Hironobu Kurokawa

Infraglottic aspect of canine vocal fold vibration: Effect of increase of mean airflow rate and lengthening of vocal fold

The mucosal upheaval (MU), where the mucosal wave starts and propagates upward, appears only when the vocal fold vibrates. The location of the MU histologically and the effect of changes in mean air flow rate (MFR) and vocal fold length on occurrence of the MU were studied in twelve excised canine larynges. The lower surface of the vocal fold was marked to serve as a landmark for subsequent study. Cricothyroid approximation was performed to lengthen the vocal fold. After taking high-speed pictures or recording stroboscopic images from the tracheal side, a small cut wound was made at the mark. This wound served to compare the position of the MU with the histologically identified location of the mark. The larynx was then sectioned in the frontal plane. Before lengthening the vocal fold, the MU occurred on the area where the lamina propria became thinner and where the muscular layer neared the epithelial layer. After lengthening the vocal fold, the MU actually shifted medially compared with its original position. The subglottic area surrounded by the bilateral MUs became longer and thinner. Whether or not complete glottal closure during a vibratory cycle was achieved did not alter these findings. In contrast, with a fixed vocal fold length the MU appeared more laterally as MFR increased, but, based on the relation with the mark, its location on the vocal fold did not change from its original position before increase of MFR.

Vocal fold vibration of the canine larynx: Observation from an infraglottic view

Summary The authors studied the vibratory action of the canine vocal fold from the tracheal side utilizing high-speed cinematography. Five excised canine larynges were used, and the lower surface of the vocal fold of three of them were marked with India ink as a tracer of a specific point on the vocal fold. A mucosal prominence, called the mucosal upheaval, appeared between the anterior commissure and the vocal process. Vibration was not seen below the mucosal upheaval. The mucosal wave started to move medially from just above the mucosal upheaval. The mucosal wave then became the free edge (lower lip) and collided with that of the other side at the midline. After collision, the lower lip moved upward to become the upper lip. At the same time, a part of the lower lip reflected laterally. The mucosal wave of the next cycle started from just above the mucosal upheaval during an opening phase. The mucosal upheaval vibrated with a low amplitude and with an earlier phase than the other portion of the vocal fold. The increase in tension of the vocal fold did not change the basic vibratory pattern of the mucosal upheaval, the mucosal wave, or the free edge. However, analysis of the mark before and after the increase in tension revealed that the mucosal upheaval occurred more medially or above when the vocal fold tension increased.

A Case in the Status of Pre-DIC with Intracranial Complications Caused by Paranasal Sinusitis.

A case with intracranial complications caused by paranasal sinusitis, who was also diagnosed with pre-Disseminated Intravascular Coagulation syndrome (pre-DIC). A 21-year-old male had complained of headache, high grade fever, general convulsions and consciousness disturbances. At the first examination his left superior eye lid and cheek were slightly swollen. The emergent CT revealed diffuse soft tissue density in the left ethmoidal, maxillary and sphenoidal sinuses and a low density area in the left frontal lobe. Laboratory examination of blood showed white blood cells increased, platelets decreased and fibrin degenerated products increased. These data suggested a status of pre-DIC. Moreover, analysis of cerebro-spinal fluid suggested bacterial meningitis. In order to control of sinusitis as the primary lesion, endoscopic sinus surgery was performed immediately. Not only intensive chemotherapy but also precise suction removal of the purulent secretion in the sphenoidal sinus under endoscopy were effective for control of inflammation. Nevertheless, the patients consciousness level and left hemiplegia worsened and a head-CT revealed a subdural abscess. Neurosurgical drainage was successful and the patient returned to normal. Ten weeks after surgery the patient was discharged with no functional disorder. The following examination revealed no trouble in the paranasal sinuses. This case confirmed the usefulness of endoscopic sinus surgery for the treatment of paranasal lesions and the importance of follow-up in cases of intracranial complications.

Postoperative Results of Middle Ear Cholesteatoma.

Surgical treatment of middle ear cholesteatoma was evaluated from the point of postoperative hearing and recurrence of cholesteatoma. Of the 36 ears operated on in the previous 5 years and 5 months, intact canal wall tympanoplasty was performed in 27 ears, and tympanoplasty with posterior canal wall removal in 9 ears. The patients were evaluated for a follow-up period of more than 6 months after tympanoplasty. The rate of success in hearing improvement was 82.4% according to the criteria of the Japan Otological Society. Recurrence of the cholesteatoma was found in 2 ears (5.6%), which had been treated by intact canal wall tympanoplasty. A retraction pocket in the attic was found in 5 ears (17.9%), following intact canal wall tympanoplasty. Reconstruction of the attic defect with cartilage and obliteration of the mastoid cavity were useful in the prevention of postoperative retraction pocket.

Pliability of the Vocal Fold Mucosa in Relation to the Occurrence of the Mucosal Upheaval

Yoshimi Kadota, Hironobu Kurokawa and Eiji Yumoto Vocal fold vibration has been considered to be a transmission of mucosal waves which move upward from the mucosal upheaval. The mechanism of the occurrence of the mucosal upheaval has not been known yet. The purpose of this study was to relate the pliability of the mucosa to the occurrence of the mucosal upheaval. In addition, a histological basis for the occurrence of the mucosal upheaval was investigated. Five mongrel dogs were used in the experiment. After administration of an intramuscular Ketaral injection, the larynx was excised and divided vertically into two segments (hemilarynges) . Pliability of the vocal fold mucosa was measured at 5-7 points ranging from the free edge to 8 mm below the edge at the middle, anterior forth and posterior forth of the membranous portion. Following the pliability measurements, each hemilarynx was fixed in formalin, sectioned in the frontal plane and stained for histologic examination. Results were summarized as follows : 1) The free edge showed the greatest pliability. The pliability of the mucosa became smaller as the edge became further. The mucosa at 3 mm below the free edge showed the least pliability. 2) The mucosa at the middle of the membranous portion had a greater pliability than that at the anerior and the posterior forth. 3) The lamina propria of the mucosa was thinnest at 3-4 mm below the free edge. At this thinnest point, the muscle layer was closest to the epithelial layer.

Two cases of steroid dependent sensorineural hearing loss.

A 32-year-old housewife developed sudden bilateral hearing loss. Hearing of the right ear was improved by steroid administration but not that of the left ear. A 37-year-old male printer lost the hearing of his right ear after diving. Exploratory tympanotomy proved rupture of the round window, which was closed with perichondrium. However, no improvement of hearing had occurred four weeks after the operation. Steroid therapy was tried and his hearing improved. The hearing of these two patients was depended on the dose of steroid : an increase in the dose improved hearing and a decrease worsened it. The etiology of this disease is not clear, but may be related to autoimmunity.

Results of surgery for middle ear cholesteatoma.

Operative findings and results in cases of middle ear cholesteatoma were analyzed with special reference to postoperative hearing and recurrence of cholesteatoma. Of the 242 ears operated on in the past 9 years and 9 months, intact canal wall tympanoplasty was performed in 114 ears, tympanoplasty with the posterior canal wall removal in 81 ears, and radical mastoidectomy in 47 ears. Of the 139 ears observed for more than 6 months after tympanoplasty, postoperative hearing was improved in 34 ears (24.5%), decreased in 15 ears (9.3%)and still in the range of the preoperative level in 90 ears (66.2%). Recurrence of the cholesteatoma was found in 15 ears (6.2%), five of which had been treated by radical mastoidectomy. Though therewere no such recurrences in 46 patients treated by staged intact canal wall tympanoplasty, a retraction pocket which was considered to be a precursor of cholesteatoma was found in seven cases (15.2%). In order to avoid a etraction pocket in intact canal wall tympanoplasty, closure of the attic accompanied by obliteration of the mastoid cavity is advised.