Twist buckling of veins under torsional loading

Abstract

Veins are often subjected to torsion and twisted veins can hinder and disrupt normal blood flow but their mechanical behavior under torsion is poorly understood. The objective of this study was to investigate the twist deformation and buckling behavior of veins under torsion. Twist buckling tests was performed on porcine internal jugular veins (IJVs) and human great saphenous veins (GSVs) at various axial stretch ratio and lumen pressure conditions to determine their critical buckling torques and critical buckling twist angles. The mechanical behavior under torsion was characterized using a two-fiber strain energy density function and the buckling behavior was then simulated using finite element analysis. Our results demonstrated that twist buckling occurred in all veins under excessive torque characterized by a sudden kink formation. The critical buckling torque increased significantly with increasing lumen pressure for both porcine IJV and human GSV. But lumen pressure and axial stretch had little effect on the critical twist angle. The human GSVs are stiffer than the porcine IJVs. Finite element simulations captured the buckling behavior for individual veins under simultaneous extension, inflation, and torsion with strong correlation between predicted critical buckling torques and experimental data (R2=0.96). We conclude that veins can buckle under torsion loading and the lumen pressure significantly affects the critical buckling torque. These results improve our understanding of vein twist behavior and help identify key factors associated in the formation of twisted veins.

Mechanical analysis of a novel biodegradable zinc alloy stent based on a degradation model

“…One limitation is that the vessel wall as an isotropic hyperelastic material whose constitutive relationship is present as a six-parameter Odgen hyperelastic constitutive equation, although the constitutive equation of the vessel varies according to the vessel type [27, 28]. Fetamifar et al [27] developed the lumen buckling equation for nonlinear anisotropic thick-walled arteries to determine the effect of axial tension based on exponential Fung strain function.…”

“…Fetamifar et al [27] developed the lumen buckling equation for nonlinear anisotropic thick-walled arteries to determine the effect of axial tension based on exponential Fung strain function. Garcia et al [28] used a two-fiber strain energy density function to characterize the mechanical behavior of veins under torsion. In future research, scaffold effects of the patented stent when it is deployed into stenotic vessels with different types and materials will be investigated.…”

Arterial wall remodeling under sustained axial twisting in rats

“…The shear strain and principal strain direction were determined using the methods as previously described (Wang et al 2015; Garcia et al 2017). Briefly, arteries were modeled as circular cylinders under an axial force (N), lumen pressure (P i ), and torque (T).…”

“…Severe twisting of arteries and veins can affect their patency, impair endothelium function and delay wound healing in the anastomosis area, and lead to distal ischemia (Barton and Margolis 1975; Endean et al 1989; Izquierdo et al 1998; Topalan et al 2003; Selvaggi et al 2004; Garcia et al 2017). These changes can cause increased risks for thrombosis and organ dysfunction (Endean et al 1989; Bilgin et al 2003; Selvaggi et al 2004; Chesnutt and Han 2011).…”

Haemodynamic Recovery Properties of the Torsioned Testicular Artery Lumen

“…Torsional buckling is a common configuration that is generated due to the relative twist of vessel ends 8 . Likewise, a topologically C-shaped buckling is also likely when the internal pressure of vessel segments exceeds a mechanical limit 9 .…”