Abstract
We examined the 87 autopsy cases for the thrombus induced by inserting various catheters for diagnosis or treatment in the veins or arteries. Organization of the thrombus is classified into fresh (I), organizing (II-a, II-b, II-c) and organized (III-a, III-b). Dating of the thrombus was determined by measuring the interval between the day of the catheterization and the day of the patient's death. The thrombi of the elder patients tend to be delayed in organization. It is speculated that the intimal thickening, poor in cellularity may be correlated to the delay of the organization. The process of the organization of the thrombus is mediated by covering by newly formed endothelial cells, and infiltration and proliferation of smooth muscle cells from the underlying intima or media into the thrombus. Cellularity is very low in the intima showing fibrous thickening in the aged. Therefore, the number of the smooth muscle cells and other cells concerned in the organization of the thrombus is small. Other factors, such as senescence of cells and smooth muscle cell proliferating factors may have influence on the delay of the organization also.
Fibrinolytic therapy for thrombosis has been widely used nowadays. We should take account of the stage of organization of the thrombus when we treat the thrombosis.
