Studies on preservation of gross pathological cardiac lesions by Thermocol plastination

Abstract

Demonstration of gross lesions for educational purposes is often based on wet specimens, preserved in formalin, that emit hazardous formaldehyde vapors. This study is a pioneering attempt to plastinate pathological lesions in animal tissues using the economical Thermocol instead of costly resins, viz. silicon, epoxy and polypropylene. Six bovine heart samples, showing pathological lesions, were fixed with 5% formol saline, followed by dehydration in pure acetone, and impregnation with 15% Thermocol in organic solvent. Finally, curing of specimens was undertaken using Touchwood. Three gross lesions of the heart, viz. myocardial cyst, fibrinous pericarditis and endocardial/ epicardial hemorrhages, were plastinated in the present study. The myocardial cyst could be fixed in seven days; the fibrinous pericarditis could be fixed in 10 days, whereas hemorrhages required 15 days for fixation. The heart samples were impregnated by 44-48 days. The color of the lesions became darker and prominent in the plastinated hearts. There was no change in the texture of the tissues due to plastination, whereas the consistency of the heart became harder compared to fresh heart tissue. There was an significant reduction in mean mass (42.95%) and mean volume (40%) in the plastinated specimens. The Thermocol plastinated specimens were non-toxic, dry, easy to handle, odourless and durable, without the disadvantages of traditional formaldehyde preservation.