Computational simulation of the adaptive capacity of vein grafts in response to increased pressure

• Published in: Journal of biomechanical engineering Vol. 137; no. 3
• Main Authors: Ramachandra, Abhay B, Sankaran, Sethuraman, Humphrey, Jay D, Marsden, Alison L
• Format: Journal Article
• Language: English
• Published: United States 01.03.2015
• Subjects: Adaptation, Physiological; Algorithms; Animals; Biomechanical Phenomena; Blood Pressure; Blood Vessel Prosthesis; Computer Simulation; Mice; Vascular Remodeling; Veins - pathology; Veins - physiology
• DOI: 10.1115/1.4029021

Vein maladaptation, leading to poor long-term patency, is a serious clinical problem in patients receiving coronary artery bypass grafts (CABGs) or undergoing related clinical procedures that subject veins to elevated blood flow and pressure. We propose a computational model of venous adaptation to altered pressure based on a constrained mixture theory of growth and remodeling (G&R). We identify constitutive parameters that optimally match biaxial data from a mouse vena cava, then numerically subject the vein to altered pressure conditions and quantify the extent of adaptation for a biologically reasonable set of bounds for G&R parameters. We identify conditions under which a vein graft can adapt optimally and explore physiological constraints that lead to maladaptation. Finally, we test the hypothesis that a gradual, rather than a step, change in pressure will reduce maladaptation. Optimization is used to accelerate parameter identification and numerically evaluate hypotheses of vein remodeling.