Polydioxanone and polypropylene suture material in free internal mammary artery graft anastomoses

An experimental study with six beagle dogs was conducted to evaluate a new monofilamentous absorbable suturing material--polydioxanone. Free internal mammary artery grafts, 3 cm long, were harvested via a median sternotomy and were implanted as arterial bypasses in femoral arteries (12 end-to-end anastomoses) and as arteriovenous shunts in the carotid artery-contralateral jugular vein position (12 end-to-side anastomoses). Twenty-four anastomoses were made with monofilamentous nonabsorbable suturing material, polypropylene (12 arterial, 12 shunts), to serve as control grafts. At 6 months the grafts and anastomoses were explanted and studied with light and scanning electron microscopes. Macroscopically, the polydioxanone sutures had disappeared. The major histologic finding was the foreign body reaction around the polypropylene sutures. In the electron microscopic study the endothelial line covered the anastomotic site and in the polypropylene anastomoses the suture material was bulging up from the anastomoses. No aneurysms or dilatations were seen. According to this study, polydioxanone is a suitable suturing material for small luminal arterial anastomoses and is superior to polypropylene suturing material because it causes no tissue or other late changes on the flow surfaces.