Efeitos do dióxido de carbono e da pressão intra-abdominal na cicatrização de anastomoses colônicas : estudo experimental em ratos

Tese (doutorado)—Universidade de Brasília, Programa de Pós-Graduação em Ciências Médicas, 2013.Introdução: A cirurgia laparoscópica apresenta diversas vantagens em relação a cirurgia aberta, sendo cada vez mais utilizada. Para prover exposição cirúrgica é utilizado pneumoperitônio com dióxido de carbono (CO2), gerando aumento da pressão abdominal. O CO2 é utilizado em diversas especialidades médicas para melhorar o processo cicatricial. Os possíveis efeitos benéficos deste gás na cirurgia laparoscópica motivou este estudo. Objetivo: Verificar os efeitos do CO2 e da pressão abdominal na cicatrização de anastomoses colônicas em ratos. Material e método: 70 ratos foram distribuídos em 4 grupos. Foi realizada uma ressecção de segmento colônico proximal à reflexão peritoneal com anastomose colônica término-terminal vídeo-assistida, utilizando um novo modelo experimental, com pneumoperitônio nas pressões de 5 mmHg (grupo I), 12 mmHg (grupo II) ou 20 mmHg (grupo III). A mesma operação foi realizada por laparotomia (grupo IV). Os animais dos grupos I, II e III foram divididos em subgrupos para uso de CO2 ou hélio para confecção do pneumoperitônio. Os animais foram mortos após 7 dias. Foram avaliados os seguintes parâmetros: óbito, peso, achados intra-operatórios, pressão de ruptura da anastomose, força de ruptura da anastomose, características histopatológicas, histomorfometria do colágeno, dosagem de hidroxiprolina, fator de crescimento vascular endotelial (VEGF) e densidade de microvasos (CD31). Resultados: A pressão e os gases não influenciaram nos óbitos, nos achados intraoperatórios, na pressão de ruptura da anastomose, na força de ruptura da anastomose, na histopatologia, na dosagem de hidroxiprolina, no VEGF e no CD31. Há uma maior perda de peso na pressão de 20 mmHg em relação a cirurgia aberta (p=0,037). Na histomorfometria, o CO2 aumentou o percentual de colágeno em relação ao hélio na pressão de 20 mmHg (p=0,004). Conclusão: O CO2 não influenciou na cicatrização de anastomoses em cólon esquerdo de ratos nas pressões de 5 mmHg e 12 mmHg. Na pressão de 20 mmHg, o CO2 aumentou o percentual do colágeno na região anastomótica em relação ao hélio. _______________________________________________________________________________________ ABSTRACTIntroduction: Laparoscopic surgery has several advantages over open surgery, being increasingly used. Pneumoperitoneum with carbon dioxide (CO2) is used to provide surgical exposure, increasing abdominal pressure. CO2 is used in various medical specialties to improve the healing process. The possibility of beneficial effects caused by this gas in laparoscopic surgery motivated this study. Objective: To investigate the effects of CO2 and abdominal pressure on the healing of colonic anastomosis in rats. Methods: 70 rats were divided in 4 groups. We performed a video-assisted resection of a colonic segment proximal to the peritoneal reflection with an endto- end colonic anastomosis, using a new experimental model, at pneumoperitoneum pressures of 5 mmHg (group I), 12 mmHg (group II) or 20 mmHg (group III). The same operation was performed by laparotomy (group IV). The animals in groups I, II and III were divided into subgroups to use CO2 or helium for pneumoperitoneum. The animals were killed after 7 days. We evaluated the following parameters: mortality, weight, intraoperative findings, bursting pressure, breaking strength, histopathologic features, histomorphometry of collagen, serum hydroxyproline, vascular endothelial growth factor (VEGF) and microvessel density (CD31). Results: Neither the pressure nor the gas influenced in mortality, intraoperative findings, bursting pressure, breaking strength, histopathology, VEGF and CD31. There was a greater weight loss in pneumoperitoneum pressure of 20 mmHg compared to open surgery (p=0.037). In histomorphometry, the CO2 increased the percentage of collagen in relation to helium at a pressure of 20 mmHg (p=0.004). Conclusion: The CO2 had no effect on anastomotic healing in the left colon of rats at pressures of 5 mmHg and 12 mmHg. At a pressure of 20 mmHg, CO2 increased the percentage of collagen in the anastomosis compared to helium

Anal cancer and sexually transmitted diseases: what is the correlation?

OBJETIVO: O Câncer Anal é um tumor raro, cuja incidência é influenciada pelo comportamento sexual. O objetivo do trabalho é verificar a correlação entre o Câncer Anal e as Doenças Sexualmente Transmissíveis, como HPV, HIV, Infecção Gonocócica, Infecção por Clamídia, Sífilis e outras. MÉTODOS: Foram pesquisadas no site do Datasus as internações por Câncer Anal, HPV, HIV, Infecção Gonocócica, Infecção por Clamídia, Sífilis e outras DSTs, no SUS no Brasil, entre 1998 e 2007. O teste de correlação de Pearson foi aplicado. RESULTADOS: Há uma correlação positiva muito alta entre as internações por Câncer Anal e HPV (r = 0,98, p<0,001). Há uma correlação negativa entre as internações por Câncer Anal e as internações por Infecção Gonocócica (r = -0,81, p=0,005) e Infecção por Clamídia (r = -0,74, p=0,014). Não houve correlação estatisticamente significante entre Câncer Anal e as internações por HIV (r = 0,40, p=0,245), outras DSTs (r = 0,55, p=0,1) e Sífilis (r = -0,61, p=0,059). CONCLUSÃO: Há uma correlação positiva muito alta entre as internações por Câncer Anal e HPV no Brasil. Há uma correlação negativa entre as internações por Câncer Anal, Infecção Gonocócica e Infecção por Clamídia.OBJECTIVE: Anal Cancer is a rare tumor, which incidence is influenced by sexual behavior. The purpose of this paper is to verify the correlation between Anal Cancer and Sexually Transmitted Diseases, such as HPV, HIV, Gonococci Infection, Chlamydia Infection, Syphilis and others. METHODS: All the internments due to Anal Cancer, HIV, HPV, Syphilis, Gonococci Infection, Chlamydia Infection and other Sexually Transmitted Diseases in public healthy in Brazil were collected at Datasus site between 1998 and 2007. The Pearson correlation test was done. RESULTS: There was a high correlation between Anal Cancer and HPV admissions (r=0,98, p<0,001). There was negative correlation between Anal Cancer and Gonococci Infection admissions (r=-0,81, p=0,005) and Anal Cancer and Chlamydia Infection (r=-0,74, p=0,014). There was not statistic significant correlation between Anal Cancer and HIV admissions (r=0,40, p=0,245), between Anal Cancer and other Sexually Transmitted Diseases (r=0,55, p=0,1), and between Anal Cancer and Syphilis (r=-0,61, p=0,059). CONCLUSION: There was a high positive correlation between Anal Cancer and HPV admissions in Brazil. There were negative correlations between Anal Cancer and Gonococci Infection and between Anal Cancer and Chlamydia Infection admissions

The effect of carbon dioxide therapy on composite graft survival

PURPOSE: To investigate the effect of carboxytherapy in auricular composite grafts in rabbits. METHODS: An experimental study was conducted using 20 rabbits randomly assigned to a treatment group of carboxytherapy or a control group of saline solution. In each ear, a circular graft with 1.5 cm or 2 cm of diameter was amputated and reattached. Animals underwent carbon dioxide or saline injection four times during the experiment. We analyzed clinical evolution of the animals, grafts survival, histopathology features and histomorphometry of collagen. RESULTS:The treated group had a significantly lower weight gain (p=0.038). Histopathology was not significantly different between groups. There was an increase in amount of collagen in 2 cm grafts submitted to carbon dioxide therapy (p=0.003). Carboxytherapy didn't influence graft survival rate for 1.5 cm grafts or 2 cm grafts (p=0.567 and p=0.777, respectively). CONCLUSIONS:Carbon dioxide therapy increased the amount of collagen in 2 cm grafts. CO2 was not significantly different from saline infusion on composite grafts survival, but this study suggests that there is a mechanical effect caused by distension which favored graft survival

Effects of pneumoperitoneum with carbon dioxide and helium on renal function and morphology in rats

PURPOSE: To evaluate the effects of pneumoperitoneum with carbon dioxide and helium on renal function and morphology in a rat model. METHODS: Twenty four rats were randomized into three groups (n=8): gasless insufflation ('open', Pressure=0 mmHg), carbon dioxide pneumoperitoneum at 12 mmHg, and helium pneumoperitoneum at 12 mmHg; all lasting 90 minutes.. A cystostomy was performed and the bladder was emptied. At the end of the experiment, the urine produced, a blood sample and the left kidney of each animal were collected. The following variables were obtained: serum sodium, potassium, urea and creatinine, urine volume and creatinine. The creatinine clearance was estimated for each animal. The kidneys were stained with hematoxylin and eosin (HE) and evaluated by a pathologist blinded to the groups. RESULTS: The CO2 and Helium groups did not differ in the variables evaluated. Both developed oliguria (p<0.001 vs. gasless). The CO2 group presented hyperkalemia compared to gasless (p=0.05), which did not attain significance in the helium group. Histopathological analysis revealed mild hydropic degeneration and congestion in the three groups, with no significant difference among them. CONCLUSIONS: The type of gas resulted in no difference in the variables of renal function and morphology assessed. The increase in serum potassium was only observed with CO2 insufflation suggests a combined effect of elevated intra-abdominal pressure and metabolic effects of pneumoperitoneum

Colectomia videolaparoscópica : é seguro treinar o residente?

OBJETIVO: Cirurgia videolaparoscópica é a via preferencial para colectomias eletivas por ser um procedimento seguro, associado à menor tempo de internação, melhores resultados estéticos e por não influenciar negativamente os resultados oncológicos dos pacientes com câncer de cólon. Entretanto, ainda não existem dados consistentes sobre a segurança do treinamento em cirurgia laparoscópica durante a residência. Sendo assim, o objetivo deste estudo foi avaliar se a participação do residente em colectomias laparoscópicas afetou os resultados pós-operatórios. MÉTODOS: A base de dados do American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) foi pesquisada para colectomias laparoscópicas entre os anos de 2005 e 2007. A população do estudo foi dividida em dois grupos de acordo com a participação ou não do residente na cirurgia: residente vs. não residente. Os grupos foram comparados em relação às variáveis perioperatórias e complicações pós-operatórias. Uma análise multivariada foi realizada para investigar possível associação entre complicações pós-operatórias e o envolvimento de residentes na operação. RESULTADOS: A pesquisa retornou 5.912 pacientes, com mediana de idade de 63 anos. Em 3.887 casos (66%) o residente estava envolvido na operação. O grupo Residente apresentou tempo operatório mediano significantemente maior que o grupo Não Residente (163 ± 64 min vs. 138 ± 58 min, p < 0.0001). Todas as outras variáveis estudadas não diferiram significativamente entre os grupos. Além disso, a análise multivariada não demonstrou nenhuma associação entre o envolvimento do residente na operação e a ocorrência de complicações pós-operatórias. CONCLUSÃO: O treinamento laparoscópico durante a residência pode ser realizado com segurança sem colocar em risco a integridade do paciente operado.OBJECTIVE: Laparoscopic approach should be offered for most patients requiring colectomy, as it is a safe procedure, associated with shorter hospitalization, better cosmetic results, and does not affect negatively the oncological outcomes of patients with colon cancer. However, there is no consistent data on the safety of laparoscopic surgery training during residency. Therefore, the aim of this study was to assess whether or not the resident participation in laparoscopic colectomy affected the postoperative outcomes. METHODS: The database of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) was searched for patients undergoing laparoscopic colectomies between 2005 and 2007. We excluded patients with no data regarding whether or not there was a resident participation in the operation. The study population was divided into 2 groups (resident and nonresident), according to residents participation in the surgical procedure. Perioperative variables and postoperative complications were compared between groups. A multivariate analysis was performed to evaluate the association between postoperative complications and resident participation in the operation. RESULTS: The search yielded 5,912 patients with a median age of 63 years. Of these, 3,112 (53%) were female and 3.887 (66%) had a resident involved in their operation. The resident group had a significantly longer mean operative time (163 ± 64 min vs 138 ± 58 min, p < 0.0001). Other variables did not differ significantly between groups. Moreover, multivariate analysis showed no association between resident participation and the occurrence of postoperative complications. CONCLUSION: Laparoscopic training during residency may be safely performed without threatening the patient's integrity

The effect of carbon dioxide pneumoperitoneum on the healing colonic anastomosis in rats

PURPOSE: To investigate the effects of pneumoperitoneum on colonic anastomosis healing. METHODS: Colonic anastomosis was performed in 120 rats divided into four groups: Group I - pneumoperitoneum before laparotomy, Group II - pneumoperitoneum after laparorrhaphy, Group III - pneumoperitoneum before laparotomy and after laparorrhaphy, Group IV - no pneumoperitoneum (control group). Pneumoperitoneum pressure was 5 mmHg. Animals were killed on the 3rd, 7th and 14th postoperative day. Hhistopathological features, anastomosis breaking strength, collagen histomorphometry and hydroxyproline concentration were assessed. RESULTS: Breaking strength between groups: (day 3, p=0.165; day 7, p=0.219; day 14, p=0.539). Histopathology revealed that group II had, on day 7, less infiltration of mononuclear cells (p=0.006), greater infiltration of polymorphonuclear cells (p=0.001) and greater necrosis (p=0.001); and on day 14, less fibrosis. Histomorphometry revealed a decrease in collagen in groups I and III (p<0.001) on day 7 and an increase in groups I and II on day 14 (p<0.001). Hydroxyproline concentration was similar for groups on days 3 (p=0.152), 7 (p=0.913) or 14 (p=0.981). CONCLUSION: Carbon dioxide does not impair the healing of colonic anastomosis in rats