Abstract Purpose To determine by histomorphometric analysis whether CO2 pneumoperitoneum interferes with collagen deposition in surgical wounds in the aponeurosis of rats. Methods This experiment involved 80 male Wistar rats, randomly allocated into four groups according to pneumoperitoneum period (PRE: 30 min preoperatively; POST: 30 min postoperatively; PP: 30 min pre- and postoperatively; C: control group). CO2 pneumoperitoneum was insufflated to 5 mmHg of pressure. A laparotomy was performed; 1 cm of the left colon was then resected, and an end-to-end anastomosis was performed to simulate surgical trauma, after which the abdominal wall was closed. On postoperative days 7 or 14, a sample of the abdominal wall was collected, stained with picrosirius red and observed under polarized light in an optical microscope. The amount of collagen was estimated by computerized histomorphometric analysis. Results There were no significant differences in collagen deposition between the control and experimental groups on postoperative days 7 (p=0.720) or 14 (p=0.933). The amount of collagen increased as expected in all groups between postoperative days 7 and 14 (p=0.0003). Conclusion At 5 mmHg, CO2 pneumoperitoneum does not interfere with collagen deposition in abdominal wall surgical wounds in rats.

PURPOSE: To evaluate the effects of acute alcohol intoxication on healing of colonic anastomosis. METHODS: Thirty-six rats were allocated into two groups. Animals in the alcohol (A) were given 2 mL of ethanol diluted in 0.9% saline solution to a concentration of 40% by gavage immediately before anesthesia, whereas control (C) animals received 2 mL of 0.9% saline solution via the same route. A colonic anastomosis was then performed in all animals. On postoperative days 1, 3, and 7, anastomotic breaking strength was assessed and histopathological examination was performed. Change in body weight and mortality were also evaluated. RESULTS: The median of anastomotic tensile strength on the postoperative day 1 was 0.09 Newtons for group A and 0.13 for group C. (p>0.05). The median of anastomotic tensile strength on the postoperative day 3 was 0.13 Newtons for group A and 0.17 for group C. (p>0.05). The median of anastomotic tensile strength on the postoperative day 7 was 0.30 Newtons for group A and 0.35 for group C. (p>0.05). There was no significant difference between the groups A and C, in the first, third or seventh POD (p>0.05), in any of the analyzed parameters. There were no statistical differences between groups in the weight. Three animals died, all from the group A. CONCLUSION: Acute alcohol intoxication did not interfere with wound healing of colonic anastomoses, although it caused early postoperative mortality.

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.

OBJETIVO: Avaliar a influência do pneumoperitônio com dióxido de carbono na cicatrização da ferida operatória na parede abdominal de ratos. MÉTODOS: Oitenta ratos foram submetidos à laparotomia, ressecção de segmento do cólon esquerdo e anastomose. Os animais foram distribuídos em quatro grupos de 20 ratos, três experimentais e um controle: Grupo EI = pneumoperitônio por 30 minutos antes da laparotomia. Grupo EII = pneumoperitônio por 30 minutos após a laparorrafia. Grupo EIII = pneumoperitônio por 30 minutos antes da laparotomia e 30 após a laparorrafia. Grupo C = controle, sem pneumoperitônio. Realizou-se, em cada grupo, a eutanásia de 10 animais no 7° e no 14° dia pós-operatório. Um segmento da parede abdominal foi ressecado e submetido à medida da resistência. Outro segmento muscular abdominal foi destinado à análise histopatológica, as peças foram fixadas em formol e as lâminas coradas com hematoxilina e eosina. RESULTADOS: Não houve diferença, à histopatologia e na força de ruptura, entre os animais dos grupos experimentais e do controle no 7° ou 14° dia pós-operatório. CONCLUSÃO: Nas condições em que o experimento foi realizado, o pneumoperitônio com dióxido de carbono não interferiu na cicatrização da parede abdominal.

PURPOSE: To evaluate the influence of carbon dioxide pneumoperitoneum on abdominal wall wound healing in rats. METHODS: Eighty rats underwent laparotomy, segmental left colon resection, and anastomosis. The animals were divided into three experimental groups and one control group: EI = pneumoperitoneum for 30 minutes before laparotomy (n=20); EII = pneumoperitoneum for 30 minutes after abdominal closure (n=20); EIII = pneumoperitoneum for 30 minutes before laparotomy and 30 minutes after abdominal closure (n=20); C = control group, without pneumoperitoneum (n=20). In each group, 10 animals were killed 7 days and 10 animals 14 days postoperatively. A segment of the abdominal wall was resected and subjected to tensile strength testing. Another segment of abdominal muscle was used for histopathological analysis; the specimens were fixed in formalin and stained with hematoxylin and eosin. RESULTS: There were no differences in histopathology and tensile strength values among animals in the experimental and control groups 7 or 14 days after surgery. CONCLUSION: Under the present experimental conditions, carbon dioxide pneumoperitoneum did not interfere with abdominal wall wound healing.

OBJETIVO: Avaliar os efeitos do aumento de pressão intraperitonial causada pelo pneumoperitônio com dióxido de carbono na morfologia renal e hepática de ratos submetidos à colectomia segmentar a anastomose colônica. MÉTODOS: 54 ratos machos da linhagem Winstar, que, após serem anestesiados, foram aleatoriamente distribuídos em três grupos (P, PP e C): P - 18 animais submetidos a pneumoperitônio por 30 minutos imediatamente antes da laparotomia PP - 18 animais submetidos a pneumoperitônio por 60 minutos, 30 imediatamente antes da laparotomia e 30 após a laparorrafia ; C - (grupo controle) - 18 animais submetidos à laparotomia sem o uso de pneumoperitônio. Os animais foram mortos no terceiro e sétimo dia pós-operatório, quando ocorreu a coleta do rim e parte do fígado. As peças foram coradas com Hematoxilina e Eosina e Von Kossa e analisadas por um patologista que desconhecia os grupos. RESULTADOS: Não foram observadas alterações nas estruturas renais. Nas amostras hepáticas foram observados achados histológicos como a degeneração hidrópica no grupo de animais mortos no sétimo DPO (p= 0,029). CONCLUSÃO: O pneumoperitônio com dióxido de carbono não afetou a morfologia renal e causou a degeneração hidrópica no fígado dos animais mortos no 7º dia pós-operatório.

PURPOSE: To evaluate the effects of increased intraperitoneal pressure caused by carbon dioxide pneumoperitoneum on the hepatic and renal morphology of rats. METHODS: Fifty-four adult male rats were randomly divided into three groups (P, PP and C) after anesthesia: P - in 18 animals, pneumoperitoneum was established for 30 minutes immediately before laparotomy; PP - in 18 animals, pneumoperitoneum was established for 60 minutes divided into 30 immediately before laparotomy and 30 after abdominal closure; control group (C) - 18 animals underwent laparotomy without pneumoperitoneum induction. The pneumoperitoneum was maintained at a pressure of 5 mm Hg. Nine animals in each group were killed on the 3rd and 7th postoperative days, when kidney and liver samples were collected for morphological analysis. The liver specimens were stained with hematoxylin and eosin (HE), and the kidney specimens, with HE and von Kossa. Blinded examiners analyzed the slides. RESULTS: No changes in renal morphology were found. Liver samples showed histological signs of degeneration in animals in the pneumoperitoneum groups killed on the 7th postoperative day (p=0.029). CONCLUSION: The CO2 pneumoperitoneum did not affect renal morphology but caused hydropic degeneration in the liver of animals killed on the 7th postoperative day.