Laryngeal reinnervation using ansa cervicalis for thyroid surgery-related unilateral vocal fold paralysis: a long-term outcome analysis of 237 cases

New strategy for intraoperative phonosurgical management of recurrent laryngeal nerve infiltrated by thyroid carcinoma

PURPOSE

Treating an infiltration of the recurrent laryngeal nerve (RLN) by thyroid carcinoma remains a subject of ongoing debate. Therefore, this study aims to provide a novel strategy for intraoperative phenosurgical management of RLN infiltrated by thyroid carcinoma.

METHODS

Forty-two patients with thyroid carcinoma infiltrating the RLN were recruited for this study and divided into three groups. Group A comprised six individuals with medullary thyroid cancer who underwent RLN resection and arytenoid adduction. Group B consisted of 29 differentiated thyroid cancer (DTC)patients who underwent RLN resection and ansa cervicalis (ACN)-to-RLN anastomosis. Group C included seven patients whose RLN was preserved.

RESULTS

The videostroboscopic analysis and voice assessment collectively indicated substantial improvements in voice quality for patients in Groups A and B one year post-surgery. Additionally, the shaving technique maintained a normal or near-normal voice in Group C one year post-surgery.

CONCLUSION

The new intraoperative phonosurgical strategy is as follows: Resection of the affected RLN and arytenoid adduction is required in cases of medullary or anaplastic carcinoma, regardless of preoperative RLN function. Suppose RLN is found infiltrated by well-differentiated thyroid cancer (WDTC) during surgery, and the RLN is preoperatively paralyzed, we recommend performing resection the involved RLN and ACN-to-RLN anastomosis immediately during surgery. If vocal folds exhibit normal mobility preoperatively, the MACIS scoring system is used to assess patient risk stratification. When the MACIS score > 6.99, resection of the involved RLN and immediate ACN-to-RLN anastomosis were performed. RLN preservation was limited to patients with MACIS scores ≤ 6.99.

Facial nerve communication with ansa cervicalis - An unusual anatomical variation

Neural connections of the seventh cranial nerve with its neighboring nerves are common and well documented; however, communication with ansa cervicalis is as yet unknown. We present a case with such a connection found during cadaveric dissection, with hitherto unknown consequences. In this specimen, after giving the marginal mandibular and cervical branches, the cervicofacial division continued distally to communicate with the distal loop of ansa cervicalis. Presence of such connection may result in facial muscle paralysis on injury to the ansa or strap muscle paralysis on injury to the facial nerve, depending on the direction of nerve fibers. Such unusual connections bring to light the need for extreme care during surgeries in the neck to safeguard any such connections and when using the ansa as donor.

Minimally Invasive Murine Laryngoscopy for Close-Up Imaging of Laryngeal Motion during Breathing and Swallowing

The larynx is an essential organ in mammals with three primary functions - breathing, swallowing, and vocalizing. A wide range of disorders are known to impair laryngeal function, which results in difficulty breathing (dyspnea), swallowing impairment (dysphagia), and/or voice impairment (dysphonia). Dysphagia, in particular, can lead to aspiration pneumonia and associated morbidity, recurrent hospitalization, and early mortality. Despite these serious consequences, existing treatments for laryngeal dysfunction are largely aimed at surgical and behavioral interventions that unfortunately do not typically restore normal laryngeal function, thus highlighting the urgent need for innovative solutions. To bridge this gap, we have been developing an experimental endoscopic approach to investigate laryngeal dysfunction in murine (i.e., mouse and rat) models. However, endoscopy in rodents is quite challenging due to their small size relative to current endoscope technology, anatomical differences in the upper airway, and the necessity for anesthesia to optimally access the larynx. Here, we describe a novel transoral laryngoscopy approach that permits close-up, unobstructed video imaging of laryngeal motion in mice and rats. Critical steps in the protocol include precise anesthesia management (to prevent overdosing that abolishes swallowing and/or risks respiratory distress-related mortality) and micromanipulator control of the endoscope (for stable video recording of laryngeal motion by a single researcher for subsequent quantification). Importantly, the protocol can be performed over time in the same animals to study the impact of various pathological conditions specifically on laryngeal function. A novel advantage of this protocol is the ability to visualize airway protection during swallowing, which is not possible in humans due to epiglottic inversion over the laryngeal inlet that obstructs the glottis from view. Rodents therefore provide a unique opportunity to specifically investigate the mechanisms of normal versus pathological laryngeal airway protection for the ultimate purpose of discovering treatments to effectively restore normal laryngeal function.

Systematic review and meta-analysis of laryngeal reinnervation techniques in adults with unilateral and bilateral vocal fold palsies

OBJECTIVE

To evaluate the outcomes of reinnervation techniques for the treatment of adult unilateral vocal fold paralysis and bilateral vocal fold paralysis.

METHODS

A literature review was conducted in the Embase and Medline databases in English, with no limitations on the publication date. The outcome parameters of interest included visual, subjective perceptual, acoustic, aerodynamic analysis and electromyography. A meta-analysis with a random-effects model and inverse variance was calculated.

RESULTS

The systematic Preferred Reporting Items for Systematic Reviews and Meta-Analyses approach resulted in 27 studies, totalling 803 patients (747 unilateral cases and 56 bilateral cases). Thyroid cancer and/or surgery had caused unilateral vocal fold paralysis in 74.8 per cent of cases and bilateral vocal fold paralysis in 69.6 per cent of cases. Statistically significant improvements in patients were observed for voice, deglutition and decannulation (bilateral vocal fold paralysis). Meta-analysis of 10 reinnervation techniques was calculated for the maximum phonation time of 184 patients.

CONCLUSION

Reinnervation was shown to improve voice, swallowing and decannulation, but studies lacked control groups, limiting generalisability. Larger studies with controls are needed.

Primary Nonselective Laryngeal Reinnervation in Iatrogenic Acute Recurrent Laryngeal Nerve Injury: Case Series and Literature Review

Treating an acutely injured recurrent laryngeal nerve by primary nonselective laryngeal reinnervation (LR) during thyroidectomy is encouraged to minimize postoperative morbidity. Performing a concurrent transoral temporary injection laryngoplasty (IL) may improve the patient's voice while waiting for the effect of successful reinnervation. Chronological multidimensional voice outcomes (qualitative and quantitative) and combination of the primary nonselective LR with concurrent transoral IL were not explicitly demonstrated in previous cases that published the literature. In this study, the authors presented the multidimensional voice parameters of 3 patients undergoing primary nonselective LR with concurrent IL during thyroidectomy. The parameters were measured at different time points (2 weeks and 1, 3, 6, and 12 months) following the surgery. Laryngeal electromyography was done at 1 to 2 months and 12 months postsurgery. The results showed that the voices, qualitatively and quantitatively, were within normal range at within 3 months postintervention. The parameters were slightly beyond the normal limit at 3 months and returned to normal at 6 months postintervention and beyond. The LEMG depicted evidence of successful reinnervation in which the motor unit was normal comparable to the opposite normal vocal fold.

Does the Severity of Vocal Fold Paresis on Laryngeal Electromyography Correlate With Radiographic Findings on Cross Sectional Imaging?

OBJECTIVES

Unilateral vocal fold paresis or paralysis (UVFP) is a condition for which radiographic evaluation and laryngeal electromyography (LEMG) are valuable to evaluate severity of injury and direct treatment plans. Despite extensive research involving findings suggestive of UVFP with radiographic imaging, no study has attempted to determine which findings suggestive of UVFP on imaging are clinically significant and suggest a need for intervention. The purpose of this study was to evaluate whether the severity of vocal fold paresis/paralysis affects the likelihood of encountering radiographic findings suggestive of UVFP. We also aimed to determine which findings suggestive of UVFP on imaging were clinically significant and were associated with surgical intervention.

MATERIALS AND METHODS

A retrospective chart review was conducted of patients who had been diagnosed with unilateral vocal fold paresis or paralysis and had been evaluated by CT scan and/or magnetic resonance imaging and laryngeal electromyography (EMG) between the dates of January 1, 2017 and January 9, 2018. Fisher's exact testing with Monte Carlo Simulation was utilized to determine statistical significance of identified relationships. Univariate analysis was conducted to assess for individual relationships between imaging results and the potential predictor variables. Chi square analysis was conducted with the various categorical variables to assess for any potential relationships to imaging results. Statistical significance was determined utilizing chi square analysis.

RESULTS

After data collection, 130 patients were included in the study population. Of the 112 patients with documented MRI results, 17% had a reported imaging abnormality suggestive of true vocal fold paresis or paralysis (VFP). Of the 71 patients with documented CT Neck results, 15.4% had an abnormality potentially concerning for true VFP. The average decrease in recruitment of the right and left SLN was 23.8% and 26.1%, respectively. The average decrease in recruitment of the right and left RLN was 37.3% and 57.78%, respectively. Seventy four percent of patients who exhibited abnormal MRI were found to have isolated SLN weakness, and 21% of patients were found to have a combined SLN and ipsilateral RLN weakness. In patients with abnormal CT scans 45% were found to have isolated SLN weakness, and 35% were found to have a combined SLN and RLN weakness. MRI imaging again failed to display any significant degree of paresis. However, abnormal CT results displayed severe CN X paresis in 36.84% vs 1.96% in normal scans. The chance of an abnormal MRI and CT result was 2.78 and 5.55 times greater, respectively, for each increase in the degree of severity of CN X paresis. When looking at the ability of imaging to predict the chance of a patient undergoing surgery, 34.8% of patients with an abnormal MRI underwent surgery compared to just 14.61% of those with normal scans. For CT scans, 35% of patients with an abnormal scan underwent surgery, compared with only 15.69% with normal imaging. When pooled, over 33% of patients with any abnormal imaging underwent a laryngeal procedure compared to 13% of patients with normal imaging.

CONCLUSIONS

There is a relationship between severity of vocal fold paresis found on laryngeal EMG and likelihood of detection on imaging. While CT was more likely to find characteristics of UVFP than MRI, patients who had an abnormal finding on either modality were more likely to undergo surgical intervention. These findings highlight the importance of early referral of patients with abnormal laryngeal imaging to an otolaryngologist for evaluation and possible intervention.

Selective ansa cervicalis nerve transfer to the marginal mandibular nerve for lower lip reanimation: An anatomical study in cadavers and a case report

BACKGROUND

Donor nerve options for lower lip reanimation are limited in patients undergoing oncological resection of the facial nerve. The ansa cervicalis nerve (ACN) is an advantageously situated donor with great potential but has not been examined in detail. In the current study, the anatomical technical feasibility of selective ACN to marginal mandibular nerve (MMN) transfer for restoration of lower lip tone and symmetry was explored. A clinical case is presented.

METHODS

Dissections were conducted in 21 hemifaces in non-embalmed human cadavers. The maximal harvestable length of ACN was measured and transfer to MMN was simulated. A 28-year-old male underwent ACN-MMN transfer after parotidectomy (carcinoma) and was evaluated 12 months post-operatively (modified Terzis' Lower Lip Grading Scale [25 observers] and photogrammetry).

RESULTS

The harvestable length of ACN was 100 ± 12 mm. A clinically significant anatomical variant ("short ansa") was present in 33% of cases (length: 37 ± 12 mm). Tensionless coaptation was possible in all cases only when using a modification of the surgical technique in "short ansa" cases (using an infrahyoid muscle nerve branch as an extension). The post-operative course of the clinical case was uneventful without complications, with improvement in tone, symmetry, and function at the lower lip at 12-month post-operative follow-up.

CONCLUSIONS

Selective ACN-MMN nerve transfer is anatomically feasible in facial paralysis following oncological ablative procedures. It allows direct nerve coaptation without significant donor site morbidity. The clinical case showed good outcomes 12 months post-operatively. A strategy when encountering the "short ansa" anatomical variant in clinical cases is proposed.

Demographic differences in the treatment of unilateral vocal fold paralysis

Objective

To determine the impact of patient demographics and social determinants of health on treatment pathways for unilateral vocal fold paralysis (UVFP) at a tertiary laryngology clinic.

Study design

Retrospective medical record review.

Methods

Patient demographics (age, gender, race, ethnicity, and insurance status) were extracted for adults diagnosed with UVFP between 2009 and 2019. Odds ratios for the associations between sociodemographic factors and UVFP treatment pathways were determined by chi-square analyses.

Results

A total of 1490 UVFP diagnoses were identified during the study period with the majority being female (58%), White (85%), non-Hispanic (97%), and publicly insured (54%). Five treatment pathways were identified: observation, injection laryngoplasty, voice therapy, laryngeal framework surgery/thyroplasty, and reinnervation surgery. There were 538 patients who underwent observation, 512 injection laryngoplasty, 366 voice therapy, 136 thyroplasty, and 26 laryngeal reinnervation surgery. Males were more likely to undergo injection laryngoplasty than females (OR 1.32; CI 1.08-1.61), whereas females were more likely to undergo voice therapy (OR 1.39; CI 1.09-1.76). Patients with public insurance (OR 1.48; CI 1.03-2.14) and Hispanics (OR 2.60; CI 1.18-5.72) were more likely to undergo thyroplasty. Patients who underwent reinnervation surgery were younger than those in other treatment pathways (median: 39.1 years vs. 50.7-56.1 years).

Conclusions

Gender, ethnicity, and insurance status were significantly associated with specific UVFP treatment pathways. Patients with public insurance were more likely to undergo surgical intervention than voice therapy. This data overall supports differences in care pathway utilization for UVFP based on social determinants of health.

Level of evidence

Level IV.

Donors for nerve transplantation in craniofacial soft tissue injuries

Neural tissue is an important soft tissue; for instance, craniofacial nerves govern several aspects of human behavior, including the expression of speech, emotion transmission, sensation, and motor function. Therefore, nerve repair to promote functional recovery after craniofacial soft tissue injuries is indispensable. However, the repair and regeneration of craniofacial nerves are challenging due to their intricate anatomical and physiological characteristics. Currently, nerve transplantation is an irreplaceable treatment for segmental nerve defects. With the development of emerging technologies, transplantation donors have become more diverse. The present article reviews the traditional and emerging alternative materials aimed at advancing cutting-edge research on craniofacial nerve repair and facilitating the transition from the laboratory to the clinic. It also provides a reference for donor selection for nerve repair after clinical craniofacial soft tissue injuries. We found that autografts are still widely accepted as the first options for segmental nerve defects. However, allogeneic composite functional units have a strong advantage for nerve transplantation for nerve defects accompanied by several tissue damages or loss. As an alternative to autografts, decellularized tissue has attracted increasing attention because of its low immunogenicity. Nerve conduits have been developed from traditional autologous tissue to composite conduits based on various synthetic materials, with developments in tissue engineering technology. Nerve conduits have great potential to replace traditional donors because their structures are more consistent with the physiological microenvironment and show self-regulation performance with improvements in 3D technology. New materials, such as hydrogels and nanomaterials, have attracted increasing attention in the biomedical field. Their biocompatibility and stimuli-responsiveness have been gradually explored by researchers in the regeneration and regulation of neural networks.

The Regenerative Effects of c-Met Agonistic Antibodies in Vocal Fold Atrophy

Background: Atrophy of the vocal folds and the accompanying glottic insufficiency affect the quality of life. Although growth factors have been used to treat muscle atrophy, their effectiveness is limited by their short half-life. Methods: In total, 15 rabbits and 24 rats were used for the study. The right recurrent laryngeal nerves of all animals were transected. One month following nerve transection, PBS (PBS group), rHGF (HGF group), or a c-Met agonistic antibody (c-Met group) was injected into the paralyzed vocal folds. The larynges of the rabbits were harvested from each group for histologic examination and subjected to PCR analysis. Results: Cross-sectional areas (CSAs) of thyroarytenoid muscles were evaluated. The c-Met group had increased CSAs compared to the PBS and HGF groups, but there were no significant differences compared to normal controls. The expression levels of myogenesis-related genes were evaluated three weeks after the injection. The expression levels of myosin heavy chain IIa were significantly increased in the PBS group, while the expression levels of MyoD were increased in the c-Met group. Conclusions: The c-Met agonistic antibody showed promise for promoting muscle regeneration in a vocal fold palsy model.

Timing of Ansa Cervicalis-to-recurrent Laryngeal Nerve Reinnervation: A Systematic Review

BACKGROUND

Ansa cervicalis-to-recurrent laryngeal nerve anastomosis (ARA) is an established technique for the treatment of recurrent laryngeal nerve (RLN) injury after head and neck surgery. However, the optimal timing of ARA remains unclear, and the evidence bases for ARA performed at each timepoint after RLN injury have not previously been clearly distinguished. We conducted a systematic review of the literature to evaluate the efficacy of ARA performed at different timepoints on postoperative voice outcomes.

METHODS

A review of English-language journal articles published in the last 20 years was undertaken on three electronic databases: Ovid MEDLINE, PubMed and Embase. Studies with a focus on paediatric RLN injury, bilateral RLN injury, ansa cervicalis anatomy and non-ARA techniques alone were excluded.

RESULTS

Twenty eight articles were included in the review. ARA was performed as a delayed surgery in 16/28 studies (57%), while immediate ARA was utilized in 14/28 studies (50%). On qualitative synthesis, delayed ARA was shown to be effective in improving patient-reported, subjective observer-reported and objective observer-reported voice outcomes. Likewise, a substantial body of evidence was identified demonstrating postoperative voice improvement with immediate ARA. On direct comparison of timepoints, some benefit was shown for early delayed ARA relative to late delayed operations, while no comparative data for immediate versus delayed repair were available in the literature.

CONCLUSIONS

ARA at both delayed and immediate timepoints is effective in the treatment of patients with RLN injury after head and neck surgery. The timing of ARA may have some influence on its efficacy, with early delayed repair potentially associated with superior outcomes to late delayed operations, and immediate ARA offering several practical advantages relative to delayed repair. Further comparative studies are required to better characterize the optimal timing of ARA after RLN injury.

Facial reanimation using the hypoglossal nerve and ansa cervicalis: a short-term retrospective analysis of surgical outcomes

Background

Transferring the hypoglossal nerve to the facial nerve using an end-to-end method is very effective for improving facial motor function. However, this technique may result in hemitongue atrophy. The ansa cervicalis, which arises from the cervical plexus, is also used for facial reanimation. We retrospectively reviewed cases where facial reanimation was performed using the ansa cervicalis to overcome the shortcomings of existing techniques of hypoglossal nerve transfer.

Methods

The records of 15 patients who underwent hypoglossal nerve transfer were retrospectively reviewed. Three methods were used: facial reanimation with hypoglossal nerve transfer (group 1), facial nerve reanimation using the ansa cervicalis (group 2), and sural nerve interposition grafting between the hypoglossal nerve and facial nerve (group 3). In group 1, the ansa cervicalis was coapted to neurotize the distal stump of the hypoglossal nerve in a subset of patients. Clinical outcomes were evaluated using the House-Brackmann (H-B) grading system and Emotrics software.

Results

All patients in group 1 (n = 4) achieved H-B grade IV facial function and showed improvements in the oral commissure angle at rest (preoperative vs. postoperative difference, 6.48° ± 0.77°) and while smiling (13.88° ± 2.00°). In groups 2 and 3, the oral commissure angle slightly improved at rest (group 2: 0.95° ± 0.53°, group 3: 1.35° ± 1.02°) and while smiling (group 2: 2.06° ± 0.67°, group 3: 1.23° ± 0.56°). In group 1, reduced tongue morbidity was found in patients who underwent ansa cervicalis transfer.

Conclusion

Facial reanimation with hypoglossal nerve transfer, in combination with hypoglossal nerve neurotization using the ansa cervicalis for complete facial palsy patients, might enable favorable facial reanimation outcomes and reduce tongue morbidity. Facial reanimation using the ansa cervicalis or sural nerve for incomplete facial palsy patients did not lead to remarkable improvements, but it warrants further investigation.

Twenty-One for 2021: The Most Influential Papers in Laryngology Since 2000

OBJECTIVES/HYPOTHESIS

To identify the most influential publications in laryngology since 2000.

STUDY DESIGN

Modified Delphi process.

METHODS

Samples of laryngologists drawn from editors of leading journals, organization officers, and thought leaders were invited to participate in a modified Delphi identification of influential laryngology papers. Influential was defined as follows: yielding meaningful practice changes, catalyzing further work as a foundation for an important topic, altering traditional views, or demonstrating durability over time. Quality and validity were not among the selection criteria. Each participant nominated 5 to 10 papers in Round 1. These nominations, augmented with papers from bibliometric analysis, were narrowed further in Round 2 as participants identified their top 20. The 40 papers with the most Round 2 votes were discussed by video conference and then subjected to Round 3 voting, with each participant again selecting their top 20 most influential papers. Final results were collated by the number of Round 3 votes.

RESULTS

Sixteen of 18 invited laryngologists participated overall (all 16 in Rounds 1 and 3; 14 in Round 2). Twenty-one papers were identified as most influential. One paper appeared on all 16 Round 3 lists; three papers with eight (50%) votes each were lasted to make the list. Eleven of these 21 focused on voice; three each related to cancer, airway, and swallowing; and one encompassed all of these clinical areas.

CONCLUSIONS

This list of 21 influential laryngology papers serves to focus further research, provides perspective on recent advances within the field, and is an educational resource for trainees and practicing physicians.

LEVEL OF EVIDENCE

N/A Laryngoscope, 2021.

Recovery of Vocal Cord Motion Among Pediatric Patients

OBJECTIVES

Patients with vocal cord paralysis can experience feeding, respiratory, and vocal problems leading to disability and decreased quality of life. Current evidence suggests waiting a period of 12 months for spontaneous recovery before permanent interventions. This study aims to determine the time to recover spontaneously and vocal cord movement in a pediatric population and create a model for evidence-based patient counseling.

STUDY DESIGN

Retrospective longitudinal cohort study.

METHODS

The report is a single institution longitudinal study on vocal cord paralysis recovery. Patients were categorized based on spontaneous recovery with vocal cord movement or no recovery. Recovery rates were determined using the Kaplan-Meier method.

RESULTS

Of 158 cases of vocal cord paralysis over a 4-year period, 36 had spontaneous recovery with symptom improvement and motion return. The average recovery was 8.8 months for those who recovered, and 78% recovered within 9 months. Two groups emerged from the data: an early recovery group with spontaneous recovery before 12 months and a late recovery group after 12 months. Children with dysphonia and paralysis due to cardiac surgery were less likely to recover, and children with aspiration were more likely to recover. Children with gastrointestinal comorbidities were less likely to recover; however, those who did recover were more likely to have recovered after 12 months. Based on our model, there is about a 3% chance of recovery between 9 and 12 months.

CONCLUSIONS

Patients should be counseled about earlier interventions. Waiting the conventional 12 months for only a 3% chance of spontaneous recovery without intervention or laryngeal EMG may not be the preferred option for some patients and their families.

Care and Management of Voice Change for Thyroid Surgery: Korean Society of Laryngology, Phoniatrics and Logopedics Clinical Practice Guideline

Voice change is a common complaint after thyroid surgery and has significant impacts on quality of life. The Korean Society of Laryngology, Phoniatrics, and Logopedics set up a task force team to establish guideline recommendations on education, care, and management related to thyroid surgery. The guideline recommendations include preoperative voice education, management of anticipated voice change during surgery, and comprehensive voice care after thyroid surgery, including in-depth information and up-to-date knowledge based on validated literature. The committee constructed 14 key questions (KQ) in three categories: preoperative (KQ1-2), intraoperative (KQ 3-8), and postoperative (KQ 9-14) management and developed 18 evidence-based recommendations. The Delphi survey reached an agreement on each recommendation. Detailed evidence profiles are presented for each recommendation. The level of evidence for each recommendation is classified into high, moderate, and low-quality. The recommendation's strengths are adjusted to consider the level of evidence resulting in the recommendation and are divided into strong and weak. The guidelines are primarily targeted toward physicians who treat thyroid surgery patients and speech-language pathologists participating in patient care. These guidelines will also help primary care physicians, nurses, healthcare policymakers, and patients improve their understanding of voice changes and voice care after thyroid surgery.

Medialization Laryngoplasty: A Review for Speech-Language Pathologists

Purpose The purpose of this study is to familiarize speech-language-pathologists with the current state of the science regarding medialization laryngoplasty in the treatment of voice disorders, with emphasis on current evidence-based practice, voice outcomes, and future directions for research. Method A literature review was performed in PubMed and Embase using the keywords vocal fold/cord and laryngoplasty, thyroplasty, augmentation, or laryngeal framework. Articles published between 2010 and 2020 were reviewed for data about clinical applications, technical approach, voice-related outcomes, and basic science or clinical innovations with the potential to improve patient care. A synthesis of data was performed from articles meeting the outlined search criteria. Conclusions As key members in the multidisciplinary care of voice disorders, speech-language pathologists need to be informed of current research in medialization laryngoplasty, a procedure commonly used for patients with glottic insufficiency. Advances in anesthetic technique, office-based procedures, and the development of materials with increased bio-tolerability over the past decade have led to innovations in treatment and improved patient outcomes. Recent applications of computational and bioengineering approaches have the potential to provide new directions in the refinement of currently available techniques and the improvement of patient-based treatment outcomes.

Using the larynx as a last resort for oral intake in a hypopharyngeal cancer patient

We present a new oral intake route in a hypopharyngeal cancer patient with severe complications. A 64-year-old man was diagnosed as having T2N0M0 squamous cell carcinoma of the posterior wall of the hypopharynx. He had previously undergone radiotherapy for laryngeal cancer and tricuspid valve replacement surgery, and also had atrial flutter and renal dysfunction. We performed surgery with curative intent. The hypopharynx was primarily closed after tumor resection. Laryngotracheal separation and tracheoesophageal diversion with end-to-end anastomosis of the trachea to the esophagus was performed. After surgery, complete oral feeding was achieved using the new pathway created. The larynx, contradictory to its typical role, can be used as a pathway to the esophagus using our revolutionary technique.

Early voice therapy for unilateral vocal fold paralysis improves subglottal pressure and glottal closure

PURPOSE

In cases of unilateral vocal fold paralysis (UVFP), voice disorders caused by glottic insufficiency can lead to a considerable reduction in the patient's quality of life. Voice therapy (VT) is an effective treatment that must be started early after the onset of vocal fold paralysis. This study examined the effect of early VT for patients with UVFP occurring after esophagectomy.

MATERIALS AND METHODS

Patients who had residual UVFP at 1 month postoperatively after esophagectomy for esophageal cancer between November 2014 and March 2017 were evaluated. Seventeen patients were divided into the VT group (n = 6) and non-VT group (n = 11). We compared these two groups and retrospectively examined the effect of early VT. The study endpoints included aerodynamic tests, laryngeal endoscopy, laryngeal stroboscopy, and glottal closure. All of these evaluations were performed at preoperatively and at 1 and 3 months postoperatively.

RESULTS

Subglottal pressure reduced notably in the VT group, and both the mean flow rate and maximum phonation time tended to improve after VT. Conversely, there were no significant differences in MFR and MPT in the non-VT group. Furthermore, although UVFP remained after VT, we achieved glottal closure for all three patients. Conversely, only two of the six patients with glottic insufficiency in the non-VT group achieved glottal closure.

CONCLUSION

VT may be effective for improving impaired vocal function in patients with UVFP. It is reasonable to expect that VT can be initiated 1 month after the onset of vocal fold paralysis.

Immediate Intraoperative Repair of the Recurrent Laryngeal Nerve in Thyroid Surgery

OBJECTIVES

Recurrent laryngeal nerve (RLN) injury is a recognized risk during thyroid and parathyroid surgery and can result in significant morbidity. The aim of this review paper is to consider the optimal approach to the immediate intraoperative repair of the RLN during thyroid surgery.

METHODS

A PubMed literature search was performed from inception to June 2020 using the following search strategy: immediate repair or repair recurrent laryngeal nerve, repair or reinnervation recurrent laryngeal nerve and immediate neurorraphy or neurorraphy recurrent laryngeal nerve.

RESULTS

Methods of immediate intraoperative repair of the RLN include direct end-to-end anastomosis, free nerve graft anastomosis, ansa cervicalis to RLN anastomosis, vagus to RLN anastomosis, and primary interposition graft. Techniques of nerve repair include micro-suturing, use of fibrin glue, and nerve grafting. Direct micro-suture is preferable when the defect can be repaired without tension. Fibrin glue has also been proposed for nerve repair but has been criticized for its toxicity, excessive slow reabsorption, and the risk of inflammatory reaction in the peripheral tissues. When the proximal stump of the RLN cannot be used, grafting could be done using transverse cervical nerve, supraclavicular nerve, vagus nerve, or ansa cervicalis.

CONCLUSIONS

Current evidence is low-level; however, it suggests that when the RLN has been severed, avulsed, or sacrificed during thyroid surgery it should be repaired intraoperatively. The immediate repair has on balance more advantages than disadvantages and should be considered whenever possible. This should enable the maintenance of vocal cord tone, better and prompter voice recovery and avoidance of aspiration. Laryngoscope, 131:1429-1435, 2021.

Guidelines for the Management of Unilateral Vocal Fold Paralysis From the Korean Society of Laryngology, Phoniatrics and Logopedics

The Korean Society of Laryngology, Phoniatrics and Logopedics appointed a task force to establish clinical practice guidelines for the management of unilateral vocal fold paralysis (UVFP). These guidelines cover a comprehensive range of management-related factors, including the diagnosis and treatment of UVFP, and provide in-depth information based on current, up-to-date knowledge. Detailed evidence profiles are provided for each recommendation. The CORE databases, including OVID Medline, Embase, the Cochrane Library, and KoreaMed, were searched to identify all relevant papers, using a predefined search strategy. When insufficient evidence existed, expert opinions and Delphi questionnaires were used to fill the evidence gap. The committee developed 16 evidence-based recommendations in six categories: initial evaluation (R1–4), spontaneous recovery (R5), medical treatment (R6), surgical treatment (R7–14), voice therapy (R15), and aspiration prevention (R16). The goal of these guidelines is to assist general otolaryngologists and speech-language pathologists who are primarily responsible for treating patients with UVFP. These guidelines are also intended to facilitate understanding of the condition among other health-care providers, including primary care physicians, nurses, and policy-makers.

Giant toxic multinodular goiter with dyspnea: A case report

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This case report mainly focus on a case of 47-year old female with multinodular goiter.

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Fine Needle Aspiration Cytology needs to be done from the suspicious nodule.

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Toxic MNG is most effectively treated by total thyroidectomy, which achieves complete diminution from symptoms.

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Surgery for huge goiter is challenging particularly on difficult intubation, altered anatomy, supraglottic edema and adhesions.

Introduction

Toxic multinodular goiter (MNG) involves an enlarged thyroid gland, is a common cause of hyperthyroidism and when it is accompanied by obstructive symptoms such as dyspnea, it carries an indication for surgery.

Case presentation

We present a case of 47-year old female with multinodular goiter with a rapid increase in size within 2 years. She also reported palpitation, breathlessness on exertion, tachycardia and hand tremor. Computed tomography scan of the neck shows a gross enlargement of thyroid gland across both sides of the neck. The fine needle aspiration cytology and final histopathological examination were suggestive of MNG with adenomatous nodules and toxic changes respectively. A total thyroidectomy was performed and the gland was dissected successfully.

Discussion

Toxic MNG is most effectively treated by total thyroidectomy, which achieves complete diminution from symptoms.

Conclusion

Surgery for huge goiter is challenging and one should be careful about difficult intubation, altered anatomy and adhesions to the surrounding structures. Recognizing and treating this kind of cases are important, as they constitute a preventable cause of mortality if timely diagnosed and treated.

Selective vagus-recurrent laryngeal nerve anastomosis in thyroidectomy with cancer invasion or iatrogenic transection

PURPOSE

Immediate recurrent laryngeal nerve (RLN) reconstruction at the time of thyroid cancer extirpation can provide excellent postoperative phonatory function. This study is to present our experience with the methods of RLN reconstruction, and to evaluate the role of selective vagus to RLN anastomosis (SVR) in thyroidectomy.

METHODS

Respective review of RLN reconstruction in thyroid surgery from January 2004 to October 2018 was conducted in two tertiary referral academic medical centers. Immediate RLN reconstruction was performed for primary thyroidectomy patients with intraoperative nerve tumor invasion or iatrogenic transection. Laryngofiberoscopic examination, voice evaluation of maximum phonation time, and GRBAS scale were performed preoperatively, on the second day after surgery, and monthly postoperatively for the first year.

RESULTS

A total of 37 patients were enrolled. Twenty-nine RLNs were resected caused by tumor-associated trauma; the other nerves were inadvertently transected. Direct anastomosis (DA) was performed in eight patients, free nerve graft (FNG) was performed in four patients, ansa cervicalis to RLN anastomosis (ARA) was performed in eight patients, and SVR was performed in 17 patients. The mean periods from the reinnervation surgery of DA, SVR, ARA, and FNG to the phonation recovery were 46 ± 19 (days), 41 ± 29 (days), 83 ± 21 (days), and 137 ± 32 (days), respectively. There were improvements in the GRBAS scale of perceptual voice quality at 1 month for DA and SVR, 2months for ARA.

CONCLUSIONS

Intraoperative SVR reinnervation demonstrated voice improvement postoperatively and might be an effective treatment for thyroidectomy-related permanent unilateral vocal cord paralysis.

Immediate Ansa Cervicalis-to-Recurrent Laryngeal Nerve Anastomosis for the Management of Recurrent Laryngeal Nerve Infiltration by a Differentiated Thyroid Carcinoma

OBJECTIVES

The optimal surgical approach to treat recurrent laryngeal nerve (RLN) infiltration by differentiated thyroid cancer (DTC) remains a subject of debate. This study explored the feasibility and efficiency of immediate ansa cervicalis nerve (ACN)-to-RLN anastomosis for the management of RLN infiltration by DTC.

MATERIAL AND METHODS

Fifty-three patients who underwent immediate ACN-to-RLN anastomosis during DTC extirpation were enrolled in the present study. Thirty-seven cases presented with unilateral vocal cord paralysis before the operation (Group A), and another 16 patients presented with normal vocal cord mobility preoperatively (Group B). Multidimensional assessments, videostroboscopy, voice assessment, and laryngeal electromyography (LEMG) were performed preoperatively and postoperatively.

RESULTS

All videostroboscopy, voice assessment and LEMG parameters in Group A deteriorated 1 month after the operation and improved 1 year after the operation compared with preoperative data. In Group B, all parameters 1 year after the operation improved significantly compared with the corresponding parameters 1 month after the operation. LEMG in Group A and B provided substantial evidence for the maturation of neural regeneration from ACN and demonstrated that the laryngeal muscles were reinnervated successfully by this procedure.

CONCLUSIONS

If the RLN is infiltrated by DTC, immediate ACN-to-RLN anastomosis during complete excision of DTC could restore satisfactory phonatory function and does not compromise oncological radicality.

Current landscape in motoneuron regeneration and reconstruction for motor cranial nerve injuries

The intricate anatomy and physiology of cranial nerves have inspired clinicians and scientists to study their roles in the nervous system. Damage to motor cranial nerves may result from a variety of organic or iatrogenic insults and causes devastating functional impairment and disfigurement. Surgical innovations directed towards restoring function to injured motor cranial nerves and their associated organs have evolved to include nerve repair, grafting, substitution, and muscle transposition. In parallel with this progress, research on tissue-engineered constructs, development of bioelectrical interfaces, and modulation of the regenerative milieu through cellular, immunomodulatory, or neurotrophic mechanisms has proliferated to enhance the available repertoire of clinically applicable reconstructive options. Despite these advances, patients continue to suffer from functional limitations relating to inadequate cranial nerve regeneration, aberrant reinnervation, or incomplete recovery of neuromuscular function. These shortfalls have profound quality of life ramifications and provide an impetus to further elucidate mechanisms underlying cranial nerve denervation and to improve repair. In this review, we summarize the literature on reconstruction and regeneration of motor cranial nerves following various injury patterns. We focus on seven cranial nerves with predominantly efferent functions and highlight shared patterns of injuries and clinical manifestations. We also present an overview of the existing reconstructive approaches, from facial reanimation, laryngeal reinnervation, to variations of interposition nerve grafts for reconstruction. We discuss ongoing endeavors to promote nerve regeneration and to suppress aberrant reinnervation and the development of synkinesis. Insights from these studies will shed light on recent progress and new horizons in understanding the biomechanics of peripheral nerve neurobiology, with emphasis on promising strategies for optimizing neural regeneration and identifying future directions in the field of motor cranial neuron research.

Main branch of ACN-to-RLN for management of laryngospasm due to unilateral vocal cord paralysis

OBJECTIVES/HYPOTHESIS

This study explored the feasibility and efficiency of main branch of ansa cervicalis nerve (ACN)-to-recurrent laryngeal nerve (RLN) anastomosis for management of paroxysmal laryngospasm due to unilateral vocal cord paralysis (UVCP).

METHODS

Thirteen patients who underwent main branch of ACN-to-RLN anastomosis for management of paroxysmal laryngospasm due to UVCP were enrolled in the present study. Multidimensional assessments, including videostroboscopy, voice assessment, and laryngeal electromyography (LEMG), were performed preoperatively and postoperatively.

RESULTS

This series was limited to UVCP with iatrogenic causes, including thyroidectomy, cervical spine surgery, and thoracic surgery. After main branch of ACN-to-RLN anastomosis, all cases showed significant airway improvement, and laryngospasm was completely abolished in 92.3% (12 of 13) of cases. Videostroboscopy showed that the bulging and paradoxical adduction of the affected vocal cord during a sniff were abolished immediately after operation, and there was no significant difference in vocal fold position or glottal closure before versus after the operation. LEMG showed that the postoperative recruitment and amplitude of voluntary motor unit potential in the affected thyroarytenoid muscle during a sniff were significantly decreased compared to preoperative values, and postoperative recruitment showed significant improvement during phonation compared to that preoperatively. Voice assessment showed that there were no significant differences in overall grade, roughness, breathiness, jitter (local), shimmer (local), noise-to-harmonics ratio, or maximum phonation time after the operation compared to the preoperative values.

CONCLUSIONS

Main branch of ACN-to-RLN anastomosis could have long-lasting efficacy in the management of paroxysmal laryngospasm due to UVCP, with no apparent compromise of voice quality.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:2412-2419, 2020.

Nonselective Laryngeal Reinnervation versus Type 1 Thyroplasty in Patients with Unilateral Vocal Fold Paralysis: A Single Tertiary Centre Experience

OBJECTIVE

This study compared the voice outcomes of selected patients with unilateral vocal fold palsy (UVFP) who underwent either nonselective laryngeal reinnervation (LR) or Type 1 thyroplasty (thyroplasty) in a Malaysian tertiary centre using multidimensional voice assessments.

PARTICIPANTS

The study included 16 patients with UVFP who underwent either LR (9 patients) or thyroplasty (7 patients) between 2015 and 2018 who fulfilled the inclusion criteria.

MAIN OUTCOME MEASURES

The outcomes were measured subjectively and objectively with: (1) voice handicap index-10 (VHI-10- Malay version); (2) auditory perceptual evaluation using the breathiness component of Grade, Roughness, Breathiness, Asthenia, Strain scale; (3) maximum phonation time (MPT); and (4) acoustic analysis (jitter%, shimmer%, and NHR) using OperaVOX^TM. The outcomes were measured at baseline, 6 and 12-months postoperative. The comparison of outcomes between pre and postoperative of each group was evaluated using one-way ANOVA test. Mann-Whitney test was used to compare the outcomes between the two groups.

RESULTS

Comparison of each group at different time points showed significant improvement of VHI-10 and MPT of LR group between baseline and 12 months (P ≤ 0.05) whereas, the improvement in thyroplasty group was observed at all time points (P ≤ 0.05). When comparing between the two groups at 12 months, the VHI-10 and MPT was significantly better in the LR group than thyroplasty group with P = 0.004 and P = 0.001 respectively. Other outcome measures did not reveal significant difference between the two groups.

CONCLUSION

This observational study showed that LR may be better than thyroplasty in improving VHI-10 and MPT in selected patients with UVFP.

An Anatomic Variant of the Ansa Cervicalis Precluding Its Use as a Donor Nerve

BACKGROUND

The ansa cervicalis is useful for cranial nerve repair, and may be harvested without apparent morbidity. Herein we report an unusual and surgically relevant anatomic variant of the ansa cervicalis.

METHODS

An adult male with left parotid adenoid cystic carcinoma underwent parotidectomy with upper-division facial nerve resection and planned interposition repair using the ansa cervicalis. The ipsilateral hypoglossal nerve was identified, together with a descending branch producing strap muscle contraction when stimulated. This presumed descendens hypoglossi was unusually large in caliber; further dissection revealed continuity with the vagus nerve.

RESULTS

Ansa cervicalis harvest was aborted when its separation from vagus nerve epineurium was not possible. The sural nerve was alternatively harvested. The patient awoke with left vocal fold palsy, which completely resolved within 3 months.

CONCLUSION

Anatomic variants of the ansa cervicalis exist that may preclude graft harvest and place the vagus nerve at risk of inadvertent injury.

Morphometric Differences in the Recurrent Laryngeal Nerve in Patients with Vocal Fold Paralysis

OBJECTIVES

Injury to the recurrent laryngeal nerve (RLN), if severe enough, can result in vocal fold paralysis. Reinnervation surgery can improve patient outcomes, but previous studies have reported a negative correlation between time since onset of paralysis and surgical outcomes. The ability of the paralyzed nerve to serve as a conduit for donor nerve fibers may be a factor in the success of reinnervation; however, changes in RLN composition after paralysis have not been well studied. Therefore, we investigated the morphometric composition of explanted RLN sections from patients who had experienced vocal fold paralysis for varying length of times.

METHODS

Nine nerve sections from unilateral vocal fold paralysis (UVP) patients and seven control nerve sections were analyzed for morphometric parameters including fascicular area, fiber count, fiber density, fiber packing, mean g-ratio, and fiber diameter distribution. Nerves from UVP patients were also compared as a function of time since UVP onset.

RESULTS

In comparison to control nerves, paralyzed nerves were found to have significantly lower fiber densities and fiber packing, higher mean g-ratio values, and a shift in diameter distributions toward smaller diameter fibers. With respect to paralysis duration, no significant differences were observed except in fiber diameter distributions, where those with paralysis for >2 years had distributions that were significantly shifted toward smaller diameter fibers.

CONCLUSIONS

The morphometric data presented here suggest that correlations between the time since onset of vocal fold paralysis and reinnervation outcomes may be due to fiber size changes in the paralyzed nerve over time.

Stroboscopic assessment of unilateral vocal fold paralysis: a systematic review

PURPOSE

To review the relevant basic stroboscopic evaluations in unilateral vocal fold paralysis (UVFP). Our aim was twofold: (1) to determine the frequency of use of stroboscopic parameters in outcome evaluation after surgical treatment of UVFP using a Pareto diagram; and (2) to select the most relevant parameters in terms of a significant difference between pre- and post-surgical intervention for UVFP.

METHODS

A systematic review in PUBMED includes studies on stroboscopic evaluation in combination with UVFP and surgical treatment. The review was limited to English studies published between 1990 and March 2018. The most frequently used stroboscopic parameters were identified using a Pareto diagram. Then, 'the percentage of significance' for the most frequently stroboscopic parameters was identified by comparing the number of studies that showed a statistically significant change in pre- and post-treatment results with the total number of studies using the same parameters.

RESULTS

Seven stroboscopic parameters were nominated using the Pareto diagram. In decreasing order of citation frequency, periodicity, edge bowing, mucosal wave, glottic gap, position of vocal fold, amplitude, and symmetry have respective percentages of significance of 87.5%, 83.3%, 77.7%, 64.5%, 60%, 57.1%, and 50%. Five pertinent scales were selected for the most frequent and significant stroboscopic parameters.

CONCLUSIONS

The results indicate that periodicity, edge bowing, mucosal wave, glottic gap, and position of vocal fold represent the five most frequently used and relevant stroboscopic parameters in UVFP evaluation. The current review outlines a proposal scale of these stroboscopic parameters.

PROSPERO REGISTRATION NUMBER

CRD42019126786.

Automated Quantification of Vocal Fold Motion in a Recurrent Laryngeal Nerve Injury Mouse Model

OBJECTIVES/HYPOTHESIS

The goal of this study was to objectively examine vocal fold (VF) motion dynamics after iatrogenic recurrent laryngeal nerve (RLN) injury in a mouse surgical model. Furthermore, we sought to identify a method of inducing injury with a consistent recovery pattern from which we can begin to evaluate spontaneous recovery and test therapeutic interventions.

STUDY DESIGN

Animal model.

METHODS

The right RLN in C57BL/6J mice was crushed for 30 seconds using an aneurysm clip with 1.3-N closing force. Transoral laryngoscopy enabled visualization of VF movement prior to surgery, immediately post-crush, and at two endpoints: 3 days (n = 5) and 2 weeks (n = 5). VF motion was quantified with our custom motion-analysis software. At each endpoint, RLN samples were collected for transmission electron microscopy for correlation with VF motion dynamics.

RESULTS

Our VF tracking software permitted automated quantification of several measures of VF dynamics, such as range and frequency of motion. By 2 weeks post-injury, the frequency of VF movement on the right (injured) side equaled the left, yet range of motion only partially recovered. These objective outcome measures enabled detection of VF dysfunction that persisted at 2 weeks post-crush. Transmission electron microscopy images revealed RLN degeneration 3 days post-crush and partial regeneration at 2 weeks, consistent with functional results obtained with automated VF tracking.

CONCLUSIONS

Our motion-analysis software provides novel objective, quantitative, and repeatable metrics to detect and describe subtle VF dysfunction in mice that corresponds with underlying RLN degeneration and recovery. Adaptation of our tracking software for use with human patients is underway.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:E247-E254, 2019.

Perspectives on voice treatment for unilateral vocal fold paralysis

PURPOSE OF REVIEW

Unilateral vocal fold paralysis (UVFP) is a common cause of neurogenic dysphonia resulting in glottal insufficiency. To restore glottal sufficiency and reduce the presenting dysphonia, treatment involving either surgical intervention, voice therapy or a combination of the two is typically provided. Currently, there is no consensus for the most effective voice treatment for UVFP. This results in an inability to compare current studies, and a lack of treatment effectiveness for the management of UVFP. This study aims to review the most recent literature for the management of dysphonia due to UVFP to establish the current evidence base for voice treatment options.

RECENT FINDINGS

There was found to be a lack of consistency in the rationale, selection and timing of the surgical intervention and/or voice therapy being provided for patients with UVFP.

SUMMARY

Further consensus is required for the rationale and selection of voice treatment prescriptions for the management of UVFP in order to improve treatment effectiveness and voice outcomes in patients with UVFP.

Recovery of Voice After Reconstruction of the Recurrent Laryngeal Nerve and Adjuvant Nimodipine

Background

Transection injury to the recurrent laryngeal nerve (RLN) has been associated with permanent vocal fold palsy, and treatment has been limited to voice therapy or local treatment of vocal folds. Microsurgical repair has been reported to induce a better function. The calcium channel antagonist nimodipine improves functional recovery after experimental nerve injury and also after cranial nerve injury in patients. This study aims to present voice outcome in patients who underwent repair of the RLN and received nimodipine during regeneration.

Methods

From 2002–2016, 19 patients were admitted to our center with complete unilateral injury to the RLN and underwent microsurgical repair of the RLN. After nerve repair, patients received nimodipine for 2–3 months. Laryngoscopy was performed repeatedly up to 14 months postoperatively. The Voice Handicap Index (VHI) was administered, and patients’ maximum phonation time (MPT) was recorded during the follow-up.

Results

All patients recovered well after surgery, and nimodipine was well tolerated with no dropouts. None of the patients suffered from atrophy of the vocal fold, and some patients even showed a small ab/adduction of the vocal fold on the repaired side with laryngoscopy. During long-term follow-up (>3 years), VHI and MPT normalized, indicating a nearly complete recovery from unilateral RLN injury.

Conclusions

In this cohort study, we report the results of the first 19 consecutive cases at our center subjected to reconstruction of the RLN and adjuvant nimodipine treatment. The outcome of the current strategy is encouraging and should be considered after iatrogenic RLN transection injuries.

Role of reinnervation in the management of recurrent laryngeal nerve injury: current state and advances

PURPOSE OF REVIEW

To present the current state of knowledge concerning different laryngeal reinnervation procedures for unilateral and bilateral vocal palsy.

RECENT FINDINGS

Recent reports show positive outcomes on both unilateral and bilateral reinnervations. The phrenic nerve is the most commonly used donor for bilateral vocal palsy, but use of the superior laryngeal nerve has also been suggested.

SUMMARY

Reinnervation of the larynx is a complex undertaking that can be performed by ENT surgeons with skills in microsurgery. Advances in this this field represent a paradigm shift in laryngeal rehabilitation and a prerequisite for laryngeal transplantation. Advances in basic understanding of nerve regeneration and in particular the need to surgically manage competitive reinnervation make the results of laryngeal reinnervation more predictable.

Computed tomographic assessment of autologous fat injection augmentation for vocal fold paralysis

Objective

To perform a quantitative computed tomography (CT) assessment of short‐ and long‐term outcomes of autologous fat injection augmentation in patients with unilateral vocal fold paralysis.

Study Design

Retrospective case series.

Methods

Twelve patients who had undergone autologous fat injection augmentation for unilateral vocal fold paralysis in our hospital between 2011 and 2015 were enrolled in this study. The autologous fat for injection was acquired from periumbilical subcutaneous tissue and was injected orally using a special‐purpose laryngeal injection needle. To evaluate the injected fat at the follow‐up assessments, CT was performed at several times after surgery in clinical practice. All thin‐section CT images were transferred to a workstation, and the volume of the injected fat was calculated.

Results

Patients comprised 6 men and 6 women with a mean age at the time of surgery of 62.9 years (range, 46–82 years). The actual injected fat volume was 1.1–2.5 ml (mean, 1.6 ml). In seven patients assessed by CT two days after surgery, the average residual rate of the injected fat was 63.9%. The mean residual rates of the injected fat were 30.0% at 3 months, 33.7% at 6 months, 29.2% at 12 months, and 32.0% at 24 months.

Conclusions

Although the injected fat volume decreased within the first three months and the residual rate of the injected fat was 30.0% at three months after injection, the residual fat volume remained at the same level for 24 months after injection.

Level of Evidence

4

Parameters and Scales Used to Assess and Report Findings From Stroboscopy: A Systematic Review

OBJECTIVE

Laryngeal endoscopy with stroboscopy, a critical component of the assessment of voice disorders, is rarely used as a treatment outcome measure in the scientific literature. We hypothesized that this is because of the lack of a widely used standardized, validated, and reliable method to assess and report laryngeal anatomy and physiology, and undertook a systematic literature review to determine the extent of the inconsistencies of the parameters and scales used in voice treatment outcome studies.

STUDY DESIGN

Systematic literature review.

METHODS

We searched PubMed, Ovid, and Cochrane for studies where laryngeal endoscopy with stroboscopy was used as a treatment outcome measure with search terms representing "stroboscopy" and "treatment" guided by Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement standards.

RESULTS

In the 62 included articles, we identified 141 terms representing 49 different parameters, which were further classified into 20 broad categories. The six most common parameters were magnitude of glottal gap, mucosal wave amplitude, location or shape of glottal gap, regularity of vibration, phase symmetry, and presence and size of specific lesions. Parameters were assessed on scales ranging from binary to 100 points. The number of scales used for each parameter varied from 1 to 24, with an average of four different scales per parameter.

CONCLUSIONS

There is a lack of agreement in the scientific literature regarding which parameters should be assessed to measure voice treatment outcomes and which terms and scales should be used for each parameter. This greatly diminishes comparison and clinical implementation of the results of treatment outcomes research in voice disorders. We highlight a previously published tool and recommend it for future use in research and clinical settings.

Speech therapy after thyroidectomy

Common complaints of patients who have received thyroidectomy include dysphonia (voice dysfunction) and dysphagia (difficulty swallowing). One cause of these surgical outcomes is recurrent laryngeal nerve paralysis. Many studies have discussed the effectiveness of speech therapy (e.g., voice therapy and dysphagia therapy) for improving dysphonia and dysphagia, but not specifically in patients who have received thyroidectomy. Therefore, the aim of this paper was to discuss issues regarding speech therapy such as voice therapy and dysphagia for patients after thyroidectomy. Another aim was to review the literature on speech therapy for patients with recurrent laryngeal nerve paralysis after thyroidectomy. Databases used for the literature review in this study included, PubMed, MEDLINE, Academic Search Primer, ERIC, CINAHL Plus, and EBSCO. The articles retrieved by database searches were classified and screened for relevance by using EndNote. Of the 936 articles retrieved, 18 discussed "voice assessment and thyroidectomy", 3 discussed "voice therapy and thyroidectomy", and 11 discussed "surgical interventions for voice restoration after thyroidectomy". Only 3 studies discussed topics related to "swallowing function assessment/treatment and thyroidectomy". Although many studies have investigated voice changes and assessment methods in thyroidectomy patients, few recent studies have investigated speech therapy after thyroidectomy. Additionally, some studies have addressed dysphagia after thyroidectomy, but few have discussed assessment and treatment of dysphagia after thyroidectomy.

Does laryngeal reinnervation or type I thyroplasty give better voice results for patients with unilateral vocal fold paralysis (VOCALIST): study protocol for a feasibility randomised controlled trial

INTRODUCTION

A functioning voice is essential for normal human communication. A good voice requires two moving vocal folds; if one fold is paralysed (unilateral vocal fold paralysis (UVFP)) people suffer from a breathy, weak voice that tires easily and is unable to function normally. UVFP can also result in choking and breathlessness. Current treatment for adults with UVFP is speech therapy to stimulate recovery of vocal fold (VF) motion or function and/or injection of the paralysed VF with a material to move it into a more favourable position for the functioning VF to close against. When these therapies are unsuccessful, or only provide temporary relief, surgery is offered. Two available surgical techniques are: (1) surgical medialisation; placing an implant near the paralysed VF to move it to the middle (thyroplasty) and/or repositioning the cartilage (arytenoid adduction) or (2) restoring the nerve supply to the VF (laryngeal reinnervation). Currently there is limited evidence to determine which surgery should be offered to adults with UVFP.

METHODS AND ANALYSIS

A feasibility study to test the practicality of running a multicentre, randomised clinical trial of surgery for UVFP, including: (1) a qualitative study to understand the recruitment process and how it operates in clinical centres and (2) a small randomised trial of 30 participants recruited at 3 UK sites comparing non-selective laryngeal reinnervation to type I thyroplasty. Participants will be followed up for 12 months. The primary outcome focuses on recruitment and retention, with secondary outcomes covering voice, swallowing and quality of life.

ETHICS AND DISSEMINATION

Ethical approval was received from National Research Ethics Service-Committee Bromley (reference 11/LO/0583). In addition to dissemination of results through presentation and publication of peer-reviewed articles, results will be shared with key clinician and patient groups required to develop the future large-scale randomised controlled trial.

TRIAL REGISTRATION NUMBER

ISRCTN90201732; 16 December 2015.

The natural history of recoverable vocal fold paralysis: Implications for kinetics of reinnervation

OBJECTIVES/HYPOTHESIS

Patients with unilateral vocal fold paralysis (UVFP) are commonly told to wait 12 months for spontaneous recovery. This study aims to 1) determine the time to vocal recovery in UVFP, 2) use that data to develop a neurophysiologically plausible model for recovery, and 3) use the model to generate meaningful predictions for patient counseling.

STUDY DESIGN

Case series with de novo mathematical modeling.

METHODS

Patients with UVFP who could pinpoint a discrete onset of vocal improvement were identified. The time-to-recovery data were modeled by assuming an "early" recovery group with neuropraxia and a "late" recovery group with more severe nerve injury. For the late group, a two-stage model was developed to explain the time to recovery: regenerating axons must cross the site of injury in stage 1 (probabilistic), followed by unimpeded regrowth to the larynx in stage 2 (deterministic).

RESULTS

Of 727 cases of UVFP over a 7-year period, 44 reported spontaneous recovery with a discrete onset of vocal improvement. A hybrid distribution incorporating the two stages (exponentially modified Gaussian) accurately modeled the time-to-recovery data (R² = 0.918). The model predicts 86% of patients with recoverable UVFP will recover within 6 months, with 96% recovering within 9 months. Earlier vocal recovery is associated with recovery of vocal fold motion and younger age.

CONCLUSIONS

Waiting 12 months for spontaneous recovery is probably too conservative. Repair across the site of injury, and not regrowth to larynx, is likely the rate-determining step in reinnervation, consistent with other works on peripheral nerve regeneration.

LEVEL OF EVIDENCE

4. Laryngoscope, 127:2585-2590, 2017.

Confirmation of an anatomic variation of the recurrent laryngeal nerve at site of entry into the larynx in Chinese population

OBJECTIVE

This study was aimed at analyzing the frequency of the newly reported variation and the frequency of postoperative palsy associated with three different kinds of known variations.

METHODS

We conducted a retrospective study on the data of 2068 consecutive Chinese patients who underwent thyroidectomy. The study included 1362 left and 1507 right (2869 in total) RLNs.

RESULTS

Among all the RLNs, 548 were found to have variations at the laryngeal entry of the RLN. The most frequent variation was extralaryngeal branching (n=322), followed by the fan-shaped branching (n=201). Our newly identified variation was also noted in 25 of our patients. In these cases, the RLN entered the larynx from sites that were distant from the posterior cricothyroid joint. The distance from the entry of the RLN to the back of cricothyroid joints was over 5mm. Compared to the rates reported from other countries, the rate of the first type of variation is lower, while that of the second type is higher. The frequency of the new variation has not been reported in other populations, but it is consistent with our previous finding. The incidence of postoperative palsy was greater for RLNs with the first and third types of variations than in the normal RLNs.

CONCLUSION

We confirmed that the incidence of patients with the new type of variation of the RLN at the entry of the larynx was about 1% in Chinese. Awareness among surgeons regarding this variation is important to avoid postoperative palsy.

Reliability of OperaVOX against Multidimensional Voice Program (MDVP)

OBJECTIVE

To evaluate the agreement between OperaVOX and MDVP.

DESIGN

Cross sectional reliability study.

SETTING

University teaching hospital.

METHODS

Fifty healthy volunteers and 50 voice disorder patients had supervised recordings in a quiet room using OperaVOX by the iPod's internal microphone with sampling rate of 45 kHz. A five-seconds recording of vowel/a/was used to measure fundamental frequency (F0), jitter, shimmer and noise-to-harmonic ratio (NHR). All healthy volunteers and 21 patients had a second recording. The recorded voices were also analysed using the MDVP. The inter- and intrasoftware reliability was analysed using intraclass correlation (ICC) test and Bland-Altman (BA) method. Mann-Whitney test was used to compare the acoustic parameters between healthy volunteers and patients.

RESULTS

Nine of 50 patients had severe aperiodic voice. The ICC was high with a confidence interval of >0.75 for the inter- and intrasoftware reliability except for the NHR. For the intersoftware BA analysis, excluding the severe aperiodic voice data sets, the bias (95% LOA) of F0, jitter, shimmer and NHR was 0.81 (11.32, -9.71); -0.13 (1.26, -1.52); -0.52 (1.68, -2.72); and 0.08 (0.27, -0.10). For the intrasoftware reliability, it was -1.48 (18.43, -21.39); 0.05 (1.31, -1.21); -0.01 (2.87, -2.89); and 0.005 (0.20, -0.18), respectively. Normative data from the healthy volunteers were obtained. There was a significant difference in all acoustic parameters between volunteers and patients measured by the Opera-VOX (P < 0.001) except for F0 in females (P = 0.87).

CONCLUSION

OperaVOX is comparable to MDVP and has high internal consistency for measuring the F0, jitter and shimmer of voice except for the NHR.

Effect of inhaled carbon dioxide on laryngeal abduction

Hypercapnia produces a profound effect on respiratory drive and upper airway function to maintain airway patency. Previous work has evaluated the effects of hypercapnia on the sole arytenoid abductor, the posterior cricoarytenoid (PCA), using indirect measures of function, such as electromyography and direct nerve recording. Here we describe a novel method to evaluate PCA function in anesthetized animals and use this method to determine the effects of hypercapnia on PCA function. Eight dogs were anesthetized, and a laryngeal mask airway was used, in combination with high-speed videoendoscopy, to evaluate laryngeal function. A stepwise increase in inspired partial pressure of CO2 produced marked arytenoid abduction above 70-mmHg end-tidal CO2 (ETCO2) ( P < 0.001). Glottic length increased above 80-mmHg ETCO2 ( P < 0.02), and this lead to underrepresentation of changes in glottic area, if standard measures of glottic area (normalized glottic gap area) were used. Use of a known scale to determine absolute glottic area demonstrated no plateau with increasing ETCO2 up to 120 mmHg. Ventilatory parameters also continued to increase with no evidence of a maximal response. In a second anesthetic episode, repeated bursts of transient hypercapnia for 60 s with an ETCO2 of 90 mmHg produced a 43–55% increase in glottic area ( P < 0.001) at or shortly after the end of the hypercapnic burst. A laryngeal mask airway can be used in combination with videoendoscopy to precisely determine changes in laryngeal dimensions with high temporal resolution. Absolute glottic area more precisely represents PCA function than normalized glottic gap area at moderate levels of hypercapnia.

Long-term efficacy of primary intraoperative recurrent laryngeal nerve reinnervation in the management of thyroidectomy-related unilateral vocal fold paralysis

CONCLUSION

Primary intraoperative recurrent laryngeal nerve (RLN) reinnervation techniques demonstrated significant voice improvement at 24 months postoperatively and could be an effective alternative treatment for thyroidectomy-related permanent unilateral vocal fold paralysis (VFP).

OBJECTIVES

To assess the long-term efficacy of intraoperative RLN reinnervation techniques in the management of thyroidectomy-related unilateral VFP.

METHODS

A prospective study was conducted from January 2008 to June 2012 at Soonchunhyang University Bucheon Hospital. Nineteen patients who underwent RLN reinnervation with either direct reinnervation (neurorrhaphy) or ansa cervicalis to RLN (ansa-RLN) anastomosis and completed subjective and objective voice measurement over a 1-year follow-up period were included in this study.

RESULTS

The causes of VFP were cancer involving the RLN (68.4%, 13/19) and iatrogenic nerve transection (31.5%, 6/19). Reinnervation techniques were direct neurorrhaphy (63.2%, 12/19) and ansa-RLN anastomosis (36.8%, 7/19). Subjective parameters such as the Voice Handicap Index (VHI), posterior glottic closure, and mucosal wave demonstrated significant improvement 6 months postoperatively, and the majority of parameters remained stable up to 24 months (p < 0.05). Objective parameters, such as maximum phonation time (MPT), jitter, shimmer, and the harmonics-to-noise ration (HNR), demonstrated significant improvement at 12 months and most remained stable at 24 months (p < 0.05).