[In vivo and in vitro degradation of fibrin adhesives (studies in rats)].

The fibrin seal (FS) is of indisputed value for hemostasis and atraumatic tissue synthesis in surgical therapy. In order to determine the optimal FS composition for resistance against fibrinolysis, in vivo lysis was tested by adding increasing amounts of the fibrinolysis-inhibitor aprotinine to 125I FS; urokinasis and plasminogen were administered in vitro while measuring protein and 125Iodine release. The correlation of protein and 125Iodine release clearly reflects the interdependence of both parameters; disjunction of radioactivity from the protein molecule was ruled out. In vitro, fibrinolysis is inhibited to a nearly unlimited extent by aprotinine. In vitro, aprotinine improves fibrinolysis inhibition only up to a maximum of 1500 KIE/ml clot, thereby significantly altering the maximum elimination of 125Iodine and FS half-life as well. Higher doses of aprotinine applied in vivo remain without effect upon FS stability. In human surgery, the addition of aprotinine to FS is recommended for strictly hemostyptic application only, but not for tissue synthesis such as nerve- and microvessel-anastomoses in plastic reconstructive surgery.