Vocal Fold Augmentation Research Articles

A novel silk-based vocal fold augmentation material: 6-month evaluation in a canine model.

Ideal long-term vocal fold augmentation materials should be biocompatible, easily administered, allow tissue integration for long-term effect, and remain at the site of injection. A novel silk protein particle suspended in hyaluronic acid (Silk-HA) has been developed specifically for vocal fold augmentation to address this unmet need. This article presents the 6-month, preclinical findings of a canine vocal fold injection trial for Silk-HA. Twelve beagle dogs were injected transorally in the lateral/deep aspect of their right thyroarytenoid muscles with 0.3 cc of Silk-HA or calcium hydroxylapatite in carboxymethyl cellulose (CaHA-CMC). The Silk-HA particle injectable was delivered via a custom catheter, whereas CaHA-CMC was delivered through a commercially available malleable needle. The six dogs from each material group were sacrificed 6 months from the injection date for the evaluation of implant longevity, immune response, and material migration. Silk-HA provides immediate medialization of the right vocal fold, lasting for a minimum of 6 months in a canine model. Silk-HA and CaHA-CMC both demonstrate similar inflammatory responses. The Silk-HA was shown to remain without migration at the site of injection in all six canine subjects, whereas CaHA-CMC demonstrated migration in four of the six canines. In two canines implanted with CaHA-CMC, material was discovered to migrate to the retropharyngeal lymph nodes. In a canine subject model, the Silk-HA material compares favorably in terms of longevity and immune response to CaHA-CMC. The lack of migration of the Silk-HA material demonstrates a promising potential for vocal fold injection in the clinic. NA Laryngoscope, 129:1856-1862, 2019.

Treatment of Patients with Vocal Fold Atrophy and Comorbid Essential Voice Tremor: Long-Term Injection Augmentation Outcomes After Successful Diagnostic Vocal Fold Injection Augmentation

Vocal fold injection augmentation (VFIA) is employed diagnostically for patients with subtle glottic insufficiency. Its use in patients with both vocal fold atrophy and benign essential voice tremor (EVT) has been reported but not after durable augmentation. This study intends to evaluate the success of durable VFIA using either autologous fat or calcium hydroxylapatite in patients with both vocal fold atrophy and comorbid EVT. Retrospective review. Subjects included demonstrated subtle glottic insufficiency from true vocal fold atrophy and comorbid EVT with no other vocal fold pathology. Voice Handicap Index (VHI-10), aerodynamic data including subglottic pressure and airflow, and the tremor scoring scale were evaluated before diagnostic VFIA with carboxymethylcellulose and after durable VFIA with calcium hydroxylapatite or autologous fat. Seven patients met inclusion criteria. Six subjects went on to durable VFIA. Three of six demonstrated meaningful improvement in the VHI-10 score. Subglottic pressure improved significantly in those subjects with meaningful VHI-10 improvement compared to those that did not. The tremor did not resolve completely in any subject, but patient satisfaction and function was improved in four of the six. VFIA for EVT in the setting of true vocal fold atrophy appears to offer benefit and may be an alternative treatment pathway for EVT patients. More than half of the subjects who underwent durable VFIA after successful diagnostic VFIA reported improvement in their communication despite inconsistent objective outcomes. Subglottic pressure improved significantly in half of the subjects who also reported a substantive improvement in their VHI-10.

Speech disorders in Parkinson's disease: pathophysiology, medical management and surgical approaches.

The prevalence of speech disorders among individuals with Parkinson's disease (PD) has been reported to be as high as 89%. Speech impairment in PD results from a combination of motor and nonmotor deficits. The production of speech depends upon the coordination of various motor activities: respiration, phonation, articulation, resonance and prosody. A speech disorder is defined as impairment in any of its inter-related components. Despite the high prevalence of speech disorders in PD, only 3-4% receive speech treatment. Treatment modalities include pharmacological intervention, speech therapy, surgery, deep brain stimulation and vocal fold augmentation. Although management of Parkinsonian dysarthria is clinically challenging, speech treatment in PD should be part of a multidisciplinary approach to patient care in this disease.

Decreased intramuscular calcium hydroxyapatite implant resorption in a murine model of osteoporosis.

Calcium hydroxyapatite (CaHA) is a common material for vocal fold injection augmentation. Durability is variable, and factors involved in implant longevity are not understood. Animal models of osteoporosis show decreased bone density and increased mineral liberation, suggesting CaHA retention may be altered in these conditions. Prospective murine investigation. Fourteen skeletally mature, 10-month-old female Sprague-Dewley rats were treated by one of three interventions: oophorectomy, laparotomy without oophorectomy (sham), or monthly risedronate injection (90 μg/kg, subcutaneous). CaHA was implanted into the right lateral thigh muscle in all animals at the time of procedure or first risedronate injection. After 17 weeks, all rats were sacrificed, and the residual CaHA isolated from excised lateral thigh muscle through incubation in a 900 °C calcinator for 9 hours. Mean CaHA mass remaining in the oophorectomy group was 65.9 (standard deviation ± 16.1) mg, compared to 44.4 ± 10.0 mg CaHA in the risedronate group and 48.6 ± 7.5 mg in the sham group. One-way analysis of variance found a statistically significant difference between the oophorectomy and risedronate groups but not between the sham and other groups, F(2,11) = 4.404, P = 0.039. Persistent estrogen deficiency in a murine model of osteoporosis demonstrated decreased rate of CaHA resorption. This suggests that hormone alterations associated with osteoporosis may alter the longevity of CaHA implant resorption through an uncertain mechanism. NA. Laryngoscope, 2576-2580, 2018.

Introduction

Since its inception with the invention of the laryngeal mirror and the early work of Horace Green, Chevalier Jackson, Johann Czermak, Morrell McKenzie, and others in the mid-19th Century, the field of laryngology has grown exponentially. With the introduction of suspension laryngoscopy and general anesthesia, surgeons were able to work with both hands. The addition of the operative microscope allowed visualization not previously possible. In the mid-20th Century, the CO2 laser permitted laryngeal surgery to performed with unprecedented precision and hemostasis. The 1970's saw the advent of flexible laryngoscopes and stroboscopy which took our diagnostic capabilities to new levels. The distal chip laryngoscopes which followed along with the fiber-based lasers, allowed procedures to be done in the office setting with superior visualization and exactness. And the story continues…… I am very excited to dedicate this issue of the World Journal of Otorhinolaryngology-Head and Neck Surgery to the subspecialty of Laryngology. It includes contributions from the US and abroad on topics encompassing many aspects of voice, airway, and swallowing disorders. Office based procedures are highlighted including an innovative approach to office based vocal fold augmentation presented by Dr. Hamdan and his colleagues from Lebanon. The study by Dr. Koshkareva and colleagues examines the risk of laryngotracheal stenosis in burn victims who require mechanical ventilation. The effect of injection laryngoplasty on swallowing function is elaborated upon by Drs. Anis and Memon, and the taste acceptability of commercial thickening agents used to treat patients with dysphagia is the focus of Dr. Yver and colleagues' work. Papers on pediatric arthrogryposis, technological advances in laryngoscopic image sharing and animal models for teaching laryngotracheal surgery are also included, as is an excellent study elucidating the presence of anxiety and depression in patient with spasmodic dysphonia. I invite you to read the entire issue in detail and am sure that you will find it both interesting and informative.

Injectable Silk Protein Microparticle-based Fillers: A Novel Material for Potential Use in Glottic Insufficiency

A novel, silk protein-based injectable filler was engineered with the intention of vocal fold augmentation as its eventual intended use. This injectable filler leverages the unique properties of silk protein's superior biocompatibility, mechanical tunability, and slow in vivo degradation to one day better serve the needs of otolaryngologists. This paper intends to demonstrate the mechanical properties of the proposed novel injectable and to evaluate its longevity in animal models. Experimental. The mechanical properties of silk bulking agents were determined to characterize deformation resistance and recovery compared with commercially available calcium hydroxylapatite through rheologic testing. Fresh porcine vocal fold tissue was used for injectable placement to simulate the mechanical outcomes of native tissue after bulking procedures. In vivo subcutaneous rodent implantation examined immune response, particle migration, and volume retention. Porous, elastomeric silk microparticles demonstrate high recovery (>90% original volume) from compressive strain and mimic the native storage modulus of soft tissues (1-3 kPa). Injectable silk causes only a slight increase in porcine vocal fold stiffness immediately after injection (20%), preserving the native mechanics of bulked tissue. In the subcutaneous rat model, silk demonstrated biocompatibility and slow degradation, thus enabling host cell integration and tissue deposition. The presented novel silk injectable material demonstrates favorable qualities for a vocal fold injection augmentation material. An in vivo long-term canine study is planned.

Perception and duration of pain after office-based vocal fold injection augmentation.

In-office laryngology procedures are important in the treatment of voice and swallowing disorders. Patient tolerance determines which procedures can be performed without sedation or formal anesthesia. This study examines pain perception during and after in-office vocal fold injection augmentation. Prospective cohort study. Patients scheduled for office-based vocal fold injection augmentation were prospectively enrolled at an academic voice center. The short-form McGill Pain Questionnaire was administered before, during, and after the procedure and on postprocedure days 1, 3, and 7. Pre- and postprocedure vital signs were recorded and heart rate was continuously monitored. Telephone questionnaires were completed on postprocedure days 1 and 3. Forty-five patients consented to participate in our study (24 males, mean age 61 years). Most patients experienced mild to moderate pain with increasing heart rate during the procedure. Pain remained or increased 20 minutes after the procedure and improved but persisted for 1 day. Sensory and affective discomfort was endorsed by the majority. A minority of patients experienced bruising and changes in swallowing with diet modification for 3 days after the procedure. Sixteen percent had discomfort after 1 week. This is the first prospective study examining patient perception of pain during and after in-office injection augmentation using a validated scale and pain descriptors with extended follow-up. The results may offer guidance for patient counseling, consent, and treatment to improve tolerance and success. 4. Laryngoscope, 128:929-934, 2018.

Evaluation of a Shorter Follow-up Time to Capture Benefit of a Trial Vocal Fold Augmentation

Trial vocal fold injection (TVFI) is employed diagnostically for patients with subtle glottic insufficiency to explore potential for improvement. Clinical experience demonstrates the time to and length of peak benefit of the TVFI is variable. Previous studies collected data 4 weeks or more after TVFI. The aim of this study was to compare subjectively successful and unsuccessful TVFI patient groups. It is hypothesized that patients with subjectively reported success will also have significant improvements in Voice Handicap Index-10 (VHI-10), phase closure percentage, and aerodynamic measures 2 weeks after trial augmentation. Subjects with glottic insufficiency were included in this retrospective review if they underwent office-based, per-oral vocal fold injection augmentation specifically for trial purposes. Patients were divided into "successful" and "unsuccessful" groups based on their subjective experience during the 2-week post-TVFI period. VHI-10, subjective report, phase closure evaluation using frame-by-frame analysis, and aerodynamic data were collected pre- and 2 weeks post-TVFI. Of the subjects, 15 of 23 (65%) reported a successful subjective improvement of their symptom, whereas 8 (35%) were unsuccessful (only partial improvement or no improvement). The number of subjects with an improvement in VHI-10 by 5 or more points was not significantly different between groups. The number of subjects that demonstrated complete, long phase closure was significantly higher in the successful group (P = 0.021). The understanding of how to more precisely determine the success of TVFI remains incomplete. Subjective improvement of successful TVFI was captured with basic clinical questioning, yet the VHI-10 was unable to confidently demonstrate this reported success 2 weeks after TVFI.

Using Trial Vocal Fold Injection to Select Vocal Fold Scar Patients Who May Benefit From More Durable Augmentation.

Clinical indications for vocal fold injection augmentation (VFI) are expanding. Prior studies demonstrate the benefit of trial VFI for select causes of glottic insufficiency. No studies have examined trial VFI for glottic insufficiency resulting from true vocal fold (TVF) scar. Retrospective chart review of patients who underwent trial VFI for a dominant pathology of TVF scar causing dysphonia. Patients who subsequently underwent durable augmentation were identified. The primary study outcome was the difference in Voice Handicap Index-10 (VHI-10) score from pretrial VFI to post-durable augmentation. Twenty-eight patients underwent trial VFI for TVF scar, 22 of whom reported a positive response. Fifteen of 22 subjects who underwent durable augmentation had viable data for analysis. Mean VHI-10 improved from 26.9 to 18.6 ( P < .05), for a delta VHI-10 of 8.3, or 30.9% improvement. Twelve of the 15 (80%) showed a clinically significant improvement (delta VHI-10 >5). A trial VFI is a potentially useful, low-risk procedure that appears to help the patient and clinician identify when global augmentation might improve the voice when vocal fold scar is present. Patients who reported successful trial VFI often demonstrated significant improvement in their VHI-10 after subsequent durable augmentation.

Vocal fold augmentation under local anaesthesia using autologous fascia

Vocal fold augmentation by injection of autologous fascia has been used since the 1990s with excellent safety record in 500 operations done under general anaesthesia. It is safe from risks arising from allergic or other foreign body adverse reactions. Fascia provides long-term augmentation and remains stable 3-10 years after injection. Vocal fold augmentation under local anaesthesia is excellent alternative for those unfit for general anaesthesia, providing aid to fragile and weak persons with vocal fold paralysis. However, all of available synthetic materials resorb within 6-24 months. Fascia injection under local anaesthesia provides the possibility for a long-term vocal fold medialization while avoiding risk of general anaesthesia. Fascia lata harvesting and processing is easily done (as shown in video) followed by injection into the vocal fold. The whole procedure is done under local anaesthesia. Procedure offers long-term vocal fold medialization, fine tuning the amount of the medialization by immediate feedback from the patient's voice. Operation time is one hour. This article is protected by copyright. All rights reserved.

Structural Fat Grafting to Improve Outcomes of Vocal Folds' Fat Augmentation: Long-term Results.

Objective Evaluating the long-term outcomes of vocal fold structural fat grafting. Study Design Case series with chart review. Setting University hospital. Subjects and Methods Seventy-nine dysphonic patients (16-82 years; 55 with unilateral laryngeal paralysis and 24 with vocal fold scarring) underwent vocal fold fat injection. Fat was harvested by low-pressure liposuction and then processed by centrifugation. Refined fat aliquots were placed in the vocal fold and paraglottic space in multiple tunnels to enhance graft neovascularization. All patients were followed for 12 months, 15 for 3 years, and 5 for 10 years with videolaryngostroboscopy, maximal phonation time (MPT) measurement, Voice Handicap Index (VHI) questionnaire, and GRBAS (grade, roughness, breathiness, asthenia, strain) perceptual evaluation. Laryngeal computed tomography (CT) and/or magnetic resonance imaging (MRI) studies were performed in 16 patients 3 to 28 months postoperatively; MRI was repeated in 5 cases 12 to 18 months after the first radiological study. Results The voice quality of all patients improved after surgery, and long-term stability was confirmed by MPT, GRBAS, and VHI ( P ranging between .004 and <.001). The results achieved 1 year postoperatively remained stable at 3 and 10 years. Videolaryn-gostroboscopy showed improved glottic closure in all patients despite a limited amount of fat resorption. CT and MRI demonstrated survival of the fat grafts in all of the 16 examined cases. Serial MRI scans showed no change in graft size over time. Conclusions The reported clinical and radiological data demonstrate that fat is an effective filler for permanent vocal fold augmentation if the refined micro-aliquots are placed in multiple tunnels.

The effect of vocal fold augmentation on cough symptoms in the presence of glottic insufficiency.

To determine the effect of injection augmentation of the vocal folds on chronic cough symptoms in patients with glottic insufficiency. Medical records from 146 consecutive patients who underwent vocal fold injection augmentation by a fellowship-trained laryngologist between 2013 and 2015 were reviewed. Twenty-three patients (12 male) met inclusion criteria of a vocal fold augmentation injection, cough symptoms lasting more than 8 weeks, and glottic insufficiency as determined by shortened closed phase on stroboscopy. Exclusion criteria included lack of cough complaints, diagnosis of vocal fold immobility, previous history of vocal fold augmentation, and incomplete data sets. Data collected included age, gender, pre- and 1-month postinjection Cough Severity Index (CSI) scores, location of injection (unilateral or bilateral), and patient statement of percent change in symptoms that was recorded at 1-month postinjection visit. Paired t test indicated a significant decrease in CSI scores from pre- (m = 18.5) to 1-month postinjection (m = 12.1) (P = 0.004). Eighteen patients (78.2%) reported a 50% or greater improvement in cough symptoms at the 1-month postinjection visit. Injection augmentation of the vocal folds in the presence of glottic insufficiency appears to improve cough symptoms, as was reported by CSI in patients who are refractory to other medical and behavioral treatments. 4. Laryngoscope, 128:1316-1319, 2018.

Impact of vocal fold augmentation and laryngoplasty on dyspnea in patients with glottal incompetence.

Given that the vocal folds are active organs of respiration, reports of dyspnea in the context of glottic insufficiency are not uncommon. We hypothesize that improved glottal closure via framework surgery or vocal fold augmentation improves dyspnea symptoms. Retrospective review. Charts of patients undergoing procedures to correct glottal insufficiency, either via vocal fold augmentation (VFA) or medialization laryngoplasty (ML) between December 2012 and September 2015 were reviewed (n = 189). Modified Borg Dyspnea Scale (MBDS) and Modified Medical Research Council Dyspnea Scale (MMRCDS) data were collected before and after intervention. Age, body mass index (BMI), and sex, as well as pulmonary and cardiac comorbidities were considered. Subgroup analysis was performed on individuals with subjective dyspnea prior to intervention. For the entire cohort, differences in the MMRCDS and MBDS were not statistically different pre- and postintervention (P = .20 and P = .12, respectively). Patients with BMI <30 experienced more improvement on the MBDS (P = .03). Both the MMRCDS and MMBDS improved post-procedure (P = .001 and P = .001, respectively) in patients reporting dyspnea prior to intervention. Patients with glottic insufficiency and dyspnea prior to intervention to improve glottic closure had a significant reduction in dyspnea following treatment. Conversely, subjects without complaints of dyspnea prior to intervention had variable outcomes with regard to dyspnea symptoms. Additionally, based on data from the entire cohort, VFA or ML did not worsen dyspnea symptoms. These data may assist in counseling and/or selection of patients considered for procedures to improve glottic closure. 4. Laryngoscope, 128:427-429, 2018.

Changes in Peak Airflow Measurement During Maximal Cough After Vocal Fold Augmentation in Patients With Glottic Insufficiency

Compromised cough effectiveness is correlated with dysphagia and aspiration. Glottic insufficiency likely yields decreased cough strength and effectiveness. Although vocal fold augmentation favorably affects voice and likely improves cough strength, few data exist to support this hypothesis. To assess whether vocal fold augmentation improves peak airflow measurements during maximal-effort cough following augmentation. This case series study was conducted in a tertiary, academic laryngology clinic. Participants included 14 consecutive individuals with glottic insufficiency due to vocal fold paralysis, which was diagnosed via videostrobolaryngoscopy as a component of routine clinical examination. All participants who chose to proceed with augmentation were considered for the study whether office-based or operative augmentation was planned. Postaugmentation data were collected only at the first follow-up visit, which was targeted for 14 days after augmentation but varied on the basis of participant availability. Data were collected from June 5, 2014, to October 1, 2015. Data analysis took place between October 2, 2015, and March 3, 2017. Peak airflow during maximal volitional cough was quantified before and after vocal fold augmentation. Participants performed maximal coughs, and peak expiratory flow during the maximal cough was captured according to American Thoracic Society guidelines. Among the 14 participants (7 men and 7 women), the mean (SD) age was 62 (18) years. Three types of injectable material were used for vocal fold augmentation: carboxymethylcellulose in 5 patients, hyaluronic acid in 5, and calcium hydroxylapatite in 4. Following augmentation, cough strength increased in 11 participants and decreased cough strength was observed in 3. Peak airflow measurements during maximal cough varied from a decrease of 40 L/min to an increase of 150 L/min following augmentation. When preaugmentation and postaugmentation peak airflow measurements were compared, the median improvement was 50 L/min (95% CI, 10-75 L/min; P = .01). Immediate peak airflow measurements during cough collected within 30 minutes of augmentation varied when compared with measurements collected at follow-up (103-380 vs 160-390 L/min). Peak airflow during maximal cough may improve with vocal fold augmentation. Additional assessment and measurements are needed to further delineate which patients will benefit most regarding their cough from vocal fold augmentation.

Medialization Laryngoplasty After Injection Augmentation

This study aims to assess the effect of vocal fold injection augmentation (IA) on subsequent medialization laryngoplasty (ML). A retrospective cohort study with follow-up telephone survey was carried out. Clinical records of patients with unilateral vocal fold paralysis or paresis (VFP) who underwent ML between April 2006 and March 2015 were reviewed. Patients who underwent IA before ML were compared with patients who did not, with respect to demographic information, symptoms, Voice Handicap Index-10 (VHI-10), etiology of VFP, and revision rate. Among patients undergoing IA, the effects of injection material and of interval from IA to ML on revision rate were assessed. Follow-up telephone surveys were conducted to evaluate long-term outcomes using VHI-10 and a condition-specific questionnaire. One hundred thirty-five patients (70 male:65 female) with vocal fold paralysis (125) or paresis (10) underwent ML (96 left:39 right). Sixty-six (48.9%) patients underwent concurrent arytenoid adduction. Fourteen (10.4%) patients required revision. Fifty-six (41.5%) patients had prior IA; five (8.9%) patients underwent revision. Seventy-nine (58.5%) patients did not have IA; nine (11.4%) patients required revision (P = 0.78). Neither augmentation material nor length of interval between last IA and ML affected the revision rate (P = 1.00; P ≥ 0.11 for all tested intervals, respectively). No difference in follow-up VHI-10 score was found between patients who had IA before ML and patients who had not (P = 0.73). IA does not appear to affect the revision rate or long-term outcome of subsequent ML.

Laryngeal reinnervation in unilateral vocal fold paralysis- case report and literature review

Laryngeal reinnervation is the method of treatment in unilateral vocal fold paralysis. During the surgery an anastomosis between the main branch of ansa cervicalis and recurrent laryngeal nerve is formed. Regeneration of the nerve’s functional abilities is a long process, lasting from 4 to 6 months, up to a year. A 35 year-old male was admitted to the Department of Otolaryngology at Warsaw Medical University in order to undergo surgical removal of reoccurrence of Schwannoma in left cerebellopontine angle by translabyrinthine approach. Post-operative period was complicated with vagal nerve paralysis. The patient reported hoarseness, dysphagia and choking. Physical examination revealed left vocal fold immobilization in abducted position, saliva in piriform fossa and left-sided soft palate paralysis yet the patient was discharged home. 4 weeks after the surgery, the patient was admitted to the hospital again due to developing aspiration pneumonia. Augmentation of the left vocal fold with calcium hydroxyapatite was performed 2 months later. After this intervention temporary vocal improvement and choking frequency reduction was observed. Finally, the patient underwent laryngeal reinnervation with formation of ansa cervicalis main branch to recurrent laryngeal nerve anastomosis. Left vocal fold regained its functional abilities and the quality of the voice improved. Laryngovideostroboscopy performed 6 months later revealed mobilization of left vocal fold sufficient for proper glottis closure. The voice measures normalized and the swallowing improved. Conclusions This case report and analyzed data confirm that laryngeal reinnervation surgery in unilateral vocal fold paralysis helps achieve satisfactory effects in voice function and life quality.

Phonomicrosurgery - a retrospective analysis of 400 cases

Introduction Voice disorders caused by pseudotumors of the vocal folds or paralysis of the vocal folds with incomplete glottis closure frequently require phonomicrosurgery. These interventions were analyzed with regard to quality of voice after surgery and safety of the intervention. Methods Retrospective analysis of 400 consecutive phonomicrosurgery interventions. The following parameters were collected: distribution of pathologies of the vocal folds, rating of the voice quality by both the surgeon (RBH-system) and patient and videolaryngstroboscopy six weeks after the intervention compared to the state prior to surgery, complications and results of histological examination. Results In our collective vocal fold polyps (36 %), cysts (12 %) and paralysis (10 %) dominated. After the intervention the quality of voice improved in 90 % of all cases. In 14 % voice therapy was needed postoperatively because of hyperfunction.After vocal fold augmentation one patient developed an edema of the larynx and another patient a temporary paralysis of the vocal fold of the opposite side. The histological examination showed as incidental findings a malignant osteoclastic giant cell tumor, a granular cell tumor and a carcinoma in situ of the vocal fold requiring further surgery and follow up. Discussion Phonomicrosurgery is a safe and effective therapy. The histological examination is also useful in patients with macroscopically non suspicious lesions to recognize rare or malignant tumor entities. Patient observation with early detection as well as therapy of complications like edema of the larynx or vocal fold paralysis is recommended.

Positron-emission tomography enhancement after vocal fold injection medialization.

The potential for the misinterpretation of positron-emission tomography (PET) scans in the context of a possible malignancy has been confirmed in a case report showing increased 18F-fluorodeoxyglucose (FDG) uptake after unilateral vocal fold augmentation medialization. We sought to expand these findings by investigating FDG uptake in a larger cohort of patients via a retrospective chart review. We examined the records of 15 adults-8 men and 7 women-who had undergone vocal fold augmentation for unilateral vocal fold paralysis and at least one subsequent PET scan. The differences in PET standard uptake value (SUV) between the injected and noninjected vocal folds were assessed via the Wilcoxon signed-rank test. A Spearman rank correlation coefficient was then used to estimate the relationship between differences in PET uptake and the length of time between the injection and the follow-up PET scan. The mean SUV of the injected vocal folds was 3.70, and the mean in the noninjected folds was 2.97. The difference did not achieve statistical significance (p = 0.34). In addition, the rank correlation coefficient with regard to the association between the difference in PET uptake and the duration between injection and PET was -0.24, suggesting an inverse relationship. However, the correlation coefficient did not differ significantly from zero (p = 0.34). We conclude that PET uptake after vocal fold augmentation medialization is variable and that it can increase substantially. This information should be considered in the context of the diagnostic accuracy of malignancy on PET.

Asystole During Direct Laryngoscopy for Vocal Fold Injection in a Healthy Patient

This study aims (1) to present a case of asystole during direct laryngoscopy in an otherwise healthy patient at an outpatient surgery center and (2) to review literature on cardiac complications, specifically asystole and bradycardia, during direct laryngoscopy. A 67-year-old woman with no prior cardiac history underwent induction with succinylcholine and remifentanil for direct laryngoscopy and vocal fold augmentation. During suspension laryngoscopy, the patient became asystolic, and advanced care life support measures were started. The patient regained a cardiac rhythm after chest compressions and epinephrine and was transferred to a tertiary care hospital for further treatment. She remained intubated overnight, requiring pressors, and regained normal cardiac function over the next few days. A structured literature review uncovered few reports of asystole during suspension laryngoscopy. Although bradycardia is common during suspension laryngoscopy, likely secondary to stimulation of afferent visceral sensory parasympathetic fibers of the vagus nerve, asystole is rare. Cardiac complications are possible in otolaryngologic surgery, especially with activation of the oculocardiac or trigeminocardiac reflexes. Asystole during direct laryngoscopy, although rare, is not always predictable from medicine or cardiac risk indices. Awareness, rapid recognition, and early implementation of advanced care life support are crucial to avoid further complications.

Human Adipose Tissue Derived Extracellular Matrix and Methylcellulose Hydrogels Augments and Regenerates the Paralyzed Vocal Fold.

Vocal fold paralysis results from various etiologies and can induce voice changes, swallowing complications, and issues with aspiration. Vocal fold paralysis is typically managed using injection laryngoplasty with fat or synthetic polymers. Injection with autologous fat has shown excellent biocompatibility. However, it has several disadvantages such as unpredictable resorption rate, morbidities associated with liposuction procedure which has to be done in operating room under general anesthesia. Human adipose-derived extracellular matrix (ECM) grafts have been reported to form new adipose tissue and have greater biostability than autologous fat graft. Here, we present an injectable hydrogel that is constructed from adipose tissue derived soluble extracellular matrix (sECM) and methylcellulose (MC) for use in vocal fold augmentation. Human sECM derived from adipose tissue was extracted using two major steps—ECM was isolated from human adipose tissue and was subsequently solubilized. Injectable sECM/MC hydrogels were prepared by blending of sECM and MC. Sustained vocal fold augmentation and symmetric vocal fold vibration were accomplished by the sECM/MC hydrogel in paralyzed vocal fold which were confirmed by laryngoscope, histology and a high-speed imaging system. There were increased number of collagen fibers and fatty granules at the injection site without significant inflammation or fibrosis. Overall, these results indicate that the sECM/MC hydrogel can enhance vocal function in paralyzed vocal folds without early resorption and has potential as a promising material for injection laryngoplasty for stable vocal fold augmentation which can overcome the shortcomings of autologous fat such as unpredictable duration and morbidity associated with the fat harvest.