A membrana de látex como implante para correção de defeitos musculares em cães e coelhos

Abstract

This dissertation presents an implant model of natural latex to be used on partial canine diaphragm replacement. The implant could be used in cases of diaphragmatic hernias, or significant loss of the diaphragm integrity disabling its reconstitution. For such, seven different membranes had been tested, six of them had been produced experimentally and one is a commercial model in use, for several applications. Firstly, the biocompatibility was evaluated in rabbits. Membranes were implanted between the cutaneous and the oblique abdominal sternum muscles by the means of a surgical procedure and the reactions of hipersensibility and rejection were evaluated. Mechanical traction tests were performed in control membranes to measure deformation and resistance. Results pointed that the membranes are incompatible, and not able to substitute muscular sheath in rabbits. New tests were made in dogs. The membranes were regrouped and three of then were tested in a similar way, in abdomen straight muscle. Two membranes were selected, for use in the canine diaphragm, and being tested in front a control group, without membrane. A rectangular defect (4 cm in length and 3 cm in width) was created in the diaphragm muscle, which was substituted, in groups 1 and 2, by the implantation of the corresponding latex membrane. The animals were evaluated radiographically, by blood count, video-surgery, and histopathology study. The results showed that the membrane made of natural latex, vulcanizants mixture and formic acid, were efficient in the correction of the diaphragm defect, promoting repair and local neovascularization, capable to keep the respiratory function and movements of the diaphragm without causing rejection during the evaluated period.