Experimental Characterisation of the Anisotropic Behaviour of the Different Tissue Layers of Human Abdominal Wall.

Incisional hernias are a common complication after abdominal surgery with an incidence of 5-25% in general population after laparotomy. It is therefore necessary to reduce the potential occurrence of abdominal hernia development. For this, understanding the mechanical behaviour of the different abdominal wall structures is important to develop good predictive models. Unfortunately, very few experimental studies have addressed the different structures of the abdominal wall. To gain a better understanding of their mechanical behaviour, samples were extracted from pigs (for protocol validation) and then from two abdominal human cadavers, with different orientations (vertical, horizontal or oblique) on the different tissues. The mechanical characterization was obtained from quasi-static uniaxial tensile tests. The results showed anisotropic behaviour depending on the location and orientation of the tissue, as well as the type of tissue (muscle, aponeurosis or peritoneum). Inter-individual variability was also demonstrated. This study highlights the heterogeneity of the biomechanical properties of the abdominal wall and provide new values and interpretations to help improve the development of new predictive numerical models.