Membrana de celulose microbiana e de politetrafluoretileno expandido usadas como implante na reconstrução de defeito músculo - aponeurótico agudo produzido na parede abdominal de ratos. Estudo comparativo.

Abstract

Reconstruction of muscle-apneurotic defects can be affected by the distance among the edges or by the lack of tissue with characteristics for appropriate surgical synthesis. In these cases, muscles grafts and synthetic or biological implants can be used. Objective; To evaluate the use of microbial cellulose (Zoogloea sp.) in defects produced in the abdominal wall of rats. Materials and Methods; Sixty male Wistar rats, with mean weight of 437,7±40,9g, anesthetized with a mixture of ketamine and xylazine, were submitted to a rectangular excision (2x3cm) including fascia, muscles and peritoneum, as well as treated with implants of membranes of microbial cellulose (CM) ( CM Group - 30 animals) or expanded polytetrafluoroethylene (ePTFE) (ePTFE Group - 30 animals). Such groups were subdivided in Subgroups 14th POD, 28th POD and 60th POD, in agreement with the evaluation period. In these periods the animals were submitted to the euthanasia for evaluation biomechanics and histological observations. Results; The levels of Load of Rupture were progressive and significantly high among Subgroups 14th POD, 28th POD and 60th POD of each studied Group. The values of the Load of Rupture were significantly larger in the ePTFE Group than in the CM Group. In the ePTFE Group there was ingrowth of host tissue into implants in 100% of the analyzed samples. In the MC Group such ingrowth was not observed in 100% of the examined specimens. Discussion; The elevated levels of Load of Rupture in the implant/host interface in the ePTFE Group are indicative of the presence of infiltration of host tissue in the porous structure of this material, aspect not observed in the microporous architecture of CM membrane. Conclusions; In agreement with the biomechanics evaluation, the implant/host interface showed to be more resistant with ePTFE than with CM. The histological changes evidenced infiltration of host tissue in the implants accomplished with ePTFE.