Seth H. Dailey

A Laryngeal Dissection Station: Educational Paradigms in Phonosurgery†

Objectives: To introduce a new tool for phonosurgical training and education. A multitude of innovations in complex laryngeal surgery has catalyzed new educational initiatives. Establishing dexterity in phonomicrosurgery is often difficult to achieve while working on patients because of the narrow margin for success. Furthermore, laryngoplastic phonosurgery and open partial laryngectomy require sophisticated knowledge of precise anatomic relationships, which can be difficult to express in images. Finally, many teaching programs do not have a high volume of these procedures, and there is a significant need to transmit this information in continuing education courses.

Endoscopic measurement of vocal fold movement during adduction and abduction.

Objectives/Hypothesis: Whereas vibration of the vocal folds has been analyzed and modeled in detail, less attention has been paid to quantifying the slower motions of abduction and adduction. Because these gestures reflect neuromuscular function, cartilage geometry, and joint mobility, objective measurement might improve assessment and treatment of patients with neuromuscular or structural disease.

Adduction arytenopexy for vocal fold paralysis: indications and technique.

Adduction arytenopexy was designed as an innovation to arytenoid adduction, however the pragmatic issues regarding patient selection for these procedures has not been comprehensively assessed. A prospective examination was performed on 100 consecutive patients who had undergone laryngoplastic phonosurgical reconstruction for paralytic dysphonia. Seventy-seven of 100 (77 per cent) were judged pre-operatively to gain potentially significant phonatory enhancement from an arytenoid procedure. Fifty-six of 77 (73 per cent) underwent adduction arytenopexy; 17 of 77 (22 per cent) were judged pre-operatively to have inadequate respiratory abduction of the contralateral arytenoid and two out of 77 (three per cent) had athletic aerodynamic requirements. In another two out of 77 (three per cent), there was a chance of favourable reinnervation and thus it was not the preferred method. The majority of patients were judged pre-operatively to gain potentially substantial phonatory enhancement from an arytenoid procedure. However, in this series, approximately 25 per cent of the patients were considered to be unsuitable candidates for an arytenoid medializing procedure, primarily because it was deemed that the operation could result in an inadequate airway.

Technique of en block laser endoscopic frontolateral laryngectomy for glottic cancer.

During the last 30 years, there has been expansion of the role of endoscopic partial laryngectomy procedures since Jako, Strong, and Vaughan explored the possibilities of CO2 laser microlaryngeal procedures. Despite the fact that a number of investigators have verified the validity of endolaryngeal laser resection of mid‐sized glottic cancer, there are many who are unfamiliar with the technique and others who are uncomfortable with sectioning the tumor to facilitate its resection. In the past 3 years, 15 patients underwent successful en block resection of mid‐sized glottic cancer (T1b 2, T2b 11, T3 2). Because en block resection is more consistent with open oncologic approaches, this method should widen the acceptance of this approach in selected lesions. The nuances of en block endoscopic frontolateral laryngectomy are presented with the hope that more surgeons will adopt this philosophy as an aspect of their armamentarium.

GRADATION OF STIFFNESS OF THE MUCOSA INFERIOR TO THE VOCAL FOLD

During phonation, energy is transferred from the subglottal airflow through the air/mucosa interface that results in the propagation of the mucosal wave in the vocal fold. The vocal fold is soft, and the subglottal mucosa is stiff. We hypothesize that it is highly improbable that there is a rigid boundary between the tissue structures, with a sudden drop in stiffness; and that a gradual change would be more likely to support the efficient transfer of energy from the airflow to the mucosal wave. Our objective was to test this hypothesis by quantifying the change in mucosa stiffness with respect to anatomical position. In this initial study, using five pig larynges, a series of point-specific measurements of mucosa stiffness were taken in a line from the midpoint of the vocal fold toward the trachea. A modified linear skin rheometer adapted for laryngeal elasticity measurement applied shear stress to a series of seven positions at 2-mm intervals starting from the midmembranous vocal fold medial surface. A sinusoidal shear force of 1g was applied at each point, and resultant displacement curve logged. Using a regression algorithm, the stiffness of the tissue was derived in units of grams force per millimeter displacement. Five readings were taken at each position. The results indicate that there is a linear increase in stiffness with respect to position, increasing as the measurements are taken further from the vocal fold. There is a gradual change in stiffness of the subglottal mucosa of a pig larynx.

Office-based pulsed dye laser treatment for hemorrhagic telangiectasias and epistaxis

INTRODUCTION Treatment of epistaxis as a consequence of hemorrhagic telangiectasias remains a challenging problem for the otolaryngologist. The most common cause or origin of this condition is hereditary hemorrhagic telangiectasia (HHT). This syndrome (also labeled Osler-Weber-Rendu syndrome) is characterized by the triad of multiple telangiectasias, repeated hemorrhage, and a family history of such occurrences. Historically, treatment consisted of a septodermoplasty. Since the early 1990s, endonasal laser treatment of the telangiectatic vessels has demonstrated efficacy. The limitations of these procedures have included the need for repeated procedures with the patient under general anesthesia. In the present report, we outline a novel technique for performing laser treatment of these vessels on an outpatient basis using 585-nm pulsed dye laser (PDL) treatment.

The Anisotropic Elasticity of the Human Vocal Fold

Objective: To verify the anisotropic nature of the vocal folds by reproducing an experiment led by Rholfs that measured vocal fold elasticity in the transverse and longitudinal directions. To present a physiological explanation of the measured phenomena using immunochemical results. nMethods: 6 cadaveric human excised larynges were hemi-sectioned in the mid-sagittal plane exposing the vocal folds, and orthogonal measurements of tension made at 3 equally spaced points. Immunohistochemistry carried out by Ichiro Tateya was used to visualise collagens and elastins in the deep layer of the lamina propria. nResults: The LSR results indicate that the measured elasticity of the vocal folds are highly anisotropic. The immunohistochemistry results show that there is a strong alignment of collagens and elastins along the longitudinal axis of human vocal folds. nConclusion: The measured anisotropic behaviour is due to the alignment of collagens & elastins in the lamina propria.

Pharmacotherapy of UES Spastic Disorder

Botulinum toxin injections have been used in upper esophageal dysfunction since 1994, currently with several hundred reported cases of swallowing improvement. Several themes are present in the majority of the published case series, relative ease of injection technique, high reported success rates and very low complication rates. The final consistent theme was a call for large series and prospective research to guide clinical care. The combination of low complication rate combined with the relative ease of performing the procedure compared to a surgical cricopharyngeal myotomy makes botulinum toxin injection an appealing therapeutic option in appropriate patients.