Novel compliant and tissue-permeable microporous polyurethane vascular prosthesis fabricated using an excimer laser ablation technique
✍ Scribed by Doi, Kiyoshi ;Nakayama, Yasuhide ;Matsuda, Takehisa
- Book ID
- 102654029
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 776 KB
- Volume
- 31
- Category
- Article
- ISSN
- 0021-9304
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✦ Synopsis
A small-diameter vascular prosthesis with a multiply pored structure could have great potential to elevate the patency rate, for the following two reasons: 1 ) increased flexibility of the graft may increase compliance matching, consequently minimizing intimal hyperplasia; and 2 ) enhanced transmural tissue ingrowth may accelerate endothelialization. In this study, we fabricated a polyurethane (PU)-based artificial graft with well-controlled micropores in terms of their diameter and distribution, which was achieved using a computeraided excimer laser (KrF) ablation technique. Three types of microporous PU tubes ( 2 mm in internal diameter, 100 pm in wall thickness) were designed: pore size (100 pm) and longitudinal pore-to-pore distance (200 pm) were constant, and circumferential pore-to-pore intervals were 60" (type l), 30" (type 2), and 15" (type 3). The fabricated prostheses were coated with photoreactive gelatin, which was photogelled and chemically fixed on PU surfaces upon ultraviolet light irradiation.
Scanning electron microscopy showed that pore size and arrangement were precisely controlled as designed, and that a gelatinous hydrogel layer was formed over the entire luminal surface. The stiffness parameter (p), inversely related to compliance, was determined from the change in external diameter against intraluminal pressure. An increase in the number of pores around the circumference decreased the p value. The type 3 graft, the stiffness parameter of which was very close to that of human coronary artery, was the most compliant among the three types. The combination of excimer laser-directed microporing and photochemical surface processing techniques enabled the development of a novel compliant small-caliber vascular prosthesis, which is expected to show enhanced transmural tissue ingrowth in vivo.