Mechanical response of human abdominal walls ex vivo: Effect of an incisional hernia and a mesh repair

Abstract

The design of meshes for the treatment of incisional hernias could benefit from better knowledge of the mechanical response of the abdominal wall and how this response is affected by the implant. The aim of this study was to characterise the mechanical behaviour of the human abdominal wall. Abdominal walls were tested ex vivo in three states: intact, after creation of a defect simulating an incisional hernia, and after reparation with a mesh implanted intraperitonally. For each state, the abdominal wall was subjected to air pressure loading. Local strain fields were determined using digital image correlation techniques. The strain fields on the internal and external surfaces of the abdominal wall exhibited different patterns. The strain patterns on the internal surface appeared to be related to the underlying anatomy of the abdominal wall. Higher strains were observed along the linea alba than along the perpendicular direction. Under pressure loading, the created incision increased the strain of the abdominal wall compared to the intact state in 5 cases of a total 6. In addition, the mesh repair decreased the strains of the abdominal wall compared to the incised state in 4 cases of 6. These results suggest that the intraperitoneal mesh restores at least partially the mechanical behaviour of the wall and provides quantification of the effects on the strains in various regions.

Abdominal wall muscle elasticity and abdomen local stiffness on healthy volunteers during various physiological activities

“…Numerous experimental studies were conducted to characterize ex vivo the mechanical response of the abdominal wall (Junge et al, 2001;Podwojewski et al, 2013Podwojewski et al, , 2014 or its components (Ben Abdelounis et al, 2013;Cooney et al, 2015;Förstemann et al, 2011;Grässel et al, 2005;Hollinsky and Sandberg, 2007;Kirilova et al, 2011;Korenkov et al, 2001;Lyons et al, 2014;Martins et al, 2012;Rath et al, 1996;Tran et al, 2014;Wolloscheck et al, 2004). However, in vivo examinations are required to take into consideration muscle activity and to study patterns of muscle activation during different tasks and postures using electromyography (Brown and McGill, 2010;Crommert et al, 2011;McCook et al, 2009;Urquhart et al, 2005;Vera-Garcia et al, 2007).…”

The ‘AbdoMAN’: an artificial abdominal wall simulator for biomechanical studies on laparotomy closure techniques

“…The use of 3D image stereo correlation in combination with a physiological biomechanical simulation model to analyze strain patterns and displacement in AW research was described before [ 23 , 28 , 29 ]. However, the combination with a dynamic simulation device has not been demonstrated yet, and provides insights into the biomechanics of the sutured AW.…”

Developing a new methodology to characterize in vivo the passive mechanical behavior of abdominal wall on an animal model

“…On the other side, some authors (Förstemann et al, 2011;Tran et al, 2014;Podwojewski et al, 2014) found a higher compliance in the longitudinal than in the transverse directions when performing in vitro and ex vivo tests of the whole abdominal muscle samples of human. Similar results were found in Song et al (2006) with the only in vivo experiment, according to author's knowledge, performed on abdominal human tissue.…”

“…when all components are working together, are needed to better determine its mechanical behavior. Particular highlights in this regard are Podwojewski et al (2014) and Tran et al (2014), who carried out ex vivo mechanical tests on human specimens considering the contribution of the different layers, and Song et al (2006) and Szymczak et al (2012), who performed in vivo tests measuring on a live human abdomen while this was subjected to different stresses. All these works, however, have some differences or limitations.…”

“…All these works, however, have some differences or limitations. Both Podwojewski et al (2014) and Tran et al (2014) works were based on ex vivo tests instead of in vivo, and defrosted human specimens were used without considering frozen effects on the mechanical response (Clavert et al, 2001;Giannini et al, 2008). Szymczak et al (2012) studied strains in some points of the specimen but stress was originated from muscle contraction, so active response of the muscle was studied there.…”