Fibrin glue in coronary surgery

Abstract

Adjunctive application of fibrin sealant in coronary artery bypass graft (CABG) surgery has been established over years for various indications, such as bleeding from distal or proximal anastomoses, fixation of the bypass course, diffuse epicardial bleeding, sealing of the IMA-bed, and intrasternal application for profound bone marrow bleeding. Moreover, fibrin sealant has been used in surgical fields with diffuse bleeding, e.g. in cardiac re-operations, for pre-clotting of Dacron prostheses, in thoracic organ transplantation, aortic aneurysm surgery, and in complex congenital heart surgery. The publications of Gorler et al. (1) and Lamm et al. (2) from distinguished heart centers are presenting data showing an unfavorable risk—benefit relation based on safety issues after the application of Tissucol W Duo S in CABG surgery. Both papers assess a significantly higher 30-day mortality in patients with intraoperative application of fibrin glue proven by a retrospective comparative analysis including more than 2000 patients each. According to the results of both retrospective analyses mortality in the fibrin glue group was about 7% and thus significantly higher compared the control patients with about 3%. Supported by profound statistical analysis fibrin glue had the most confounding effect on mortality in covariate analysis. In concordance with experimental data it has beenspeculated thatfibrin glue may induce transmural coagulation and thrombosis of venous grafts. The results presented in both studies, which were conducted independently, are considered to be consistent when analyzing risk factors, precondition of the patients and outcome. It became evident that pre-operative risk factors (according to the adapted EUROSCORE used in Hannover) cannot explain the increased mortality rate of the Tissucol group. Furthermore, surgical technique, cardiopulmonary bypass time and aortic cross clamp time did not significantly differ between those patients who received Tissucol during surgery compared to those who did not. However, considering the retrospective character of data acquisition the conclusiveness of these investigations is reduced. Specific information regarding the indication for the application offibrin glue is lacking.In addition,important background information concerning the hemostatic condition of the patient at the time before, during and after CABG was not routinely investigated and therefore a comprehensive evaluation of the hemostaseological risk factors was not available. Use of fibrin glue can be also a marker for problem cases. At least in our setting, we do not use fibrin glue in routine fashion. However, fibrin glue is used both preventively and correctively for patients with particularly fragile tissues, for patients at risk for bleeding, for patients with graft kinking, etc. Hence, the fact that fibrin glue is used, tells us, that there were some problems. In consideration of the presented results and the lack of detailed information on the indication and usage of fibrin sealant in both retrospective studies, it seems necessary to perform a prospective analysis, which may allow a more reliable evaluation of the risk of the use of fibrin glue in CABG surgery. Furthermore, any study in this respect needs to address not only the indication for fibrin glue application but also the investigation on those parameters in the coagulation system, which are state of the art to elucidate the hemostaseological pathomechanism of this severe complica- tion described in this situation. After discussing the results of both studies experts in the field of cardiovascular surgery and hemostaseology have concluded that the way of application of fibrin glue may have a considerable impact on the increased mortality of those patients. They emphasized the need of further investigation and, moreover, a clarification of the description of the preparation and use of fibrin sealant has been requested. However, until there are no more detailed data available, every surgeon has to define an individual strategy for the application of fibrin glue in coronary surgery based on the existing studies from the Hannover and Munich group.