| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1986: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1985: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Research Abstract |
The major important properties of vascular grafts are compliance, suitability and healing of neointimae. A high-porosity graft that is loosely woven or knitted satisfies the above described properties but has the problem of severe blood leakage through its wall, especially during the administration of anticoagulants. For this reason, the high-porous graft is not acceptable as a graft for the thoracic aorta or as a composit graft with a heart valve. Lately, low porosity grafts have become widely used for these purposes. In the low porosity grafts developed so far, however, there are problems such as difficulties in anastomosis because the surgical needle cannot penetrate the rigid, tightly woven, or knitted structure. Another serious problem with low-porosity graft is delayed and uneven endothelialization, because its dense texture does not provides enough sites at which this can occur. In order to eliminate these drawbacks, we have developed a new low porosity graft using ultrafine pol
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yester fibers (UFPF) with a diameter of 3um or less.
Thirty grafts (water porosity:100ml/ <cm^2> , diameter:8mm, length:5.7cm) have been implanted in the thoracic aorta of mongrel dogs for one to 255 days. For the control, the commercial vascular grafts (porosity:136ml/ <cm^2> ) fabricated from polyester fiber (20um in diameter) were evaluated in the similar manner. The UFPF graft was very pliable and found easy in suturing and handling. The histological studies on the implanted UFPF grafts revealed that the infiltration of fibroblasts into the interstices among the fibers was significantly accelerated and the capillary formation was also recognized even in the early stage and the endothelialization was completed in about 85 days, while in the control grafts, no infiltration of fibroblasts was observed in the later stage of the implantation. These findings suggest that the thinning of the fibers significantly enhanced both of the anchoring effect of the graft to the cells and of thed compatibility of the fibers to the cell, leading to the acceleration of healing process of the vascular grafts. Less
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