Remodelado Histológico en Aneurismas Fusiformes en Ratas Wistar tratadas con Wrapping de Algodón y Politetrafluoroetileno / Histological Remodeling in Fusiform Aneurysms in Wistar Rats Treated with Cotton Wrapping and Polytetrafluoroethylene

Intoducción: El tratamiento microquirúrgico para los aneurismas intracraneales es el clipado, sin embargo, algunos aneurismas deben ser resueltos mediante wrapping. El objetivo del trabajo es analizar los cambios histológicos en aneurismas fusiformes en ratas luego del wrapping con algodón natural y politetrafluoroetileno. Materiales y Método: Se trabajó con 12 Ratas Wistar divididas en 3 grupos. Luego de la anestesia se expusieron ambas arterias carótidas comunes, realizándose un aneurisma fusiforme en cada vaso. Se realizó wrapping a las carótidas derechas, grupo 1 con membrana de politetrafluoroetileno, grupo 2 con algodón natural y grupo 3 empleándo combinación de ambos materiales. Los animales fueron sacrificados a los 45 días postoperatorios, para luego procesar las muestras y análisis histológico vascular. Resultados: En el grupo 1 no se evidenciaron modificaciones estructurales, en el grupo 2 se destacó la presencia de células gigantes multinucleadas, inflamación, con infiltrado linfoplasmocitario. En el grupo 3 fue similar al grupo 2 con el agregado de metaplasia condroide y calcificaciones en capa media. Las arterias carotidas izquierdas (control) no presentaron cambios histológicos y a nivel muscular, aumento del tejido conectivo entre las fibras musculares y fibroblastos en el grupo 2. Discusión: Existen publicaciones sobre la técnica de wrapping con materiales autólogos o heterólogos. Sin embargo, no existen análisis experimentales de los efectos microestructurales producidos en las arterias tras la creación y tratamiento de un aneurisma fusiforme. Conclusiones: La combinación más efectiva para reforzar la pared del aneurisma y evitar la reacción inflamatoria circundante es la utilización de algodón natural y politetrafluoroetileno

Intoduction: The microsurgical treatment for intracranial aneurysms is clipping, however, some aneurysms must be resolved by wrapping. The objective of the work is to analyze the histological changes in fusiforms aneurysms in rats after wrapping with natural cotton and polytetrafluoroethylene. Materials and Method: We worked with 12 Wistar rats divided into 3 groups. After anesthesia, both common carotid arteries were exposed, making a fusiform aneurysm in each vessel. Right carotid wrapping was performed, group 1 with a polytetrafluoroethylene membrane, group 2 with natural cotton, and group 3 using a combination of both materials. The animals were sacrificed 45 days after surgery, to process the specimens and vascular histological analysis. Results: In group 1 there were no structural modifications, in group 2 the presence of multinucleated giant cells, inflammation, with lymphoplasmacytic infiltrate stood out. In group 3 it was similar to group 2 with the addition of chondroid metaplasia and calcifications in the middle layer. The left carotid arteries (control) did not present histological changes and at the muscle level, increased connective tissue between muscle fibers and fibroblasts in group 2. Discussion: There are publications on the wrapping technique with autologous or heterologous materials. However, there are no experimental analyzes of the microstructural effects produced in the arteries after the creation and treatment of a fusiform aneurysm. Conclusions: The most effective combination to reinforce the wall of the aneurysm and avoid the surrounding inflammatory reaction is the use of natural cotton and polytetrafluoroethylene

Short-term outcome of polytetrafluoroethylene membrane valve versus transannular pericardial patch reconstruction of right ventricular outflow tract in tetralogy of fallot: a randomized controlled trial

Abstract Introduction: Reconstruction of right ventricular outflow tract during primary repair of tetralogy of Fallot often requires the placement of a transannular patch which results in pulmonary regurgitation (PR). We compared the short-term outcomes of bicuspid polytetrafluoroethylene membrane valve versus transannular pericardial patch reconstruction of the right ventricular outflow tract. Methods: Thirty consecutive patients undergoing primary repair of tetralogy of Fallot were randomly allocated to two groups - polytetrafluoroethylene valve (PTFEV) group (n=15) and transannular pericardial patch (TAP) group (n=15). The two groups had similar preoperative demographic characteristics. We compared the short-term clinical and echocardiographic outcomes between these groups. The transthoracic echocardiographic follow-up was performed at one week, one month and six months after surgery. Results: The PTFEV group had significantly lower central venous pressure in the immediate postoperative period compared to the TAP group (7.60±2.06 vs. 10.13±1.73, P=0.002). Extubation time was significantly shorter in the PTFEV group compared to the TAP group (12.93±7.55 hrs vs. 22.23±15.11 hrs, P=0.04). PR in the PTFEV group was absent in five patients at 24 hours post-surgery. At the study endpoint, PR was absent in six, trivial in one and mild in eight patients in the PTFEV group compared to TAP group, where all 15 patients had severe PR. Conclusion: The bicuspid polytetrafluoroethylene membrane valves significantly decrease the central venous pressure in the immediate postoperative period, facilitate early extubation and, thus, prevent ventilator-related comorbidities. They achieve a high degree of pulmonary competence and do not increase the right ventricular outflow tract gradient in short-term follow-up.

Infection of expanded polytetrafluoroethylene and Dacron-coated stents with Staphylococcus epidermidis: an experimental study in pigs / Infecção de stents revestidos com politetrafluoretileno expandido e Dacron com Staphylococcus epidermidis: estudo experimental em porcos

Abstract Background Diagnosis of the etiologic agent of endoprosthesis infections is essential to enable treatment, since these infections constitute important complications of endovascular procedures. Sonication of explanted tissue and materials is a technique that can be used to facilitate detection of biofilm-producing bacteria. Objectives To evaluate infection of pigs' aortas after implantation of nitinol stents coated with polytetrafluoroethylene (ePTFE) or Dacron, previously infected with biofilm-producing Staphylococcus epidermidis. Intimal thickening and the inflammatory response in the aortic wall were also evaluated. Methods 11 ePTFE-coated nitinol stents and 10 Dacron stents infected with S. epidermidis strains were implanted in the infrarenal aorta of 21 8-week-old pigs. After 2 weeks, the aorta containing the stents was removed. A vortex mixer and ultrasound were used to homogenize the samples and remove the biofilm. Subsequently, the number of colony-forming units was counted. Results There were no significant differences between the two groups in terms of the number of colony-forming units or of inflammation in the arterial wall. With the exception of one specimen from the Dacron group, all aortic stent cultures were positive for S. epidermidis. Conclusions There were no significant differences in the inflammatory response or infection rate between ePTFE and Dacron-coated stents actively infected with biofilm-producing S. epidermidis. Intimal thickening and the inflammatory response to infection of endoprostheses were similar. These results suggest that the two most widely used stent lining materials have a similar infection rate.

Resumo Contexto O diagnóstico do agente etiológico é essencial para o tratamento das infecções de endoprótese, pois representam uma importante complicação do tratamento endovascular. A sonificação dos tecidos pode ser uma técnica usada para auxiliar na detecção de bactérias produtoras de biofilme. Objetivos Avaliar a infecção da aorta dos porcos após o implante de stents de nitinol revestidos com politetrafluoretileno (ePTFE) ou Dacron, infectados com Staphylococcus epidermidis, produtor de biofilme. O espessamento intimal e a resposta inflamatória na parede aórtica também foram avaliados. Métodos Onze stents de nitinol revestidos com ePTFE e 10 stents de Dacron infectados com cepas de S. epidermidis foram implantados na aorta infrarrenal de 21 porcos com 8 semanas de idade. Após duas semanas, a aorta contendo os stents foi removida. Um misturador de vórtice e ultrassom foram utilizados para homogeneizar as amostras e remover o biofilme. Posteriormente, o número de unidades formadoras de colônias foi contado. Resultados Não houve diferenças significativas no número de unidades formadoras de colônias ou inflamação na parede arterial entre os dois grupos. Todas as culturas de stent aórtico foram positivas para S. epidermidis, exceto uma no grupo Dacron. Conclusões Não houve diferenças significativas na resposta inflamatória ou na taxa de infecção entre os stents revestidos de ePTFE e Dacron, infectados ativamente pelo S. epidermidis produtor de biofilme. O espessamento intimal e a resposta inflamatória à infecção das endopróteses foram semelhantes. Esses resultados sugerem que os dois materiais de revestimento de stent mais amplamente utilizados têm uma taxa de infecção semelhante.

Experimental comparative study of arterial implants made of silicone reinforced with polyester fabric and expanded polytetrafluoroethylene (PTFE) in rabbits aorta / Estudo experimental comparativo de implantes arteriais em silicone com reforço de poliéster e politetrafluoretileno expandido (PTFE) em aorta de coelhos

ABSTRACT Objectives: the aim of this study was to compare the outcomes of a new silicone vascular prostheses with PTFE vascular prostheses, on a rabbit experimental model. Methods: forty rabbits underwent infra-renal aorta replacement with 4 mm diameter prostheses, twenty animals with PDMS and twenty animals with PTFE (control group). Retrograde aortic angiography was performed to assess patency. Histological graft samples were examined by electron microscopy to evaluate prostheses endothelialization. Results: patency rates were 100% for both grafts after 30 days; after 60 days, patency rate for PDMS was 92.3% (±7.4), and 73,8% (±13.1) at 90 days. PTFE grafts had patency rates of 87.5% (±11.7) at 60 and 90 days. No statistically significant difference was found in between groups for patency rates (p=0.62). Postoperative complications (death, paraplegia) rates (p=0.526) and aortic clamping times (p=0.299) were comparable in both groups. No statistically significant difference for stenosis was found on angiographical analysis between groups (p=0.650). Electron microscopy revealed limited anastomotic endothelial ingrowth in both prostheses. Conclusion: in this experimental model, PDMS and PTFE vascular prostheses had comparable outcomes and PDMS prosthesis could be used as a vascular graft.

RESUMO Objetivo: analisar novo tubo de silicone como material para prótese vascular e compará-lo a prótese de PTFE, em modelo experimental com coelhos. Métodos: quarenta coelhos foram submetidos a interposição, na aorta infrarrenal, de próteses de 4mm de diâmetro, sendo 20 animais com PDMS e 20 com PTFE (grupo controle). Foi realizada arteriografia retrógrada da aorta para avaliar a patência das próteses. Para avaliar a endotelização das próteses foi realizada microscopia eletrônica de maneira amostral pareada. Resultados: a patência em 30 dias foi de 100% para as duas próteses. Aos 60 dias, a taxa de patência do PDMS foi de 92,3% (± 7,4), e de 73,8% (±13,1) em 90 dias; as próteses de PTFE tiveram taxas de patência de 87,5% (± 11,7) aos 60 e 90 dias. Não foi observada diferença significativa entre as taxas de patência dos grupos (p=0,62). Não foi observada diferença entre os grupos quanto à evolução com complicações pós-operatórias (p=0,526) e quanto ao tempo de clampeamento da aorta (p=0,299). Não houve diferença significativa entre os grupos quanto ao grau de estenose das próteses (p=0,650) à avaliação angiográfica. A microscopia eletrônica mostrou crescimento endotelial limitado às regiões próximas às anastomoses nos dois tipos de próteses. Conclusões: o PDMS mostrou-se passível de utilização como prótese vascular, com resultados comparáveis aos do PTFE no modelo utilizado.

Comparación de recidiva posterior a hernioplastía diafragmática con cierre directo versus colocación de parche / Comparison of recurrence after diaphragmatic hernioplasties with direct closure versus patch placement

Resumen Objetivo: Investigar con cuál técnica quirúrgica, cierre directo o con parche de Goretex, las hernias diafragmáticas congénitas operadas tienen más recidiva. Metodología: Los datos de los pacientes sometidos a reparación por hernia diafragmática congénita en el Hospital Nacional de Niños, entre enero 2008 y el 31 diciembre de 2017, fueron revisados retrospectivamente. De los 94 pacientes, solo 59 cumplen con los criterios de inclusión. Para la comparación de las variables cuantitativas se empleó pruebas de T de Student e intervalos de confianza al 95 %; las variables cualitativas se analizaron por la prueba de Fisher con un nivel de significancia de 0,05. Resultados: La mayoría de las hernias diafragmáticas operadas fueron izquierdas (78 %) y posterolaterales (91 %). La técnica de reparación más frecuente utilizada fue el cierre directo (68%). Hubo más recidivas posteriores a cierre con parche de Goretex. Se presentaron entre 1 y 12 meses postoperatorio. No hubo diferencia estadísticamente significativa entre recidivas con técnica de cierre directo versus cierre con parche de Goretex. Conclusión: Realizar un cierre directo del diafragma es una buena opción quirúrgica para reparación de hernia diafragmática congénita. No hubo en este estudio diferencias estadísticamente significativas en cuanto a recidiva entre utilizar técnica con cierre directo o con parche.

Abstract Objective: To investigate with which surgical technique, direct closure or use of a Goretex patch, congenital diaphragmatic hernias recurre more. Methodology: The data of the patients who underwent repair of congenital diaphragmatic hernia at the National Children's Hospital from January 2008 to December 31, 2017, were reviewed retrospectively. Of the 94 patients, only 59 met the inclusion criteria. For the comparison of the quantitative variables, Student's t-test and 95% confidence intervals were used, the qualitative variables were analyzed by the Fisher's test with a significance level of 0.05. Results: Most of the operated diaphragmatic hernias were left 78% and posterolateral 91%. The most frequent repair technique used was direct closure, 68%. There were more recurrences after closing when a Goretex patch was used. They occurred between 1 and 12 months post-operatively. There was no statistically significant difference between recurrences with the direct closure technique versus closure with the Goretexpatch. Conclusion: Performing a direct closure of the diaphragm is a good surgical option for surgical repair of congenital diaphragmatic hernias. There were no statistically significant differences in relapse in this study between using the direct closure or patch technique.

Fifteen years of experience with frontalis suspension using polytetrafluoroethylene (Gore-Tex®) suture in blepharoptosis repair / 15 anos de experiência em suspensão frontal com fio de politetrafluoretileno (Gore-Tex®) na correção de ptose palpebral

ABSTRACT Purpose: To review the outcomes of frontalis suspension surgeries with the use of polytetrafluoroethylene in patients with blepharoptosis. Methods: A retrospective observational study analyzed the outcomes of frontalis suspension surgeries performed in a single institution from 2003 to 2018. All procedures were performed with closed incision and single pentagon techniques. Outcomes were classified as satisfactory or unsatisfactory, with satisfactory defined as a margin reflex distance of >3 mm and <1 mm between eyelids and unsatisfactory as hypocorrection, surgical complications, and asymmetry. Results: We included a total of 76 eyelids from 52 patients in our study. Within a mean postoperative follow-up of 16.8 ± 18.5 months (range, 3-95), 59 (77.6%) eyelids had a satisfactory outcome, and 17 (22.4%) were unsatisfactory (8 cases of asymmetry, 3 granulomas, 3 suture extrusions, 2 abscesses, and 1 case of cellulitis). Nine eyelids from the unsatisfactory group required reoperation. Among the patients with a follow-up of ³12 months (38 surgeries), lasting results were observed in most eyelids, except for 2 late-onset suture extrusions. Conclusion: The use of polytetrafluoroethylene in frontalis suspension surgery was shown to be predictable, safe, and lasting. Our findings support previous studies that have shown adequate functional results and low complication rates.

RESUMO Objetivo: Revisar os resultados de cirurgias de sus pensão ao músculo frontal com o uso de fio de politetrafluoretileno em pacientes com blefaroptose. Métodos: Em um estudo observacional retrospectivo, foram analisados os resultados das cirurgias de músculo frontal de uma instituição, realizadas entre 2003 e 2018. Todos os procedimentos foram realizados com incisão fechada e técnica de pentágono. Os desfechos foram classificados como satisfatórios ou insatisfatórios com definição satisfatória definida como distância margem-reflexo >3mm e <1mm entre as pálpebras e insatisfatória como hipocorreção, complicações cirúrgicas e assimetria. Resultados: Incluímos um total de 76 pálpebras de 52 pacientes em nosso estudo. Com um tempo médio de seguimento pós-operatório de 16,8 ± 18,5 meses (intervalo 3-95), 59 (77,6%) pálpebras apresentaram desfecho satisfatório e 17 (22,4%) insatisfatórios (8 casos de assimetria, 3 granulomas, 3 extrusões de sutura, 2 abscessos e 1 caso de celulite). Nove pálpebras do grupo insatisfatório necessitaram de reoperação. Entre os pacientes com seguimento ³12 meses (38 cirurgias), resultados duradouros foram observados na maioria dos casos, exceto por 2 extrusões de sutura de surgimento tardio. Conclusão: O uso de politetrafluoretileno na cirurgia de músculo frontal mostrou ser previsível, seguro e duradouro, Nossos achados corroboram com estudos prévios que mostraram resultados funcionais adequados e baixos índices de complicação.

Comparative study of four different types of intraperitoneal mesh prostheses in rats

Abstract Purpose: To compare four types of mesh regarding visceral adhesions, inflammatory response and incorporation. Methods: Sixty Wistar rats were divided into four groups, with different meshes implanted intraperitoneally: polytetrafluoroethylene (ePTFE group); polypropylene with polydioxanone and oxidized cellulose (PCD); polypropylene (PM) and polypropylene with silicone (PMS). The variables analyzed were: area covered by adhesions, incorporation of the mesh and inflammatory reaction (evaluated histologically and by COX2 immunochemistry). Results: The PMS group had the lowest adhesion area (63.1%) and grade 1 adhesions. The ePTFE and PM groups presented almost the total area of their surface covered by adherences (99.8% and 97.7% respectively) The group ePTFE had the highest percentage of area without incorporation (42%; p <0.001) with no difference between the other meshes. The PMS group had the best incorporation rate. And the histological analysis revealed that the inflammation scores were significantly different. Conclusions: The PM mesh had higher density of adherences, larger area of adherences, adherences to organs and percentage of incorporation. ePTFE had the higher area of adherences and lower incorporation. The PMS mesh performed best in the inflammation score, had a higher incorporation and lower area of adherences, and it was considered the best type of mesh.

Bond strength of resin cements to novel materials to intracanal posts applications / Resistência de união de cimentos resinosos a novos materiais para pinos intrarradiculares

Objective: Evaluate the bond strength of resin cements to new materials for application in intraradicular posts. Material and Methods: Five materials were evaluated: fiberglass, PET, polyethylene, polyacetal and PTFE. Two commercial resin cements (Rely X U200 and Rely X Arc) were applied on the test specimens of the materials (9x3mm) and the bonding was evaluated through the shear bond strength test, where the chisel operated with a load of 1kN and a velocity of 0.5mm/min at the cement/material interface. The data were analyzed by the Shapiro-Wilk test, followed by the two-way analysis of variance, performed with the Bonferroni post-test (α=0.05). Results: The glass fiber was statistically different from all evaluated materials (p0.05). Comparing the two cements, a statistical difference was found between Rely X U200 and Arc only for the glass fiber (p=0). Conclusion: PET, polyethylene, polyacetal and PTFE exhibited reduced bond strength compared to the glass fiber (AU)

Objetivo: Avaliar a resistência de união de cimentos resinosos a novos materiais para aplicação em pinos intrarradiculares. Material e método: Foram avaliados cinco materiais: fibra de vidro, PET, polietileno, poliacetal e PTFE. Dois cimentos resinosos comerciais (Rely X U200 e Rely X Arc) foram aplicados sobre os corpos de prova dos materias (9x3mm) e a resistência de união foi avaliada através do teste de cisalhamento, onde o cinzel atuou com carga de 1kN e velocidade de 0,5mm/min na interface cimento/material. Verificada a normalidade dos dados através do teste Shapiro-Wilk, foi realizada a análise de variância de dois fatores com pós-teste de Bonferroni (α=0,05). Resultados: a fibra de vidro foi diferente estatisticamtente de todos os materiais avaliados (p0,05). Comparando-se os dois cimentos, foi encontrada diferença estatística entre o Rely X U200 e Arc apenas para a fibra de vidro (p=0). Conclusão: PET, polietileno, poliacetal e PTFE apresentaram resistência de união reduzida comparando-se à fibra de vidro. (AU)

Color stability of esthetic coatings applied to nickel-titanium archwires / Estabilidade de cor de revestimentos estéticos aplicados em fios de níquel-titânio

Introduction: Color stability is an important feature to be considered when using esthetic coated archwires. Objective: To evaluate color changes on the surface of esthetic nickel-titanium archwires coated with Teflon (Ortho Organizers, USA) or epoxy resin (Tecnident, Brazil) after immersion in staining solution. Material and method: Twelve 20-mm-long wire segments were used for each type of coating, which were mounted as two test specimens with a width of 7 mm each. The buccal surface of the archwires was evaluated for fluorescence and color measurements both at baseline and after immersion in a staining solution for 21 days using the VITA Easyshade® Compact spectrophotometer (Model DEASYC220). Differences in total color change according to coating type were compared using an independent samples t-test (p<0.05). The surface characteristics of as-received coated archwires were assessed using scanning electron microscopy. Result: Color changes were observed on the esthetic coatings, with a significant difference between the two brands analyzed. Surface analysis revealed flaws such as wear, pitting, elevations, lack of material, granulation, grooves, cracks, and lack of standardization in the coating process in all as-received archwires, but flaws were less evident in epoxy-resin coatings. Conclusion: The two esthetic coatings did not show color stability, but Teflon coatings showed a more intense color change than epoxy-resin coatings.

Introdução: A estabilidade de cor é uma característica importante quando da utilização de fios com revestimentos estéticos. Objetivo: Avaliar, por meio de um estudo in vitro, as alterações de cor na superfície de fios ortodônticos estéticos de níquel-titânio, revestidos por teflon (Ortho Organizers, EUA) ou resina epóxi (Tecnident, Brasil), quando em contato com solução de corante. Material e método: Foram utilizados 12 segmentos de 20 mm de comprimento para cada tipo de revestimento, os quais foram montados em dois corpos de prova com a largura de 7 mm. Os fios foram submetidos à avaliação da superfície vestibular quanto à fluorescência e à leitura colorimétrica inicial e após a imersão em solução de corante por 21 dias, utilizando o espectrofotômetro digital portátil VITA Easyshade® Compact. Alterações na diferença de cor total de acordo com o tipo de revestimento foram verificadas utilizando-se teste o T para amostras independentes (p<0.05). As características da superfície dos revestimentos, nos fios originais, foram avaliadas por meio do microscópio eletrônico de varredura. Resultado: Verificou-se que o revestimento estético sofreu alteração de cor e a diferença foi estatisticamente significante entre os grupos. A análise da superfície demonstrou falhas como: desgaste, depressões, elevações, falta de material, granulações, ranhuras e trincas e falta de padronização na aplicação do revestimento nos fios da mesma marca comercial, sendo essas menos evidentes nos revestimentos de resina epóxi. Conclusão: Os revestimentos estéticos não apresentaram estabilidade de cor e, dentre os tipos, os de teflon evidenciaram alteração mais intensa que os de resina epóxi.

Modified hybrid procedure in hypoplastic left heart syndrome: initial experience of a center in northeastern Brazil

Abstract Introduction: Although it only corresponds to 2.5% of congenital heart defects, hypoplastic left heart syndrome (HLHS) is responsible for more than 25% of cardiac deaths in the first week of life. Palliative surgery performed after the second week of life is considered an important risk factor in the treatment of HLHS. Objective: The aim of this study is to describe the initial experience of a medical center in Northeastern Brazil with a modified off-pump hybrid approach for palliation of HLHS. Methods: From November 2012 through November 2015, the medical records of 8 patients with HLHS undergoing hybrid procedure were retrospectively evaluated in a tertiary private hospital in Northeastern Brazil. The modified off-pump hybrid palliation consisted of stenting of the ductus arteriosus guided by fluoroscopy without contrast and banding of the main pulmonary artery branches. Demographic and clinical variables were recorded for descriptive analysis. Results: Eight patients were included in this study, of whom 37.5% were female. The median age and weight at the time of the procedure was 2 days (p25% and p75% = 2 and 4.5 days, respectively) and 3150 g (p25% and p75% = 3077.5 g and 3400 g, respectively), respectively. The median length in intensive care unit stay was 6 days (p25% and p75% = 3.5% and 8 days, respectively). There were no in-hospital deaths. Four patients have undergone to the second stage of the surgical treatment of HLHS. Conclusion: In this series, the initial experience with the modified off-pump hybrid procedure showed to be safe, allowing a low early mortality rate among children presenting HLHS.

Tiroplastía de medialización con Gore-Tex®: experiencia de 8 años en Hospital Clínico de la Universidad de Chile / Medialization thyroplasty with Gore-Tex®: 8 years experience in Clinical Hospital of the University of Chile

Introducción: La parálisis de cuerda vocal causa disfonía y puede ser complicación posterior a ciertas cirugías. Existen diversos tratamientos, uno de ellos es la tiroplastía de medialización, procedimiento realizado con anestesia local, permitiendo un fino ajuste de la voz. Objetivo: Analizar la experiencia en tiroplastía de medialización con Gore-tex® en el Hospital Clínico de la Universidad de Chile entre los años 2008-2016. Material y método: Estudio descriptivo, retrospectivo, con revisión de fichas clínicas de los pacientes que fueron sometidos a tiroplastía de medialización. Para el análisis de los datos se utilizará la prueba Wilcoxon. Resultados: Se analizaron datos de 21 pacientes, correspondientes a 24 tiroplastías de medialización. La edad promedio fue 54,2 años, 13 parálisis fueron secundarias a cirugía y 8 idiopáticas. En 17 pacientes se obtuvo la encuesta VHI-10 en el pre y posoperatorio, con valores promedio de 33,2y 17,4 (p =0,0003). Cinco pacientes requirieron de algún procedimiento complementario, entre 4 y 22 meses poscirugía: inyección de grasa, de Radiesse y refuerzo con otra prótesis de Gore-teX®. Conclusión: La tiroplastía de medialización es excelente para tratar la parálisis de cuerda vocal unilateral no recuperada en forma espontánea, siendo la encuesta VHI-10 una buena herramienta para evaluar la calidad de la voz.

Introduction: Vocal cord paralysis can cause hoarseness and coud be a complications to following certain surgeries. In its treatment, there are several alternatives, one of them is the medialization thyroplasty. This procedure, is performed under local anesthesia, allowing the fine-tune of the voice. Aim: To analyze the experience in Medialization Thyroplasty with Gore-tex in the Clinical Hospital of the University of Chile between 2008 and 2016. Material and method: Retrospective and descriptive, with the review of patient's clinical records who were treated with medialization thyroplasty. The data analysis is done using Wilcoxon test. Results: Data from 21 patients, corresponding to 24 medialization thyroplasty. The average age was 54.2 years old, 13 paralysis were secondary to surgeries and 8 were Idiopathic. In 17 patients it was posible to get the VHI-10 survey in the pre and postoperative, with an average value of 33.2 and 17.4 (p =0.0003). Five patients required some additional procedure, between 4 and 22 months post surgery: injection of fat, Radiesse and installation of a new Gore-tex prosthesis Conclusions: Medialization thyroplasty is an excellent method to treat paralysis of unilateral vocal cord in cases when is not recovered spontaneously, being the VHI-10 survey a good tool for assessing voice quality.

Preservação do rebordo alveolar com perda óssea vestibular associada a biomaterial e membrana PTFE densa intencionalmente exposta ao meio bucal / Preservation of the alveolar ridge with buccal bone loss associated with biomaterial and d-PTFE membrane intentionally exposed to the buccal environment

O uso de membranas em casos de regeneração óssea guiada tornou-se comum e representa um recurso para ganho de tecido ósseo. As membranas de politetrafluoretileno denso (d-PTFE) são uma opção quando há necessidade de mantê-las expostas ao meio bucal. Neste estudo, relata-se a utilização de uma membrana d-PTFE para regeneração óssea em alvéolo pós-extração em região estética.

The use of membranes in cases of guided bone regeneration has become common and represents a resource for bone tissue gain. Dense polytetrafl uoroethylene (d-PTFE) membranes are an option when there is a need to keep them exposed in the oral cavity. In this study, we report the use of a d-PTFE membrane for bone regeneration in the post-extraction socket in the esthetic zone.

Alternative grafts for brachioaxillary hemodialysis access: 1-year comparative results

BACKGROUND: Many chronic renal patients lack autologous veins in the upper limbs suitable for construction of arteriovenous fistulas for hemodialysis. Alternative fistula options for these patients should be evaluated and compared.OBJECTIVE: To compare different types of grafts used for brachioaxillary access in hemodialysis patients in terms of their patency and complication rates.METHOD: Forty-nine patients free from arterial system abnormalities and with no venous options for creation of arteriovenous fistulae in the arm and/or forearm underwent brachioaxillary bypass with implantation of autologous saphenous vein, polytetrafluoroethylene (PTFE), or PROPATEN(r) grafts. Patients were assessed by Doppler ultrasonography at 3, 6, and 12 months after surgery. RESULTS: The four first saphenous vein grafts had failed by 3 or 6 months after surgery. The autologous saphenous vein group was discontinued at the beginning of the study because of extreme difficulty in achieving puncture and hematoma formation. Failure rates of PTFE and PROPATEN(r) grafts did not differ after 3 (p = 0.559), 6 (p = 0.920), or 12 months (p = 0.514). A log-rank test applied to cumulative survival of grafts at 1 year (0.69 for PTFE, 0.79 for PROPATEN(r)) detected no significant differences (p = 0.938). There were no differences in complications resulting in graft failure between the two types of prosthetic graft.CONCLUSION: Autologous saphenous vein grafts do not appear to be a good option for brachioaxillary hemodialysis access because of difficulties with achieving puncture. Brachioaxillary fistulae constructed using PTFE or PROPATEN(r) grafts exhibited similar patency and complication rates. Further studies with large samples size are warranted to confirm our findings.

CONTEXTO: Há inúmeros pacientes renais crônicos sem veias autólogas nos membros superiores para confecção de fístulas arteriovenosas para realização de hemodiálise. As opções de fístula nestes pacientes devem ser avaliadas e comparadas.OBJETIVO: Comparar diferentes enxertos para acesso braquioaxilar em pacientes hemodialíticos, em relação a permeabilidade e taxas de complicação. MÉTODO: Um grupo de 49 pacientes, sem alterações no sistema arterial e sem opções venosas para criação de fístula arteriovenosa no braço e/ou antebraço, foi submetido a procedimentos cirúrgicos para implante de diferentes enxertos: veia safena autóloga, enxertos de PTFE e PROPATEN(r).RESULTADOS: Os quatro primeiros implantes de veia safena falharam no terceiro e no sexto mês após a cirurgia. Interrompeu-se o uso de veia safena autóloga no início do estudo pela extrema dificuldade de punção e pela formação de hematoma. Não houve diferenças nas taxas de falha dos enxertos de PTFE e PROPATEN(r) após três (p = 0,559), seis (p = 0,920) e 12 meses (p = 0,514) de seguimento. O teste de Logrank aplicado à sobrevida cumulativa dos enxertos por um ano (0,68 para PTFE; 0,79 para PROPATEN(r)) não relevou diferenças (p = 0,938). Não foram encontradas diferenças entre os enxertos prostéticos em relação ao tipo de complicação que determinou as falhas.CONCLUSÃO: O enxerto de veia safena autóloga parece não ser é uma boa opção para acesso braquioaxilar em hemodialíticos, já que implica em dificuldade na punção. Os enxertos de PTFE e PROPATEN(r) em fistula braquioaxilar resultaram em permeabilidade e taxas de complicações similares. Estudos com amostras maiores são necessários para confirmar nossos achados.

Immunolocalization of markers for bone formation during guided bone regeneration in osteopenic rats

Objective The aim of this paper was to evaluate the repair of onlay autogenous bone grafts covered or not covered by an expanded polytetrafluoroethylene (e-PTFE) membrane using immunohistochemistry in rats with induced estrogen deficiency. Material and Methods Eighty female rats were randomly divided into two groups: ovariectomized (OVX) and with a simulation of the surgical procedure (SHAM). Each of these groups was again divided into groups with either placement of an autogenous bone graft alone (BG) or an autogenous bone graft associated with an e-PTFE membrane (BGM). Animals were euthanized on days 0, 7, 21, 45, and 60. The specimens were subjected to immunohistochemistry for bone sialoprotein (BSP), osteonectin (ONC), and osteocalcin (OCC). Results All groups (OVX+BG, OVX+BMG, SHAM+BG, and SHAM+BMG) showed greater bone formation, observed between 7 and 21 days, when BSP and ONC staining were more intense. At the 45-day, the bone graft showed direct bonding to the recipient bed in all specimens. The ONC and OCC showed more expressed in granulation tissue, in the membrane groups, independently of estrogen deficiency. Conclusions The expression of bone forming markers was not negatively influenced by estrogen deficiency. However, the markers could be influenced by the presence of the e-PTFE membrane. .

Early postoperative changes in hematological, erythrocyte aggregation and blood coagulation parameters after unilateral implantation of polytetrafluoroethylene vascular graft in the femoral artery of beagle dogs

PURPOSE: The failure of small-caliber vascular grafts still means a serious problem. Concerning the early postoperative complications we aimed to investigate the hemostaseological and hemorheological aspects of this issue in a canine model. METHODS: In the Control group only anesthesia was induced. In the Grafted group under general anesthesia a 3.5-cm segment was resected unilaterally from the femoral artery and replaced with a PTFE graft (diameter: 3 mm). On the 1st-3rd-5th-7th and 14th postoperative days the skin temperature of both hind limbs was measured, and blood sampling occurred for hematological, hemostaseological and hemorheological tests. RESULTS: The skin temperature of the operated versus intact limbs did not differ. In the Grafted group leukocyte count was elevated by the 1st postoperative day, while platelet count increased over the entire follow-up period. Fibrinogen concentration rose on the 1st-5th days, activated partial thromboplastin time increased on the 3rd-7th days. Erythrocyte aggregation was enhanced significantly on the 1st-5th days. In specimens taken on the 14th day, histologically we found matured thrombus narrowing the graft lumen. CONCLUSIONS: Small-caliber PTFE graft implantation into the femoral artery caused significant changes in several hemostaseological and hemorheological parameters. However, better clarifying the factors leading to early thrombosis of these grafts needs further studies. .

Estudo experimental comparativo de remendos arteriais de polidimetilsiloxano com reforço de tecido de poliéster (PDMSr) versus politetrafluoretileno expandido (PTFEe) em aorta de coelhos / Patch of polydimethylsiloxane reinforced with polyester fabric for aortic angioplasty in rabbits

Introdução: Apesar de bons resultados descritos na literatura, o substituto ideal para a utilização como remendo no fechamento arterial ainda não existe. Por este motivo, ainda há espaço para a busca por remendo que seja biocompatível, e que apresente facilidade de manuseio e resultados satisfatórios. Avaliamos remendos arteriais de silicone (polidimetilsiloxano com reforço em poliéster - PDMSr) em comparação com remendos arteriais de PTFEe. Objetivo: O objetivo deste trabalho é comparar, em modelo experimental, em coelhos, os resultados de remendos arteriais feitos em PDMSr com remendos de PTFEe. Materiais e Método: A amostra foi definida em 10 animais que completassem todas as etapas da pesquisa em cada grupo. Os animais foram submetidos à laparotomia mediana e abertura longitudinal da aorta de aproximadamente 8mm, realizando-se o seu fechamento com remendo do grupo selecionado, seguido do fechamento por planos. Os animais foram mantidos em biotério até o 60º PO, quando, então, realizou-se arteriografia de controle, e análise macro e microscópica de peça. Resultados: Para se atingir a amostra desejada, foram necessários 12 procedimentos no grupo PDMSr e 16 no grupo PTFEe. Ocorreram 2 óbitos no grupo PDMSr e 6 no grupo PTFEe. Apesar do número maior de óbitos no grupo PTFEe não houve diferença estatística na sobrevida entre os grupos. Um animal do grupo PDMSr apresentou monoparesia em pata posterior direita e um animal do grupo PTFEe apresentou hérnia incisional. Não houve diferença estatística nas complicações entre os grupos. O tempo operatório foi estatisticamente maior no grupo PTFEe quando comparamos todos os animais, fato que não se repetiu quando excluímos os animais que faleceram...

Introduction: Although good results are reported for various materials for use as patches for arterial closure, as yet none of these is ideal. Therefore, research is continuing into development of a patch that is biocompatible and provides ease of handling, while having satisfactory outcomes. A new silicone arterial patch (polydimethylsiloxane reinforced with polyester fabric, PDMSr) was compared with patches made of expanded polytetrafluoroethylene (ePTFE). Objective: To compare the outcomes between arterial patches made of PDMSr with those made of ePTFE, in an experimental rabbit model. Materials and Method: Rabbits were placed in two groups, and received either PDMSr or ePTFE arterial patches (PDMSr group and ePTFE group, respectively). The animals underwent laparotomy and longitudinal opening of the aorta, which was then closed with the selected patch, followed by suture of all layers. The animals were kept in their cages until the 60th postoperative day, when arteriography, removal of the aorta, and macroscopic and optic and scanning electron microscopic analyzes of the aorta were performed. Ten rabbits from each group that had completed all stages of the research were included in analyses. Results: Twelve procedures were performed in the PDMSr group and 16 in the ePTFE group. There were 2 deaths in the PDMSr group and 6 in the ePTFE group. Despite the higher number of deaths in the ePTFE group, there was no statistical difference in survival rate between the groups. One animal in the PDMSr group developed monoparesis in its right hind paw and 1 animal in the ePTFE group had an incisional hernia. There was no statistical difference in complications between the groups. The operative time was significantly longer in the ePTFE group when all animals were included in analysis, but not when animals that died were excluded...

Histomorphometric, radiographic and biomechanical analyses of platelet rich plasma associated with autogenous bone graft / Efeito do plasma rico em plaquetas associado ao enxerto autógeno na tíbia de coelhos: estudo histomorfométrico,radiográfico e biomecânico

Objective: The aim of this study was to evaluate the effectiveness of platelet rich plasma with and without autogenous bone graft in the bone repair of surgical defects in rabbit tibias. Material and Methods: In this research, 25 adult male rabbits were used. Two defects have been performed in each tibia, divided into four groups: control (C = defect naturally left to heal by clot formation), autogenous (A = bone defect + autogenous graft), PRP (PRP = bone defect + PRP) and autogenous + PRP (PRPA = bone defect + autogenous graft + PRP). All the defects were covered with a dPTFE membrane. Five other animals were sacrificed at 15, 30, and 60-day postoperatively. The pieces containing the defects were processed for histological and histomorphometric analysis. Other five animals were sacrificed after 30 and 60 days and submitted to biomechanical analysis, and all the specimens were sent to the radiographic evaluation of optical density. Results: The biomechanical, radiographic, and histomorphometric results showed larger resistance, optical density, and improving bone formation in the groups A and PRPA when compared with the groups C and PRP. Conclusion: This study showed there was not an improvement in the radiographic, mechanical, and bone formation parameters when PRP was used individually or associated to the autogenous bone graft...

Objetivo: O propósito deste trabalho foi avaliar o efeito do plasma rico em plaquetas associados ou não ao enxerto ósseo autógeno no processo de reparação óssea em defeitos cirúrgicos confeccionados na tíbia de coelhos. Material e Métodos: Nesta pesquisa foram utilizados 25 coelhos adultos, nos quais foram realizados 2 defeitos em cada tíbia, divididos nos seguintes grupos de acordo com o tratamento: controle (C - defeito preenchido somente por coágulo sangüíneo), autógeno (A - defeito + enxerto), PRP (PRP = defeito + PRP) e autógeno + PRP (PRPA - defeito + enxerto + PRP). Todos os defeitos foram recobertos com uma barreira de PTFE e decorridos 15, 30 e 60 dias, 5 animais foram sacrificados por período, sendo as peças contendo os defeitos processadas para análises histológica e histomorfométrica. Outros 5 animais foram sacrificados aos 30 e 60 dias e submetidos à análise das propriedades biomecânicas e todos os espécimes foram submetidos ao exame radiográfico para análise da densidade óptica. Resutados: Os resultados biomecânicos, radiográficos e histomorfométricos mostraram maior resistência, densidade óptica e maior formação óssea nos grupos A e PRPA quando comparados com os grupos C e PRP. Conclusão: Os resultados obtidos possibilitaram concluir que não houve uma melhora nos parâmetros radiográficos, mecânicos e na neoformação óssea quando o PRP foi usado isoladamente ou associado ao enxerto ósseo autógeno...

Estudo experimental comparativo de implantes arteriais: politetrafluoretileno expandido (PTFE) versus polidimetilsiloxano com reforço de tecido de poliéster / Experimental comparative study of arterial implants - expanded polytetrafluoroethylene (PTFE) versus dimethylpolysiloxane reinforced with polyester fabric

INTRODUÇÃO: Os enxertos vasculares sintéticos disponíveis atualmente apresentam baixos índices de patência, quando utilizados na revascularização de vasos de pequeno calibre, e possuem resultados inferiores quando comparados ao uso de veias autólogas em derivações infrageniculares. Nova prótese de pequeno calibre confeccionada em silicone (polidimetilsiloxano, PDMS) com reforço de tecido de poliéster foi desenvolvida e comparada à prótese de PTFE. OBJETIVOS: Analisar, em modelo experimental em coelhos, o tubo de PDMS como material para prótese vascular e compará-lo a prótese de PTFE. MÉTODOS: Quarenta coelhos foram submetidos a interposição na aorta infrarrenal de próteses de 4mm de diâmetro, sendo 20 animais com PDMS e 20 com PTFE (grupo controle). Foi medido o tempo de clampeamento e realizada arteriografia retrógrada da aorta para avaliar a patência das próteses. Para avaliar a endotelização das próteses foi realizada microscopia eletrônica de maneira amostral pareada. RESULTADOS: Vinte e cinco animais (62,5%) não apresentaram intercorrências pós-operatórias; oito (20%) morreram precocemente e sete (17,5%) ficaram paraplégicos no pós-operatório imediato (e foram sacrificados), sendo que esses animais não foram incluídos nas análises de patência. Não foi observada diferença entre os grupos quanto à evolução com complicações pós-operatórias (p=0,526) e quanto ao tempo de clampeamento da aorta (p=0,299). A patência em 30 dias foi de 100% para as duas próteses. Aos 60 dias, a taxa de patência do PDMS foi de 92,3% (± 7,4), e de 73,8% (±13,1) em 90 dias; as próteses de PTFE tiveram taxas de patência de 87,5% (± 11,7) aos 60 e 90 dias. Não foi observada diferença significativa entre as taxas de patência dos grupos (p=0,62). Não houve diferença siginificativa entre os grupos quanto ao grau de estenose das próteses patentes (p=0,650) à avaliação angiográfica. A microscopia eletrônica mostrou crescimento endotelial limitado às regiões próximas...

INTRODUCTION: Synthetic vascular grafts currently available have suboptimal patency rates in small-diameter vessels and inferior outcomes in below-the-knee arterial bypass procedures when compared to the use of autologous vein. A new small vessel prosthesis made of silicone (polydimethylsiloxane, PDMS) and reinforced with polyester fabric was developed and compared to the standard PTFE prosthesis. OBJECTIVES: On a rabbit experimental model, we compared the outcomes of new PDMS vascular prostheses with PTFE vascular prostheses. METHODS: Forty rabbits underwent infra-renal aorta replacement with 4 mm diameter prostheses, twenty animals with PDMS and twenty animals with PTFE (control group). Aortic clamping time was measured and retrograde aortic angiography was performed to assess patency. Histological graft samples were examined by electron microscopy to evaluate prostheses endothelialization. RESULTS: Twenty-five (62,5%) animals had good surgical outcome; eight animals (20%) expired and seven animals (17.5%) became paraplegic (and subsequently sacrificed) during early follow up and were not included in anastomosis patency analysis. Postoperative complications (death, paraplegia) rates (p=0,526) and aortic clamping times (p=0,299) were comparable in both groups. Patency rates in 30 days were 100% for both grafts. At 60 days, patency rate for PDMS was 92,3% (±7,4), and 73,8% (±13,1) at 90 days. PTFE grafts had patency rates of 87,5% (±11,7) at 60 and 90 days. No statistically significant difference was found in between groups for patency rates (p=0,62). No statistically significant difference for stenosis was found on angiographical analysis in between groups (p=0,650). Electron microscopy revealed limited anastomotic endothelial ingrowth in both prostheses used. CONCLUSION: In this experimental model, PDMS and PTFE vascular prostheses had comparable outcomes and PDMS prosthesis could be used as a vacular graft