Design and validation of a system to simulate coronary flexure dynamics on arterial segments perfused ex vivo

Abstract

Cyclic flexure of the coronary arteries can lead to spatially varying fluid and solid stress patterns. These patterns may explain the heterogenous distribution of atherosclerotic lesions. Here we describe the design and validation of an experimental system to simulate coronary-like flexure dynamics on intact arterial segments ex vivo. Our previously described ex vivo perfusion system was modified with a polymer flexure membrane controlled by a custom data acquisition/motion control system. The system was validated by perfusing arterial segments with pulsatile hemodynamics with or without cyclic flexure. Digital images were obtained to quantify dynamic vessel curvature and arc length. Tissue integrity was assessed by histology. The device generated physiologic curvatures (0-1.8 cm(-1)) at 1 Hz with a physiologic phase relationship with the pressure waveform. Additionally, the in vivo longitudinal extension ratio (40%) was maintained within 2.3% during the flexure cycle. Twelve hours of cyclic contact with the membrane did not compromise arterial segment integrity. This device provides a novel method to examine how the local biomechanical milieu could impact atherosclerotic lesion localization.