Page 244 - Prevention and Treatment of Incisional Hernia- New Techniques and Materials

Chapter 11
Intra-abdominal adhesion and abscess formation are important causes of morbidity and mortality following contaminated abdominal surgery. During peritonitis brin is deposited in the abdominal cavity, inducing adhesion formation and providing possible niduses for abscess formation(9). Biological Strattice® mesh showed low adhesion formation after 90 days, con rming previous experimental results(26-28). Sepramesh® showed a signi cant increase in adhesion formation between 28 and 90 days, implying that the cellulose–hyaluronate coating is absorbed before a neoperitoneal layer is formed. These results con rm that adhesion formation in the presence of mesh is not complete after 7 days(8, 11). The surface of Parietene Composite® and Omyramesh® were least covered with adhesions after 90 days. Low adhesion formation on the collagen-coated Parietene Composite® has been described in a clean environment(8, 11). The present results suggest that the collagen coating remains present until a neoperitoneum has formed, even in a contaminated environment. The low adhesion formation on Omyramesh® con rms experimental ndings with this relatively new mesh in a clean environment(29, 30). The low adhesion formation might be explained by its smooth, monolayer, non- brous, macroporous structure. The plain polypropylene Parietene® mesh was largely covered with adhesions. Clinically, uncoated polypropylene meshes are known to induce severe adhesion formation with attachment of intestine to the mesh when implanted intraperitoneally(7, 31). In 21 % of patients with an intraperitoneal uncoated polypropylene mesh, adhesions made bowel resection necessary during re-exploration in one study(7).
The non-infected, partially microporous, expanded PTFE Dualmesh® had an alarmingly high shrinkage rate (median 63 % after 90 days). Such shrinkage has frequently been reported experimentally, but this does not seem to be correlated with a higher recurrence rate clinically(8, 23, 32). A brous capsule surrounding the mesh was observed, almost without cellular in ltration into the mesh. Contraction of this capsule was probably the cause of shrinkage, which might have been more pronounced in the small meshes used in the present experiment compared with the much larger meshes used clinically. Of the macroporous meshes, the plain polypropylene Parietene® showed the most shrinkage (15 % after 90 days), con rming experimental results(32, 33).
The biological Strattice® mesh had a 23 % loss of surface after 90 days, probably caused by collagenase activity. Premature weakening of the biomechanical properties of the sca old combined with insu cient
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