Kazumi Motoyoshi

Restoring Vocal Fold Movement after Transection and Immediate Suturing of the Recurrent Laryngeal Nerve with Local Application of Basic Fibroblast Growth Factor: An Experimental Study in the Rat†

Objective: To evaluate the effects of basic fibro‐blast growth factor (bFGF) on the recovery of vocal fold movement and the attenuation of laryngeal muscle atrophy after transection of the recurrent laryngeal nerve (RLN).

Age-related changes in rat intrinsic laryngeal muscles: analysis of muscle fibers, muscle fiber proteins, and subneural apparatuses

We compared age-related changes in the intrinsic laryngeal muscles of aged and young adult rats by determining the number and diameter of muscle fibers, contractile muscle protein (myosin heavy chain isoforms, MHC) composition, and the morphology of the subneural apparatuses. In aged rats, both the numbers and the diameters of muscle fibers decreased in the cricothyroid (CT) muscle. The number of fibers, but not diameter, decreased in the thyroarytenoid (TA) muscle. In the posterior cricoarytenoid (PCA) muscle, neither the number nor the diameter of fibers changed significantly. Aging was associated with a decrease in type IIB and an increase in type IIA MHC isoform levels in CT muscle, but no such changes were observed in the TA or PCA muscles. Morphological examination of primary synaptic clefts of the subneural apparatus revealed that aging resulted in decreased labyrinthine and increased depression types in only the CT muscle. In the aged group, morphologically immature subneural apparatuses were found infrequently in the CT muscle, indicating continued tissue remodeling. We suggest, therefore, that age-related changes in the intrinsic laryngeal muscles primarily involve the CT muscle, whereas the structures of the TA and PCA muscles may better resist aging processes and therefore are less vulnerable to functional impairment. This may reflect differences in their roles; the CT muscle controls the tone of the vocal folds, while the TA and PCA muscles play an essential role in vital activities such as respiration and swallowing.

Incidence of long-term ipsilateral and contralateral ototoxicity following radiotherapy for nasopharyngeal carcinoma.

OBJECTIVE To characterize the long-term adverse effects of radiotherapy on the ears in patients with nasopharyngeal carcinoma (NPC), we investigated ipsilateral and contralateral ototoxicities in the external, middle, and inner ear. METHODS The records of 48 ears in 24 radiotherapy-treated NPC patients were retrospectively analyzed. Radiotherapy doses varied between 60 and 70 Gy in 2-Gy fractions at 5 fractions/week. Ototoxicities were identified by otoscope and pure-tone audiograms conducted at 2-3 month intervals for ≥12 months. The relationship between radiation dosage and sensorineural threshold deterioration was statistically compared using the Mann-Whitney U-test. RESULTS Post-radiotherapy, 50% of all ears (3 of 6) that developed severe otitis externa were on the contralateral side. There was a post-radiotherapy increase in contralateral otitis media with effusion (OME) (1-7 ears), but a decrease in ipsilateral cases (16-12 ears), with 2 ears on either side subsequently developing chronic otitis media (COM). All ears that showed sensorineural hearing loss (SNHL) before radiotherapy exhibited a further threshold deterioration of more than 15 dB. No statistically significant difference (p=0.086) in average radiation dose was seen between ears with sensorineural threshold deterioration (50.0 Gy) and those without (48.2 Gy). CONCLUSION Long-term ototoxicity following radiotherapy for NPC can occur in either the ipsilateral or contralateral ears. Pathophysiology varies between and within each side. The post-therapy increase in OME on the contralateral side was thought to be due to radiotherapy-induced Eustachian tube damage, and the sensorineural threshold deterioration in at least 4 ears was thought to be due to chronic cochlea damage secondary to COM.

Laterofixation of the vocal fold using an endo-extralaryngeal needle carrier for bilateral vocal fold paralysis.

OBJECTIVES Laterofixation of the vocal fold is a simple and reliable surgical intervention for laryngeal obstruction due to bilateral vocal fold fixation to obtain sufficient glottal space. Nevertheless, it has some technical disadvantages. This report summarizes the surgical outcomes in patients who underwent laterofixation of the vocal fold with or without the use of an endo-extralaryngeal needle carrier (EENC). METHODS A prospective study of 11 consecutive patients with bilateral vocal fold paralysis. All of the patients underwent unilateral vocal fold laterofixation. Six patients were assigned to the non-EENC group and five to the EENC group. The surgical outcomes were evaluated, including the operating time and respiratory and phonatory functions. RESULTS The operating time was 44% shorter in the EENC group and less skin incisions were required. Postoperatively, the dyspnea was eliminated in all of the patients in both groups, and the six patients who required a tracheotomy were successfully decannulated. Spirometry confirmed the improvements in %FEV(1) and %PEF in the two groups. Postoperative voice function was socially acceptable in all patients, and it tended to be better in the non-EENC group. In the EENC group, one patient developed a minor submucosal hematoma and another patient had a recurrence of dyspnea 2 months postoperatively, probably due to thread disruption. CONCLUSION The present study confirms that laterofixation of the vocal fold with or without EENC relieves laryngeal obstruction. Surgery with the EENC is simpler and quicker than the conventional procedure. However, the surgery with the EENC has some disadvantages, including likely problems with the thread and downward traction on the vocal fold. Surgeons should be aware of these possible shortcomings.

A Case Report of Aspergillosis of the Larynx

Mycosis localized in the larynx is relatively rarely observed, and only a small number of cases have been reported. We encountered a 69-year-old male with laryngeal mycosis due to Aspergillus. He visited our department due to hoarseness/abnormal laryngeal sensation. At the first consultation, electronic laryngoscopy showed a white lesion anterior to the membranous portions of the bilateral vocal folds. Based on the results of biopsy, a diagnosis of laryngeal aspergillosis was made. He was treated with the oral administration of an antifungal drug on an outpatient basis, and showed a tendency toward improvement, however, the fungus partly remained, and additional resection was performed using a laser by laryngo-microsurgery. He has since remained under follow-up observation.

Use of the Microdebrider for Reinke's Edema Compromising the Airway Compromise

Reinkes edema is a condition characterized by diffuse polypoid changes in the subepithelial superficial lamina propria of the vocal cords, which is usually treated using the minimally invasive microflap technique. However, in patients with dyspnea, the epithelium has often undergone pathological changes due to repeat infection and hemorrhage. During the resection of such bulky, inflamed lesions, the operative field is compromised by bleeding, which can result in complications. We report two patients with severe Reinkes edema who presented with a chief complaint of dyspnea. In both patients, emergency tracheostomy was performed immediately before the curative resection of the lesion with the laryngeal microdebrider. The procedures were promptly completed with good visualization. No complication occurred and the patients were satisfied with the vocal outcome one month after the treatment. Although few reports are available on the use of the microdebrider in inflammatory lesions of the vocal cords, our experience showed its usefulness in selected cases of Reinkes edema.

Laryngeal Paralysis in Children

Masamitsu Hyodo, Takahiko Yamagata, Kazumi Motoyoshi and Aki Taguchi Recurrent laryngeal nerve paralysis in children is a relatively rare disease. Its clinical features in children are considered dissimilar to those in adults. Here we present 11 cases of children with recurrent laryngeal nerve paralysis and discuss the manner of treatment for this disease. Clinical features compared and found to differ with those in adults are summarized as follows: 1) congenital paralysis is the most common cause, 2) bilateral paralysis is frequent, 3) congenital systemic abnormalities are frequently combined, 4) respiratory disorder is the most critical symptom especially in infants, 5) vocal cord movement ordinarily recovers in a few years especially in patients with congenital paralysis. Management strategies should be focused on the maintenance of a safe and stable airway and the acquisition of intelligible speech. Less traumatic laterofixation of the vocal cord by Ejnells procedure is a preferable surgical treatment for prolonged respiratory disorder due to bilateral laryngeal paralysis.