Noninvasive determination of perfused artery dimensions ex vivo using a pressure-diameter relationship

Based on the decisive effects of the hemodynamic and mechanical environments on the development and remodeling of arteries in vivo, several groups have cultured tissue-engineered vessels and excised vessels in various mechanically active perfusion systems. To facilitate the interpretation and design of such studies, accurate estimates of the applied forces and resulting stresses are required, which in turn require an accurate estimate of vessel dimensions. The measured pressure drop along the length of the vessel could be used to calculate the average inner diameter, but practical considerations, including the modest accuracy of many pressure transducers, limit this approach. Using nine porcine arteries harvested from pigs weighing between 25 and 100 kg, we show that when real-time measurements of the pressure drop and the outer diameter during a vasoactive event are fit to a theoretical model, offset errors in the pressure measurement can be compensated for and estimates of vessel wall transverse area with an average error of 4.1% (not exceeding 8.3%) are achieved.