The effect of Allium sativum in experimental peritoneal adhesion model in rats

Abstract Purpose: To evaluate the effect of garlic on formation of postoperative adhesions in rats. Methods: Twenty-four Sprague dawley rats were divided into three groups. In Group 1 (sham), laparotomy was performed and stitched up. In Group 2 (control), after laparotomy was performed, punctate hemorrhage was induced by cecal abrasion in the cecum and 2 cc of saline was intraperitoneally administered to each rat. In Group 3 (experimental), after laparotomy was performed, punctate hemorrhage was induced by cecal abrasion in the cecum and each rat was intraperitoneally administered a sterile Allium sativum derivative. The rats in all groups were re-laparotomized on postoperative day 7; samples were obtained from the peritoneal tissue surrounding the cecum Results: In Group 3, there was a statistically significant difference in terms of inflammation, lymph node size, and free oxygen radicals; these parameters tended to increase. In terms of fibrosis evaluated using H&E and MT, there was no significant difference between groups 2 and 3. Conclusions: No positive outcomes indicating that Allium sativum reduces intra-abdominal adhesions were obtained. However, it caused severe inflammation in the tissue. Additionally, in immunohistochemical analyses conducted to detect oxidative stress, allium sativum increased the production of free oxygen radicals in the tissue.

The effect of pycnogenol on lymphatic nodes and adhesion during in a peritoneal adhesion model in rats

Abstract Purpose: To investigate the effects of pycnogenol on peritoneal adhesions and additionally to investigate the immunohistochemical effects of free oxygen radicals and reactive lymph nodes detected in the adhesive tissue that was sampled surrounding the cecum on intra-abdominal adhesions. Methods: Twenty-seven Wistar Albino rats were divided into three groups. In group 1 (sham), laparotomy was performed and stitched up. In group 2 (control), after laparotomy was performed, punctate hemorrhage was induced by cecal abrasion in the cecum and each rat was intraperitoneally administered 2 cc of saline. In group 3 (experimental), after laparotomy was performed, punctate hemorrhage was induced by cecal abrasion in the cecum and each rat was intraperitoneally administered a sterile Pycnogenol derivative. The rats in all groups were re-laparotomized on postoperative day 7; samples were obtained from the peritoneal tissue surrounding the cecum, and the rats were sacrificed. Results: In group 3, there was a statistically significant difference in terms of inflammation, lymph node size, and free oxygen radicals; these parameters tended to increase. In terms of fibrosis evaluated using H&E and MT, there was no significant difference between groups 2 and 3. Conclusions: No positive outcomes indicating that pycnogenol reduces intra-abdominal adhesions were obtained. However, it caused severe inflammation in the tissue. Moreover, a significant increase in lymph node size was detected secondary to inflammation. Additionally, in immunohistochemical analyses conducted to detect oxidative stress, pycnogenol increased the production of free oxygen radicals in the tissue.

Comparative study of polyglactin 910 and simple catgut in the formation of intraperitoneal adhesions

Abstract Purpose: To compare polyglactin 910 and simple catgut sutures for the incidence of intraperitoneal adhesions. Methods: Twenty female Wistar rats were placed into two groups. Group 1 received ischemic sutures and Group 2 received polyglactin 910. Five sutures inductive of adhesions in each rat were made. After 14 days, the rats were euthanized with an assessment of the presence of adhesions, the number of sutures involved and classification according to the Granat et al. scale described by Ozel et al17. Results: In total, 19 of the 20 rats presented adhesions, with nine from Group 1 and ten from Group 2. There was a smaller number of affected sutures in Group 1, while in Group 2 the majority of the sutures formed adhesions (p=0.0197). According to the Granat et al. scale, Group 1 predominately developed fine, filamentous adhesions or thickening in a restricted area. Group 2 mainly presented extensive, thick adhesions with the involvement of the viscera (p=0.0055). Conclusion: Polyglactin 910 sutures formed more adhesions that were more extensive and thicker than the simple catgut sutures.

Aderências em telas de polipropileno versus telas Sepramesh®: estudo experimental em ratos / Adhesions on polypropylene versus Sepramesh® meshes: an experimental study in rats

RESUMO Objetivo: comparar a formação de aderências intraperitoneais, induzidas em ratos, quando utilizadas as telas de polipropileno e Sepramesh®. Métodos: foram utilizados 20 ratos Wistar, machos, agrupados randomicamente em dois grupos de dez animais cada. Duas telas de dimensão 10x20mm foram dispostas intraperitonealmente em cada animal, uma de polipropileno (PP) e a outra Sepramesh®. No Grupo 1, a tela de polipropileno foi posicionada à direita e a tela Sepramesh® à esquerda. No Grupo 2, a disposição das telas foi invertida. Após 14 dias do procedimento, os animais foram eutanasiados e a incorporação e a porcentagem de aderências, em cada tela, analisadas macroscopicamente. Os dados coletados foram submetidos à análise estatística com nível de significância adotado de p<0,05. Resultados: todas as telas apresentaram aderências. Nas telas Sepramesh®, a porcentagem de superfície coberta por aderências variou entre 2% e 86%, com média de 18,6±18,6%, enquanto que, nas telas de polipropileno, variou entre 6% e 86%, com média de 57,4%±34,9% (p<0,05). Os sítios preferenciais de formação de aderências, em ambas as telas, foram as bordas. Conclusão: embora nenhuma tela tenha sido capaz de inibir completamente o desenvolvimento de aderências, a tela Sepramesh® apresentou menos aderências em relação à tela de polipropileno. A preferência da formação de aderências nas bordas das próteses evidencia a importância da fixação adequada das telas.

ABSTRACT Objective: to compare the formation of induced intraperitoneal adhesions in rats when using polypropylene and Sepramesh® meshes. Methods: we used 20 male Wistar rats, randomly grouped in two groups of ten animals each. We arranged two 10x20mm meshes intraperitoneally into each animal, one being the polypropylene (PP), and the other, Sepramesh®. In Group 1, the polypropylene mesh was positioned to the right, and the Sepramesh®, to the left. In Group 2, the meshes' layout was reversed. After 14 days of the procedure, we euthanized the animals and analyzed the incorporation and percentages of adhesions macroscopically in each mesh. We submitted the collected data to statistical analysis with a significance level of 5% (p<0.05). Results: all meshes showed adhesions. In the Sepramesh® ones, the percentage of surface covered by adhesions ranged from 2% to 86%, with a mean of 18.6±18.6%, while in the polypropylene meshes, it varied between 6% and 86%, with an average of 57.4%±34.9% (p<0.05). The preferred adhesion sites on both meshes were the edges. Conclusion: although no mesh was able to completely inhibit the development of adhesions, the Sepramesh® mesh presented less adhesions to the polypropylene mesh. The most common sites of adhesion formation were the edges of the prosthesis, which evidences the importance of the adequate fixation of the meshes.

Comparative study of intraperitoneal adhesions related to light-weight polypropylene mesh and type I polymerized and purified bovine collagen coated light-weight polypropylene mesh in rabbits

Abstract Purpose: To compare the effectiveness of light-weight polypropylene mesh coated with polymerized and purified bovine type I collagen (Surgidry HNB) in the treatment of abdominal wall defect and the degree of adhesion formation. Methods: Two types of polypropylene mesh were implanted after creation of defect measuring 6.0cm X 5.5cm in the anterior abdominal wall of 32 male New Zealand breed rabbits, divided in two groups (n = 32): (1) light-weigh macroporous polypropylene, (2) type I polymerized and purified bovine collagen coated light-weigh macroporous polypropylene. These animals were further accessed for adhesions, histological evaluation of inflammation and wall's thickness. Results: The percentage of the area adhered in group 1 (62.31 ± 16.6) was higher compared to group 2 (22.19 ± 14.57) (p <0.05). There was an association between the percentage of the covered area by adhesions and the type of adhesion, toughness and the scores obtained by the adhesion score by correlation analysis (p <0.05). There was no difference between the groups in any variables in relation to the degree of inflammation. Conclusion: The purified type I bovine collagen coated light-weigh polypropylene mesh showed to be effective in the repair of abdominal wall defects and reducing adhesion formation.

The effectiveness of heparin, platelet-rich plasma (PRP), and silver nanoparticles on prevention of postoperative peritoneal adhesion formation in rats

Abstract Purpose: To assess the effectiveness of heparin, platelet-rich plasma (PRP), and silver nanoparticles on prevention of postoperative adhesion in animal models. Methods: Sixty males Albino Wistar rats aged 5 to 6 weeks were classified into five groups receiving none, heparin, PRP, silver nanoparticles, PRP plus silver nanoparticles intraperitoneally. After 2 weeks, the animals underwent laparotomy and the damaged site was assessed for peritoneal adhesions severity. Results: The mean severity scores were 2.5 ± 0.9, 2.16 ± 0.7, 1.5 ± 0.5, 2.66 ± 0.88, and 2.25 ± 0.62 in the control, heparin, PRP, silver and PRP plus silver groups, respectively with significant intergroup difference (p = 0.004). The highest effective material for preventing adhesion formation was PRP followed by heparin and PRP plus silver. Moreover, compared to the controls, only use of PRP was significantly effective, in terms of adhesion severity (p = 0.01) . Conclusion: Platelet-rich plasma alone may have the highest efficacy for preventing postoperative peritoneal adhesions in comparison with heparin, silver nanoparticles and PRP plus silver nanoparticles.

Dexamethasone and sodium carboxymethyl cellulose prevent postoperative intraperitoneal adhesions in rats

We aimed to evaluate the effects of the barrier agent sodium carboxymethyl cellulose (SCMC) with and without dexamethasone for the prevention of postoperative adhesion formation in a rat model of postoperative peritoneal adhesion. A total of 160 three-month old male and female Wistar rats underwent a laparotomy, and adhesions were induced by ileocecal abrasion. Rats were randomly assigned to 4 groups (n=40 each): group A, untreated; group B, treated with SCMC only; group C1, treated with SCMC + 3 mg dexamethasone, and group C2, treated with SCMC + 8 mg dexamethasone. After 12 days, adhesion formation and histopathological changes were compared. In groups A, B, C1, and C2, the mortality rates were 10, 5, 5, and 5%, respectively. In groups C1 and C2, the adhesions were filmy and easy to dissect and were milder compared with those in groups A and B. The total adhesion score in group C1 (3.38±0.49) was significantly lower than that of group B (6.01±0.57; P<0.01) or group A (8.01±0.67; P<0.05). There was no significant difference in adhesion formation between groups C1 and C2. Compared with groups A and B, groups C1 and C2 exhibited milder histopathological changes. SCMC in combination with dexamethasone can prevent adhesion formation and is a better barrier agent than SCMC alone. The safety and feasibility of SCMC in combination with dexamethasone to prevent adhesion formation after abdominal surgery warrants further clinical study.

Pode a tela de poliéster coberta com colágeno diminuir as taxas aderências intraperitoneais na correção de hérnia incisional? / May polyester with collagen coating mesh decrease the rate of intraperitoneal adhesions in incisional hernia repair?

RACIONAL: Entre as telas utilizadas na reparação de hérnias incisionais na técnica aberta, a de polipropileno é a mais utilizada devido à flexibilidade, estimulação do crescimento celular, resposta inflamatória satisfatória, fácil manipulação e baixo preço. No entanto, induz a formação de aderências, quando em contato com os conteúdos intra-abdominais. OBJETIVO: Avaliar as aderências formadas após a colocação intraperitoneal da tela de polipropileno e a tela de poliéster coberta com colágeno. MÉTODO: Foram utilizadas 26 ratas Wistar fêmeas, randomizadas em três grupos. No grupo 0 (sham) não houve colocação de prótese, apenas laparotomia; no grupo 1 foi implantada a prótese de polipropileno na superfície peritoneal; e no grupo 2, a prótese composta por poliéster coberta por colágeno. Todos os animais foram mortos 21 dias após o procedimento e avaliados quanto às vísceras envolvidas nas aderências, grau das aderências, percentual da tela acometimento por aderências e a força necessária para a sua ruptura. RESULTADOS: Não houve diferença de peso entre os grupos. O grupo 0 não apresentou aderência. Os grupos 1 e 2 apresentaram aderências na superfície da prótese, predominante no omento. O grau de aderências, superfície acometida não teve diferença representativa entre os grupos. A cobertura de colágeno não demonstrou aderências. As aderências ocorreram na borda livre da tela, em contato com a face de poliéster. Análise do tipo de superfície comprometida por aderências, o grupo polipropileno teve 80% e o grupo poliéster com colágeno apenas 10% (p<0,005). CONCLUSÃO: Para os parâmetros avaliados aderência, grau e força máxima de ruptura não houve diferença. No entanto, a tela de polipropileno teve superfície acometida pela aderência significativamente maior em relação à tela de poliéster protegida com colágeno.

BACKGROUND: Among meshes used in incisional hernias in open technique repair, the polypropylene is the most commonly used due to flexibility, cellular growth stimulation, satisfactory inflammatory response, easy manipulation and low price. However, it induces adhesions formation when in contact with the intra-abdominal contents. AIM: To evaluate the formation of adhesions after polypropylene and collagen coated polyester mesh with intraperitoneal placement. METHODS: Twenty six female Wistar rats were randomized in three groups. In the group 0 (sham) there was no prosthesis placement, in the polypropylene (group 1) the prosthesis was placed at the peritoneal surface and in the group 2, collagen coated polyester mesh was placed. The rats were killed on postoperative day 21 to evaluate adhesions regarding its degree, mesh percentage of involvement, bowel involvement and strength needed to cause rupture. RESULTS: There was no difference in weight between groups. The group 0 did not develop any adhesions. The groups 1 and 2 developed prosthetic mesh surface adhesions, mostly in the omentum. There was no difference in adhesion degree and percentage of surface involvement between groups. The collagen coated mesh did not develop adhesions. The adhesions occurred at the free edge of the mesh, in contact with the polyester. The Polypropylene group presented 80% of the surface involved with adhesions, while the collagen coated polyester group presented 10% (p<0,005). CONCLUSION: There was no difference between adhesion, degree of adhesion and strength needed to cause rupture. However, the polypropylene mesh presented significantly higher surface of adhesion when compared to the collagen coated polyester mesh.

Adhesion-preventing properties of 4% icodextrin and canola oil: a comparative experimental study

OBJECTIVE: Postsurgical abdominal adhesions are common, serious postoperative complications. The present study compared the usefulness of 4% icodextrin and canola oil in preventing postoperative peritoneal adhesions. METHODS: Twenty-four Wistar albino rats were divided into three groups. Following a laparotomy, a serosal abrasion was made by brushing the cecum, and 3 mL of 0.9% NaCl, 4% icodextrin, or 3 mL of canola oil were intraperitoneally administered for the control, icodextrin, and canola oil groups, respectively. The abdomen was then closed. All of the rats were sacrificed at day 10. Macroscopic, histopathological, and biochemical evaluations were performed. The results were statistically analyzed using Kruskal-Wallis and ANOVA tests. RESULTS: Macroscopic analyses revealed that both canola oil and 4% icodextrin reduced adhesion formation, but the difference was not statistically significant (p = 0.17). The histopathological examinations revealed no significant differences in terms of giant cell, lymphocyte/plasmocyte, neutrophil, ICAM1, or PECAM1 scores. However, both canola oil and 4% icodextrin significantly reduced fibrosis (p = 0.025). In the canola oil group, the histiocytic reactions were significantly increased (p = 0.001), and the hydroxyproline levels were significantly lower than those in the other groups (p = 0.034). CONCLUSIONS: In the present study, canola oil was determined to be superior to 4% icodextrin in lowering hydroxyproline levels and increasing histiocytic reactions. Considering these results, we believe that canola oil is a promising agent for preventing adhesion formation.

Efetividade do uso combinado de filme de ácido lático e tela de polipropileno na formação de aderências intraperitoneal: um modelo experimental em ratos / Effectiveness of the combined use of lactic acid film and polypropylene mesh in the formation of intraperitoneal adhesions: an experimental model in rats

OBJETIVO: Avaliar a eficácia do uso de um biomaterial de ácido lático (SurgiWrap®) como protetor de tela de polipropileno (Marlex®) em relação à formação de aderências intraperitoneais em ratos. MÉTODO: Quarenta ratas Wistar formaram os grupos a seguir: Grupo 0 (Sham) - apenas laparotomia; Grupo I - tela de polipropileno; Grupo II - tela de polipropileno protegida por filme de ácido lático. Estes animais foram operados com laparotomia e colocação das telas no fechamento. Após 21 dias foram sacrificados para análise aderencial quanto ao tipo (0 a 3), porcentagem de área acometida e força necessária para rompimento. RESULTADOS: O Grupo 0 não apresentou aderências intraperitoneais. Em relação à classificação foi evidenciado a maior prevalência de aderências tipo 3 em ambos os grupos. Quanto à força para ruptura aderencial o Grupo 1 obteve média de 1,58 N e o Grupo 2 de 1,23 N. A tela foi envolvida por aderências em mais de 50 por cento da área de sua superfície em 87 por cento no Grupo 1 e 84 por cento no Grupo 2. Por diferentes métodos estatísticos constatou-se que não houve diferença significativa entre os grupos nas variáveis estudadas. CONCLUSÃO: A utilização do combinado tela de polipropileno e bioprotetor de ácido lático demonstrou índices semelhantes em relação à formação de aderências intraperitoneais quando comparada ao uso individual da mesma tela.

OBJECTIVE: To evaluate the efficacy of a lactic acid biomaterial (SurgiWrap®) as a protector of the polypropylene mesh (Marlex®) regarding the formation of intraperitoneal adhesions in rats. METHODS: Forty Wistar rats formed the following groups: Group 0 (Sham) - only laparotomy; Group I - polypropylene mesh; Group II - polypropylene mesh protected by a film of lactic acid. These animals were submitted to laparotomy and placement (or not) of the meshes at closing. After 21 days they were sacrificed for analysis of the adhesion type (0-3), percentage of affected area and strength needed to rupture. RESULTS: Group 0 showed no intraperitoneal adhesions. Regarding classification, type 3 adhesions had the highest prevalence in both groups 1 and 2. As for the strength to break adhesions, Group 1 had an average of 1.58 N and Group 2, 1.23 N. The mesh was surrounded by adhesions in more than 50 percent of their surface area in 87 percent of Group 1 subjects and in 84 percent of Group 2 individuals. Through different statistical methods we found that there was no significant difference between groups for both variables. CONCLUSION: The combined use of polypropylene mesh and lactic acid bioprotector showed similar results in relation to intraperitoneal adhesion formation when compared to the sole use of the same mesh.

Prevención de adherencias peritoneales postoperatorias mediante uso de antagonista de receptores de neurokinina tipo 1 / Peritoneal adhesions prevention: neurokinin-1 receptor antagonist

Background: The fibrinolytic activity plays an important role in Peritoneal Adhesions (PA) develop-ment. It's well known that de substance P decreased the fibrinolysis by binding the neurokinin-1 receptor, improving the PA formation. Objectives: To evaluate the effectiveness of intraperitoneal treatment with a Neurokinin-1 receptor antagonist (NK-R1A) in peritoneal adhesión prevention in animal model. Materials and Methods: In 40 male wistar rats, PA were induced, and then randomly assigned to 2 groups: A group treated with Aprepitant (NK-Rl A), and a control group. The animals were killed at 7 or 14 postoperative day, and the number, severity and histopathology of PA were evaluated. Results: NK-Rl A decreased the number (40 percent less) and severity (p = 0.001) of PA when compare to control group. The NK-Rl A group had less PA in manipulated and no manipulated organs during surgery. Besides presented less fibrosis (p = 0.001), less inflamation (p = 0.005) and less vascular proliferation (p = 0.047) than control group. Conclusions: The NK-Rl A is effective as in PA prevention.

Introducción: La actividad fibrinolítica juega un papel fundamental en el desarrollo de las adherencias peritoneales (AP), y se conoce que la Sustancia P al actuar sobre receptores de neurokinina tipo 1 a nivel peritoneal, disminuye la fibrinólisis, favoreciendo la formación de las mismas. Objetivos: Evaluar la efectividad del tratamiento intraperitoneal con antagonista de receptores 1 de neurokinina (NK-R1A) en la prevención de AP en modelo animal. Materiales y Métodos: A 40 ratas wistar se les practicó cirugía formadora de AP y fueron distribuidas de forma aleatoria en 2 grupos, un grupo que recibió Aprepitant (NK-R1A), y el otro como grupo control. Los animales fueron sacrificados a los 7 ó 14 días, y se evaluó el número, severidad e histopatología de las AP. Resultados: El NK-Rl A disminuyó el número (40 por ciento menos) y severidad de las AP (p = 0,001) en relación al grupo control y presentó menos AP en órganos manipulados y no manipulados durante la cirugía. Ademßs presentó menor grado de fibrosis (p = 0,001), menor inflamación (p = 0,005) y menor proliferación vascular (p = 0,047) que el grupo control. Conclusión: El tratamiento peritoneal con NK-R1A es eficaz en la prevención de la formación de AP.

Evaluation of peritoneal adhesions formation and tissue response to polypropylene - poli (2-hydroxyethyl methacrylate)-(polyHEMA) implant on rats' abdominal wall / Avaliação da formação de aderências peritoneais e da resposta tecidual ao implante de poli (2-hidroxietil dimetacrilato)-(poliHEMA) na parede abdominal de ratos

PURPOSE: To verify if the composit poli (2-hydroxyethyl methacrylate)-PolyHEMA/polypropylene mesh implanted in the female rat's abdominal wall could be suitable for the prevention of peritoneal adhesions, and for the evaluation of the tecidual response produced by this biomaterial. METHODS: Polypropylene meshes (Group PP, n=20) and polypropylene meshes coated with a layer of poli (2-hydroxyethyl methacrylate)-PolyHEMA (Group PH, n=20) were implanted on the abdominal wall of Wistar female rats. Ten animals from each group were submitted to euthanasia at 15 and 30 days of the postoperative period. RESULTS: The animals from the group PP presented visceral adhesions on the mesh surface, which was not observed in the ones from group PH. At the histopathological examination foreign body response was observed in both groups, whilst there was a greater intensity of inflammatory response in group PH on both moments. CONCLUSION: The poli (2-hydroxyethyl methacrylate) polyHEMA hydrogel associated to polypropylene mesh reduces visceral adhesion formation in rats, although it may be associated to greater inflammatory reaction.

OBJETIVO: Verificar se compósito poli 2-hidroxietil dimetacrilato (PoliHEMA) / tela de polipropileno implantado na parede abdominal de ratas seria adequado para prevenção de aderências peritoneais e avaliar a resposta tecidual desencadeada por este biomaterial. MÉTODOS: Foram implantadas telas de polipropileno - Grupo PP (n=20) e telas de polipropileno revestidas por uma camada de poli 2 (hidroxietil dimetacrilato)-PolyHEMA - Grupo PH (n=20) na parede abdominal de ratas da linhagem Wistar. Dez animais de cada grupo foram submetidos à eutanásia aos 15 e 30 dias de pós-operatório. RESULTADOS: Os animais do grupo PP apresentaram aderências viscerais na superfície da tela, o que não foi observado nos do grupo PH. Observou-se no exame histopatológico resposta tipo corpo estranho nos dois grupos sendo que no grupo PH houve maior intensidade de resposta inflamatória nos dois momentos. CONCLUSÃO: O hidrogel de poliHEMA quando associado à tela de polipropileno reduz a formação de aderências viscerais em ratos, embora possa estar associado à reação inflamatória mais intensa.

2-hydroxyethyl methacrylate composite - polypropylene mesh for preventing peritoneal adhesions in female dogs / Compósito 2-hidroxietil dimetacrilato-tela de polipropileno para prevenção de aderências peritoneais em cadelas

PURPOSE: To evaluate whether the lining facing the visceral side of polypropylene mesh made with 2-hydroxyethyl methacrylate (p(HEMA)) hydrogel could avoid peritoneal adhesion in female dogs. METHODS: Eight animals (group PP) had a polypropylene mesh implanted to correct a defect in the rectal abdominal muscle, whereas in the other group (group PH) the polypropylene mesh was coated with p(HEMA) composite on the surface facing the peritoneal area. RESULTS: Adhesions were observed on the mesh in 62.5 percent of the PP group. In the PH group adhesions were present only on the suture lines. CONCLUSION: p(HEMA) hydrogel was well tolerated and effective in avoiding visceral and omental adhesions on the surface of the polypropylene mesh.

OBJETIVO: Avaliar se o revestimento da face visceral de uma tela de polipropileno com 2-hidroxietil dimetacrilato (p(HEMA)) poderia evitar aderências peritoniais em cadelas. MÉTODOS: Em oito animais (Grupo PP) foram implantadas telas de polipropileno para correção de um defeito do músculo reto abdominal, enquanto em outro grupo (Grupo PH) fez-se a implantação de uma tela de polipropileno cuja face peritonial foi revestida por 2-hidroxietil dimetacrilato (p(HEMA)). RESULTADOS: Foram observados 62,5 por cento de aderências peritoniais sobre a tela nos animais do Grupo PP, enquanto que no Grupo PH estas não ocorreram, exceto sobre a linha se sutura. CONCLUSÃO: O hidrogel de p(HEMA) foi bem tolerado pelos animais e mostrou-se efetivo na prevenção das aderências viscerais e omentais sobre a tela de polipropileno.

Polylactic acid film versus acellular porcine small intestinal submucosa mesh in peritoneal adhesion formation in rats / Filme ácido poli-lático versus tela de submucosa intestinal suína na formação de aderências peritoneais em ratos

PURPOSE: To assess intraperitoneal adhesion formation in rats after the single implantation of intraperitoneal polypropylene mesh versus SIS mesh, and the effect of PAF as a polypropylene mesh barrier. METHODS: A total of 55 albino rats randomized into three groups were assessed. The type of adhesions, the percentage of mash covered with adhesions, and the rupture strength of the adhesions were evaluated. RESULTS: The type 2 and 3 adhesions were more frequent in group 1 (polypropylene mesh) and group 3 (Polypropylene+PAF), while type 0 and 1 adhesions were more frequent in group 2 (SIS). The mean rupture strength was 1,58 N (±0,719N) in group 1, 0,42 N (±0,432N) in group 2 and 1,23 N (±0,432N) in group 3. Over 50% of the mash was covered with adhesions in 12 (80%) cases of the group 1, in 4 (20%) cases of the group 2 and in 16 (84,2%) cases of the group 3. Group 2 differed significantly (p<0.001) from the other groups. CONCLUSIONS: Implantation of intraperitoneal polypropylene mesh yielded higher rates of adhesion and the use of PAF as a mesh barrier didn't reduced the rates of adhesion. SIS mesh implantation revealed lower rates of peritoneal adhesions.

OBJETIVO: Avaliar a formação de aderência intraperitoneal em ratos após o implante peritoneal da tela de polipropileno comparada à tela de SIS, e o efeito do PAF como barreira anti-aderente à tela de polipropileno. MÉTODOS: 55 ratos albinos foram randomizados em três grupos. O tipo de aderência, o percentual de tela coberta por aderência, e a força de rupturas das aderências foram avaliadas. RESULTADOS: Os tipos de aderência 2 e 3 foram mais freqüentes no grupo 1 (polipropileno) e no grupo 3 (polipropileno+PAF); as do tipo 0 e 1 foram mais freqüentes no grupo 2 (SIS). A força media de ruptura foi de 1,58N (±0,719N) no grupo 1, 0,42N (±0,432N) no grupo 2 e 1,23N (±0,432N) no grupo3. Mais de 50% da tela estava coberta por aderências em 12 (80%) casos do grupo 1, em 4 (20%) casos do grupo 2 e em 16 (84,2%) casos do grupo 3. O grupo 2 foi significativamente diferente (p<0.001) dos outros grupos. CONCLUSÕES: O uso intraperitoneal da tela de polipropileno levou a elevados índices de aderência, e o uso de PAF como barreira anti-aderente não reduziu os índices de aderência. O implante intraperitoneal de SIS revelou índices baixos de aderências peritoneais.

Reduction of postsurgical adhesions in a rat model: a comparative study

BACKGROUND: Adhesion formation after peritoneal surgery is a major cause of postoperative bowel obstruction, infertility, and chronic pelvic pain. In this study, we compared the possible individual effects of phosphatidylcholine (PC), Seprafilm® II, and tissue plasminogen activator (t-PA) and the combined effects of phosphatidylcholine and t-PA on postoperative adhesion formation in a rat surgical model. MATERIALS AND METHODS: A total of 50 Wistar male rats underwent median laparotomy and standardized abrasion of the visceral and parietal peritoneum. phosphatidylcholine, Seprafilm II, and t-PA alone and phosphatidylcholine and t-PA in combination were applied intraperitoneally at the end of the surgical procedure. Seven days after surgery, a relaparotomy was performed for adhesion grading and histopathological examination. RESULTS: A comparison of adhesion stages demonstrated a significant difference between the control group and the study groups (p<0.001). The adhesion grade of the combined treatment group was statistically different from that of the other groups (p<0.05). In the t-PA group and the combined group, six and two rats, respectively, developed hematomas locally on the cecum. CONCLUSIONS: PC, t-PA, and Seprafilm II used individually reduced the adhesion grade. The t-PA and phosphatidylcholine combination was most effective in reducing adhesion formation. On the other hand, usage of t-PA alone or in combination may increase risk of bleeding. More detailed studies are needed, and future studies on the efficacy of a material for decreasing adhesion formation should include a comparison of several control materials in the same model.

Preventing intraperitoneal adhesions with vitamin E and sodium hyaluronate/carboxymethylcellulose: a comparative study in rats

PURPOSE: To compare the effectiveness of intraperitoneally administered vitamin E with the sodium hyaluronate/carboxymethylcellulose membrane (HA/CBMC) in preventing postoperative intraperitoneal adhesion formation. METHODS: Sixty Wistar rats underwent a laparotomy and adhesions were induced (IA). The animals were divided into four groups: group 1, control (IA); group 2 (IA + Vitamin E): group 3 (IA+HA/CBMC) and group 4 (IA+ Vitamin E + HA/CBMC). The Vitamin E (groups 2 and 4) and HA/CBMC (groups 3 and 4) were administered intraperitoneally before the abdominal wall was closed. After 30 days, adhesions were classified by an independent surgeon. RESULTS: Three animals died; one from group 3 and two from group 4. All control animals had substantial adhesions compared with unsubstantial adhesions observed in 11/15 in group 2 (P = 0.000), 11/14 in group 3 (P = 0.001), and 10/13 in group 4 (P = 0.000). CONCLUSION: Vitamin E, administered intraperitoneally, is as effective as HA/CBMC in preventing postoperative adhesions.

OBJETIVO: Comparar a efetividade da Vitamina E e da membrana de Carboximetilcelulose/Hialuronato de Sódio (CBMC/HA) na prevenção da formação de aderências intraperitoneais pós-operatórias. MÉTODOS: Sessenta ratos Wistar foram submetidos à laparotomia para indução de aderências (IA) com abrasão do ceco seguido de aplicação de álcool absoluto e sutura com fio de seda no peritônio parietal. Os animais foram divididos em quatro grupos: 1 controle ( IA ); 2 ( IA + Vitamina E ); 3( IA + CBMC/HA ) e 4 ( IA + Vitamina E + CBMC/HA ). A Vitamina E ( grupos 2 e 4 ) e CBMC/HA ( grupos 3 e 4 ) foram administrados intraperitonealmente antes do fechamento da parede. Os ratos foram sacrificados em 30 dias e as aderências foram classificadas por cirurgião independente. Resultados: Três animais morreram, sendo um do grupo 3 e dois do grupo 4. Todos os animais do grupo controle ( 1 ) tiveram aderências substanciais, comparados com aderências insubstanciais em 11/15 no grupo 2 ( p = 0,000 ), 11/14 no grupo 3 ( p = 0,001 ) e 10/13 no grupo 4 ( p = 0,000 ). CONCLUSÃO: A Vitamina E administrada de maneira intraperitoneal é tão eficaz quanto a CBMC/HA na prevenção da formação de aderências pós-operatórias.

Effect of streptokinase in the prevention of intra-abdominal adhesions in the rat

The objective of the present study was to assess the action of streptokinase, a streptococcal derivative with fibrinolytic capacity, in the prevention of intraperitoneal adhesions in rats. Eighty animals were divided into four groups of 20 each; group A (control) received isotonic saline by the intraperitoneal route, group B received streptokinase by the intraperitoneal rout at the dose of 60.000 units/kg body weight diluted in 2 ml isotonic saline, group C received 60.000 streptokinase units diluted in 1 ml isotonic saline by the intravenous route, and group D received 30.000 streptokinase units in 2 ml isotonic saline by the intraperitoneal route and 30.000 streptokinase units diluted in 1 ml isotonic saline by the intravenous route. The animals were submitted at random to median laparotomy for the preparation of stitches inducing adhesions of the ischemic type according to the model of FERRAZ-NETO et al. (1991) modified, and sacrificed with a lethal dose of sulfuric ether on the 3rd and 7th postoperative day. Streptokinase was found to be effective in the prevention of adhesions when used by the intraperitoneal route (p=0,0349) or when administered both intraperitoneal and intravenously (p=0,0073). Comparison of the 3rd and 7the posteperative day within the same group showed no significant difference, suggesting that the drug acts during the early period of the healing process. We conclude that streptokinase is effective in the prevention of adhesion formation when used by the intraperitoneal route or by the combined intraperitoneal and intravenous routes at the dose employed in rats.

Formation and prevention of peritoneal adhesion - an experimental study on a rat model

Post operative peritoneal adhesions are always a threat and can cause adhesive obstruction and sterility in women due to tubal block. To study this problem, an experiment was conducted on 140 Swiss albino rats. Adhesions were produced in the animals by stripping the serosa of the caecum over an area of 2cm, a technique which resulted in about an 80% incidence of adhesions. Various substances like dextran, normal saline, honey, ghee, vitarnine E etc. were instilled into the peritoneal cavity. One group of 10 animals were fed on a diet containing a high dose of vitamin E. The animals' abdomens were opened on the 14th day and the adhesions were studied. Glove powder was instilled into the peritoneal cavity in one group of animals. For each group a control study was also done. Glove powder instillation invariably produced adhesions. Dextran and normal saline failed to prevent adhesions. Serosal application of Vitamin E produced granulomatous adhesions. Application of honey and ghee produced flimsy insubstantial adhesions. A high dose of oral Vitamin E also produced insubstantial adhesions. In the control group where the serosa was stripped and no substance was used, substantial adhesions were formed in a majority of the animals. From this experimental study, it was found that, vitamin E given orally in a high dose and serosal application of honey ghee mixture may be useful in minimising post operative peritoneal adhesions

Efeitos do diclofenaco potássico na profilaxia da formaçäo de aderências peritoneais: estudo experimental em ratos / Potassium diclofenac effects in the prevention of peritoneal adhesions formation: experimental study in rats

Com o objetivo de analisar a açao do diclofenaco potássico na profilaxia da formaçao de aderências peritoneais, 35 ratos, fêmeas, Wistar-Tecpar, com idade compreendida entre 120 e 150 dias e peso médio de 250 gramas, foram operados e divididos aleatoriamente em três grupos. Os animais do grupo A, em número de 15, serviram de controle para o experimento e receberam 2,00 ml de soluçao fisiológica a O,9 por cento por via intraperitoneal. Os dos grupos B e C, em número de dez animais cada, serviram de experimento. No grupo B, utilizou-se O,50 mg de diclofenaco de potássio em 2,00 ml de água destilada e no grupo C, 5,00 mg de diclofenaco de potássio no mesmo veículo e via de administraçao. Induziram-se as aderências pelo método de Ferraz Neto e col e realizaram-se as aferiçoes no 14o. dia de pós-operatório. Com relaçao ao número de pontos isquêmicos envolvidos com aderências e aderências peritoneais formadas, nao houve diferença significante entre os dois grupos. Conclui-se que a droga testada nao é eficiente na prevençao da formaçao de aderências peritoneais, em ratas, nas doses utilizadas.