The impact of conventional and laparoscopic colon resection (CO2 or helium) on intraperitoneal adhesion formation in a rat peritonitis model

The "Dark Side" of Pneumoperitoneum and Laparoscopy

Laparoscopic surgery has been one of the most common procedures for abdominal surgery at pediatric age during the last few decades as it has several advantages compared to laparotomy, such as shorter hospital stays, less pain, and better cosmetic results. However, it is associated with both local and systemic modifications. Recent evidence demonstrated that carbon dioxide pneumoperitoneum might be modulated in terms of pressure, duration, temperature, and humidity to mitigate and modulate these changes. The aim of this study is to review the current knowledge about animal and human models investigating pneumoperitoneum-related biological and histological impairment. In particular, pneumoperitoneum is associated with local and systemic inflammation, acidosis, oxidative stress, mesothelium lining abnormalities, and adhesion development. Animal studies reported that an increase in pressure and time and a decrease in humidity and temperature might enhance the rate of comorbidities. However, to date, few studies were conducted on humans; therefore, this research field should be further investigated to confirm in experimental models and humans how to improve laparoscopic procedures in the spirit of minimally invasive surgeries.

Comparison of laparoscopic surgery versus traditional laparotomy for the treatment of emergency patients

Objective

To investigate the clinical efficacy of laparoscopic gastrointestinal emergency surgery and postoperative complications.

Methods

Data for 604 patients undergoing emergency gastrointestinal surgery between January 2013 and December 2018 were analyzed retrospectively. Treatment efficacy and postoperative complications were compared between 300 patients (control group) undergoing traditional laparotomy and 304 patients (observation group) undergoing laparoscopic surgery.

Results

Clinical features were significantly better in the observation group than in the control group, including duration of surgery (59.12 ± 10.31 minutes vs. 70.34 ± 12.83 minutes), intraoperative blood loss (41.21 ± 10.45 mL vs. 61.38 ± 9.97 mL), postoperative pain score (1.25 ± 0.25 points. vs. 5.13 ± 0.43 points), length of hospital stay (5.13 ± 0.24 days vs. 7.05 ± 0.13 days), and time to free activity (13 ± 2.96 hours vs. 22 ± 3.02 hours). The total complication incidence in the observation group was 3.9%, compared with 16% in the control group (16%). No significant differences in direct medical costs were recorded between the observation and control groups.

Conclusions

For patients undergoing emergency gastrointestinal surgery, laparoscopic surgery resulted in better clinical outcomes than traditional laparotomy without incurring additional costs. The potential clinical benefits of emergency laparoscopic gastrointestinal surgery warrant further study.

Effects of carbon dioxide pneumoperitoneum on postoperative adhesion formation and oxidative stress in a rat cecal abrasion model

INTRODUCTION

It is claimed that CO2 pneumoperitoneum (CP) is less adhesiogenic than laparotomy. Our aim in this study was to investigate the local oxidative stress responses and related adhesion formation resulting from exposure to CP.

METHODS

Forty-five rats were randomised into six groups. Group 1 underwent laparotomy only; in group 2, 6 mmHg CP was performed for 60 min; in group 3, the same procedure was carried out using 12 mmHg CP; in group 4, laparotomy and cecal-peritoneal abrasion were performed; in group 5, 6 mmHg CP was performed for 60 min, followed by laparotomy and cecal-peritoneal abrasion; in group 6, the same procedure was carried out using 12 mmHg CP. Groups 1, 2 and 3 were sacrificed immediately and used only for biochemical examination. The other groups were sacrificed on the 14th postoperative day.

RESULTS

The total adhesion scores, thickness, quantity, extent and type of adhesions decreased steadily in groups 4, 5 and 6 (p < 0.05). The median values for neutrophil and monocyte infiltration, and for capillary and fibroblast proliferation decreased steadily in groups 4, 5 and 6 (p < 0.05). CAT, SOD and GSHPx levels decreased significantly in line with increasing pressure in groups 1, 2 and 3. SOD and GSHPx levels were similar in groups 4, 5 and 6, while CAT levels decreased with increasing pressure in groups 4, 5 and 6.

CONCLUSION

It was found that CP is associated with less adhesion formation than laparotomy in the presence of similar antioxidant levels. The reduced adhesion formation is probably caused by a decreased inflammatory response.

Development of a standardized laparoscopic caecum resection model to simulate laparoscopic appendectomy in rats

Background

Laparoscopic appendectomy (LA) has become one of the most common surgical procedures to date. To improve and standardize this technique further, cost-effective and reliable animal models are needed.

Methods

In a pilot study, 30 Wistar rats underwent laparoscopic caecum resection (as rats do not have an appendix vermiformis), to optimize the instrumental and surgical parameters. A subsequent test study was performed in another 30 rats to compare three different techniques for caecum resection and bowel closure.

Results

Bipolar coagulation led to an insufficiency of caecal stump closure in all operated rats (Group 1, n = 10). Endoloop ligation followed by bipolar coagulation and resection (Group 2, n = 10) or resection with a LigaSure™ device (Group 3, n = 10) resulted in sufficient caecal stump closure.

Conclusions

We developed a LA model enabling us to compare three different caecum resection techniques in rats. In conclusion, only endoloop closure followed by bipolar coagulation proved to be a secure and cost-effective surgical approach.

Peritoneal adhesions after laparoscopic gastrointestinal surgery

Although laparoscopy has the potential to reduce peritoneal trauma and post-operative peritoneal adhesion formation, only one randomized controlled trial and a few comparative retrospective clinical studies have addressed this issue. Laparoscopy reduces de novo adhesion formation but has no efficacy in reducing adhesion reformation after adhesiolysis. Moreover, several studies have suggested that the reduction of de novo post-operative adhesions does not seem to have a significant clinical impact. Experimental data in animal models have suggested that CO₂ pneumoperitoneum can cause acute peritoneal inflammation during laparoscopy depending on the insufflation pressure and the surgery duration. Broad peritoneal cavity protection by the insufflation of a low-temperature humidified gas mixture of CO₂, N₂O and O₂ seems to represent the best approach for reducing peritoneal inflammation due to pneumoperitoneum. However, these experimental data have not had a significant impact on the modification of laparoscopic instrumentation. In contrast, surgeons should train themselves to perform laparoscopy quickly, and they should complete their learning curves before testing chemical anti-adhesive agents and anti-adhesion barriers. Chemical anti-adhesive agents have the potential to exert broad peritoneal cavity protection against adhesion formation, but when these agents are used alone, the concentrations needed to prevent adhesions are too high and could cause major post-operative side effects. Anti-adhesion barriers have been used mainly in open surgery, but some clinical data from laparoscopic surgeries are already available. Sprays, gels, and fluid barriers are easier to apply in laparoscopic surgery than solid barriers. Results have been encouraging with solid barriers, spray barriers, and gel barriers, but they have been ambiguous with fluid barriers. Moreover, when barriers have been used alone, the maximum protection against adhesion formation has been no greater than 60%. A recent small, randomized clinical trial suggested that the combination of broad peritoneal cavity protection with local application of a barrier could be almost 100% effective in preventing post-operative adhesion formation. Future studies should confirm the efficacy of this global strategy in preventing adhesion formation after laparoscopy by focusing on clinical end points, such as reduced incidences of bowel obstruction and abdominal pain and increased fertility.

Intraperitoneal adhesions after open or laparoscopic abdominal procedure: an experimental study in the rat

BACKGROUND

Adhesion formation is common after abdominal surgery. The incidence and severity of adhesion formation following open or laparoscopic surgery remain controversial. The role of CO(2) pneumoperitoneum is also widely discussed. This study aimed to compare adhesion formation following peritoneal injury by electrocoagulation performed through open or laparoscopic procedures in a rat model.

MATERIALS AND METHODS

Sixty male rats were randomized to undergo a 1.5-cm peritoneal injury with unipolar cautery under general anesthesia: open surgery (Group A, n=20), laparoscopic surgery with CO(2) pneumoperitoneum (Group B, n=20), and laparoscopic surgery with air pneumoperitoneum (Group C, n=20). Duration of the procedures was fixed at 90 minutes in all groups, and pneumoperitoneum pressure was kept at 10 mm Hg. Ten days later, the animals underwent a secondary laparotomy to score peritoneal adhesions using qualitative and quantitative parameters.

RESULTS

Forty-five rats developed at least one adhesion: 95% in Group A, 83% in Group B, and 55% in Group C (P<.01; Group C versus Group A, P<.01). According to number, thickness, tenacity, vascularization, extent, type, and grading according to the Zühkle classification, no significant difference was observed between Groups A and B. The distribution of adhesions after open surgery was significantly different than after laparoscopic surgery (P<.001). It is interesting that Group C rats developed significantly fewer adhesions at the traumatized site, and their adhesions had less severe qualitative scores compared with those after open surgery (P<.01).

CONCLUSIONS

In this animal model, CO(2) laparoscopic surgery did not decrease the formation of postoperative adhesion, compared with open surgery. The difference with the animals operated on with air pneumoperitoneum emphasizes the role of CO(2) in peritoneal injury leading to adhesion formation.

Impact of pressure and gas type on adhesion formation and biomaterial integration in laparoscopy

BACKGROUND

Laparoscopic mesh repair of inguinal and incisional hernias has been widely adopted. Nevertheless, knowledge about the impact of pneumoperitoneum on mesh integration is rare. The present study investigates pressure and gas-dependent effects of pneumoperitoneum on adhesion formation and biomaterial integration in a standardized animal model.

METHODS

Laparoscopic intraperitoneal onlay mesh implantation (IPOM) was performed in 32 female chinchilla rabbits using CO(2) or helium for pneumoperitoneum. Intra-abdominal pressures were 3 or 6 mmHg. Animals were killed after 21 days, and the abdominal wall was explanted for subsequent histopathological examinations. Adhesions were assessed qualitatively with a scoring system, and the adhesion surface was analyzed semiquantitatively by planimetry. Infiltration of macrophages (CD68), expression of matrix metalloproteinase 13 (MMP-13), and cell proliferation (Ki67) were analyzed at the mesh to host interface by immunohistochemistry. The collagen type I/III ratio was analyzed by cross-polarization microscopy to determine the quality of mesh integration.

RESULTS

After 21 days, perifilamental infiltration with macrophages (CD68) and percentage of proliferating cells (Ki67) were highest after 6 mmHg of CO(2) pneumoperitoneum. The extent of adhesions, as well as the expression of MMP-13 and the collagen type I/III ratio, were similar between groups.

CONCLUSIONS

Our experiments showed no pressure or gas-dependent alterations of adhesion formation and only minor effects on biomaterial integration. Altogether, there is no evidence for a clinically negative effect of CO(2) pneumoperitoneum.

Intra-abdominal adhesion formation: does surgical approach matter? Questionnaire survey of South Asian surgeons and literature review

AIM

The impact of postsurgical intra-abdominal adhesions, which represent a considerable burden for patients and health services, is often underestimated. Various factors influence adhesion formation, including the surgical approach. This study aimed to further understand the condition by investigating surgeons' perceptions of adhesion formation, particularly differences after laparoscopic and open surgery, and by performing a selective literature review.

MATERIALS AND METHODS

South Asian surgeons attending endoscopy symposia in India and in Germany completed Likert-scale-based questionnaires on awareness of adhesion formation and associated consequences in gynecology. MEDLINE and PubMed were searched for articles published in 2000-2010 comparing laparoscopy and laparotomy in relation to adhesion formation. The results of the questionnaire study were then considered in view of findings from this review.

RESULTS

In total, 43.1% (97/225) of questionnaires were completed. Respondents considered that laparoscopy caused fewer adhesions than laparotomy for all gynecological procedures. Although they believed their knowledge of adhesion formation was satisfactory, they widely underestimated the risk, giving estimated rates of 12.5% after laparoscopy and 36.3% after laparotomy. Twenty-eight studies were identified in the review. Most concluded that laparoscopy was less likely to cause adhesions than laparotomy but further statistical analysis was precluded because so many different definitions and classifications of adhesions had been used.

CONCLUSIONS

The risk of adhesion formation was widely underestimated in the study group. Both the questionnaire study and the review concluded that laparoscopy results in less adhesion than laparotomy but further statistical comparison necessitates the development of standard definitions and classifications of adhesions.

Effect of increased abdominal pressure on cytokines (IL1 beta, IL6, TNFalpha), C-reactive protein (CRP), free radicals (NO, MDA), and histology

BACKGROUND

It is generally accepted that proinflammatory mediators, including cytokines, are responsible for the metabolic changes associated with injury. Recent clinical and experimental studies have also shown that the laparoscopic procedures actually produce ischemia-reperfusion injury in the organs by oxygen-derived free radicals. This study aimed to assess the effect of different insufflation pressures and laparotomy on tissue response by comparing the proinflammatory cytokines, C-reactive protein, and serum and tissue levels of oxygen-derived free radicals.

METHODS

Forty mature New Zealand white rabbits were assigned to 4 groups of 10 animals. In groups 1 to 3, CO2 pneumoperitoneum was created using an automatic insufflator to the designated pressure of 10, 15, and 20 mm Hg, respectively. The remaining 10 animals underwent laparotomy using 10 cm midline incision (group 4). Blood samples were collected before (0 min) and at the end of the procedure (60 min). After the collection of last blood samples, all animals were killed and samples from liver and gut were obtained for measurements of tissue malondialdehyde levels and histology.

RESULTS

The proinflammatory cytokine levels were increased significantly in groups 1 to 3, but did not change in the laparotomy group. Serum C-reactive protein levels were elevated in all groups. The comparison of the results between the laparotomy and laparoscopy groups showed that serum interleukin 6 and nitric oxide levels were significantly elevated in relation the intra-abdominal pressure, and serum interleukin 6 and nitric oxide levels peaked in group 3. Tissue malondialdehyde levels were significantly higher in groups 1 and 2 than in groups 3 and 4.

CONCLUSIONS

The findings of our experiment suggest that the elevated intra-abdominal pressure is responsible for ischemia, free radical production, and proinflammatory cytokine response-mediated cell damage during laparoscopic surgery.

Reduced adhesion formation following laparoscopic versus open colorectal surgery

BACKGROUND

Adhesion formation is common after abdominal surgery. This study aimed to compare the extent of adhesion formation following laparoscopic and open colorectal surgery.

METHODS

An observational study was undertaken to identify adhesions in patients undergoing laparoscopy after previous laparoscopic or open colectomy. Adhesions were scored according to a system validated for interobserver (median kappa = 0.80) and intraobserver (kappa = 0.82) agreement. The primary endpoint was the overall adhesion score (0-10); a secondary endpoint was the adhesion score at the main incision site (0-6).

RESULTS

Forty-six patients were recruited (13 laparoscopic and 33 open colectomy). In most patients (n = 29), laparoscopy was performed for tumour staging before liver resection. The median (interquartile range) overall adhesion score was 7 (5-8) in the open group and 0 (0-3) in the laparoscopic group (P < 0.001). A similar difference was found for the main incision score: 6 (4-6) versus 0 (0-0) (P < 0.001).

CONCLUSION

There may be a reduction in adhesion formation following laparoscopic compared with open colectomy, although the small sample size limits this conclusion.

Fibrinolytic responses of human peritoneal fluid in laparoscopic cholecystectomy: a prospective clinical study

BACKGROUND

The reduction in peritoneal fibrinolysis is believed to be the pathogenetic mechanism of adhesion formation. The general conclusion based on previous clinical and experimental studies is that laparoscopic procedures produce less adhesion formation. The association between this beneficial effect of laparoscopic cholecystectomy and peritoneal fibrinolytic changes is not clear. Therefore, the authors aimed to compare the effects of open and laparoscopic cholecystectomy on peritoneal fibrinolysis. For this purpose, fibrinolytic parameters in peritoneal fluid were investigated 24 h after laparoscopic and open cholecystectomies.

METHODS

In a prospective clinical study, peritoneal fluid was sampled via a drain 24 h after laparoscopic (n = 10) and open (n = 9) cholecystectomies. Activities and concentrations of tissue plasminogen activator (tPA), plasminogen activator inhibitor type 1 (PAI-1), and tPA/PAI-1 complex were determined by enzyme-linked immunosorbent assay (ELISA) kits.

RESULTS

In peritoneal fluids, tPA and tPA/PAI-1 complex concentrations were higher in the open cholecystectomy group (p = 0.009 and p < 0.001, respectively), but tPA activity and PAI-1 concentrations did not differ between the groups (p = 0.514 and p = 0.716, respectively).

CONCLUSIONS

Fibrinolytic changes in peritoneal fluid have several similarities in open and laparoscopic cholecystectomies with regard to tPA activity and PAI-1 levels. However, higher tPA levels after the open procedure probably are secondary to more intense tissue handling leading to mesothelial release of tPA.

Laparoscopic resection of curable colon and rectal cancer: an evidence-based review

The initial enthusiastic application of laparoscopic techniques to colorectal surgical procedures was tempered in the early 1990s by reports of tumor implants in the laparoscopic incisions. Substantial evidence has accumulated, including evidence from randomized controlled trials, to support that laparoscopic resection results in oncologic outcomes similar to open resection, when performed by well-trained, experienced surgeons. This review was developed in conjunction with guidelines published by the Society of American Gastrointestinal and Endoscopic Surgeons. Data from the surgical literature concerning laparoscopic resection of curable colorectal cancer was evaluated regarding diagnostic evaluation, preoperative preparation, operative techniques, prevention of tumor implants, and training and experience. Recommendations are accompanied by an assessment of the level of supporting evidence available at the time of the development of the guidelines.

Comparison of the adhesion scoring systems used in animal models and assessment of interobserver reproducibility

Two commonly used adhesion scoring systems were compared and the interobserver variability was assessed in 30 Wistar albino rats. Thirty-five milligrams per kilogram leflunomide was administered orally and intraperitoneally. Two weeks later, adhesion formation was assessed using the two scoring systems. The results showed that the two currently used adhesion scoring systems are subjective and the final results change depending on the observer and the type of the scoring system that has been used.

Inflammatory response of interleukin-1beta and interleukin-6 in septic rats undergoing laparotomy and laparoscopy

It is generally accepted that greater inflammatory response is observed after laparotomy than laparoscopy in animal models. However, in a previous study, we reported there are no significant differences in the systemic response of tumor necrosis factor (TNF)-alpha between the laparotomy and laparoscopy groups in a rat model of endotoxic shock. The present study extends this investigation to the inflammatory response of 2 additional proinflammatory mediators, interleukin (IL)-1beta and IL-6, in septic rats after laparotomy and laparoscopy in the same animal model. Rats received lipopolysaccharide (LPS) intraperitoneally and underwent laparotomy (n = 5), laparoscopy (n = 5), or no surgical intervention (n = 5). A control group received anesthesia only (n = 5). Serum IL-1beta and IL-6 levels were significantly higher at 2, 4, and 8 hours after LPS injection and were equally suppressed in the laparotomy and laparoscopic groups (P < 0.05). Liver IL-1beta mRNA and protein levels were significantly inhibited at 2, 4, and 8 hours in the laparotomy and laparoscopic groups. Liver IL-6 mRNA (2 and 4 hours) and protein (4 hours) levels were also suppressed significantly in both the laparotomy and laparoscopic groups (P < 0.05). There were no significant differences in hepatic levels of mRNA and protein of IL-beta and IL-6 in both the laparotomy and laparoscopic groups. These results extend our previous finding demonstrating the suppression of TNF-alpha in both the laparotomy and laparoscopic groups. The behavior of the markers used in our study demonstrated that the inflammatory response does not differ between laparotomy and laparoscopic surgery in our rat model of endotoxic shock.

Laparoscopic resection of colon Cancer: Consensus of the European Association of Endoscopic Surgery (EAES)

BACKGROUND

The European Association of Endoscopic Surgery (EAES) initiated a consensus development conference on the laparoscopic resection of colon cancer during the annual congress in Lisbon, Portugal, in June 2002.

METHODS

A systematic review of the current literature was combined with the opinions, of experts in the field of colon cancer surgery to formulate evidence-based statements and recommendations on the laparoscopic resection of colon cancer.

RESULTS

Advanced age, obesity, and previous abdominal operations are not considered absolute contraindications for laparoscopic colon cancer surgery. The most common cause for conversion is the presence of bulky or invasive tumors. Laparoscopic operation takes longer to perform than the open counterpart, but the outcome is similar in terms of specimen size and pathological examination. Immediate postoperative morbidity and mortality are comparable for laparoscopic and open colonic cancer surgery. The laparoscopically operated patients had less postoperative pain, better-preserved pulmonary function, earlier restoration of gastrointestinal function, and an earlier discharge from the hospital. The postoperative stress response is lower after laparoscopic colectomy. The incidence of port site metastases is <1%. Survival after laparoscopic resection of colon cancer appears to be at least equal to survival after open resection. The costs of laparoscopic surgery for colon cancer are higher than those for open surgery.

CONCLUSION

Laparoscopic resection of colon cancer is a safe and feasible procedure that improves short-term outcome. Results regarding the long-term survival of patients enrolled in large multicenter trials will determine its role in general surgery.

Stress response to laparoscopic surgery: a review

BACKGROUND

Laparoscopic surgery is associated with reduced surgical trauma, and therefore with a less acute phase response, as compared with open surgery. Impairment of the immune system may enhance surgical infections, port-site metastases, and sepsis. The objectives of this review was to assess immunologic consequences of benign laparoscopic surgery and to highlight controversial aspects.

METHODS

A literature search on stress response to nonmalignant laparoscopic and open surgery was conducted using the MEDLINE and Cochrane databases. Cross-references from the reference list of major articles on the subject were used, as well as manuscripts published between 1993 and 2002.

RESULTS

Local (i.e., peritoneal) immune function is affected by carbon dioxide pneumoperitoneum. The production of tumor necrosis factor and the phagocytotic capacity of peritoneal macrophages are less lowered. The systemic stress response, as determined by delayed-type hypersensitivity response and leukocyte antigen expression on lymphocytes, shows a preservation of immune function after laparoscopic surgery, as compared with conventional surgery.

CONCLUSIONS

Intraperitoneal carbon dioxide insufflation attenuates peritoneal immunity, but laparoscopic surgery is associated with a lower systemic stress response than open surgery.

Fewer adhesions induced by laparoscopic surgery?

BACKGROUND

Laparoscopic surgery has potential theoretical advantages over open surgery in reducing the rate of adhesion formation, but very few comparative studies are available to prove this.

METHODS

A literature search was performed within Medline and Cochrane databases using the key words: adhesion*, adhesiolysis, laparoscop*, laparotomy, open surgery. Further articles were identified from the reference lists of retrieved literature. Both clinical and experimental studies comparing laparoscopy and laparotomy with regard to adhesion formation were retained. In each article, the rates of adhesion formation were identified or deduced for the operative site, access wound site, and distant sites.

RESULTS

Fifteen studies from 1987 to 2001 were identified. Most studies assessed the operative site. Thus, three clinical studies and six experimental ones found fewer adhesions following laparoscopy than laparotomy, while other five experimental studies found similar adhesion rates for the two surgical methods. There were fewer adhesions to trocar wounds than to the laparotomy wounds in seven studies and equal rates of adhesion in one study. The problem of distant adhesions is poorly represented in literature; three studies favored laparoscopy as being followed by fewer adhesions. Because of the important differences between studies with regard to the design, end points, and statistical calculations, a metaanalysis could not be achieved. The conclusion is based on the prevalence of evidence.

CONCLUSIONS

All clinical studies and most of the experimental studies found a reduction of adhesion formation after laparoscopic surgery compared to open surgery.

Reduction, regrowth, and de novo formation of abdominal adhesions after laparoscopic adhesiolysis: a prospective analysis

AIM

A significant reduction of abdominal adhesions at second-look relaparoscopy after adhesiolysis in patients with chronic abdominal pain.

METHODS

368 patients underwent laparoscopic adhesiolysis because of chronic abdominal pain. Regrowth and de novo abdominal adhesions were determined in a qualitative and quantitative way in 24 patients who underwent a second-look re-laparoscopy because of recurrent pain after a mean period of 16 months after the first laparoscopic adhesiolysis. Reduction of incidence, extent, type, and severity of abdominal adhesions between organs and abdominal wall and de novo adhesion formation were determined.

RESULTS

Incidence (40 vs. 26), extent, type, and severity of abdominal adhesions between organs and abdominal wall are significantly reduced after laparoscopic adhesiolysis. After adhesiolysis of adhesions between organs themselves, no significant reduction could be demonstrated (incidence 40 vs. 32). De novo adhesions were present in 5 (5/24) patients.

CONCLUSION

Laparoscopic adhesiolysis results in a significant reduction of adhesions between organs and abdominal wall, despite the occurrence of de novo adhesions in about 20% of the patients.

Combined therapy of allantoin, metronidazole, dexamethasone on the prevention of intra-abdominal adhesion in dogs and its quantitative analysis

AIM: To observe the preventive effects of combined therapy of AMD (allantoin, metronidazolem and dexamethasone in combination) on intra-abdominal adhesion in dogs.

METHODS: 20 dogs of both sexes were used in this study. After laparotomy under anesthesia, 2 cm section of cecal end was clamped and ligated, then 1 cm cecum section was cut and another 1 cm was kept. The cecum stump was closed with purse-string suture. Both parietal and visceral peritonea were stripped for an area of about 3 × 4 cm². Before the skin closure, the animals were divided into two groups randomly. The abdominal cavities in Group AMD (n = 10) were rinsed by 200 mL of AMD solution, and with 50 mL left, whereas the control (n = 10) received the equal volume of normal saline. After 7 d, the degree of intra-abdominal adhesions was evaluated by using the score method of ultrasonography and traditional dissection.

RESULTS: Compared with the control, both the ultrasonography and traditional dissection scores in Group AMD were significantly decreased that marked as 2.0 ± 1.25 vs 3.3 ± 0.82 and 1.91 ± 0.83 vs 3.3 ± 0.82 respectively (P < 0.01).

CONCLUSION: The combined therapy of AMD is an effective way to prevent intra-abdominal adhesion, and ultrasonography is an useful tool to diagnose intra-abdominal adhesion.

Inhibition of tumor necrosis factor-alpha and inducible nitric oxide synthase correlates with the induction of IL-10 in septic rats undergoing laparotomy and laparoscopy

Proinflammatory mediators are implicated in the mediation of host response to surgical stress. Greater inflammatory response has been reported after open surgery than after laparoscopic surgery in animal models. This study investigated the inflammatory response of tumor necrosis factor alpha (TNF) and inducible nitric oxide synthase (iNOS) and the anti-inflammatory response of interleukin (IL)-10 after laparotomy and laparoscopy in a rat endotoxic shock model. Rats received lipopolysaccharide (LPS) intraperitoneally and underwent laparotomy (n = 5), laparoscopy (n = 5), or no surgical intervention (n = 5). A control group received anesthesia only (n = 5). Serum TNF levels peaked at 2 hours after LPS injection and were significantly suppressed in animals undergoing laparotomy and laparoscopy ( < 0.05). Serum IL-10 levels were higher at 2 hours in the laparotomy and laparoscopy groups but were higher only in the laparotomy group at 4 hours after LPS injection ( < 0.05). Hepatic iNOS mRNA and protein were significantly inhibited at 4 and 8 hours in the laparotomy and laparoscopy groups in comparison with the animals receiving LPS only ( < 0.05). The induction of IL-10 correlated with the suppression of TNF and iNOS suggests that IL-10 may play a role in downregulating TNF and iNOS in septic rats undergoing laparotomy and laparoscopy.