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.

Upper limb revascularization with reversed vein graft and microvascular anastomoses after brachial artery aneurysm resection in a child with tuberous sclerosis

The authors present an unusual case of a 3-year-old girl who was diagnosed with a fast-growing brachial aneurysm due to tuberous sclerosis. The patient underwent aneurysm resection and microsurgical reconstruction with reversed greater saphenous vein graft at the same time. She had a favorable outcome, without neuromuscular deficits. Doppler ultrasonography was performed for diagnosis, vein graft selection, and postoperative follow-up. The authors believe that such combined approach may be the routine for pediatric vascular reconstructions. Finally, this reconstruction has been rarely reported in tuberous sclerosis patients...