Page 215 - Prevention and Treatment of Incisional Hernia- New Techniques and Materials

Measurements
Adhesion formation
After 30 days (group A) and 90 days (group B), the animals were anesthetized and the ventral abdominal wall was opened through a U-shaped incision (including skin) around the mesh. Pictures of the mesh and current adhesions were taken using a 5.0-megapixel digital camera (Sony Cybershot, Tokyo, Japan). Subsequently, the animals were killed by cardiac incision, adhesions were cut, and the abdominal wall including the mesh was removed. Two independent observers assessed the adhesion coverage of the mesh surface using a scoring system. A grid was placed over the mesh, dividing it into 24 equal squares and facilitating accurate estimation of adhesion formation. In case of interobserver variance, the mean was scored. For objective scoring of the severity of the adhesions, the Zühlke scoring system was used. This system has a four-degree classi cation of adhesions based on histologic and morphologic criteria (Table 2). Adhesions merely attached to the mesh edge did not contribute to the total adhesion score. Finally, the animals were killed by cardiac incision.
Table 2. Zühlke score: macroscopic classi cation of abdominal adhesions.
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Biological mesh in hernia repair
Zühlke score 1
2
3 4
Characteristics
Filmy adhesion, easy to separate by blunt dissection
Stronger adhesion; blunt dissection possible, partly sharp dissection necessary; beginning of vascularization
Stronger adhesion; lysis possible by sharp dissection only; clear vascularization
Very strong adhesion; lysis possible by sharp dissection only; organs strongly attached with severe adhesions; damage of organs hardly preventable
Incorporation
Mesh incorporation was de ned as the amount of the mesh edge (in millimeters) incorporated into the abdominal wall as a percentage of the circumference. In case of interobserver variance, the mean was scored.
Mesh shrinkage
Mesh shrinkage was de ned as the projection of the mesh surface and measured with a caliper by two independent observers. By measuring the projection, curling and wrinkling of the mesh were included in addition to the actual size of the mesh. Shrinkage was de ned as the relative loss of surface (%) compared with the original size of the mesh.
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