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Lesch et al. Mini-invasive Surg 2023;7:25 https://dx.doi.org/10.20517/2574-1225.2023.31 Page 9 of 13

Figure 7. Number of failures in 140 experiments grouped by the time of their occurrence, accumulating to 72 failures in total. The
occurrence of failure is divided into four groups of 100 DIS impacts each, comprising the observed failures. ES 7 and ES 14 are missing
since no failure was observed in these experiments.

tensile strength of the reconstruction materials is greater than that of the tissues. This is a requirement for
market certification. Thus, destructive examination of the reconstruction materials after market approval is
not decisive. The examination for fatigue of the entire compound under cyclic loading is necessary .
[22]

ASTM E606 is a standard test method working with uniaxial forces. It measures the fatigue properties of
homogenous materials due to strain . ASTM E606 needs to be expanded for organic polymers. Tissues
[23]
[24]
repaired with textile meshes require testing for destructive and healing processes . There are little data for
biological systems. Debonding and ligament fracture are also likely to occur in a biological matri × as
well . Non-crosslinked collagen elongates to weak fiber sheets without adequate retention force .
[26]
[25]
Overstrained repairs will not heal. A dehiscence occurs early, and incisional hernias develop as a
consequence .
[27]
Our bench test enables low cyclic fatigue (LCF) testing. Testing of abdominal wall closures ideally needs to
be performed repetitively almost 500 times. This ensures a realistic assessment of durability in the patient
under everyday conditions [Figure 3]. Considering other test designs (e.g., the AbdoMan ), our test bench
[28]
is the only one that allows this necessary repetitive assessment. The biomechanical influences acting on an
abdominal wall repair determine its outcome. The higher the applied peak pressure, the more energy is
transmitted to the mesh-tissue compound. More failures occur [cf. Figure 4]. For clinical practice, it is
relevant to keep intraabdominal pressure low after surgery. This can be achieved by avoiding stress or by
supporting the abdominal wall in stress distribution.

Our results show that an increase in intraabdominal pressure and variations in the biomechanical
circumstances have a clear impact on the outcome of the reconstruction. Therefore, in clinical practice, two
intervention options emerge for the stabilization of the abdominal wall reconstruction. One option is to
minimize the load through measures such as a resting period. Also, optimal coordination with the
[29]
anaesthesiologist regarding extubation and postoperative cough relief are viable options . Alternatively, a
reconstruction of the abdominal wall that reliably withstands the biomechanical stresses can be considered.
The GRIP/CRIP concept with CTAV allows a biomechanically calculated repair that remains stable after
three years of follow-up, with recurrence rates under 1 % .
[30]