The effect of preclotting on surface thrombogenicity and thromboembolic complications of Dacron grafts in the canine thoracic aorta

Previous reports have advocated preclotting and autoclaving of Dacron grafts to prevent graft hemorrhage, yet no data delineate possible changes in surface thrombogenicity or thromboembolic risks. To assess these factors, preclotted and preclotted-autoclaved woven Dacron prostheses were implanted in the thoracic aorta of 31 dogs. Grafts were harvested 1 week to 1 month following implantation, and the thrombus-free surface of each graft was calculated by computerized morphometry. Values for thrombus-free surface were lowest in autoclaved grafts preclotted in nonheparinized blood (72%) or in heparinized blood (78%). Grafts preclotted in platelet-rich plasma and autoclaved had a thrombus-free surface value of 85%. Regular preclotted grafts or grafts without preclotting had the greatest thrombus-free surface value (97% and 99%). Distal embolization to the kidneys was detected in seven of 31 animals (23%). No emboli were found in animals with grafts that were not preclotted or if grafts were preclotted with platelet-rich plasma and autoclaved. Thrombus-free surface values were lower (p less than 0.01) in grafts with embolic complications (71% versus 91%). These data suggest that, if the risk of severe bleeding in fully heparinized patients precludes the use of a woven Dacron graft without preclotting, autoclaving a graft preclotted with platelet-rich plasma appears to be the method of choice.