Effects of antiadhesive agents on the healing of intestinal anastomosis

Anti-Adhesive, Platelet Gathering Effects of c-RGD Modified Poly(p-dioxanone-co-l-Phe) Electrospun Membrane and Its Comprehensive Application in Intestinal Anastomosis

Intestinal resection and anastomosis are performed in over a million people with various bowel diseases annually. Excessive fibrosis and anastomotic site leakage are the main complications of anastomosis surgery, despite great improvements in operative technique and equipment in recent years. In this study, cRGD modified poly(p-dioxanone-co-l-Phe) (PDPA) membranes are designed and applied in intestinal anastomosis to simultaneously solve the two aforementioned complications. cRGD is modified onto PDPA membranes through both physical absorption and π-π accumulation between d-Phe of cRGD and l-Phe of PDPA. Although cRGD modification enhanced the biocompatibility of PDPA membranes, cRGD modified PDPA membrane suppresses fibroblast proliferation both in vitro and in vivo as a result of degradation and subsequent release of fibroblast suppressive l-Phe from PDPA. Meanwhile, platelets are entrapped by cRGD modified PDPA membranes through the specific binding of cRGD and platelet GP_IIbIIIa . cRGD modified PDPA membranes are applied in rat intestinal anastomosis, and both adhesion and stenosis are successfully prevented at anastomotic sites. At the same time, bursting pressure, which represents healing intensity at anastomotic sites, is promoted. The gathering and activation of platelets on PDPA membranes induce secretion of autologous PDGF and VEGF to facilitate angiogenesis and subsequent healing of anastomotic sites.

Effect of 4DryField® PH, a Novel Adhesion Barrier, on Recurrence of Intestinal Adhesions after Extensive Visceral Adhesiolysis

Background

Adhesions occur after up to 97% of abdominal interventions causing chronic pain, infertility, and intestinal obstruction. Various concepts to prevent adhesions have been presented but mostly either have low efficacy or are not applicable in resective intestinal surgery or incomplete hemostasis. In this retrospective one-center clinical trial, the course of patients with extensive abdominal adhesiolysis and application of a recent starch-based formulation, 4DryField PH (4DF), is analyzed.

Case Report

Five female patients (age 65–83 years) underwent extensive open adhesiolysis with application of 4DF gel for adhesion prevention, premixed extracorporeally with saline or Ringer's solution (60–70 mL per 5 g 4DF) for homogeneous gel distribution on intestinal loops and in the peritoneal cavity. In addition, dry 4DF powder was dispersed on the greater omentum and subsequently transformed into a gel by dripping with saline or Ringer's solution directly before abdominal closure. Patients were followed up for more than two years, except for one patient who died after nine months due to metastases. One patient with complex situation due to Gore-Tex mesh in the lower abdomen showed no adhesions at scheduled second-look operation but after six months had relaparotomy for adhesiolysis. All other patients have remained free of adhesions or adhesion-related symptoms during follow-up.

Conclusion

Considering the extent and complexity of adhesions, treatment with 4DF gel for adhesion prevention after open adhesiolysis appears promising. Prospective randomized trials should further elaborate on this clinical concept.

Effects of albumin/glutaraldehyde glue on healing of colonic anastomosis in rats

AIM

To evaluate the effect of local surgical adhesive glue (albumin/glutaraldehyde-Bioglue) on the healing of colonic anastomoses in rats.

METHODS

Forty Albino-Wistar male rats were randomly divided into two groups, with two subgroups of ten animals each. In the control group, an end-to-end colonic anastomosis was performed after segmental resection. In the Bioglue group, the anastomosis was protected with extraluminar application of adhesive glue containing albumin and glutaraldehyde. Half of the rats were sacrificed on the fourth and the rest on the eighth postoperative day. Anastomoses were resected and macroscopically examined. Bursting pressures were calculated and histological features were graded. Other parameters of healing, such as hydroxyproline and collagenase concentrations, were evaluated. The experimental data were summarized and computed from the results of a one-way ANOVA. Fisher’s exact test was applied to compare percentages.

RESULTS

Bursting pressures, adhesion formation, inflammatory cell infiltration, and collagen deposition were significantly higher on the fourth postoperative day in the albumin/glutaraldehyde group than in the control group. Furthermore, albumin/glutaraldehyde significantly increased adhesion formation, inflammatory cell infiltration, neoangiogenesis, and collagen deposition on the eighth postoperative day. There was no difference in fibroblast activity or hydroxyproline and collagenase concentrations.

CONCLUSION

Albumin/glutaraldehyde, when applied on colonic anastomoses, promotes their healing in rats. Therefore, the application of protective local agents in colonic anastomoses leads to better outcomes.

Comparison of effects of the tacrolimus and cyclosporine A on the colon anastomosis recovery of rats

Purpose

This study aims to examine and compare the effects of immunosuppressant cyclosporine A (CsA) and tacrolimus (TAC) on colon anastomosis recovery.

Methods

Forty rats were randomly divided into 4 groups. The 4 groups were determined as follows: control group; sham group, given %0.09 NaCl; TAC group, given 0.5 mg/kg/day tacrolimus; and CsA group, given 5 mg/kg/day CsA. A 6-cm midabdomen incision was performed on the rats. An incision of all layers on the right colon was performed. Then anastomosis was undertaken. Laparotomy was performed on the seventh day postoperation. The colon bursting pressures were evaluated, histopathological examinations were undertaken, and E-cadherin expression and tissue hydroxyproline levels were evaluated.

Results

Statistically significant differences were observed among bursting pressures of the groups (P < 0.001). The value was significantly low in TAC and CsA groups when compared to control and sham groups (P < 0.05). The tissue hydroxyproline levels were significantly low in TAC group compared to control group (P = 0.03). Fibroblast density and neovascularization were significantly greater in the control group compared to the TAC group (P < 0.05). Levels of collagen had decreased significantly in TAC group compared to other groups (P < 0.05).

Conclusion

Our study showed that TAC may have a negative effect of colon anastomosis recovery. The lowest anastomosis bursting pressure was detected in TAC group. Also, collagen, hydroxyproline, fibroblast, neovascularization and E-Cadherin levels were comparatively lower in TAC group. CsA did not cause any significant changes to tissue hydroxyproline, collagen, fibroblast, and E-Cadherin levels.

Effect of "phase change" complex on postoperative adhesion prevention

BACKGROUND

Postsurgical peritoneal adhesion is a major clinical problem. Numerous anti-adhesion products have been studied, but none could be easily used to provide a physical barrier. In this study, we developed a "phase change" anti-adhesion barrier for reducing peritoneal adhesion by cross-linked copolymerization of O-carboxymethyl chitosan (CMC) and CaCl2 and addition of cyclosporin A (CsA).

MATERIALS AND METHODS

The CMC-CaCl2-CsA compound was characterized by equilibrium swelling rate, weight loss, releasing effect, and coagulation test, and its biosafety was characterized by acute oral toxicity, hemolysis, and cytotoxicity. Intestinal adhesion model was applied on 64 Sprague-Dawley rats, which received CMC, CMC-CaCl2, or CMC-CaCl2-CsA treatment. At postoperative days 7 and 14, the rats were euthanized, and adhesions were graded by an investigator blinded to the treatment groups, using a predetermined adhesion scoring system. The cecum and adhesion tissue were stained with hematoxylin and eosin and antibodies for matrix metalloproteinase-9 and TIMP-1 for further histopathologic examination.

RESULTS

The phase change anti-adhesive material exhibited effective blood clotting and were nontoxic in clotting experiments and acute toxicity test. The degradation rate could be adjusted using phosphate-buffered solution with varying pH. Adhesions were significantly reduced in the CMC-CaCl2-CsA treatment group compared with the control group (P < 0.001). Expression of matrix metalloproteinase-9 was stronger in CMC-CaCl2-CsA treatment group at 7 days after surgery.

CONCLUSIONS

"Phase-change" adhesive can undergo changes after application, and it inhibits the formation of abdominal adhesions after surgery. The material is convenient for using by surgeons and provides an effective tool for intestinal adhesion prevention.

Pharmacological interventions for improved colonic anastomotic healing: A meta-analysis

AIM: To identify pharmaceuticals for the prophylaxis of anastomotic leakage (AL), we systematically reviewed studies on anastomosis repair after colorectal surgery.

METHODS: We searched PubMed and EMBASE for articles published between January 1975 and December 2012. We included studies in English with the primary purpose of promoting healing of anastomoses made in the colon or rectum under uncomplicated conditions. We excluded studies on adverse events from interventions, nutritional interventions or in situ physical supporting biomaterials. The primary outcome was biomechanical strength or AL. We performed meta-analyses on therapeutic agents investigated by three or more independent research groups using the same outcome. The DerSimonian-Laird method for random effects was applied with P < 0.05.

RESULTS: Of the 56 different therapeutic agents assessed, 7 met our inclusion criteria for the meta-analysis. The prostacyclin analog iloprost increased the weighted mean of the early bursting pressure of colonic anastomoses in male rats by 60 mmHg (95%CI: 30-89) vs the controls, and the immunosuppressant tacrolimus increased this value by 29 mmHg (95%CI: 4-53) vs the controls. Erythropoietin showed an enhancement of bursting pressure by 45 mmHg (95%CI: 14-76). The anabolic compound growth hormone augmented the anastomotic strength by 21 mmHg (95%CI: 7-35), possibly via the up-regulation of insulin-like growth factor-1, as this growth factor increased the bursting pressure by 61 mmHg (95%CI: 43-79) via increased collagen deposition. Hyperbaric oxygen therapy increased the bursting pressure by 24 mmHg (95%CI: 13-34). Broad-spectrum matrix metalloproteinase inhibitors increased the bursting pressure by 48 mmHg (95%CI: 31-66) on postoperative days 3-4. In the only human study, the AL incidence was not significantly reduced in the 103 colorectal patients treated with aprotinin (11.7%) compared with the 113 placebo-treated patients (9.7%).

CONCLUSION: This systematic review identified only one randomized clinical trial and seven therapeutic agents from pre-clinical models that could be explored further for the prophylaxis of AL after colorectal surgery.

The effect of postoperative hyperbaric oxygen treatment on intra-abdominal adhesions in rats

Abdominal adhesions, whether caused by peritoneal trauma, radiation, infection, or a congenital condition, are associated with a wide range of complications. These complications include chronic abdominal or pelvic pain, infertility, and adhesive small bowel obstruction. Such adhesions render re-operation difficult, with attendant risks of inadvertent enterostomy and increased operation time. The purpose of this study was to investigate the potential of hyperbaric oxygen (HBO) therapy in the prevention of abdominal adhesions in an experimental animal study. A laparotomy was performed on Wistar rats to induce the formation of adhesions on the cecum and the intra-abdominal area (1 × 2 cm). A superficial layer of the underlying muscle from the right abdominal wall was also shaved and prepared for aseptic surgery. The rats were divided into four groups according to the duration of HBO therapy; five additional groups were designated according to the conditions of HBO therapy. When the rats were evaluated according to adhesion area and grade, a statistically significant difference was observed between the control and HBO treatment groups (p < 0.005). Results from this study suggest that HBO treatment could reduce adhesion formation; and further suggest that HBO therapy may have therapeutic potential in the treatment of postoperative peritoneal adhesion.

Cellular responses to electrospun membranes made from blends of PLLGA with PEG and PLLGA-b-PEG

Control of cellular responses is crucial for the use of electrospun membranes in biomedical applications, including tissue engineering or biomedical devices. However, it is still unclear whether adhesion and proliferation of fibroblasts is stimulated or inhibited on polyethylene glycol (PEG)-modified electrospun membranes. In this study, poly(L-lactide-co-glycolide) (PLLGA)-PEG copolymer and pure PEG were blended with PLLGA, and then electrospun onto nonwoven membranes. The effects of blending of PLLGA-PEG or pure PEG on the adsorption of proteins, and further on the adhesion and proliferation of L929 fibroblasts on the electrospun membranes were investigated. Addition of PLLGA-PEG or PEG significantly improved the hydrophilicity of the electrospun membranes. Pure PEG had no obvious effects on the growth of L929 fibroblasts; in contrast, PLLGA-PEG significantly inhibited the adsorption of proteins and the proliferations of the cells on the electrospun membranes. In response to diminished protein adsorption, mRNA expression of genes related to cell adhesion and migration was up-regulated. The limited effects of pure PEG were probably caused by its preferential dissolution, whereas membrane-confined PLLGA-PEG displayed excellent performance on the inhibition of protein adsorption and cell proliferation.

Prevention of peritoneal adhesions by intraperitoneal administration of vitamin E and human amniotic membrane

BACKGROUND

Our objective was to evaluate the comparative effectiveness of intraperitoneally administered vitamin E and human amniotic membrane in preventing postoperative intraperitoneal adhesion formation.

MATERIAL AND METHODS

75 Wistar-albino rats were separated into 5 groups: Group 1 (control), Group 2 (intraperitoneal olive oil, the diluent of vitamin E), Group 3 (Intraperitoneal vitamin E diluted in olive oil), Group 4 (Amniotic membrane group) and Group 5 (Amniotic membrane and Intraperitoneal vitamin E diluted in olive oil). The same experimental method, consisting of cecal abrasion and ligature of the adjacent parietal peritoneum, was used in all rats to produce adhesions. Relaparotomy was performed on the 15th postoperative day. intra-abdominal adhesions were scored according to macromorphological characteristics and adhesion-carrying tissues underwent standard histologic examination. Inflammation, vascularization and fibrosis in granulation sites were graded in all samples. The results were analyzed using a Mann-Whitney-U test.

RESULTS

In terms of inflammation, neovascularization and fibrosis scores obtained by histology and macromorphologic adhesion scores. There were no significant differences between Groups 1 and 2 (p=0.176). The results of Groups 3, 4 and 5 showed a significant difference when compared with both Group 1 and 2 (p=0.001). The difference between Groups 3, 4 and 5 were not significant with respect to these 4 parameters.

CONCLUSION

Intraperitoneal vitamin E and amniotic membrane treatment were both effective in the prevention of peritoneal adhesions. The combination of these agents did not produce a synergistic effect. Easy applicability of the intraperitoneal administration of vitamin E was its major advantage.

Does low molecular weight heparin impair anastomotic wound healing?

BACKGROUND

Enoxaparin is an important molecule which had been using in prophylaxis and treatment of deep venous thrombosis. Also, it is showed that it prevents postsurgical peritoneal adhesions in rats. It is aimed to evaluate its effects on gastrointestinal wound healing.

METHODS

Thirty Wistar albino rats were divided into three groups as control, subcutan, and intraperitoneal enoxaparin groups. Left colon anastomoses were performed. On postoperative seventh day, anastomotic healing was evaluated by measuring anastomotic bursting pressure, tissue hydroxyproline levels, and histopathological examination.

RESULTS

The anastomotic bursting pressure was highest in subcutan enoxaparin group (p < 0.001), intraperitoneal enoxaparin group (p < 0.01) came the second, and the control group has the worst value. The hydroxyproline results were found nearly similar to the bursting pressure values (subcutan (p < 0.001) > intraperitoneal (p < 0.05) > control). Neovascularization in subcutan group (p < 0.001) has a statistically significant difference to other groups.

CONCLUSION

Enoxaparin did not interfere with colonic anastomotic resistance but improved the intestinal wound healing.

Preventing intraperitoneal adhesions with vitamin E and sodium hyaluronate/carboxymethylcellulose: a comparative study in rats

PURPOSE

To compare the effectiveness of intraperitoneally administered vitamin E with the sodium hyaluronate/carboxymethylcellulose membrane (HA/CBMC) in preventing postoperative intraperitoneal adhesion formation.

METHODS

Sixty Wistar rats underwent a laparotomy and adhesions were induced (IA). The animals were divided into four groups: group 1, control (IA); group 2 (IA + Vitamin E): group 3 (IA+HA/CBMC) and group 4 (IA+ Vitamin E + HA/CBMC). The Vitamin E (groups 2 and 4) and HA/CBMC (groups 3 and 4) were administered intraperitoneally before the abdominal wall was closed. After 30 days, adhesions were classified by an independent surgeon.

RESULTS

Three animals died; one from group 3 and two from group 4. All control animals had substantial adhesions compared with unsubstantial adhesions observed in 11/15 in group 2 (P = 0.000), 11/14 in group 3 (P = 0.001), and 10/13 in group 4 (P = 0.000).

CONCLUSION

Vitamin E, administered intraperitoneally, is as effective as HA/CBMC in preventing postoperative adhesions.

Anastomose colônica com adesivo de fibrina em ratos diabéticos

OBJETIVO: Estudar aspectos da cicatrização na anastomose colônica com adesivo de fibrina em ratos normais e diabéticos. MÉTODO: Foram utilizados 160 ratos Wistar (Rattus novergicus albinus), machos, com peso variando de 250 a 300g, sendo que oitenta destes animais eram não diabéticos e os outros oitenta animais apresentavam diabetes mellitus induzido pela aloxana, Os animais foram submetidos a procedimento operatório padronizado que consistiu em colectomia parcial esquerda e anastomose primária por sutura manual ou com adesivo de fibrina. Foram reavaliados no quarto ou sétimo dia de pós-operatório quando se observou a presença de coleção líquida ou purulenta na tela subcutânea; integridade da sutura; presença de aderências; presença de deiscência; resistência da anastomose (pressão máxima de insuflação) em mmHg, e a concentração tecidual de hidroxiprolina. RESULTADOS: Em relação à presença de deiscência de anastomose e mortalidade ocorreram piores resultados nos animais diabéticos no quarto e sétimo dias de observação em comparação ao controle. Nos grupos e subgrupos estudados os resultados com o uso do adesivo de fibrina não foram melhores que os da sutura manual. Em relação à concentração tecidual de hidroxiprolina não houve diferença significativa entre os grupos. CONCLUSÃO: O diabetes mellitus induzido pela aloxana impede a reparação normal da anastomose colônica em ratos e o uso adesivo de fibrina na anastomose colônica em ratos normais e diabéticos não trouxe benefícios na evolução pós-operatória.

Colorectal anastomotic leakage: a new experimental model

BACKGROUND

Anastomotic leakage is the major complication after colorectal surgery. To date, animal experiments concerning colorectal anastomosis focus on anastomotic healing instead of anastomotic leakage. This study aims to develop a new experimental model for colorectal anastomotic leakage.

METHODS

A control group, receiving an anastomosis with 12 interrupted sutures, was compared to a group receiving an anastomosis with 6 interrupted sutures. When the leakage rate was observed to be too low, the number of sutures was decreased stepwise, to 5 or less. Each group contained 9 "C57Bl6-mice". After 7 d the Anastomotic Bursting Pressure (ABP) was determined.

RESULTS

In the first experiment, one mouse (11.1%) in the case group and none in the control group developed leakage. Average ABP was 152.2 mmHg in the control group and 138,8 mmHg in the case group (P=0.111). In the second experiment, case group receiving an anastomosis with 5 sutures, 4 mice (44.4%) in the case group developed leakage. This experiment was repeated twice resulting in leakage rates of 33.3% and 44.4%. The average overall ABP in the case group was 142.7 mmHg vs. 179.9 mmHg (P=0.022) in the control group. The mice without leakage showed a stabilization of average weight loss around day 2 and 3 and a decrease afterwards. The mice with leakage showed a decrease only after day 5. The difference in wellness-scores between the groups with- and without leakage was 2 points, increasing during follow-up.

CONCLUSIONS

The model of anastomotic leakage caused by creating an anastomosis with 5 interrupted sutures is feasible. Weight loss and wellness-scores are good predictors of leakage.

Icodextrin and Seprafilm do not interfere with colonic anastomosis in rats

BACKGROUND

Physical barriers and instilled solutions have been studied to prevent intra-abdominal adhesions. However, undesirable side effects of these substances on the healing of intestinal anastomoses may limit their use. This study was designed to compare the effects of antiadhesives on the healing of colonic anastomosis in rats.

METHODS

Sixty female Sprague-Dawley rats were divided into 3 groups of 20. The animals received isotonic saline and 7.5% icodextrin, intraperitoneally after standard left colonic anastomosis. In group 3, Seprafilm was wrapped around the anastomosis and also laid over the abdominal viscera. Half of the animals from each group were killed on postoperative day (POD) 4 and the remaining half on POD 21. Adhesion scoring, bursting pressure and tissue hydroxyproline measurements and histopathological assessment were performed.

RESULTS

Mean hydroxyproline levels were significantly higher in groups receiving icodextrin and Seprafilm compared with the control group, whereas mean bursting pressures were significantly higher in the group that received icodextrin (p < 0.05). Intraperitoneal administration of icodextrin resulted in significant reduction of adhesion formation on POD 21 (p < 0.05).

CONCLUSIONS

Seprafilm does not prevent formation of adhesions as much as icodextrin does, but its effect on the healing of colonic anastomoses is similar.

Avaliação do extrato hidroalcoólico de Aroeira (Schinus terebinthifolius Raddi) no processo de cicatrização de feridas em pele de ratos

OBJETIVO: Avaliar o efeito cicatrizante da administração tópica do extrato hidroalcoólico de aroeira em feridas abertas na região dorsocostal de ratos. MÉTODOS: Utilizou-se 60 ratos Wistar, machos, que tiveram retirado fragmentos de pele com dois centímetros de diâmetro, sob anestesia inalatória com éter etílico. Foram divididos em dois grupos de 30 animais: o grupo aroeira, que recebeu aplicação do extrato hidroalcoólico da planta, e o grupo controle, que recebeu aplicação de solução salina a 0,9%. Cada grupo foi subdividido em 3 com 10 animais cada para serem observados aos sete, 14 ou 21 dias. As áreas das lesões foram analisadas pelo aspecto macroscópico e por planimetria digital. Os espécimes ressecados das feridas foram analisados por microscopia ótica em colorações de hematoxilina-eosina e tricrômio de Masson. RESULTADOS: Os achados macroscópicos demonstraram reepitelização completa mais precoce no grupo controle aos 14 dias. Pela planimetria digital as áreas médias das feridas dos ratos do grupo controle (0,5278 cm²) foram menores que as das feridas dos ratos do grupo aroeira (0,6897 cm²), com significância estatística aos 14 dias de pós-operatório (p=0,036). O estudo histológico demonstrou diferença estatística (p=0,023) em relação às células mononucleares no 14º dia de avaliação, com maior número no grupo aroeira, não havendo diferenças significantes em relação aos outros parâmetros em nenhum dos dias estudados. CONCLUSÃO: O extrato hidroalcoólico de aroeira retardou a reepitelização das feridas da pele dos ratos.

Efeito do extrato hidroalcoólico de Aroeira (Schinus terebinthifolius Raddi) na cicatrização de anastomoses colônicas: estudo experimental em ratos

INTRODUÇÃO: A cicatrização é evento biológico complexo envolvendo inflamação, quimiotaxia, proliferação celular, diferenciação e remodelação. Na medicina popular brasileira, utiliza-se a Aroeira para tratar as mais diversas situações patológicas No Estado do Maranhão - Brasil, a Aroeira é extensivamente utilizada no tratamento de afecções do aparelho respiratório, digestivo e ginecológico. As anastomoses intestinais sempre foram motivo de preocupação para cirurgiões e constituem, até hoje assunto polêmico e repleto de controvérsias. Entre as causas de insucesso da anastomose intestinal destacam-se as fístulas e deiscências. OBJETIVO: Avaliar o efeito do extrato hidroalcoólico de Aroeira (Schinus terebinthifolius Raddi) no processo de cicatrização de anastomoses colônicas em ratos. MÉTODOS: Foram utilizados 40 ratos da linhagem Wistar divididos em dois grupos (grupo Aroeira e grupo controle), aleatoriamente, composto de 20 animais cada, de acordo com o tratamento recebido (extrato da Aroeira ou solução salina a 0,9%) após a anastomose, e subdividiu-se cada grupo em dois subgrupos (C3 e C7 e A3 e A7,) de acordo com o dia de eutanásia (ao 3º e 7º dias). As variáveis utilizadas para mensuração foram: análise macroscópica, microscópica e tensiométrica. As interações entre os grupos foram analisadas pelo teste não-paramétrico de Mann-Whitney. RESULTADOS: Quanto ao grau de adesão, não foi observado diferença significativa entre os grupos Aroeira e controle tanto no 3º quanto no 7º dia. Quando se comparam os subgrupos do ponto de vista microscópico no 3º dia, a diferença entre o grupo que recebeu o extrato da Aroeira e o grupo controle foi significativa nas variáveis congestão (p = 0,005), polimorfonucleares (p = 0,034), mononucleares (p = 0,023), proliferação fibroblástica (p = 0,023) e na fase de cicatrização (p = 0,001). Na análise do 7º dia, todas as variáveis da análise microscópica foram significativas o que levou a 100% dos ratos do grupo Aroeira apresentarem inflamação crônica contra 20% do grupo controle. Em relação ao teste de pressão de ruptura, não houve diferença estatisticamente significante entre os grupos controle e Aroeira. CONCLUSÃO: Observou-se efeito favorável da Aroeira, a nível microscópico, no processo de cicatrização de anastomoses de cólon.

Effects of the intraperitoneal lornoxicam on the formation of intraperitoneal adhesions in rat peritonitis model

BACKGROUND

To investigate the effects of intraperitoneally administered lornoxicam on adhesion formation, bursting pressure, tissue antioxidant levels, morbidity and mortality after ileocolic anastomosis in a rat bacterial peritonitis model.

METHODS

Thirty-six rats were divided into three random groups. Bacterial peritonitis was induced by performing a cecal ligation and puncture, then the cecal was resected and ileocolic anastomosis was performed. Rats of groups 1, 2 and 3 were given 2 mL normal saline, 2 mL lornoxicam, and nothing, respectively. All groups were killed at day 14. Adhesions were scored, and the presence of intra-abdominal abscesses and fistulas were noted. Anastomotic healing was assessed by bursting pressure. Tissue antioxidant levels were tested from left abdominal walls.

RESULTS

One day after cecal ligation and puncture, microbiological examination showed polymicrobial bacterial peritonitis. The rats treated with lornoxicam had significantly lower adhesion scores than did the saline and nothing treated rats (P = 0.007). Bursting pressures of groups were unaffected by the treatment. Tissue antioxidant levels of groups were affected by the treatment. Morbidity and mortality were similar in all groups.

CONCLUSIONS

The present study demonstrated that a single intraperitoneal instillation of lornoxicam in buffer solution at the end of the surgery reduces adhesion formation in rats bacterial peritonitis model. It was also determined that lornoxicam had no negative effect on the healing of intestinal anastomosis, abscess and anastomotic leakage. Use of lornoxicam in peritonitis was effective in decreasing the oxidative stress of tissue during peritonitis.

Efeitos do Tenoxicam sobre a cicatrização da parede abdominal: estudo experimental em ratos

OBJETIVO: Analisar os efeitos do tenoxicam, um antiinflamatório não hormonal, na cicatrização da parede abdominal de ratos. MÉTODOS: Foram utilizados 40 ratos adultos, submetidos à laparotomia mediana e distribuídos, aleatoriamente, em um grupo controle (C), constituído de 20 animais que receberam solução de NaCl a 0,9 %; e um grupo tratado (T), constituído de 20 animais que receberam o tenoxicam. Os animais de cada grupo foram divididos, conforme a data de sacrifício, em subgrupos de 10 animais, denominados C7, C14, T7 e T14. As inscrições 7 e 14 determinaram o sacrifício dos animais no sétimo e décimo quarto dia pós-operatório, respectivamente. As soluções de tenoxicam (1mg/ml) e de NaCl a 0,9% foram administradas no pós-operatório imediato e nos quatro dias seguintes, por via intramuscular, na dose volume de 0,6 ml/kg/dia. No dia do sacrifício, realizou-se a ressecção de dois fragmentos da parede abdominal (1cm x 3cm), que foram utilizados para determinação da concentração de hidroxiprolina e avaliação da força de ruptura. RESULTADOS: Não foram observadas complicações da ferida operatória, incluindo infecção ou deiscência, nos quatro subgrupos de animais. Na análise comparativa dos quatro subgrupos de animais, não foi evidenciada diferença estatisticamente significante no estudo da força de ruptura (p=0,262) e na concentração de hidroxiprolina (p=0,392). CONCLUSÃO: A administração de tenoxicam, por via intramuscular, não interfere na cicatrização da parede abdominal de ratos.

Prevention of peritoneal adhesions by intraperitoneal administration of vitamin E: an experimental study in rats

PURPOSE

Previous studies have shown dietary supplements of vitamin E to reduce the incidence of postoperative peritoneal adhesions. The objective of this study was to show the effect of intramuscular or intraperitoneal administration of vitamin E on peritoneal adhesions.

METHODS

Eighty rats were divided into four groups: Group A (control), Group B (intramuscular vitamin E), Group C (intraperitoneal olive oil, the vehicle/diluent of vitamin E), and Group D (intraperitoneal vitamin E diluted in olive oil). The same experimental method was used in all rats to produce adhesions, consisting of cecal abrasion and ligature of the adjacent parietal peritoneum. The rats were killed at 14 days to assess the adhesions occurring. The results were analyzed using a chi-squared test.

RESULTS

All animals in Groups A, B, and C had substantial adhesions. In Group D, 11 rats had insubstantial adhesions and only 4 had substantial adhesions. There were no significant differences between Groups A, B, and C in terms of percent formation of adhesions. A significant difference was found between Group D (vitamin E plus olive oil by the intraperitoneal route) and each of the experimental groups, A, B, and C (P < 0.0005).

CONCLUSIONS

Our results show that intraperitoneal administration of vitamin E just before closing the laparotomy was effective for reducing adhesion formation. By contrast, the same effect was not achieved after intramuscular administration.

Uso do adesivo de fibrina na anastomose esôfago-esofágica cervical, em cães

OBJETIVO: Estudar os efeitos da associação do adesivo cirúrgico de fibrina à técnica operatória da invaginação submucosa, em anastomoses esofagianas. MÉTODO: Trinta e dois cães submetidos à anastomose esôfago-esofágica foram alocados em dois grupos: I com sutura em doze pontos e II com sutura em quatro pontos e vedação com adesivo de fibrina. Os animais foram avaliados no sétimo e décimo-quarto dias de pós-operatório. Foram analisados: a evolução ponderal, o índice de estenose, a incidência de deiscências e fístulas, a presença de secreções na tela subcutânea, a presença de líquido intersticial, matriz protêica, celularidade, fibroblastos, fibras de colágeno e concentração de hidroxiprolina. RESULTADOS: O índice de estenose foi menor para os animais do grupo I no sétimo dia de observação. Nos animais do grupo II a incidência de deiscências, secreção serosa e purulenta foram signitivamente maiores aos sete e quatorze dias, enquanto a presença de fístulas foi maior no sétimo dia. Quanto à concentração tecidual de hidroxiprolina não houve diferença estatística entre os grupos. Os fibroblastos e fibras de colágeno tiveram presença mais acentuada no grupo II no décimo-quarto dia. Ocorreram quatro óbitos em animais do grupo II. CONCLUSÕES: A anastomose por invaginação submucosa-mucosa com vedação com adesivo de fibrina apresentou piores resultados que a anastomose convencional de doze pontos circunferenciais.

Carboxymethylcellulose coated on visceral face of polypropylene mesh prevents adhesion without impairing wound healing in incisional hernia model in rats

Adhesions between viscera and mesh may result in intestinal obstruction and fistulae formation. Fewer adhesions with sodium carboxymethylcellulose (SCMC)-coated polypropylene mesh (PM) has been reported, but impaired wound healing was the major concern. We investigated the adhesion-prevention effect of SCMC in different concentrations, as coating only on visceral face of PM and its effects on wound healing. A full-thickness abdominal wall defect was created in 28 rats, which were then divided into three groups. In Group I (control), the defect was repaired with PM only; in Group II and Group III, the defects were repaired with 1% and 1.6% SCMC-coated-PM, respectively. All animals were sacrificed at day 30, and histological evaluation and adhesion scoring were done. Animals in the group in which 1.6% SCMC-coated PM was used developed significantly fewer adhesions compared with other animals (P=0.04). Histological evaluation using a semiquantitative scoring system showed no difference between the groups in fibrosis and inflammation scores (P=0.9 and P=0.3, respectively), and thickness of fibrosis on mesh was also similar (P=0.5). SCMC in 1.6% concentration as coating only on the visceral face of PM reduced the incidence and severity of adhesions without impairing wound healing.

Seprafilm® Reduces Adhesions to Polypropylene Mesh and Increases Peritoneal Hydroxyproline

Polypropylene mesh is an effective and widely used material in repairing abdominal wall defects, but it causes dense adhesions when in contact with abdominal viscera directly. As a consequence of this process intestinal obstruction and enterocutaneous fistula may develop. The purpose of the present study was to determine whether Seprafilm®, a bioresorbable translucent membrane, reduces abdominal visceral adhesions to polypropylene mesh and whether Seprafilm® has any effects on peritoneal tissue hydroxyproline levels. Twenty-six adult Wistar rats were used. A full-thickness abdominal wall defect was created and cecal abrasions were created to induce adhesion formation in each animal. All of the abdominal defects were repaired with polypropylene mesh. In addition a Seprafilm® membrane was laid over the abdominal viscera in the Seprafilm® group (n = 13). The abdominal cavity was evaluated for adhesion formation, and peritoneal biopsies were taken for the measurement of tissue hydroxyproline levels at the 14th day. The use of Seprafilm® resulted in significant reduction in the adhesion formation ( P = 0.002) and a significant increase in peritoneal hydroxyproline level ( P < 0.0001). These findings demonstrate that the increase of peritoneal hydroxyproline levels caused by Seprafilm® might play a role on the antiadhesive effects of Seprafilm®.