A device for the application of cyclic twist and extension on perfused vascular segments

Cyclic strain is known to influence many aspects of vascular cell biology, including macromolecular biosynthesis, cell proliferation, and cell morphology. The simulation of the cyclic strain associated with the vasculature in situ has been carried out mostly using devices that manipulated flat membranes on which the cells of choice are cultured. The purpose of this work was to create an apparatus wherein cyclic strains consistent with those found in native blood vessels could be applied to intact three-dimensional (tubular) specimens perfused ex vivo. The cyclic strain protocols using our apparatus may be any combination of axial stretch and twist. Concurrently, the perfusion flow and shear stress are controlled as desired. Vessel diameter, intraluminal pressure, volume flow, and regional strain are measured and stored on line. To illustrate the application of the device, we present hemodynamic and kinematic data collected from a human saphenous vein segment perfused under steady-flow conditions while subjected to cyclic stretch and twist.