Operative results of thyroidectomy and thymectomy in the rabbit.

Abstract

During the last two years, our study of animal resistance has included investigations on the endocrine mechanism as one of the factors involved in the reaction of the host to disease processes. 1 , 2 , 3 Operative procedures of various types have been carried out on the thyroid, thymus, and suprarenal glands of rabbits, and the majority of animals have been inoculated with Treponema pallidum or a malignant tumor of the rabbit 4 either before or after operation. The rabbits so operated upon have been kept under observation from three to ten months, and at the conclusion of the experiments a complete autopsy was carried out in each instance. In this communication we wish to present a summary of the operative results upon the thyroid and thymus from the point of view of operative mortality, wound infection, and the incidence of residual nodules of gland tissue.

Complete thyroidectomy has been performed in 103 instances with an operative mortality of 3.9 per cent (4 rabbits). These deaths occurred among our early operations and were attributed to over-anesthetization; in one instance there was an acute pulmonary emphysema. We have had no fatalities in the last 54 operations. The only case of wound infection occurred in the one animal in which local anesthesia was used and in which there was also an extensive mange. Up to the present time, 90 of the rabbits have been autopsied, and in four instances (4.4 per cent) tiny nodules of hyperplastic thyroid tissue have been found in close connection with a silk ligature.

A partial removal of the thyroid has been carried out in 30 rabbits. In 24 instances one lobe and the isthmus were removed while in six the operation included the ligation of the blood supply to the remaining lobe. There has been one operative death, or 3.3 per cent, and no instance of wound infection.