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- ItemSomente MetadadadosAngled endoscopic laryngeal surgery: A new technique for diagnosis, surgery, and CO2 laser application(Lippincott Williams & Wilkins, 2002-06-01) Morgado, P. F.; Pontes, PAL; Universidade Federal de São Paulo (UNIFESP)Objective: To present the development and application of a new technique to perform cold and laser laryngeal surgery. Study Design: A prospective study of 11 patients submitted for endoscopic laryngeal surgery. Methods: the technique used an endoscope with a 45degrees upward curve of its distal end; a set of angled instruments including an intraoral retractor, scissors, and forceps; and a surgical CO2 laser microtip. Eleven patients with laryngeal diseases and an indication for microsurgery underwent angled endoscopic laryngeal surgery successfully. Four patients underwent laser surgery. the CO2 laser was set between 0.5 and 2.0 W at normal exposure times and delivered distally through a lens composition within the angled handpiece. Results: the lesions were precisely treated with minimal bleeding. the excised areas healed promptly, and no excessive scarring from laser application has been observed in a 5-month postoperative video laryngoscopy follow-up. No major morbidity and no worsening of the voice occurred in any of the patients. A wide-angle view with a greater depth of field than the surgical microscope and a three-dimensional view were obtained as a result of the use of an endoscope in this technique; visualization of undersurfaces and an unobstructed visual field have been a result of the endoscope use as well. A beam waist ranging between 200 and 350 mum was produced. Conclusions: the approach described in the present study may help the laryngologist overcome some of the shortcomings and difficulties in laryngeal surgery, especially when dealing with patients in whom adverse anatomy and certain clinical conditions contraindicate microlaryngoscopy. Because of a delivery of laser waves at shorter distances from the lesions, a more precise tissue exeresis with minimal disturbances to the vocal folds might be accomplished as a result of the smaller beam waist produced. Distal delivery of laser waves also reduces the risks of stray laser beam striking nontargeted areas. Long-term studies with a larger number of patients are necessary.
- ItemAcesso aberto (Open Access)Desenvolvimento de protótipo para aplicação do laser de CO2 na laringe humana a curtas distâncias(ABORL-CCF Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial, 2002-03-01) Morgado, Plínio F. [UNIFESP]; Wagner, Paulo [UNIFESP]; Neves, Luciano R. [UNIFESP]; Pontes, Paulo A. De L. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)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.
- ItemSomente MetadadadosEffects of Low-Level Laser Therapy on Collagen Expression and Neutrophil Infiltrate in 5-Fluorouracil-Induced Oral Mucositis in Hamsters(Wiley-Blackwell, 2010-08-01) Fontana Lopes, Nilza Nelly [UNIFESP]; Plapler, Helio [UNIFESP]; Lalla, Rajesh V.; Chavantes, Maria Cristina; Yoshimura, Elisabeth Mateus; Bastos da Silva, Marco Antonio [UNIFESP]; Seixas Alves, Maria Teresa [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Univ Connecticut; Universidade de São Paulo (USP)Background and Objectives: Several studies have suggested that low-level laser therapy (LLLT) can ameliorate oral mucositis, however, the mechanisms involved are not well understood. the aim of this study was to investigate the mechanisms of action of LLLT on chemotherapy-induced oral mucositis, as related to effects on collagen expression and inflammationMaterials and Methods: A hamster cheek pouch model of oral mucositis was used with all animals receiving intraperitoneal 5-fluorouracil, followed by surface irritation. Animals were randomly allocated into three groups, and treated with an InGaAIP diode laser at a wavelength of 660 nm and output power of 35 or 100 mW laser, or no laser Clinical severity of mucositis was assessed at four time-points by a blinded examiner Buccal pouch tissue was harvested from a subgroup of animals in each group at four time-points. Collagen was qualitatively and quantitatively evaluated after picrosinus staining. the density of the neutrophil infiltrate was also scoredResults: Peak clinical severity of mucositis was reduced in the 35 mW laser group as compared to the 100 mW and control groups the reduced peak clinical severity of mucositis in the 35 mW laser group was accompanied by a decrease in the number of neutrophils and an increase in the proportion of mature collagen as compared to the other two groups. the total quantity of collagen was significantly higher in the control (no laser) group at the day 11 time-point, as compared to the 35 mW laser group, consistent with a more prolonged inflammatory response in the control group.Conclusion: This study supports two mechanisms of action for LLLT in reducing mucositis severity. the increase in collagen organization in response to the 35 mW laser indicates that LLLT promotes wound healing in addition, LLLT also appears to have an anti-inflammatory effect, as evidenced by the reduction in neutrophil infiltrate Lasers Surg Med 42 546-552, 2010. (C) 2010 Wiley-Liss, Inc.
- ItemAcesso aberto (Open Access)Fotodesbridamento de válvulas aórticas calcificadas com laser de CO2(Sociedade Brasileira de Cirurgia Cardiovascular, 1987-08-01) Gomes, Walter José [UNIFESP]; Goldenberg, Saul [UNIFESP]; Buffolo, Enio [UNIFESP]; Gomes, Walter José [UNIFESP]; Goldenberg, Saul [UNIFESP]; Buffolo, Enio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)The authors present 6 cases of calcified aortic valves, removed from patients during aortic valve replacement, which underwent photodebridement with CO2 laser. Radiographic, photografic weight and histopathological studies have shown extensive debridement, and the valves showing improved morphology and function. The advantages of the procedure made concerning valve replacement and clinical application is foreseen for the method.
- ItemSomente MetadadadosThe impact of pulse duration and burn grade on size of retinal photocoagulation lesion: implications for pattern density(Lippincott Williams & Wilkins, 2011-09-01) Palanker, Daniel; Lavinsky, Daniel [UNIFESP]; Blumenkranz, Mark Scott; Marcellino, George; Stanford Univ; Universidade Federal de São Paulo (UNIFESP); OptiMedica CorpPurpose: Shorter pulses used in pattern scanning photocoagulation (10-20 milliseconds [ms]) tend to produce lighter and smaller lesions than the Early Treatment Diabetic Retinopathy Study standard 100-ms exposures. Smaller lesions result in fewer complications but may potentially reduce clinical efficacy. It is worthwhile to reevaluate existing standards for the number and size of lesions needed.Methods: The width of the coagulated zone in patients undergoing retinal photocoagulation was measured using optical coherence tomography. Lesions of moderate, light, and barely visible clinical grades were compared for 100, 200, and 400 mu m spot sizes and pulse durations of 20 ms and 100 ms.Results: To maintain the same total area as in 1,000 standard burns (100 ms, moderate) with a 400-mu m beam, a larger number of 20-ms lesions are required: 1,464, 1,979, and 3,520 for moderate, light, and barely visible grades, respectively. Because of stronger relative effect of heat diffusion with a smaller beam, with 200 mu m this ratio increases: 1,932, 2,783, and 5,017 lesions of 20 ms with moderate, light, and barely visible grades correspond to the area of 1,000 standard burns.Conclusion: A simple formula is derived for calculation of the required spot spacing in the laser pattern for panretinal photocoagulation with various laser parameters to maintain the same total coagulated area. RETINA 31: 1664-1669, 2011
- ItemSomente MetadadadosIntravitreal bevacizumab for exudative age-related macular degeneration after multiple treatments(Springer, 2007-02-01) Aggio, Fabio Bom [UNIFESP]; Farah, Michel Eid; Silva, Wagner Camilo; Melo, Gustavo Barreto; Universidade Federal de São Paulo (UNIFESP)Photodynamic therapy with verteporfin (PDT) significantly reduces the risk of vision loss in patients with exudative age-related macular degeneration (AMD). Indocyanine green-mediated photothrombosis (IMP) and transpupillary thermotherapy (TTT) may also be beneficial for selective cases of exudative AMD. However, a substantial subset of patients responds poorly to these treatments. Intravitreal bevacizumab (IVB) has been recently used in the treatment of exudative AMD, showing both visual and anatomic improvement in the majority of cases.This interventional retrospective case series reports the effects of IVB in 17 eyes with subfoveal neovascular AMD that had undergone repeated PDT (combined or not with triamcinolone acetonide) or PDT followed by either IMP or TTT with poor results. the main outcome measures were visual acuity and tomographic signs of intra/subretinal fluid, as well as central retinal thickness.Most patients received a single IVB injection. the mean follow-up was 4.47 months. the mean logMAR visual acuity changed from 1.17 +/- 0.40 to 1.06 +/- 0.44 (P=0.17). the mean central retinal thickness decreased from 404.05 +/- 245.26 to 280.23 +/- 143.14 mu m (P=0.032). At the end of the study, lack of tomographic signs of intra/subretinal fluid was noted in four (23.5%) eyes. No ocular or systemic side effects were identified.Short-term results with IVB for the treatment of exudative AMD have been promising. However, the chronic retinal and pigment epithelium changes frequently present in eyes that underwent multiple previous treatments may limit complete visual recovery. To our knowledge, this is the first report on the use of IVB for this particular group of AMD patients.
- ItemAcesso aberto (Open Access)Laryngeal sequelae of recurrent respiratory papillomatosis surgery in children(Associação Médica Brasileira, 2012-04-01) Hermann, Juliana Sato [UNIFESP]; Pontes, Paulo [UNIFESP]; Weckx, Luc Louis Maurice [UNIFESP]; Fujita, Reginaldo Raimundo [UNIFESP]; Avelino, Melissa Ameloti Gomes [UNIFESP]; Pignatari, Shirley Shizue Nagata [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)OBJECTIVE: To evaluate laryngeal sequelae from surgical treatment of recurrent respiratory papillomatosis in children, as well as associated risk factors. METHODS: Case-control study. Medical record data analysis of 50 children with recurrent respiratory papillomatosis, divided into two groups: with and without laryngeal sequelae. The group of patients with laryngeal sequelae was compared to those without sequelae in regard to the onset of disease, age at first surgery, number and frequency of surgeries, disease stage, and type of surgery (CO2 laser, cold forceps). RESULTS: 23 patients (46%) sustained laryngeal sequelae. The most frequent sequela was anterior commissure synechia (17 patients [34%]), followed by glottic stenosis (six patients [12%]). There was no statistically significant difference between groups with and without laryngeal sequelae regarding the disease onset (p = 0.93), age at first surgery (p = 0.68), number of surgeries (p = 0.22), annual frequency of surgery (p = 0.93), presence of papilloma in anterior (p = 0.430) or posterior commissure (p = 0.39), and type of surgery (p = 0.27). The Derkay anatomical score (a staging system that assesses the extent of the disease in the aerodigestive tract) was significantly higher in the laryngeal sequelae group (p = 0.04). CONCLUSION: Laryngeal sequelae are a frequent complication of recurrent respiratory papillomatosis surgical treatment in children, particularly anterior commissure synechiae and glottic stenosis. Advanced stages are associated with increased risk of laryngeal sequelae after surgery.
- ItemSomente MetadadadosA simple method to synthesize silver nanoparticles by photo-reduction(Elsevier B.V., 2007-09-15) Courrol, Lilia Coronato; Silva, Flavia Rodrigues de Oliveira; Gomes, Laercio; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP); IPENIn this work, a photo-induced method for obtaining silver nanoparticles (SNPs) was investigated using UV LED, xenon lamp and sodium lamp excitation. Silver colloidal solutions were prepared using autopolymerizable resin and AgNO3 in an ethanol solution. This study shows that the combination of pulsed laser ablation in liquids with previous UV-visible illumination provides a simple, applicable and flexible technique for the fabrication of nanoparticles of 5-8 nm in size. (c) 2007 Elsevier B.V. All rights reserved.
- ItemSomente MetadadadosStudy of color centers produced in thulium doped YLF crystals irradiated by electron beam and femtosecond laser pulses(Elsevier B.V., 2007-02-15) Courrol, Lilia C.; Ranieri, Izilda M.; Baldochi, Sonia Licia; Samad, Ricardo E.; Freitas, Anderson Z. de; Gomes, Laercio; Vieira, Nilson D.; Universidade Federal de São Paulo (UNIFESP); IPENIn this work, we report the influence of the presence of photochromic and color centers in the photobleaching of thulium ions blue emission in YLF (YLiF4) crystals doped with 1 mol% Tm (3+). the samples were irradiated at room temperature both with electron beam and high intensity ultrashort pulses from a Ti:Sapphire CPA laser system. in both irradiations the production of photochromic and color centers was observed via the absorption bands in the UV and visible ranges. Pure LiF and pure and oxygen doped YLF crystals were used to identify the color centers produced and their optical properties. From a phenomenological model it was possible to study the interaction between color centers and thulium ions, and their effect in photobleaching and photodarkening behaviors. Finally, the blue up laser level population was computed using a rate equation analysis. (c) 2006 Elsevier B.V. All rights reserved.