Morphological Changes Induced in the Liver by Acute Passive Congestion.

Abstract

This is a continuation of the experimental work on the liver of the dog begun by Doctor Simonds and Doctor Brandes. 1 , 2 , 3 , 4 , 5

The morphological changes induced in the liver by acute passive congestion lasting from 10 to 30 minutes, are being studied. The slides are taken from the same animals used in the above experiments with some additional ones from dogs in which a detailed study of blood and lymph changes was not made.

The method of producing acute passive congestion has been described in the preceding papers. Briefly, it consists in producing mechanical constriction of the hepatic veins between the liver and the diaphragm by clamping with an intestinal clamp or by placing rubber tubing about these veins, anterior to and excluding the inferior vena cava. With the veins constricted, the liver can be seen to enlarge and darken, and the veins in the mesentery can be seen to dilate while the intestine assumes a bluish color.

After 10 to 30 minutes, the constriction is released, and the laparotomy wound is closed. All the work is done aseptically under ether anesthesia.

The dogs are then killed at intervals of 12 to 72 hours with ether. Some of the last dogs have been allowed to live 1 week. After autopsy, sections from several lobes of the liver are prepared routinely.

In studying these slides, an attempt is being made to estimate the amount of damage done. This is being done by comparing the area of the tissue which seems little if at all damaged, with the total area of the portion of the section examined microscopically. From 15 to 20 low power fields—measuring 1.3 mm. in diameter, or 1.327,326 sq. mm.—are studied per slide. The area of the normal tissue is computed arithmetically from measurements with a micrometer which fits in the eyepiece.