1
|
Troka M, Szepietowska K, Lubowiecka I. Self-organising maps in the analysis of strains of human abdominal wall to identify areas of similar mechanical behaviour. J Mech Behav Biomed Mater 2024; 156:106578. [PMID: 38781775 DOI: 10.1016/j.jmbbm.2024.106578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 03/05/2024] [Accepted: 05/08/2024] [Indexed: 05/25/2024]
Abstract
The study refers to the application of a type of artificial neural network called the Self-Organising Map (SOM) for the identification of areas of the human abdominal wall that behave in a similar mechanical way. The research is based on data acquired during in vivo tests using the digital image correlation technique (DIC). The mechanical behaviour of the human abdominal wall is analysed during changing intra-abdominal pressure. SOM allow to study simultaneously three variables in four time/load steps. The variables refer to the principal strains and their directions. SOM classifies all the abdominal surface data points into clusters that behave similarly in accordance with the 12 variables. The analysis of the clusters provides a better insight into abdominal wall deformation and its evolution under pressure than when observing a single mechanical variable. The presented results may provide a better understanding of the mechanics of the living human abdominal wall. It might be particularly useful when selecting proper implants as well as for the design of surgical meshes for the treatment of abdominal hernias, which would be mechanically compatible with identified regions of the human anterior abdominal wall, and possibly open the way for patient-specific solutions.
Collapse
Affiliation(s)
- Mateusz Troka
- Faculty of Civil and Environmental Engineering, Gdańsk University of Technology, Gdańsk, Poland
| | - Katarzyna Szepietowska
- Faculty of Civil and Environmental Engineering, Gdańsk University of Technology, Gdańsk, Poland
| | - Izabela Lubowiecka
- Faculty of Civil and Environmental Engineering, Gdańsk University of Technology, Gdańsk, Poland.
| |
Collapse
|
2
|
Tuset L, López-Cano M, Fortuny G, López JM, Herrero J, Puigjaner D. A virtual simulation approach to assess the effect of trocar-site placement and scar characteristics on the abdominal wall biomechanics. Sci Rep 2024; 14:3583. [PMID: 38351278 PMCID: PMC10864383 DOI: 10.1038/s41598-024-54119-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 02/08/2024] [Indexed: 02/16/2024] Open
Abstract
Analyses of registries and medical imaging suggest that laparoscopic surgery may be penalized with a high incidence of trocar-site hernias (TSH). In addition to trocar diameter, the location of the surgical wound (SW) may affect TSH incidence. The intra-abdominal pressure (IAP) exerted on the abdominal wall (AW) might also influence the appearance of TSH. In the present study, we used finite element (FE) simulations to predict the influence of trocar location and SW characteristics (stiffness) on the mechanical behavior of the AW subject to an IAP. Two models of laparoscopy patterns on the AW, with trocars in the 5-12 mm range, were generated. FE simulations for IAP values within the 4 kPa-20 kPa range were carried out using the Code Aster open-source software. Different stiffness levels of the SW tissue were considered. We found that midline-located surgical wounds barely deformed, even though they moved outwards along with the regular LA tissue. Laterally located SWs hardly changed their location but they experienced significant variations in their volume and shape. The amount of deformation of lateral SWs was found to strongly depend on their stiffness. Trocar incisions placed in a LA with non-diastatic dimensions do not compromise its mechanical integrity. The more lateral the trocars are placed, the greater is their deformation, regardless of their size. Thus, to prevent TSH it might be advisable to close lateral trocars with a suture, or even use a prosthetic reinforcement depending on the patient's risk factors (e.g., obesity).
Collapse
Affiliation(s)
- Lluís Tuset
- Departament d'Enginyeria Informàtica i Matemàtiques, Universitat Rovira i Virgili, Av. Països Catalans 26, Tarragona, Catalunya, Spain
| | - Manuel López-Cano
- Abdominal Wall Surgery Unit, Department of General Surgery, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Gerard Fortuny
- Departament d'Enginyeria Informàtica i Matemàtiques, Universitat Rovira i Virgili, Av. Països Catalans 26, Tarragona, Catalunya, Spain
| | - Josep M López
- Departament d'Enginyeria Informàtica i Matemàtiques, Universitat Rovira i Virgili, Av. Països Catalans 26, Tarragona, Catalunya, Spain
| | - Joan Herrero
- Departament d'Enginyeria Química, Universitat Rovira i Virgili, Av. Països Catalans 26, Tarragona, Catalunya, Spain
| | - Dolors Puigjaner
- Departament d'Enginyeria Informàtica i Matemàtiques, Universitat Rovira i Virgili, Av. Països Catalans 26, Tarragona, Catalunya, Spain.
| |
Collapse
|
3
|
Karrech A, Ahmad H, Hamdorf JM. Biomechanical stability of hernia-damaged abdominal walls. Sci Rep 2023; 13:4936. [PMID: 36973304 PMCID: PMC10043288 DOI: 10.1038/s41598-023-31674-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Accepted: 03/15/2023] [Indexed: 03/29/2023] Open
Abstract
Hernia occurs when the peritoneum and/or internal organs penetrate through a defect in the abdominal wall. Implanting mesh fabrics is a common way to reinforce the repair of hernia-damaged tissues, despite the risks of infection and failure associated with them. However, there is neither consensus on the optimum mesh placement within the abdominal muscles complex nor on the minimum size of hernia defect that requires surgical correction. Here we show that the optimum position of the mesh depends on the hernia location; placing the mesh on the transversus abdominis muscles reduces the equivalent stresses in the damaged zone and represents the optimum reinforcement solution for incisional hernia. However, retrorectus reinforcement of the linea alba is more effective than preperitoneal, anterectus, and onlay implantations in the case of paraumbilical hernia. Using the principles of fracture mechanics, we found that the critical size of a hernia damage zone becomes severe at 4.1 cm in the rectus abdominis and at larger sizes (5.2-8.2 cm) in other anterior abdominal muscles. Furthermore, we found that the hernia defect size must reach 7.8 mm in the rectus abdominis before it influences the failure stress. In other anterior abdominal muscles, hernia starts to influence the failure stress at sizes ranging from 1.5 to 3.4 mm. Our results provide objective criteria to decide when a hernia damage zone becomes severe and requires repair. They demonstrate where mesh should be implanted for a mechanically stable reinforcement, depending on the type of hernia. We anticipate our contribution to be a starting point for sophisticated models of damage and fracture biomechanics. For example, the apparent fracture toughness is an important physical property that should be determined for patients living with different obesity levels. Furthermore, relevant mechanical properties of abdominal muscles at various ages and health conditions would be significant to generate patient specific results.
Collapse
Affiliation(s)
- Ali Karrech
- School of Engineering, University of Western Australia, Perth, Australia.
| | - Hairul Ahmad
- UWA Medical School, University of Western Australia, Perth, Australia
- Perth Hernia Institute, Murdoch, Australia
| | - Jeffrey M Hamdorf
- UWA Medical School, University of Western Australia, Perth, Australia
- Perth Hernia Institute, Murdoch, Australia
| |
Collapse
|
4
|
Marcé-Nogué J. One step further in biomechanical models in palaeontology: a nonlinear finite element analysis review. PeerJ 2022; 10:e13890. [PMID: 35966920 PMCID: PMC9373974 DOI: 10.7717/peerj.13890] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 07/21/2022] [Indexed: 01/19/2023] Open
Abstract
Finite element analysis (FEA) is no longer a new technique in the fields of palaeontology, anthropology, and evolutionary biology. It is nowadays a well-established technique within the virtual functional-morphology toolkit. However, almost all the works published in these fields have only applied the most basic FEA tools i.e., linear materials in static structural problems. Linear and static approximations are commonly used because they are computationally less expensive, and the error associated with these assumptions can be accepted. Nonetheless, nonlinearities are natural to be used in biomechanical models especially when modelling soft tissues, establish contacts between separated bones or the inclusion of buckling results. The aim of this review is to, firstly, highlight the usefulness of non-linearities and secondly, showcase these FEA tool to researchers that work in functional morphology and biomechanics, as non-linearities can improve their FEA models by widening the possible applications and topics that currently are not used in palaeontology and anthropology.
Collapse
Affiliation(s)
- Jordi Marcé-Nogué
- Department of Mechanical Engineering, Universitat Rovira i Virgili Tarragona, Tarragona, Catalonia, Spain,Institut Català de Paleontologia, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Catalonia, Spain
| |
Collapse
|
5
|
Tuset L, López-Cano M, Fortuny G, López JM, Herrero J, Puigjaner D. Virtual simulation of the biomechanics of the abdominal wall with different stoma locations. Sci Rep 2022; 12:3545. [PMID: 35241748 PMCID: PMC8894338 DOI: 10.1038/s41598-022-07555-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 02/10/2022] [Indexed: 11/09/2022] Open
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 [Formula: see text] and [Formula: see text]. 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.
Collapse
Affiliation(s)
- Lluís Tuset
- Departament d'Enginyeria Informàtica i Matemàtiques, Universitat Rovira i Virgili, Av Països Catalans 26, Tarragona, Catalunya, Spain
| | - Manuel López-Cano
- Abdominal Wall Surgery Unit, Department of General Surgery, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Gerard Fortuny
- Departament d'Enginyeria Informàtica i Matemàtiques, Universitat Rovira i Virgili, Av Països Catalans 26, Tarragona, Catalunya, Spain.
| | - Josep M López
- Departament d'Enginyeria Informàtica i Matemàtiques, Universitat Rovira i Virgili, Av Països Catalans 26, Tarragona, Catalunya, Spain
| | - Joan Herrero
- Departament d'Enginyeria Química, Universitat Rovira i Virgili, Av Països Catalans 26, Tarragona, Catalunya, Spain
| | - Dolors Puigjaner
- Departament d'Enginyeria Informàtica i Matemàtiques, Universitat Rovira i Virgili, Av Països Catalans 26, Tarragona, Catalunya, Spain
| |
Collapse
|
6
|
Kirilova-Doneva M, Pashkouleva D. The effects of age and sex on the elastic mechanical properties of human abdominal fascia. Clin Biomech (Bristol, Avon) 2022; 92:105591. [PMID: 35131681 DOI: 10.1016/j.clinbiomech.2022.105591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 12/19/2021] [Accepted: 01/28/2022] [Indexed: 02/07/2023]
Abstract
BACKGROUND The abdominal hernias become more prevalent with age, that can adversely affect life quality. The mechanical properties of abdominal wall layers are supposed to play a significant role in developing of an abdominal hernia.The objective of this study was to determine the mechanical properties of the human abdominal layer - fascia and the effects of age and sex on it for choosing the proper brand of hernia mesh. METHODS 78 samples harvested from 19 fresh cadavers were subjected to uniaxial tension tests and divided into four groups according to age. Group A corresponds to age up to 60 years, Group B to age 61-70 years, Group C to age 71-80 years and Group D to 81-90 years. Median stress-stretch ratio curves with respect to age, sex and direction of loading were obtained. Median values of the maximum tensile stress, stretch at maximum stress and elastic modulus calculated at 5% strain were determined. FINDINGS The abdominal fascia showed large variations between specimens depending on age and sex. The stiffness of the fascia increased with age. There is statistically significant differences between the median curves of male samples (P = 0.008) and female samples (P = 0.019) according to age in the L direction. Statistically significant differences between the values of maximum stress (P = 0.01) and elastic modulus (P = 0.003) from Group C in the L direction and maximum stress (P = 0.03) from Group D in the T direction was established. INTERPRETATION The female samples are stiffer than male samples especially after 80 years.
Collapse
Affiliation(s)
- Miglena Kirilova-Doneva
- Faculty of Pharmacy, Medical University-Sofia, Sofia, Bulgaria; Institute of Mechanics, Bulgarian Academy of Sciences, Sofia, Bulgaria.
| | | |
Collapse
|
7
|
A novel in vivo approach to assess strains of the human abdominal wall under known intraabdominal pressure. J Mech Behav Biomed Mater 2021; 125:104902. [PMID: 34717119 DOI: 10.1016/j.jmbbm.2021.104902] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 10/11/2021] [Accepted: 10/13/2021] [Indexed: 11/23/2022]
Abstract
The study concerns mechanical behaviour of a living human abdominal wall. A better mechanical understanding of a human abdominal wall and recognition of its material properties is required to find mechanically compatible surgical meshes to significantly improve the treatment of ventral hernias. A non-invasive methodology, based on in vivo optical measurements is proposed to determine strains of abdominal wall corresponding to a known intraabdominal pressure. The measurement is performed in the course of a standard procedure of peritoneal dialysis. A dedicated experimental stand is designed for the experiment. The photogrammetric technique is employed to recover the three-dimensional surface geometry of the anterior abdominal wall at the initial and terminal instants of the dialysis. This corresponds to two deformation states, before and after filling the abdominal cavity with dialysis fluid. The study provides information on strain fields of living human abdominal wall. The inquiry is aimed at principal strains and their directions, observed at the level from -10% to 17%. The intraabdominal pressure related to the amount of introduced dialysis fluid measured within the medical procedure covers the range 11-18.5 cmH2O. The methodology leads to the deformation state of the abdominal wall according to the corresponding loading conditions. Therefore, the study is a step towards an identification of mechanical properties of living human abdominal wall.
Collapse
|
8
|
Application of Acellular Tissue Matrix for Enhancement of Weak Abdominal Wall in Animal Model. BIOMED RESEARCH INTERNATIONAL 2020; 2020:3475289. [PMID: 32258114 PMCID: PMC7091519 DOI: 10.1155/2020/3475289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 01/19/2020] [Accepted: 01/22/2020] [Indexed: 12/16/2022]
Abstract
Background Abdominal wall weakness occurs when the strength of muscle decreases due to physiological reason or iatrogenic injury. However, the treatment of this disease is complicated. Aim To study the therapeutic effect of acellular tissue matrix (ACTM), compared with the polypropylene mesh. Methods An abdominal wall weakness model was established in rabbits through motor nerves cutting. The polypropylene mesh and ACTM were implanted in the left and right abdomen sides, respectively. Mechanical testing of abdominal wall muscle and histology and scanning electron microscopy (SEM) evaluation of abdominal tissue explants were performed. Results In animal model establishment, the abdominal length of healthy and weakened abdominal wall was 17.0 ± 0.7 cm and 19.0 ± 1.2 cm, respectively (P=0.022), and the weak abdominal wall group showed a significant decrease of 1.116 ± 0.221 MPa in tensile stress (P=0.022), and the weak abdominal wall group showed a significant decrease of 1.116 ± 0.221 MPa in tensile stress (P=0.022), and the weak abdominal wall group showed a significant decrease of 1.116 ± 0.221 MPa in tensile stress (P=0.022), and the weak abdominal wall group showed a significant decrease of 1.116 ± 0.221 MPa in tensile stress (P=0.022), and the weak abdominal wall group showed a significant decrease of 1.116 ± 0.221 MPa in tensile stress (P=0.022), and the weak abdominal wall group showed a significant decrease of 1.116 ± 0.221 MPa in tensile stress (P=0.022), and the weak abdominal wall group showed a significant decrease of 1.116 ± 0.221 MPa in tensile stress ( Conclusion The abdominal wall weakness model in rabbits was successfully established. ACTM is a promising biological material to be possibly further applied in clinical surgery in patients with abdominal wall weakness.
Collapse
|