Virtual simulation of the biomechanics of the abdominal wall with different stoma locations

Abstract

An ostomy is a surgical procedure by which an artificial opening in the abdominal wall, known as a stoma, is created. We assess the effects of stoma location on the abdominal wall mechanics. We perform three-dimensional finite element simulations on an anatomy model which was generated on the basis of medical images. Our simulation methodology is entirely based on open source software. We consider seventeen different locations for the stoma incision (trephine) and we simulate the mechanical response of the abdominal wall when an intraabdominal pressure as high as 20 kPa is applied. We focus on factors related to the risk of parastomal hernia development such as the deformation experienced by the abdominal wall, the stress levels supported by its tissues and the corresponding level of trephine enlargement. No significant dependence was found between stoma location and the levels of abdominal wall deformations or stress supported by tissues, except for the case with a stoma located on the linea alba. Trephine perimeter and area respectively increased by as much as $$44\%$$ 44 % and $$85\%$$ 85 % . The level of trephine deformation depends on stoma location with considerably higher trephine enlargements found in stomas laterally located with respect to the rectus abdominis muscle.

A virtual simulation approach to assess the effect of trocar-site placement and scar characteristics on the abdominal wall biomechanics

“…The present geometry model, illustrated in Fig. 1 , is similar to the one used in our previous work 5 . It consists of external oblique (EO), internal oblique (IO), rectus abdominis (RA) and transverse abdominis (TR) muscles, as well as the linea alba (LA), which was considered with standard dimensions of 2 cm (i.e., without rectus diastasis) 12 .…”

“…Following our previous work 5 we assumed a linear elastic behavior of the AW tissues, where σ is the stress tensor, ε is the strain tensor, accounting for the relative deformation of tissues, and E is the elastic modulus. The specific E values for each tissue, together with the bibliographic source, are listed in Table 2 .…”

“…Finite element (FE) simulations may strengthen our understanding of how surgical wounds (SWs) alter the mechanical behavior of the abdominal wall (AW) 5 , 6 . Our key assumption is that the response of the AW to intra-abdominal pressure (IAP) sometime after surgery will depend on the mechanical properties of the tissue regrown at the surgical sites, that is, the tissue conforming the SWs, and the laparoscopy pattern used in the surgery.…”

Biomechanical stability of hernia-damaged abdominal walls

“…In addition, FEM has been used to examine the constitutive behaviour of various tissues in the AW 5 . More recently, holistic models based on FEM have been developed to simulate the biomechanics of AWs subjected to local weaknesses in various locations seeking to address challenging scenarios of hernia development [6][7][8][9] . For example, Tuset et al 9 concluded that intestinal stoma location has no significant impact on the resulting stress and strain distributions except when it is located in the linea alba.…”

“…More recently, holistic models based on FEM have been developed to simulate the biomechanics of AWs subjected to local weaknesses in various locations seeking to address challenging scenarios of hernia development [6][7][8][9] . For example, Tuset et al 9 concluded that intestinal stoma location has no significant impact on the resulting stress and strain distributions except when it is located in the linea alba. As a predictive modelling tool, FEM can complement clinical research and facilitate the surgeons' decisions.…”