Impact of a prophylactic mesh on the biomechanics of abdominal wall closure: an animal study

The use of a prophylactic prosthetic mesh (PPM) to reinforce a midline laparotomy suture closure improves the clinical outcomes, in comparison with primary suture technique. However, understanding how a PPM impacts the biomechanics of the repair is crucial for gaining a deeper comprehension and ultimately improving clinical outcome by decreasing incisional hernia (IH) rates post midline laparotomy. Based on a porcine IH model, this study aimed to assess the biomechanical characteristics of the abdominal wall (AW) midline over time post midline laparotomy, considering sthree repair modalities: no repair, primary suture and onlay mesh reinforcement coupled with suture.

31 pigs were enrolled in the study and the repair was characterized using CT-scans based on the distance between the right and left Rectus Abdominis Muscle (RAM). The AW of each animal was explanted at 48 h, 4 and 12 weeks postoperatively and a Stereo Digital Image Correlation (s-DIC)-based method was used to assess the response of the repaired AW (e.g., strain, compliance) when subjected to an inflation test mimicking an increase in intra-abdominal pressure (IAP). Intact AW were included in the study and served as controls.

AWs repaired with a primary suture exhibited a higher RAM distance compared to healthy animals, along with an increased compliance of the repair along the transverse direction over time. AWs repaired with primary suture and reinforced with a PPM exhibited a biomechanical response similar to that of healthy animals in terms of repair strain and compliance.

The use of a PPM to reinforce suture was found to better restore the biomechanical properties to the midline of the AW post midline incision. Further investigations are needed to correlate the findings of this study with clinical outcomes, especially long-term recurrence rates.