Effect of preconditioning and postoperative hyperbaric oxygen therapy on colonic anastomosis healing with and without ischemia in rats.

PURPOSE: To investigate the effect of hyperbaric oxygen therapy on colonic anastomosis healing with and without ischemia in rats. METHODS: Forty female rats underwent segmental resection of 1 cm of the left colon followed by end-to-end anastomosis. They were randomly assigned to four groups (n=10 each), a sham group; two groups were submitted to Hyperbaric Oxygen therapy (HBOT) with and without induced ischemia and the induced ischemia group without HBOT. The HBOT protocol evaluated was 100% O2 at 2.4 Atmosphere absolute pressure (ATA) for 60 minutes, two sessions before as a preconditioning protocol and three sessions after the operation. Clinical course and mortality were monitored during all experiment and on the day of euthanasia on the fourth day after laparotomy. Macroscopic appearance of the abdominal cavity were assessed and samples for breaking strength of the anastomosis and histopathological parameters were collected. RESULTS: There was no statistically significant difference in mortality or anastomosis leak between the four experimental groups. Anastomosis breaking strength was similar across groups. CONCLUSION: The HBOT protocol tested herein at 2.4 ATA did not affect histopathological and biomechanical parameters of colonic anastomotic healing, neither the clinical outcomes death and anastomosis leak on the fourth day after laparotomy.

Does CO2 pneumoperitoneum in laparoscopy interfere with collagen deposition in abdominal surgical wounds?

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.

Interference of ethanol and methylmercury in the developing central nervous system.

Studies involving alcohol and its interactions with other neurotoxicants represent the focus of several works of research due to the fact that the use of alcohol can sometimes leads to serious health problems. Fetal exposure to alcohol and mercury has a high incidence in some regions of Brazil, where there are pregnant women who are alcoholics and live in mining areas. This work was conducted to examine the effects of combined exposure to ethanol (EtOH) and methylmercury (MeHg) in rats during the development of the central nervous system (CNS). Experimental behavioral animal models/tests were used in order to examine locomotion, anxiety, depression and memory. Pregnant rats received tap water or EtOH 22.5% w/v (6.5 g/kg per day), by gavage) during pregnancy and breast-feeding. On the 15th day of pregnancy, some groups received 8 mg/kg of MeHg (by gavage). The groups were as follows: control, EtOH, MeHg and EtOH+MeHg. The experimental results showed that the EtOH, MeHg and EtOH+MeHg groups reduced the percentage of frequency and time spent in the open arms entries of the elevated plus-maze (EPM) test, when compared to the control group. This result suggests an anxiogenic behavioral response. The MeHg group increased locomotor activity in the arena and the immobility time in the forced swimming test, suggestive of depression-like behavior. The EtOH+MeHg group showed greater reductions in the percentages of frequency and time spent in the open arms entries in the EPM test, suggesting a sedative-behavior since the frequency of enclosed arm entries was affected. In the inhibitory avoidance task, the EtOH+MeHg group reduced the latency of the step-down response onto the grid floor, suggesting a cognitive and behavior dysfunctions. Taken together, the results suggest that EtOH and/or MeHg intoxication during the developing CNS may be a risk for deficits related to locomotor impairment, anxiety, depression and neurocognitive functions. There is a possibility that EtOH may prevent some of the MeHg responses, but the precise mechanism of action involved in this process needs to be considered for future research.

Histopathologic evaluation of the peritoneum exposed to heat shock: experimental study in rats.

PURPOSE: To evaluate histopathologic alterations of the peritoneum exposed to heat shock. METHODS: Sixty rats were randomly distributed into 6 groups: Heat Shock (HS), High Temperature (HT), Body Temperature (BT), Temperature 0oC (TZ), Sham (SH) and Control (CG) with 10 animals each. The peritoneal cavity of animals from groups HS, HT, BT and TZ was irrigated with NaCl solution 0.9% at temperatures 50 degrees C, 0 degrees C, 50 degrees C, 37 degrees C and 0 degrees C, respectively. For animals from group SH, the procedures were simulated and those from group CG, laparotomy and biopsies were conducted. Twenty-four hours later, biopsies of the peritoneum for exams under light and electronic microscopy were performed. RESULTS: Edema was found in groups HS 80%, HT 60%, BT 30% TZ 70%, SH 40% and CG 30%. Vascular congestion was found in groups HS 20%, HT 30%, BT 10% and TZ 20%. Erythrocyte extravasation was found in groups HT 60% and SH 10%. Mesothelium destruction was found in 100% of specimens from groups HS, HT, BT, TZ, SH and CG 90%. Necrosis was found in groups HS 30%, HT 20% and BT 10%. The mean peritoneal thickness ranged from 42.26 microm (TZ) to 26.42 microm (CG). CONCLUSION: The heat shock caused no deaths, but promoted significant peritoneal edema without affecting the other histopathologic indicatives.

Improving reproducibility and external validity. The role of standardization and data reporting of laboratory rat husbandry and housing.

PURPOSE:: To identify the most relevant flaws in standardization in husbandry practices and lack of transparency to report them. This review proposes some measures in order to improve transparency, reproducibility and eventually external validity in experimental surgery experiments with rat model. METHODS:: We performed a search of scientific articles in PUBMED data base. The survey was conducted from august 2016 to January 2017. The keywords used were "reproducibility", "external validity", "rat model", "rat husbandry", "rat housing", and the time frame was up to January 2017. Articles discarded were the ones which the abstract or the key words did not imply that the authors would discuss any relationship of husbandry and housing with the reproducibility and transparency of reporting animal experiment. Reviews and papers that discussed specifically reproducibility and data reporting transparency were laboriously explored, including references for other articles that could fulfil the inclusion criteria. A total of 246 articles were initially found but only 44 were selected. RESULTS:: Lack of transparency is the rule and not the exception when reporting results with rat model. This results in poor reproducibility and low external validity with the consequence of considerable loss of time and financial resources. There are still much to be done to improve compliance and adherence of researchers, editors and reviewers to adopt guidelines to mitigate some of the challenges that can impair reproducibility and external validity. CONCLUSIONS:: Authors and reviewers should avoid pitfalls of absent, insufficient or inaccurate description of relevant information the rat model used. This information should be correctly published or reported on another source easily available for readers. Environmental conditions are well known by laboratory animal personnel and are well controlled in housing facilities, but usually neglected in experimental laboratories when the rat model is a novelty for the researcher.

McKittrick-Wheelock syndrome secondary to rectal adenocarcinoma

Introduction: McKittrick-Wheelock syndrome is a rare condition that arises from a hypersecretory state secondary to large colorectal tumors, mainly villous adenomas, leading to an electrolytic disorder associated with chronic diarrhea that usually persists for years. It is a relatively unknown disease that can lead to severe complications such as acute kidney injury, severe hyponatremia, and hypokalemia. In fact, it causes death in most untreated cases. Surgical removal of the tumor is the most successful treatment, and symptoms tend to disappear after proper management. Case Report: A 62-year-old man with a 2-year history of mucoid diarrhea preceded by abdominal pain presented with acute kidney injury, hyponatremia, and hypokalemia. A digital rectal examination and sigmoidoscopy were performed, and revealed a large laterally-spreading tumor in the rectum. Further investigation showed a rectal tubulovillous adenoma with secondary McKittrick-Wheelock syndrome. An anterior resection of the rectum with a colonic J-pouch and a diverting ileostomy were performed, and the patient improved with the resolution of the renal failure and electrolyte disturbances. The histopathological analysis revealed an invasive rectal adenocarcinoma. Discussion: McKittrick-Wheelock syndrome is a condition with a low incidence that needs early intervention and proper diagnosis. It is of extreme importance that this disease is included in the differential diagnoses for chronic diarrhea associated with an electrolytic disorder. (AU)

Effects of enoxaparin on the healing of abdominal wall in rats: study on breaking strength and histopathology.

PURPOSE: To evaluate the influence of enoxaparin on the abdominal wall healing. METHODS: Sixty Wistar male rats were randomly distributed into two experimental groups. Group E: consisted of 30 rats, submitted to abdominal suture and treated with enoxaparin in a dose of 1 mg/kg of body weight, subcutaneously administered from immediate postoperative until the 7th day; Group C: consisted of 30 rats submitted to abdominal suture and treated with the equivalent dose per volume of NaCl 0.9%. The animals were submitted to median laparotomy and were operated again at the 3rd, 7th or 14th postoperative day for the resection of the anterior abdominal wall. The tissue's stretching resistance was tested and a histopathological evaluation was performed. Through Mann-Whitney's U test, a statistical analysis was conducted considering significant values for p <0.05. RESULTS: The tensile breaking strength presented a median of 0.64N for group C and 0.41N for group E (p=0.60) at the 3rd postoperative day; of 2.27N for group C and of 4.32N for group E (p=0.01) at the 7th POD; of 5.72N for group C and of 6.62N for group E (p=0.97) at the 14th POD. In relation to the histopathological study, the results did not show significant statistical differences, except for the amount of collagen at the 7th POD, which medians were 2 on group C and 1 on group E (p=0.007). CONCLUSION: Considering the conditions in which this study was conducted, the administration of enoxaparin led to an strengthening of the tissue's breaking resistance at the 7th POD; on the histopathological exam, a significant difference was observed at the 7th POD, with a better collagen disposition on group C.

Effect of Hevea brasiliensis latex sap gel on healing of acute skin wounds induced on the back of rats.

OBJECTIVE: to evaluate the effect of topical delivery of latex cream-gel in acute cutaneous wounds induced on the back of rats. METHODS: we subjected sixteen rats to dermo-epidermal excision of a round dorsal skin flap, with 2.5cm diameter. We divided the animals into two groups: Latex Group: application of cream-gel-based latex throughout the wound bed on postoperative days zero, three, six and nine; CONTROL GROUP: no treatment on the wound. Photographs of the lesions were taken on the procedure day and on the 6th and 14th postoperative days, for analyzing the area and the larger diameter of the wound. We carried out euthanasia of all animals on the 14th postoperative day, when we resected he dorsal skin and the underlying muscle layer supporting the wound for histopathological study. RESULTS: there was no statistically significant difference in the percentage of wound closure, in the histopathological findings or in the reduction of the area and of the largest diameter of the wounds among the groups studied on the 14th postoperative day. CONCLUSION: according to the experimental conditions in which the study was conducted, latex cream-gel did not interfere in the healing of acute cutaneous wounds in rats.

Comparison of preoperative quality of life in breast reconstruction, breast aesthetic and non-breast plastic surgery patients: A cross-sectional study.

A breast cancer diagnosis imposes significant emotional and psychological duress. The purpose of this study is to assess the baseline quality of life (QOL) of immediate, delayed, and secondary breast reconstruction patients, comparing these results with QOL in women seeking plastic surgery for cosmetic breast, and non-breast procedures. From 2012 through 2013, immediate (group 1), delayed (group 2), and secondary (Group 3) reconstruction patients, aesthetic breast (group 4) and non-breast plastic surgery patients (group 5) answered Breast-Q questionnaires. Groups 1, 2, 3, 4, and 5 answered 141, 12, 23, 72 and 160 preoperative questionnaires respectively. There was no difference (p = NS) in breast satisfaction, psychosocial well-being, physical well-being-chest, and sexual well-being between groups 1 and 5. Group 1 had higher satisfaction with breast (p < 0.01), psychosocial (p < 0.01) and sexual well-being (p < 0.01) when compared to groups 2 and 4. Group 1 had higher satisfaction with breasts (p < 0.01) compared to group 3. Group 4 did not differ in satisfaction with breasts, psychosocial, and sexual well-being, compared to groups 2 and 3. Group 4 had lower scores in all domains, compared to groups 1 and 5 (p < 0.01). No significant difference in QOL was found between groups 2 and 3. Preoperatively, immediate reconstruction patients had similar satisfaction with breasts, psychosocial well-being, and chest physical well-being, compared to non-breast plastic surgery patients. Aesthetic breast surgery patients demonstrate similar low scores in satisfaction with breasts, psychosocial well-being, and sexual well-being to those of patients prior to delayed breast reconstruction, or secondary salvage procedures.

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.

Effects of metoclopramide on the expression of metalloproteinases and interleukins in left colonic anastomoses. An experimental study.

PURPOSE: To evaluate the effects of metoclopramide on metalloproteinases (MMP) and interleukins (IL) gene expression in colonic anastomoses in rats. METHODS: Eighty rats were divided into two groups for euthanasia on the 3rd or 7th postoperative day (POD), then into two subgroups for sepsis induction or not, and then into subgroups to receive either metoclopramide or saline solution. Left colonic anastomosis were performed and then analyzed. RESULTS: On the 3rd POD, metoclopramide was associated with increased expression of MMP-1a, MMP-13, and TNF-α. On the 7th POD, the transcripts of all MMPs, TNF-α, IL-1ß, IFN-γ, and IL-10 of the treated animals became negatively modulated. In the presence of sepsis, metoclopramide did not change MMPs and decreased IL-6, IL-1ß, IFN-γ and IL-10 gene expression on the 3rd POD. On the 7th POD, increased expression of all MMPs, IFN-γ and IL-10 and negative modulated TNF-α and IL-6 gene expression. CONCLUSION: Administration of metoclopramide increased metalloproteinases and interleukins gene expression on the 3rd postoperative day and negatively modulated them on the 7th POD. In the presence of abdominal sepsis, metoclopramide did not change MMPs and decreased ILs gene expression on the 3rd POD. On the 7th POD, the drug increased expression of all MMPs.

Does CO2 pneumoperitoneum in laparoscopy interfere with collagen deposition in abdominal surgical wounds?

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.

Effect of vitamin K1 supplementation on left colon healing in rats with extrahepatic biliary obstruction.

PURPOSE: To evaluate the effects of vitamin K1 on wound healing in the left colon of rats with experimental biliary obstruction. METHODS: Sixteen male rats, divided into four groups of four animals each (L, M, LK, and MK), underwent colostomy followed by bowel suture in the left colon. Seven days before, animals in the L and LK groups had undergone common bile duct ligation. The animals in groups MK and LK received vitamin K1 supplementation. On day 7 after bowel suture, repeat laparotomy was performed for evaluation of colonic healing by burst pressure measurement and collection of samples for histopathological analysis. Changes in body weight were evaluated in the four groups. RESULTS: Weight loss was lower in animals supplemented with vitamin K. No significant differences were observed in burst pressure among the four groups (p>0.05). Histological analysis showed more hemorrhage and congestion in the biliary obstruction groups. Supplemented animals exhibited increased collagen formation and less edema and abscess formation. CONCLUSION: Vitamin K supplementation attenuated weight loss and improved colonic wound healing in rats.

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.

[Gossypiboma after abdominal surgery is a challenging clinical problem and a serious medicolegal issue]. / Gossipiboma após operação abdominal é situação clínica desafiadora e sério problema médico legal.

INTRODUCTION: The term "gossypiboma" refers to a textile matrix surrounded by foreign body reaction. Gauze and surgical dressings are the most commonly retained materials after laparotomy. AIM: To evaluate the incidence of abdominal gossypiboma, its causes and the preventive measures to reduce the frequence and morbimortality. METHOD: Was conducted a literature review in Medline/Pubmed in english. The survey was about the last 10 years, selecting the headings: gossypiboma, textiloma, retained foreign body and abdominal surgery. Thirty articles were considered in this review. RESULTS: The incidence of gossypiboma is underreported, mostly due to the legal implications of their detection but also because many patients remain asymptomatic. Occur in 1/1000 to 1/1500 of intra-abdominal operations. Clinical presentation is variable, and depends on the location of the foreign body and on the type of inflammatory reaction presented by the host. The recommended course of treatment is excision, which can be accomplished endoscopically, laparoscopically, or via the open route, and seeks to prevent the complications that lead to a high mortality rate. The most important approach is prevention. Preventive measures required include exploration of the abdominal cavity at the end of the procedure, use of textiles with radiopaque markers and a meticulous account of surgical materials. CONCLUSION: Gossypiboma is a former medical-legal problem, whose incidence is apparently increasing. Therefore needs to be revised to take preventive measures in the operating room.

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 metoclopramide on healing of colonic anastomoses in a rat model of abdominal sepsis.

INTRODUCTION: Metoclopramide is often used in the treatment of postoperative nausea and vomiting, but a literature review failed to find reports on the influence of this drug on the healing of bowel anastomoses in the setting of abdominal sepsis. The aim of this study was to evaluate the effects of metoclopramide on the healing of left colonic anastomoses in rats with induced abdominal sepsis. MATERIALS AND METHODS: Forty rats were divided into two groups of 20 animals each to receive either metoclopramide (experimental group: E) or saline (control group: C). Each group was further divided into subgroups of 10 animals each to be killed on the third (E3 and C3) or seventh postoperative day (E7 and C7). A segmental resection of the left colon was performed, followed by end-to-end anastomosis. Sepsis was induced by cecal ligation and puncture. On the day of reoperation, the total number of adhesions was assessed and the anastomosed bowel segment was removed for tensile strength testing, histopathological analysis, measurement of hydroxyproline levels, and histomorphometric evaluation of collagen. RESULTS: Intraoperative findings, number of intra-abdominal adhesions in the anastomosed area, and tensile strength before anastomosis rupture were similar among all subgroups at all assessments. On the third postoperative day, the anastomoses of animals treated with metoclopramide showed significantly lower hydroxyproline levels (p = 0.01) when compared with controls. Collagen content was similar among all subgroups. CONCLUSIONS: Metoclopramide does not have deleterious effects on the healing of bowel anastomoses in rats subjected to experimental abdominal sepsis.

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). Pearson's 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 carbon dioxide therapy on the healing of acute skin wounds induced on the back of rats.

PURPOSE: To evaluate the healing effect of carbon dioxide therapy on skin wounds induced on the back of rats. METHODS: Sixteen rats underwent excision of a round dermal-epidermal dorsal skin flap of 2.5 cm in diameter. The animals were divided into two groups, as follows: carbon dioxide group - subcutaneous injections of carbon dioxide on the day of operation and at three, six and nine days postoperatively; control group - no postoperative wound treatment. Wounds were photographed on the day of operation and at six and 14 days postoperatively for analysis of wound area and major diameter. All animals were euthanized on day 14 after surgery. The dorsal skin and the underlying muscle layer containing the wound were resected for histopathological analysis. RESULTS: There was no statistically significant difference between groups in the percentage of wound closure, in histopathological findings, or in the reduction of wound area and major diameter at 14 days postoperatively. CONCLUSION: Under the experimental conditions in which this study was conducted, carbon dioxide therapy had no effects on the healing of acute skin wounds in rats.

A new proposal for laparoscopic left colectomy in a rat model.

PURPOSE: To evaluate the feasibility and safety of a new technique for laparoscopic segmental colectomy and primary anastomosis in the left colon of rats. METHODS: Thirty rats were randomly assigned to three groups of ten animals each. All animals underwent segmental resection of the left colon and end-to-end anastomosis. In Group I, the animals underwent laparoscopic surgery with carbon dioxide pneumoperitoneum at a pressure of 5 mmHg. In Group II, the animals underwent pneumoperitoneum with carbon dioxide at a pressure of 12 mmHg. In Group III, the control group, the animals underwent open surgery. All animals were reopened on the 7th postoperative day and were evaluated for peritonitis, abscesses, anastomotic dehiscence and bowel obstruction, and the anastomosis bursting pressure was measured. RESULTS: No obstructions, peritonitis or abscesses were found in any of the animals. An animal in Group I exhibited a blocked anastomosis leakage. The average anastomosis bursting pressure in the 30 animals was 187.02 ± 68.35 mmHg. There was no significant difference in the anastomosis bursting pressure among the groups (p = 0.503) CONCLUSION: The laparoscopic experimental model was feasible and safe for segmental colectomy and anastomosis of the left colon in rats.