Soybean oil prevents peritoneal adhesions ... - Wiley Online Library

Surgical Practice

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doi:10.1111/1744-1633.12120

Original Article

Soybean oil prevents peritoneal adhesions without impairing colonic anastomotic healing Ahmet Dag,1* Tahsin Colak,1 Okay Koc,1 Lokman Ayaz,2 Ulku Comelekoglu3 and Ebru Serinsoz-Pfeiffer4 Departments of 1General Surgery, 3Biophysics and 4Pathology, Mersin University, Mersin and 2Department of Biochemistry, Trakya University, Edirne, Turkey.

Aim: Adhesion formation could potentially result in significant morbidity and mortality. In the present study, we investigated the role of soybean oil in the prevention of peritoneal adhesions and its effect on the anastomotic healing process. Patients and Methods: A total of 40 male Wistar Albino rats were randomly assigned to four groups: group A, adhesion induction method; group B, adhesion induction method with administration of soybean oil; group C, colonic anastomosis method; and group D, colonic anastomosis method with administration of soybean oil. Adhesions were scored on postoperative day 7. Anastomotic healing was assessed by determining anastomotic bursting pressure (ABP), tissue hydroxyproline content and the histopathological examination. The serum malondialdehyde (MDA), nitric oxide (NO) and myeloperoxidase (MPO) levels were determined to evaluate cellular response to injury. Results: The difference in mean values between saline- and soybean oil-treated groups, using both the adhesion method and colonic anastomosis method, were statistically significant (P = 0.0003, P = 0.009). Soybean oil administration resulted in no significant difference in terms of ABP and histopathological scores (P = 0.694 and P = 0.246, respectively). Tissue hydroxyproline content was increased significantly with soybean oil administration (P = 0.001). Mean MDA, NO and MPO levels were significantly decreased in the soybean-administered colonic anastomosis group (P = 0.001, P = 0.001, P = 0.002, and respectively). In the soybean-administered adhesion group, mean MDA, NO and MPO levels were lower than in the control group, but the differences were not significant (P = 0.113, P = 0.958, and P = 0.597, respectively). Conclusion: Soybean oil administration intraperitoneally has been shown to prevent adhesion formation effectively without impairing the colonic anastomotic healing process. Key words:

colonic anastomotic healing, intraperitoneal adhesion, soybean oil.

Introduction Intraabdominal adhesion formations have been a complication from the beginning of modern surgery. They occur after 50–90 per cent of all abdominal surgical interventions, and can cause complications, such as intestinal obstruction, female infertility or chronic abdominal pain.1,2 Several methods have been tried to reduce postoperative adhesions.3–5 Mechanical and viscous solutions are widely used to prevent adhesion formation by separation of the operative surfaces.6–9 An ideal material should be easy to use, last for an appropriate time period to prevent adhesions, be resorbed after an appropriate period and not cause inflammation, which may worsen the anastomosis healing process. Unfortunately, an effec*Author to whom all correspondence should be addressed. Email: [email protected] Received 21 February 2014; accepted 10 February 2015.

© 2015 College of Surgeons of Hong Kong

tive solution to prevent peritoneal adhesion formation has not yet been achieved. Currently-popular materials vary and include forms of films, viscous gels and intraperitoneal solutions. The rationale of these methods include decreasing peritoneal damage or the initial inflammatory response, preventing fibrin formation or increasing fibrinolysis and acting as a barrier to adhesion formation. Several agents can reach this goal, but negative side-effects include bowel anastomosis impairment via a disruption in wound healing. In fact, the presence of adhesions usually makes future surgeries difficult, and could increase the risk of intestinal injury, thus requiring further anastomoses.10,11 Soybean oil is a viscous solution with antioxidant properties, likely due to its high tocopherol content. It has been investigated as an adhesion inhibitor in one article in the current literature, which demonstrated soybean oil to effectively prevent peritoneal adhesion Surgical Practice (2015) 19, 98–105

Soybean oil prevents peritoneal adhesions

formation.12 However, the effects of soybean oil on the anastomosis or anastomotic healing process have not yet been investigated. Therefore, we conducted an experimental study to investigate the effect of soybean oil on peritoneal adhesion formation and the anastomotic healing process.

Methods A total of 40 male Wistar Albino rats weighing 190– 220 g were used for all experiments. All of the rats were fed under the same conditions, with a constant room temperature and 12-h light/dark cycle; they were allowed free access to water and standard laboratory diet. The animals were acclimatized for 1 week before the experiments. After adaptation, the animals were randomly assigned to four groups of equal numbers. The rats were prepared for surgery with an injection of 70 mg/kg ketamine hydrochloride (Ketalar; Eczacibasi–Warner Lambert Ilac, Istanbul, Turkey) and 7 mg/kg xylazine (Rompun; Bayer AG, Leverkusen, Germany). Neither mechanical bowel preparation nor intraoperative bowel irrigation were performed. The surgical procedures were performed under sterile conditions. All surgical procedures were conducted in accordance with the National Institutes of Health Guidelines on the Care and Use of Laboratory Animals, and the study was approved by the Committee for Institutional Animal Care and Usage of our university. The researcher, under strict antiseptic condition, performed all surgical procedures. The 40 rats were distributed into four groups of 10 animals each treated as follows: group a, adhesion induction method and intraperitoneal saline injection; group B, adhesion induction method and intraperitoneal administration of soybean oil; group C, colonic anastomosis method and intraperitoneal administration of saline; and group D, colonic anastomosis method and intraperitoneal administration of soybean oil. All of the animals were fasted for at least 12 h immediately before surgery. After hair removal, the abdomen was cleaned with 1 per cent antiseptic

Table 1. Score 1 2 3 4 5

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povidone–iodine solution, and a 3-cm midline laparotomy was made. In groups A and B, the caecum was exposed and abrased for 10 strokes with moderate pressure using a sterile mesh gauze by the same surgeon. Petechial subserosal haemorrhages developed in all cases. In groups C and D, after laparotomy, the left colon was transected (without resection of a segment) 4 cm proximally to the peritoneal reflection, taking care to preserve the marginal arteries. The same surgeon created end-to-end, single-layer extramucosal anastomoses with eight interrupted 6/0 prolene (Prolene; Ethicon Johnson & Johnson/Ethicon, Istanbul, Turkey). Haemostasis was secured, and any residual blood, even minute, was removed completely. In groups A and C, an intraperitoneal application of 2 mL saline was used, and in groups B and D, 2 mL of 1 per cent soybean oil was injected using sterile syringes into the abdominal cavity before completing laparotomy wound closure to prevent escape of the material outside the peritoneal cavity. No drain was left, and the abdominal wound was closed in two layers with continuous 3/0 silk sutures. The animals were allowed to resume their diets. Body weights and wound infections were observed during the experiment.

Measurement of adhesion formation After 7 days, laparotomies were performed, and the abdominal cavity was inspected through a U-shaped incision. Adhesion formation was scored blindly by two independent observers blinded to the groups. The observers assessed the type, tenacity and extent of adhesion formation and the difficulty of adhesiolysis, beginning from the incision using the adhesion scoring system, as shown in Table 1.13 Total adhesion scores for each animal was the sum of type, tenacity and extent scores of lesions. The mean of the two observers’ score was accepted as the adhesion score for each animal. In the colonic anastomosis group, anastomotic leakage was determined macroscopically.

Adhesion scoring system Type

Tenacity

Extent (per cent)

No adhesions Filmy adhesions Firm adhesions Require sharp dissection to be separated More

– Easily fall apart Require traction Requires sharp dissection

– 1–25 26–50 51–75

More

76–100


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Furthermore, anastomotic healing was determined by measuring the anastomotic bursting pressure (ABP) and tissue hydroxyproline content, and performing histologic examination. In addition, serum malondialdehyde (MDA), nitric oxide (NO) and myeloperoxidase (MPO) levels were determined for the measurement of tissue injury.

Measurement of bursting pressure A colonic segment bordering 2 cm on either side of the anastomosis was removed, and the segment was flushed with saline to remove luminal contents. An eight-gauge silastic catheter was inserted into the proximal side of the colonic segment and tied into position by using 2-0 silk, taking care not to disturb the anastomoses. The distal end was fixed to a pressure transducer, and saline was infused through the catheter by using a syringe pump (62-HF-0267-00; Abbott, Chicago, IL, USA) at a rate of 2 mL per minute. The pressure was monitored with a disposable pressure transducer and recorded with the Hewlett–Packard Biopac MP-100 Acquisition System (version 3.5.7; Hewlett–Packard, Santa Barbara, CA, USA). Peak pressures were documented first as the anastomotic bursting pressures before ruptures were recorded.

Hydroxyproline assay Colonic segments were dissected along the mesenteries, with 10-mm and 2-mm segments carefully excised on either side of the anastomosis. All samples were stored at −20°C until further processing. When brought to room temperature, sample dry weights were recorded, and successively, the amount of hydroxyproline was determined as described previously. Absorbance was read using a Cimadzu spectrophotometer (UV-120-02; Cimadzu, Kyoto, Japan), and the collagen concentration was expressed as micrograms of hydroxyproline per milligrams of dry weight tissue.

Histological examination The anastomotic longitudinal sections were fixed in 10 per cent formalin. After being stained with haematoxylin–eosin, anastomoses were graded histologically in a blinded fashion, using a modified numeric scale according to Ehrlich et al.14 Inflammatory cell infiltration, vascular ingrowth, fibroblast proliferation and collagen deposition were graded as: 0 (absence), 1 (occasional presence), 2 (slightly distributed), 3 (abundance) and 4 (confluence of cells or fibres). © 2015 College of Surgeons of Hong Kong

Lipid peroxide assay MDA levels indicating lipid peroxidation were determined by the thiobarbituric acid reaction. The principle of the method depends on the measurement of the pink colour produced by the interaction of barbituric acid with MDA, elaborated as a result of lipid peroxidation. The coloured reaction 1,1,3,3tetraethoxypropane was used as the primary standard. All biochemical measurements were performed in a blinded fashion.

Analysis of NO levels Serum levels of nitrite and nitrate were measured as oxidized end-products of NO, based on the Griess reaction. Blood samples were obtained via continuous catheterization, and immediately centrifuged at 4000 rpm for 10 min. Serum samples were then stored at −70°C until used for assay. Equal volumes of serum and iso-osmotic potassium phosphate buffer were ultrafiltrated at 4000 rpm for 45 min at room temperature. The ultrafiltrate was collected, and nitrates were quantitatively reduced enzymatically by nitrate reductive (nicotinamide adenine dinucleotide phosphate, flavin adenine dinucleotide) until nitrite was performed N-1-(naphthyl)ethylenediamine dihydrochloride, sulphanilamide and incubation solutions were mixed at a ratio of 1:2 (vol/vol). These mixtures were incubated for 5 min at room temperature in dimmed light, and measured at approximately 540 nm. Sodium nitrite (1 mM) was used as a standard to determine nitrite, and potassium nitrate (80 mM) was used as a standard to determine nitrate–NO colorimetric assay (Roche, Mannheim, Germany).

Measurement of MPO activity MPO is a hem-containing enzyme within the azurophil granules of neutrophils; therefore, MPO activity was measured as a simple quantitative method of detecting the amount of leukosequestration. A tissue specimen of 300 mg was homogenized in 0.02 M ethylenediaminetetraacetic acid (pH 4.7) in a Teflon Potter homogenizer. Homogenates were centrifuged at 20 000 × g for 15 min at + 4°C. After the pellet was rehomogenized in 1.5 mL 0.5 per cent hexadecyltirimethylammonium bromide, prepared in 0.05 M KPO4 (pH 6) buffer, it was recentrifuged at 20 000 × g for 15 min at + 4°C. The determination of the MPO activity of the supernatant was based on the fact that it reduced o-dianisidine. Reduced o-dianizidine was measured at 410 nm using a spectrophotometer. Surgical Practice (2015) 19, 98–105


Statistical analysis

Results None of the rats died during the course of the experimental protocols in any of the treatment groups. There were no wound infections, as assessed by clinical inspection. The weight distribution was homogenous between groups at the beginning of the experiment (P = 0.111). Weight gain was observed in all of the groups, and no significant difference in weight gain between groups was observed (P = 0.248). The mean adhesion score of the animals in group A was 6.5 ± 1.9. The mean adhesion score of the animals in group B (3.4 ± 0.5) was lower than that of group A. The difference in the mean values between groups A and B was statistically significant (P = 0.001). The mean adhesion score of the animals in group C (9.6 ± 0.9) was higher than that of group A, and the difference was statistically significant (P = 0.001). However, the adhesion score of the animals in group D (4.7 ± 2.1) was lower than that of group C, and the difference in the mean values between groups C and D was statistically significant (P = 0.009). Total adhesion scores in all groups are shown in Figure 1. No spontaneous anastomotic leak occurred in any of the treatment groups. The mean ABP in group C was 154.9 ± 77.4, and group D was 146 ± 47. Anastomotic bursting pressures in groups C and D are shown in Figure 2. In this experiment, no significant difference in terms of ABP was found by using soybean oil (P = 0.781). The histopathological healing score confirmed the mechanical resistance. Soybean oil administration did not affect the histopathological score, and no © 2015 College of Surgeons of Hong Kong

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Total adhesion score

** 10 * 8 6 4 2 Group A

Group B

Group C

Group D

Fig. 1. Total adhesion scores in all groups. *P < 0.05 in group A compared with group B. **C compared with D.

Anastomotic bursting pressure (mmHg)

Statistical comparisons were performed using oneway ANOVA and Tukey posthoc tests for weight changes, bursting pressures, MDA, NO and MPO levels and the content of tissue hydroxyproline. Data were expressed as means T standard deviations. Differences in histological grading and adhesion scores were compared with Kruskal–Wallis test, and the Dunn test was performed for multiple comparisons. These data were expressed as medians and 25–75 per cent ranges. Wound infections, anastomotic leakage and diarrhoea were analysed using the Mann–Whitney U-test. On the basis of previous studies, approximately six rats in each group should be calculated to detect an expected 50 per cent reduction in ABP, with an error of 5 per cent and b error of 10 per cent. Factoring in death after the experiment, the sample size was established as 10 rats in each group to provide appropriate statistical power analyses.

101

300 250 200 150 100 50 0 Group C

Fig. 2.

Group D

Anastomotic bursting pressures in groups C and D.

statistical difference was observed between groups C and D (P = 0.246). The tissue hydroxyproline content was 2.03 ± 0.73 in group A, 2.59 ± 0.90 in group B, 2.04 ± 0.71 in group C and 4.05 ± 0.74 in group D. The tissue hydroxyproline content was increased significantly by using soybean oil in group D when compared with group C (P = 0.001). However, the difference between groups A and B in terms of tissue hydroxyproline content was not significant (P = 0.406). Tissue hydroxyproline levels in all groups are shown in Figure 3. In the present study, the serum MDA, NO and MPO levels were determined to evaluate cellular response to injury. The mean MDA levels were 11.1 ± 3.1 in group A, 7.4 ± 3.3 in group B, 13.2 ± 4.1 in group C and 4.3 ± 3.0 in group D. In the soybean-administered adhesion group, the mean MDA was lower than the Surgical Practice (2015) 19, 98–105

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*

5,000

120

** ***

3,000

2,000

80 60 40

1,000 Group A

Group B

Group C

20

Group D

Fig. 3. Tissue hydroxyproline in all groups. Data expressed as mean ± standard deviation. *P < 0.05 in group A compared with group D. **B compared with D. ***C compared with D.

Group A

20,000

Group B

Group C

Group D

Fig. 5. Tissue nitric oxide (NO) in all groups. Data expressed as mean ± standard deviation. *P < 0.05 in group A compared with groups D and C. **C compared with B and D groups.

25,000

0.6 *

*

0.5

15,000

MPO (U/mL)

MDA (nmol/mL)

**

*

100

4,000

NO (nmol/mL)

Hydrxyproline wet tissue (ug/mg)

102

10,000 5,000

0.4 0.3 0.2 0.1

0 Group A

Group B

Group C

Group D

Fig. 4. Malondialdehyde (MDA) levels in all groups. Data expressed as mean ± standard deviation. *P < 0.05 in group A compared with group D.

control group, but the difference was not significant (P = 0.113). However, MDA levels were significantly decreased in the soybean-administered colonic anastomosis group when compared with group C (P = 0.001). MDA levels in all groups are shown in Figure 4. The mean NO was 68.1 ± 21.0 in group A, 64.3 ± 10.7 in group B, 91.3 ± 20.9 in group C and 48.2 ± 8.5 in group D. In the soybean-administered adhesion group, the mean NO was lower than the control group, but the difference was not significant (P = 0.958). Moreover, the mean NO was significantly decreased in the soybean-administered colonic anastomosis group when compared with the untreated colonic anastomosis group (P = 0.001). Tissue NO in all groups are shown in Figure 5. © 2015 College of Surgeons of Hong Kong

0 Group A

Group B

Group C

Group D

Fig. 6. Tissue myeloperoxidase (MPO) in all groups. Data expressed as mean ± standard deviation. *P < 0.05 in group A compared with group D.

The mean MPO levels were 0.36 ± 0.1 in group A, 0.29 ± 0.17 in group B, 0.37 ± 0.7 in group C and 0.21 ± 0.88 in group D. In the soybean-administered adhesion group, the mean MPO was lower than the control group, but the difference was not significant (P = 0.597). Moreover, the mean MPO level was significantly decreased in the soybean-administered colonic anastomosis group when compared with group C (P = 0.002). Tissue MPO in all groups are shown in Figure 6.

Discussion Peritoneal adhesions occur after abdominal surgery, secondary to trauma to the peritoneal cavity, as a result Surgical Practice (2015) 19, 98–105


of the biochemical and cellular response. Peritoneal adhesions can contribute significantly to morbidity by causing complications, such as intestinal obstruction. Several methods, adjuvants and materials have been evaluated to prevent or reduce the formation of postsurgical adhesion in many clinical and animal trials.1–9 Strategies have been proposed with the intent to decrease peritoneal damage or the initial inflammatory response, prevent fibrin formation or collagen deposition, increase fibrinolysis and separate with barriers. Physical barriers, including both mechanical and viscous solutions, are widely used to prevent adhesion formation by limiting tissue apposition during the critical stages of mesothelial repair. Adhesions result from the normal peritoneal wound-healing response, and develop in the first 3–5 days after injury.7,15 With the barrier technique, surgically-traumatized surfaces are kept covered during mesothelial regeneration, thus preventing the adherence of adjacent structures and reducing adhesion formation. Barrier agents exert their effects locally at the site where they have been applied, and have no effect on remote areas in the peritoneal cavity. However, an ideal barrier does not yet exist. Soybean oil is used in many medical research studies for different purposes; however, only one study has examined its potential in preventing postoperative peritoneal adhesions.12 In the present study, we evaluated the effect of soybean oil on peritoneal adhesions, and we found a significant decrease in adhesion formation. In this study, we also found that soybean oil retained fluid in the peritoneal cavity for 7 days, preventing organs and injured peritoneal surfaces from coming in contact with each other. Soybean oil is absorbed slowly from the peritoneal cavity, and could create a mechanical and hydrophobic barrier; this could be one reason for its inhibitory effect on postoperative peritoneal adhesions. The absorption of soybean oil exceeds the duration of mesothelial regeneration. However, there could be multiple reasons to explain our results. Soybean oil has the greatest antioxidant capacity when compared to similar oils, likely due to its high tocopherol content.16 Our study supports this fact, as we showed its antioxidant effect. In the present study, the serum NO, MDA and MPO levels were determined to evaluate cellular response to injury. Both of these parameters were decreased in the soybeanadministered groups, in which the adhesion method was used, without statistical significance. There are three isoforms of nitric oxide synthase (NOS), named according to their activity or the tissue type in which they were first described: neuronal NOS, endothelial NOS and iNOS, which is the primary isoform of NO synthases in normal peritoneal and adhesion fibroblasts.17,18 The increase in iNOS expression levels © 2015 College of Surgeons of Hong Kong

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could be the trigger for the development of postoperative adhesions.19 Decreasing NO levels could occur in the presence of soybean oil, thus ultimately resulting in fewer adhesions. Hypoxia due to trauma and injury to the peritoneal surface could be the initiation trigger for the development of postoperative adhesions through the production of high levels of superoxide. The involvement of oxidative stress in adhesion formation has been well documented. MDA levels represent lipid peroxidation; in the present study, soybean oil decreased lipid peroxidation. MPO activity correlates with the presence of neutrophils in intestinal inflammation, and in the present study, MPO levels decreased with soybean administration. We concluded that a decrease in the levels of MDA, NO and MPO could be a result of the antioxidant effect of soybean oil. The antioxidant properties of soybean oil could decrease the reactive response to peritoneal damage and prevent intraperitoneal adhesion formation. Abdominal surgery for symptomatic adhesions has an increased risk of morbidity, including enterotomy or bowel resection.1,10,11 Adhesion surgery exposes patients to the risk of symptomatic anastomotic leakage, with a mortality rate approaching 20 per cent. An adhesion-reduction material should be indicated for patients needing repeated surgery for adhesions. Ideal adhesion-reduction material should be both noninflammatory, nonreactive and should not interfere with the healing processes of sutures, anastomoses or the incision. As mentioned earlier, soybean oil has been tested for the prevention of postsurgical adhesions in only one study, but that study did not evaluate the effect of soybean oil on anastomotic healing.12 In the present study, we evaluated the effect of soybean oil for both the prevention of adhesions and the colonic anastomotic healing. Adhesions are a common and inevitable consequence of serosal repair, and in the present study, we showed that the adhesion scores of animals in the colonic anastomosis group were significantly higher than those of the adhesion control group. Soybean oil administration significantly decreased adhesion scores. Soybean oil also demonstrated a peritoneal adhesion-prevention quality in the colonic anastomosis group. However, no spontaneous anastomotic leaks occurred in the soybean treatment group. In the present study, anastomotic healing was assessed by determining anastomotic bursting pressure, tissue hydroxyproline content and histological examination, which were accepted as classic parameters for assessing anastomotic healing. These parameters have been used in most studies investigating anastomotic healing, and a great consensus exists on the objectivity of these methods for the determination of anastomotic healing.20,21 In this Surgical Practice (2015) 19, 98–105

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experiment, soybean oil administration resulted in no significant difference in terms of the histopathological healing score and ABP. In addition, tissue hydroxyproline content around the anastomosis was significantly increased with soybean oil administration. Therefore, we suggest that the real effect of soybean oil occurs locally in the peritoneum by acting as a barrier. Hydroxyproline is an amino acid unique to collagen, and its level correlates well with the total amount of collagen. Anastomotic healing is affected with changes in collagen metabolism. In the anastomotic healing process, tissues have the ability to synthesize collagen in a well-oxygenated environment. However, prolonged inflammation could enhance collagen degradation through the release of proteases. The effect of soybean oil antioxidant properties has been shown in this study, and these effects could play a role in maintaining appropriate levels of collagen in the anastomotic region for tissues. Lipid peroxidation caused by free radicals is one of the most important mechanisms of tissue injury.22 In the present study, soybean oil administration resulted in a decrease in MDA and MPO levels. It could be suggested that anastomotic healing might be prevented by the use of soybean oil. A delay in colonic anastomotic healing is in accordance with higher NO levels; this has been demonstrated in previous studies.21,23,24 Higher NO values were attributed to a prolonged inflammatory phase in anastomotic healing. This inflammatory process leads to a delay in anastomotic healing. It is likely that soybean oil acts by reducing the inflammatory process triggered by surgery, through decreasing NO levels. The present study is the first to investigate the effect of soybean oil, both on peritoneal adhesions and also anastomotic healing. This is a study strength, as former studies on peritoneal adhesions do not include the effect the agents have in the anastomotic healing process. If an agent is to be used for preventing peritoneal adhesions, the effect of this agent on the anastomoses must be known. For the most part, fluid and gel barrier strategies that have been previously attempted do not show sufficient efficacy in preventing peritoneal adhesions. Some materials, especially therapies that are delivered with a large volume of fluid, appear to cause oedema. Gels could be designed for one-time use, but fluids are unlikely to be effective as a single treatment. The peritoneum has a strong absorptive capacity, thus low-viscosity fluid and gels are unlikely to be stable long enough in the peritoneum. In the present study, in the seventh day of the operation, we found that soybean oil is still stable, and this day was a critical day for adhesion occurrence. © 2015 College of Surgeons of Hong Kong

The method that we used for producing peritoneal adhesions might be a limitation of the study because we might not achieve the same effect in all rats. We exposed the caecum and abrased for strokes using a sterile mesh gauze, but we did not know whether this was the best model to stimulate peritoneal adhesion. In addition, we used soybean oil intraperitoneally, but we could not guarantee the distribution of the oil equally throughout the peritoneum. Another limitation was that we did not perform any microbiological testing in the present study.

Conclusion Soybean oil administration intraperitoneally has been shown to inhibit adhesion formation effectively, without adverse effects on colonic anastomotic healing. To the best of our knowledge, this is the first report of the effect of soybean oil on the anastomotic wound healing process. Abdominal adhesions bring a vast burden to public health, and cause many expenditures, including hospitalizations, surgeon expenses, laboratory tests, endoscopies, imaging, and work day or productivity losses. If the use of soybean oil is proven to be effective in preventing peritoneal adhesions in humans, this would improve health-care costs and patient outcomes. In the present study, soybean oil could be investigated in surgical practice as a peritoneal adhesion prevention agent. In addition, laparoscopic ventral hernia repairs are being applied widely. This procedure includes mesh administration into the peritoneal surface. Although prolene meshes are inexpensive, their adhesion-increasing properties limit their usefulness. By combining soybean oil with a prolene mesh, these materials could be safely administered to peritoneal surfaces.

Declaration of conflict of interest All authors declare that they have no conflicts of interest.

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