Biomechanical Analysis of The Skin And Jejunum Of Dog Cadavers Subjected To A New Anatomical Preservation Technique For Surgical Teaching

Abstract

2Department of Biomechanics, Medicine and Rehabilitation of Locomotor System, College of Medicine, University of São Paulo (Usp), Ribeirão Preto, Brazil 3Department of Exact Sciences, São Paulo State University (Unesp), School of Agricultural and Veterinarian Sciences, Jaboticabal, São Paulo, Brazil ABSTRACT: Formaldehyde is a fixative and preservative widely used in anatomy laboratories, but it is harmful to health, and poses an environmental risk. Ethyl alcohol (EtOH) has also been used for effective fixation of bird muscles, and sodium chloride has been successfully tested for the preservation of anatomical parts for more than five years. The objective of this present study was to evaluate a new anatomical technique for teaching surgical techniques using dog cadavers fixed in EtOH, and preserved in a 30% aqueous solution of sodium chloride (ASSC). In addition, we aimed to determine the ideal time to stop the fixation, so that the skin and jejunum present biomechanical characteristics as close as possible to the control group of fresh animals. Five groups were used: a control group (fresh animals without fixation or conservation), and the other 4 groups which differed in the time of fixation in EtOH (30, 60, 90 and 120 days). Except for the controls, all groups were conserved in 30% ASSC for 120 days. Statistical analysis of variance (ANOVA) revealed no difference between treatments and times (P > 0.05) relative to the skin, and showed at least one time significantly different from the others (P < 0.01) in relation to the jejunum. The non-linear modeling test showed differences in the group fixed in EtOH for 30 days, suggesting that this was the best time period for fixing dog cadavers for use in surgical training.