Hiroyuki Fukuda

Lubrication Mechanism of the Larynx during Phonation: An Experiment in Excised Canine Larynges

To evaluate how the viscosity of the laryngeal mucus influences vocal fold vibration, two fluids of differing viscosity were applied separately to excised canine larynges and experimental phonation was induced. Vibration of the vocal folds was measured by use of a laryngostroboscope and an X-ray stroboscope. With the high viscosity fluid, the amplitude of vibration of the free edge and the peak glottal area was decreased while the open quotient was increased. Because the viscosity of this fluid affected the wave motion of the vocal fold mucosa, changes in viscosity of the mucus may be involved in causing such disorders as hoarseness, in the absence of apparent changes in the vocal folds themselves.

Dilator Naris Muscle

The human nose is an important organ of respiration which by virtue of its valvular influence becomes a significant effector of respiratory resistance over a wide range of ventilatory requirements. In man its effectiveness in this regard is related to its flow limiting segment (FLS) located at the limen nasi. Its passive valvular effect is additionally modified by active respiratory contractions of the dilator naris muscle (DNM) controlled through the VII cranial nerve by the brain stem respiratory center. Its behavior, quantitatively determined in human beings and experimental animals, is summarized. 1) In man, phasic DNM activity operates during eupneic nasal breathing and varies directly with ventilatory resistance. 2) The elimination of all measurable ventilatory resistance results in complete cessation of DNM activity. 3) Over time, reduced resistance produces difficulty in reestablishing dilator function once it is physiologically lost. 4) DNM respiratory activity is modified by pulmonary mechano-and pressure-receptors via afferent vagal pathways. The response of nasal dilators in valvular control, therefore, appears dependent on the physiologic integrity of the vagus nerves. It is our belief that nasal valvular control has not previously been appreciated in this context.

Voice prognosis after liquid and solid silicone injection

A study was undertaken to determine the voice prognosis in 51 of the 408 patients with unilateral recurrent laryngeal nerve paralysis who had visited the Department of Ear, Nose and Throat at Keio University between 1977 and 1984. The 51 patients were divided into three groups: 18 patients without silicone injection, 15 with a silicone liquid implant, and 18 with a silicone solid implant. Data are provided to show that (1) both types of silicone implant are tolerated by the body and effective in improving voice and that (2) the liquid implant is ultimately absorbed and therefore useful for temporary voice improvement in patients in whom the prognosis for vocal fold paralysis is not known, whereas the solid implant is not absorbed and is therefore effective in the long term when recovery can be ruled out.

Video-Assisted Rigid Endoscopic Laryngosurgery: Application to Cases with Difficult Laryngeal Exposure

In some cases of microlaryngosurgery, laryngeal exposure with a direct laryngoscope is difficult because of a variety of reasons. In such cases, we now use a long rigid endoscope inserted into the side tube of the direct laryngoscope together with a video system. The lesion can be removed while the phonosurgeon observes the magnified images of the larynx on the video monitor. We describe the surgical procedure together with the preoperative and postoperative evaluation of vocal function in 13 patients with benign laryngeal lesions. A good surgical and vocal outcome was achieved in all cases. The method appeared to be useful for treating dysphonia in patients in whom it was difficult to expose the larynx with a direct laryngoscope.

Papillary Adenocarcinoma Possibly Arising from an Intraductal Papilloma of the Parotid Gland

We report a case of a 70-year-old female with a papillary adenocarcinoma which we believe to have originated from an intraductal papilloma of the parotid gland. A few cases of intraductal papilloma of a minor salivary gland have been reported; however, to our knowledge, intraductal papilloma and, hence, adenocarcinoma originating from an intraductal papilloma of the parotid gland, have never been described.

Digital image processing of laryngeal lesions by electronic videoendoscopy

Objectives To present electronic videoendoscopy of the larynx with digital image processing and to discuss this endoscopic technique from the standpoint of diagnostic usefulness of laryngeal lesions.

Study of movements of individual structures of the larynx during swallowing.

OBJECTIVEnThe purpose of this study was to reveal movements of individual structures of the larynx during swallowing.nnnMETHODSnSubjects were 7 healthy adults, aged 24 to 32 years (average 27 years), who had no organic or functional disease of the pharynx and larynx and 2 adults with unilateral recurrent nerve palsy, aged 49 and 60 years, respectively. We used the Toshiba IIDR system, which is composed of an X-ray TV system and a digital image managing circuit. One-fifth diluted Omnipark 300 was used as contrast medium (lohexol), with 15 cc for each swallow. The mask image for subtraction was designated as the frame before laryngeal elevation during swallowing for subtraction. We obtained the images for observation and analysis after subtracting the mask image from continuously obtained images. These images were captured into a personal computer at 30 frames per s and thereafter frame-by-frame observation and analysis were performed by means of NIH image 1.56.nnnRESULTSnWe observed that the vocal folds underwent a series of movements during swallowing. (1) They adduct slowly and do not ascend; (2) then begin to ascend and continue adducting; whereby (3) they abduct for a moment while ascending. (4) Again, they adduct and achieve closure. (5) While maintaining closure, vocal folds elevate further to reach their maximal elevation; and (6) begin to abduct rapidly while maintaining maximal elevation. Finally, (7) they begin to descend and undergo repeated irregular abduction and adduction while descending. In examining the relationship between closure and opening at levels of the vocal fold and false vocal fold, we found that closure at the false vocal fold level precedes that at the vocal fold level and that opening at the vocal fold level precedes that at the level of the false vocal fold.nnnCONCLUSIONnClosure of the false vocal fold level appears important in the protection of the lower respiratory tract during swallowing.

Actinomycosis of the larynx

Actinomycosis is a disease characterized by a chronic suppurative and granulomatous process which tends to form multiple pyogenic draining sinus tracts. The most common site in which it occurs is the cervico-facial region, especially in the submandibular area. The exudates from the fistulous tracts usually contain yellow granules known as sulfur granules, which can be considered as a hallmark of actinomycosis. We report a rare case of laryngeal actinomycosis which occurred in a 68-year-old male who had been irradiated 8 years before due to laryngeal carcinoma. During the admission, the patient was also diagnosed as being a myelodisplastic syndrome carrier. The patient was treated successfully with penicillin 10 million IU administered daily over 40 days. The etiologic agents, predisposing factors, diagnostic procedures, and available treatments are discussed, and the pertinent literature is reviewed herein.

Displacement of the Ventricular Fold Following Cordectomy

In order to avoid radiation and its undesirable side effects, we have employed surgical techniques for treatment of early glottic cancer when the lesion is confined to one membranous cord (Fukuda, Saito, Sato, and Kitahara: J. Jpn. Bronchoesophagol. Soc. 30: 7-14, 1979; Fukuda and Saito: Otologica 26: 434-436, 1980; Fukuda, Kawaida, Ohki, Kawasaki, Kita, and Tatehara: J. Jpn. Bronchoesophagaol. Soc. 39: 139-144, 1988). Laser is one of the most popular techniques and it has been accepted as the first choice by many authors (Annyas, Overbeek, Escajadillo, and Hoeksema: Laryngoscope 94: 836-838, 1984; Mcguirt and Koufman: Arch. Otolaryngol. Head Neck Surg. 113: 501-505, 1987; Tsuji, Fukuda, Kawaskai, Kawaida, and Kanzaki: Keio J. Med. 38: 413-418, 1989). However, some cases are difficult to approach by direct laryngoscopy, requiring an external way to expose the lesion. In these cases, cordectomy by laryngofissure is the method of choice, but the function of the glottis could be improved by replacing the excised cord displacing the ventricular fold. This technique, designed by the authors, was carried out in 22 patients and the results from the viewpoint of phonodynamics, voice quality, and cure rate are discussed in this study. The results are encouraging and we believe that this method is a very reasonable alternative to the laser when such equipment is not available. We also believe that late side effects and oncogenic problems associated with radiation are important points to be considered, especially in patients of relatively younger age.

Changes in the Respiratory Activity of the Cricothyroid Muscle with Intrathoracic Interruption of the Vagus Nerve

Why does the paralyzed vocal cord sometimes lie in a partly abducted or interinediate position if the interruption of its motor innervation occurs within the chcst rather than in the neck? The paramedian position that results from interruption of the recurrent laryngeal nerve (RLN) within its cervical portion has been amply documented and is generally attributed to the adductor action of the cricothyroid muscle.