THE USE OF SURGICAL ADHESIVE AND SUTURE FIXING MESHES TO THE ABDOMINAL WALL: AN EXPERIMENTAL STUDY IN RATS.

AIM: Proper fixation of the surgical mesh determines the success of a herniorrhaphy. Understanding the inflammatory response and the mechanical properties of the mesh helps to define whether a fixation method is superior. This study aimed to evaluate the healing of defects in the abdominal wall of rats, comparing the repair of macroporous polypropylene meshes fixed with surgical glue and polypropylene thread. METHODS: In 20 Wistar rats, a defect was produced in the abdominal wall, with the integrity of the parietal peritoneum. For correction, the meshes were fixed with surgical glue (2-octyl cyanoacrylate) (subgroup C1), or polypropylene suture (subgroup C2). The two subgroups of 10 animals were euthanized on the 90th postoperative day, and the fragments of the abdominal wall were submitted to macroscopic, histological, and tensiometric analysis. RESULTS: Macroscopic analysis did not show any abnormalities. Tensiometry on the 90th postoperative day in subgroup C1 showed mean rupture tension of 28.47N and in subgroup C2 32.06N (p=0.773). The inflammatory process score revealed that both groups are in the subacute phase (p=0.380). CONCLUSION: The fixation of a polypropylene macroporous mesh to repair an abdominal wall defect can be performed with surgical glue (2-octyl cyanoacrylate) or polypropylene suture, both methods being equally effective.

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.

Histological evaluation of capsules formed by texturized silicone implants with and without polyester mesh coverage (Parietex®). A study on female rats.

PURPOSE: To evaluate capsules formed by microtextured silicone implants with and without Parietex® mesh coverage histologically. METHODS: Sixty Wistar rats were divided in two groups (meshed and unmeshed). Each group was, then, divided into two subgroups for evaluation at 30 and 90 days. Capsules were analyzed based on hematoxylin and eosin (HE) and picrosirius staining. RESULTS: The number of fibroblasts, neutrophils and macrophages was similar among all subgroups. There was a higher lymphocyte reaction in the 30-day meshed group (p = 0.003). Giant cell reaction, granulation tissue and neoangiogenesis were similar among the subgroups. Synovial metaplasia was milder at 90-day in the unmeshed (p = 0.002) and meshed group (p < 0.001). Capsular thickness was significantly greater in the meshed samples (30-day p < 0.001 and 90-day p < 0.001). There was a similar amount of collagen types I and III in both groups. CONCLUSIONS: The mesh-covered implants produced capsules similar to the microtextured ones when analyzing inflammatory variables. Synovial metaplasia was milder at 90 than at 30 days, and the capsular thickness was significantly greater in the meshed group. A similar amount of collagen types I and III was observed. Due to these characteristics, the mesh coverage did not seem to significantly affect the local inflammatory activity.

TENSIOMETRIC ANALYSIS OF MESHES USED IN ABDOMINAL VENTRAL WALL DEFECTS IN RATS.

BACKGROUND: Among the various strategies to avoid exaggerated foreign body reaction in the treatment of hernias is the limitation of the amount of polypropylene or the use of absorbable material. AIM: To evaluate the healing of defects in the abdominal wall of rats, comparing microporous polypropylene, macroporous polypropylene and polypropylene/polyglecaprone at the 30º, 60º and 120º postoperative day. METHODS: Wistar rats were submitted to defect production in the ventral abdominal wall, with integrity of the parietal peritoneum. Prolene®, Ultrapro® and Bard Soft® meshes were used in the correction of the defect. Nine subgroups of 10 animals were submitted to euthanasia at 30th, 60th and 120th postoperative day. Fragments of the abdominal wall of the animals were submitted to tensiometric analysis. RESULTS: The tensiometry at the 30th postoperative day showed greater resistance of the tissues with Bard Soft® (macroporous mesh) in relation to the tissues with Prolene® (microporous mesh). On the 60th postoperative day Bard Soft® maintained the superior resistance to the tissues comparing to Prolene Mesh®. On the 120th postoperative day the tissues repaired with Ultrapro® (macroporous mesh) proved to be more resistant than the ones by Prolene® (microporous mesh) and Bard Soft® (macroporous mesh). CONCLUSION: The tissues repaired with macroporous meshes showed greater resistance than with microporous meshes at all stages, and at 120 days postoperative Ultrapro® performed better than the others.

Between prolene®, ultrapro® and bard soft® meshes which presents the best performance in the repair of the abdominal wall? / Dentre as telas prolene®, ultrapro® ebard soft® qual apresenta melhor desempenho no reparo da parede abdominal?

ABSTRACT 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.

RESUMO Racional: Na definição da tela a ser utilizada na correção das hérnias deve-se considerar a porosidade, quantidade de material absorvível e polipropileno ou inabsorvível nas diversas fases da cicatrização. Objetivo: Avaliar a reação inflamatória das telas macro e microporosas de alta e baixa gramatura no reparo de defeito da parede abdominal de ratos. Método: Foram utilizados 90 ratos da raça Wistar (Rattus norvegicus albinus). Os animais foram submetidos a procedimentos cirúrgicos semelhantes, com lesão da parede abdominal ventral, mantendo a integridade do peritônio parietal e correção utilizando as telas Prolene®, Ultrapro® e Bard Soft®. Realizou-se a eutanásia aos 30, 60 e 120 dias de pós-operatório. Os segmentos da parede abdominal foram submetidos à análise histológica com H&E, tricômio de Masson, imunoistoquímica, picrosirius red e análise tensiométrica. Resultado: No 120º dia a análise tensiométrica mostrou superioridade da tela macroporosa Ultrapro®. O escore do processo inflamatório demonstrou prevalência significativa de processo subagudo no início e no final do estudo. As telas microporosas mostraram encapsulamento em bloco e as macroporosas encapsulamento predominantemente filamentar. Conclusão: A tela Ultrapro® mostrou melhor desempenho em relação às demais na cicatrização da parede abdominal.

Histological evaluation of capsules formed by texturized silicone implants with and without polyester mesh coverage (Parietex®). A study on female rats

ABSTRACT Purpose To evaluate capsules formed by microtextured silicone implants with and without Parietex® mesh coverage histologically. Methods Sixty Wistar rats were divided in two groups (meshed and unmeshed). Each group was, then, divided into two subgroups for evaluation at 30 and 90 days. Capsules were analyzed based on hematoxylin and eosin (HE) and picrosirius staining. Results The number of fibroblasts, neutrophils and macrophages was similar among all subgroups. There was a higher lymphocyte reaction in the 30-day meshed group (p = 0.003). Giant cell reaction, granulation tissue and neoangiogenesis were similar among the subgroups. Synovial metaplasia was milder at 90-day in the unmeshed (p = 0.002) and meshed group (p < 0.001). Capsular thickness was significantly greater in the meshed samples (30-day p < 0.001 and 90-day p < 0.001). There was a similar amount of collagen types I and III in both groups. Conclusions The mesh-covered implants produced capsules similar to the microtextured ones when analyzing inflammatory variables. Synovial metaplasia was milder at 90 than at 30 days, and the capsular thickness was significantly greater in the meshed group. A similar amount of collagen types I and III was observed. Due to these characteristics, the mesh coverage did not seem to significantly affect the local inflammatory activity.

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.

Tensiometric analysis of meshes used in abdominal ventral wall defects in rats / Estudo tensiométrico de telas utilizadas na correção de defeito na parede abdominal ventral de ratos

ABSTRACT Background: Among the various strategies to avoid exaggerated foreign body reaction in the treatment of hernias is the limitation of the amount of polypropylene or the use of absorbable material. Aim: To evaluate the healing of defects in the abdominal wall of rats, comparing microporous polypropylene, macroporous polypropylene and polypropylene/polyglecaprone at the 30º, 60º and 120º postoperative day. Methods: Wistar rats were submitted to defect production in the ventral abdominal wall, with integrity of the parietal peritoneum. Prolene®, Ultrapro® and Bard Soft® meshes were used in the correction of the defect. Nine subgroups of 10 animals were submitted to euthanasia at 30th, 60th and 120th postoperative day. Fragments of the abdominal wall of the animals were submitted to tensiometric analysis. Results: The tensiometry at the 30th postoperative day showed greater resistance of the tissues with Bard Soft® (macroporous mesh) in relation to the tissues with Prolene® (microporous mesh). On the 60th postoperative day Bard Soft® maintained the superior resistance to the tissues comparing to Prolene Mesh®. On the 120th postoperative day the tissues repaired with Ultrapro® (macroporous mesh) proved to be more resistant than the ones by Prolene® (microporous mesh) and Bard Soft® (macroporous mesh). Conclusion: The tissues repaired with macroporous meshes showed greater resistance than with microporous meshes at all stages, and at 120 days postoperative Ultrapro® performed better than the others.

RESUMO Racional: Dentre as várias estratégias para evitar exagerada reação de corpo estranho no tratamento das hérnias está a limitação da quantidade de polipropileno na tela ou utilização de material absorvível. Objetivo: Avaliar a cicatrização de defeito em parede abdominal de ratos, comparando-se as telas de polipropileno microporosa, polipropileno macroporosa e polipropileno/poliglecaprone. Métodos: Em 90 ratos Wistar foi produzido defeito na parede abdominal ventral, com integridade do peritônio parietal. Na correção foram utilizadas as telas Prolene®, Ultrapro® e Bard Soft®. Nove subgrupos de 10 animais foram submetidos à eutanásia no 30º, 60º e 120º dia do pós-operatório. Fragmentos da parede abdominal dos animais foram submetidos à análise tensiométrica. Resultados: A tensiometria aos 30dias mostrou maior resistência do tecido com tela Bard Soft® em relação à de Prolene®; no 60º dia a Bard Soft® manteve a resistência superior ao Prolene®; no 120º dia a reparação com tela macroporosa Ultrapro® mostrou-se mais resistentes que a de Prolene® e Bard Soft®. Conclusão: Os tecidos reparados com telas macroporosas demonstraram maior resistência do que as microporosas em todas as fases, sendo que aos 120 dias de pós-operatório a Ultrapro® teve melhor desempenho que as demais.

Comparative study between polypropylene and polypropylene/poliglecaprone meshes used in the correction of abdominal wall defect in rats / Estudo comparativo entre as telas de polipropileno e polipropileno/poliglecaprone utilizadas na correção de defeito na parede abdominal ventral de ratos

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 30th and 60th 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 30th (A30 and B30) and 60th 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 60th 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.

OBJETIVO: Avaliar a cicatrização de um defeito, na parede abdominal ventral de ratos, comparando-se as telas de polipropileno e polipropileno/poliglecaprone no 30º e 60º dia do pós-operatório. MÉTODOS: Trinta e dois ratos Wistar foram submetidos à produção de defeito na parede abdominal ventral, com integridade do peritônio parietal. Na correção foram utilizadas as telas de polipropileno (grupo A) e polipropileno/poliglecaprone (grupo B). Houve subdivisão em quatro subgrupos (A30, A60, B30 e B60) de oito animais que foram submetidos à eutanásia no 30º e 60º dia do pós-operatório. Fragmentos da parede abdominal foram submetidos à análise macroscópica, tensiométrica e histológica. RESULTADOS: A tensiometria no subgrupo A30 mostrou tensão média de ruptura de 0,78 Mpa e no subgrupo A60 de 0,66 MPa. No subgrupo B30 foi de 0,84 MPa e no B60 de 1,27 MPa. O escore do processo inflamatório mostrou fase subaguda nos subgrupos A30 e B30 e processo inflamatório crônico no subgrupo A60 e B60. CONCLUSÕES: A resistência à tensão foi maior na parede reparada pela tela de polipropileno/poliglecaprone no 60º dia pós-operatório. Na análise histológica houve maior concentração da fibrose na superfície da tela de polipropileno com tendência ao encapsulamento. Nos subgrupos polipropileno/poliglecaprone a análise histológica mostrou maior fibrose entre os filamentos da tela.