Efficacy of Botulinum Toxin Injection for Airway Management in Patients with Transient Bilateral Vocal Fold Paresis Following Thyroidectomy: A Prospective Study.

OBJECTIVES: This prospective study evaluated the effectiveness and safety of botulinum toxin injection for airway management in patients with transient bilateral vocal fold paresis (BVFP) after thyroidectomy. STUDY DESIGN: Prospective clinical study. METHODS: A prospective study was conducted at Soonchunhyang University, Bucheon, Korea, between March 2005 and February 2023. This study enrolled 12 patients with BVFP after thyroidectomy who received botulinum toxin injections into the thyroarytenoid muscles. Vocal fold mobility and airway distress were assessed using a flexible laryngoscope before and after injection. RESULTS: Of the 3018 thyroidectomy patients, 12 (0.39%) developed transient BVFP after surgery. Under the guidance of laryngeal electromyography, 3.6 ± 0.6 IU botulinum toxin was administered into the bilateral thyroarytenoid muscles. Notably, nine patients (75%) received a single injection, whereas three (25%) received an additional injection after 7days. The mean time for vocal fold movement recovery was 33.2 ± 17.2days after injection; conventional destructive procedures for BVFP were avoided in 10 of the 12 patients (83.3%). CONCLUSIONS: Botulinum toxin injection offers a novel approach to airway management in patients with transient BVFP after thyroidectomy. LEVEL OF EVIDENCE: Level 4.

Treatment efficacy of 532-nm diode laser glottoplasty in patients with sulcus vocalis: a prospective study.

PURPOSE: This study prospectively assessed the efficacy and safety of 532-nm diode laser glottoplasty in patients with sulcus vocalis. METHODS: A prospective human trial was performed from August 2016 to September 2021. 532-nm diode laser glottoplasty was performed in 30 consecutive patients with sulcus vocalis who suffered from voice problems. Patients underwent acoustic aerodynamic, perceptual, stroboscopic, and Voice Handicap Index-10 (VHI-10) evaluations before and 1, 6, and 12 months after laser glottoplasty. RESULTS: Most subjective parameters showed significant improvement (P < 0.05) at 6 months after laser glottoplasty and remained stable at 12 months. Most objective parameters showed significant improvement (P < 0.05) at 12 months after laser glottoplasty. Complications during follow-up included mild vocal fold vibration reduction in 3.3% of patients (1/30) and persistent vocal fold edema in 3.3% of patients (1/30). CONCLUSIONS: Statistically significant voice improvement at 12 months after 532-nm diode laser glottoplasty was achieved without serious complications.

Effect of statin use on head and neck cancer prognosis in a multicenter study using a Common Data Model.

Few studies have found an association between statin use and head and neck cancer (HNC) outcomes. We examined the effect of statin use on HNC recurrence using the converted Observational Medical Outcome Partnership (OMOP) Common Data Model (CDM) in seven hospitals between 1986 and 2022. Among the 9,473,551 eligible patients, we identified 4669 patients with HNC, of whom 398 were included in the target cohort, and 4271 were included in the control cohort after propensity score matching. A Cox proportional regression model was used. Of the 4669 patients included, 398 (8.52%) previously received statin prescriptions. Statin use was associated with a reduced rate of 3- and 5-year HNC recurrence compared to propensity score-matched controls (risk ratio [RR], 0.79; 95% confidence interval [CI], 0.61-1.03; and RR 0.89; 95% CI 0.70-1.12, respectively). Nevertheless, the association between statin use and HNC recurrence was not statistically significant. A meta-analysis of recurrence based on subgroups, including age subgroups, showed similar trends. The results of this propensity-matched cohort study may not provide a statistically significant association between statin use and a lower risk of HNC recurrence. Further retrospective studies using nationwide claims data and prospective studies are warranted.

A Novel Intervention That Prevents Vocal Fold Scarring.

OBJECTIVES: We evaluated the preventive efficacy of stromal vascular fraction (SVF) for vocal fold scar in a rabbit model. STUDY DESIGN: Animal model. METHODS: The study included 40 male New Zealand white rabbits: 20 received vocal fold scar surgery served as normal controls (control group). The other 20 received the same vocal fold scar surgery with SVF injection (SVF group) Histological and high-speed video analyses of vocal fold vibration were performed 4 weeks after scar surgery and SVF injection. The maximum amplitude of vocal fold vibration was used to assess vocal fold vibration. A real-time PCR study was also performed to evaluate the scar regeneration and remodeling including TGF-ß1, IL-6, procollagen-1, MMP-2, 9, and HAS-2, 3. RESULTS: Vocal fold vibration analyses indicated that the maximum amplitude differences in the vibration of the SVF group were significantly higher than the control group. The histological findings showed that the collagen density ratio were significantly lower in the SVF group compared to the control group. Real-time Polymerase Chain Reaction (PCR) study showed significant increases of MMP-2, 9 and HAS-2, 3, and a decrease of TGF-ß1, IL-6, procollagen-1 in the SVF group compared to the control group. CONCLUSIONS: Based on the vocal fold vibration study, histological findings, and real-time PCR study, SVF injection showed preventive activity and improvement of vocal fold vibration for vocal fold scar in a rabbit model.

Regenerative Effect of a 532-nm Diode Laser on Vocal Fold Scar in a Rabbit Model.

OBJECTIVES: We evaluated the regenerative effect of a 532-nm diode laser in a rabbit model of vocal fold scarring. METHODS: This study included 40 male New Zealand white rabbits: 20 underwent vocal fold scar surgery only (control group) and 20 underwent 532-nm diode laser glottoplasty 1 month after vocal fold scar surgery (glottoplasty group). Histological and high-speed video analyses of vocal fold vibration were performed 1 month after vocal fold scar surgery and laser glottoplasty. The maximum amplitude of vocal fold vibration and dynamic glottal gap was measured. Real-time polymerase chain reaction (PCR) was also performed to evaluate scar regeneration and wound remodeling. Transforming growth factor (TGF)-ß1, interleukin (IL)-6, procollagen-1, matrix metalloproteinase (MMP)-2, MMP-9, hyaluronan synthase (HAS)-2, and HAS-3 levels were measured. RESULTS: The maximum difference in amplitude of vocal fold vibration and the dynamic glottal gap was significantly greater in the glottoplasty than in the control group. Real-time PCR revealed significantly higher MMP-2, MMP-9, HAS-2, and HAS-3 levels, and lower TGF-ß1, IL-6, and procollagen-1 level, in the glottoplasty than control group. The histological findings showed that the lamina propria (LP) ratio (LP pixels/total vocal fold pixels) was not significantly different between the two groups. CONCLUSIONS: Based on the vocal fold vibration and real-time PCR results, the 532-nm diode laser improved vocal fold vibration in a rabbit model of vocal fold scarring.

Comparison between Real-Time Ultrasound-guided Percutaneous Dilatational Tracheostomy and Surgical Tracheostomy in critically ill Patients: A Randomized Controlled Trial.

OBJECTIVES: Tracheostomy is an important procedure for critically ill patients in the intensive care unit (ICU), and percutaneous dilatational tracheostomy (PDT) has gained popularity due to its safety and effectiveness. However, there are limited data comparing ultrasound-guided PDT (US-PDT) with surgical tracheostomy (ST). In our previous study, we reported that US-PDT had similar safety and effectiveness to ST, with a shorter procedure time. However, the study design was retrospective, and the sample size was small. Therefore, we conducted a randomized controlled trial to demonstrate the safety and efficacy of US-PDT compared to ST. METHODS: A total of 70 patients who underwent either US-PDT (n=35) or ST (n=35) were enrolled in the study between October 20, 2020 and July 26, 2022. The patients were randomly assigned to their respective procedures. The data collected included patient clinical characteristics, procedure time and details, complications, duration of ICU stay, time taken for weaning from mechanical ventilation, and hospital mortality. RESULTS: The procedure time of US-PDT was shorter than that of ST (4.0±2.2 minutes vs. 10.1±4.6 minutes). The incision length of US-PDT was also shorter than that of ST (1.5±0.5 cm vs. 1.8±0.4 cm). There were no statistically significant differences in demographics, procedure details, complications, length of ICU stay, ventilator weaning time, and hospital mortality. CONCLUSION: US-PDT has a similar complication rate and shorter procedure time compared with ST. It can be safely and effectively performed in critically ill patients and can serve as a potential alternative to ST.

Self-organized insulin-producing ß-cells differentiated from human omentum-derived stem cells and their in vivo therapeutic potential.

BACKGROUND: Human omentum-derived mesenchymal stem cells (hO-MSCs) possess great potential to differentiate into multiple lineages and have self-renewal capacity, allowing them to be utilized as patient-specific cell-based therapeutics. Although the use of various stem cell-derived ß-cells has been proposed as a novel approach for treating diabetes mellitus, developing an efficient method to establish highly functional ß-cells remains challenging. METHODS: We aimed to develop a novel cell culture platform that utilizes a fibroblast growth factor 2 (FGF2)-immobilized matrix to regulate the adhesion and differentiation of hO-MSCs into insulin-producing ß-cells via cell-matrix/cell-cell interactions. In our study, we evaluated the in vitro differentiation potential of hO-MSCs cultured on an FGF2-immobilized matrix and a round-bottom plate (RBP). Further, the in vivo therapeutic efficacy of the ß-cells transplanted into kidney capsules was evaluated using animal models with streptozotocin (STZ)-induced diabetes. RESULTS: Our findings demonstrated that cells cultured on an FGF2-immobilized matrix could self-organize into insulin-producing ß-cell progenitors, as evident from the upregulation of pancreatic ß-cell-specific markers (PDX-1, Insulin, and Glut-2). Moreover, we observed significant upregulation of heparan sulfate proteoglycan, gap junction proteins (Cx36 and Cx43), and cell adhesion molecules (E-cadherin and Ncam1) in cells cultured on the FGF2-immobilized matrix. In addition, in vivo transplantation of differentiated ß-cells into animal models of STZ-induced diabetes revealed their survival and engraftment as well as glucose-sensitive production of insulin within the host microenvironment, at over 4 weeks after transplantation. CONCLUSIONS: Our findings suggest that the FGF2-immobilized matrix can support initial cell adhesion, maturation, and glucose-stimulated insulin secretion within the host microenvironment. Such a cell culture platform can offer novel strategies to obtain functional pancreatic ß-cells from patient-specific cell sources, ultimately enabling better treatment for diabetes mellitus.

Guideline for the Surgical Management of Locally Invasive Differentiated Thyroid Cancer From the Korean Society of Head and Neck Surgery.

The aim of this study was to develop evidence-based recommendations for determining the surgical extent in patients with locally invasive differentiated thyroid cancer (DTC). Locally invasive DTC with gross extrathyroidal extension invading surrounding anatomical structures may lead to several functional deficits and poor oncological outcomes. At present, the optimal extent of surgery in locally invasive DTC remains a matter of debate, and there are no adequate guidelines. On October 8, 2021, four experts searched the PubMed, Embase, and Cochrane Library databases; the identified papers were reviewed by 39 experts in thyroid and head and neck surgery. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess the quality of evidence, and to develop and report recommendations. The strength of a recommendation reflects the confidence of a guideline panel that the desirable effects of an intervention outweigh any undesirable effects, across all patients for whom the recommendation is applicable. After completing the draft guidelines, Delphi questionnaires were completed by members of the Korean Society of Head and Neck Surgery. Twenty-seven evidence-based recommendations were made for several factors, including the preoperative workup; surgical extent of thyroidectomy; surgery for cancer invading the strap muscles, recurrent laryngeal nerve, laryngeal framework, trachea, or esophagus; and surgery for patients with central and lateral cervical lymph node involvement. Evidence-based guidelines were devised to help clinicians make safer and more efficient clinical decisions for the optimal surgical treatment of patients with locally invasive DTC.

A case of initially metastasizing pleomorphic adenoma of parotid gland.

Metastasis of pleomorphic adenoma (PA) is rare and usually presented as a locoregional recurrence developed many years after excision of the primary tumor although the PA is the most common neoplasm in the parotid gland. We described a case of a 48-year-old male with a parotid tumor with multiple enlarged ipsilateral lymph nodes which suggested a malignancy. The tumors had been neither evaluated nor excised and preoperative evaluation revealed benign PA in both lesions. After the complete surgical excision, the final pathology was notable for benign PA with metastasis to regional lymph nodes. At 1 year follow up he was clinically and radiographically free of disease. This implies that pleomorphic adenoma can occur as initially metastasis to regional lymph node even though benign neoplasm.

Comparison Between Real-Time Ultrasound-Guided Percutaneous Tracheostomy and Surgical Tracheostomy in Critically Ill Patients.

Background: Ultrasound-guided percutaneous dilatational tracheostomy (US-PDT) has been adapted for use in intensive care units (ICU). US-PDT is comparable to bronchoscopy-assisted tracheostomy. However, compared to surgical tracheostomy (ST), its safety and effectiveness have not been well studied. Objectives: To determine the efficacy and safety of US-PDT compared to ST. Materials and Methods: A total of 90 patients who underwent US-PDT (n = 36) or ST (n = 54) between July 2019 and September 2020 were enrolled. US-PDT was performed in the ICU without a surgical assistant or bronchoscope. Data were collected retrospectively and analyzed regarding clinical characteristics, procedure times and details, complications, and mortality rate. Results: The success rate of US-PDT was 97.4% and the procedure time was shorter than ST (5.2 ± 3.1 vs. 10.5 ± 5.0 min). There were no significant differences in clinical characteristics and procedure details. There was no procedure-related mortality in either of the groups. Conclusions: US-PDT is time-efficient and as safe as ST. Based on our results, US-PDT may be considered a potential alternative to ST in high-risk patients and in those who cannot be transported.

A Rare Case of Well-Differentiated Parapharyngeal Liposarcoma.

Parapharyngeal liposarcoma is a rare malignant tumor, the pathogenesis of which is uncertain. Parapharyngeal liposarcoma often causes nonspecific clinical features, including dysphagia, globus sensation, and/or respiratory disturbances. The parapharyngeal space is a rare location for head and neck liposarcoma, and these lesions may therefore be confused with a variety of other tumors that can originate in this area. Here, we report a case of liposarcoma originating from the prestyloid parapharyngeal space and discuss the possible differential diagnosis on radiographic findings.

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

Voice change is a common complaint after thyroid surgery and has a significant impact on quality of life. The Korean Society of Laryngology, Phoniatrics and Logopedics assembled a task force to establish guideline recommendations on education, care, and management related to thyroid surgery. The guideline recommendations encompass preoperative voice education, management of anticipated voice change during surgery, and comprehensive voice care after thyroid surgery, and include in-depth information and up-to-date knowledge based on validated literature. The committee constructed 14 key questions (KQs) in three categories-preoperative (KQ 1-2), 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. A detailed evidence profile is presented for each recommendation. The level of evidence for each recommendation was classified as high-quality, moderate-quality, or low-quality. The strength of each recommendation was designated as strong or weak considering the level of evidence supporting the recommendation. 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.

Regenerative efficacy of fibroblast growth factor for the treatment of aged vocal fold: From animal model to clinical application.

OBJECTIVES: We assessed fibroblast growth factor (FGF) regenerative efficacy in an aged vocal fold rat model and confirmed it in a prospective clinical trial. DESIGN, SETTING, AND PARTICIPANTS: For animal experiments, 48 Sprague-Dawley rats were divided into two groups: 24 six-month-olds (young group) and 24 twenty-four-month-olds (old group). FGF was injected once a week thrice into the left vocal fold of the old group, dividing them into two sub-groups (injected [left] and uninjected [right]). Additionally, we conducted a prospective clinical trial for 38 patients with aged atrophic vocal fold. MAIN OUTCOME MEASURES: A month post-injection, excised larynx from the three groups was subjected to comparative histopathological (ratio of relative lamina propria to total vocal fold) and mRNA expression analysis (of procollagen I, hyaluronic acid synthase (HAS)-2 and matrix metalloproteinase (MMP)-2) by real-time PCR. We performed perceptual, stroboscopic, acoustic aerodynamic test and Voice Handicap Index survey prior to and 1, 6 and 12 months after FGF injection. RESULTS: In rats, the relative lamina propria ratio increased after FGF injection. Procollagen I mRNA level decreased, whereas that of HAS-2 and MMP-2 increased significantly in the injected compared to the uninjected old group. Enrolled patients showed improved subjective and objective voice parameters after FGF injection, and these were maintained for a year. Potential side effects were not observed. CONCLUSIONS: Animal experiments and prospective clinical trial suggest that FGF injection to vocal fold can significantly improve voice quality until one year, without complications, and is effective for aged atrophic vocal fold treatment.

A long-term comparative prospective study between reinnervation and injection laryngoplasty.

OBJECTIVES: This study compared and assessed long-term voice outcomes when thyroidectomy-related unilateral vocal fold paralysis (VFP) was managed using injection laryngoplasty (IL) and recurrent laryngeal nerve reinnervation (RLNR). STUDY DESIGN: Prospective clinical study. METHODS: A prospective clinical trial was performed from March 2005 to January 2016 at Soonchunhyang University Bucheon Hospital (Bucheon, South Korea). Nineteen patients who underwent ansa cervicalis to RLNR or direct reinnervation, and 43 patients who underwent IL to treat thyroidectomy-related unilateral VFP, were enrolled. RESULTS: All voice parameters exhibited statistically significant improvement 12 months post-IL, which persisted for 24 and 36 months (P < 0.05). However, at 36 months post-IL, some voice parameters had deteriorated relative to the values at 24 months post-IL. After RLNR, all voice parameters exhibited statistically significant improvement after 12 months, and the improvements remained stable until 36 months postsurgery without deterioration of voice parameters (P < 0.05). At 36 months, RLNR provided better voice results than IL (P < 0.05). CONCLUSION: Both RLNR and IL yielded statistically significant voice improvements at 36 months postoperatively. However, after 36 months, RLNR provided better results than IL. LEVEL OF EVIDENCE: 3. Laryngoscope, 1893-1897, 2018.

A clinical prediction score to determine surgical drainage of deep neck infection: A retrospective case-control study.

BACKGROUND: The objective of this retrospective study was to identify predictors of an abscess guaranteed to be surgically drained successfully in patients with deep neck infection (DNI). MATERIALS AND METHODS: We divided 97 consecutive patients with DNI into a drained group and a non-drained group. We then developed a clinical prediction score and validated it in 32 further patients. RESULTS: Significant predictors of successful surgical drainage (i.e., positive for pus) were rim enhancement on computed tomography, C-reactive protein, erythrocyte sedimentation rate, and the neutrophil to lymphocyte ratio. The estimated cut-off values (excluding rim enhancement, which is a yes/no parameter) were 41.25, 56.5, and 8.02, respectively, and the clinical prediction score for each of the four other factors was determined to be 2, 2, 3, and 3 points, respectively. The cut-off score for the sum of these points was 6.5 and the scoring system had an accuracy of 87.5% in the validation group. CONCLUSION: Our clinical prediction scoring system can predict whether drainage is successful in patients with DNI.

Korean survey data reveals an association of chronic laryngitis with tinnitus in men.

The association between chronic laryngitis and tinnitus is not a well-studied topic, unlike the association of these two conditions with many other disorders. Cross-sectional data of 11,347 adults (males: 4,934; females: 6,413), who completed the Korea National Health and Nutrition Examination Survey (KNHANES) from 2010 to 2012 were used to investigate this association. Lifestyle patterns, including smoking and alcohol habits, regular exercise, physical and mental health status, socioeconomic status, nutritional status, and other chronic diseases, were analyzed. Chronic laryngitis and tinnitus were diagnosed by field survey teams, which included otolaryngologists, who conducted chronic disease surveillance using a health status interview, a nutritional status questionnaire, and a physical examination. Chronic laryngitis was significantly associated with age, education beyond high school, depressed mood, voice change, metabolic syndrome, and tinnitus in men. In women, chronic laryngitis was associated with body mass index and diabetes mellitus. Chronic laryngitis in men was significantly associated with tinnitus (odds ratio 1.671, [95% confidence interval: 1.167-2.393]) after adjusting for age, body mass index, smoking status, alcohol intake, regular exercise, metabolic syndrome, education beyond high school, and depressed mood. Additionally, the prevalence of chronic laryngitis increased with increasing severity of tinnitus in men alone (P = 0.002). The study revealed a significant association between chronic laryngitis and tinnitus.

The Efficacy of Fibroblast Growth Factor for the Treatment of Chronic Vocal Fold Scarring: From Animal Model to Clinical Application.

OBJECTIVES: This study assessed the regenerative efficacy of basic fibroblast growth factor (FGF) in a rabbit model of chronic vocal fold scarring and then confirmed its utility and safety in a prospective trial of patients with this condition. METHODS: FGF was injected three times, at 1-week intervals, into a chronic vocal fold scar created in a rabbit model. After 1 month, mRNA level of procollagen I, hyaluronic acid synthetase 2 (HAS 2), and matrix metalloproteinase 2 (MMP 2) were analyzed by real-time polymerase chain reaction. The relative densities of hyaluronic acid (HA) and collagen were examined 3 months post-injection. From April 2012 to September 2014, a prospective clinical trial was conducted at a tertiary hospital in Korea. FGF was injected into the mild vocal fold scar of 17 consecutive patients with a small glottic gap. The patients underwent perceptual, stroboscopic, acoustic aerodynamic test, and Voice Handicap Index (VHI) survey prior to and 3, 6, and 12 months after FGF injection. RESULTS: FGF injection of the vocal fold scar decreased the density of collagen and increased mRNA level of HAS 2 and MMP 2 expression significantly compared to the control group injected with phosphate buffered solution in a rabbit model (P<0.05). In the clinical trial, significant improvements in the majority of the subjective and objective voice parameters were registered 3 months after FGF injection and were maintained at 12 months. Complications associated with the FGF injections, such as granuloma, were not observed during the follow-up period. CONCLUSION: Based on the animal model and the prospective clinical trial, vocal fold injections of FGF in patients with mild chronic vocal fold scarring can significantly improve voice quality for as long as 1 year and without side effects. Our results recommend the use of FGF vocal fold injection as an alternative treatment modality for mild chronic vocal fold scarring.

Epidemiological association of olfactory dysfunction with hearing loss and dysphonia in the Korean population: A cross-sectional study.

The aim of the study is to investigate the association between olfactory dysfunction (OD), hearing loss, and dysphonia.The cross-sectional data for 17,984 adults who completed the Korea National Health and Nutrition Examination Surveys (2010-12) were analyzed. OD, hearing loss, and dysphonia were assessed using self-reporting questionnaires. The association of OD with hearing loss and dysphonia was evaluated.Hearing loss and dysphonia were significantly more prevalent in patients with OD than in those without OD (hearing loss, 28.1% vs 11.3%; dysphonia, 11.1% vs 5.9%; both P < .0001). After adjusting for confounders, including mental stress and metabolic syndrome, the risk of OD was significantly associated with hearing loss and dysphonia, and was greater in those with combined hearing loss and dysphonia than in both patients without these dysfunctions and in those with a single dysfunction (odds ratio 3.115, 95% confidence interval 1.973-4.917).OD was significantly associated with hearing loss and dysphonia.