ESTUDO COMPARATIVO DO EFEITO DAS TELAS DE POLITETRAFLUOROETILENO EXPANDIDO E DE POLIPROPILENO, COLOCADAS POR LAPAROSCOPIA, EM HÉRNIAS VENTRAIS PRODUZIDAS EM COELHOS

BETWEEN PROLENE®, ULTRAPRO® AND BARD SOFT® MESHES WHICH PRESENTS THE BEST PERFORMANCE IN THE REPAIR OF THE ABDOMINAL WALL?

BACKGROUND

In the definition of the mesh to be used to correct hernias, porosity, amount of absorbable material and polypropylene should be considered in the different stages of healing process.

AIM

To evaluate the inflammatory reaction in the use of macro and microporous meshes of high and low weight in the repair of defects in the abdominal wall of rats.

METHODS

Ninety Wistar rats (Rattus norvegicus albinus) were used. The animals were submitted to similar surgical procedures, with lesion of the ventral abdominal wall, maintaining the integrity of the parietal peritoneum and correction using the studied meshes (Prolene®, Ultrapro® and Bard Soft®). Euthanasia was performed at 30, 60 and 120 days after surgery. The abdominal wall segments were submitted to histological analysis using H&E, Masson's trichrome, immunohistochemistry, picrosirius red and tensiometric evaluation.

RESULTS

On the 120th day, the tensiometric analysis was superior with Ultrapro® macroporous mesh. The inflammatory process score showed a significant prevalence of subacute process at the beginning and at the end of the study. Microporous meshes showed block encapsulation and in macroporous predominance of filamentous encapsulation.

CONCLUSION

The Ultrapro® mesh showed better performance than the others in healing process of the abdominal wall.

Comparative study between polypropylene and polypropylene/poliglecaprone meshes used in the correction of abdominal wall defect in rats

PURPOSE

To evaluate the healing process of a defect in the ventral abdominal wall of rats, comparing the polypropylene and polypropylene/poliglecaprone meshes on the 30(th) and 60(th) postoperative day.

METHODS

Thirty two Wistar rats were submitted to a ventral abdominal wall defect, with integrity of the parietal peritoneum. In the repair, were used polypropylene (group A) and polypropylene/poliglecaprone (group B) meshes. The groups were subdivided into four subgroups of eight animals euthanized on the 30(th) (A30 and B30) and 60(th) postoperative day (A60 and B60). Fragments of the abdominal wall of the animals were submitted to macroscopic, tensiometric and histological evaluations.

RESULTS

The tensiometry on subgroup A30 showed a mean average break point of 0.78 MPa and in A60, 0.66 Mpa. In subgroup B30 it was 0.84 MPa and in B60, 1.27 Mpa. The score of the inflammatory process showed subacute phase on A30 and B30 sub-groups and chronic inflammatory process in subgroups A30 and 60B.

CONCLUSIONS

The tensile strength was higher on the wall repaired by polypropylene/poliglecaprone mesh in the 60(th) post-operative day. Histology showed higher concentration of fibrosis on the surface of the polypropylene mesh with a tendency to encapsulation. In polypropylene/poliglecaprone subgroups the histology showed higher concentration of fibrosis on the surface of mesh filaments.

May titanium spiral tacks contribute to intra-abdominal adhesion formation?

PURPOSE

To verify if titanium spiral tacks may contribute to intra-abdominal adhesion formation in rabbits.

METHODS

Ten New Zealand white rabbits were used. Through videolaparoscopic surgery two titanium spiral tacks (ProTack(®), Covidien(®)) were applied in the right flank. After 30 days the animals were submitted to evaluate peritoneal cavity by videolaparoscopy.

RESULTS

No adhesion was found where the titanium spiral tacks were placed.

CONCLUSION

Titanium spiral tacks for fixation do not cause adhesions in rabbits.

O uso de telas Parietex® e Surgisis® na correção de defeitos produzidos na parede abdominal de coelhos

RACIONAL: Na cirurgia geral, as correções das hérnias da parede abdominal ocupam lugar de destaque e, cada vez mais, as indicações e usos de telas têm aumentado devido aos melhores resultados. OBJETIVO: Comparar as correções de orifícios produzidos em parede abdominal com telas Parietex® e Surgisis® em contato direto com as vísceras abdominais. MÉTODO: Para os experimentos foram utilizadas 16 coelhas adultas jovens e produção de defeitos triangulares de 2 cm de base por 2,5 cm de altura, comprometendo os planos músculo-aponeurótico-peritoniais da parede abdominal, nos flancos, simétricos à linha média que foram corrigidos com telas retangulares de 3 cm de base por 3,5 cm de altura. No lado direito usou-se tela Parietex® (poliéster/colágeno-polietilenoglicol-glicerol) e no lado esquerdo tela Surgisis® (submucosa intestinal suína). Na avaliação utilizaram-se parâmetros clínico-cirúrgicos, histológicos e imunoistoquímicos. Oito coelhas foram submetidas a eutanásia em 30 dias e as 8 restantes, em 60. Comparou-se a eficiência das duas telas. RESULTADOS: As duas telas provocaram erosões de pele e não ocorreu nenhum caso de hérnia incisional. As aderências ocorreram em todas as telas no primeiro mês e em menor grau e intensidade, no segundo mês; a retração delas foi de 1/3 do tamanho original; a Parietex® provocou menor processo inflamatório; não houve diferença significante de deposição de entre as duas telas; a deposição do colágeno tipo III foi mais intensa no segundo mês em ambas; na remodelação do colágeno a produção da enzima MMP8 foi maior na tela Parietex® no primeiro mês e a enzima MMP13 aumentou no segundo mês em ambas as telas, porém com significância apenas na Parietex®. CONCLUSÃO: As duas telas foram eficientes na correção de hérnias incisionais e com resultados semelhantes, sendo que a Parietex® apresentou menor processo inflamatório, maior quantidade de metaloproteinases MMP8 e MMP13 em relação à Surgisis®.

Infection on the meshes implantation area in the abdominal wall of rats with induced bacterial peritonitis

PURPOSE: Evaluate incidence of bacterial growth on implanted meshes in the abdominal wall of rats after to induce bacterial peritonitis. METHODS: 36 rats were used. They were allocated in two groups: group B, experiment group (n =18) and group S, control group (n =18). They were submitted to the implant of polypropylene meshes on the abdominal wall, at the preperitoneal space. Then, in the animals of the experiment group, the induction of peritonitis was made through the inoculation in the peritoneal cavity of standardized solution of Escherichia coli. In the animals of the control group it was made through the inoculation of physiologic solution. The animals of both groups were reallocated in three subgroups of six animals and observed until the reoperations time, for evaluation of the implantation sites, collection of the meshes for cultures, evaluation of the abdominal cavity and peritoneal lavage for cultures. The reoperations occurred in 24, 48 and 72 hours. RESULTS: All the animals of the experiment group presented clinical symptoms of peritonitis. The cultures of the meshes taken off from the implantation sites were positive in 83% of the animals when the moment of the evaluations was of 24 hours, decreasing to 33% in 48 hours and 17% in 72 hours. Globally, it was of 44%. In the animals of the control group there was no case of positive culture neither in the meshes, nor in the peritoneal lavages. CONCLUSIONS: The experimental model used was effective, producing 100% of peritonitis. The incidence of bacterial growth on the implanted polypropylene meshes was 83% in 24 hours, decreasing with the time.