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C T Sasaki

Publications and source records attributed to C T Sasaki.

At least 19 recordsLinked to original sources

Squamous cell carcinoma arising in a thyroglossal duct cyst.

Carcinoma arising in a thyroglossal duct cyst is a rare event, occurring in less than 1% of abnormalities of the thyroglossal duct. To date, there have been approximately 100 cases reported, with papillary carcinoma accounting for the vast majority. Squamous cell carcinoma, on the other hand, is an even rarer event. Its clinical course in the elderly, consisting of recurrent drainage and suppuration, may distinguish it from other neoplastic conditions of thyroglossal duct cyst. We present a 65-year-old man with squamous cell carcinoma in a recurrently discharging thyroglossal duct cyst to illustrate important distinguishing clinical features of this condition.

Aged

Effective head and neck tumor markers. The continuing quest.

To evaluate the clinical value of two serologic tumor markers, squamous cell carcinoma-associated antigen and plasma lipid-bound sialic acid, for identifying cancers of the head and neck, plasma specimens were obtained from patients receiving care for untreated newly diagnosed cancers of the head and neck, routine surveillance for recurrence, or treatment for chronic nonmalignant otolaryngologic conditions. Using identical methods at two institutions, levels of both markers were determined blind to diagnoses for patients with biopsy-proven cancers of the head and neck (n = 134) and for those defined as cancer free based on clinical evaluation for 6 months (n = 140). Disease status was determined blind to tumor marker level results. Cancer prevalence was 48.9%. Applying standard normal limits used alone, plasma lipid-bound sialic acid test sensitivity was 63.4% and specificity was 77.9%. For squamous cell carcinoma-associated antigen alone, test sensitivity was 27.6% and specificity was 85.0%. Neither test alone appears sensitive enough to effectively detect early cancers of the head and neck. When the results of both tests in series combination were positive, sensitivity was 18.7% and specificity was 95.0%. If either was positive in parallel combination, sensitivity was 72.4% and specificity was 68.0%. Further evaluation is required that applies different definitions of normal and determines longitudinal changes with disease status.

Antigens, Neoplasm

Posterior cricoarytenoid muscle denervation.

Vocal fold paralysis most commonly results from injury to the recurrent laryngeal nerve. The length of time required for denervation atrophy would be useful in planning reinnervation procedures. Given the absence of long-term data on the status of the canine posterior cricoarytenoid muscle following denervation, this study was undertaken. The results indicate that muscle atrophy does not occur for at least 1 year following denervation.

Animals

Quinine-induced tinnitus in rats.

Quinine ingestion reportedly induces tinnitus in humans. To expand our salicylate-based animal model of tinnitus, a series of conditioned suppression experiments was performed on 54 male-pigmented rats using quinine injections to induce tinnitus. Quinine induced changes in both the extent of suppression and recovery of licking, which followed a pattern that paralleled those produced after salicylate injections, and which may be interpreted as the result of tinnitus perception in animals. These changes depended on the dose and time schedule of quinine administration. Additionally, the calcium channel blocker, nimodipine, abolished the quinine-induced effect in a dose-dependent manner.

Animals

Pacing parameters of the canine posterior cricoarytenoid muscle.

The electrical pacing of laryngeal tissue consists of many uncharted parameters. We carried out several acute experiments in the canine model to narrow parametric ranges to serve future research and development in this field. Our findings were as follows. Stimulation intensities greater than 6 V caused tissue damage. Optimum stimulation frequency ranged from 60 to 90 Hz. Optimum pulse duration was 2.0 milliseconds. Biphasic stimulation reduced accumulation of electrical charge at the electrodes.

Animals

Laryngeal anatomy and physiology.

Much has been learned about the normal function of the larynx. As is perhaps obvious from our article, much, much more needs to be learned about its function in altered and disease states.

Adult

Laryngeal chondrosarcoma: incidence, pathology, biological behavior, and treatment.

Chondrosarcoma is the most common mesenchymal tumor of the larynx and approximately 200 cases have been collected in the world medical literature. It is less aggressive in the larynx than elsewhere: cervical or distant metastases are rare (8.5%), and although local recurrences are not uncommon, they are not catastrophic. A retrospective study was made on eight cases of laryngeal chondrosarcoma. Three cases had originally been diagnosed as idiopathic vocal cord paralysis, possibly because of early involvement of the cricoarytenoid joint or the distal portion of the recurrent nerve. This fact emphasizes the need for accurate laryngeal computed tomography in cases of vocal cord paralysis of unknown origin. Surgical excision is the treatment of choice for laryngeal chondrosarcoma, and conservative techniques may sometimes be appropriate. Supraglottic laryngectomy may be the technique of choice in the rare cases of epiglottic involvement.

Adult

Longitudinal voice quality changes following Isshiki thyroplasty type I: the Yale experience.

Longitudinal voice quality changes following Isshiki thyroplasty type I were investigated in a group of 13 patients exhibiting unilateral vocal fold paralysis. Thyroplasty type I medializes the paralyzed fold by using a Silastic implant for external lateral compression of the abducted fold. No perioperative complications were experienced. We observed significantly higher voice fundamental frequency, significantly louder voice intensity, and significantly longer maximum phonation time, both immediately following phonosurgery and up to 3 months postoperatively. Surgical refinements of thyroplasty type I are described.

Adult

Le Fort I osteotomy approach to the skull base.

Horizontal osteotomy allows the surgeon to safely down-fracture the maxilla for wide exposure of the central skull base. This surgical approach is easily extended posteriorly in the midline to include the clivus and the arch of C1, providing 8 cm of horizontal anterior exposure and 5 cm of posterior. Wide operative exposure and a low rate of complications afford superior functional and cosmetic preservation in removing tumors of the central cranial base.

Adolescent

Development of laryngeal function: etiologic significance in the sudden infant death syndrome.

Recent clinical evidence implicates transient upper airway obstruction as a cause of potentially fatal cardiorespiratory disturbances. This investigation identifies age-related neurologic mechanisms which may be pertinent to the production of abnormal laryngeal closure as a possible cause of unexpected infant death. A period of transient laryngeal hyper-excitability is identified in pups 50--75 days post-natally. The mechanism of the hyper-excitable state resulting in increased risk of laryngeal spasm, appears related to: 1. the completion of central synaptic maturation: 2. transient reduction in central latency; and 3. a reduction in central inhibition. Such observations provide clues to neurologic vulnerability occurring not immediately after birth, but during a discrete time period thereafter, prior to complete neurologic maturation. As such, these observations fulfill a criterion of utmost importance in the search for etiologic significance in the Sudden Infant Death Syndrome, and, in a broad sense, support the concept of selective maturational failure as a possible cause for age-dependent, unexpected infant death.

Age Factors

The long tracheostomy tube. Alternative management of distal tracheal stenosis.

The incidence of tracheal strictures has greatly increased, and even in the most controlled clinical setting, the treatment of this problem requires sophisticated surgical management. We present an alternative method of management that was initially used to secure a temporary airway in young and debilitated patients. This technique has provided both immediate relief of the airway obstruction and definitive long-term correction of the stenosis, with a low complication rate.

Adult

Tracheostomy decannulation.

Tracheostomy in pediatric patients involves major morbidity that is often reflected in prolonged decannulation difficulty. A review of 123 consecutive pediatric tracheostomies shows that 44 patients experienced such difficulties. Among those patients suffering decannulation delay, subglottic stenosis had developed in 39%, tracheal granuloma in 25%, fused cords in 11%, and temporary laryngeal abductor failure in 25%. Although the overall incidence of decannulation failure is high, more than 60% of those patients affected respond to treatment when diagnosis is prompt and accurate. In this regard, the laryngologist may play a central role in the management of the pediatric decannulation process.

Airway Obstruction