Modified Laryngeal Forceps for Arytenoid Cartilage Dislocation Caused by Endotracheal Intubation: A Retrospective Case-Control Pilot Study.

Background: Arytenoid cartilage dislocation is considered as a rare laryngeal injury and closed reduction is commonly used as the first choice for the arytenoid dislocation. However, the tools of closed reduction vary, and there is no dedicated tool for closed reduction, and the treatment outcome varies from person to person. This study compared the treatment outcome of the modified laryngeal forceps and traditional laryngeal forceps. Material and Methods: This study conformed to the strengthening the reporting of observational studies in epidemiology guidelines regarding retrospective studies. From May 2021 to February 2023, the records of 28 patients with arytenoid cartilage dislocation caused by endotracheal intubation were reviewed. They were divided into the traditional group (n = 14) and the modified group (n = 14) by gender. Indirect or direct laryngoscopy, video stroboscopy, high-resolution computed tomography, and cricoarytenoid joint 3-dimensional reconstruction were used to evaluate arytenoid position and motion. Clinical characteristics, voice function, procedural skill, and treatment outcome for each case were recorded. Results: Each patient was diagnosed with arytenoid dislocation caused by endotracheal intubation. There was no significant difference in the treatment outcome between the traditional group and the modified group (P > .05). However, the median time interval between closed reduction and the return of normal voice in the traditional group was 31.08 ± 10.56 days, which was significantly longer than the median time of 17.92 ± 3.83 days in the modified group (P < .05). Conclusion: Closed reduction with the modified laryngeal forceps under local anesthesia is an effective and safe procedure. Compared with traditional laryngeal forceps, the modified laryngeal forceps can shorten the treatment duration.

Predictors of uvulopalatopharyngoplasty outcomes in patients with supine predominant positional obstructive sleep apnea: a prospective observational study.

BACKGROUND: It is uncertain which factors substantially influence outcomes after uvulopalatopharyngoplasty (UPPP) in patients with supine predominant obstructive sleep apnea (POSA). OBJECTIVE: To explore the predictors of UPPP outcomes in POSA patients. METHODS: A total of 108 patient(52 positional patients (POSA) and 56 nonpositional patients(NPP)), who underwent the revised uvulopalatopharyngoplasty (H-UPPP), were retrospectively studied. The pre-operative information of these patients, including polysomnography (PSG), and upper airway CT, were collected for analysis. RESULTS: No difference was found in surgical success rates between POSA and NPP undergoing H-UPPP. In POSA patients, there were statistically significant differences between responders and nonresponders in body mass index (BMI), preoperative supine AHI, time of SaO2 < 90% (TS90) (all p < .05), minimal anteroposterior airway (mAP) (p = .016), minimal lateral airway (mLAT) (p = .002), minimal cross-sectional airway area (mCSA) (p < .001) at the velopharynx. mLAT (p = .014) and mCSA (p = .002) at the glossopharynx. The independent associated factors for surgical success were lower BMI (p < .001), narrowerm LAT (p = .002) and mAP (p < .001) at velopharynx, and wider mCSA (p < .001) at glossopharynx in POSA. CONCLUSION: POSA patients with lower BMI, narrower mLAT and mAP at velopharynx, wider mCSA at glossopharynx were more likely to achieve a positive outcome with H-UPPP.

The integrity and barrier function of porcine vocal fold epithelium: its susceptibility to damage by deoxycholic acid compared with pepsin.

PURPOSE: In this study, we aim to systematically evaluate the damaging role of gastric (pepsin and acid) and duodenal ingredients (bile acids) on vocal fold epithelium in excised porcine larynges. METHODS: Fresh ex vivo porcine larynges were exposed to one of five experimental conditions for 1 h. These conditions will be referred to as alkaline deoxycholic acid, acidic pepsin, acid pH3 only, acid pH5 only, and control, respectively. A Franz diffusing cell was used to evaluate the barrier function of vocal fold epithelium by measuring the permeability to fluorescein isothiocyanate dextran of 4 kDa. Histological changes were observed using transmission electron microscopy. RESULTS: After immersing the fresh porcine larynges in the five solution groups, we found that the vocal fold epithelium in the deoxycholic acid group had more permeability to FD4 than the pepsin group (P < 0.001). Fragmentation and desquamation of dead cell layers were observed in both the pepsin and deoxycholic acid groups, but were more severe in the deoxycholic acid group than the pepsin group. The thickness of the dead epithelial cell layer gradually increased with increasing acid concentration (P < 0.05). Additionally, the thickness of the dead epithelial cell layer in the deoxycholic acid group was significantly higher than that in the pepsin group (P < 0.01). CONCLUSION: Deoxycholic acid in a weakly acidic condition is more likely than pepsin to induce apoptosis in ex vivo porcine vocal fold epithelium, destroy the link proteins between epithelial cells, and affect their integrity and barrier function.

The Therapeutic Effects of Straw Phonation on Vocal Fatigue.

OBJECTIVES: Straw phonation has been investigated for its vocal warm-up effects on healthy populations and therapeutic effects on voice patients. The purpose of this article was to determine whether it is beneficial for vocal fatigue. STUDY DESIGN: Prospective cohort study METHODS: Twenty-five healthy participants were recruited into 1-hour vocal loading tasks followed by 10-minute vocal rest or straw phonation on 2 different days. Various parameters including phonation threshold pressure (PTP), mean airflow, closed quotient (CQ), current speaking effort level (EFFT), and laryngeal discomfort (DISC) were acquired at baseline, after vocal load, and after the intervention. RESULTS: Increased PTP, EFFT, and DISC were observed after vocal load. Decreased PTP, EFFT, and DISC were then acquired after both vocal rest or straw phonation. More significant improvements were obtained in straw phonation when compared with vocal rest. Additionally, significantly increased mean flow and decreased CQ were obtained after straw phonation when compared to vocal rest. CONCLUSIONS: Straw phonation has the potential to adjust aerodynamics within the vocal tract leading to improved vocal efficiency, optimized vibration mode, and attenuated vocal fatigue. This study provided a promising treatment for vocal fatigue that could have wide clinical relevance to voice users with high voice demands. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:E674-E679, 2020.

Regularity of voice recovery and arytenoid motion after closed reduction in patients with arytenoid dislocation: a self-controlled clinical study.

Background: Closed reduction is an effective treatment for arytenoid dislocation. The treatment is usually given more than once to obtain normal voice. However, when to perform the next closed reduction remains controversial.Objective: This study aimed to observe the regularity of the voice recovery and the arytenoid motion in patients with arytenoid dislocation after closed reduction.Material and methods: Thirty-one patients were recruited from September 2017 to April 2019. Results of their clinical data were reviewed retrospectively.Results: Among the thirty-one patients, their VHI scores, F0, jitter%, shimmer%, glottal-to-noise excitation %(GNE), maximum phonation time (MPT) and GRBAS Scale (G, R, B, A) improved significantly (p < .05), but there was no statistically significant difference for GRBAS Scale (S) (p>.05). The duration between last closed reduction and the restoring normal voice ranged from 1-8 days, with a mean of 4.65 ± 0.57 days, at the same time the glottis was completely closed.Conclusions and significance: Closed reduction for patients with arytenoid dislocation is an effective procedure. A time window between 4.08th and 5.22th day (at a confidence level of 95%) after the last closed reduction was identified to be critical for voice recovery.

The Effects of Photobiomodulation on Vocal Fold Wound Healing: In Vivo and In Vitro Studies.

Background: Photobiomodulation (PBM) is increasingly used in dermatology and dentistry due to its benefit of promoting wound healing and relieving pain; however, there is no corresponding research report on the application of PBM to vocal fold wound healing. Objective: To assess the potential wound-healing effects of PBM on the vocal folds via in vivo and in vitro experiments. Materials and methods: In in vitro study, vocal fold fibroblasts (VFFs) were irradiated under a diode laser with wavelength of 635 nm at energy density of 8 J/cm2. The Cell Counting Kit-8 (CCK-8) assay was used to study the viability of VFFs, and the gene expressions of COL1A2, COL3A1, IL-6, HAS2, and COX-2 were investigated by real-time polymerase chain reaction (RT-PCR). In in vivo study, 15 rabbits were used. Lamina propria of the left vocal folds of 12 rabbits was unilaterally stripped, and 6 of them were treated with PBM. The remaining three rabbits served as normal controls. After 3 months, all animals were sacrificed to obtain histological results. We used laryngoscope to record images of the healing phase. Results: Irradiation with energy density of 8 J/cm2 resulted in a 2.8% increase in cell proliferation (p < 0.05). However, the difference between the experimental and the control group became larger after 48 and 72 h of subsequent irradiation. RT-PCR results showed that the expression of COL1A2, COL3A1, and HAS2 was higher, and the expression of IL-6 and COX-2 was lower. Histological examination showed that, compared with the injury group, hyaluronic acid (HA) increased significantly, collagen deposition decreased, and the configuration of collagen was more organized after PBM treatment. Conclusions: PBM can inhibit inflammatory reaction and promote the secretion of HA to decrease the deposition of collagen and regenerate vocal fold tissue without scar.

Wound-healing effects of 635-nm low-level laser therapy on primary human vocal fold epithelial cells: an in vitro study.

Low-level laser therapy (LLLT) has been promoted for its beneficial effects on tissue healing and pain relief for skin and oral applications. However, there is no corresponding literature reporting on vocal fold wound healing. Our purpose was to assess the potential wound-healing effects of LLLT on primary human vocal fold epithelial cells (VFECs). In this study, normal vocal fold tissue was obtained from a 58-year-old male patient who was diagnosed with postcricoid carcinoma without involvement of the vocal folds and underwent total laryngectomy. Primary VFECs were then cultured. Cells were irradiated at a wavelength of 635 nm with fluences of 1, 4, 8, 12, 16, and 20 J/cm2 (50 mW/cm2), which correspond to irradiation times of 20, 80, 160, 240, 320, and 400 s, respectively. Cell viability of VFECs in response to varying doses of LLLT was investigated by the Cell Counting Kit-8 (CCK-8) method. The most effective irradiation dose was selected to evaluate the cell migration capacity by using the scratch wound-healing assay. Real-time polymerase chain reaction (RT-PCR) was used to detect the gene expression of TGF-ß1, TGF-ß3, EGF, IL-6, and IL-10. Irradiation with doses of 8 J/cm2 resulted in 4% increases in cell proliferation differing significantly from the control group (p < 0.05). With subsequent doses at 48 and 72 h after irradiation, the differences between the experimental and the control groups became greater, up to 9.8% (p < 0.001) and 19.5% (p < 0.001), respectively. It also increased cell migration and the expression of some genes, such as EGF, TGF-ß1, TGF-ß3, and IL-10, involved in the tissue healing process. This study concludes that LLLT at the preset parameters was capable of stimulating the proliferation and migration of human vocal fold epithelial cells in culture as well as increase the expression of some genes involved in tissue healing process. Additionally, successive laser treatments at 24 h intervals have an additive beneficial effect on the healing of injured tissues.

The effects of cryotherapy on vocal fold healing in a rabbit model.

OBJECTIVES/HYPOTHESIS: Cryotherapy has been shown to be a scarless treatment modality for dermal lesions; however, there are limited data addressing the effect of cryotherapy on vocal fold tissue. The aim of this study was to clarify the effectiveness of cryotherapy for prevention of postsurgical vocal fold scarring. STUDY DESIGN: Prospective animal study in rabbits. METHODS: The lamina propria of 20 rabbit vocal folds was bilaterally stripped, followed by randomized unilateral cryotherapy. Five larynges were harvested for real-time polymerase chain reaction (RT-PCR) analysis at 1 day, 3 days, and 7 days postinjury. The remaining five were harvested for histologic analysis at 3 months. Images of the healing phase were recorded by laryngoscopy. Analyses of RT-PCR for cyclooxygenase (COX)-2, interleukin (IL)-6, collagen I, collagen III, matrix metallopeptidase 1 (MMP1), transforming growth factor ß (TGFß1), α smooth muscle actin (α-SMA), and hyaluronan synthase 1 (HAS1) were completed. Histological samples were completed for collagen and hyaluronic acid analysis. RESULTS: RT-PCR results revealed that higher expressions of HAS1 and MMP1 and lower expressions of COX-2, IL-6, collagen I, collagen III, TGFß1, and α-SMA were observed, and histological examination showed significantly increased hyaluronic acid, decreased deposition, and more organized configuration of collagen in injury with the cryotherapy cohort compared with the injury cohort. CONCLUSIONS: Cryotherapy can inhibit the inflammatory reaction and simulate a fetal healing environment in extracellular matrix synthesis to regenerate vocal fold tissue with less fibrosis. Histological results showed that cryotherapy achieves a mature healing result with less scar, which tends to return to normal. In summary, the findings of this study suggest that administration of cryotherapy at the time of injury has the potential to minimize vocal fold scarring. LEVEL OF EVIDENCE: NA Laryngoscope, 129:E151-E157, 2019.

Establishment of a novel and effective reflux laryngitis model in rabbits: a preliminary study.

PURPOSE: To establish a novel and effective reflux model with a modified nasogastric aspiration tube and to investigate the association between different types of nasogastric aspiration tubes and reflux laryngitis, we conducted this study. METHODS: Thirty-eight healthy New Zealand albino rabbits (2.5-3.5 kg) were divided into three groups: control (CTR, n = 6)-non-intubated; normal nasogastric intubation (NNI, n = 16)-intubated with 4#, 6#, 8#, and 10# normal nasogastric aspiration tubes; and modified nasogastric intubation (MNI, n = 16)-intubated with 4#, 6#, 8#, and 10# modified nasogastric aspiration tubes. The laryngoscopy, body weight, and pH values at the esophageal entrance were recorded before and 1, 2, and 4 weeks after intubation. After the final laryngoscopy, the animals in groups with a pH below 4 were sacrificed to obtain histological and gene expression analysis results. RESULTS: The reflux finding score (RFS) after 4 weeks showed that there was a statistically significant difference in the 8# NNI group (7 ± 0.816, P < 0.001), the 8# MNI group (11.5 ± 2.517, P < 0.001) and the 10# MNI (12.75 ± 1.893, P < 0.001) group compared with the control group (1.83 ± 1.602). The pH values of these three groups were lower than 4. However, the weight loss of the rabbits in the 10# NNI and 10# MNI groups was more obvious. Submucous gland hyperplasia and inflammation were significantly increased in the 8# NNI group, 8# MNI group and the 10# MNI group, but in the level of some pro-inflammatory cytokines and COX-2, the MNI group was significantly higher than the NNI group (8# NNI × 8# MNI, P < 0.01; 8# MNI × 10# MNI, P < 0.01). CONCLUSION: This study showed that 8# modified nasogastric intubation (MNI) produces effective reflux laryngitis in the rabbits.

BMI May Be the Risk Factor for Arytenoid Dislocation Caused by Endotracheal Intubation: A Retrospective Case-Control Study.

OBJECTIVE: This study aimed to investigate the risk factors for postoperative arytenoid dislocation caused by endotracheal intubation. METHODS: From September 2014 to September 2016, the records of 28 patients with a history of postoperative arytenoid dislocation were reviewed. Patients matched in type of anesthesia and surgery were chosen as the control (n = 56). Recorded data for all patients were demographics, smoking status, alcoholic status, operation time, and anesthesia procedures. For arytenoid dislocation cases, we further analyzed the incidences of the left and right arytenoid dislocations. Categorical variables were presented as frequencies and percentages, and were compared using the chi-square test. Continuous variables were expressed as means ± standard deviation and compared using the Student unpaired t test. To determine the predictors of arytenoid dislocation, a logistic regression model was used for multivariate analysis. Statistical significance was indicated by P < 0.05. RESULTS: Twenty-eight patients demonstrating postoperative arytenoid dislocation (10 women and 18 men) were included, with a mean age of 55 ± 12 years. Sixteen patients (57.14%) had left arytenoid dislocation and 12 (42.86%) had right arytenoid dislocation. Univariate analysis indicated that body mass index (BMI) was associated with arytenoid dislocation (P < 0.01), and logistic regression analysis showed that BMI (P = 0.025) was an independent risk factor for postoperative arytenoid dislocation. CONCLUSIONS: BMI might be the independent risk factor for postoperative arytenoid dislocation.

The appropriate time for closed reduction using local anesthesia in arytenoid dislocation caused by intubation: a clinical research.

CONCLUSION: Closed reduction is effective and safe for the treatment of arytenoid dislocation, and the selection of an appropriate time window to perform closed reduction is crucial in achieving relatively stable treatment outcomes and short treatment duration. OBJECTIVE: The aim of this study was to investigate whether there is an appropriate time window to perform closed reduction for unilateral arytenoid dislocation caused by intubation. METHODS: A retrospective chart review was carried out for the cases collected from September 2014 to May 2016 at Second Affiliated Hospital of Zhejiang University, China. RESULTS: Thirty-five patients with arytenoid dislocation were identified. Endotracheal intubation was the cause for 33 of the patients and gastric tube caused arytenoid dislocation in two patients. The patients were treated by closed reduction, and no major complications resulting from surgical intervention were observed. All patients regained normal voice and vocal fold movement after the surgery, except one patient who recovered spontaneously. As one of the most significant findings in the current study, we observed the relatively stable treatment outcomes and shortened recovery duration were obtained in the patients treated during a period between the 13th day and 26th day after arytenoid dislocation.