title: Biodegradable, thermoplastic polyurethane grafts for small diameter vascular replacements.
abstract: Biodegradable vascular grafts with sufficient in vivo performance would be more advantageous than permanent non-degradable prostheses. These constructs would be continuously replaced by host tissue, leading to an endogenous functional implant which would adapt to the need of the patient and exhibit only limited risk of microbiological graft contamination. Adequate biomechanical strength and a wall structure which promotes rapid host remodeling are prerequisites for biodegradable approaches. Current approaches often reveal limited tensile strength and therefore require thicker or reinforced graft walls. In this study we investigated the in vitro and in vivo biocompatibility of thin host-vessel-matched grafts (n=34) formed from hard-block biodegradable thermoplastic polyurethane (TPU). Expanded polytetrafluoroethylene (ePTFE) conduits (n=34) served as control grafts. Grafts were analyzed by various techniques after retrieval at different time points (1 week; 1, 6, 12 months). TPU grafts showed significantly increased endothelial cell proliferation in vitro (P<0.001). Population by host cells increased significantly in the TPU conduits within 1 month of implantation (P=0.01). After long-term implantation, TPU implants showed 100% patency (ePTFE: 93%) with no signs of aneurysmal dilatation. Substantial remodeling of the degradable grafts was observed but varied between subjects. Intimal hyperplasia was limited to ePTFE conduits (29%). Thin-walled TPU grafts offer a new and desirable form of biodegradable vascular implant. Degradable grafts showed equivalent long-term performance characteristics compared to the clinically used, non-degradable material with improvements in intimal hyperplasia and ingrowth of host cells.
authors.affiliation: Division of Biomedical Research, Medical University of Vienna, Austria; Ludwig Boltzmann Cluster for Cardiovascular Research, Vienna, Austria. Electronic address: helga.bergmeister@meduniwien.ac.at.
authors.forename: Helga
authors.initials: H
authors.lastname: Bergmeister
authors.affiliation: Division of Biomedical Research, Medical University of Vienna, Austria; Ludwig Boltzmann Cluster for Cardiovascular Research, Vienna, Austria.
authors.forename: Nargiz
authors.initials: N
authors.lastname: Seyidova
authors.affiliation: Division of Biomedical Research, Medical University of Vienna, Austria; Ludwig Boltzmann Cluster for Cardiovascular Research, Vienna, Austria.
authors.forename: Catharina
authors.initials: C
authors.lastname: Schreiber
authors.affiliation: Division of Biomedical Research, Medical University of Vienna, Austria; Ludwig Boltzmann Cluster for Cardiovascular Research, Vienna, Austria.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Strobl
authors.affiliation: Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria; Ludwig Boltzmann Cluster for Cardiovascular Research, Vienna, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Grasl
authors.affiliation: Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Walter
authors.affiliation: Surgical Research Laboratories - Cardiac Surgery, Department of Surgery, Medical University of Vienna, Austria.
authors.forename: Barbara
authors.initials: B
authors.lastname: Messner
authors.affiliation: Institute of Applied Synthetic Chemistry, Vienna University of Technology, Vienna, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Baudis
authors.affiliation: Institute of Chemical Technologies and Analytics, Vienna University of Technology, Vienna, Austria.
authors.forename: Sophie
authors.initials: S
authors.lastname: Fröhlich
authors.affiliation: Institute of Chemical Technologies and Analytics, Vienna University of Technology, Vienna, Austria.
authors.forename: Martina
authors.initials: M
authors.lastname: Marchetti-Deschmann
authors.affiliation: Institute of Applied Synthetic Chemistry, Vienna University of Technology, Vienna, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Griesser
authors.affiliation: Computational Image Analysis and Radiology Lab, Department of Radiology, Medical University of Vienna, Austria.
authors.forename: Matt
authors.initials: M
authors.lastname: di Franco
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Vienna, Austria; Centre of Excellence, High Field MR, Department of Radiology, Medical University of Vienna, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Krssak
authors.affiliation: Institute of Applied Synthetic Chemistry, Vienna University of Technology, Vienna, Austria.
authors.forename: Robert
authors.initials: R
authors.lastname: Liska
authors.affiliation: Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria; Ludwig Boltzmann Cluster for Cardiovascular Research, Vienna, Austria.
authors.forename: Heinrich
authors.initials: H
authors.lastname: Schima
mesh_terms: D020341:Absorbable Implants; D063566:Biodegradable Plastics / Q000737:chemistry*; D001807:Blood Vessel Prosthesis; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D008422:Materials Testing; D011140:Polyurethanes / Q000737:chemistry*
chemical_list: D063566:Biodegradable Plastics; D011140:Polyurethanes
keywords: Biodegradable; Electrospinning; Polyurethane; Vascular graft