Caliber and media thickness of intrahepatic arteries in a normal human liver. A morphometric study

Morphometrical data on the intrahepatic arterial wall were studied over a wide range of vascular diameters (100-1708 microns) in one human liver. The liver tissue containing Araldite-filled blood vessels was embedded in the water-soluble glycolmethacrylate (GMA). The calculation of the correction factor for the morphometric data obtained from 3 microns sections is described. The influence of formaldehyde fixation on the volume of the liver proves to be negligible. During dehydration a linear shrinkage of about 3% occurs. After infiltration and embedding in GMA only 1% of this shrinkage remains. During the drying phase about 4.3% further linear stretching occurs. No significant "residual compression factor" was found. Araldite plays a significant role in the retention of the dimensions of the liver specimen during histologic processing, while the dimensional changes of the Araldite itself are negligible. A positive linear correlation was found between the media thickness and the radius of the vessel. The physiological consequences are discussed. It is concluded that in the morphometric analysis of the arterial wall it is essential to apply a standardized procedure in histologic processing and in the measuring of the inner vascular diameter. The advantages of our method, in which blood vessels are perfused with Araldite under physiological pressure, are discussed.