Quercetin associated with dimethylsulfoxide has a curative effect on experimental colon anastomosis injury

Purpose To examine the effects of quercetin on healing of experimental colon anastomosis injury in early and late period. Methods Eighty male Wistar-Albino rats were divided into 8 groups. For all groups, left colons of the rats were resected and for the rest end-to-end anastomosis was performed. Two of the groups for which the experiment protocol was ended on the 3rd and 7th day following the anastomosis were not administered with either quercetin or dimethylsulfoxide DMSO, whereas two other groups were administered with DMSO only, and four other groups were administered with quercetin dissolved in DMSO in doses of 20 and 100 mg/kg during the protocol. At the end of the study, anastomosis line was resected, histopathological evaluation was performed and bursting pressure, malondialdehyde, superoxide dismutase, catalase, and hydroxyproline levels were measured. Results Quercetin significantly increased hydroxyproline, superoxide dismutase, catalase levels, histopathological healing score, bursting pressure values and decreased malondialdehyde level in early period. It also significantly increased superoxide dismutase, catalase, and hydroxyproline levels and decreased malondialdehyde level in late period. Conclusion It was seen that quercetin speeds up the injury healing process and reveals an antioxidant effect, specifically in early period.(AU)

The influence of platelet-rich plasma (PRP) on colonic anastomosis healing impaired by intraperitoneal 5-flourouracil application: an experimental study

Purpose 5-flourourasil (5-FU) is commonly used for early intraperitoneal chemotherapy in colorectal or appendiceal cancer patients with peritoneal carcinomatosis. Due to its effect, anastomosis healing can be impaired and leads to anastomotic leakage. In this study, we aimed to investigate the potential healing effect of platelet-rich plasma (PRP) on colonic anastomosis impaired by intraperitoneal 5-flourouracil application. Methods After ten rats were sacrificed for preparing PRP, forty Wistar-albino rats were subjected to colonic anastomosis, and randomly allocated into four groups including 10 rats each. According to receiving PRP and/or 5-FU application, the groups were formed as control (C), 5-FU without PRP (CT), anastomosis with PRP (C-PRP), and 5-FU with PRP (CT-PRP). CT and CT-PRP groups also received 5-FU intraperitoneally on postoperative day 1 (POD 1). All animals were euthanized on pod 7. The body weight change, anastomotic bursting pressure (ABP), tissue hydroxiprolin (TH) and histopathological examination of each group were analyzed. Results 5-FU application significantly reduced ABP levels when compared with group C, C-PRP and CT-PRP (for each comparison, p 0,01). PRP application in CT-PRP group raised the measure of ABP up to the levels of C group. Although tissue hydroxyproline levels (THL) levels of CT-PRP group were found higher than CT group, it was not significant (p=0.112). Microscopically, comparing with CT group, PRP application significantly promoted the healing of colonic anastomosis subjected to 5-FU application by improving tissue edema, necrosis, submucosal bridging and collagen formation (p 0.05). Tissue healing in CT-PRP group was observed as good as the control groups. (C, C-PRP, p=0.181, p=0.134; respectively). Conclusion PRP administration on colonic anastomosis significantly promotes the healing process of anastomosis in rats receiving 5-FU. This result encourages further clinical use of PRP to reduce the frequency of AL in patients receiving EPIC.(AU)

Simulated training model of ureteropyelic anastomosis in laparoscopic pyeloplasty

Purpose: To develop a model for simulated training of ureteropyelic anastomosis in laparoscopicpyeloplasty. Methods: Longitudinal and experimental study, with 16 participants. A synthetic instrument was produced to simulate the renal pelvis and the proximal portion of the ureter positioned on a platform within laparoscopic simulators, thereby resulting in the realistic simulation of the ureteropelvic anastomosis. A step-by-step guide was also developed for the accomplishment of the ureteropelvic anastomosis training model. Results: In the evaluation of all participants suture training, a decrease was found in the time needed to perform the anastomosis, with a median of 17.83 min in the 1st step and 14.21 min in the last one (p = 0.01). Regarding the knots, in the 1st step, 5% of them were considered firm, with an evolution to 30% in the last step (p = 0.011). Conclusion: We noticed improvement in the ability to perform the ureteropelvic anastomosis by participants with no experience with it. Therefore, even unexperienced participants can improve their skills with this training. Moreover, we observed the effectiveness of the model use, confirmed by the participants opinion and its validation by expert surgeons.(AU)

Evaluation tool for a gastroenterostomy simulated training

Purpose:To create a checklist to evaluate the performance and systematize the gastroenterostomy simulated training.Methods:Experimental longitudinal study of a quantitative character. The sample consisted of twelve general surgery residents. The training was divided into 5 sessions and consisted of participation in 20 gastroenterostomys in synthetic organs. The training was accompanied by an experienced surgeon who was responsible for the feedback and the anastomoses evaluation. The anastomoses evaluated were the first, fourth, sixth, eighth and tenth. A 10 item checklist and the time to evaluate performance were used.Results:Residents showed a reduction in operative time and evolution in the surgical technique statistically significant (p<0.01). The correlation index of 0.545 and 0,295 showed a high linear correlation between time variables and Checklist. The average Checklist score went from 6.8 to 9 points.Conclusion:The proposed checklist can be used to evaluate the performance and systematization of a simulated training aimed at configuring a gastroenterostomy.(AU)

Rectal application of argan oil improves healing of colorectal anastomosis in rats

Purpose: To investigate the possible effects of argan oil on the healing of colorectal anastomoses. Methods: I n Group 1 (sham), laparotomy was performed and the colon was mobilized. In the control (Group 2) and argan oil (Group 3) groups, colonic resection and anastomosis were applied. To the control and sham groups, 2 mL of 0.9% NaCl was administred rectally, and in the argan oil group, 2 mL/day argan oil was applied rectally for 7 days. Results: The mean bursting pressures of the argan oil and sham groups were significantly higher than the values in the control group. A significant difference was determined between the tissue hydroxyproline and prolidase levels of control group and other groups. Histopathologically, argan oil showed significant beneficial effects on colonic wound healing. In the argan oil and sham groups, the tissue malondialdehyde and fluorescent oxidation product levels were found to be lower and total sulfhydryl levels were higher than the control group. Conclusions: The rectally administered argan oil was observed to have significantly ameliorated wound healing parameters and exerted a significant antioxidant effect. This is the first study in the literature about the beneficial effects of argan oil on colorectal anastomoses.(AU)

Bacterial cellulose to reinforce urethrovesical anastomosis. A translational study

Purpose: To evaluate the efficacy of the cellulosic exopolysaccharide membrane (CEM) as a urethral reinforcement for urethrovesical anastomosis. Methods: Twenty eight rabbits were submitted to urethrovesical anastomosis with or without CEM reinforcement. The animals were divided into 4 groups: C7, CEM7, C14 and CEM14: (C= only anastomosis or CEM = anastomosis + CEM), evaluated after 7 weeks, and 14 weeks. The biointegration and biocompatibility of CEM were evaluated according to stenosis, fistula, urethral wall thickness, urethral epithelium, rate of inflammation and vascularization. Results: Between the two experimental groups, the difference in the number of stenosis or urinary fistula was not statistically significant. The morphometric analysis revealed preservation of urethral lumen, well adhered CEM without extrusion, a controlled inflammatory process and implant vascularization. The urothelium height remained constant over time after CEM reinforcement and the membrane wall was thicker, statistically, after 14 weeks. Conclusion: The absence of extrusion, stenosis or urinary fistula after 14 weeks of urethrovesical anastomosis demonstrates cellulosic exopolysaccharide membrane biocompatibility and biointegration with tendency to a thicker wall.(AU)

Simulated training of a laparoscopic vesicourethral anastomosis

Purpose: To develop a model and curriculum for simulated training of an effective and well accepted laparoscopic vesicourethral anastomosis (VUA). Methods: Experimental longitudinal study of quantitative character. The sample consisted of 12 general surgery residents and 6 urology residents (R3). The training consisted of making twelve VUAs on synthetic organs. The training was divided into four sessions and accompanied by an instructor who performed positive feedback. The evaluation of the anastomoses considered the time and the analysis of the operative technique through the global evaluation scale Objective Structured Assessment of Technical Skills (OSATS). Results: Residents showed a reduction in operative time and evolution in the surgical technique statistically significant (p<0.01). The best-rated items were the facilitator positive feedback and the fact that the training was carried out at the teaching hospital premises. Conclusions: The proposed training model was well accepted and proved to be effective in reducing operative time and improving laparoscopic skills. The training should be fractionated (4 sessions in 3 weeks), repetitive (12 anastomoses) and have positive feedback.(AU)

Model for simulated training of laparoscopic gastroenterostomy

Purpose: To develop a model of gastroenterostomy and to analyze the acquisition of skills after training by simulation. Methods: Experimental longitudinal study and of a quantitative character. The sample consisted of twelve general surgery residents from four hospitals. The training consisted of making ten anastomoses divided equally into five sessions and it took place over a period of six weeks. The evaluation of the anastomoses considered the time and the analysis of the operative technique through the global evaluation scale Objective Structured Assessment of Technical Skills (OSATS). Results: Residents showed a reduction in operative time and evolution in the surgical technique statistically significant (p 0.01). The correlation index of 0.545 and 0.497 showed a high linear correlation between time variables and OSATS. Conclusion: The preparation of ten gastroenterostomies is an exercise capable of transferring basic and advanced skills in laparoscopy through a standardized training using synthetic organs and a simulator.(AU)

Vertical gastrectomy in overweight and non-overweight rats

PURPOSE:To compare the two lines suture (total and seromuscular) after partial gastrectomy in normal and overweight rats.METHODS:Forty Wistar rats were distributed in two groups. Group A received normal diet; group B, normal diet and supplementation with saccharose in the water. When group B progressed to a statistically greater weight than the animals of group A, the experiment (sleeve-like gastrectomy) was conducted with gastrorraphy in two sutures lines (total and seromuscular).The animals were distributed into two subgroups of 10. A1 and A2 subgroups were sacrificed at 7 and 14 days postoperatively as well as B1 and B2. Mortality, morbidity, complications attributed to the gastric suture, biochemical dosages, Lee index, macroscopy, weight of retroperitoneal and gonadal fat, optical microscopy with hematoxylin-eosin and picrosirius-red, were the evaluation parameters.RESULTS:The overweight group achieved statistically greater weight after 16 weeks in induced obesity; there was no mortality or complications with clinical consequences attributable to morbidity. The overweight group had statistically greater weight of gonadal and retroperitoneal fat. The difference was observed in urea, albumin, total cholesterol and indirect bilirubin.CONCLUSION:There was no outcome difference between the overweight and non-overweight group in two suture lines in gastrorrhaphy after sleeve-like gastrectomy.(AU)

Effect of ozone on colon anastomoses in rat peritonitis model

PURPOSE:To investigate the effects of medical ozone theraphy on the colon anastomosis of peritonitis model in rats.METHODS:Eighteen rats were randomly assigned into three equal groups; control, cecal punctuation and colon anastomosis and ozone theraphy. Sepsis was performed with a cecal punctuation in groups 2 and 3. The medical ozone theraphy was administered intraperitonealy for three weeks in group 3 while the other rats received saline injection. At the twenty second day serum were obtained for TNF-α and IL-1β, the colonic burst pressures were measured and colonic tissue samples were obtained for MDA and MPO levels. Histolopatological examination was evaluated with H&E stain, and Ki-67, IL-1β and the VEGF immunostaining densities were also compared.RESULTS:Intraperitoneal ozone administration reversed TNF-α, IL-1β, MDA and MPO levels and the colonic burst pressures. There was also a significant difference at immunostaining densities of histopathological examination.CONCLUSION:Medical ozone therapy may contribute to tissue healing by affecting the proliferation and the vascularization thus has benefits on colonic anastomosis at peritonitis in rats.(AU)

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

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-. On the 7th POD, the transcripts of all MMPs, TNF-, IL-1, IFN-, 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-1, IFN- and IL-10 gene expression on the 3rd POD. On the 7th POD, increased expression of all MMPs, IFN- and IL-10 and negative modulated TNF- 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.(AU)

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.(AU)

Influence of the peritoneal lavage with bupivacaine on the survival and resistance of colonic anastomoses performed under fecal peritonitis in rats

PURPOSE: To evaluate the effects of peritoneal lavage with bupivacaine on survival and initial resistance of anastomosis on distal colon, performed under peritonitis or not. METHODS: Forty rats, weighing from 300 to 350g (321.29±11.31g), were randomly divided in four groups and underwent laparotomy and anastomosis on the distal colon six hours after induction of peritonitis by intraperitoneal injection of autologous fecal material or not. Group 1: No peritonitis and lavage with 3ml NS; Group 2: No peritonitis and lavage with 8 mg.kg-1 (± 0.5 mL) of 0.5% bupivacaine added to 2.5 mL of NS; Group 3: Peritonitis and lavage with 3ml NS; Group 4: Peritonitis and lavage with 8 mg.kg-1 (± 0.5 mL) of 0.5% bupivacaine added to 2.5 mL of NS. Necropsies were performed on the animals that died and the time of death was recorded. Surviving animals were submitted to euthanasia on the fifth post-operative day and Total Energy of Rupture biomechanical test (TER) was applied. RESULTS: Group 4 showed survival increase compared to Group 3, without statistical significance. Group 3 presented the smallest average TER, with statistical significance. CONCLUSION: Peritonitis increased mortality and influenced negatively the resistance of colic anastomosis in rats. Peritoneal lavage with bupivacaine increased anastomotic resistance.(AU)

A modified microsurgical model for end-to-side selective portacaval shunt in the rat: intraoperative microcirculatory investigations

PURPOSE: To investigate the intraoperative microcirculatory changes of the affected organs (small bowel, liver and kidney) during the making of a modified selective portacaval (PC) shunt. METHODS: On ten anaesthetized Sprague-Dawley rats the selective end-to-side mesocaval anastomosis was performed, where only the rostral mesenteric vein is utilized and the portal vein with the splenic vein are left intact. Morphometric and microcirculatory investigations using a LDF device determining flux units (BFU) were carried out. RESULTS: After completing the shunts the microcirculatory flux values did not recover in the same manner on the surface of the small intestine, the liver or the kidney. BFU values showed deterioration in the small intestine and in the liver (p<0.001). During the reperfusion the BFU values improved, but not in the same manner. The small intestine values left behind the kidney and liver data. CONCLUSIONS: Technically, the advantages of the models include the selective characteristic, the mesocaval localization and the relatively easy access to those vessels. However, its major disadvantage is the time needed for positioning the vessels without coiling or definitive stretching. Intraoperative LDF may provide useful data on the microcirculatory affection of the organs suffering from hypoperfusion or ischemia during creating the shunts.(AU)

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.(AU)

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.(AU)

Effects of preoperative irradiation using fractioned electron beam on the healing process of colocolonic anastomosis in rats undergoing early and late surgical intervention

PURPOSE: To investigate the effects of preoperative fractioned irradiation using an electron beam on the healing process of colocolonic anastomoses in rats that underwent early and late surgical intervention. METHODS: Thirty Wistar rats, distributed as follows: group A (surgery only), group B (fractionated irradiation for 30 days (if), surgery seven days after the end of it), group C (if for 30 days, and surgery after 30 days of termination). On the seventh postoperative day the anastomotic segment analysis was taken, using tension tests, histology and collagen deposition evaluation by computerized analysis. RESULTS: Regarding the tension resistance of the anastomosis, there were no statistical differences (p=0.42). However, a significant increase in cells number in the inflammatory infiltrate in the group with a longer interval between surgery and pre op radiation (p<0.05). The collagen concentration had no significant variance. CONCLUSION: The irradiation in divided doses increased local inflammatory cellularity when the surgery was performed later. This result did not affect the increase of complications, nor on the local concentration of collagen, achieving similar clinical outcomes.(AU)

Cecorraphy in single layer using polypropylene and poliglecaprone 25 threads: comparative study in rats / Cecorrafia em plano único com fios de polipropileno e poliglecaprone 25: estudo comparativo em ratos

PURPOSE: To compare sutures with polypropylene and poliglecaprone 25 after partial cecotomy in rats. METHODS: Thirty six rats divided into two groups, A and B, of 18 animals; each group was also divided into three subgroups of six animals sacrificed at 4th, 7th and 14th days after surgery. Were studied the mortality, morbidity, complications attributable to sutures, macroscopy, optical microscopy and measurement of hydroxyproline at the level of the suture. RESULTS: There were no deaths or wound complications such as hematoma, seroma, abscess, evisceration or eventration. On microscopic evaluation reepithelization, coaptation and inflammation in both groups did not differ significantly. The average rate of tissue hydroxyproline found in the samples on the 4th day after surgery, was 21.38 mg/g tissue for group A and 16.68 mg/g for group B; on day 7 after surgery, the average was 15.64 mg/g tissue for group A and 26.53 mg/g for group B; on day 14, the average was 8.09 mg/g tissue for group A and 25.07 mg/g for group B. CONCLUSION: There were no differences on clinical evolution, macroscopic aspect, microscopic data and hydroxyproline concentration on both sutures.(AU)

OBJETIVO: Comparar a sutura com fio de polipropileno e poliglecaprone 25 após cecotomia parcial em ratos. MÉTODOS: Trinta e seis ratos foram distribuídos em dois grupos A e B de 18 animais, e cada grupo foi dividido em três subgrupos de seis, sacrificados no 4º, 7º e 14º dias do pós-operatório. Estudou-se a mortalidade, morbidade, complicações atribuíveis às suturas, macroscopia, microscopia ótica e dosagem de hidroxiprolina no nível da sutura. RESULTADOS: Não houve mortalidade ou complicações da ferida operatória como hematoma, seroma, abscesso, evisceração ou eventração. Na avaliação microscópica os critérios de re-epitelização, coaptação e processo inflamatório ambos os grupos não apresentaram diferença significativa. A taxa tecidual média da hidroxiprolina encontrada nas amostras no 4º dia de pós-operatório foi de 21,38 mg/g de tecido para o grupo A e 16,68 mg/g para o grupo B; no 7º dia a média foi de 15,64 mg/g de tecido para o grupo A e 26,53 mg/g para o grupo B; no 14º dia ela foi de 8,09 mg/g de tecido para o grupo A e 25,07 mg/g para o grupo B. CONCLUSÃO: Não houve diferença estatística entre a evolução clínica, avaliação macroscópica, microscopia e dosagem de hidroxiprolina entre as suturas realizadas com os fios estudados.(AU)

Effects of chitosan on healing and strength of colonic anastomosis in rats / Efeitos de quitosana na cicatrização e resistência de anastomose colônica em ratos

PURPOSE: To investigate whether chitosan application over colonic anastomosis line, provide reinforcement, and subsequently improve anastomotic healing. METHODS: Forty eight Wistar albino female rats were used and were randomly divided into four groups, 12 rats in each: The control groups (1 and 3) received no further treatment. The experimental groups (2 and 4) received chitosan application over the colonic anastomosis. After sacrifying rats at the end of the experiment (either on day three or on day seven, depending on the group), colonic bursting pressure, a hihydroxyproline level and histopathologic characteristics of the perianastomotic tissue were examined. RESULTS: At three days, chitosan and control groups had similar values for histopathologically. On day seven, chitosan group had significantly higher mean score of collagenization (p=0.007) and a significantly higher bursting pressure (p=0.038). CONCLUSION: Our study emphasizes the positive effect of chitosan in the process of collagenation in colonic anastomosis healing.(AU)

OBJETIVO: Investigar se a aplicação de quitosana em anastomose colônica promove resistência à tração e consequentemente a melhora na cicatrização. MÉTODOS: Foram utilizados 48 ratos Wistar fêmeas distribuídos em quatro grupos, 12 ratos em cada. Grupos controle (1 e 3) não receberam tratamento. Grupos experimento (2 e 4) receberam aplicação de quitosana na anastomose colônica. Após eutanásia após 3º ou 7º dias foram examinadas a tensão, o nível de hidroxiprolina e aspectos histopatológicos da anastomose. RESULTADOS: Após três dias os grupos controle e quitosana não apresentaram alterações histopatológicas. No sétimo dia o grupo quitosana apresentou significante elevação do escore de colagenização (p=0,007) e da tensão de ruptura (p=0,038). CONCLUSÃO: A quitosana apresentou bons resultados nos processos de colagenização e cicatrização de anastomose colônica.(AU)

Evaluation of the effects of S-methylisothiourea hemisulfate, an inducible nitric oxide synthase inhibitor, on the healing of colonic anastomosis in rats / Avaliação dos efeitos da S-metilisotiouréia, um inibidor da enzima óxido nítrico sintase induzível, na cicatrização de anastomoses colônicas em ratos

PURPOSE: To evaluate the effects of S-methylisothiourea hemisulfate (SMT) on the healing of colonic anastomosis in rats. METHODS: Sixty rats Wistar were distributed into two groups of 30 animals: experimental (E) and control C). The animals of experimental group received intraperitoneal SMT at 50mg/kg/dose every 12 hours for 72 hours. The control group received intraperitoneal saline at the same volume of SMT. The rats were subdivided into subgroups groups of 10 for euthanasia on the third, seventh, and 14th postoperative days (POD). We evaluated clinical and weight evolution, breaking strength and histopathology; also, a blood sample was collected for serum dosage of nitrite/nitrate. RESULTS: There was more vascular neoformation (p=0.006) and granulation (p=0.002) in the E3 group, and more mononuclear infiltrates in the C3 group (p=0.041). There was also more edema in the C14 group (p=0.008). There was no statistically significant difference in breaking strength, nitrite/nitrate dosage, and the remaining histopathological parameters. CONCLUSION: The use of S-methylisothiourea hemisulfate improved the healing of colonic anastomosis in rats on the third postoperative day by accelerating the proliferative stage of healing, but without interfering with the breaking strength of the anastomosis.(AU)

OBJETIVO: Avaliar os efeitos do hemissulfato de S-metilisotiouréia (SMT) na cicatrização de anastomoses colônicas em ratos no terceiro, sétimo e 14° dia de pós-operatório (DPO). MÉTODOS: Sessenta ratos Wistar foram distribuídos em dois grupos: experimental (E) e controle (C), com 30 animais cada. No grupo experimental foi administrado SMT 50mg/kg/dose, intraperitoneal a cada 12 horas por 72 horas. O grupo controle recebeu NaCl a 0,9%. Os ratos foram subdivididos em grupos de 10 para eutanásia no terceiro, sétimo e 14° DPO. Avaliou-se a evolução clínica e o peso dos animais, a resistência tênsil e histopatologia da anastomose, e a dosagem de nitrito/nitrato no soro. RESULTADOS: Houve mais neoformação vascular (p=0,006) e de granulação (p=0,002) no grupo E3, e maior infiltração de mononucleares no grupo C3 (p=0,041). Houve também mais edema no grupo C14 (p=0,008). Não houve diferença estatisticamente significativa na resistência tênsil, a dosagem de nitrito / nitrato, e os restantes parâmetros histopatológicos. CONCLUSÃO: A utilização do hemissulfato de S-metilisotiouréia acelerou a cicatrização das anastomoses colônicas, a melhoria ocorreu no terceiro DPO: verificou-se que a fase proliferativa da cicatrização foi acelerada. Não houve interferência na resistência tênsil das anastomoses.(AU)