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Biomedical subjects

H H Dedo

Publications and source records attributed to H H Dedo.

At least 73 records · Page 4Linked to original sources

Rhabdomyosarcoma of the soft palate in three patients with follow-up of longer than ten years.

Rhabdomyosarcoma of the head and neck is a rare childhood neoplasm. Most occur in the orbit, which accounts for the scarcity of papers on modern techniques of treatment of soft palate rhabdomyosarcomas. Only 30 cases of soft palate rhabdomyosarcoma have been reported in recent years and none had long-term follow-up periods (greater than 10 yr). This study reports three cases of pediatric soft palate rhabdomyosarcomas treated with surgery, radiotherapy (two of three), and chemotherapy. The complications that occurred in one patient are discussed.

Child↗

Carotid-body-like tissue within the recurrent laryngeal nerve: an endoneural chemosensitive micro-organ?

Paraganglia associated with the ninth and tenth cranial nerves have been observed in several locations in the head and neck region. The most studied of these organs, both morphologically and functionally, is the carotid body, a chemoreceptor organ located in the carotid bifurcation. In the present study a microglomus (microparaganglion) composed of islands of carotid-body-like cells was found in the endoneural space of the recurrent laryngeal nerve of rats, 5 to 10 mm from the nerve entrance into the larynx. This microglomus was surrounded by bundles of myelinated and unmyelinated nerve fibers. Fenestrated blood vessels were observed between cells. The cells were characterized by their cytoplasmic membrane-bound granules and dense-core vesicles. Ultrastructurally, these cells seemed to be identical to carotid body chemoreceptor cells and thus to indicate that the cells of the microglomus store catecholamines. Nerve terminals impinging on the cells, classified as both afferent and efferent, were also identified. The recurrent laryngeal endoneural microglomus may have a chemosensitive function influencing the laryngeal physiologic reflex mechanisms.

Animals↗

Spastic dysphonia: a patient profile of 200 cases.

A comprehensive case history profile of spastic dysphonia patients was established, using 200 patients matched to 200 controls. The case histories and epidemiologic profiles for male and female patients revealed few dissimilarities. Likewise, intergroup (patients-controls) health history profiles differed in only a few specific instances. The data suggest non-psychogenic, non-behavioral causation of spastic dysphonia; however, neither a definitive cluster or clusters of events at onset nor any unequivocal epidemiologic factor was accountable for spastic dysphonia. Short of qualified improvement with voice therapy in some patients, no form of treatment other than recurrent laryngeal nerve section was shown to be of any significant help for the patient population sampled.

Adult↗

Preoperative embolization of juvenile angiofibromas of the nasopharynx.

The juvenile nasopharyngeal angiofibroma is a vascular tumor. Careful and complete removal is challenging because of the brisk bleeding during surgery. The means applied to reduce this blood loss have included preoperative estrogens, ligation of feeding vessels, silicone embolization of feeding vessels, and cryosurgery. We have used preoperative Gelfoam embolization of the internal maxillary artery in seven patients. Our clinical impression of significant reduction in loss of blood was confirmed by comparison with 16 previous patients. The average amount of blood lost in the embolized group was half that of the control group. A study of this type comprises many variables; however, the results do suggest that preoperative embolization of the internal maxillary artery is of advantage in the surgical treatment of juvenile angiofibromas.

Adolescent↗

Recurrent laryngeal nerve section for spastic dysphonia.

Spastic dysphonia is a severe vocal disability in which a person speaks with excessively adducted vocal cords. The resulting weak phonation sounds tight, as if he were being strangled, and has also been descrived as laryngeal stutter. It is often accompanied by face and neck grimaces. In the past it has been regarded as psychoneurotic in orgin and treated with speech therapy and psychotherapy with disappointing results. Because of laboratory and clinical observation that recurrent nerve paralysis retracts the involved vocal cord from the midline, it was proposed that deliberate section of the recurrent nerve would improve the vocal quality of patients with spastic dysphonia. In 34 patients the recurrent nerve was sectioned after Xylocaine temporary paralysis showed significant improvement in vocal quality. Several patients have been advised against this operation because of the type of voice they developed with one vocal cord temporarily paralyzed. With nerve section plus postoperative speech therapy, approximately half of the patients have returned close to a "normal" but soft phonatory voice. The rest had varying degrees of improvement, but all, so far, have been pleased with the improvement in ease and quality of phonation and reduction or elimination of face and neck grimaces. Two men have a breathy component in their phonatroy voices, and one woman has variable pitch.

Adult↗

Recurrent laryngeal nerve histopathology in spastic dysphonia: a preliminary study.

Spastic dysphonia is a severe voice disorder ordinarily described as psychogenic. Organic-neurologic changes secondary to central or peripheral nervous system involvement have also been postulated and led recently to the surgical treatment of spastic dysphonia by unilateral section of the recurrent laryngeal nerve (RLN). This study reports the histologic findings from these resections of the RLN from patients with an average 9.5 years duration of spastic dysphonia. Thirty percent of the RLNs examined demonstrated significant abnormalities as compared to age-matched controls. Although no reactive changes were noted by light microscopy, groups of fibers which did not stain for myelin or axons were found in RLNs from patients with spastic dysphonia. A preliminary ultrastructural study of these areas in one RLN revealed sheets of unmyelinated axons. These findings suggest an organic basis for spastic dysphonia at least in some patients.

Adult↗

Endoscopic Teflon keel for anterior glottic web.

Anterior glottic webs are generally repaired with a McNaught keel placed and removed by laryngofissure. Attempts have been made since 1922 to repair these webs endoscopically. An endoscopic technique using a Teflon keel which has been successful in properly selected cases is presented.

Adult↗

Laryngeal papilloma: results of treatment with the CO2 laser and podophyllum.

From 1976 to 1982, 109 patients with recurrent laryngeal papillomas were treated with a total of 548 CO2 laser excisions followed by podophyllum painting. There was high incidence of multiple sites of involvement, especially the tracheobronchial tree (18.3%) and palate (8.3%). Four patients had pulmonary parenchymal involvement. Patients were treated at 2-month intervals until they entered remission. Thereafter, microdirect laryngoscopies were advised at longer intervals. Remission was achieved in 41%; it occurred at all ages although it was most common during adolescence and rarest in the very young and very old. Many patients obtained remission with the CO2 laser after multiple prior cup forceps removals had not achieved remission. Only two tracheotomies (1.8%) were required and no deaths occurred. When compared with mechanical methods of papilloma removal, CO2 laser excision with podophyllum painting represents a clear advance in terms of preservation of laryngeal physiology and avoidance of life-threatening complications.

Adolescent↗

Evaluation and treatment of recurrent spasticity after recurrent laryngeal nerve section. A preliminary report.

Of 365 spastic dysphonia patients treated by recurrent laryngeal nerve (RLN) section to date, 44 (12%) have experienced recurrence of the spastic dysphonia. Most of these 44 patients had moderately severe to very severe spastic dysphonia before the RLN section was performed. We believe, therefore, that preoperative severity is an important predictor of the likelihood of recurrence. Twenty-eight patients with recurrent spastic dysphonia following RLN section were further treated by one or more carbon dioxide laser thinnings of the paralyzed vocal fold. Following this procedure, 23 patients (50%) achieved eradication of spasticity, while a mild degree of spasticity remained in 17 (39%). These findings lead us to conclude that even though spastic dysphonia may recur following RLN section, a viable secondary surgical procedure is available.

Humans↗

Carbon dioxide laser resection of superficial oral carcinoma: indications, technique, and results.

A retrospective medical record review was done of 51 consecutive patients with 56 biopsy-proven squamous cell carcinomas of the oral cavity and oropharynx treated for cure by one of the authors (H.H.D.) using the carbon dioxide laser via microdirect pharyngoscopy. All 51 patients were followed for at least 3 years unless they died, and 27 were followed for 5 years. The tumors treated were superficial, accessible lesions without bone involvement or clinically apparent metastases. Eighteen patients had had irradiation or surgery at the same site, so were having salvage CO2 laser surgery. Indications and technique are discussed. Local recurrence and disease control rates were comparable to those of conventional local surgical excision at 3 and 5 years. Complication rate was low. Carbon dioxide laser resection with microscopic control is, we propose, an excellent modality for transoral excision of carefully selected lesions, and it offers increased precision, better visualization, minimal bleeding, and decreased postoperative morbidity compared to other surgical techniques.

Carbon Dioxide↗

Current evidence for the organic etiology of spastic dysphonia.

For over 100 years it has been universally assumed in the literature that spastic dysphonia is a functional or psychoneurotic voice disorder. In the last few years, new data have accumulated that support the concept that spastic dysphonia is caused by an organic, rather than a functional, abnormality. Histologic examination of segments of the recurrent laryngeal nerve removed from patients with spastic dysphonia has revealed myelin abnormalities in 30% of the nerves examined. Neurologic examination indicated brain stem or basal ganglia disturbances in some patients who had no apparent nerve disease.

Axons↗

Predicting postoperative voice characteristics of spastic dysphonia patients.

Current treatment of spastic dysphonia may involve unilateral RLN section preceded by a temporary chemical paralysis of one RLN as a diagnostic test. This study compared the immediate postchemical paralysis and postsurgical paralysis voice and speech qualities of 33 spastic dysphonic patients using perceptual, acoustic, and temporal measurements and found that following section of the RLN, there was a decrease in overpressure and aperiodicity, an increase in vocal range, and a reduction of breathiness. Vocal tremor and speech rate were variably affected. It appears that chemical paralysis of the RLN is a fairly accurate means of previewing the postsurgical voice.

Female↗

Postoperative and follow-up studies of spastic dysphonia patients treated by recurrent laryngeal nerve section.

Long-term results of surgical treatment of spastic dysphonia by RLN section are evaluated by means of perceptual psychophysical scaling and by the patients themselves. It is found that a significant reduction in spastic dysphonia symptoms occurs as a result of surgery, and that these results are maintained after long-term follow-up in the majority of patients. These experimental observations are in agreement with the subjective assessment of postsurgical communication by the patients involved in the study.

Female↗