Page 103 - Postoperative Intra-Abdominal Adhesions- New insights in prevention and consequences

Biological and synthetic meshes in ventral hernia repair
using isoflurane/O2 inhalation and buprenorphin analgesia (0,05 mg/kg) administered subcutaneously. The abdomen was shaved and cleaned with alcohol 70%, after which a 5-cm midline skin incision was made and skin flaps were raised. Subsequently, the abdominal cavity was opened with a 4-cm midline incision through the linea alba. A sterile mesh, measuring 2,5 x 3,5 cm, was placed in an intraperitoneally position and fixated transmusculary with six non-absorbable sutures. The abdominal wall and skin were both closed with a running absorbable suture.
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 6 and current adhesions were taken (5.0 megapixels digital camera, Sony Cybershot). 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 classification of adhesions based on histological and morphological criteria (Table 2). Adhesions merely attached to the mesh edge did not contribute to the total adhesion score. Finally the animals were terminated by cardiac incision.
Table 2. Zühlke score: macroscopic classification of abdominal adhesions.
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
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