Sequential studies of arterial wall regeneration in microporous, compliant, biodegradable small-caliber vascular grafts in XXXX .

@entity7049 @entity35 @entity850 @entity2636 @entity8233
Microporous, compliant, biodegradable vascular grafts prepared from a mixture of @entity2636 (95% weight) and @entity7049 (5% weight) can function as a temporary scaffold for the regeneration of the arterial wall in small-caliber arteries. This study was undertaken to document the sequential events leading to this regeneration. Therefore, @entity2636 / @entity7049 vascular grafts were implanted into the abdominal aorta of @entity35 (N = 28) and were harvested at regular intervals from 1 hour up to 12 weeks after implantation. The implants were evaluated by means of light and electron microscopy. At each time of harvesting, the implants were patent and showed arterial pulsations. No @entity850 or dilatation was observed. Endothelial cells grew from the adjacent aortic intima across the anastomoses, from day 6 onward, to form an almost complete @entity8233 after 6 weeks of implantation. Smooth muscle cells also grew from the adjacent aortic media over the graft lattice through the platelet-fibrin coagulum from day 6 onward. The smooth muscle cells, predominantly longitudinally arranged at week 6, but also circularly arranged in some areas at week 12, formed a neomedia in which elastic laminae regenerated. Polymorphonuclear leukocytes and monocytes initially invaded the graft lattices. Fibroblasts, histiocytes, and capillaries grew from the perigraft tissue into the @entity2636 / @entity7049 lattices from day 6 onward, which resulted in the formation of a neoadventitia. The @entity2636 / @entity7049 lattices started to disintegrate from day 12 onward. The regenerative processes in the disintegrating @entity2636 / @entity7049 grafts resulted in the formation of neoarteries, which were of sufficient strength, compliance, and thromboresistance to function as small-caliber arterial substitutes.
