Effect of Splenectomy and of Other Surgical Procedures upon Circulating Blood Platelets (Rabbits).

Abstract

It is a well established fact that splenectomy in the normal animal is usually followed by a considerable increase in the number of blood platelets. Largely on the basis of this fact the theory of the thrombolytic function of the spleen has been generally adopted. This theory was supported by the clinical observation of Kaznelson 1 that in purpura hemorrhagica, removal of the spleen was followed by an immediate increase of platelets and disappearance of purpuric hemorrhages. He assumed, therefore, that in this disease there was an overwhelming destruction of platelets in the spleen and suggested the name “splenogenous thrombolytic purpura,” Most of the observational evidence in splenectomy in humans has supported Kaz-nelson's theory. Conclusions drawn from this kind of observation, however, are hazardous as there are so many unknown and uncontrollable factors involved.

Moreover, it has been frequently observed that platelets are increased in number after other operations. The results of extensive clinical observations of this kind were published by Dawbarn, Earlam and Evans, 2 Bachman and Hultgren 3 concluded from experiments on rabbits that all operative procedures involving considerable trauma to tissues are followed by an increase in blood platelets but that the thrombocytosis induced by splenectomy is greater and of longer duration. Liles 4 observed that a group of rabbits, each of which had been the recipient of a transplanted spleen, showed an even greater increase in platelets than a group from which the spleens had been removed. On the tenth day the 2 groups showed the same platelet level but the level was sustained for a longer time in the splenectomized animals than in the recipients. He attributed the initial rise in both groups to traumatism.