Gerinnungsveränderungen bei orthotoper Lebertransplantation am Hund

Abstract

ZusammenfassungBei 16 Hunden wurden bei orthotopen Auto- und Homotransplantationen der Leber Gerinnungsuntersuchungen durchgeführt. Während die Anästhesie, die Präparation der Lebergefäße und Manipulationen an Leber und Lunge keine Gerinnungsveränderungen hervorriefen, kam es nach Anlegen des äußeren venösen Bypass und Entnahme der Leber zu einem Abfall von Fibrinogen, Thrombozyten, Faktor II, Faktor VIII und Antithrombin III. Diese Veränderungen werden als Ausdruck einer Verbrauchskoagulopathie angesehen. Eine leichte Fibrinolyse war gewöhnlich erst am Ende der anhepatischen Phase nachweisbar und dürfte sekundär sein. Nach Implantation der Leber war nach kurzer Latenzzeit ein Wiederanstieg der oben genannten Faktoren und der Thrombozyten zu beobachten. Die möglichen Ursachen für das Auftreten der Verbrauchsreaktion werden diskutiert.

The Coagulation Disorder of Orthotopic Hepatic Transplantation

“…At the same time, the platelets in the dogs' blood showed aggregation and the morphologic changes of viscous metamorphosis, by electronmicroscopy, probably due to the action of generated thrombin. All these changes continued for 30 to 60 minutes after revascularization, but recovered thereafter if an adequately preserved liver had been transplanted [9,63]. Other investigators obtained similar findings in canine [69], porcine [70] and human [44,72] liver recipients.…”

“…The anhepatic phase. As a transient self-limited process during the anhepatic phase, intravascular coagulation was first demonstrated in dogs [9,63] by simultaneous decreases of platelets, fibrinogen, clotting factors II, V, VIII, X and antithrombin III, which, together with accelerated turnover rates of 51 Cr-thrombocytes and 125 I-fibrinogen, occurred maximally in the interval between exclusion of the recipient's liver from the circulation and completed vascularization of the donor liver. At the same time, the platelets in the dogs' blood showed aggregation and the morphologic changes of viscous metamorphosis, by electronmicroscopy, probably due to the action of generated thrombin.…”

“…Other investigators obtained similar findings in canine [69], porcine [70] and human [44,72] liver recipients. In some of the studies, the actual consumption of clotting factors was preceded by a hypercoagulable state, as indicated by elevated clotting factors, shortened plasma clotting times and increase of fibrin degradation products [9,72]. Administration of heparin in 2 human cases greatly diminished the consumption of clotting factors and secondary fibrinolysis [72].…”

“…From the cited clinical and experimental findings, it is evident that systemic fibrinolysis is transiently induced during orthotopic hepatic transplantation. However, its significance for the generation of coagulation changes and consecutive hemorrhages has been questioned by several investigators [9,34,70,91]. It has been emphasized, for instance, that the observed increase of fibrinolysis in human liver recipients usually is moderate in degree, and increases of plasminogen activator, possibly due to its transience, have been missed [34].…”

“…It has been emphasized, for instance, that the observed increase of fibrinolysis in human liver recipients usually is moderate in degree, and increases of plasminogen activator, possibly due to its transience, have been missed [34]. Furthermore, the low plasminogen and increased levels of fibrin degradation products found in the absence of significant plasminogen activator activity have been attributed rather to localized activation of fibrinolysis, secondary to intravascular coagulation [9,34,44,63,72].…”