Shun-ichi Chitose

Analysis of voice function following autologous fat injection for vocal fold paralysis

OBJECTIVE: This study demonstrates that intravocal fold injection of autologous fat obtained by liposuction technique is simple, and the functional results durable for patients with unilateral vocal fold paralysis due to injury to the recurrent laryngeal nerve. STUDY DESIGN: 41 patients with unilateral paralysis of the vocal fold due to injury to the recurrent laryngeal nerve received intravocal fold injection of autologous fat. Autologous fat, harvested from the lower abdomen by liposuction technique, was filtered out and injected through a needle into the vocal fold by using endolaryngeal microsurgery. Clinical follow-up after the injection was carried out from 1 month to 2 years. RESULTS: Voice function dramatically improved compared with the parameters examined before the operation. Vocal function continued to improve as time passed during the second year after injection. CONCLUSIONS: Intravocal fold injection of autologous fat obtained by liposuction technique is simple, and the functional results durable for patients with unilateral vocal fold paralysis due to injury to the recurrent laryngeal nerve. SIGNIFICANCE: The effectiveness continued for more than 2 years in most patients.

Origin of Vocal Fold Stellate Cells in the Human Macula Flava

Objectives: There is growing evidence that vocal fold stellate cells (VFSCs) in the human maculae flavae are tissue stem cells of the human vocal fold and that the maculae flavae are a stem cell niche. The origin of the cells in the human maculae flavae (CHMF) and the relationship with bone marrow–derived cells were investigated. Methods: Five human adult vocal fold mucosae were investigated. The CHMF were subcultured and morphological features were assessed. Immunoreactivity to antibodies directed to cytokeratin, desmin, GFAP, vimentin, CD34, CD45, and collagen type I was investigated. Results: Cultured CHMF formed a colony-forming unit, indicating they are mesenchymal stem cells or stromal stem cells in the bone marrow. The CHMF expressed hematopoietic markers (CD34, CD45) and collagen type I, which are the major makers for bone marrow–derived circulating fibrocytes. The cultured CHMF expressed epithelium-associated, muscle-associated, neural-associated, and mesenchymal cell–associated proteins, indicating the CHMF are undifferentiated and express proteins of all 3 germ layers. Conclusions: The CHMF are undifferentiated cells derived from the differentiation of bone marrow cells. The results of this study are consistent with the hypothesis that the VFSCs are tissue stem cells or progenitor cells of the human vocal fold mucosa.

Long-Term Postoperative Vocal Function after Thyroplasty Type I and Fat Injection Laryngoplasty

Objectives: We evaluated the differences in the long-term functional results of medialization thyroplasty type I (MT) and autologous fat injection laryngoplasty (FIL) in patients with unilateral vocal fold paralysis. Methods: Forty-one patients underwent MT, and 73 patients underwent FIL. The voice functions before and after both surgeries were examined by aerodynamic, pitch and intensity, and acoustic analyses. The postoperative voice examinations were performed 12 months (median) after the MT, and 4 years (median) after the FIL. The differences between the preoperative and postoperative parameters were examined with a paired t-test for each group separately. For each variable, a comparison of the effects of surgery was conducted with an analysis of covariance model, with the change between the preoperative and postoperative values as the dependent variable and the preoperative value as the covariate. Results: In both groups, all parameters significantly improved after surgery. In particular, there was a significant difference for the postoperative acoustic analyses. However, the aerodynamic analysis after FIL improved more significantly in comparison to that after MT because of the respiratory handicap. Conclusions: We found that MT and FIL provided almost the same effectiveness, and that both surgeries were reliable in improving the vocal function in patients with vocal fold paralysis.

Deglutition and respiratory patterns during sleep in younger adults

Abstract Conclusion: Deglutition was infrequent and displayed unique patterns during sleep in healthy younger adults. Objectives: The deglutition, electroencephalographic arousal, and respiratory phase patterns during sleep in younger adults were investigated. Methods: Ten younger adults were examined via time-matched recordings of polysomnography and surface electromyography. Results: During sleep, swallowing was infrequent and absent for long periods. The mean number of swallows per hour during the total sleep time was 2.4 ± 1.0. The mean longest deglutition-free period was 68.8 ± 24.8 min. Most deglutition occurred in association with spontaneous electroencephalographic arousal. Deglutition was related to the sleep stage. The mean number of swallows per hour was 11.2 ± 8.1 during stage 1 sleep, 1.9 ± 1.0 during stage 2 sleep, 0.5 ± 1.5 during stage 3 sleep, and 0.2 ± 0.5 during stage 4 sleep. The deeper the sleep stage, the lower the mean deglutition frequency. The mean number of swallows per hour was 1.9 ± 1.7 during rapid eye movement sleep. The deeper the sleep stage, the lower the mean arousal frequency and the lower the mean ratio of arousal with deglutition to arousal. Approximately 60% of swallows were followed by arrested breathing and approximately 25% by expiration.

Efficacy of Additional Injection Laryngoplasty after Framework Surgery

Objectives: The purpose of this study was to clarify the efficacy of additional injection laryngoplasty (AIL) after framework surgery (FS), while also trying to identify which patients or procedures were more likely to require AIL to obtain optimal results and to clarify why. Methods: Fifty-two patients with unilateral vocal fold paralysis underwent FS (thyroplasty [TP], 23; arytenoid adduction [AA], 18; and AA with TP, 11). The numbers of patients who required AIL were calculated for each type of FS. The voice function after AIL was investigated. Thereafter, the width and the bowing ratios on phonation were measured in patients who underwent AA. Results: The patients who underwent AA required AIL more frequently than did patients who underwent TP. Use of AIL provided better voice function for all patients. The width ratio after AA decreased in all cases, but the bowing ratio increased after AA in 44% of cases. Conclusions: These results indicate that AIL is an effective treatment for patients who still have a glottal gap after undergoing FS. In particular, patients who had AA frequently required AIL, in comparison to patients who had TP, because of the high frequency of an increased bowing ratio after AA.

A new paradigm of endoscopic cricopharyngeal myotomy with CO2 laser

INTRODUCTION Over the past decade, endoscopic cricopharyngeal myotomy (ECPM) using a laser has been introduced as an alternative surgical procedure to transcervical cricopharyngeal myotomy (TCPM). Although a wide resection of cricopharyngeal muscle with TCPM has sufficient potential to improve cricopharyngeal dysphagia, it has often carried surgical morbidity and complication compared with ECPM. However, ECPM is not yet widely done because of its rather highly qualified technique. It is likely that this endoscopic technique of posterior vertical myotomy alone does not provide sufficient opening of the upper esophageal sphincter due to postoperative adhesion of the cricopharyngeal muscle. Therefore, in this surgical procedure against cricopharyngeal dysphagia, not only myotomy but also resection of the cricopharyngeal muscle is highly required. We present a new paradigm of ECPM and discuss its advantages and applications.

Radiotherapy of the neck influences the distribution of laryngeal secretory glands.

To elucidate the influence of radiation therapy on the larynx in patients who receive radiotherapy to the neck, we observed the changes in the distribution of the laryngeal glands. Human adult larynges from patients with either laryngeal or hypopharyngeal cancer were histopathologically examined, and the changes in the glandular distribution as well as in the ratio of serous or mucous type cells were surveyed using an image analysis system. The mean ratio of the area occupied by glandular acini in the subglottic larynx was 0.182 in the non-radiation group and 0.098 in the radiation group (p < 0.001). Although no statistical difference was observed, the average density of the glands decreased and the average ratio of serous-type/mucous-type glandular cells decreased in the irradiated larynx. The glandular acini are often replaced with fibrous connective tissue and the ratio of serous-type glandular cells decreases. These results indicate that not only the voice function but also the local defence function of the larynx might be impaired after radiotherapy.

Mechanical Regulation of Human Vocal Fold Stellate Cells

Objective: It is generally accepted that tensile and compressive strains have direct effects on cell morphology and structure, including changes in cytoskeletal structure and organization. Cytoskeletons play the role of mechanoreceptor of the cells. Vocal fold stellate cells (VFSCs) in the human maculae flavae (MFe) are inferred to be involved in the metabolism of extracellular matrices essential for the viscoelasticity of the vocal fold mucosa. Our previous studies have supported the hypothesis that the tension caused by phonation (vocal fold vibration) regulates the behavior of the VFSCs. The microstructure of the intermediate filaments and the expression of their proteins were investigated in VFSCs in the MFe, which had remained unphonated since birth. Methods: Three adult vocal fold mucosae that had remained unphonated since birth were investigated by immunohistochemistry and electron microscopy. Results: The intermediate filaments of the VFSCs were fewer in number. The expression of their characteristic proteins (vimentin, desmin, and glial fibrillary acidic protein) was also reduced. Conclusion: Vocal fold vibration seems to affect VFSC morphology and structure, such as cytoskeletal structure and organization. This supports the hypothesis that vocal fold vibration regulates VFSC behavior in the human MFe. In addition to chemical factors, mechanical factors also appear to modulate VFSC behavior.

Sleep-related deglutition in patients with OSAHS under CPAP therapy

Abstract Conclusion: Continuous positive airway pressure (CPAP) therapy improved not only apnea-hypopnea during sleep and sleep structure but also sleep-related deglutition, especially respiratory phase patterns associated with deglutition. Objectives: Sleep-related deglutition and related respiratory phase patterns in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) under CPAP therapy were investigated. Methods: Deglutition during sleep was examined in 10 patients who had severe OSAHS under CPAP therapy via time-matched recordings of polysomnography and surface electromyography. Results: The mean number of swallows per hour during the total sleep time was 1.6 ± 1.3. The mean period of the longest absence of deglutition was 66.4 ± 19.6 min. Deglutition was related to the sleep stage. The mean number of swallows per hour was 6.8 ± 8.4 during stage 1 sleep, 1.1 ± 0.8 during stage 2 sleep, 0.1 ± 0.4 during stage 3 sleep, and 0 during stage 4 sleep. The deeper the sleep stage, the lower the mean deglutition frequency. The mean number of swallows per hour was 0.8 ± 0.5 during REM sleep. Most deglutition occurred in association with spontaneous electroencephalographic arousal. Swallows followed by inspiration were markedly reduced. Under CPAP therapy, sleep-related deglutition and its respiratory phase pattern had normalized.

Effect of laser arytenoidectomy on respiratory stridor caused by multiple system atrophy.

Respiratory stridor in patients with multiple system atrophy is a complication that occasionally causes nocturnal sudden death. Continuous positive airway pressure (CPAP) therapy has been proposed as an alternative to tracheostomy to treat nocturnal stridor associated with multiple system atrophy. However, some patients cannot tolerate CPAP therapy and experience sleep disturbances, even if the pressure is controlled; also, CPAP therapy can be less effective in patients with a narrow glottic opening during sleep. This report describes the effect of laser arytenoidectomy on respiratory stridor caused by multiple system atrophy.