Prevention of retrosternal adhesions after pericardiotomy

Because repeat sternotomies are becoming much more prevalent with repeat coronary bypass operations, prevention of direct adhesions of the heart and grafts to the back of the sternum by use of synthetic or xenograft material to close the pericardiotomy has become a matter for investigation. In this study bovine and equine glutaraldehyde-processed xenografts were implanted bilaterally in dogs for implant intervals of 6 weeks and 3, 6, 9, and 12 months. The bovine and equine xenografts both performed well in resisting the adhesion of the heart to their inner surfaces and less well in resisting adhesion of the lung and chest wall to their outer surfaces. The bovine xenograft had a higher percentage of adhesion-free surface on all the surfaces evaluated; however, one of our 12-month bovine pericardial xenograft implants exhibited significant multifocal calcific degeneration. Although pericardial xenografts generally have performed well when implanted in the dog, Gallo, Artiñano, and Duran recently expressed concern about their performance in humans. Along with our finding of calcification, their concern suggests a cautious approach to clinical application.