title: Submillimeter Diameter Poly(Vinyl Alcohol) Vascular Graft Patency in Rabbit Model.
abstract: Microvascular surgery is becoming a prevalent surgical practice. Replantation, hand reconstruction, orthopedic, and free tissue transfer procedures all rely on microvascular surgery for the repair of venous and arterial defects at the millimeter and submillimeter levels. Often, a vascular graft is required for the procedure as a means to bridge the gap between native arteries. While autologous vessels are desired for their bioactivity and non-thrombogenicity, the tedious harvest process, lack of availability, and caliber or mechanical mismatch contribute to graft failure. Thus, there is a need for an off-the-shelf artificial vascular graft that has low thrombogenic properties and mechanical properties matching those of submillimeter vessels. Poly(vinyl alcohol) hydrogel (PVA) has excellent prospects as a vascular graft due to its bioinertness, low thrombogenicity, high water content, and tunable mechanical properties. Here, we fabricated PVA grafts with submillimeter diameter and mechanical properties that closely approximated those of the rabbit femoral artery. In vitro platelet adhesion and microparticle release assay verified the low thrombogenicity of PVA. A stringent proof-of-concept in vivo test was performed by implanting PVA grafts in rabbit femoral artery with multilevel arterial occlusion. Laser Doppler measurements indicated the improved perfusion of the distal limb after implantation with PVA grafts. Moreover, ultrasound Doppler and angiography verified that the submillimeter diameter PVA vascular grafts remained patent for 2 weeks without the aid of anticoagulant or antithrombotics. Endothelial cells were observed in the luminal surface of one patent PVA graft. The advantageous non-thrombogenic and tunable mechanical properties of PVA that are retained even in the submillimeter diameter dimensions support the application of this biomaterial for vascular replacement in microvascular surgery.
authors.affiliation: Mechanobiology Institute, National University of Singapore, Singapore; Department of Biomedical Engineering, National University of Singapore, Singapore.
authors.forename: Marie F A
authors.initials: MF
authors.lastname: Cutiongco
authors.affiliation: Mechanobiology Institute, National University of Singapore , Singapore.
authors.forename: Marek
authors.initials: M
authors.lastname: Kukumberg
authors.affiliation: Comparative Medicine, National University of Singapore , Singapore.
authors.forename: Jonnathan L
authors.initials: JL
authors.lastname: Peneyra
authors.affiliation: Division of Plastic, Reconstructive and Aesthetic Surgery, Department of Surgery, National University Health System, Singapore; Plastic, Reconstructive and Aesthetic Surgery Section, Department of General Surgery, Tan Tock Seng Hospital, Singapore.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Yeo
authors.affiliation: Department of Biomedical Engineering, National University of Singapore , Singapore.
authors.forename: Jia Y
authors.initials: JY
authors.lastname: Yao
authors.affiliation: Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore , Singapore.
authors.forename: Abdul Jalil
authors.initials: AJ
authors.lastname: Rufaihah
authors.affiliation: INSERM, U791, Center for OsteoArticular and Dental Tissue Engineering, Université de Nantes , Nantes , France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Le Visage
authors.affiliation: Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Department of Cardiovascular and Thoracic Surgery, National University Health System, Singapore.
authors.forename: Jackie Pei
authors.initials: JP
authors.lastname: Ho
authors.affiliation: Mechanobiology Institute, National University of Singapore, Singapore; Department of Biomedical Engineering, National University of Singapore, Singapore; Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Department of Chemical Engineering, University of Waterloo, Waterloo, ON, Canada.
authors.forename: Evelyn K F
authors.initials: EK
authors.lastname: Yim
keywords: compliance matching; in vivo testing; microvascular graft; off-the-shelf vascular graft; small diameter vascular graft