Cyclic pulse loads pave the road to the GRIP concept in abdominal wall reconstruction

Aim: : Durable reconstruction of the abdominal wall needs to be assessed in a lifelike experimental setting and consider the reconstructed abdominal wall as a coherent compound. Our aim was to evaluate broader possibilities in preclinical testing and to deepen the understanding of the biomechanical influences. Methods: : We developed a test bench that allows studying a compound under cyclic, repetitive loads. Pulse loads transmit energy to the abdominal wall repeatedly. The amount of energy is related to the load characteristics. We used porcine bellies with a round central (5 cm) defect. They were bridged in a sublay position with Cicat Dynamesh (R). (R) . Further defects, located in an additional incision, were sutured in a standardized small-bite technique. We varied the number of loads, the maximum peak pressure, the pressure plateau length, and the impact area size. Results: : Increasing the peak pressure by 30 mmHg lowers the durability by about 20 %. Prolonging the plateau phase led to a significant durability decrease. During the first 100 dynamic intermittent strain (DIS) impacts, the major tissue deformation and the majority of failures occur. Beyond the 425th DIS impact, about 10 % more failures occur. Increasing elongation and deformation of the tissue raise the likelihood of failure. Conclusion: : If the compound does not establish a strain-stable condition during the period of plastic deformation, failure occurs. The outcome does not only depend on the reconstruction technique but also on the external influences acting on the abdominal wall compound. Considering the biomechanical reality is important for open and minimally invasive abdominal wall reconstruction.