Morphological and immunohistochemical changes in the liver in coarctation of the aorta during compensation and decompensation stages.

Compensated coarctation of the aorta is accompanied by a decrease in the tone of hepatic vessels, thinning of the vascular walls, and moderate expression of α-SMA. Bundles of intimal muscles, myoelastic sphincters, and polyp-like pads form in the arteries; the muscle rolls in the efferent veins degenerate. Hepatocyte changes are presented by focal involvement of the organelles. Decompensated coarctation is characterized by more pronounced atrophy of hepatic vascular walls and regulatory structures. The expression of α-SMA in the arteries increases, sclerosis develops, and signs of CD34 expression in the sinusoids and perisinusoidal fibrosis emerge. All these shifts are associated with coarse ultrastructural changes in hepatocytes.