Preserving haptic fidelity: How cadaveric preservation methods affect the biomechanical properties of abdominal wall tissues

Kyleigh Kriener, Raushan Lala, Ryan Homes, Kate Sinclair, Hayley Finely, Mark Midwinter

The School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, Australia

Objectives: Clinical procedural skills practice is commonly acquired in workshops using cadavers. These workshops help trainees appreciate the required forces that need to be applied to tissues to complete procedures effectively and safely. The forces trainees experience depends on the biomechanical properties of tissues. However, it is unclear how the various cadaveric preservation techniques (e.g., fresh, fresh-frozen, embalmed) affect the biomechanical properties of tissues. The objective of this research is to profile and compare the tensile properties of cadaveric abdominal wall tissues that have undergone different methods of preservation with a view to optimise training in laparoscopic port placement.
Methods: Abdominal wall tissue specimens were collected from fresh-never-frozen, fresh-frozen-thawed, and embalmed cadavers. Tissue specimens were loaded uniaxially in tension at a strain rate of 5 mm/min until tissue failure. Stress-strain curves were created to determine the elastic modulus, ultimate stress, and strains at failure.
Results: The mean elastic modulus and ultimate tensile strengths across all tissue types was highest (i.e., stiffest) in embalmed tissues. Embalmed tissue also did not deform as much as fresh-never-frozen and fresh-frozen tissues in the elastic region and at failure. Fresh-frozen tissues was generally stiffer and had a higher ultimate tensile strength than fresh-never-frozen tissues.
Conclusions: This work demonstrates that methods of preservation have an affect on tissues in the abdominal wall. Therefore, in settings where tissue must mimic live patients to a high degree (i.e., high haptic fidelity), fresh-never-frozen cadavers most likely mimic an alive patient more than other preservation methods.

Keywords: anterior abdominal wall; biomechanics; cadaveric tissues; preservation techniques; surgical training

Ethical statement: Ethical approval was obtained from the University of Queensland (2021/HE002373). All cadaveric work was preformed in line with the following acts: Transplantation and Anatomy, 1979 (Queensland), Transplantation and Anatomy Regulations, 2017 (Queensland), Criminal Code, 1899 (Queensland), and Work Health and Safety, 2011 (Queensland).

Funding statement: Funding for this work comes from the Australian Research Training Program and the Wellcome Leap SAVE program.