Scielo RSS <![CDATA[Acta Cirurgica Brasileira]]> vol. 30 num. 1 lang. en <![CDATA[SciELO Logo]]> <![CDATA[Hemodynamic, ventilatory and gasometric evaluation of an experimental bronchopleural fistula]]> PURPOSE: To investigate the hemodynamic and ventilatory changes associated with the creation of an experimental bronchopleural fistula (BPF) treated by mechanical ventilation and thoracic drainage with or without a water seal. METHODS : Six large white pigs weighing 25 kg each which, after general anesthesia, underwent endotracheal intubation (6mm), and mechanically ventilation. Through a left thoracotomy, a resection of the lingula was performed in order to create a BPF with an output exceeding 50% of the inspired volume. The chest cavity was closed and drained into the water sealed system for initial observation of the high output BPF. RESULTS: Significant reduction in BPF output and PaCO2 was related after insertion of a water-sealed thoracic drain, p&lt; 0.05. CONCLUSION: Insertion of a water-sealed thoracic drain resulted in reduction in bronchopleural fistula output and better CO2 clearance without any drop in cardiac output or significant changes in mean arterial pressure. <![CDATA[Development of a subcutaneous endometriosis rat model]]> PURPOSE: To present a rat model of subcutaneous endometriosis for the study of pathophysiology and the effects of drugs. METHODS: Fifty three-month-old female Wistar rats (Rattus norvergicus) were distributed into one control group and four treatment groups: estradiol (2.5; 5; 10mg/kg sc), medroxyprogesterone acetate (0.5; 2; 5mg/kg sc), triptorelin pamoate (0.18; 0.56mg/kg sc) and acetylsalicylic acid (3mg/kg per os). The animals were autoimplanted subcutaneously with 4x4-mm uterine fragments to induce endometriosis. The endometriomas were measured on days 1, 7, 14 and 21. The relative dry and wet weights of the endometrioma were used to evaluate response to the drug. Endometrial -like tissue was confirmed by histology. The greatest weight gain was observed on day 14 (relative wet weight: 29.1 ± 6.7mg%, relative dry weight: 5.3 ± 0.9mg %). Treatments were administered between day 5 and day 14. RESULTS: The relative wet weight of the hemiuterus in the 10mg/kg estradiol group differed significantly from control and the other two estradiol groups (p=0.0001). In the medroxyprogesterone acetate group the weight decreased significantly but this decrease was not dose-dependent. Weight reduction was also significant in the triptorelin pamoate and the acetylsalicylic acid groups. CONCLUSION: The model of subcutaneous endometriosis is reproducible, low-cost and easy to perform, and suitable for the study of pathophysiology and the effects of drugs. <![CDATA[Laceration in rat gastrocnemius. Following-up muscle repairing by ultrasound biomicroscopy (in vivo), contractility test (ex vivo) and histopathology]]> PURPOSE: Implement a laceration protocol of the rat lateral gastrocnemius (LG) and following-up its repair with ultrasound biomicroscopy (UBM), contractility tests and histology. METHODS: Sixty-three male Wistar rats were distributed into two groups. One, with sub-groups GI, GII and GIII (n=12), each containing right LG lacerated (n=6), control and sham (n=3) animals. LG muscles in GI, GII and GIII were inspected by UBM (40 MHz) immediately after, 14 and 28 days post-surgery and thereafter excised with four (GI), 14 (GII) and 28 (GIII) days post-surgery for histology. Animals in second group were distributed into right LG lacerated and control sub-groups. LG muscles in lacerated sub-group were submitted to contractility tests at four (n=8), 14 (n=8) and 28 (n=8) days post-surgery, while in the control sub-group (n=5) were submitted to contractility tests along the course of the experiments. RESULTS: Descriptive findings agreed between the lesion model, muscle repair, UBM images and histology. Contractility results for right LG were different (p&lt;0.05) between control and injured muscle with four and 14 days post-surgery, at tetanic stimulating frequencies (50 and 70 Hz). CONCLUSION: A laceration protocol of the lateral gastrocnemius was implemented and ultrasound biomicroscopy, contractility and histology findings agreed regarding the following-up of injured muscle repair. <![CDATA[Effect of propranolol on capsular reaction around silicone implants in guinea pigs]]> PURPOSE: To evaluate the effect of propranolol on capsular architecture around silicone implants by measuring the inflammation, capsular thickness, and collagen fiber density, using a guinea pig experimental model. METHODS: Thirty six adult male guinea pigs randomly divided into two groups (n=18) were used. Each one received a silicone implant with textured-surface. The capsular tissue around implants from untreated or treated animals with the beta-adrenoceptor antagonist propranolol (10 mg/kg, dissolved in daily water) were analyzed for inflammation by histological scoring, capsular thickness by computerized histometry, and collagen fibers type I and Type III density by picrosirius polarization at different time points (7, 14 or 21 days after silicone implantation). RESULTS: Propranolol treatment reduced inflammation and impaired capsular thickness and delayed collagen maturation around the textured implant. CONCLUSION: Propranolol reduces the risk of developing capsular contracture around silicone implants with textured surface. <![CDATA[An evaluation of the protective effect of an infusion of chilled glucose solution on thermal injury of the bile ducts caused by radiofrequency ablation of the liver]]> PURPOSE: To evaluate the protective effects of chilling the bile ducts with cold (5°C) 5% glucose solution (GS) during radiofrequency (RF) administration. METHODS: Twenty male pigs (3 mos. old; 25-30 kg) were subjected to RF delivery with chilling (experimental group, N=10) or without chilling (control group, N=10). Half of the animals in each group were euthanized immediately after the operation, and half were euthanized one week later. The following histological variables in relation to the bile ducts were evaluated by a pathologist (blind examiner): degenerative changes to the epithelium; epithelial necrosis; ulceration, regenerative changes of the epithelium; polymorphonuclear neutrophil infiltration; and thermal effects. RESULTS: The experimental group (88 bile ducts examined) showed reduced thermal damage relative to the control group (86 bile ducts examined) as demonstrated by significant differences in the following histopathological parameters: epithelial detachment of biliary epithelium (84.1% vs. 59.3%; p&lt;0.006); elongation/palisade arrangement of nuclei (65.1% vs. 87.5%; p&lt;0.001); pseudo-goblet cells (32.9% vs. 56.8%; p&lt;0.001). CONCLUSION: Infusion of 5% glucose solution (5°C) has a protective effect on bile ducts subjected to heat (95-110°C, 12 min) from radiofrequency thermal ablation device. <![CDATA[Combined polyglycolic acid tube and autografting versus autografting or polyglycolic acid tube alone. A comparative study of peripheral nerve regeneration in rats]]> PURPOSE: To compare sciatic nerve regeneration in rats using three different techniques of repair. METHODS: Fifteen isogonics rats were divided into three groups according to the method used to repair a 5-mm long defect created in the sciatic nerve: autogenous graft (Group A), polyglycolic acid tube (PGAt) (Group B), and of the association of PGAt with the graft (Group C). Histological analysis, regenerated myelinated axon number count and functional analysis were used to compare after six weeks. RESULTS: There was no difference in fiber diameter and degree of myelinization presented by Groups A, B and C. Group B presented the lowest number of regenerated axons. The groups did not display any significant functional difference after walking track analysis (p&lt;0.05). CONCLUSION: No differences between the three groups in terms of functional recovery, although there were histological differences among them. <![CDATA[Effect of cyclosporine on liver regeneration in partial hepatectomized rats]]> PURPOSE: To evaluate the influence of the cyclosporine in liver regeneration in rats submitted to an experimental model of 70% hepatectomy. METHODS: Forty male rats were randomly divided in four subgroups (C.24h, C.7d, E.24h, E.7d), according to the drug used and the day of sacrifice (24 hours and 7 days). Cyclosporine (10mg/Kg/day) was given to the study subgroup and 1 ml of 0.9% sodium chloride was to the control subgroup. Resection of left lateral lobe and median lobe performing 70% of liver mass. During the animals' death, KWON formula was applied. Counting of mitotic figures and percentage of positive nucleus with PCNA and Ki-67 were evaluated. RESULTS: In the 2nd, 4th PO and death days, E.7d lose more weight than C.7d. Regarding to the KWON formula, the C.7d regenerated more than the C.24h and the same with the E.7d. Comparing between the groups, only E7d subgroup was statistically significant compared with C.7d, showing the stimulating effect of cyclosporine in liver regeneration. Immunohistochemestry had significant results between the study subgroups. The mitotic index revealed statistical differences in the control subgroups. CONCLUSION: Cyclosporine, in spite of being an immunosuppressive drug, has a positive effect in liver regeneration, although reduce the animal's body weight. <![CDATA[Ozone oxidative preconditioning protects the rat kidney from reperfusion injury via modulation of the TLR4-NF-κB pathway]]> PURPOSE: To investigate the protective effects of ozone oxidative preconditioning (OzoneOP) were associated with the modulation of TLR4-NF-κB pathway. METHODS: Thirty six rats were subjected to 45 min of renal ischemia, with or without treatment with OzoneOP (1 mg/kg). Blood samples were collected for the detection of blood urea nitrogen and creatinine levels. Histologic examinations were evaluated and immunohistochemistry was also performed for localization of TLR4 and NF-κB. The expression of TNF-α, IL-1β, IL-6, ICAM-1 and MCP-1 were studied by Real-time PCR. Western blot was performed to detect the expression of TLR4 and NF-κB. RESULTS: The results indicated that blood urea nitrogen and creatinine levels increased significantly in I/R group. Rats treated with OzoneOP showed obviously less renal damage. Immunohistochemistry showed that TLR4 were ameliorated by OzoneOP. Realtime PCR showed that OzoneOP could significantly inhibit the increased mRNA levels of TNF-α, IL-1β, IL-6, ICAM-1 and MCP-1 induced by I/R. Western blot indicated that the expression of TLR4 and NF-κB were upregulated in I/R group, but OzoneOP could inhibit this increase. CONCLUSION: These findings indicated that OzoneOP had potent anti-inflammatory properties by the modulation of the TLR4-NF-κB pathway in renal ischemia/reperfusion injury. <![CDATA[Bispectral index in calves anesthetized with xylazine, midazolam, ketamine, isoflurane and subjected to continuous rate infusion of lidocaine]]> PURPOSE: To assess the bispectral index (BIS) and recovery in calves anesthetized with xylazine, midazolam, ketamine and isoflurane and subjected to CRI of lidocaine. METHODS: Xilazine was administered followed by ketamine and midazolam, orotracheal intubation and maintenance on isoflurane using mechanical ventilation. Lidocaine (2 mg kg-1 bolus) or saline (0.9%) was administered IV followed by a CRI (100 µg kg-1 minute-1) of lidocaine (L) or saline (C). Were recorded BIS, heart rate (HR), mean arterial pressure (MAP) and rectal temperature (RT) before administration of premedication (TB) and 15 minutes after (TX), before administering lidocaine (T0) and 20, 40, 60 and 80 minutes after the start of the CRI . Time do sternal recumbency (SRE) and standing (ST) and plasma lidocaine concentration also evaluated. RESULTS: In both treatments BIS decreased significantly at all times compared to TB. TX was higher than the subsequent times. HR decreased from baseline at all times and decreased from T40 in L compared to C. SRE was higher in L compared to C. CONCLUSIONS: Bispectral index values were consistent with the degree of hypnosis of the animals. Lidocaine did not potentiate isoflurane anesthesia assessed by BIS in unstimulated calves anesthetized with constant E´Iso. Lidocaine increased the time to sternal recumbency. <![CDATA[Effect of glutamine supplementation on left colon healing in rats with extrahepatic biliary obstruction]]> PURPOSE: To evaluate the influence of glutamine and obstructive jaundice on left colon healing in rats. METHODS: Sixteen male rats were allocated across four groups: LG - Common bile duct ligation followed by colotomy and bowel suture on postoperative day 7. Supplementation with glutamine 2% from day 4 after duct ligation until euthanasia. L - Common bile duct ligation followed by colotomy and bowel suture on postoperative day 7. No glutamine supplementation. M - Common bile duct manipulation followed by colotomy and bowel suture on postoperative day 7. No glutamine supplementation. MG - Common bile duct manipulation followed by colotomy and bowel suture on postoperative day 7. Supplementation with glutamine 2% from day 4 after duct manipulation until euthanasia. On the day of euthanasia, bursting pressure of the sutured bowel segment was measured and samples were collected for histopathological analysis. RESULTS: There were no differences in bursting pressure among groups : LG vs. M (110 ± 28 vs. 173 ± 12; p = 0.08). Groups L and MG were not different from group M (156 ± 12 and 118 ± 22. Glutamine supplementation was associated with less edema, polymorphonuclear lymphocyte infiltration, bacterial colonies, and abscess formation, as well as with increased collagen formation. CONCLUSION: Obstructive jaundice had no negative effect and glutamine supplementation had no positive effect on colonic scar strength in rats. <![CDATA[The investigation of airway management capacity of v-gel and cobra-PLA in anaesthetised rabbits]]> PURPOSE: To evaluate the applicability and airway management capacity of v-gel(r) and Cobra PLA in rabbit anaesthesia during assisted (AV) or controlled ventilation (CV). METHODS: This study was carried out in 44 adult New Zealand white rabbit. Baseline arterial pH, PaCO2 and PaO2 values were recorded. Anaesthesia was induced with 5 mg/kg xylasine and 35 mg/kg ketamine HCI combination. AV rabbits were assigned as; control (CG-AV; n=5), LMA (LMA-AV; n=5), cobra PLA (PLA-AV; n=5) and v-gel (v-gelAV; n=5). Rabbits have CV were also assigned as; ET (ET-CV; n=6), LMA (LMA-CV; n=6), cobraPLA (PLA-CV; n=6) and v-gel (v-gelCV; n=6). All measurements were repeated 1st, 5th, 15th and 30th mins during anaesthesia. RESULTS: The less insertion time, number of attempt and complications are recorded in v-gel applied rabbits compared to other apparatus. For arterial pH values significant differences are recorded in especially at 15th and 30th min between groups of CV (p&lt;0.005 or p&lt;0.001). All groups had similar results with each other during anaesthesia for PaCO2 except for LMA-CV group. CONCLUSION: The v-gel may be used as airway device in rabbit anaesthesia undergoing AV or CV and also can be a suitable alternative to endotracheal tubes and laryngeal mask airway.