Abstract
We developed an in vivo method to evaluate biocompatibility of small-caliber vascular grafts. Expanded polytetrafluoro-ethylene (EPTFE, 2 and 3mm internal diameter) and other vascular prosthetic materials (2mm internal diameter) were placed in the carotid arteries of normal male rabbits, using a sleeve (end in end) anastomosis, where a cut end of the artery is everted over an external splint, inserted into the graft tube, and then fixed with a circumferential ligature. At early times after the substitution, blood- and tissue-compatibility of the materials was determined by scanning electron and light microscope examinations. Thrombus deposition at 5-120min, patency rate at 1-7 days, and healing characteristics at 4-8 weeks after the substitution of EPTFE were found to be comparable with our previous results obtained using the conventional (end to end) suture method. The relative order of patency rate on the tested materials was shown as follows: EPTFE≅porous polyethylene>polyethylene>polyurethane. These results indicate that the rabbit sleeve anastomosis method is easy to perform, reproducible and useful in the in vivo screening of small-caliber vascular grafts for their short-term thrombogenicity and subsequent healing properties.
