Comparison of Two Digestive Techniques for Preparation of Vascular Elastic Networks for SEM Observation

Abstract

Two digestion procedures are now available to expose and isolate networks of vascular elastic fibers for three‐dimensional SEM observation. This study was designed to observe and elucidate the differences between the two types of digestion (sodium hydroxide vs. formic acid) and the differences between the two types of dehydration (ethanol‐critical‐point drying vs. freeze drying) used in each procedure. Canine venous valve segments, containing delicate networks of elastic fibers, and femoral arteries, containing large elastic lamellae, were used to compare the effects of the digestion and dehydration procedures on two types of vessels with different content and organization of elastic tissue. Results indicated there was no significant difference in the architecture of the elastic networks of either vessel based on the method of digestion. The major architectural changes in the elastic networks occurred as a result of the dehydration procedure used following digestion. Freeze drying is probably the best for arterial specimens due to their prominent lamellae, which give added support to maintain their normal architecture. It is suggested that both methods of dehydration be used on corresponding venous specimens containing delicate elastic networks. In this way, the investigator can benefit from the advantages of each method and overcome their respective disadvantages to get a more accurate picture of the three‐dimensional architecture of these delicate networks.