Experimental endocarditis in rabbits. I. Technique and spontaneous course of non-bacterial thrombotic endocarditis.

Insertion of a polyethylene catheter into the heart was used for regular establishment of sterile endocarditis in 52 rabbits. The catheter was inserted with the aid of guide wire, and distance marking on the catheter was used to obtain precise positioning, so that the catheter was retained with the curved distal end inside the left ventricle of the heart. The results showed that the catheterization procedure could be carried out with a high degree of accuracy. Uniform localization of the vegetations was obtained, these reaching a suitable size of development in all rabbits after insertion of the catheter for 3 days. Histological examination of the sterile vegetation showed that catheter withdrawal at this time would still permit the regular development of an infection. After withdrawal of the catheter, the sterile vegetations rapidly decreased in size and disappeared almost completely by 10 days. Sterile endocarditis in rabbits induced by a catheter for a period of 3 days proved to be a harmless and self-limiting disease. The model presented seems to be suitable for futher investigations on experimental bacterial endocarditis.