PURPOSE: To study possible differences in mechanical properties between central (abdominal aorta) and more peripheral (common carotid and common femoral) arteries validating an earlier non-invasive study in children showing that central arteries are more distensible than peripheral ones. As invasive blood pressure was needed, but ethically impossible to obtain in children in an experimental setting, an animal model was chosen. DESIGN: Open experimental study. SETTING: Animal laboratory at university hospital. MATERIAL AND METHODS: The pulsatile vessel wall movements of the abdominal aorta (AA), common femoral (CFA) and common carotid (CCA) artery of nine sheep were examined using an ultrasound phase-locked echo-tracking technique. Intra-arterial blood pressure was measured and pressure-diameter relations, pressure strain elastic modulus (Ep) and stiffness (beta) calculated. Distensibility was defined as the inverse of Ep and stiffness. RESULTS: The AA showed lower values for Ep and stiffness (beta) than the CFA (p = 0.002) and CCA (p = 0.006), i.e. the latter two vessels were stiffer. The pressure-diameter relations confirmed these differences and showed a non-linearity for all three vessels with increased stiffness above 70-90 mm Hg. CONCLUSION: This study on young animals supports earlier findings of differences in mechanical properties between central and more peripheral arteries seen in healthy children. As pathologies between these vessels differ, with dilatation of the abdominal aorta and occlusive disease in the more peripheral vessels, part of the explanation might be found in the mechanical properties of the healthy vessels, characterised here with the echo-tracking technique.
PURPOSE: To study possible differences in mechanical properties between central (abdominal aorta) and more peripheral (common carotid and common femoral) arteries validating an earlier non-invasive study in children showing that central arteries are more distensible than peripheral ones. As invasive blood pressure was needed, but ethically impossible to obtain in children in an experimental setting, an animal model was chosen. DESIGN: Open experimental study. SETTING: Animal laboratory at university hospital. MATERIAL AND METHODS: The pulsatile vessel wall movements of the abdominal aorta (AA), common femoral (CFA) and common carotid (CCA) artery of nine sheep were examined using an ultrasound phase-locked echo-tracking technique. Intra-arterial blood pressure was measured and pressure-diameter relations, pressure strain elastic modulus (Ep) and stiffness (beta) calculated. Distensibility was defined as the inverse of Ep and stiffness. RESULTS: The AA showed lower values for Ep and stiffness (beta) than the CFA (p = 0.002) and CCA (p = 0.006), i.e. the latter two vessels were stiffer. The pressure-diameter relations confirmed these differences and showed a non-linearity for all three vessels with increased stiffness above 70-90 mm Hg. CONCLUSION: This study on young animals supports earlier findings of differences in mechanical properties between central and more peripheral arteries seen in healthy children. As pathologies between these vessels differ, with dilatation of the abdominal aorta and occlusive disease in the more peripheral vessels, part of the explanation might be found in the mechanical properties of the healthy vessels, characterised here with the echo-tracking technique.
Authors: Andreas J Schriefl; Georg Zeindlinger; David M Pierce; Peter Regitnig; Gerhard A Holzapfel Journal: J R Soc Interface Date: 2011-12-14 Impact factor: 4.118
Authors: Nan Qi; Hao Gao; Raymond W Ogden; Nicholas A Hill; Gerhard A Holzapfel; Hai-Chao Han; Xiaoyu Luo Journal: J Mech Behav Biomed Mater Date: 2015-06-20