PERITONEAL ADHESIONS TYPE I, III AND TOTAL COLLAGEN ON POLYPROPYLENE AND COATED POLYPROPYLENE MESHES: EXPERIMENTAL STUDY IN RATS

IS THERE NEURAL AND FUNCTIONAL RECOVERY AFTER CLIP REMOVAL IN CERVICAL EXPERIMENTAL SYMPATHECTOMY?

Background:

The surgical treatment of hyperhidrosis by thoracic sympathectomy has brought, in addition to symptomatic relief for many, its main adverse effect: compensatory or reflex sweating. The clipping technique in place of the sympathetic nerve section gave rise to the hope of reversibility, but the positive results showed to be quite divergent, evidencing the academic deficiency regarding the study of this phenomenon.

Aim:

To observe micro and macroscopic damage caused by the polymer clip on sympathetic nerve of rabbits seven days after their clipping and the findings after three weeks of clip removal.

Method:

In this experimental study, 20 rabbits were divided into two groups of 10, group 1 (clipping) and group 2 (de-clipping). The right cervical sympathetic nerve of all animals was clamped with polymeric clip, and in group 2 the nerve was unclipped seven days later. Group 1 rabbits were induced to death on the 7th postoperative day, and group 2 on the 21st after removal of the polymer clip. Macroscopic variables were: clip appearance, presence of discontinuity lesion, infection and adhesions around the nerve. H&E was used in the evaluation of the phases and degree of the inflammatory process and presence of necrosis, and picrosirius red F3BA for quantification of collagen.

Results:

The cervical sympathetic nerve was intact, without necrosis or infection in all animals of the experiment; there were adhesions in both groups, being minimal in eight animals of each group and moderate or intense in two; the clip was completely closed in all animals at the 7th postoperative day; the inflammatory process shown was chronic, with monomorphonuclear predominance. There was no significant difference between groups regarding the intensity the inflammatory process, but the amount of collagen type I and type III was significantly higher in group 2.

Conclusions:

The injury caused by the polymer clip on the sympathetic nerve may be reversible, allowing functional return in the areas involved in the simulated cervical sympathectomy. Clipping of the cervical sympathetic nerve using a polymer clip does not cause discontinuity injury.

Biomaterial Implants in Abdominal Wall Hernia Repair: A Review on the Importance of the Peritoneal Interface

Biomaterials have long been used to repair defects in the clinical setting, which has led to the development of a wide variety of new materials tailored to specific therapeutic purposes. The efficiency in the repair of the defect and the safety of the different materials employed are determined not only by the nature and structure of their components, but also by the anatomical site where they will be located. Biomaterial implantation into the abdominal cavity in the form of a surgical mesh, such as in the case of abdominal hernia repair, involves the contact between the foreign material and the peritoneum. This review summarizes the different biomaterials currently available in hernia mesh repair and provides insights into a series of peculiarities that must be addressed when designing the optimal mesh to be used in this interface.