Adhesion formation: intraperitoneal catheters in surgical practice.

To compare the adhesion formation, in a rat model, of commercially available materials used as intraperitoneal catheters in clinical practice, pieces of polyurethane, Teflon, silicone, and polyvinyl chloride (PVC) were placed intraperitoneally in 36 female Wistar rats randomly assigned into four groups. Adhesion development was quantitated according to Nair's classification system (NCS). According to NCS, polyurethane showed the least adhesion formation, while the highest scores were found in the PVC group. Comparing the thickness and the firmness of adhesions in the four groups, significant differences were found, with the polyurethane group developing none or filmy and mild adhesions. In contrast, almost all the rats in the Teflon group developed thick and dense adhesions. Thus, polyurethane caused the least adhesion formation among the four materials evaluated, and can be used more extensively for the construction of catheters for prolonged intraperitoneal use.     

Indomethacin decreases carrageenan-induced peritoneal adhesions

For evaluation of a rat intra-abdominal adhesion model, 48 study rats were each given an intraperitoneal injection of 1 ml of 1.5% carrageenan solution and 48 control rats were each given 1 ml of sterile saline solution. Thereafter, 6 control and 6 study rats were killed on days 2, 3, 4, 5, 7, 9, 14, and 21 for assessment of the temporal nature of adhesion formation. No peritoneal reaction or adhesions occurred from saline solution. Carrageenan induced a generalized peritonitis between days 2 and 7. The frequency of adhesions from day 5 onward was 66%. The effects of celiotomy and of systemic indomethacin on carrageenan-induced adhesion formation were then examined. Rats underwent a standardized celiotomy and, on closure of the abdomen, received either an intraperitoneal injection of saline solution (n = 72) or an intraperitoneal injection of carrageenan solution (n = 96). Both groups were then randomized to receive either no indomethacin (IND-0), a single preoperative dose of indomethacin (IND-1), or four perioperative doses of indomethacin (IND-4). Then, 2, 5, 14, and 21 days later, rats from each group were killed, the extent of intraperitoneal adhesions was assessed, and the nature of any adhesions was histologically examined. Celiotomy plus intraperitoneal saline solution produced no adhesions. Celiotomy plus intraperitoneal carrageenan solution (IND-0) significantly increased adhesions to 83%. Preoperatively and perioperatively administered indomethacin significantly decreased the adhesion formation rate to 49%.     

The prevention of postoperative intraperitoneal adhesions by tranilast:N-(3′,4′-dimethoxycinnamoyl)anthranilic acid

The development of postoperative intraperitoneal adhesions continues to be a major concern for surgeons. The purpose of this study was to establish a postoperative adhesion model in rats, and to assess the effectiveness of tranilast (N-(3′,4′-dimethoxycinnamoyl)anthranilic acid) in preventing postoperative adhesion formation. The adhesion model was established in 12 male Donryu rats. This involved two essential factors, drying and bleeding. Another 22 male Donryu rats were used to study the prevention of intraperitoneal adhesions. Tranilast was administered orally pre- and postoperatively. Adhesion strength was evaluated by grading, and basic fibroblast growth factor (bFGF) and transforming growth factor-beta-1 (TGF-β1) concentration were measured. Post-operative intraperitoneal adhesions were seen in all rats, but the adhesions in the tranilast group were significantly less severe than those in the control group. Serum bFGF and TGF-β1 levels in the tranilast group were lower at the time of surgery than those in the control group, and bFGF levels were lower at the endpoint of this study in the tranilast group than in the control group. The TGF-β1 levels at the end-point did not differ between the two groups. These findings demonstrated that tranilast significantly reduced postoperative intraperitoneal adhesion formation.     

Comparative Evaluation of Adhesions to Intraperitoneally Placed Fixation Materials: A Laparoscopic Study in Rats

After laparoscopic ventral hernia repair, the nature of the adhesions to fixation materials or to mesh had not been clarified. We examined adhesion formation specific to the fixation material in rats. We designed an experimental laparoscopy setup, and placed four intraperitoneal fixation materials on the peritoneum of rats without a mesh graft. Another group of researchers documented the incidence and intensity of postoperative adhesion formation. The adhesion scores for the nickel-titanium anchor were significantly greater than those for polylactic acid (p = 0.004), a titanium tacker (p < 0.0001), and fibrin glue (p < 0.0001). No adhesions occurred in the fibrin glue group. Fibrin glue is the preferred fixation material because it produced no postoperative adhesions. The nickel-titanium anchor produced heavy adhesions but may be applicable for recurrent hernia cases and in patients with thin abdominal walls.     

Surgical glove powder and intraperitoneal adhesion formation. An appeal for the use of powder-free surgical gloves.

Intraperitoneal adhesion formation is a major cause of infertility and/or intestinal obstruction. Among the many well-known aetiological factors responsible for peritoneal inflammatory reaction is surgical glove powder; for example, cornstarch powder. A study was undertaken on 30 rats to determine whether cornstarch powder caused intraperitoneal adhesions. The rats were randomised into two groups under laboratory conditions. Laparotomies were performed on all the rats and trauma inflicted to the right uterine horn. The study group received cornstarch powder suspended in normal physiological salt solution intraperitoneally, and the control group received only normal physiological salt solution. Peritoneal adhesions were evaluated after 2 weeks and statistically analysed with a t-test and 95% confidence intervals. The study group showed a statistically significantly higher incidence of intraperitoneal adhesions (P = 0.0003). It is concluded that cornstarch, as used on surgical gloves, caused peritoneal adhesions and should therefore be removed before surgery. Powder-free gloves are more suitable for preventing adhesion formation.     

Prevention of Postoperative Peritoneal Adhesions by Administration of Estrogen

Aim: Postoperative abdominal adhesions represent one of the most common causes of intestinal obstruction in surgical patients. In this study, the effects of intraperitoneal administration of estrogen on the development of postoperative intraabdominal adhesions and peritoneal leucocytes in a rat adhesion model were investigated. Methods: Sixty Wistar albino rats were divided into three groups. Group 1 (control group) had their abdomen closed after surgery without administration of any material or drug. Group 2 (saline group) received 2 ml of 0.9% NaCl, and group 3 (estrogen group) animals received a single intraperitoneal dose of 2 cc (1 mg) estrogen (Estradiol propionate, 50.000U, Akrofilline®, Biofarma, Turkey). All the groups were exposed to the same adhesion-creating procedure (Swolin K. Experimental studies on the prevention of intra-abdominal adhesions. Studies on rats with an emulsion of lipid and prednisolone. Acta Obstet Gynecol Scand. 1966;45:473–498.). After 7–42 days, all animals were sacrificed. Adhesions were scored and peritoneal leucocytes were counted. Results: The adhesion formation and peritoneal leucocyte count of the estrogen group were significantly less than the control and saline groups and a statistically significant difference was determined in comparison of those groups (p <. 05). Conclusion: We concluded that intraperitoneal estrogen decreases the incidence of postoperative intraabdominal adhesion formation in rat adhesion model.     

Increased postoperative peritoneal adhesion formation after the treatment of experimental peritonitis with chlorhexidine

Background and aims Chlorhexidine is known as a substance that produces adhesions. However, in an experimental model of peritoneal injury, lavage with chlorhexidine and saline solutions produced a similar number of adhesions. This study was designed to test the hypothesis that chlorhexidine gluconate 0.05% solution used for the treatment of peritonitis increases formation of postoperative peritoneal adhesions as compared to standard lavage with saline solution.Material and methods Forty Wistar rats were randomly allocated to gastric or faecal peritonitis groups. In each group rats were further randomly subdivided into saline or chlorhexidine peritoneal lavage groups. After 30 days the rats were killed and intraperitoneal adhesions were evaluated by adhesion score and grading.Results Adhesion scores were statistically significantly different between saline and chlorhexidine groups in both gastric and faecal peritonitis models. In the faecal peritonitis chlorhexidine group a 20% small bowel intussusception rate was observed, while there were no such complications in the other study groups. The conglomerate of organs formed by dense adhesions was present in 60% of cases when gastric peritonitis was lavaged by chlorhexidine and in only 10% when saline solution was used (P<0.05). Neither chlorhexidine nor saline solutions have caused such dense adhesions in faecal peritonitis.Conclusion Peritoneal lavage with chlorhexidine gluconate 0.05% solution in the treatment of experimental peritonitis results in increased adhesion formation.     

Experimental evaluation of intra-abdominal adhesions comparing two different intraperitoneal meshes and the effect of a natural anti-inflammatory product on their formation

Purpose:In laparoscopic incisional hernia repair, meshes with a tissue-separating barrier are positioned intraperitoneally. Despite this property, the close contact between mesh and viscera involves a risk of adhesion formation. Some natural products, such as red propolis (RP), could reduce these adhesions owing to their anti-inflammatory properties. This study aimed to compare two different intraperitoneal meshes with respect to their characteristics of adhesion formation, histological findings and evaluate the role of RP in the development of these adhesions.Methods:40 Wistar rats received placement of two different meshes (Symbotex and Dynamesh IPOM) on peritoneum. The animals were divided into two groups: control group (mesh) and treatment group (mesh and RP). After 7 and 14 days, 20 animals of each group underwent midline laparotomy to determine the adhesions and histological characteristics.Results:Out of the 40 animals, there were two deaths in the test group and two in the control group. All animals in both groups developed adherence to the mesh. At postoperative day (POD) 7, two Symbotex meshes presented firm adhesions and at POD 14, two Dynamesh meshes had firm adhesions as well. The comparison between the meshes under the effect of RP in relation to the control group showed no statistical difference.Conclusions:Both meshes showed intraperitoneal adhesions in all evaluated samples with similar results on the characteristics of adhesions. RP showed no effect on the incidence or gradation of intraperitoneal adhesions with the mesh.Key words: Surgical Mesh, Hernia, Rats     

An experimental study evaluating the effect of Mitomycin C on the prevention of postoperative intraabdominal adhesions

BACKGROUND: Fibroblast proliferation is one of the well-known mechanisms for postoperative intraabdominal adhesion formation. Inhibition of fibroblast proliferation is an attractive field of investigation in the prevention of adhesions. Mitomycin C (MMC) is a cytotoxic agent that alkylates and crosslinks DNA and also inhibits fibroblast proliferation up to a few weeks. We aimed to determine the effect of MMC on the prevention of adhesions. MATERIALS AND METHODS: Generation of adhesions in rats by brushing a 1-cm(2) area of the cecum and the peritoneum on the right side of the abdominal wall was followed by intraperitoneal administration of saline, 1 mg/kg MMC, and 0.5 mg/kg MMC in saline. After 45 days, formation of adhesions was graded. RESULTS: The average adhesion scores of the control, and MMC (1 mg/kg), MMC (0.5 mg/kg) groups were 3.2 +/- 0.7, 0.8 +/- 0.6, and 0.7 +/- 0.8, respectively. Adhesion scores of the two MMC-treated groups were significantly lower than that of the control group (P < 0.001). There was no difference between the two MMC groups (P > 0.05). No side effect of MMC was observed. CONCLUSION: MMC was found to be very effective in the prevention of postoperative intraabdominal adhesions.     

Noxytiolin and peritoneal adhesion formation.

Clinical and experimental studies have suggested that intraperitoneal noxytiolin prevents adhesion formation. A reliable experimental animal model was therefore established and the effect of noxytiolin on adhesion formation was evaluated in a controlled trial using 80 rats. All 40 rats given Ringer solution developed adhesions, whereas in 7 out of 40 given noxytiolin no adhesions were found (P less than 0-02). Noxytiolin reduced both the total and the mean number of adhesions formed (P less than 0-2) and their mean length of attachment (P less than 0-05). The anti-adhesive effect of noxytiolin may be due to its anticoagulant, cytotoxic or antibacterial properties.     

Phosphatidylcholine prevents postoperative peritoneal adhesions: an experimental study in the rat

Phosphatidylcholine (PC) is the main constituent of the surface-active material coating peritoneal mesothelium. It may prevent postoperative adhesion formation through production of a lubricant film on mesothelial defects. We therefore examined the effect of its soluble form on surgically induced intraabdominal adhesions in rats. The adhesions were induced at laparotomy by any of four different operative models. PC was administered intraperitoneally (20 mg/rat) or intravenously (20 mg/rat or 50 mg/rat) at the end of the operation and on the second and third postoperative day. It was found that the degree of postoperative adhesion formation was significantly reduced by the intraperitoneal injection of PC in all 4 models. In contrast, no effect was achieved by the intravenous injection of PC, not even at a very high dose level. Our results suggest that soluble PC administered intraperitoneally might be a potent adjunct in postoperative adhesion prevention.     

Fibrin glue inhibits intra-abdominal adhesion formation

To determine the effect of fibrin glue on intra-abdominal adhesion formation, 45 rats were randomized to three groups. Each animal received two adhesion models. Group 1 received no further treatment. Groups 2 and 3 had the adhesion models covered with fibrinogen from fresh frozen plasma (1.77 g/L) and cryoprecipitate (23.6 g/L), respectively. In group 1, 13 of 15 rats had high-grade adhesions in both models. In group 2, high-grade adhesions were noted in nine of 15 rats in model 1 and in 12 of 15 rats in model 2. In group 3, however, high-grade adhesions were seen in only three of 15 rats in model 1, with 11 rats having no adhesions, and in only two of 15 rats in model 2. Histologic analysis suggested accelerated healing in group 3. We conclude that (1) fibrin glue inhibits intra-abdominal adhesion formation in rats, (2) the inhibitory action is dependent on the fibrinogen concentration of the fibrin glue, and (3) adhesions are reduced by fibrin glue regardless of whether the peritoneal defect is closed.     

The Preventive Effect of Rofecoxib in Postoperative Intraperitoneal Adhesions

Background: Previous studies showed that nonsteroidal anti-inflammatory (NSAi) drugs suppressed prostaglandin synthesis and were able to prevent adhesion formation following surgical trauma to the peritoneum. The selective suppression innammatory cascade may prevent adhesion formation. Therefore, we planned this study to experimentally evaluate the effects of Rofecoxib, the selective cyclo-oxygcnase-2 inhibitor, in postoperative intraperitoneal adhesions in an animal model.

Methods: Male Sprague-Dawley rats were divided into three groups of 10. All rats underwent midline laparotomy under ketamine anaesthesia (25 mg/kg im). In group 1 (n = 10), the sham operation group (SG) ; abdominal walls were closed without any process after 2 minutes. In Group 2 (n = 10), the control group (CG) ; standard serosal damage was constituted and the abdominal wall was closed. In group 3 (n = 10), the COX-2 group (COXG), after serosal damage, the abdominal wall was closed. A 12 mg/kg/day dose of was given orally to the rats during one week. On the 7th postoperative day, all rats were sacrificed and intra-abdominal adhesions were evaluated both macroscopically and microscopically.

Results: Macroscopically, no serious adhesion formations were seen in the SG. Multiple adhesion format ions of the CG were significantly more than those of the SG (p < 0.0001). It was determined that adhesions of the COXG diminished (p < 0.0001) when macromorphological adhesion scale results of the COXG were compared with those of the CG. The adhesion scores of the CG were compared microscopically with those of the COXG and granulation tissue formation and fibrosis in the COXG were found to be significantly less than those of the CG (respecti vely p = 0.002, p < 0.0001).

Conclusions: We were of the opinion that Rofecoxib, the selective cyclo-oxygenase inhibitor, was effective in the prevention of postoperative peritoneal adhesions.     

Methylene blue prevents surgery-induced peritoneal adhesions but impairs the early phase of anastomotic wound healing.

OBJECTIVES: Adhesion formation continues to be an important problem in gastrointestinal surgery. In recent years, methylene blue (MB) has been reported to be an effective agent for preventing peritoneal adhesions. However, its effects on the wound healing process are unknown. In the present study, we investigated the effects of MB on the early and late phases of anastomotic wound healing and on adhesion formation. METHODS: We randomly categorized 92 rats into 2 groups in bursting pressure measurements and 50 rats into 3 groups in the adhesion model. We divided the animals into saline-treated (n = 46) or MB-treated (n = 46) groups. Bursting pressures of the anastomoses were measured on postoperative days 3 and 7. In biochemical studies, tissue hydroxyproline levels, total nitrite/nitrate levels and nitric oxide synthase activity were measured on postoperative days 3 and 7. In the adhesion model, we randomly categorized rats into sham (n = 10), saline-treated (n = 20) and MB-treated (n = 20) groups, and the formation of intraperitoneal adhesions was scored on postoperative day 14. We compared the measurement of bursting pressure and biochemical measurements of tissue hydroxyproline levels, total nitrite/nitrate levels and nitric oxide synthase activity. Histopathological findings of specimens were presented. RESULTS: During the early phase of wound healing (postoperative day 3), bursting pressures, tissue hydroxyproline, total nitrite/nitrate levels and nitric oxide synthase activity in the MB-treated group were significantly lower than those of the saline-treated group. On postoperative day 7, there was no significant difference in these parameters between MB and saline-treated groups. In the adhesion model, MB caused a significant reduction in the formation of peritoneal adhesions. CONCLUSION: MB prevents peritoneal adhesions but causes a significant impairment of anastomotic bursting pressure during the early phase of the wound healing process by its transient inhibitory effect on the nitric oxide pathway.     

Influence of the platelet-activating factor receptor antagonist BB-882 on intra-abdominal adhesion formation in rats

Postoperative intra-abdominal adhesion formation is a major clinical problem. We aimed to examine the preventive effect of treatment with the platelet-activating factor (PAF) antagonist (lexipafant, BB-882) on experimentally induced intra-abdominal adhesion formation in rats. Twenty male Sprague-Dawley rats weighing 250 and 290 g were studied. Generation of adhesions in rats by brushing a 1-cm(2) area of the cecum and the peritoneum on the right side of the abdominal wall was followed by intra-abdominal administration of saline and 5 mg/kg in a volume of 0.2 ml PAF receptor antagonist BB-882. After 45 days, formation of adhesions was graded and histological evaluation was processed. The severity of adhesions was significantly less in the BB-882 group than in the control group (p < 0.001, p < 0.05). The average adhesion scores in the control and BB-882 groups were 3.2 +/- 0.6 and 0.6 +/- 0.6, respectively, and the difference between both groups was found to be significant (p < 0.0001). The number of polymorphonuclear leukocytes and fibrotic areas was significantly decreased in the BB-882 group when compared to the control group (p < 0.001, p < 0.002). In conclusion, this study confirms the efficacy of BB-882 in the prevention of postoperative intra-abdominal adhesions in a rat model.     

Effect of nitric oxide on postoperative adhesion formation

Peritoneal adhesions continue to be a significant cause of postoperative complications. The purpose of the present study was to investigate the effect of nitric oxide in preventing postoperative adhesion formation in rats. Three randomized groups of Sprague-Dawley rats were subjected to a standardized lesion by cecal abrasion and parietal peritoneal defect. 0.9% NaCl (control, group 1), L-arginine (300 mg/kg, group 2) and Nomega-nitro arginine methyl ester (L-NAME; 25 mg/kg, group 3) were administered intraperitoneally before abdominal closure and during 3 consecutive days after surgery. Two weeks after surgery, a relaparotomy was performed and the extent of adhesion formation was determined. In groups 1 and 3 heavy adhesions were detected. In the L-arginine group, adhesion formation was significantly less than in the other groups (p < 0.05). This study showed that L-arginine reduced adhesion formation.     

Preventing recurrent postoperative adhesions: an experimental study in rats

A peritoneal lavage model, cyclic intraperitoneal lavage (CIPL), and other adhesion preventing methods with and without fibrinolytic agents were compared to a control group without treatment in an animal study. The adhesion-preventing effect was evaluated at the site of a standardized peritoneal defect (free peritoneal grafting, P) and at the laparotomy wound (L) of 60 rats (12 escape) after surgical lysis of primary adhesions during relaparotomy In five test groups with different treatments and in a control group without treatment recurrent adhesions were investigated during relaparotomy according to an adhesion grading scale with increasing severity (O-III). In the control group only severe adhesions grade II and III were observed. The five test groups showed different distributions of grade 0-II adhesions: compared to the control group a significant difference of the preventing effect was seen after CIPL with 1.36% glucose solution (as used for peritoneal dialysis) and after CIPL with Ringer's solution at the sites P and L, after a one-time irrigation with Ringer's solution only at the peritoneal graft P. Fibrinolytic agents used in CIPL or as single dose application failed to show an improvement compared to the control group.     

Comparison of Ligasure, SurgRx, and suture techniques in intra-abdominal adhesions that occur after liver resection in rats: an experimental study

Mechanical trauma, thermal injury, tissue ischemia during the operation, postoperative infections, and foreign body reactions are important factors for adhesion formation. Bleeding and bile leakage after liver resections can also cause intra-abdominal adhesions. We aimed to evaluate the intra-abdominal adhesions after liver resection in rats using Ligasure and SurgRx. Twenty-seven Sprague-Dawley rats were used in the study. Three random groups were formed. Two liver lobes were resected from the middle using sutures in group A, Ligasure in group B, and SurgRx in group C. Relaparotomy was performed at postoperative day 7 to evaluate intra-abdominal adhesion formation. Adhesion formation was significantly lower in the SurgRx group compared with the suture and Ligasure groups. SurgRx and Ligasure provide effective hemostasis in liver resection without leaving foreign bodies such as clips and knots behind. SurgRx was superior to suture and Ligasure techniques in terms of adhesion formation in our model.     

Comparison of antiadhesive treatments using an objective rat model

Intraperitoneal adhesions are a significant problem (increased morbidity, mortality, and cost) for patients undergoing abdominal procedures. Although a variety of approaches (e.g., fibrinolytic agents, anti-inflammatory drugs, or barrier/separation methods) have been used with some success in preventing adhesions, a comparison of these different modalities has yet to be performed in a model that objectively measures intraperitoneal adhesion formation. Our objectives were to establish an objective, reproducible model of intraperitoneal adhesion formation and to establish efficacy of different treatment modalities in decreasing the strength and extent of intraperitoneal adhesions. In this two-part study, a rat model establishing an objective measure of both the strength and extent of intraperitoneal adhesions was used to compare different treatment modalities. Fibrinolytic agents [recombinant tissue plasminogen activator (rtPA), streptokinase, and urokinase], anti-inflammatory drugs (dexamethasone and tolmetin sodium), and barrier methods [sodium carboxymethylcellulose (CMC), and sodium hyaluronate] and a control group were compared in the first phase. In the second phase, the two most successful agents (rtPA, CMC) were compared both alone and in combination against a commercially available barrier agent (Seprafilm) and a control group. In the first phase of the study, rtPA was the only agent that had a statistically significant effect in decreasing the strength of adhesions. CMC was the only agent that demonstrated a decrease in the extent of adhesions, and the difference tended toward significance. In the second phase, the combination of rtPA and CMC showed a significant decrease in both the strength and extent of adhesions when compared with those of the control group. This decrease was also observed in the group treated with Seprafilm, which showed no difference from the rtPA + CMC group. We conclude that, in this reproducible adhesion model, only the combination of rtPA + CMC and Seprafilm significantly reduced both the strength and the extent of intraperitoneal adhesions.     

Effects of different pulmonary surfactants in the prevention of postoperative intraabdominal adhesion formation

BackgroundAfter abdominal surgery, the formation of postoperative adhesion is a serious problem. The aim of the study is to evaluate the efficacy of 2 different pulmonary surfactants, poractant and beractant, on adhesion prevention in an experimental model.Materials and MethodsAn experimental intraabdominal adhesion model was created in 18 adult female rats by cecal abrasion. The rats were randomly assigned to 3 groups. Group I received no further treatment, whereas groups II and III received intraperitoneal poractant and beractant, respectively, before closing the incision. On the 15th postoperative day, all rats underwent relaparotomy, intraabdominal adhesions were scored macroscopically according to Canbaz scoring system, and the cecum in each animal was evaluated microscopically.ResultsThe median adhesion scores of group II and III rats were significantly lower when compared with group I (P = .02). Group III had a lower median adhesion score than did group II, but this did not reach significance (P > .05).ConclusionThese observations suggest that intraperitoneal instillation of both pulmonary surfactants is associated with lower adhesion scores, higher adhesion-free cases, and improved histologic findings.