STUDIES IN EXPERIMENTAL EXTRACORPOREAL THROMBOSIS

Abstract

In experimental obstructive jaundice in rabbits, thrombosis is definitely delayed in the extracorporeal loop. White thrombi are laid down at the normal rate in many instances; in others there is a delay in deposition of platelets, while in still others cauliflower-like masses of platelets are rapidly deposited and tend to slow or even stop the blood stream before much fibrin is apparent. Fibrin deposits and formation of the red thrombus usually appear late in the experiment and often only at the ends of the collodion tubes. In vigorous animals, the thrombi rarely tend to obstruct and usually cease growing when they have made up the difference between the lumen of the glass tube and of the collodion tube. On the other hand, if the animal's general condition is poor and its circulation depressed, red thrombus forms more rapidly and tends to encroach progressively on the lumen until obstruction takes place. Even in such cases circulation through the loop persists for periods much longer than in the normal animal. Judging from the gross appearance of the thrombus the quantity and quality of fibrin seem deficient. Single injections of bile salts yield pictures similar to those seen in experimental obstructive jaundice. White thrombi are deposited but obstruction of the lumen is delayed because of inadequate formation of fibrin. The continuous intravenous injection of bile salts resulted in a progressive increase of the clotting time and in the level of bile acids of the blood. The state of the extracorporeal loop was likewise similar in many respects to that seen in obstructive jaundice. There was, however, a definite decrease in the size and numbers of white thrombi deposited on the collodion membrane. From the evidence presented it is obvious that the processes of blood coagulation and of thrombosis in the extracorporeal loop are definitely delayed in experimental obstructive jaundice and in animals that have received intravenous injections of bile salts. No attempt is made to explain the changes found in jaundice on the basis of the increased levels of bile acids in the blood although these experiments would indicate that such a possibility has not been ruled out.