Paulo Gonçalves de Oliveira

Influence of misoprostol, a synthetic prostaglandin E1 analog, on the healing of colonic anastomoses in rats

PURPOSE: This study was designed to examine the influence of misoprostol, a synthetic prostaglandin E1analog, on the healing of colonic anastomoses in rats, with particular regard to changes in collagen levels at the site of the anastomoses and their histopathologic aspects. METHODS: Sixty rats were submitted to resection and anastomosis of the colon, and divided at random into two groups. The test group received misoprostol intragastrically (200 μg/kg body weight), twice daily, from the day of operation until sacrifice. Controls received 0.9 percent NaCl. The animals were sacrificed on the third, seventh, or fourteenth postoperative day, and the results of the histopathologic analyses and hydroxyproline concentrations were compared. RESULTS: Our results show that misoprostol administration increased the hydroxyproline concentration on the fourteenth postoperative day without interfering in the inflammatory response (P<0.05).CONCLUSION: Misoprostol interferes with the balance between the synthesis and degradation of collagen, resulting in an elevation of collagen levels by the fourteenth postoperative day without influencing the inflammatory response.

Analysis of the tensile strength on the healing of the abdominal wall of rats treated with infliximab

PURPOSE To evaluate the effects of infliximab, a murine/human chimeric monoclonal antibody, on the tensile strength of abdominal wall surgical wounds. METHODS Sixty Wistar healthy male rats with initial body weight between 215 and 390 g and 60 and 90 days of age were randomly assigned into two groups, E (Experimental) and C (Control) with 30 animals each. Group E animals received a single subcutaneous dose of 5mg/Kg of infliximab, and Group C animals received equivalent subcutaneous volume of a solution of 0.9% NaCl. After 48h, animals from both groups were submitted to a 4 cm median incision in the abdominal wall, including all layers that had been reconstituted with continuous suture of the aponeurotic muscle and skin, with 5.0 nylon thread. Then, Group E animals were separated by simple allotment into three subgroups named E3, E7 and E14 with ten animals each, and those from group C into C3, C7, C14 and were submitted, respectively, the reoperation and euthanasia at the third, seventh and fourteenth postoperative day. The anterior abdominal wall, which was resected during reoperation, was cut with No 15 scalpel lamina perpendicularly to the surgical wound. Each specimen, in the form of a 6 cm x 2 cm strip, was fixed by the extremity so that the suture line was equidistant from the fixation points of the dynamometer, in order to undergo the tensile strength test. The dynamometer, which was gauged for each series of measures, was calibrated to apply velocity to the 25 mm/min rupture test; the rupture value was expressed in N (Newton). Prior to euthanasia, the abdominal vena cava was identified and punctured in order to collect blood for TNF-alpha dosage. RESULTS The mean tensile strength found for animals from subgroups E3, E7, E14, C3, C7, C14 were, respectively, 16.03, 18.69, 27.01, 28.40, 27.22, 29.15 and 24.30 N. In the results of the multiple comparisons tests, significant differences (p<0.05) was found between subgroups E3 and E7 compared with C3, C7 and C14. CONCLUSION The infliximab interfered in the healing of the abdominal wall wound decreasing the rupture strength in the inflammatory and proliferative phases.

Uncovering the neuroenteric–pulmonary axis: Vagal nerve stimulation prevents acute lung injury following hemorrhagic shock

AIMS Trauma/hemorrhagic shock (T/HS) induced gut injury is known to initiate a systemic inflammatory response which can lead to secondary lung injury. We have shown that vagal nerve stimulation (VNS) protects intestinal epithelial integrity after a severe burn insult. We hypothesize that VNS will protect the lung from injury following T/HS by preventing intestinal barrier failure. MAIN METHODS Male Balb/c mice were subjected to a T/HS model with and without cervical VNS. Intestinal injury was evaluated by measuring changes in gut barrier function and tight junction protein localization. Lung injury was evaluated using histology and markers of lung inflammation. Using NF-kB-luciferase (NF-kB-luc) transgenic mice, NF-kb-DNA binding was measured by photon emission analysis at 4 after injury. KEY FINDINGS T/HS is associated gut injury characterized by histologic injury, increased epithelial permeability, and altered localization of gut tight junction proteins. Cervical VNS prevented the T/HS-induced changes in gut barrier integrity. Gut injury after T/HS was associated with acute lung injury at 24 h characterized by histologic injury, increased number of MPO positive stained cells and MPO enzymatic activity, and increased ICAM-1 expression in lung endothelium. VNS decreased T/HS-induced lung injury with a marked decrease in lung inflammation compared to T/HS alone. Lungs harvested from NF-kB-luc mice at 4h post VNS+T/HS demonstrated decreased DNA binding of NF-kB compared to T/HS alone as measured by changes in bioluminescence. SIGNIFICANCE VNS is effective in protecting against acute lung injury caused by hemorrhagic shock through its ability to prevent gut barrier dysfunction.

Does metoclopramide impair anastomotic healing of the left colon of rats

PURPOSE To evaluate the effects of metoclopramide on the formation of adhesion and the healing of left colonic anastomoses in rats. METHODS Forty rats underwent sectioning of the left colon and end-to-end anastomosis and were divided into two groups of 20 animals for the administration of metoclopramide (experimental group - E) or saline solution (control group - C). Each group was divided into subgroups of 10 animals each to be killed on the third (E3 and C3) or seventh postoperative day (E7 and C7). Adhesion was assessed, and a colonic segment containing the anastomosis was removed for analysis of breaking strength and hydroxyproline concentration. RESULTS There were no deaths or dehiscence on the 3(rd) postoperative day. There was one death and one blocked anastomotic dehiscence in the E7 group. No significant differences between groups were found in the analysis of clinical outcome, intra-cavity adhesion, adhesion to the anastomosis or breaking strength on the 3(rd) and 7(th) postoperative day. Hydroxyproline concentration was higher in the control group on the 3(rd) (p=0.006) but not on the 7(th) postoperative day (p=0.241). CONCLUSION Metoclopramide did not have harmful effects on the healing of intestinal anastomoses in rats.

Effects of carbon dioxide pneumoperitoneum on hepatic and renal morphology of rats after segmental colectomy and colonic anastomosis

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 3(rd) and 7(th) 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 7(th) postoperative day (p=0.029). CONCLUSION The CO(2) pneumoperitoneum did not affect renal morphology but caused hydropic degeneration in the liver of animals killed on the 7(th) postoperative day.

Improving Organ Salvage in Testicular Torsion: Comparative Study of Patients Undergoing vs Not Undergoing Preoperative Manual Detorsion

Purpose: We compared surgical outcomes between patients undergoing and those not undergoing preoperative manual detorsion for intravaginal testicular torsion. Materials and Methods: We retrospectively analyzed consecutive patients treated surgically for testicular torsion who were examined within 24 hours of symptoms at our emergency department between January 2012 and September 2015. Explanatory variables were age, presentation delay (time between symptoms and urological examination), surgical wait time (time from examination to surgery), and whether manual detorsion was attempted and, if attempted, was declared successful. End points were surgical outcome (orchiopexy, orchiectomy) and testicular rotation at surgery. Statistical analysis included nonparametric tests and logistic regression. Statistical significance and confidence intervals were set at p <0.05 and 0.95, respectively. Results: Detorsion was attempted in 76 of 133 cases (57.1%) and was successful in 72 (95.1%). Patient age (median 15.6 vs 17.4 years, p = 0.115), presentation delay (6.6 vs 6.3 hours, p = 1.0) and surgical wait time (3.5 vs 3.2 hours, p = 0.412) were comparable between patients who underwent manual detorsion attempt and those who did not. Testicular rotation was less among successfully detorsed patients. Orchiectomy was performed in 2 of 72 successfully detorsed patients (2.8%), compared to 15 of 61 patients (24.6%) in whom detorsion was not attempted or was unsuccessful (OR 11.23, p = 0.0002). Logistic regression indicated that surgical wait time (OR 0.95, p = 0.002) and successful detorsion (OR 17.38, p = 0.001) were independently associated with orchiopexy. Conclusions: Preoperative manual detorsion was associated with improved surgical salvage in patients with testicular torsion.

Influence of patient age and colorectal polyp size on histopathology findings

Background Colorectal cancer is a major cause of morbidity and mortality and can arise through the adenoma-carcinoma sequence. Colonoscopy is considered the method of choice for population-wide cancer screening. Aim To assess the characteristics of endoscopically resected polyps in a consecutive series of patients who underwent colonoscopy at a university hospital and compare histopathology findings according to patient age and polyp size. Methods Retrospective, cross-sectional of 1950 colonoscopy reports from consecutively examined patients. The sample was restricted to reports that mentioned colorectal polyps. A chart review was carried out for collection of demographic data and histopathology results. Data were compared for polyps sized ≤0.5 cm and ≥0.6 cm and then for polyps sized ≤1.0 cm and ≥1.1 cm. Finally, all polyps resected from patients aged 49 years or younger were compared with those resected from patients aged 50 years or older. Results A total of 272 colorectal polyps were resected in 224 of the 1950 colonoscopies included in the sample (11.5%). Polyps >1 cm tended to be pedunculated (p=0.000) and were more likely to exhibit an adenomatous component (p=0.001), a villous component (p=0.000), and dysplasia (p=0.003). These findings held true when the size cutoff was set at 0.5 cm. Patients aged 50 years or older were more likely to have sessile polyps (p=0.023) and polyps located in the proximal colon (p=0.009). There were no significant differences between groups in histopathology or presence of dysplasia. Conclusion Polyp size is associated with presence of adenomas, a villous component, and dysplasia, whereas patient age is more frequently associated with sessile polyps in the proximal colon.

Partners of patients having a permanent colostomy should also receive attention from the healthcare team.

This study was carried out to determine how the partners of patients with a permanent colostomy perceive everyday life, particularly its sexual aspects.

Correlation between bursting pressure and breaking strength in colonic anastomosis

PURPOSE To investigate the correlation between bursting pressure and breaking strength on the 7th postoperative day following left colonic anastomosis in rats. METHODS Seventy rats were randomly divided into seven groups of ten animals each. All of the animals underwent segmental resection of the left colon and end-to-end anastomosis. The animals in groups I to VI underwent surgical laparoscopies with pneumoperitoneums using carbon dioxide or helium at pressures of 5, 12 or 20 mmHg. In Group VII, open laparotomy was performed. The animals were reoperated on postoperative day 7 to measure the bursting pressure and the breaking strength of the anastomosis. RESULTS The anastomosis bursting pressure in 70 animals was 193.10±55.56 mmHg. There was no significant difference between the groups (p=0.786). The breaking strength of the anastomosis was 0.26±0.12 N. There was no significant difference between the groups (p=0.356). Pearsons correlation test showed a low correlation (r=0.231) lacking statistical significance (p=0.054). CONCLUSION There was no correlation between the bursting pressure and breaking strength of left colonic anastomoses in rats on the 7th postoperative day.

Effects of bromopride on the healing of left colonic anastomoses in rats with induced abdominal sepsis

PURPOSE To evaluate the effects of bromopride on the healing of left colonic anastomoses in rats with induced abdominal sepsis. METHODS Forty rats were divided into two groups to receive either bromopride (experimental group- E) or saline (control group- C). Each group was divided into subgroups of ten animals each to be euthanized on third (E3 and C3) or seventh day (E7 and C7) after surgery. Sepsis was induced by cecal ligation and puncture. The rats underwent segmental left colon resection and end-to-end anastomosis. Adhesion formation, tensile strength and hydroxyproline concentration were assessed. Histomorphometry of collagen and histopathological analysis were also performed. RESULTS On postoperative third day, anastomoses in bromopride-treated animals showed lower tensile strength (p=0.02) and greater reduction in hydroxyproline concentration (p=0.04) than in control animals. There was no statistical difference in these parameters on seventh day, and the remaining parameters were similar across subgroups. Collagen content was also similar across subgroups. CONCLUSION In the presence of abdominal sepsis, the administration of bromopride was associated with decreased tensile strength and hydroxyproline concentration in left colonic anastomoses in rats three days after surgery.