QUANTITATIVE MORPHOLOGICAL EVALUATION OF STRUCTURAL RECONSTRUCTION OF ARTERIES OF JEJUNUM AT POSTRESECTION PORTAL HYPERTENSION

Abstract

Liver resection is widely used in modern surgical departments. Removal of large sizes of the liver leads to postresection portal hypertension, which is complicated by bleeding from varicose veins of the esophagus, stomach, rectum, ascites, splenomegaly with secondary hyperpselinism, parenchymal jaundice and portosystemic encephalopathy. The widespread prevalence of this pathology, high mortality from its complications indicates that it is an important medical and social problem.

The aim of the study – quantitative morphological study of the features of the structural reconstruction arteries of jejunum after postresection portal hypertension.

Materials and Methods. The studies were conducted on 36 sexually mature male rats, which were divided into 3 groups. The group 1 consisted of 12 intact virtually animals, 2 – 12 rats after resection of the left lateral part – 31.5 % of the parenchyma of the liver, 3 – 12 rats after removing of the right and left lateral portions of the liver (58.1 %). Euthanasia of experimental animals was carried out by bloodletting in conditions of thiopental anesthesia 1 month after the beginning of the experiment. From the jejunum histological preparations were made. The morphometry of arteries of middle (51–125) microns and small calibers (26–50) microns of jejunum was measured, in which their external and internal diameters, the thickness of the media and adventitia, the height of the endothelial cells, the diameter of their nuclei were determined the Wogenworts index, the nuclear-cytoplasmic rations in the endothelial cells and the relative volume of damaged endothelial cells. Quantitative indicators were processed statistically.

Results and Discussion. It was established that after resection of 31.5 % of the liver parenchyma, the morphometric indices of the arteries of the middle and small arteries of the jejunum were insignificantly changed. When removing 58.1 % of liver parenchyma, a marked structural reconstruction of the arterial bed with the predominance of morphological changes in the arteries of small caliber. One month after the removing of 58.1 % of the liver parenchyma, the outer diameter of the small caliber arteries increased by 2.0 %, the thickness of the media – by 16.7 %, the thickness of the adventitia – by 34.5 %, the Wogenworts index – 1.4 times, indicating on a significant structural reconstruction of the examined vessels. The inner diameter of small-caliber arteries with a significant statistical significance (p<0.001) decreased by 16.1 %. The height of the endothelial cells of the vessels was changed by 9.6 %, and their nuclei – by 5.4 % (p<0.01). The nuclear-cytoplasmic relations in the endothelial cells of the studied arteries were significantly disturbed, indicating a violation of cellular structural homeostasis, while the relative volume of damaged endothelial cells increased by 23.4 times. The studies shows the significantly remodeling of the arteries of the jejunum after the removing of 58.1 % of the parenchyma of the liver, which leads to deterioration of blood supply to the organ, hypoxia, dystrophy, necrobiosis of cells and tissues, and later infiltrative and sclerotic processes.

Conclusions. Resection of 58.1 % of liver parenchyma leads to postresection portal hypertension and marked structural reconstruction of middle and small caliber arteries of the jejunum, which was characterized by thickening of their walls, narrowing of the lumen, endothelial cell lesion, endothelial dysfunction, deterioration of blood supply to the organ, hypoxia, dystrophy, necrobiosis of cells and tissues, focal cell infiltrates, and sclerosis. The degree of structural reconstruction of arteries of the jejunum after postresection portal hypertension depends on their caliber and the most pronounced was found in investigated vessels of small caliber.