Perfusion fixation of hepatic needle biopsies for scanning electron microscopy. A methodological study.

Perfusion fixation is essential for the examination of the hepatic microvasculature by scanning electron microscopy. No detailed study has previously been done on the perfusion of human hepatic needle biopsies. The present paper demonstrates two modifications of a simple technique by which needle biopsies can be perfused. Perfusion was performed either manually (n = 33) or with a constant perfusion pressure of 10-15 mm H2O (n = 54). No significant difference in the ultrastructural preservation was observed in the two groups. Manual perfusion, however, when done gently, was superior in cleaning the sinusoids, and thus larger areas could be investigated by this method. Topographical orientation was possible, allowing the identification of terminal hepatic veins and portal tracts.