The future of laryngology.
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Forecasting↗
Biomedical subjects
R H Ossoff
Publications and source records attributed to R H Ossoff.
Regression of laryngeal dysplasia after serial microflap excision.
There is no consensus on the ideal management of premalignant lesions of the larynx. Published reports describe the use of mucosal stripping, microsurgical techniques, CO2 laser excision and ablation, and even conservation laryngeal surgery and radiotherapy. We performed a retrospective evaluation of 43 men and 11 women who underwent serial excision of dysplastic lesions with the microflap technique between 1990 and 2001. The average age of the patients was 57.2 years; 64% had a history of cigarette smoking, and 46% a history of alcohol consumption. The lesions were located on the middle part of the left vocal fold in 65% and on the mid-portion of the right vocal fold in 66%. The patients were followed for an average of 4.4 years. Of the 20 patients with severe dysplasia or carcinoma in situ treated with the microflap technique, only 1 progressed to invasive disease. Overall, there was a reduction in the severity of dysplasia after each procedure (p = .0008). The microflap technique reliably reduced the severity of dysplastic lesions of the vocal fold and was effective in local disease control.
Carcinoma in Situ↗
Phonomicrosurgery II: surgical techniques.
Optimal vocal outcome is the major goal of treatment of benign non-neoplastic vocal fold lesions. Current phonomicrosurgery techniques are based on a complete understanding of vocal fold anatomy and the physiology of vocal fold vibration. With the knowledge that these lesions typically involve the superficial layer of the lamina propria and not the overlying epithelium, dissection and excision should be limited to this layer. Vocal fold microflap techniques leave the overlying epithelium and the mucosal cover intact to minimize postoperative scarring and possible tethering to the underlying vocal ligament. Surgical excision is followed by a program of vocal rehabilitation.
Humans↗
Hoarseness.
The voice is the primary means of communication for humans socially and in the workplace. Although rarely life-threatening, voice problems cause tremendous alteration in daily living and should not be underestimated as a medical disorder. Besides affecting useful communication, voice problems may also signify the presence of more serious medical illnesses, such as malignancy or airway compromise. This article describes normal vocal anatomy and physiology and outlines a practical approach in evaluating patients with voice disorders.
Activities of Daily Living↗
Ablation of Teflon granulomas in the canine larynx with the free-electron laser.
This study develops a canine model for the treatment of laryngeal Teflon granulomas and demonstrates endoscopic ablation using the free-electron laser (FEL) set at a wavelength of 8.5 microm. Laryngeal Teflon granulomas may cause dysphonia and airway obstruction, and they are difficult to remove. The infrared absorption spectrum of Teflon reveals a strong absorption peak centered at 8.5 microm. In this study, 12 dogs had the right vocal cord injected with Teflon paste. Two months later, Teflon granuloma formation was confirmed histologically. Laser incisions into the granulomas were performed at 3 different wavelengths: 7.4 microm (FEL), 8.5 microm (FEL), and 10.6 microm (carbon dioxide laser). Histopathologic analysis was performed at 1 week and 6 weeks after the laser incisions. The FEL at the 8.5-microm wavelength was found to optimally ablate the Teflon granulomas, but the granulomas persisted in the specimens treated with 7.4 microm (FEL) and 10.6 microm (carbon dioxide laser).
Animals↗
Histologic study of oral mucosa wound healing: a comparison of a 6.0- to 6.8-micrometer pulsed laser and a carbon dioxide laser.
Incisional wound healing in the canine oral mucosa was histologically monitored at 3, 7, and 14 days after incision. Healing was compared from a scalpel, a carbon dioxide (CO2) laser at 10.6 microm, and the Vanderbilt free-electron laser tuned to 6.0, 6.45, and 6.8 microm. A significant delay in wound healing was observed when incisions were made with the CO2 laser, probably attributable to the excess thermal damage caused by the continuous-wave laser beam. When using the short pulsed, free-electron laser, a much smaller delay comparable to the scalpel wound healing was observed. This smaller delay tended to decrease with increasing tissue absorption. The results emphasize the greater importance of laser pulse duration rather than wavelength in relation to the subsequent wound healing.
Absorption↗
Effect of pulse duration on wound healing using a CO2 laser.
The authors investigated wound healing of incisions in the buccal mucosa of a canine model created using a CO2 laser with a short pulse structure (60 micros, 100 micros, and 120 micros) rather than a conventional continuous wave structure in a shuttered mode. The tissue from 10 animals was evaluated histologically and with tensiometry acutely and at postoperative days 3, 7, and 14. A Bonferroni-Dunn corrected ANOVA analysis at a 95% significance level was used to compare the effect of pulse duration on histologic morphology and wound tensile strength. The data indicate that shorter laser pulse durations create less lateral thermal injury (P < .009) and wounds with greater tensile strength (P < .005), resulting in earlier wound healing. The results also show that heat, sufficient to damage tissue, was conducted to adjacent tissue during laser pulses of 100 micros and longer. These results demonstrate that surgical CO2 lasers with a short pulse structure of approximately 60 micros or less could offer more prompt wound healing while maintaining the advantages of a 10.6-microm wavelength laser.
Animals↗
Laryngotracheal reconstruction in the adult: a ten year experience.
The purpose of this study is to retrospectively analyze our experience with airway reconstruction, to outline a new staging system for laryngotracheal (LT) stenosis, and to identify preoperatively those patients likely to fail reconstruction. We reviewed 41 patients who underwent 46 LT reconstructions over the past 10 years. Success was judged by the ability to decannulate patients within 1 year postoperatively. Of our patients, 63% were treated successfully, and an additional 17% had intermediate success. The techniques used for laryngotracheoplasty with augmentation grafting and tracheal resection are reviewed. Major complications, thoracic complications, and wound complications are presented. Each patient was staged by the McCaffrey staging system and Cotton grades. We propose a new staging system based on the extent of the stenosis throughout the glottis, subglottis, and trachea. It is logical and easy to use. Applied to our cases of LT stenosis retrospectively, the new system predicts clinical success (chi2, p = .05). Using contingency tables and chi2 testing for statistical evaluation, we found that diabetics have a significantly higher failure rate (chi2, p = .0002). Further, we identified a group of patients who in addition to the airway stenosis also had comorbid medical conditions that frequently necessitate a tracheostomy. These patients have a significantly higher failure rate (chi2, p = .009). Using this information and applying the staging system prior to reconstruction, we can identify patients likely to fail.
Adolescent↗
Ablation of teflon granuloma with the free-electron laser emitting in the eight- to nine-micron range.
In this study, we developed a rat model for Teflon granuloma and used this model to evaluate the removal of the granuloma at laser wavelengths at which Teflon has a maximal absorption. Twenty-four Teflon granulomas were created in 12 rats, and the gross and histologic effects from laser incision at four different wavelengths (8.25, 8.5, 8.75, and 10.6 microm) were evaluated acutely and at 7 and 14 days postoperatively. Polytetrafluoroethylene, or Teflon, is a relatively inert substance that has been used over the past 4 decades for endoscopic injection into the thyroarytenoid muscle of the larynx for the purposes of laryngeal rehabilitation in cases of unilateral vocal fold paralysis or incomplete glottic closure. In certain cases in which formation of granulomatous reaction to the Teflon occurs, patients may have significant dysphonia or airway compromise. Once Teflon has infiltrated the surrounding tissue planes, it is exceedingly difficult to remove endoscopically. Endoscopic removal of this granuloma is usually attempted with the carbon dioxide (CO2) laser and has had limited success. Examination of the infrared absorption spectrum of polytetrafluoroethylene reveals strong absorption in the mid-infrared region in the 8- to 9-microm range, with minimal absorption at 10.6 microm. Therefore, this absorption spectrum predicts a more efficient vaporization of Teflon at wavelengths near 8.5 microm. Using the free-electron laser to generate 8.25-, 8.5-, and 8.75-microm laser light, we found Teflon granuloma ablation was far superior to CO2 laser ablation at 10.6 microm. The 8.25-, 8.5-, and 8.75-microm wavelengths selectively ablated Teflon granuloma with minimal to no collateral thermal injury to tissue. The differences in thermal effects observed while actually using the lasers were confirmed histologically.
Animals↗
Microvascular lesions of the true vocal fold.
Microvascular lesions, also called varices or capillary ectasias, in contrast to vocal fold polyps with telangiectatic vessels, are relatively small lesions arising from the microcirculation of the vocal fold. Varices are most commonly seen in female professional vocalists and may be secondary to repetitive trauma, hormonal variations, or repeated inflammation. Microvascular lesions may either be asymptomatic or cause frank dysphonia by interrupting the normal vibratory pattern, mass, or closure of the vocal folds. They may also lead to vocal fold hemorrhage, scarring, or polyp formation. Laryngovideostroboscopy is the key in determining the functional significance of vocal fold varices. Management of patients with a varix includes medical therapy, speech therapy, and occasionally surgical vaporization. Indications for surgery are recurrent hemorrhage, enlargement of the varix, development of a mass in conjunction with the varix or hemorrhage, and unacceptable dysphonia after maximal medical and speech therapy due to a functionally significant varix.
Adult↗
Lateral laryngotomy for the removal of Teflon granuloma.
Teflon injection has been used for vocal fold medialization following paralysis. Recently, numerous articles have discussed the complications of Teflon injection, including overinjection, airway obstruction. Teflon granuloma, and an abnormal mass effect creating a decreased vibratory character of the true vocal fold. Multiple techniques for Teflon removal have been described. This report details our experience with complete Teflon granuloma removal via a lateral laryngotomy under local anesthesia. Microscopic dissection of the entire granuloma and the paraglottic space was accomplished in all patients. Due to extensive destruction caused by the granuloma, the vocal ligament was resected in 3 patients; it was partially resected and reanastomosed in 1 case, and spared in 6 patients. Laryngeal reconstruction was accomplished with an inferiorly based sternohyoid muscle rotation flap and arytenoid adduction. Effortful speech secondary to pressed vocal quality resolved in all patients. Near-normal to normal vocal quality was obtained in 4 patients, with the average "voice desirability" improving 60% and the effective glottic width increasing 29%. Factors that contributed to a successful outcome included noninvolvement of the vocal ligament and sparing of the mucosal cover.
Adult↗
Posterior glottic stenosis: a canine model.
Posterior glottic stenosis is a disabling disease in which the vocal folds are fixed near the midline. This allows adequate vocal fold adduction for voicing, but does not permit useful abduction for ventilation. The most common cause is prolonged endotracheal intubation for mechanical ventilation, and the incidence is estimated at 4% for intubations between 5 and 10 days. Currently, our understanding and treatment modalities are based on retrospective reviews of small, nonrandomized clinical experiences. The purpose of this project was to develop an animal model that would improve our understanding of histologic changes and allow future prospective randomized trials for therapeutic intervention. Twelve dogs, 15 to 25 kg, were randomly divided into three groups. Animals in group I had a superficial injury produced in the tissue over the right cricoarytenoid joint; animals in group 2 had a deep soft tissue injury produced; and animals in group 3 underwent joint opening. The animals were allowed to recover for 2 months. Morphometric analysis of the harvested larynges demonstrated clinically significant limitation in motion in the animals with deep soft tissue injury and in animals with joint disruption. Histologic analysis revealed various degrees of injury, from loss of subepithelial soft tissue to cartilaginous resorption and fusion of the arytenoid to the cricoid. These findings were directly related to the depth of the initial injury. It is possible to produce posterior glottic stenosis in the canine species. This will serve as a reliable animal model for future study.
Animals↗
Patterns of care for cancer of the larynx in the United States.
OBJECTIVE: To assess case-mix characteristics, treatment patterns, and outcomes for laryngeal cancer using the largest series of patients to date. DESIGN: Analyses performed on retrospectively collected survey data submitted by hospitals for diagnostic periods 1980 through 1985 and 1990 through 1992 (with a 9-year follow-up for the long-term group). SETTING: Broad spectrum of US hospitals (N = 769). PATIENTS: Consecutively accrued series of patients with laryngeal cancer (N = 16,936), with only squamous cell carcinomas (N = 16,213) analyzed. INTERVENTIONS: Surgery, radiation therapy, and chemotherapy. MAIN OUTCOME MEASURES: Descriptive analyses of case-mix, diagnostic, and treatment characteristics plus recurrence and 5-year, disease-specific survival outcomes. RESULTS: There was a slight increase across these years in stage IV disease and in radiation therapy (with or without surgery and/or chemotherapy). Overall diversity of management of this disease (by site and stage) was apparent. Five-year survival rates indicated a large difference between modified groupings of the T and N classifications, separating stages III and IV cases into localized disease (87.5% for T1-T2; 76.0% for T3-T4 cases) and regional metastasis (46.2%). CONCLUSIONS: Regardless of improvements in entering data in hospital records (most commendably, staging), more rigorous standards are needed. Also, the small increase in advanced-stage patients indicates that efforts toward early detection have not been successful. The rise in radiation therapy perhaps reflected an increased use of nonsurgical treatment for early-stage patients and organ-sparing radiochemotherapy protocols for advanced-stage patients. Regrouping stages III and IV cases into localized disease vs regional metastasis appears to predict survival better. Ongoing refinements of the American Joint Committee on Cancer staging scheme will hopefully improve this cancer's classification.
Carcinoma, Squamous Cell↗
Healing of laser incisions in rat dermis: comparisons of the carbon dioxide laser under manual and computer control and the scalpel.
BACKGROUND AND OBJECTIVE: The Computer-Assisted Surgical Techniques (CAST) program was researched to decrease lateral tissue damage and improve wound healing subsequent to laser incision. CAST differs from the traditional laser because it makes the incision in a discontinuous manner, allowing tissue to cool during the incision process. STUDY DESIGN/MATERIAL AND METHODS: The transient temperature changes in the tissue adjacent to the incision were measured with a thermocouple in a rat model. The subsequent wound healing was studied with histology and tensiometry. RESULTS: The thermal measurements demonstrated that all CAST settings were cooler than the continuous mode of laser incision. However, histology and tensiometric studies showed mixed results. CONCLUSION: This research demonstrates that CAST can be used in future surgical applications with no delay in wound healing as compared to the manually controlled laser. However, this study also finds no decrease in the wound healing time when using the CAST program.
Animals↗
Precise laser incisions, corrected for patient respiration with an intelligent aiming system.
BACKGROUND AND OBJECTIVE: Patient motion due to respiration and blood flow can negatively affect the precision of a laser incision. STUDY DESIGN/MATERIALS AND METHODS: The video image of the surgical field is monitored by a computer system, and trends in the motion are "learned" by the computer. The laser beam is then adjusted to compensate for predicted motion. Occasional erratic motion sometime causes a false prediction. In this event, the prediction is corrected with real-time feedback. RESULTS: Our experience shows that even with occasional false predictions, the motion compensation still gives a better incision. The surgeon always maintains control of the laser. The net effect of the intelligent aiming system is to subtract away nearly all patient motions. CONCLUSION: Laser surgery can be performed with greater accuracy and reduced unwanted tissue damage with the predictive tracking of motion.
Computer Simulation↗
Medial microflap for excision of benign vocal fold lesions.
The goal of microlaryngeal surgery is to treat the pathology while preserving or improving vocal function. The medial microflap technique was thus developed. An incision is made over or abutting the lesion, which is then dissected from the vocal ligament and overlying mucosa. Seventeen patients underwent medial microflap excision of their lesions. Postoperative videostroboscopic examinations revealed the presence of mucosal wave and improved glottic closure in 15 of the 17 patients. Acoustic and perceptual analyses revealed improved voice quality. The medial technique is a modification of the previously described lateral microflap technique. Patients whose stroboscopic examination implies lack of involvement of the vocal ligament are candidates for this technique. By identifying normal histologic planes without extensive dissection, lesions can be excised with minimal interruption of vibratory mechanics.
Dissection↗
Hypopharyngeal cancer patient care evaluation.
A survey was conducted to identify demographics and standards of care for treatment of hypopharyngeal squamous cell carcinoma in the United States. Data were accrued from voluntary submission of cancer registry and medical chart information from 769 hospitals representing 2939 cases diagnosed from 1980 to 1985 and 1990 to 1992. Clinical findings, diagnostic procedures employed, treatment practices, and outcome are presented. Overall, 5-year disease-specific survival was 33.4%, which segregated to 63.1% (stage I), 57.5% (stage II), 41.8% (stage III), and 22% (stage IV). Survival was best for patients treated with surgery only (50.4%), similar with combined surgery and irradiation (48%), and worse with irradiation only (25.8%). This analysis provides a standard to which current treatment practice and future clinical trials may be compared.
Aged↗
Speech outcomes after laryngeal cancer management.
As our ability to treat laryngeal cancer and prolong the lives of our patients improves, we must place increasing importance on maintaining the best voice possible in every case. Treatment options for laryngeal cancer continue to expand, and it is important that otolaryngologists stay well informed; not only concerning the local control and disease-free survival associated with each new treatment, but also the expected voice result. This article describes the voice and speech outcomes that are associated with various treatments for laryngeal cancer. In addition, comparisons of the expected voice results for different therapeutic modalities are examined.
Carcinoma, Squamous Cell↗