Timing of nimodipine therapy for the treatment of vocal fold paralysis

Modern Surgical Techniques of Thyroidectomy and Advances in the Prevention and Treatment of Perioperative Complications

Thyroid cancer is the most common cancer of the endocrine system, and, in recent years, there has been a phenomenon of overdiagnosis followed by subsequent overtreatment. This results in an increasing number of thyroidectomy complications being faced in clinical practice. In this paper, we present the current state of knowledge and the latest findings in the fields of modern surgical techniques, thermal ablation, the identification and assessment of parathyroid function, recurrent laryngeal nerve monitoring and treatment and perioperative bleeding. We reviewed 485 papers, from which we selected 125 papers that are the most relevant. The main merit of this article is its comprehensive view of the subject under discussion-both general, concerning the selection of the appropriate method of surgery, and particular, concerning the selection of the appropriate method of prevention or treatment of selected perioperative complications.

Recurrent Laryngeal Nerve Paralysis Following Thyroidectomy: Analysis of Factors Affecting Nerve Recovery

OBJECTIVES

Paralysis of the recurrent laryngeal nerves (RLNs), albeit decreased over the years, leaves the surgeon helpless as there is not much that can be done once it occurs. Nimodipine has been suggested as a remedy that could accelerate the recovery of the nerve. Our study aimed to examine the factors that affect the recovery rate (RR) and time to recovery (TTR) of post-thyroidectomy RLN paralysis, with an emphasis on the use of nimodipine.

METHODS

A total of 197 patients who had undergone thyroid and parathyroid surgeries were retrospectively reviewed from October 2016 to August 2019. Patients who had RLN paralysis following surgery were assessed. The medical records were retrospectively analyzed to look for possible factors that may influence RLN recovery.

RESULTS

A total of 289 nerves were at risk. Temporary RLN paralysis rate was 7.9% while 1.7% was permanent. Age (odds ratio [OR] = 4.8) and intra-operative extra-thyroid extension (OR = 9.0) were independent risk factors for RLN paralysis. The rate of recovery was 82.1%. Loss of signal (LOS; P = .066) was a factor trending for an impact on RR but not nimodipine (P > .05). The mean TTR was 32 days. LOS, nimodipine, and steroid use, among others, were factors trending for an impact on the TTR.

CONCLUSION

Although not reaching statistical significance, nimodipine and steroids might influence TTR but not the RR. Larger studies are warranted to address the effect of nimodipine on the outcome of RLN paralysis.

LEVEL OF EVIDENCE

4 Laryngoscope, 2022.

Drug delivery to the pediatric upper airway

Pediatric upper airway disorders are frequently life-threatening and require precise assessment and intervention. Targeting these pathologies remains a challenge for clinicians due to the high complexity of pediatric upper airway anatomy and numerous potential etiologies; the most common treatments include systemic delivery of high dose steroids and antibiotics or complex and invasive surgeries. Furthermore, the majority of innovative airway management technologies are only designed and tested for adults, limiting their widespread implementation in the pediatric population. Here, we provide a comprehensive review of the most recent challenges of managing common pediatric upper airway disorders, describe the limitations of current clinical treatments, and elaborate on how to circumvent those limitations via local controlled drug delivery. Furthermore, we propose future advancements in the field of drug-eluting technologies to improve pediatric upper airway management outcomes.

Voice change after thyroidectomy without vocal cord paralysis: Analysis of 2,297 thyroidectomy patients

BACKGROUND

Some patients experience long-term voice change after thyroidectomy. One of the most common symptoms of voice change is pitch lowering, which is closely related to unfavorable voice quality. Here we observed voice outcomes for 6 months of follow-up after thyroidectomy to identify factors closely related to low-pitched voice.

METHODS

We retrospectively reviewed the records of 2,297 patients who underwent thyroidectomy between January 2014 and December 2017. All the patients had their vocal status examined using videostroboscopy, acoustic voice analyses, aerodynamic study, and Thyroidectomy-Related Voice Questionnaire scores. We stratified patients into 2 groups (low-pitched voice versus favorable voice) according to pitch lowering (reduction in speaking fundamental frequency ≥12 Hz 1 month after thyroidectomy compared to the preoperative value). We compared preoperative data with postoperative data collected 1, 3, and 6 months after thyroidectomy to identify factors contributing to low-pitched voice.

RESULTS

Univariate logistic regression analyses showed that factors related to low-pitched voice were female sex, older age, low body weight, short stature, and a high positive lymph node ratio. Multivariate analyses showed that female sex and older age were significantly associated with a negative prognosis for low-pitched voice 1 month after thyroidectomy (odds ratios 0.41 and 1.04, respectively; P < .001). Receiver operating characteristic curves for predicting sustained low-pitched voice during 6 months showed that speaking fundamental frequency ≥12.48 Hz 1 month after thyroidectomy was the optimal cutoff value, with 87.9% sensitivity and 95.8% specificity (P < .001).

CONCLUSION

Female sex and older age are strongly associated with increased risk for low-pitched voice after thyroidectomy. Speaking fundamental frequency ≥12.48 Hz 1 month after thyroidectomy can be used to predict sustained low-pitched voice after thyroidectomy.

The American Association of Endocrine Surgeons Guidelines for the Definitive Surgical Management of Thyroid Disease in Adults

OBJECTIVE

To develop evidence-based recommendations for safe, effective, and appropriate thyroidectomy.

BACKGROUND

Surgical management of thyroid disease has evolved considerably over several decades leading to variability in rendered care. Over 100,000 thyroid operations are performed annually in the US.

METHODS

The medical literature from 1/1/1985 to 11/9/2018 was reviewed by a panel of 19 experts in thyroid disorders representing multiple disciplines. The authors used the best available evidence to construct surgical management recommendations. Levels of evidence were determined using the American College of Physicians grading system, and management recommendations were discussed to consensus. Members of the American Association of Endocrine Surgeons reviewed and commented on preliminary drafts of the content.

RESULTS

These clinical guidelines analyze the indications for thyroidectomy as well as its definitions, technique, morbidity, and outcomes. Specific topics include Pathogenesis and Epidemiology, Initial Evaluation, Imaging, Fine Needle Aspiration Biopsy Diagnosis, Molecular Testing, Indications, Extent and Outcomes of Surgery, Preoperative Care, Initial Thyroidectomy, Perioperative Tissue Diagnosis, Nodal Dissection, Concurrent Parathyroidectomy, Hyperthyroid Conditions, Goiter, Adjuncts and Approaches to Thyroidectomy, Laryngology, Familial Thyroid Cancer, Postoperative Care and Complications, Cancer Management, and Reoperation.

CONCLUSIONS

Evidence-based guidelines were created to assist clinicians in the optimal surgical management of thyroid disease.

Laryngeal adductor function following potassium titanyl phosphate laser welding of the recurrent laryngeal nerve

OBJECTIVES/HYPOTHESIS

Recurrent laryngeal nerve (RLN) transection injuries may occur during thyroidectomy and other surgical procedures. Laser nerve welding has been shown to cause less technique-related axonal damage than the traditional suture method. We compared functional adductor results using these two methods of RLN repair.

STUDY DESIGN

Animal model.

METHODS

Canine hemilarynges underwent pretreatment testing of laryngeal adductor function, followed by RLN transection and repair using potassium titanyl phosphate (KTP) laser welding (n = 8) or microneural suture (n = 16) techniques. Six months later, adductor function was measured again and expressed as a proportion of the pretreatment value.

RESULTS

The mean laryngeal adductor pressure ratios were 82.4% (95% confidence interval [CI]: 72.8%-92.0%) for the laser repair group and 55.5% (95% CI: 49.4%-61.6%) for the suture control group, with a difference of 26.9% (95% CI: 15.3%-38.5%). Both spontaneous and stimulated glottic closure was observed in the laser welding and microsuture repair groups.

CONCLUSIONS

Laser nerve welding resulted in greater strength of adduction than suture repair of an acutely transected RLN. Suture anastomosis may traumatize more axons than the laser. Stronger vocal fold adduction is associated clinically with better protection from aspiration and improved voice outcomes. KTP laser welding should be considered for anastomosis of the RLN and other nerves.

LEVEL OF EVIDENCE

NA Laryngoscope, 130:1764-1769, 2020.

Awareness of Thyroid Surgeons on Voice and Airway Complications: An Attitude Survey in Turkey

INTRODUCTION

Thyroidectomy is one of the most commonly performed surgical procedures. Preoperative patient education and postoperative management of complications are vital to avoid postoperative medicolegal problems.

OBJECTIVE

The aim of this study was to assess the attitudes of thyroid surgeons about voice and airway complications of the surgery and the approaches used to avoid or handle these complications.

METHODS

A questionnaire based on surgeons' attitudes and behaviors on thyroidectomy was answered by 177 thyroid surgeons. Questions regarding demographic information, preoperative information methods, preoperative laryngeal examination, intraoperative nerve preservation techniques, and methods to avoid and handle postoperative complications were asked. Surgeons who completed the questionnaire were divided into three groups based on their annual volumes: less than 50 (low volume), 50-100 (middle volume), and more than 100 (high volume) for statistical analysis. The differences between the subgroups were compared using the chi-squared test.

RESULTS

During the preoperative disclosure, nearly all surgeons (97.2%) gave information about possible hoarseness; however, this high rate fell to 79.7% for possible voice changes, and to the lowest level of 36.7% for ability to change the voice pitch. Only 53.7% of the surgeons discussed the possibility of postoperative tracheostomy requirement. The surgeons with high annual volumes were found to perform vocal fold examination prior to a second surgery significantly higher than other groups (P=0.015). In the postoperative period, 84.2% of physicians indicated that they perform a laryngoscopic examination only for patients with voice problems. There was no statistically important difference between subgroups.

CONCLUSIONS

Our study is unique to provide information from the surgeons' perspective by evaluating preoperative patient information, and intraoperative and postoperative protective and curative methods. The training of residents and fellows who are expected to perform thyroidectomies can be revised to compromise all aspects of complications.

Long-term quality of voice is usually acceptable after initial hoarseness caused by a thyroidectomy or a parathyroidectomy

Background

Vocal cord (VC) palsy following a thyroidectomy or parathyroidectomy can result in significant morbidity for the patient. We aimed to investigate the incidence of VC palsy in a tertiary referral Institution, track the management of these cases and record the long-term outcomes and VC recovery rates.

Methods

Retrospective review of all thyroidectomy/parathyroidectomy operations performed over 11 years. Patients with an unequivocal hoarse voice postoperatively were included. We analysed the patient's clinical characteristics and voice outcomes, operative, pathology and laryngoscopy reports during their follow-up.

Results

Ten patients fitted the inclusion criteria and were analysed. Median age at date of operation was 47.5 years (range, 16-81 years) and the M:F ratio was 1:2.3 (M:3, F:7). The median FU was 62.5 months (range, 12-144 months). The median hospital stay was 1.5 days (range, 1-87 days). There were 7 recurrent laryngeal nerve (RLN) injuries by manipulation, 1 case of RLN resection, 1 inadvertent division (with primary nerve repair) and 1 RLN was shaved off the thyroid. Long-term voice outcomes for the 7 patients with an RLN manipulation injury were: 3/7 patients had normal voice, 3/7 had moderate hoarseness and 1/7 had long-term hoarseness. The long-term voice outcome of the patient with RLN shaving off the thyroid gland was excellent while the 2 remaining patients (RLN resection and inadvertent division) needed 12 and 18 months respectively to achieve a normal quality of voice. Four out of the 10 patients had permanent VC palsy in the long-term and their voice outcomes varied: 1 patient had a normal voice, 2 patients had moderate hoarseness and 1 patient had persistent hoarseness. Only 1/10 patients did not show any voice improvement after 12 months.

Conclusions

In the vast majority of cases post-operative hoarseness due to RLN palsy improves in the long-term, albeit voice may not return completely to normal.

Motor endplate-expressing cartilage-muscle implants for reconstruction of a denervated hemilarynx

OBJECTIVE

Tissue engineering of the larynx requires a complex, multiple tissue layer design. Additionally, spontaneous reinnervation of the larynx after recurrent laryngeal nerve (RLN) injury is often disorganized, resulting in subpar function. This study investigates use of tissue-engineered cartilage and motor endplate-expressing (MEE) tissue-engineered skeletal muscle implants for laryngeal reconstruction and the promotion of organized reinnervation after RLN injury.

METHODS

F344 rat primary muscle progenitor cells (MPCs) were isolated. Three-dimensional muscle constructs were created by encapsulating MPCs in type I oligomeric collagen under passive tension. Constructs were then cultured in differentiation medium (MPC control constructs) or induced to form motor endplates (MEE constructs) with neurotrophic agents. Three-dimensional cartilage constructs were created with adipose stem cells differentiated in chondrocyte medium. The muscle and cartilage constructs were implanted into surgically created myochondral defects in the F344 rat larynx with injured or intact (control) RLN. At 1-, 3-, and 6-month timepoints, videolaryngoscopy, electromyography (EMG), histology, and immunohistochemistry were used to assess outcomes.

RESULTS

At all timepoints, cartilage-muscle implants were well integrated into host tissue. Functionally, there was increased vocal fold adduction and EMG activity in nerve-injured rats treated with the MEE constructs when compared to those treated with the MPC control constructs. Motor endplate-expressing constructs had increased myofiber cross-sectional area compared to MPC control constructs.

CONCLUSION

Although our laboratory previously demonstrated that muscle and cartilage constructs could be used separately for hemilaryngeal reconstruction, this study suggests combining them with the modification of MEEs rather than MPCs, resulting in improved muscle recovery after recurrent laryngeal nerve injury.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:1293-1300, 2019.

Nimodipine for the treatment of otolaryngic indications

PURPOSE

The uses of nimodipine for otolaryngic indications are reviewed, and recommendations for its use in clinical practice are provided.

SUMMARY

Nimodipine is currently indicated for the improvement of neurologic outcomes in adult patients with aneurysmal subarachnoid hemorrhage (aSAH). However, other oral and i.v. calcium channel blockers have not exhibited the same beneficial effects in patients with aSAH, leading clinicians to believe that nimodipine possesses unique neuroprotective effects in addition to its calcium channel-blocking and vasodilatory properties. Consequently, clinical investigations of nimodipine have been conducted for cochlear and facial nerve preservation after vestibular schwannoma (VS) surgery, symptomatic management of Ménière's disease and peripheral vertigo, and recovery of vocal cord paralysis after laryngeal nerve injury. Three prospective randomized studies have investigated nimodipine for hearing and/or nerve preservation in patients undergoing VS resection, the results of which have suggested a potential benefit of initiating nimodipine during the perioperative period. Several studies of Ménière's disease and/or peripheral vertigo have reported improved symptom control with nimodipine. For vocal fold paralysis associated with recurrent laryngeal nerve (RLN) injury, nimodipine may increase the recovery rate based on the results of 1 nonrandomized prospective study that used nimodipine in a protocolized manner. One small pilot study found that nimodipine improved facial nerve function after maxillofacial surgery.

CONCLUSION

Due to its proposed vasoactive and neuroprotective effects, nimodipine may play a role in the treatment of a number of otolaryngic pathologies including VS, Ménière's disease, peripheral vertigo, RLN injury, and facial weakness after maxillofacial surgery. Small studies have shown improved symptom control and recovery after surgery. Since all of the aforementioned indications are still considered off label, clinicians and patients should collaboratively assess the risks and benefits before initiating treatment.

Surgical management of the recurrent laryngeal nerve in thyroidectomy: American Head and Neck Society Consensus Statement

"I have noticed in operations of this kind, which I have seen performed by others upon the living, and in a number of excisions, which I have myself performed on the dead body, that most of the difficulty in the separation of the tumor has occurred in the region of these ligaments…. This difficulty, I believe, to be a very frequent source of that accident, which so commonly occurs in removal of goiter, I mean division of the recurrent laryngeal nerve." Sir James Berry (1887).

Influence of Left-Right Asymmetries on Voice Quality in Simulated Paramedian Vocal Fold Paralysis

PURPOSE

The purpose of this study was to determine the vocal fold structural and vibratory symmetries that are important to vocal function and voice quality in a simulated paramedian vocal fold paralysis.

METHOD

A computational kinematic speech production model was used to simulate an exemplar "voice" on the basis of asymmetric settings of parameters controlling glottal configuration. These parameters were then altered individually to determine their effect on maximum flow declination rate, spectral slope, cepstral peak prominence, harmonics-to-noise ratio, and perceived voice quality.

RESULTS

Asymmetry of each of the 5 vocal fold parameters influenced vocal function and voice quality; measured change was greatest for adduction and bulging. Increasing the symmetry of all parameters improved voice, and the best voice occurred with overcorrection of adduction, followed by bulging, nodal point ratio, starting phase, and amplitude of vibration.

CONCLUSIONS

Although vocal process adduction and edge bulging asymmetries are most influential in voice quality for simulated vocal fold motion impairment, amplitude of vibration and starting phase asymmetries are also perceptually important. These findings are consistent with the current surgical approach to vocal fold motion impairment, where goals include medializing the vocal process and straightening concave edges. The results also explain many of the residual postoperative voice limitations.

Evaluation of Vocal Fold Motion Abnormalities: Are We All Seeing the Same Thing?

OBJECTIVES

Flexible laryngoscopy is the principle tool for the evaluation of vocal fold motion. As of yet, no consistent, unified outcome metric has been developed for vocal fold paralysis/immobility research. The goal of this study was to evaluate vocal fold motion assessment (inter- and intra-rater reliability) among general otolaryngologists and fellowship-trained laryngologists.

STUDY DESIGN

Prospective video perceptual analysis study.

METHODS

Flexible laryngoscopic examinations, with sound, of 15 unique patient cases (20 seconds each) were sent to 10 general otolaryngologists and 10 fellowship-trained laryngologists blinded to clinical history. Reviewers were given written definitions of vocal fold mobility and immobility and two video examples. The cases included bilateral vocal fold mobility (six), unilateral vocal fold immobility (five), and unilateral vocal fold hypomobility (four). Five examinations were repeated to determine intra-rater reliability. Participants were asked to judge if there was or there was no purposeful motion, as described by written definitions, for each vocal fold (800 tokens in total).

RESULTS

Twenty reviewers (100%) replied. Both general otolaryngologists and fellowship-trained laryngologists had an overall inter-rater reliability of 95%. Difference in inter-rater reliability between the two groups of raters was negligible: 95% for general otolaryngologists and 97.5% for fellowship-trained laryngologists. There was no variability in intra-rater reliability within either rater group (99%).

CONCLUSION

Intra- and inter-rater agreement in determining whether the patient had purposeful vocal fold motion on flexible laryngoscopic examination was excellent in both groups. This study demonstrates that otolaryngologists can consistently and accurately judge the presence and the absence of vocal fold motion.

Recovery of laryngeal function after intraoperative injury to the recurrent laryngeal nerve

Loss of function in the recurrent laryngeal nerve (RLN) during thyroid/parathyroid surgery, despite a macroscopically intact nerve, is a challenge which highlights the sensitivity and complexity of laryngeal innervation. Furthermore, the uncertain prognosis stresses a lack of capability to diagnose the reason behind the impaired function. There is a great deal of literature considering risk factors, surgical technique and mechanisms outside the nerve affecting the incidence of RLN paresis during surgery. To be able to prognosticate recovery in cases of laryngeal dysfunction and voice changes after thyroid surgery, the surgeon would first need to define the presence, location, and type of laryngeal nerve injury. There is little data describing the events within the nerve and the neurobiological reasons for the impaired function related to potential recovery and prognosis. In addition, very little data has been presented in order to clarify any differences between the transient and permanent injury of the RLN. This review aims, from an anatomical and neurobiological perspective, to provide an update on the current understandings of surgically-induced injury to the laryngeal nerves.