavers and measurement of structures relative to cervical spine.

OBJECTIVE

To determine the anatomic relationship of the hypoglossal nerve (HN), internal and external superior laryngeal nerves (ESLNs), superior thyroid artery (STA), and superior laryngeal artery (SLA) to cervical spine and demonstrate any vulnerability.

SUMMARY OF BACKGROUND DATA

The anterior approach is a common approach to the cervical spine. Much of the operative morbidity in high cervical region is related to neurovascular injury leading to dysphagia, dysphonia, impaired high-pitch phonation, and impaired cough reflex.

METHODS

Eleven adult cadavers (5 male/6 female) were dissected bilaterally to expose structures of the high anterior cervical region.

RESULTS

The HN consistently traveled toward the midline at C2-3 and was safe caudal to C3-4. In 95% of dissections, the internal superior laryngeal nerve (ISLN) was exposed within 1 cm of C3-4. The path of the ESLN was variable, but it was safe above C3-4 and below C6-7. The ESLN was deep to the STA, and it was less bulky and tauter than the ISLN in all dissections. The origin of the STA was quite variable along the carotid artery, but it was most commonly located at C4. Two anatomic variants of the SLA were observed. In 15 dissections, the SLA branched off the superior thyroid. In six dissections, the SLA branched directly from external carotid artery. There was no appreciable side-to-side variation in the neurovascular structures studied.

CONCLUSION

On the basis this study, spine surgeons can have enhanced knowledge of high anterior cervical anatomy. The neurovascular structures in this study did not demonstrate side-to-side anatomic variation; therefore, patient pathology and surgeon preference should dictate the operative side.