Page 114 - Postoperative Intra-Abdominal Adhesions- New insights in prevention and consequences

Chapter 6
In our study a wide variation in adhesion formation to the mesh was seen in the Strattice group at 30 days. In two cases less than 5% of the surface was covered with adhesions, whereas in two other cases organs were attached to the Strattice mesh. Remarkably the amount of adhesions attached to the mesh dropped dramatically from 40% at 30 days to 5% at 90 days. In combination with a significant lower tenacity of adhesions compared to the Prolene mesh at 90 days, this may suggest less severe adhesion formation to Strattice mesh on the long term. This may be explained by the histologic result similar to that of Parietex composite meshes, showing a new mesothelial layer at the visceral side of the mesh. Our result of a wide variation at 30 days is consistent with Mulier et al, who also found a wide distribution in adhesion formation. However, they did not mention whether any organs were involved or not [35]. At 90 days 40% of the Strattice mesh edge was incorporated in the abdominal wall. In contrast to the results at 30 days correlation between adhesions and incorporation could not be found anymore because very few adhesions were seen. Histological examination with picrosirius red staining showed almost no degradation of the mesh. Additionally a small and sharply bordered layer of novel connective tissue was seen between mesh and abdominal wall, confirming the macroscopic observation of limited incorporation.
The amount of adhesions to Permacol mesh after 90 days (74.8 %) was significantly diminished compared with the amount after 30 days (87.5 %), whereas the Zu ḧ lke score was not. This may be explained by the reduction in filmy adhesions, whereas, in contrast, bowel or liver adhered to 57 % of the meshes. In the literature, these extensive adhesions and limited adhesion formation to Permacol mesh are described [36, 37]. Mesh edge incorporation at 90 days was 21 %, and in contrast to Strattice and Surgisis, no correlation between adhesion formation and incorporation was found at either time point. Histologic examination after 30 days showed a substantial fibrotic layer between the Permacol mesh and the abdominal wall, and picrosirius red staining did not show a transition layer with degradation of the mesh or new collagen formation. Additionally, the macroscopic observation of liver adhered to the mesh was microscopically confirmed with a fibrotic reaction between liver and mesh (Fig. 5).
112