[An experimental study of small-caliber tissue engineering vessels with acellular matrix].

Objective: To observe the mechanical properties of the prefabricated connective tissue tube as blood vessel substitute and its changes after implantation at the femoral artery.

Methods: The acellular matrix tube of 8-12 cm in length with a silicone rod inside it was implanted into dog peritoneal cavity. 3 weeks later, a new formed tube around the silicone rod was transferred to the femoral artery as blood vessel substitute. The mechanical properties and histological examination of the blood vessel substitute were assessed and compared to those of the carotid artery and vein. 6 months after transfer, the patency of the blood vessels substitute was observed. The histological change was studied by light microscopy, scanning and transmitting electron microscopy.

Results: (1) The mechanical properties of blood vessel substitute was not as strong as artery, but better than the vein. (2) There were elastic and collagen fibers with many fibroblasts around the tube wall, but few mesothelial cells around the inner wall. All of the blood vessel substitutes (n = 6) were found to keep patency and the structure of the blood vessels substitutes became similar to femoral artery 6 months after they had been grafted to the femoral artery.

Conclusions: These results suggest that tissue engineering in vivo is a good approach to construct vessels substitute. The tissue tubes made in dog's peritoneal cavity have good condition when it is used as a blood vessel substitutes.