Desenvolvimento de protótipo para aplicação do laser de CO2 na laringe humana a curtas distâncias
Introduction: Laser endolaryngeal surgery has been performed with 350 and 400mm focal length (f ) lenses which converge the laser beam to a minimum spot size, called beam waist. The beam waist size can be described as: 2omega0 =lambdaf /pw², where lambda is the CO2 wavelength and 2omega is the beam...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2002 |
| País: | Brasil |
| Institución: | Universidade Federal de São Paulo (UNIFESP) |
| Repositorio: | Repositório Institucional da UNIFESP |
| Idioma: | portugués |
| OAI Identifier: | oai:repositorio.unifesp.br:11600/1370 |
| Acceso en línea: | http://dx.doi.org/10.1590/S0034-72992002000200008 http://repositorio.unifesp.br/handle/11600/1370 |
| Access Level: | acceso abierto |
| Palabra clave: | laryngoscopy endoscopic surgery laser larynx laringoscopia microcirurgia laringe |
| Sumario: | Introduction: Laser endolaryngeal surgery has been performed with 350 and 400mm focal length (f ) lenses which converge the laser beam to a minimum spot size, called beam waist. The beam waist size can be described as: 2omega0 =lambdaf /pw², where lambda is the CO2 wavelength and 2omega is the beam diameter. We developed an optical system which produces a very small beam waist. This small shaft of laser is delivered precisely on the target resulting in a reduced impact spot size enhancing precision and lessening surrounding tissue trauma on laryngeal surgery. Aim: To present an optical system which delivers the laser beam at a small distance from the human glottis. Study design: Clinical trial. Material and Methods: The manufactured prototype has two metallic cylindrical shafts joined in a 135º angle from the horizontal. A coated mirror positioned in its joint change the ray path in the same angle. Two coated lenses converge the laser to a calculated beam waist. The hand piece was coupled to the laser articulated arm and the system was set to 0.5 - 2.0 W at 0.05 sec. exposure time. Laryngeal exposure was achieved with the angled videolaryngoscopy. Three patients with vocal fold polyp underwent laser surgery with the technique above described. Results: A beam waist ranging from 200 to 250 mum was obtained (lambdaCO2 = 10,6 mum). The technique offered adequate laryngeal exposure and satisfactory image quality for a proper laser application. No technical difficulties nor major bleeding or mucosal charring was observed during the treatment. No excessive scarring was observed in a two-month follow-up laryngoscopy. Conclusion: The developed prototype produced very small laser shafts which are useful in the treatment of vocal fold polyps. |
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