Study of the biomechanical response of a prosthetic mesh secured with penetrating and non-penetrating fixations in IPOM ventral hernia repair.

INTRODUCTION: Sutures or tacks are commonly used to secure a mesh in intraperitoneal onlay mesh (IPOM) hernia repair, but such penetrating fixations can cause local damage, that can be associated with pain. The use of an adhesive could be an alternative to reduce complications. However, a risk associated with this approach has been identified, particularly when the defect cannot be closed. A mesh glued to the peritoneum only might not provide as much mechanical reinforcement to the abdominal wall (AW) as a mesh anchored to the myofascial structure with penetrating fixations, which could lead to an increased recurrence rate. Additionally, the high elasticity of the peritoneum may increase mesh bulging. Leveraging an ex vivo approach, the objective of this study was to investigate the impact of mesh fixation using glue versus barbed sutures, on its biomechanical response for IPOM surgery. METHODS: An experimental method was developed using ex vivo porcine abdominal wall samples (n = 12). A 4-cm centered circular defect was created by dissecting the skin and the subcutaneous tissue and removing muscle and extraperitoneal fat, while keeping the peritoneum intact. A 14-cm diameter mesh was secured (Dermabond™ cyanoacrylate adhesive or V-Loc™ barbed sutures) to the AW. The mesh was placed on the peritoneum to remain consistent with the IPOM placement. The sample was then subjected to some inflation tests to simulate increased levels of intra-abdominal pressure (IAP) representing daily activities. For each test, mesh bulging into the defect was assessed as a function of the pressure using Digital Image Correlation (DIC) analysis. RESULTS: Mesh bulging was studied for 2 configurations: suture fixation and glue. Glued meshes exhibited significantly higher bulging values than when sutured with a significant difference (p = 0.013) observed at 252 mmHg and a certain trend for statistical difference (p < 0.1) for stair climbing or coughing activities. Additionally, the stiffness of the repair was also significantly higher when the mesh was sutured compared to when it was glued to the peritoneum (p < 0.05). CONCLUSION: This study demonstrated that a mesh glued to the peritoneum exhibited higher bulging and a behavior of the repair less stiff compared to when it was sutured to the myofascial structure of the AW, particularly for high intra-abdominal pressures. However, the impact of these differences remains to be evaluated over time. Further preclinical investigations are needed to quantify their impact post-operatively.

Differences in biomechanics of abdominal wall closure with and without mesh reinforcement: A study in post mortem human specimens.

INTRODUCTION: Small bites for the closure of the abdominal wall after midline laparotomy result in significantly less incisional hernias in comparison with large bites. However, fundamental knowledge of underlying biomechanical phenomena remains sparse. The objective of this study was to develop a digital image correlation-based method to compare different suturing techniques in terms of strain pattern after closure of a midline laparotomy in a passive model just after the time of surgery. METHODS: A digital image correlation (DIC)-based method was used for the comparison of strain fields on the external surface of the myofascial abdominal wall (skin and subcutaneous fat removed) among six configurations, including an intact linea alba in five post mortem human specimens. The second configuration comprised primary mass closure with small bites (five mm between two consecutive stitches and five mm distance from the incision, 5x5 mm). The third configuration was primary mass closure with large bites (ten mm by ten mm, 10x10 mm). The fourth, fifth and sixth configuration comprised primary mass closure with large bites and the placement of a mesh in onlay position with two different overlaps and the use of glue to simulate the integration of the mesh within the soft tissue. RESULTS: No visible difference was observed between 5x5 and 10x10 mm closure configurations. However, the use of mesh as suture line reinforcement highlighted a stiffer behavior of the midline area for similar intra-abdominal pressure, which was amplified when a larger mesh overlap was used. However, the whole abdominal wall showed quite similar shapes for the various configurations, except for the configuration with mesh reinforcement and the use of glue. CONCLUSION: Mesh reinforcement incited lower opening tension profiles in the midline area of the abdominal wall. following closure of the linea alba in median laparotomy. The next step should be to investigate the impact of mesh location (e.g. retromuscular) and different time points after surgery.