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Purpose: To evaluate the most frequent surgical techniques of high-risk colorectal anastomoses in rats. Methods: Wistar rats were enrolled in three different models comprising inflammatory (TNBS enema), vascular (portal vein occlusion) or obstructive (a non-ischemic constricting ring) mechanisms associated with colonic anastomosis that had accomplished after these former lesions. Histological analyses (Hematoxylin and eosin and Picrosirius red) were performed. Results: All anastomoses techniques were associated with risk factors and had complications, mainly anastomotic leakage. In Study 1, the use of a pharmacological agent, trinitrobenzene sulfonic acid (TNBS) mimicked an inflammatory bowel disease such as Crohns disease with 50% of anastomosis leakage, the higher percentage among all models tested. In Study 2, after portal ischemia followed by reperfusion it was observed a dense neutrophil infiltrate in the midst of necrotic tissue and fibrin at the anastomotic site and 5 days after the anastomosis, no collagen was produced. In Study 3, 5 days after the mechanical obstruction some denuded areas of epithelium with marked oedema of mucosa and submucosa were seen, at the anastomotic site and anastomosis group showed some reduction of collagen density when compared with Control/Sham group. Conclusion: All the experimental surgical techniques tested in rats were associated with high-risk colorectal anastomoses and were useful to study colonic anastomotic healing and intestinal leakage.(AU)

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PURPOSE: The controversy regarding whether loop ileostomy or loop transverse colostomy is a better method for temporary decompression of colorectal anastomosis motivated this review. METHODS: Five randomized trials were included, with 334 patients: 168 in the loop ileostomy group and 166 in the loop transverse colostomy group. The outcomes analyzed were: 1. Mortality; 2. Wound infection; 3. Time of stoma formation; 4. Time of stoma closure; 5. Time interval between stoma formation and closure; 6. Stoma prolapse; 7. Stoma retraction; 8. Parastomal hernia; 9. Parastomal fistula; 10. Stenosis; 11. Necrosis; 12. Skin irritation; 13. Ileus; 14. Bowel leakage; 15. Reoperation; 16. Patient adaptation; 17. Length of hospital stay; 18. Colorectal anastomotic dehiscence; 19. Incisional hernia; 20. Postoperative bowel obstruction. RESULTS: Stoma prolapse was statistically significant (p = 0.00001), but with statistical heterogeneity; the sensitive analysis was applied, excluding the trials that included emergency surgery, and this showed: p = 0.02, with I² = 0 percent for the heterogeneity test. CONCLUSIONS: The outcomes reported were not statistically or clinically significant except for stoma prolapse. Better evidence for making the choice between loop ileostomy or loop colostomy requires large-scale randomized controlled trials.(AU)

OBJETIVO: A controvérsia entre ileostomia em alça ou colostomia em alça como a melhor forma para a descompressão temporária da anastomose colorretal motivou a realização desta revisão. MÉTODOS: Cinco ensaios clínicos casualizados foram incluídos com 334 pacientes: 168 no grupo de ileostomia e 166 no grupo de colostomia. Os resultados analisaram: 1. Mortalidade; 2. Infecção da ferida; 3. Tempo de formação do estoma; 4. Tempo de fechamento do estoma; 5. Intervalo de tempo entre a formação e o fechamento do estoma; 6. Prolapso do estoma; 7. Retração do estoma; 8. Hérnia parastomal; 9. Fistula parastomal; 10. Estenose; 11. Necrose; 12. Irritação de pele; 13. Íleo; 14. Fístula entérica; 15. Reoperação; 16. Adaptação do paciente; 17. Tempo de internação hospitalar; 18. Deiscência da anastomose colorretal; 19. Hérnia de Incisional; 20. Obstrução intestinal pós-operatória. RESULTADOS: Prolapso do estoma: p = 0.00001, mas com heterogeneidade estatística; a análise de sensibilidade foi aplicada excluindo os estudos que incluíram cirurgias de emergência: p = 0.02 e teste de heterogeneidade: I²=0 por cento. CONCLUSÕES: Os resultados encontrados não foram estatística ou clinicamente significantes, exceto prolapso do estoma. A melhor evidência para a escolha entre ileostomia em alça ou colostomia em alça necessita de maior número de ensaios clínicos.(AU)

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PURPOSE: Hemorrhoids are a matter of concern due to a painful outcome. We describe a simple, easy and reliable experimental model to produce hemorrhoids in monkeys. METHODS: 14 monkeys (Cebus apella) were used. After general anesthesia, hemorrhoids were induced by ligation of the inferior hemorrhoidal vein, which is very alike to humans. The vein was located through a perianal incision, dissected and ligated with a 3-0 vicryl. The skin was sutured with a 4-0 catgut thread. Animals were kept in appropriate cages and evaluated daily. RESULTS: Nine days later there were hemorrhoidal piles in the anus in fifty percent (50 percent) of the animals. Outcome was unremarkable. There was no bleeding and all animals showed no signs of pain or suffering. CONCLUSION: This is an affordable and reliable experimental model to induce hemorrhoids for experimental studies.(AU)

OBJETIVO: Hemorróidas são objeto de preocupação devido à evolução dolorosa no pós-operatório. Descrevemos aqui um modelo experimental simples e confiável de indução de hemorróidas em macacos. MÉTODOS: 14 macacos-prego (Cebus apella) foram empregados. Após anestesia geral induziu-se a formação de hemorróidas pela ligadura da veia hemorroidária inferior, que é muito parecida com a de humanos. A veia foi localizada através de uma incisão perianal, dissecada e ligada com fio de vicryl 3-0. A pele foi suturada com fio de categute 4-0. Os animais foram mantidos em jaulas apropriadas e avaliados diariamente. RESULTADOS: Nove dias após o procedimento havia mamilos hemorroidários em cinqüenta por cento (50 por cento) dos animais. Não houve intercorrências no pós-operatório. Não houve sangramento ou sinais de dor ou de sofrimento. CONCLUSÃO: Este é um modelo viável e confiável para induzir hemorróidas para estudos experimentais.(AU)

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