Gerald S. Berke

Laryngeal modeling: theoretical, in vitro, in vivo.

Because the larynx is situated anatomically in an area which is difficult to measure and visualize, theoretical, in vitro, and in vivo models are used in laryngeal research. Vocal fold vibration was studied in anesthetized dogs, while electrically stimulating independently the superior and recurrent laryngeal nerves under conditions of constant airflow. Photoglottographic (PGG), electroglottographic (EGG), and subglottic pressure signals were obtained while stroboscopically photographing the larynx. Specific points along PGG, EGG, and subglottic pressure waveforms were correlated with laryngeal events which occurred during vibration. The canine larynx, in an experimentally produced phonatory mode, vibrates in a two mass (upper and lower margin) system and appears comparable to modal human voice production. The recorded glottogrophic waveforms from experimentally produced phonation in the canine are similar to signals recorded from humans. However, observed differences can be related to anatomic differences.

Radial forearm free flap pharyngoesophageal reconstruction.

Objectives This study evaluates the outcome of pharyngoesophageal reconstruction using radial forearm free flaps with regard to primary wound healing, speech, and swallowing in patients requiring laryngopharyngectomy.

Research Priorities in Spasmodic Dysphonia

Objective To identify research priorities to increase understanding of the pathogenesis, diagnosis, and improved treatment of spasmodic dysphonia. Study Design and Setting A multidisciplinary working group was formed that included both scientists and clinicians from multiple disciplines (otolaryngology, neurology, speech pathology, genetics, and neuroscience) to review currently available information on spasmodic dysphonia and to identify research priorities. Results Operational definitions for spasmodic dysphonia at different levels of certainty were recommended for diagnosis and recommendations made for a multicenter multidisciplinary validation study. Conclusions The highest priority is to characterize the disorder and identify risk factors that may contribute to its onset. Future research should compare and contrast spasmodic dysphonia with other forms of focal dystonia. Development of animal models is recommended to explore hypotheses related to pathogenesis. Improved understanding of the pathophysiology of spasmodic dysphonia should provide the basis for developing new treatment options and exploratory clinical trials. Significance This document should foster future research to improve the care of patients with this chronic debilitating voice and speech disorder by otolaryngology, neurology, and speech pathology.

Early experience with percutaneous tracheotomy

Early reports of a percutaneous dilatational technique for tracheotomy tube placement have been encouraging. This method uses a needle for placement into the trachea, a J‐tipped guidewire, and progressively larger dilators to widen the stoma for insertion of a tracheotomy tube.

Selective Laryngeal Adductor Denervationreinnervation: A New Surgical Treatment for Adductor Spasmodic Dysphonia

During the past decade, botulinum toxin (Botox) has emerged as the accepted treatment for adductor spasmodic dysphonia (ASD). This therapy, which produces bilateral weakness of the thyroarytenoid muscle, undoubtedly produces physiologic effects that are beneficial to patients with ASD. However, it also has important limitations, including the need for repeated injections, the unpredictable relationship between dosage and response, and the possibility of short-term swallowing and voice problems. In this study, we will report our preliminary experience with a new surgical treatment for ASD. In this new procedure, the adductor branch of the recurrent laryngeal nerve is selectively denervated bilaterally, and its distal nerve stumps are reinnervated with branches of the ansa cervicalis nerve. Each of the patients was followed for at least 12 months; the median follow-up is 36 months. The outcome of the operation in 21 consecutive patients is reported. Nineteen of the 21 patients were judged to have an overall severity of dysphonia that was “absent to mild” following the procedure. Only 1 patient underwent further treatment with Botox postoperatively. The implications of this new procedure for ASD are discussed.

Treatment of vocal fold granuloma using botulinum toxin type A.

Contact granuloma of the vocal folds has been associated with abnormal use of the voice, and acid reflux may exacerbate the inflammatory process. Treatments have included voice therapy and antireflux measures. Surgical excision is considered in patients who do not respond to medical management.

Lamina Propria Replacement Therapy with Cultured Autologous Fibroblasts for Vocal Fold Scars

OBJECTIVES: To develop a canine model of vocal fold scar and to evaluate its treatment with lamina propria replacement therapy using autologous cultured fibroblasts. MATERIALS AND METHODS: Full thickness of the lamina propria layer in canine vocal folds was injured with a laser. Fibroblasts were cultured and expanded in the laboratory from a buccal mucosal biopsy. The scarred vocal folds were treated with 3 weekly injections of fourth, fifth, and sixth passage autologous fibroblasts. Mucosal waves and acoustic parameters were measured at baseline, after scarification, and several months after injection therapy. Histologic evaluation of the vocal folds for fibroblasts, collagen, elastin, reticulin, and hyaluronic acid was performed. RESULTS: Nine beagle dogs were used, and 1 animal served as control. Vocal fold scarring resulted in absent or severely limited mucosal waves and significantly worse acoustic parameters. Significant improvements in mucosal waves and acoustic parameters were obtained after lamina propria replacement therapy. After therapy, mucosal waves became normal in 4 animals and near normal in the other 4. No statistical difference was found in mucosal waves between baseline and post-therapy. All animals tolerated therapy without complications. The treated vocal folds demonstrated an increased density of fibroblasts, collagen, and reticulin, a decreased density of elastin, and no change in hyaluronic acid. CONCLUSIONS AND SIGNIFICANCE: Therapeutic options for vocal fold scars are limited. Lamina propria replacement therapy in the form of autologous cultured fibroblasts improves mucosal pliability and returns normal or near normal mucosal waves in experimentally scarred vocal folds. This novel therapeutic modality may hold new promise for treating vocal fold scars.

Epithelial differentiation of adipose‐derived stem cells for laryngeal tissue engineering

One potential treatment option for severe vocal fold scarring is to replace the vocal fold cover layer with a tissue‐engineered structure containing autologous cells. As a first step toward that goal, we sought to develop a three‐dimensional cell‐populated matrix resembling the vocal fold layers of lamina propria and epithelium.

Ansa Cervicalis Nerve: Review of the Topographic Anatomy and Morphology

In recent years, there has been a proliferation of techniques utilizing the ansa cervicalis nerve to reinnervate the paralyzed larynx. The anatomic course and morphology of the ansa cervicalis are complicated by the variable course and location along the great vessels of the neck, as well as the significant differences observed in the arrangement of its contributing roots and regional branching patterns. Herein, we review the surgical anatomic course of ansa cervicalis and its innervation of the muscles of the neck, and develop specific recommendations with respect to the use of this nerve in laryngeal reinnervation.

Medial surface dynamics of an in vivo canine vocal fold during phonation

Quantitative measurement of the medial surface dynamics of the vocal folds is important for understanding how sound is generated within the larynx. Building upon previous excised hemilarynx studies, the present study extended the hemilarynx methodology to the in vivo canine larynx. Through use of an in vivo model, the medial surface dynamics of the vocal fold were examined as a function of active thyroarytenoid muscle contraction. Data were collected using high-speed digital imaging at a sampling frequency of 2000 Hz, and a spatial resolution of 1024 x 1024 pixels. Chest-like and fry-like vibrations were observed, but could not be distinguished based on the input stimulation current to the recurrent laryngeal nerve. The subglottal pressure did distinguish the registers, as did an estimate of the thyroarytenoid muscle activity. Upon quantification of the three-dimensional motion, the method of Empirical Eigenfunctions was used to extract the underlying modes of vibration, and to investigate mechanisms of sustained oscillation. Results were compared with previous findings from excised larynx experiments and theoretical models.