Aim: Hernia repair strengthens the abdominal wall with a textile mesh. Recurrence and pain indicate weak bonds between mesh and tissue. It remains a question which biomechanical factors strengthen the mesh-tissue interface, and whether surgeons can enhance the bond between mesh and tissue.Material and Methods: This study assessed the strength of the mesh-tissue interface by dynamic loads. A self-built bench test delivered dynamic impacts. The test simulated coughing. Porcine and bovine tissue were used for the bench test. Tissue quality, mesh adhesiveness, and fixation intensity influenced the retention power. The influences were condensed in a formula to assess the durability of the repair. The formula was applied to clinical work. The relative strength of reconstruction was related to the individual human abdominal wall. From computerized tomography at rest and during Valsalva's Maneuver, the tissue quality of the individual patient was determined before surgery.Results: The results showed that biomechanical parameters observed in porcine, bovine, and human tissue were in the same range. Tissues failed in distinct patterns. Sutures slackened or burst at vulnerable points. Both the load duration and the peak load increased destruction. Stress concentrations elevated failure rates. Regional areas of force contortions increased stress concentrations. Hernia repair improved strain levels. Measures for improvement included the closure of the defect, use of higher dynamic intermittent strain (DIS) class meshes, increased mesh overlap, and additional fixation. Surgeons chose the safety margin of the reconstruction as desired.Conclusion: The tissue quality has now been introduced into the concept of a critical and a gained resistance toward pressure-related impacts. A durable hernia repair could be designed from available coefficients. Using biomechanical principles, surgeons could minimize pain levels. Mesh-related complications such as hernia recurrence can potentially be avoided in incisional hernia repair.

Purpose Incisional hernias often follow open abdominal surgery. A small-stitch–small-bite suture might close the incision durably. We analyzed specific details of this closure technique and assessed their influence on the closure stability. Methods The effects of cyclic loads, simulating coughs were investigated on a bench test. We prepared porcine bellies in the median line and bovine flanks parallel to the muscle fibers with 15 cm long incisions. Then we punched round or rhomboid defects with a diameter of 5–10 cm into the center of the incision. Monomax® 2–0 and Maxon® 1 and 2–0 were used as suture materials. We tested the durability of the closure with pressure impacts of 210 mmHg repeated 425 times. Throughout the experiments, we modified the suturing technique, the surgeon, the tissue tension, the defect size and shape and the suture diameter. Results Standardizing the suture technique improved the durability of the closure significantly. Any other variations showed minor influences after standardization. All incisions with round defects up to 7.5 cm width withstood 425 impacts using standardized suturing. Unstandardized sutures failed in all cases. When closing an incision with a 10 cm wide defect, the tissues ruptured frequently next to the suture line. We defined criteria to standardize this suturing technique. For the first time, we developed a suture factor related to the durability of a sutured tissue closure. We integrated the suture factor into the concept of biomechanically durable repairs. Conclusions Suturing the abdominal wall with a standardized suturing technique improves its durability significantly.

Aim “Can a mesh reduce failure rates after closure of a hernia defect?” Material and Methods “Porcine abdominal walls and bovine flanks were used as model tissues. After preparation, a 15 cm long incision was placed in the linea alba of the porcine abdominal wall. An additional round 5 cm defect was punched in the middle of the incision. The bovine flank was prepared in a similar manner. The incisions with the defects were closed with running sutures in a small stitch, small bite technique. Monomax® 2-0 sutures were used with suture to wound lengths above 4:1. Dynamesh® CiCAT meshes of three different sizes were placed in the sublay position. The mesh-tissue compounds were investigated on our self-built hydraulic bench test simulating coughs. Dynamic intermitted strain (DIS) was repeatedly delivered with impacts around 210 mmHg. Each of ten preparation was loaded 425 times by the pressure peaks.” Results “Small stitch, small bite sutures using 2-0 Monomax® with a suture-incision-ratio of 4.5:1 can provide a durable defect closure. Under other conditions, suture lines can reopen. A mesh reduces the recurrence of incisional hernia depending on the mesh size.” Conclusions “An additional DIS-class A mesh in sublay position can provide sufficient support for a suture closing the defect of the abdominal wall. It can prevent a tear-out of the suture from the tissue. On average, a mesh-augmented defect closure reduces the recurrence rate of incisional hernia.”