Does modification of suture materials influence graft patency after bypass sugery? Heparin-coated sutures show low thrombogenicity

• Published in: The Thoracic and Cardiovascular Surgeon
• Main Authors: Kobba, J, Walker, T, Wendel, HP, Schlensak, C
• Format: Conference Proceeding
• Language: English
• Published: 23.01.2013
• ISSN: 0171-6425; 1439-1902
• DOI: 10.1055/s-0032-1332659

Aims: Successful revascularization and maintenance of graft patency are the key goals of bypass surgery. Up to 10 – 15% of all grafts are occluded within the first days after bypass surgery. Endothelial damage and procoagulatory activity of subendothelial structures are considered to play a vital role. Little attention was drawn to the thrombogenicity of the suture materials used. Material and methods: Two sutures (polypropylene [PP] and polyvinylidene fluoride [PVDF], size 8 – 0, OD ca. 80 µm), with and without a covalent heparin-coating were tested in an in-vitro perfusion model for their thrombogenicity (n = 12). Blood was taken from healthy volunteers. The experiments were carried out in normothermia (37 °C). Anticoagulation was 1 IU heparin/ml. After 120 min. of blood circulation the sutures were fixed with glutaraldehyde, "critical point" dried, and sputtered. Analyses were performed by scanning electron microscopy (SEM). Results: The uncoated sutures PP and PVDF showed a strong adhesion of polymer fibrin, entangled with activated and aggregated platelets and leucocytes. In contrast, nearly no fibrin or adhered platelets could be detected on the heparin-coated sutures. Conclusion: In this in-vitro investigation we were able to indenitfy reduced thrombogenicity of heparin-coated sutures as compared to non-coated PP or PVDF sutures. The role of reduced thrombogenicity of suture materials on graft patency need to be validated in further studies. We assume that heparin-coated sutures may reduce the incidence of early graft occlusion after bypass surgery.