Formolized Cadaveric Specimens Immersion‐Recovery Protocol

Abstract

Cadaveric dissection, promoted by multiple anatomists and institutions as a fundamental area of medical education and training , requires embalming of the bodies to disinfect and preserve them. Therefore, despite being a known toxic and carcinogenic agent, formaldehyde is still widely used for its characteristics and results. Our objective is to introduce a Formolized Cadaveric Specimens Immersion‐Recovery Protocol developed at our laboratory, the chemical reagents used, performed processes and results. The protocol consists on specimen’s immersion in an aqueous solution of potassium hydroxide (KOH) for its maceration, this process causes chemical reactions like lipids saponification and proteins breakdown. The immersion time varies from one specimen to another; however, KOH concentration should never exceed 10% (w/v), otherwise tissue hydrolysis may occur. After a profuse wash, oxidative degradation is carried out: oxidizing formaldehyde into H2O and CO2 through the degradation of hydrogen peroxide (H2O2). It is extremely important to avoid the contact of this agent with the previously used KOH, which would cause the decomposition of H2O2 into H2O, O2 and hydroxyls, without obtaining a proper formaldehyde oxidation. For this purpose, sodium hypochlorite can also be used, with variable results. To ignore this chemical basis limits the achievement of ideal results. This processes allow to obtain 60% more joint movement on goniometry measures compared with formolized specimens, with a change from grey color generated by formaldehyde to ocher. Likewise, the degradation of formaldehyde allows obtaining minimum levels of it in treated specimens, thus reducing health impact on those who handle the specimens. After the recovery process, our specimens were preserved with a low formaldehyde solution. Anatomy students were invited to a peer‐guided extracurricular activity, they interacted with both formolized and recovered specimens, and a likert questionnaire was used to evaluate their experiences with both techniques. Students referred that recovered specimens looked more realistic and considered them better to work with. They also mentioned recovered corpses had less sensory hassles, like eye watering, airway irritation and coughing. Previous studies have compared Thiel solution and formaldehyde fixation. Thiel‐preserved bodies are considered to be a better choice on dissection and surgical training, since tissues offer a more realistic experience. Nonetheless, this technique has disadvantages such as higher costs, vacuum conservation, and the need of trained personal to handle the specimens. Moreover, some chemicals and infrastructure are not available worldwide. An example of the former scenario is present with Ammonium Nitrate, key component in Thiel’s, which is strictly regulated in several countriesSupport or Funding InformationAnatomy Laboratory, Universidad de Los Andes, School of Medicine