Acute and chronic changes in porcine rete mirabile after embolization with the Menox system: angiographic and histopathological analyses / Alterações angiográficas e histopatológicas agudas e crônicas da rete mirabile no modelo suíno com sistema embólico líquido Menox

Abstract Objective: To evaluate acute and chronic changes seen on angiographic and histopathological studies of porcine rete mirabile, comparing those treated with the Menox liquid embolic system (LES) and those treated with the Onyx LES. Materials and Methods: Five pigs, each weighing approximately 35 kg, were submitted to rete mirabile embolization under general anesthesia and fluoroscopic guidance, with the Menox LES or Onyx LES. Four animals were treated with the Menox LES and underwent cerebral angiography, followed by euthanasia, at 1, 30, 60, and 90 days after embolization. One animal was treated with the Onyx LES underwent the same procedures at 30 days after embolization. In a subsequent histopathological analysis, we compared the Menox LES and Onyx LES in terms of the acute and chronic changes observed. Results: We observed no significant changes in blood pressure, heart rate, or electrocardiographic parameters that could be attributed to the super-selective infusion of dimethyl sulfoxide or the Menox embolic agent. Fluoroscopy showed adequate material opacity, appropriate progression to the center of the rete mirabile and complete unilateral embolization. Microcatheters were uneventfully detached from the embolized nidus. We observed mild to moderate intravascular and extravascular inflammatory responses, without histological evidence of necrotizing arteritis. There were no adverse neurovascular events. Conclusion: The Menox LES appears to be safe and effective, as well as being apparently equivalent to the Onyx LES in terms of the postprocedure angiographic and histopathological findings.

Resumo Objetivo: Avaliar as alterações angiográficas e histopatológicas agudas e crônicas em rete mirabile suína tratadas com o Menox liquid embolic system (LES) e comparar essas alterações com a embolização com Onyx LES. Materiais e Métodos: A embolização da rete mirabile com Menox LES e Onyx LES foi realizada em cinco suínos pesando cerca de 35 kg sob anestesia geral e orientação fluoroscópica. Quatro animais tratados com Menox LES foram submetidos a angiografia cerebral seguida de eutanásia após 1, 30, 60 e 90 dias e um animal tratado com Onix LES foi submetido ao mesmo procedimento após 30 dias. A análise histopatológica subsequente para alterações agudas e crônicas avaliou o desempenho do Menox LES comparado ao Onyx LES. Resultados: Não foram observadas alterações significativas atribuíveis à infusão superseletiva de dimetilsulfóxido ou Menox nos parâmetros de pressão arterial, frequência cardíaca ou eletrocardiograma. A fluoroscopia mostrou opacidade adequada do material, progressão adequada para o centro da rete mirabile e embolização unilateral completa. Os microcateteres foram retirados do nidus embolizado sem complicações. Observou-se resposta inflamatória intravascular e extravascular leve a moderada, sem indício histológico de arterite necrosante. Nenhum dos casos apresentou eventos neurovasculares adversos. Conclusão: A injeção de Menox LES mostrou-se segura e eficaz, além de ser equivalente ao Onyx LES em relação aos achados angiográficos e histopatológicos pós-procedimento.

Complete depigmentation of a small aperture corneal inlay implanted for compensation of presbyopia / Despigmentação completa de um implante corneano de pequena abertura para correção da presbiopia

ABSTRACT We describe a case of late-onset remarkable depigmentation of a small aperture corneal inlay implanted for presbyopia compensation. The patient was a participant in a clinical trial designed to evaluate the safety and efficacy of the AcuFocusTM ACU-10R160, which is a 10 µm-thick polyimide film tinted with an organic dye. Inlay implantation occurred under mechanical microkeratome Lasik flaps set for a depth of 120 µm. The patient returned to the clinic 11 years after surgery and reported loss of near-vision acuity. Clinical examination showed the complete absence of pigments in the device and the total loss of the initial effect on near vision, despite normal distance vision. Manifest refraction remained stable during the follow-up period. Scheimpflug images characterized the loss of the small aperture effect on incoming light. Confocal analysis revealed small hyper-reflective round images on the endothelium and no signs of inflammation.

RESUMO Descrevemos um caso de importante despigmentação de início tardio de implante corneano de pequena abertura implantada para compensação de presbiopia. O paciente foi um dos participantes de ensaio clínico destinado a avaliar a segurança e eficácia do AcuFocusTM ACU-10R160, uma película de poliimida de 10 microns de espessura, tingida com um corante orgânico. A implantação ocorreu sob um flap de Lasik criado por microcerátomo mecânico ajustado para profundidade de 120 µm. O caso aqui descrito foi avaliado 11 anos após a cirurgia, relatando diminuição de acuidade de visão para perto. O exame clínico mostrou ausência total de pigmentos no dispositivo e perda total do efeito inicial na visão de perto, apesar da visão normal para distância. A refração manifesta permaneceu estável durante o período de seguimento. As imagens de Scheimpflug caracterizaram a perda do efeito da abertura pequena na luz entrante. A análise de microscopia confocal revelou pequenas imagens hiper-reflexivas redondas sobre o endotélio, sem sinais de inflamação.

Comparison of Onxy and N-butyl-2-cyanoacrylate for the embolization of cerebral arteriovenous malformations / 国际脑血管病杂志

Objective To compare the effectiveness and safety of Onyx and n-butyl-2-cyanoacryhte (NBCA) for the embolization of cerebral arteriovenous malformations (AVMs).Methods The clinical data of 53 patients with cerebral AVMs (31 in the NBCA group and 22 in the Onyx group) were analyzed retrospectively.The safety and effectiveness of the 1-year follow-up were compared.The size of AVMs (diameters ＜3 cm,3-6 cm,and ＞6 cm) and the Spetzler-Martin grade were used to conduct subgroup analysis.Results There were no significant differences in the baseline data and AVM morphologies.The embolization rate in the Onyx group was significantly higher than that in the NBCA group (P ＜ 0.05),but there were no significant differences in the incidences of postoperative hemorrhage (1/22 vs.1/31;P=1.000)and neurological deficit (1/22 vs.3/31;P=0.633) in the 1-year follow-up after procedure.The subgroup analysis showed that the embolization rates of the small and medium-sized cerebral AVMs in the Onyx group were significantly higher than those in the NBCA group (all P ＜ 0.05),and the embolization rates of cerebral AVMs with different Spetzler-Martin grades in were significantly higher than those in the NBCA group (all P ＜0.05).Conclusion Onyx is equivalent to NBCA in safety but better in efficacy.

Estudo da ação da saliva nas propriedades mecânicas de protetores bucais para esporte / Study on the effect of saliva on the mechanical properties of mouth protectors for sports

Introdução - A eficiência e a durabilidade de protetores bucais para esporte dependem diretamente da forma com que são usados, pois sempre se apresentam em condições básicas de presença ou ausência de saliva. Para observar se essa condição de uso interfere em suas propriedades mecânicas este trabalho observa através de modelo experimental de arcos dentais obtidos em epóxi, acoplados a uma máquina universal de ensaios Kratos programada para movimento de compressão, o comportamento mecânico de protetores bucais para esporte, confeccionados -m copolímero de etileno e acetato de vinila ? EVA, posicionados no arco superior. Material e Métodos - Foram formados dois grupos de estudo: protetores bucais secos e protetores bucais saturados em saliva artificial, sendo estes últimos obtidos através de análise de saturação com o auxilio de balança analítica para observação de ganho de massa. As propriedades mecânicas observadasforam força máxima e energia absorvida. Resultados - Os resultados foram submetidos a analise estatística t-student (p < 0,05). Observou-se que no grupo dos protetores bucais saturados com saliva houve redução da força máxima (p = 0,00) devido a plastificação do material, responsável pela redução das forças intermoleculares ocasionando maior deformabilidade do protetor atestado pelo aumento da energia absorvida (p = 0,05) quando comparado ao grupo dos protetores secos. Conclusão - Conclui-se que a presença da saliva altera o comportamento mecânico do protetor bucal confeccionado em EVA tornando-o mais dúctil, portanto diminuindo a probabilidadede fraturas dentais e/ou lesões em tecidos circunvizinhos.

Introduction - The efficiency and durability of mouth protectors for sports depend directly on the way they are used, mainly because of their frequent exposure to saliva. To analise if this condition of use affects their mechanical properties, this paper observes, through the use of an experimental model made of epoxy, connected to an universal testing machine Kratos programmed to compress, the mechanical behaviour of mouth protectors for sports, made of ethylene and vinyl acetate copolymer - EVA, positioned on the superior arch. Two groups of study were created: dry mouth protectors and artificial saliva saturated mouth protectors, the second of which was analised with the use of an analitical balance to measure the level of saturation through the gain of mass.The mechanical properties observed were maximal strength and absorbed energy. The results were submitted to t-student statistical analisis method (p < 0,05). It was observed that, in the saturated mouth protectors group, the maximal strength diminished (p = 0,00) due to the material plastification, that caused a reduction in the intermolecular force and consequently a bigger deformation of the protector, confirmed by the increase in the absorbed energy (p = 0,05) when compared to the dry protectors group. It was concluded that the presence of saliva changes the mechanical behaviour of the mouth protector made of EVA, making it more flexible and reducing the probability of dental fractures and/or injuries on adjacent tissues.

Bioavailability of EVA-Coated Metallic Stents Implanted in the Rabbit Iliac Artery

BACKGROUND AND OBJECTIVES: Coronary artery stenting actually shows a high efficacy in the treatment of coronary heart disease, but has the major limitation of restenosis. The ethylene-vinyl acetate copolymer (EVA), a biocompatible nondegradable copolymer, has been employed as a rate-controlling membrane in several drug delivery systems. Herein, the feasibility of an EVA-coated coronary stent was evaluated as a possible route for localized drug delivery. MATERIALS AND METHODS: A total of 15 rabbits were employed in this study. An uncoated stent was implanted into the non-diseased iliac artery in six rabbits, and an EVA-coated stent into a further nine. On the 30th day following the stent implantations, stented segments of the iliac arteries were removed for histological processing and morphometric analysis. RESULTS: The mean neointimal area of the uncoated and coated groups were 1.009 and 1.011 mm2 (p=0.56), respectively. No inflammatory cells were found in coated group. There were no apparent differences between the two groups. CONCLUSION: The results from this study have demonstrated that an EVA-coated coronary stent might be an appropriate method for the controlled-release of a drug.