Changes in vein dynamics ranging from low to high pressure levels as a determinant of the differences in vein adaptation to arterial hemodynamic conditions.
The causes of the regional differences in venous grafts patency rates are partially understood. Differences in vein dynamics during physiological situations could determine differences in veins' capability to face arterial conditions and could contribute to the dissimilar performance of veins as arterial grafts. In vitro pressure and diameter were measured in four different veins during physiological and arterial (graft) pressure conditions. A diameter-pressure transfer function was designed. Compliance, viscous and inertial properties; circumferential stresses and deformation; and buffering function were calculated. Regional differences in veins' dynamics, but not in buffering function were found during physiological and arterial conditions. The back vein (femoral) showed the least changes when submitted to arterial conditions. Arterial conditions represent different changes in vein dynamics depending on the segment considered. The regional differences in vein dynamics, both at physiological and graft conditions, could contribute to explain the dissimilar results of venous grafts.
Zócalo
Yanina
Y
Physiology Department, School of Medicine, Republic University, Montevideo, Uruguay.
Bia
Daniel
D
Pessana
Franco M
FM
Armentano
Ricardo L
RL
D000222:Adaptation, Physiological; D000818:Animals; D001158:Arteries / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology*; D018056:Hemorheology; D011673:Pulsatile Flow; D012039:Regional Blood Flow / Q000502:physiology; D012756:Sheep; D014680:Veins / Q000502:physiology / Q000637:transplantation*