Fabrications of small diameter compliance bypass conduit using electrospinning of clinical grade polyurethane

Abstract

Objective Compliance and viscoelastic mismatches of small diameter vascular conduits and host arteries have been the cause of conduit’s failure. Methods To reduce these mismatches, the aim of this study was to develop and characterize a polyurethane conduit, which mimics the viscoelastic behaviors of human arteries. Electrospinning technique was used to fabricate tubular polyurethane conduits with similar properties of the human common carotid artery. This was achieved by manipulating the fiber diameter by altering the syringe flow rate of the solution. The mechanical and viscoelastic properties of the fabricated electrospun polyurethane conduits were, then, compared with commercially available vascular conduits, expanded polytetrafluoroethylene, polyethylene terephthalate (Dacron®) and the healthy human common carotid arteries. In addition, a comprehensive constitutive model was proposed to capture the visco-hyperelastic behavior of the synthetic electrospun polyurethanes, commercial conduits and human common carotid arteries. Results Results showed that increasing the fiber diameter of electrospun polyurethanes from 114 to 190 nm reduced Young’s modulus from 8 to 2 MPa. Also, thicker fiber diameter yielded in higher conduits’ viscosity. Furthermore, the results revealed that proposed visco-hyperelastic model is strongly able to fit the experimental data with great precision which proofs the reliability of the proposed model to address both nonlinear elasticity and viscoelasticity of the electrospun polyurethanes, commercial conduits and human common carotid arteries. Conclusions In conclusion, statistical analysis revealed that the elastic and viscous properties of 190 nm fiber diameter conduit are very similar to that of human common carotid artery in comparison to the commercial expanded polytetrafluoroethylene and Dacron® that are up to nine and seven times stiffer than natural vessels. Therefore, based on our findings, from the mechanical point of view, by considering the amount of Young’s modulus, compliance, distensibility and viscoelastic behavior, the fabricated electrospun polyurethane with fiber diameter of 189.6 ± 52.89 nm is an optimum conduit with promising potential for substituting natural human vessels.

Enhanced hemocompatibility and rapid magnetic anastomosis of electrospun small-diameter artificial vascular grafts

“…After suturing, incomplete sealing and enlargement of the anastomosis due to suture cutting led to a high leakage risk. Approaches like crosslinking, coating, blending, and reinforcement have been proposed to improve the compliance (Faturechi et al, 2019b;Furdella et al, Frontiers in Bioengineering and Biotechnology frontiersin.org 2021), but may also affect hemocompatibility, requiring optimization. Given these limitations, we propose magnetic anastomosis to address the inadequate compliance of electrospun AVGs.…”

“…However, electrospun AVGs have limited compliance compared to native vessels ( Faturechi et al, 2019a ). This makes the anastomosis difficult, increases the leakage risk at the anastomosis site, and impairs patency ( Tamimi et al, 2019 ; Jeong et al, 2020 ).…”

PLCL-TPU bi-layered artificial blood vessel with compliance matching to host vessel

“…As we all know, the greater the elasticity of the material, the higher the compliance of the artificial blood vessel. 8 Faturechi et al 9 used polyurethane and electrospinning techniques to prepare an artificial blood vessel with compliance very similar to that of the human common carotid artery. Jean-Marc Behr et al 10 evaluated the compliance of artificial blood vessels made from PLCL with different monomer ratios (0:100, 50:50, 70:30, and 85:15) and results showed that the compliance of artificial blood vessels varied with different monomer ratios.…”

A Computational Fluid Dynamics Study on Patient-Specific Bifurcated Carotid Artery

“…Even after accounting for body and neck size, age, and blood pressure, it was shown that women's carotid arteries are smaller. [14,15] Proof of concept studies for CFD analysis to detect atherosclerotic changes in intracranial aneurysms have been undertaken (in this cardio-vascular problem, a weakening of the wall of a cerebral artery or vein causes a localized dilation or ballooning of the blood vessel). [16] Detailed study was conducted concerning simulation of blood flow in patientspecific arteries, particularly revolving around different categories like viscosity models, flow type, flow parameters and type of solver used.…”