Computational simulation of the adaptive capacity of vein grafts in response to increased pressure.
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.
Abhay B
AB
Ramachandra
Sethuraman
S
Sankaran
Jay D
JD
Humphrey
Alison L
AL
Marsden
D000222:Adaptation, Physiological; D000465:Algorithms; D000818:Animals; D001696:Biomechanical Phenomena; D001794:Blood Pressure; D001807:Blood Vessel Prosthesis; D003198:Computer Simulation; D051379:Mice; D066253:Vascular Remodeling; D014680:Veins / Q000473:pathology / Q000502:physiology*