Novel embalming solution for neurosurgical simulation in cadavers.

OBJECT Surgical simulation using postmortem human heads is one of the most valid strategies for neurosurgical research and training. The authors customized an embalming formula that provides an optimal retraction profile and lifelike physical properties while preventing microorganism growth and brain decay for neurosurgical simulations in cadavers. They studied the properties of the customized formula and compared its use with the standard postmortem processing techniques: cryopreservation and formaldehyde-based embalming. METHODS Eighteen specimens were prepared for neurosurgical simulation: 6 formaldehyde embalmed, 6 cryopreserved, and 6 custom embalmed. The customized formula is a mixture of ethanol 62.4%, glycerol 17%, phenol 10.2%, formaldehyde 2.3%, and water 8.1%. After a standard pterional craniotomy, retraction profiles and brain stiffness were studied using an intracranial pressure transducer and monitor. Preservation time-that is, time that tissue remained in optimal condition-between specimen groups was also compared through periodical reports during a 48-hour simulation. RESULTS The mean (± standard deviation) retraction pressures were highest in the formaldehyde group and lowest in the cryopreserved group. The customized formula provided a mean retraction pressure almost 3 times lower than formaldehyde (36 ± 3 vs 103 ± 14 mm Hg, p < 0.01) and very similar to cryopreservation (24 ± 6 mm Hg, p < 0.01). For research purposes, preservation time in the cryopreserved group was limited to 4 hours and was unlimited for the customized and formaldehyde groups for the duration of the experiment. CONCLUSIONS The customized embalming solution described herein is optimal for allowing retraction and surgical maneuverability while preventing decay. The authors were able to significantly lower the formaldehyde content as compared with that in standard formulas. The custom embalming solution has the benefits from both cryopreservation (for example, biological brain tissue properties) and formaldehyde embalming (for example, preservation time and microorganism growth prevention) and minimizes their drawbacks, that is, rapid decay in the former and stiffness in the latter. The presented embalming formula provides an important advance for neurosurgical simulations in research and teaching.

[1]  P. Mertens,et al.  Latex Injection of Cadaver Heads: Technical Note , 2010, Neurosurgery.

[2]  Hugues Duffau,et al.  New Insights Into the Anatomic Dissection of the Temporal Stem With Special Emphasis on the Inferior Fronto‐occipital Fasciculus: Implications in Surgical Approach to Left Mesiotemporal and Temporoinsular Structures , 2010, Neurosurgery.

[3]  Jon Olabe,et al.  Human cadaver brain infusion model for neurosurgical training. , 2009, Surgical neurology.

[4]  Antonio Bernardo,et al.  A Three-dimensional Interactive Virtual Dissection Model to Simulate Transpetrous Surgical Avenues , 2003, Neurosurgery.

[5]  A. Friedman,et al.  Fiber dissection technique: lateral aspect of the brain. , 2000, Neurosurgery.

[6]  M. C. Whitehead,et al.  Evaluation of methods to reduce formaldehyde levels of cadavers in the dissection laboratory , 2008, Clinical anatomy.

[7]  M. Yașargil,et al.  New laboratory model for neurosurgical training that simulates live surgery. , 2002, Journal of neurosurgery.

[8]  R. Hayes,et al.  Mortality from solid tumors among workers in formaldehyde industries: an update of the NCI cohort. , 2013, American journal of industrial medicine.

[9]  Albert L. Rhoton,et al.  THREE‐DIMENSIONAL MICROSURGICAL AND TRACTOGRAPHIC ANATOMY OF THE WHITE MATTER OF THE HUMAN BRAIN , 2008 .

[10]  Peder Wolkoff,et al.  Cancer effects of formaldehyde: a proposal for an indoor air guideline value , 2010, Archives of Toxicology.

[11]  D. Kriebel,et al.  Reversible pulmonary responses to formaldehyde. A study of clinical anatomy students. , 1993, The American review of respiratory disease.

[12]  C. Ong,et al.  Medical students' exposure to formaldehyde in a gross anatomy dissection laboratory. , 1992, Journal of American college health : J of ACH.

[13]  K. Konecny,et al.  Characterizing formaldehyde emission rates in a gross anatomy laboratory. , 2001, Applied occupational and environmental hygiene.

[14]  Sebastian Kuhn,et al.  Influence of formalin fixation on the biomechanical properties of human diaphyseal bone , 2010, Biomedizinische Technik. Biomedical engineering.

[15]  J A Swenberg,et al.  Carcinogenicity of formaldehyde in rats and mice after long-term inhalation exposure. , 1983, Cancer research.

[16]  T. Menovsky.  A human skull cast model for training of intracranial microneurosurgical skills , 2000, Microsurgery.

[17]  Juan Alvarez-Linera,et al.  THREE‐DIMENSIONAL MICROSURGICAL AND TRACTOGRAPHIC ANATOMY OF THE WHITE MATTER OF THE HUMAN BRAIN , 2008, Neurosurgery.

[18]  P. Gloor.  Atlas cerebri humani. The inner structure of the brain , 1957 .

[19]  H. van Loveren,et al.  Colored silicone injection for use in neurosurgical dissections: anatomic technical note. , 1999, Neurosurgery.