Different cellular and immunohistochemical abdominal wall cicatrization parameters evaluation in comparison with sublay, onlay, and ipom technique in an experimental rat model

PURPOSE

Incisional hernia (IH) occurs when there is a partial or complete solution of continuity of a fascia previously incised. Systematic reviews demonstrate that surgical treatment of IHs with the use of meshes are approximately 16%. Meta-analyses have demonstrated the superiority of mesh placement using sublay technique, but without a pathophysiological explanation. Thus, we aim to evaluate the different techniques of mesh positioning in an experimental model.

METHODS

Fifty rats were distributed into five groups; control; simulation (SM)-submitted to laparotomy only; onlay-the mesh was positioned in onlay fashion; retromuscular (SL)-the mesh was positioned in a sublay fashion; intraperitoneal (IPOM)-positioning of the mesh adjacent to the transversalis fascia, inside the cavity. After 60 days, adhesions, tensiometry, histology, and immunohistochemistry were addressed.

RESULTS

The IPOM group had the most adhesions, together with the SL group, with significantly relevant results. The SL group had higher values of tensiometric evaluation, while the IPOM group had the lowest mean in the tensiometry evaluation, being even lower than the SM group. Regarding histological and immunohistochemical findings, the SL group had a higher pixel number count compared to the groups, with statistical significance, in addition to higher expression of polymorphonuclear infiltrate and CD68 markers.

CONCLUSION

The mesh positioning in sublay compartment is associated with the development of more pronounce minimum tensile force required for detaching the surrounding abdominal wall tissues it was incorporated. The intensity of these findings correlates to the different histological and immunohistochemical profiles observed following each repair, since SL group was characterized by a higher proportion of collagen, inflammatory, and reparative elements. Characterizing these pro-healing elements and its counterparts will allow the development of new therapeutic tools which could be added to the still far-from-ideal current therapeutic options for IH treatment.

[The salivary glands of Philodryas patagoniensis Girard, 1857 (Serpentes, Colubridae). A morphological, morphometric and histological study]

Morphological, morphometrical and histochemical studies of the cell types in the salivary glands of Philodryas patagoniensis have been performed. It is concluded: 1) the acini of supra, infralabial and premaxillary glands are formed by mucous and mucoserous cells; the Duvernoy's gland by seromucous cells; 2) mucous cells show neutral and sulphated mucosubstances and sialic acid; mucoserous cells show neutral mucosubstance, sialic acid and protein radicals; seromucous cells of Duvernoy's gland show neutral mucosubstance and protein radicals. The acinar area, height of tubule and duct cells, and nuclear volume of acinar, tubule and duct cells were evaluated morphometrically.

Morphometric study of the effect of hypervitaminosis A on the sublingual gland of the rat

Hypervitaminosis A induces the following changes in the rat sublingual gland: smaller size acini with lower cells and smaller nuclei. The serous demilunes show smaller cells and nuclei. The striated ducts show smaller and disorganized cells with smaller nuclei. These data were confirmed by morphometric techniques.