Cryodehydration protocol to obtain high‐quality permanent anatomical material

Abstract

The study of anatomy is largely dependent on cadaveric specimens to fulfill the tridimensional comprehension of each structure as well as the relationship between organs. Given the difficult access to fresh anatomical specimens, the constant renovation of samples for research and educational purposes is unsustainable, beyond the ethical issues involved. The standard technique for preserving specimens involves fixation and later immersion in formaldehyde, which enables a good result, but also presents elevated carcinogenic potential. Therefore, safe and efficient preservation methods are mandatory for anatomical practices and investigations. An accessible and inexpensive alternative for specimen preservation is cryodehydration.Cryodehydrated specimens can be kept dry, with no final odor, reducing the use and exposure to formaldehyde. The objective of this study was to propose a simplified step-by-step cryodehydration protocol to obtain high-quality anatomical specimens.Through consecutive freezing and thawing cycles, cryodehydration caused a weight reduction of 60%-70% and allowed anatomical preservation, while maintaining the main morphological aspects of cavitary and parenchymatous organs, muscles, or even full-body sections. The final specimens presented high durability and can be maintained for decades, preserving all relevant anatomical features.

Efficacy of cryodehydration technique in preserving the gross and histoarchitectural details of goat visceral and musculoskeletal specimens

“…Previous studies have reported excellent outcomes in preserving the sliced canine head using the cryodehydration technique [16] . The cavitary and parenchymatous organs and muscular tissues can also be preserved in a near-natural state, according to study reports [2 , 16 , 20 ].…”

“…Therefore, the animal cadaver as well as its different anatomical segments (either fresh or preserved) are major parts of both the teaching and learning of veterinary anatomy [1] . These allow the students as well as the researchers to study each structure from three-dimensional aspects, as studied in living beings [2] . However, the decay of biological specimens is a major challenge faced in this process.…”

“…Cryodehydration is the key step of cryopreservation, where the animal cadaver as well as the anatomical specimens are dehydrated through repeated freezing and thawing, following formalin fixation [16] . It is a kind of dry preservation technique that produces very lightweight final specimens, free from any irritating odor, is easy to store and transport, and can be handled bare-handed [2] . The formalin solution used initially for tissue fixation is also removed in the next steps of washing and repeated freezing-thawing sessions, reducing the risks of chemical exposure-related health issues [2 , 16 ].…”

“…It is a kind of dry preservation technique that produces very lightweight final specimens, free from any irritating odor, is easy to store and transport, and can be handled bare-handed [2] . The formalin solution used initially for tissue fixation is also removed in the next steps of washing and repeated freezing-thawing sessions, reducing the risks of chemical exposure-related health issues [2 , 16 ]. Microrupture of the cell wall is an important phenomenon in the cryodehydration process as it facilitates fluid drainage to accomplish proper dehydration [17] .…”

“…It is noteworthy that the primary goal of biological specimen preservation is to study both the microscopic characteristics and the gross morphology of the specimen. However, the earlier studies focused only on the efficacy of the cryodehydration technique in preserving the gross morphological aspects of the specimens [2 , 16 ]. However, no investigation has yet been conducted on the efficacy of this technique in preserving the histoarchitectural details of different types of organs or tissues.…”