Review of Polymeric Biomimetic Small-Diameter Vascular Grafts to Tackle Intimal Hyperplasia

Abstract

Small-diameter artificial vascular grafts (SDAVG) are used to bypass blood flow in arterial occlusive diseases such as coronary heart or peripheral arterial disease. However, SDAVGs are plagued by restenosis after a short while due to thrombosis and the thickening of the neointimal wall known as intimal hyperplasia (IH). The specific causes of IH have not yet been deduced; however, thrombosis formation due to bioincompatibility as well as a mismatch between the biomechanical properties of the SDAVG and the native artery has been attributed to its initiation. The main challenges that have been faced in fabricating SDAVGs are facilitating rapid re-endothelialization of the luminal surface of the SDAVG and replicating the complex viscoelastic behavior of the arteries. Recent strategies to combat IH formation have been mostly based on imitating the natural structure and function of the native artery (biomimicry). Thus, most recently, developed grafts contain a multilayered structure with a designated function for each layer. This paper reviews the current polymeric, biomimetic SDAVGs in preventing the formation of IH. The materials used in fabrication, challenges, and strategies employed to tackle IH are summarized and discussed, and we focus on the multilayered structure of current SDAVGs. Additionally, the future aspects in this area are pointed out for researchers to consider in their endeavor.

Multilayered blow-spun vascular prostheses with luminal surfaces in Nano/Micro range: the influence on endothelial cell and platelet adhesion

“…The main task of this ~ 560 µm thick intermediate layer was to ensure the appropriate mechanical properties, which are an important factor determining the success of grafts upon implantation. In vivo, blood vessels are constantly exposed to pulsatile pressure and undergo constant deformation [35], so the prostheses should be produced from highly elastic materials. Furthermore, differences in mechanical properties between the implanted prosthesis and the native vessel can lead to aneurysm formation [36] or anastomotic intimal hyperplasia [37].…”

Fabrication of Nanocomposites with High Elasticity and Strength for the Load-Bearing Layer of Small-Diameter Vascular Grafts

“…Poly­(dimethylsiloxane) (PDMS) is used in a wide array of biomedical applications, such as biocompatible substrates for cell behavior studies, medical/surgical implants, pacemaker encapsulants, catheters, in DNA sequencing, disease diagnostics, drug delivery, microfluidics, and biosensors due to its transparency, biocompatibility, chemical inertness, and nontoxicity . A range of fabrication techniques have been developed to obtain the structure that can render the required viscoelasticity such as electrospinning, knitting, three-dimensional (3D) printing, and solvent casting . One of the key challenges in producing small-diameter vascular grafts is replicating the complex mechanical behavior of a native artery.…”

Construction of Rapid Extracellular Matrix-Deposited Small-Diameter Vascular Grafts Induced by Hypoxia in a Bioreactor

“…2 Some of the most common cardiovascular diseases, including peripheral artery disease, cerebrovascular disease, coronary artery disease, and deep vein thrombosis, also require the intervention of SDVGs. 3 Despite most clinical needs, there are no commercially available SDVG products. Therefore, the development of SDVGs is urgently required, as these have a promising future.…”

“…According to the American Heart Association report, more than one million patients every year in the United States require small-diameter vascular graft (SDVG) transplantation because of lower limb ischemia . Some of the most common cardiovascular diseases, including peripheral artery disease, cerebrovascular disease, coronary artery disease, and deep vein thrombosis, also require the intervention of SDVGs . Despite most clinical needs, there are no commercially available SDVG products.…”