Abstract | BACKGROUND: Vascular grafts perform less well than autologous arterial or vein grafts. The purpose of this study was to evaluate the short-term performance of selectively biodegradable filament- wound vascular prostheses, comprising elastomeric poly( ether urethane) (Lycra) scaffolds and flexible, hydrophilic biodegradable coatings. MATERIALS AND METHODS: Two types of selectively biodegradable vascular grafts were manufactured, comprising a filament- wound Lycra scaffold, subsequently coated with a biodegradable poly( ethylene glycol)/ poly(lactic acid) ( PELA) block copolymer. The two types of grafts differed in both the overall porosity of the scaffold and the hydrophilicity of the biodegradable constituent. A 60-mm-long and 6-mm-diameter filament- wound and polytetrafluoroethylene (ePTFE) grafts were implanted as interposition prostheses, randomly, at the right- and left-side carotid arteries. RESULTS: Implantation studies proved the grafts to be patent and pulsatile for periods of up to 3 months. Increasing the scaffold porosity and enhancing the hydrophilicity of the biodegradable component improved both the transmural tissue ingrowth process and the vascularization of the prosthesis wall. Also, a well-adhered peripheral tissue and a thin, uniform intima and endothelial lining were obtained. All ePTFE graft controls, although patent, were rather stiff and nonpulsatile. A thick pseudointima, poorly attached to the prosthesis inner surface, was observed. The compliance of the wet grafts was significantly higher than in the dry state, stemming mainly from the water-plasticizing effect on the biodegradable component. The grafts explanted after a period of 6 weeks exhibited compliance only slightly lower than that of the wet grafts. After 12 weeks, however, the hoop compliance was 20% lower than that prior to implantation. At 100 mm Hg, for example, the original compliance of the wet graft was 2.5%/100 mm Hg decreasing to 2.0%/100 mm Hg after a 3-month implantation. The compliance reduction with implantation is attributed to the ingrowth of the perigraft tissue as revealed by the histological study. A compliance of 2.0%/100 mm Hg is slightly better than that of a standard PTFE graft with an original compliance of 1.6%/100 mm Hg. Yet it is still an order of magnitude smaller than that of a canine carotid artery. CONCLUSIONS: The improved mechanical properties and enhanced healing of the highly porous filament- wound Lycra scaffold graft coated with hydrophilic biodegradable PELA has the potential of being a highly effective small caliber prosthetic graft.
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Authors | U Izhar, H Schwalb, J B Borman, G R Hellener, A Hotoveli-Salomon, G Marom, T Stern, D Cohn |
Journal | The Journal of surgical research
(J Surg Res)
Vol. 95
Issue 2
Pg. 152-60
(Feb 2001)
ISSN: 0022-4804 [Print] United States |
PMID | 11162039
(Publication Type: Journal Article)
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Copyright | Copyright 2000 Academic Press. |
Chemical References |
- Lactates
- Polymers
- Polyurethanes
- polyethylene oxide-polylactic acid block copolymer
- Polyethylene Glycols
- Polytetrafluoroethylene
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Topics |
- Absorbable Implants
- Animals
- Blood Vessel Prosthesis
- Blood Vessel Prosthesis Implantation
- Carotid Artery, Common
- Cell Adhesion
- Dogs
- Endothelium, Vascular
(cytology, physiology)
- Lactates
(pharmacokinetics)
- Models, Animal
- Polyethylene Glycols
(pharmacokinetics)
- Polymers
(pharmacokinetics)
- Polytetrafluoroethylene
(pharmacokinetics)
- Polyurethanes
- Time Factors
- Tunica Intima
(cytology, physiology)
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