A new cardiac wall substitute made of Dacron fabric prosthesis sealed with autologous tissue fragments: comparative studies of neointima formation and bleeding resistant property against fibrinolysis phenomenon with those of a preclotted sealing graft.

A cardiac wall substitute made of a Dacron fabric prosthesis sealed with minced-autologous tissue fragments was developed. An animal study showed rapid neointima formation on the graft luminal surface and no bleeding problem under load test with tissue plasminogen activator (tPA) administration. To evaluate the efficacy of the sealing method, a special substitute that was sealed with tissue fragments in one half and preclotted with fresh blood in the other half was prepared. The grafts were implanted into the right ventricular outflow tract in 14 dogs. During a load test with administration of tPA intravenously, the preclotted area bled quite remarkably; however, the area sealed with tissue fragments did not bleed. Two weeks after implantation, red thrombus adhered on the preclotted area, while a white, glistening surface was noticed on the tissue fragments area. Light microscopical observation showed complete neointima formation in the tissue fragmented area but a thrombus layer in the preclotted area. These results indicated that the tissue fragmentation was a superior method compared with preclotting for creating a cardiac wall substitute.