Thesis (M Social Work(Social Work))--University of Stellenbosch,2009. / A laryngectomy is mostly indicated as treatment for an advanced stage of cancer of the larynx, during which the patient’s voice box is removed. This operation can hold major psycho-social implications for the patient and family. To cope with the challenges in daily life, patients need social support. A lack of available literature and research regarding the role of the social worker in facilitating support groups for these patients and families was identified and motivated this research study. The goal of the study was to gain a better understanding of the laryngectomy patient’s need for support groups in a hospital setting when attending the follow-up clinic at the hospital. A combination of both the exploratory and descriptive research designs together with a combination of mainly a qualitative and to a certain extent the quantitative research approaches, was used. From this, knowledge, insight and an understanding of the need for support groups in a hospital setting from a social work perspective were obtained. Permission to conduct the proposed study was granted by the Committee for Human Research at the University of Stellenbosch. The literature study first focused on medical aspects of a laryngectomy and social work intervention services within a hospital setting as part of the multi-disciplinary approach. Second, psycho-social effects of a laryngectomy from an ecological perspective were discussed, referring to the physical, social and psychological effects of surgery upon the patient and family. Third, support and aftercare were discussed with specific reference to the role of the social worker in offering social support to the patient and family. For the empirical study, twenty laryngectomy patients from the service area of Tygerberg Hospital were involved from January 2008 to May 2008. Criteria for inclusion in the study referred to patients who had their operation not less than three months previously, attended the support group during follow-up visits at the hospital and who had successfully acquired tragea-oesophageal speech. Based on the literature review, a semi-structured questionnaire and face-to-face interview were used as research instruments to overcome the limitation of illiteracy. The results of the investigation mainly confirmed the findings of the literature study namely that laryngectomy patients can benefit from support groups in order to address their need for social support in dealing with daily life challenges. Patients indicated that they mainly needed information regarding post-operative adaptation as this was where problems were mostly experienced. The majority of patients suggested the use of support groups in this regard. Focus was placed on an exploration and description of patients’ needs for such support groups. Benefits of support groups were found to be totally compatible with the role of the social worker. The results therefore gave an indication of social work intervention services and referred to: provision of information, problem-solving, offer of social and emotional support, and promotion of rehabilitation opportunities, thereby improving the patient’s quality of life. Recommendations were aimed at social work intervention services relating to support and aftercare offered to laryngectomy patients and relatives. Future research to develop social work programmes for health care professionals in order to effectively support these patients and their families was proposed. From practical experience of support groups a study regarding the role of pre- and primary schoolchildren or grandchildren in the rehabilitation of laryngectomy patients was also suggested.

Photodynamic therapy, PDT, is a method to diagnose and treat cancer. In PDT a sensitizer is administered to the patient and this sensitizer is accumulated in tumors. If the sensitizer-containing tumor is subjected to a laser of a specific wavelength the tumor is fluorescing allowing diagnostics. If other wavelengths are used a process involving reactive oxygen species and singlet oxygen is started and the tumor cells are killed. This process thus requires oxygen as well. This thesis investigates how UV-induced damage of the skin and different physiological factors of the skin influences the uptake of 5- aminolevulinic acid, ALA, and its conversion to the active sensitizer protoporphyrin IX, PpIX. It shows that UV-induced damage affects both the uptake and production of PpIX. UV-induced damage lowers the PpIX produced after ALA application both if the damage is acute and in chronically UV-affected skin. The PpIX production differs inter and intra individually. When looking how different physiological factors affect the PpIX production after topically applied ALA the thesis shows that an increase of temperature increases the production. No correlation between the formation of PpIX and the density of hair follicles was found and a weak correlation was seen comparing the epidermal and total dermal thickness and PpIX production The thesis also shows how PDT is used in treating laryngeal malignancies. It shows that it is possible to cure laryngeal tumors (both squamous cell carcinomas and sarcomas) using PDT primarily, and that the cure rate as well as outcome of voice and patient safety is comparable to the conventional treatment modalities. PDT can also be used as a function and organ sparing treatment for recurring laryngeal cancers, both squamous cell carcinomas and sarcomas.

Introdução: A movimentação das cartilagens aritenoides desempenha importante função tanto na abdução quanto na adução das pregas vocais e, consequentemente, na produção da voz normal. A assimetria destas cartilagens pode estar presente em algumas condições clínicas, como na paralisia unilateral de prega vocal ou na luxação / subluxação de articulação cricoaritenóidea. Há carência de estudos na literatura sobre o impacto que a assimetria de cartilagens aritenoides pode provocar no fechamento glótico e sobre a melhora que a aritenoidectomia parcial superomedial poder promover nesses casos de assimetria. Objetivo: O objetivo deste estudo foi analisar os efeitos que esta assimetria posicional de aritenoides pode desencadear no fechamento glótico posterior e avaliar o benefício que a aritenoidectomia parcial superomedial pode proporcionar a estes casos. Métodos: Realizou-se estudo experimental com 10 laringes humanas excisadas de cadáveres adultos, sendo 05 do sexo masculino e 05 do feminino. O fechamento glótico foi produzido com rotação das cartilagens aritenoides bilateralmente e a assimetria de aritenoides simulada com o uso de cola no interior de uma das articulações cricoaritenóideas com fixação da cartilagem aritenoide em posição anteromedial. Na aritenoidectomia parcial, removeu-se a porção superomedial da cartilagem submetida à assimetria. O fechamento glótico posterior foi avaliado com paquímetro digital para medir a distância entre os processos vocais antes e após a simulação da assimetria e da aritenoidectomia superomedial, para que as medidas fossem comparadas. Resultados: O fechamento glótico posterior de todas laringes estudadas passou de completo para incompleto após a simulação da assimetria posicional de aritenoides, sendo a distância média observada entre os processos vocais de 1,766mm (IC95%: 1,519-2,013). A aritenoidectomia superomedial realizada após a assimetria de aritenoides fez com que o fechamento glótico posterior voltasse de incompleto para completo em todas laringes da pesquisa. Conclusões: Os resultados da pesquisa sugerem que a assimetria posicional de cartilagens aritenoides parece comprometer o fechamento glótico posterior, aumentando a distância entre os processos vocais durante a adução das pregas vocais. Além disso, o estudo aponta que a aritenoidectomia superomedial pode melhorar o fechamento glótico posterior nestes casos de assimetria de aritenoides / Introduction: The movement of arytenoid cartilage plays an important role both in abduction and adduction of the vocal folds and, consequently, in the production of normal voice. The asymmetry of these cartilages may be present in some clinical conditions, such as in unilateral vocal fold paralysis or in the cricoarytenoid joint dislocation / subluxation. There is a lack of studies in the literature on the impact that the positional asymmetry of arytenoid cartilages can cause in the glottic closure and on the improvement that the superomedial partial arytenoidectomy can promote in these cases of asymmetry. Objective: The objective of this study was to analyze the effects that this arytenoid positional asymmetry can trigger in posterior glottic closure and to evaluate the benefit that superomedial partial arytenoidectomy can provide to these cases. Methods: An experimental study was carried out on 10 human larynx excised from adult cadavers, being 05 males and 05 females. Glottic closure was produced with rotation of the arytenoid cartilages bilaterally and the simulated arytenoid asymmetry with the use of glue inside one of the cricoarytenoid joints with anteromedial fixation of the arytenoid cartilage. In partial arytenoidectomy, the superomedial portion of the cartilage submitted to the asymmetry was removed. Posterior glottic closure was evaluated with a digital caliper to measure the distance between vocal processes before and after the simulation of asymmetry and superomedial arytenoidectomy, so that the measurements were compared. Results: The posterior glottic closure of all studied larynges went from complete to incomplete after the simulation of arytenoid positional asymmetry, with the mean distance observed between vocal processes of 1,766mm (95% CI: 1,519-2,013). Superomedial arytenoidectomy performed after arytenoid asymmetry caused the posterior glottic closure to return from incomplete to complete in all larynges of the study. Conclusions: The results of the research suggest that the positional asymmetry of arytenoid cartilages seems to compromise posterior glottic closure, increasing the distance between the vocal processes during vocal fold adduction. In addition, the study points out that superomedial partial arytenoidectomy may improve posterior glottic closure in these cases of arytenoid asymmetry

Este trabalho de doutorado apresenta duas inovações: a Discriminative Paraconsistent Machine (DPM), que consiste em um novo classificador elaborado com base na lógica paraconsistente anotada (LPA) e a aplicação da DPM para a identificação de patologias na laringe, por meio de exames nos sinais de voz de um locutor. Não há relatos na literatura sobre o uso da LPA para construção de um classificador e sobre suas aplicações para a finalidade proposta. Os resultados obtidos são motivadores, indicando um avanço na área. / This PhD thesis presents two novelties: the Discriminative Paraconsistent Machine (DPM), which is a new classifier built on the basis of the annotated paraconsistent logic (APL), and the applications of DPM to identify larynx pathologies, by inspecting a voice signal. There is neither a comment on literature about the use of APL to built a classifier nor about its applications for the proposed application. The results obtained create motivation, showing a clear progress in the field.

Com base em exames como a videolaringoscopia, que é considerado um procedimento médico invasivo e desconfortável, diagnósticos têmsido realizados visando detectar patologias na laringe. Geralmente, esse tipo de exame é realizado somente com solicitação médica e quando alterações na fala já são marcantes, ou há sensação de dor. Nessa fase, muitas vezes a doença está em grau avançado, dificultando o seu tratamento. Com o objetivo de realizar um pré-diagnóstico computacional de tais patologias, este trabalho apresenta uma técnica não invasiva na qual são testados e comparados três classificadores: a Distância Euclidiana, a Rede Neural RBF com o kernel Gaussiano e a Rede Neural RBF com o kernel Gaussiano modificado. Testes realizados com uma base de dados de vozes normais e aquelas afetadas por diversas patologias demonstram a eficácia da técnica proposta, que pode, inclusive, ser implementada em tempo-real. / Based on examinations such as laryngoscopy, which is considered an invasive and uncomfortable procedure, diagnosis have been performed aiming at the detection of larynx pathologies. Usually, this type of test is carried out upon medical request and when the speech changes are notable or are causing pain. At this point, the disease is possibly at an advanced degree, complicating its treatment. In order to perform a computational pre-diagnosis of such conditions, this work proposes a noninvasive technique in which three classifiers are tested and compared: the Euclidean distance, the RBF Neural Network with the Gaussian kernel and RBF Neural Network with a modified Gaussian kernel. Tests carried out with a database of normal voices and those affected by various pathologies demonstrate the effectiveness of the technique that may even be implemented to work in real time.

A detecção de patologias na laringe tem ocorrido basicamente por meio de diagnósticos médicos apoiados em videolaringoscopia, que é considerado um procedimento invasivo e causa certo deconforto ao paciente. Além disso, esse tipo de exame é realizado com solicitação médica e apenas quando as alterações na fala já são marcantes ou estão causando dor. Nesse ponto, muitas vezes a doença já está em grau avançado, dificultando o seu tratamento. Com o objetivo de realizar um pré-diagnóstico de tais patologias, este trabalho propõe uma técnica não invasiva baseada em um novo algoritmo que combina duas Máquinas de Vetores de Suporte, treinadas com o uso de um procedimento de aprendizado semi-supervisionado, alimentadas por um conjunto de parâmetros obtidos com o uso da Transformada Wavelet Discreta do sinal de voz do locutor. Os testes realizados com uma base de dados de vozes normais e afetadas por diversas patologias demonstram a eficácia da técnica proposta que pode, inclusive, ser implementada em tempo-real. / Larynx pathology detection is a process that depends basically on medical diagnosis and is based on videolaringoscopy, which is considered as being an invasive and uncomfortable procedure. Furthermore, this kind of examination depends on a physicists requirement and is carried out only when speech is considerably modified or causing pain. At that level, the problem is in an advanced stage which difficults its treatment. In order to get a pre-diagnosis of such pathologies, this work proposes a non-invasive technique which is based on a new algorithm that combines two support vector machines, trained with a semi-supervised approach, powered by a set of parameters derived from the discrete wavelet transform of the speakers voice signal. Tests carried out with the use of a database of normal and pathological voices show the efficacy of the proposed technique which can also be implemented for use in real-time.

Introdução: A comissura anterior constitui-se em área de infiltração do câncer glótico, mesmo em estádio precoce. Objetivo: Avaliar o acometimento por tumor da cartilagem da comissura anterior em espécimes de laringectomia frontolateral. Métodos: Foram incluídos 48 pacientes submetidos à laringectomia frontolateral por carcinoma espinocelular T1b/T2. Aspectos epidemiológicos, clínicos e análise morfológica histopatológica foram avaliados. Resultados: Quarenta e dois pacientes (87,5%) tinham lesões T1b e seis (12,5%), T2. Trinta e quatro casos (70,8%) apresentaram tecido sadio entre o tumor e a cartilagem tireoidea, 10 casos (20,8%) tinham tumor contíguo à cartilagem e, em quatro casos (8,3%), houve invasão da cartilagem. Não houve maior risco de desfecho adverso nos grupos com infiltração ou tumor adjacente à cartilagem. Grau de diferenciação, índice mitótico, irregularidade nuclear, presença de nucléolo e necrose tumoral não tiveram relação com invasão da cartilagem. Conclusão: A infiltração da cartilagem tireoidea ocorreu em 8,3% dos tumores e não mudou o desfecho em pacientes submetidos à laringectomia fronto-lateral. As características morfológicas não apresentaram significado estatístico / Introduction: The anterior commissure is an area of glottic cancer infiltration, even in early stages. Objective: To evaluate the involvement of cartilage by the tumor of the anterior commissure in surgical specimens of frontolateral laryngectomy. Methods: 48 patients who had undergone frontolateral laryngectomy for T1b/T2 squamous cell carcinoma were included. Epidemiological and clinical aspects as well as morphological histopathological analysis were evaluated. Results: 42 patients (87,5%) had T1b lesions and 6 (12,5%) had T2. Thirty-four cases (70,8%) showed healthy tissue between the tumor and thyroid cartilage, 10 cases (20,8%) had a tumor contiguous with cartilage; and in 4 cases (8,3%) there was cartilage invasion. There was no major risk of adverse closure in the groups with the infiltration or tumor adjacent to cartilage. Grade of cellular differentiation, mitotic index, nuclear irregularity, the presence of nucleolus and tumoral necrosis were not related to cartilage invasion. Conclusion: the infiltration of thyroid cartilage occurred in 8,3% of tumors and did not change the outcome in patients submitted to partial frontolateral laryngectomy. The morphological characteristics did not show any statistical significance

INTRODUÇÃO: A cicatriz em prega vocal que ocorre após injúria constitui causa importante de disfonia. A fonocirurgia ideal é aquela em que a lesão efetivamente removida com o menor dano possível ao tecido adjacente, a fim de reestabelecer a função da prega vocal ao mesmo tempo em que a sua ultraestrutura sua ultraestrutura é preservada. Tanto o bisturi frio quanto lasers em geral são aceitos como instrumentos para fonocirurgia. O laser de diodo tem sido usado no tratamento de doenças laríngeas. Entretanto, não há consenso quanto os parâmetros ideais desse aparelho para tal finalidade. Inexistem trabalhos que mostrem a forma ou a extensão da lesão provocada com laser de diodo em laringe e tampouco as reações histológicas e cicatriciais provocadas por ele. OBJETIVO: O objetivo desta pesquisa é estudar as alterações morfométricas e histopatológicas observadas nas pregas vocais de coelhos, sete dias após a lesão provocada com o laser de diodo, comparando diferentes configurações do dispositivo. MÉTODO: Vinte e um coelhos machos albinos da raça New Zealand foram distribuídos aleatoriamente em três grupos com sete animais por grupo. Foi realizada uma lesão única durante 20 segundos em cada prega vocal com a ponta da fibra em contato superficial com o tecido. Duas frequências de pulso foram comparadas no Grupo I (10Hz versus 1000Hz), diferentes potências no Grupo II (3W versus 5W) e modos de radiação distintos no Grupo III (pulsado versus contínuo). Após sete dias, as laringes foram excisadas e submetidas à coloração com hematoxilina-eosina, além de coloração histoquímica para colágeno e elastina. Foi realizada análise histológica quantitativa e subjetiva. RESULTADOS: o laser de diodo provocou: exocitose de células inflamatórias; edema de mucosa e submucosa; infiltrado celular extenso em torno da úlcera, composto por polimorfonucleares (especialmente eosinófilos), linfócitos e histiócitos; tecido de granulação com a presença de fibroblastos e vasos neoformados e áreas de necrose do tipo coagulativa. A extensão do processo inflamatório e a extensão linear da úlcera apresentaram diferença significativa entre as duas potências, e foi maior com uso do laser ajustado para 5W. A extensão do processo inflamatório, extensão linear da úlcera, profundidade da úlcera e profundidade do processo inflamatório apresentaram diferença significativa entre os dois modos de emissão do laser, isto é, maior no modo contínuo. A densidade das fibras colágenas apresentaram-se elevadas apenas ao uso do laser no modo contínuo, quando comparado ao modo pulsado. Não houve diferença estatística quanto à densidade de fibras elásticas. CONCLUSÃO: O uso do laser de diodo ajustado em potência de 5W ao invés 3W e o uso do modo contínuo ao invés do pulsado são capazes de aumentar significativamente a injúria térmica nas pregas vocais de coelhos / INTRODUCTION. Scarring of the vocal folds is a relevant cause of dysphonia after injury. The ideal phonomicrosurgery would be the one that removes the vocal fold disease in order to restore the biomechanical function, while providing minimal disruption to the surrounding vocal fold layered structure. Steel scalpel and laser systems are widely accepted tools for vocal fold surgical procedures. The diode laser technique has been used in the treatment of laryngeal diseases. However, there is great variability among surgeons with regard to the use of the diode laser for laryngeal surgery and the ideal parameters for this procedure remain unclear. No description of the lesion extent or the vocal fold healing after injury with this device have been reported to date. OBJECTIVE: The aim of this research was to study the morphometric and histopathological changes seen in the vocal fold seven days after injury with the diode laser in a rabbit model, comparing different settings of the device. METHODS: Twenty-one male New Zealand white rabbits were randomized into three groups with seven animals per group. A single spot injury during 20 seconds was performed in each vocal fold with the fiber tip in superficially contact with the tissue. Two pulse frequency were compared in group I (10Hz versus 1000Hz), different powers in group II (3W versus 5W) and distinct wave mode of radiation in group III (pulsed versus continuous). After seven days, the larynges were harvested and subjected to H&E staining, histochemical staining for collagen and elastin, with quantitative and subjective histological analysis. RESULTS: the diode laser provoked exocytosis of inflammatory cells; edema of mucosa and submucosa; extensive cell infiltrate around the ulcer with polymorphonuclear cells (especially eosinophils), lymphocytes and histiocytes; granulation tissue with the presence of fibroblasts and neoformed vessels and areas of coagulative necrosis. The extent of the inflammatory infiltrate and the extent of the ablation crater showed to be greater with the 5W power use. The analyzes of extension of the extent of the inflammatory infiltrate, the extent of the ablation crater, the depth of the ablation crater and depth of the inflammatory process presented greater measurements with the continuous mode. The density of collagen fibers was higher when the laser was used in continuous wave mode. There was no statistically significant difference in elastic fiber density. CONCLUSION: Increasing power from 3W to 5W and using continuous wave rather than pulsed wave mode of the diode laser significantly increased the extent of thermal injury in the rabbit vocal folds

O câncer de laringe pode ser tratado com cirurgias denominadas laringectomias, nas quais toda ou parte da laringe é removida, denominadas a laringectomia total e a parcial respectivamente. Ambos os tipos de cirurgia tem um impacto importante sobre a voz. Os pacientes com problemas de voz freqüentemente referem limitações, frustrações ou até mesmo impedimentos, tanto de natureza física, como psicológica, sociais ou profissionais. Tendo em vista a relação entre a voz e a qualidade de vida (QV), o objetivo deste estudo foi investigar o impacto da disfonia na QV dos pacientes submetidos a laringectomia parcial vertical, uma vez que a principal seqüela dessa cirurgia é a disfonia. Participaram deste estudo 31 pacientes submetidos a laringectomia parcial vertical no departamento de cabeça e pescoço do Hospital Amaral Carvalho entre fevereiro de 1993 e abril de 2005. Todos os pacientes responderam ao protocolo de mensuração de qualidade de vida e voz (QVV), auto-avaliação da voz e tiveram suas vozes avaliadas, quanto ao grau da disfonia, por meio da escala GRBAS. Os resultados obtidos do protocolo QVV foram: escore total \'X BARRA\' = 77,02 \'+ OU -\' 25,10, domínio sócio-emocional \'X BARRA\' = 83,67 \'+ OU -\' 27,51 e domínio do funcionamento físico \'X BARRA\' = 72,58 \'+ OU -\' 24,74. O domínio do funcionamento físico foi que o apresentou escores mais baixos. Quanto à auto-avaliação da voz: a maioria (51,61%) dos pacientes deste estudo classificou suas vozes como boa e observou-se relação positiva entre a auto-avaliação da voz com os valores obtidos em todos os domínios do QVV, uma vez que quanto melhor foi a classificação da voz pelo paciente, maiores foram os escores do QVV indicando melhor QV. Quando correlacionados a média da escala GRBAS com os dados do protocolo QVV, não houve correlação estatisticamente significante. Embora na correlação do G (grau global da disfonia) da GRBAS com o QVV observou-se que, vozes com ) grau discreto de disfonia apresentaram maiores escores do QVV quando comparadas com vozes com graus moderado e severo, refletindo em melhor QV. Concluindo, este estudo demonstrou o impacto negativo da disfonia na QV de pacientes submetidos a laringectomia parcial vertical, uma vez que quanto maior o grau de disfonia, menores os escores do QVV. / The laryngeal cancer can be treated with surgeries denominated laryngectomies, which entire or part of larynx is removed, characterizing total laryngectomy and the partial respectively. Both types of surgery cause a very important impact in the voice. The patients with voice disorder frequently complain about limitations, frustrations or even though disabilities such as physical, psychological, social or professionals. To be considering the relationship between voice and the quality of life, the purpose of this study was research the impact of dysphonia in the quality of life in patients undergone a vertical partial laryngectomy, once the mean sequel of this surgery is the dysphonia. Thirty-one patients undergone a vertical partial laryngectomy in the Departamento de Cabeça e Pescoço do Hospital Amaral Carvalho between February 1993 and April 2005, completed the voice-quality of life QVV (translated and adapted from V-RQOL) questionnaire; self-rating voice and their voices were evaluated, as for the grade of dysphonia through GRBAS. The results obtained from: QVV total \'X BARRA\' = 77,02 e DP = 25,10, social-emotional domain \'X BARRA\' = 83,67 e DP = 27,51 and physical functional domain \'X BARRA\' = 72,58 e DP = 24,74. The physical functional domain showed the lower scores. About the voice self-rating: the majority (51,61%) of patients in this study classified their voices as good showing the positive relationship between self-rating voice with scores of QVV indicating better quality of life. When correlated the mean values of GRBAS with data QVV, statistically significant relationships were not found. In the relationship of G (grade of hoarseness) of GRBAS with the QVV, there was relationship statistically significant relation between voice and quality of life, therefore, voices with discreet grade of dysphonia showed better quality of life when compared with voices moderate and severe grades. In summary, this study demonstrated the negative impact of dysphonia in the quality of life in patients undergone a vertical partial laryngectomy, how at higher the grade of dysphonia, lower is the scores of QVV.

INTRODUÇÃO: A cicatriz em prega vocal que ocorre após injúria constitui causa importante de disfonia. A fonocirurgia ideal é aquela em que a lesão efetivamente removida com o menor dano possível ao tecido adjacente, a fim de reestabelecer a função da prega vocal ao mesmo tempo em que a sua ultraestrutura sua ultraestrutura é preservada. Tanto o bisturi frio quanto lasers em geral são aceitos como instrumentos para fonocirurgia. O laser de diodo tem sido usado no tratamento de doenças laríngeas. Entretanto, não há consenso quanto os parâmetros ideais desse aparelho para tal finalidade. Inexistem trabalhos que mostrem a forma ou a extensão da lesão provocada com laser de diodo em laringe e tampouco as reações histológicas e cicatriciais provocadas por ele. OBJETIVO: O objetivo desta pesquisa é estudar as alterações morfométricas e histopatológicas observadas nas pregas vocais de coelhos, sete dias após a lesão provocada com o laser de diodo, comparando diferentes configurações do dispositivo. MÉTODO: Vinte e um coelhos machos albinos da raça New Zealand foram distribuídos aleatoriamente em três grupos com sete animais por grupo. Foi realizada uma lesão única durante 20 segundos em cada prega vocal com a ponta da fibra em contato superficial com o tecido. Duas frequências de pulso foram comparadas no Grupo I (10Hz versus 1000Hz), diferentes potências no Grupo II (3W versus 5W) e modos de radiação distintos no Grupo III (pulsado versus contínuo). Após sete dias, as laringes foram excisadas e submetidas à coloração com hematoxilina-eosina, além de coloração histoquímica para colágeno e elastina. Foi realizada análise histológica quantitativa e subjetiva. RESULTADOS: o laser de diodo provocou: exocitose de células inflamatórias; edema de mucosa e submucosa; infiltrado celular extenso em torno da úlcera, composto por polimorfonucleares (especialmente eosinófilos), linfócitos e histiócitos; tecido de granulação com a presença de fibroblastos e vasos neoformados e áreas de necrose do tipo coagulativa. A extensão do processo inflamatório e a extensão linear da úlcera apresentaram diferença significativa entre as duas potências, e foi maior com uso do laser ajustado para 5W. A extensão do processo inflamatório, extensão linear da úlcera, profundidade da úlcera e profundidade do processo inflamatório apresentaram diferença significativa entre os dois modos de emissão do laser, isto é, maior no modo contínuo. A densidade das fibras colágenas apresentaram-se elevadas apenas ao uso do laser no modo contínuo, quando comparado ao modo pulsado. Não houve diferença estatística quanto à densidade de fibras elásticas. CONCLUSÃO: O uso do laser de diodo ajustado em potência de 5W ao invés 3W e o uso do modo contínuo ao invés do pulsado são capazes de aumentar significativamente a injúria térmica nas pregas vocais de coelhos / INTRODUCTION. Scarring of the vocal folds is a relevant cause of dysphonia after injury. The ideal phonomicrosurgery would be the one that removes the vocal fold disease in order to restore the biomechanical function, while providing minimal disruption to the surrounding vocal fold layered structure. Steel scalpel and laser systems are widely accepted tools for vocal fold surgical procedures. The diode laser technique has been used in the treatment of laryngeal diseases. However, there is great variability among surgeons with regard to the use of the diode laser for laryngeal surgery and the ideal parameters for this procedure remain unclear. No description of the lesion extent or the vocal fold healing after injury with this device have been reported to date. OBJECTIVE: The aim of this research was to study the morphometric and histopathological changes seen in the vocal fold seven days after injury with the diode laser in a rabbit model, comparing different settings of the device. METHODS: Twenty-one male New Zealand white rabbits were randomized into three groups with seven animals per group. A single spot injury during 20 seconds was performed in each vocal fold with the fiber tip in superficially contact with the tissue. Two pulse frequency were compared in group I (10Hz versus 1000Hz), different powers in group II (3W versus 5W) and distinct wave mode of radiation in group III (pulsed versus continuous). After seven days, the larynges were harvested and subjected to H&E staining, histochemical staining for collagen and elastin, with quantitative and subjective histological analysis. RESULTS: the diode laser provoked exocytosis of inflammatory cells; edema of mucosa and submucosa; extensive cell infiltrate around the ulcer with polymorphonuclear cells (especially eosinophils), lymphocytes and histiocytes; granulation tissue with the presence of fibroblasts and neoformed vessels and areas of coagulative necrosis. The extent of the inflammatory infiltrate and the extent of the ablation crater showed to be greater with the 5W power use. The analyzes of extension of the extent of the inflammatory infiltrate, the extent of the ablation crater, the depth of the ablation crater and depth of the inflammatory process presented greater measurements with the continuous mode. The density of collagen fibers was higher when the laser was used in continuous wave mode. There was no statistically significant difference in elastic fiber density. CONCLUSION: Increasing power from 3W to 5W and using continuous wave rather than pulsed wave mode of the diode laser significantly increased the extent of thermal injury in the rabbit vocal folds