Resumo

BIA, D. et al. In vitro model to study arterial wall dynamics through pressure-diameter relationship analysis. Lat. Am. appl. res. [online]. 2005, vol.35, n.3, pp.217-224. ISSN 0327-0793.

This work describes the biophysical basis of blood vessels' wall dynamics and reports a methodology developed in our laboratory to characterize mechanical vessels' wall properties and those of vascular prostheses. Our study includes in vitro measurements of arteries, veins and ePTFE conduits placed in a circulating loop. Segments are allowed to equilibrate for a period of 15 minutes under a steady state of flow (150 ml/min) and a mean pressure of 93 mmHg, at a stretching rate of 110 beats/min. Data analysis consisted in obtaining pressure-diameter loop in order to calculate: Incremental elastic modulus, wall viscosity, Peterson modulus, pulse wave velocity, characteristic impedance, stiffness index, cross sectional compliance and distensibility. Incremental elastic modulus of ePTFE (48.56±0.82 10⁷dyn/cm²) was significantly higher than that of the veins (26.19±19.90 10⁷dyn/cm²) and that of the arteries (4.06±2.55 10⁷dyn/cm²). This is an important approach, since mechanical wall dynamics plays a major role in vascular disease.

Palavras-chave : Arterial Wall; Circulating Loop; Viscosity; Elasticity.

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