Pneumoperitoneum Group Research Articles

Preconditioning is a method that may reduce the negative side-effect of pneumoperitoneum

AbstractIncreased intra-abdominal pressure during laparoscopy leads to hypoxia due to reduced blood flow. Aim of our study was to investigate whether preconditioning can reduce this negative effect of the pneumoperitoneum. Fifty female Wistar rats were used, divided into 5 groups. I: Sham operation (Sham), II: conventional pneumoperitoneum (PP), III: transvaginal pneumoperitoneum (TV), IV: preconditioning for 2.5 minutes in two cycles (Pre 2.5), V: preconditioning for 5 minutes (Pre 5). Malondialdehyde (MDA), reduced glutathione (GSH), sulfhydrylgroup (SH-) concentrations, superoxide-dismutase (SOD) and mieloperoxidase (MPO) activity, and anti-apoptotic pathway marker p-AKT level and inflammatory cytokine TNF-α were measured. SOD activity and GSH concentration were decreased in PP and TV groups comparing to Sham and preconditioning groups. MPO activity was decreased also in PP and TV groups comparing to the Sham group but in the preconditioning groups it has remained high. MDA concentration in plasma was increased in PP and TV groups comparing to Sham and preconditioning groups. There was no difference in the case of blood MDA and SH-concentrations between groups. Anti-apoptotic pathway marker p-AKT level was decreased in the TV group comparing to the sham and preconditioning groups. TNF-α level was increased in TV and preconditioning groups compared to the sham group. According to the results preconditioning can reduce negative effects of pneumoperitoneum.

Does pneumoperitoneum increase or decrease the serum levels of interleukin-6?

I read with great interest the recently published article by Schmidt et al. [1] regarding the effect of carbon dioxide pneumoperitoneum. In the summary of their excellent article, they conclude that the interleukin-6 (IL-6) level is significantly higher in the pneumoperitoneum group at 24 h and on day 4. A completely contrasting result can be seen in Fig. 3 (postoperative proinflammatory IL-6 at different postoperative time points; *p 0.05), which shows significantly lower levels of something after 48 h and 4 days than in control animals. This contradiction is quickly solved as we read this article further. Figure 4A (effect of carbon dioxide pneumoperitoneum on liver regeneration as assessed by measurement of regenerating liver mass on days 2 and 4) correctly shows the postoperative proinflammatory IL-6 levels at different postoperative time points. The mixing of these figures is unfortunate.

A novel lifting system for minimally accessed surgery: a prospective comparison between “Laparo-V” gasless and CO2 pneumoperitoneum laparoscopic colorectal surgery

Carbon dioxide (CO(2)) pneumoperitoneum can lead to cardiopulmonary loading and complications. By comparing with conventional CO(2) pneumoperitoneum approach, we introduce a novel Laparo-V lifting system for gasless laparoscopic colorectal surgery. In a prospective study, patients with colonic lesions underwent either Laparo-V gasless (n = 20) or conventional CO(2) pneumoperitoneum (n = 19) laparoscopic colectomy. Twenty patients who underwent open surgery were enrolled as control. Intra-operative monitoring includes blood pressures, heart rate, O(2) saturation, and end-tidal CO(2) (ET-CO(2)). Serum level of interleukin 6 (IL-6), C-reactive protein (CRP), cortisol, and lymphocyte subpopulations (CD4/CD8) were measured repeatedly. Postoperative recovery was indicated by return of bowel function and postoperative hospital stay. Patient characteristics were not different between the three groups. There were three conversions in each laparoscopy group, making conversion rates 15% and 15.7% for Laparo-V and CO(2) pneumoperitoneum groups, respectively. Vital signs remained stable in Laparo-V and open surgery groups; while, elevated ET-CO(2) and heart rate were noted in CO(2) pneumoperitoneum group. Both laparoscopy groups had a significant faster recovery and shorter hospital stay than the open surgery group. Postoperative elevation of IL-6, CRP, and cortisol level was observed in all the three groups, of note, the change was most significant in the open surgery group. Laparo-V gasless laparoscopic approach is feasible in various colorectal procedures. It carries advantages comparable with those of CO(2) pneumoperitoneum; while, the intra-operative hemodynamic was more stable. Therefore, laparoscopic approach using the Laparo-V system could be beneficial to patients with high cardiopulmonary risk and represents an alternative for minimally invasive surgery.

Alterations in portal vein blood pH, hepatic functions, and hepatic histology in a porcine carbon dioxide pneumoperitoneum model

Intra-abdominal high pressure and acidosis by carbon dioxide (CO(2)) pneumoperitoneum is known to affect various organ functions. In this study, changes in liver functions and liver histology were investigated during CO(2) pneumoperitoneum in a large animal model. Fourteen white pigs were anesthetized with intubation and controlled ventilation. The pigs in the pneumoperitoneum group (PG) were exposed to CO(2) pneumoperitoneum at an intra-abdominal pressure of 8 mmHg, and those in the open laparotomy group (OG) were subjected to laparotomy. Hemodynamics were measured and liver function tests were performed in the carotid artery and portal vein, and the liver tissue was histologically examined. The blood pressure, PO(2), PCO(2), and pH in the carotid artery did not significantly differ between the groups. In the PG, blood pressure, PO(2), and PCO(2) in the portal vein were elevated while the pH was low. There were no significant differences in the levels of aminotransferases and lactate between the groups. In the PG, the arterial ketone body ratio (AKBR) was low at 90 min and the ICG retention rate was high at 180 min; these values differed significantly compared to those at 0 min. Histological examination revealed liver congestion in the PG and no significant change in the OG. In the PG, the TUNEL assay revealed positive staining in the area with focal lytic changes. CO(2) pneumoperitoneum at an intra-abdominal pressure of 8 mmHg in a porcine model affected liver functions and caused histological changes in the liver. Although it is uncertain whether these alterations observed in the porcine liver occur in humans as well and whether the alterations are reversible after pneumoperitoneum, it may be necessary to pay attention to liver damage during laparoscopic surgery.

Carbondioxide Pneumoperitoneum Prevents Postoperative Adhesion Formation in a Rat Cecal Abrasion Model

We aimed to investigate the role of the carbon-dioxide (CO(2)) pneumoperitoneum on the prevention of postoperative adhesion formation. Thirty adult male Sprague-Dawley rats (250-350 g) were used for this study. The rats were randomly divided into three groups; in the sham group (n = 10) only, laparotomy was made, in group 2 (n = 10), a pneumoperitoneum was applied for a half-hour duration, followed by laparatomy, and in group 3 (n = 10), pneumoperitoenum time was 2 hours and after a pneumoperitoneum laparotomy was made. A cecal abrasion model was studied for making an adhesion formation. On day 14, all rats were sacrificed and adhesions were scored. Tissue samples from adhesions and peritonea and the cecum wall were examined, both pathologically and biochemically, for tissue hydroxyproline content. There was a statistically significant difference between the control and pneumoperitoneum groups, regarding adhesion numbers and grades (P < 0.001). Cecal tissue hydroxypyroline content level was lower in group 1, and statistically significant differences were observed between groups 1, 2, and 3 regarding hydroxyproline content (P < 0.001). There was a statistically significant difference between the control and pneumoperitoneum groups regarding inflammation (P = 0.002). Pretreatment with the CO(2) pneumoperitoneum had a prophylactic effect on postoperative adhesion formation in this study.

The Comparison between Laparoscopic vs. Open Surgery for Trinitrobenzene Sulfonic Acid-Induced Rat Colitis

Introduction: The etipathogenesis of inflammatory bowel disease (IBD) includes immunologic, genetic and environmental factors. In addition to the colon, frequent extra-intestinal alterations related to pancreas and hepatobiliary system are evaluated in several studies. A minimally invasive approach was applied to the IBD, with the expectation of earlier recovery, fewer postoperative complications. The aim of the study is to compare the effects of laparoscopic and open techniques applied for the surgical treatment of ulcerative colitis on the gastrointestinal system and pancreas, and related systemic consequences. Methods: Colitis was induced in 20 rats by rectal injection of a 5% 0.25mL 10mg/kg TNBS (Sigma, USA) in 50% ethanol. The rats were randomly divided into two groups: rat control, laparotomy was made for two-hour duration (n=10), a pneumoperitoneum was applied for a two-hour duration (n=10). Following the surgical procedures, samples were drawn for biochemical and histopathologic examinations. TNF-?, IL-6, MDA, NO, MPO and PAP levels were evaluated in serum and in tissues of pancreas and colon. Results: Except the MDA and NO levels in colonic tissues, all the parameters indicating the oxidative injury and inflammation were found significantly lower in a pneumoperitoneum group. There was no difference in histopathologic examinations of the both groups. Discussion: The results revealed that despite the pathophysiologic effects of pneumoperitoneum laparoscopic surgery in patients with ulcerative colitis elicited less oxidative damage and inflammation compared to conventional surgery. Regarding the findings we concluded that laparoscopic procedures are safe in patients with IBD but to comment on the effects of pneumoperitoneum related to the longer surgery duration further studies with variable operation times are required.

Effects of carbon dioxide pneumoperitoneum on hepatic function in obstructive jaundice: an experimental study in a rat model

The physiology of the patient during laparoscopy differs from that of open surgery. Both pneumoperitoneum and obstructive jaundice impair the hepatic function, but the combined insult has not been previously examined. In this study, we aimed to investigate the effects of carbon dioxide (CO(2)) pneumoperitoneum on hepatic function in a rat model of obstructive jaundice. Forty-four male Sprague-Dawley rats were divided into four groups: group 1 (n = 10), sham-operated group; group 2 (n = 12), obstructive jaundice group; group 3 (n = 10), CO(2) pneumoperitoneum group; and group 4 (n = 12), obstructive jaundice and CO(2) pneumoperitoneum group. Common bile duct was ligated and divided in the obstructive jaundice groups. After 6 days, a 12-mmHg pneumoperitoneum was induced, maintained for 60 min, and released for 120 min. Blood samples were drawn for the measurement of white blood cell and platelet counts, serum liver enzymes (aspartate aminotransferase [AST], alanine aminotransferase [ALT], total bilirubin). Tissue samples were obtained for analyses of malondialdehyde (MDA), glutathione (GSH), and superoxide dismutase (SOD) levels. We evaluated the degree of liver injury on a grading scale from 0 to 4, histopathologically. Pneumoperitoneum after biliary obstruction resulted in an increase in AST and ALT levels and a decrease in white blood cell and platelet counts. However, changes in liver tissue MDA, GSH, and SOD levels did not correlate with the changes in AST and ALT levels and white blood cell and platelet counts. After sham operation with pneumoperitoneum, the GSH levels in liver homogenate were significantly decreased in the group 3 when compared to the group 2. On the other hand, obstructive jaundice itself caused significant reduction in the SOD activity of liver homogenate in comparison to the group 3. Histopathologically, sinusoidal congestion and vacuolization were more severe in the group 3. Alterations in hepatic function occur in pneumoperitoneum applied jaundiced subjects. However, there were no statistically significant differences between the groups 2 and 4 with regard to white blood cell and platelet counts, serum liver enzymes including AST, ALT, and total bilirubin values, MDA and GSH levels and SOD activity of liver homogenate, and histologic damage. These results indicate that there is no additional risk on liver function associated with pneumoperitoneum performed in obstructive jaundice.

Gasless laparoscopy for benign gynecological diseases using an abdominal wall-lifting system

The use of gasless laparoscopy with an abdominal wall-lifting device for benign gynecological diseases was compared to conventional laparoscopy with CO(2) pneumoperitoneum. From February 2007 to July 2007, 76 women with uterine and/or adnexal benign diseases and candidates for laparoscopic surgery were recruited in this study. Thirty-two women underwent gasless laparoscopic surgery and 44 women underwent pneumoperitoneum laparoscopic surgery. Diverse pathologies, including adnexal cyst, uterine myoma and ectopic pregnancy, were treated successfully with gasless laparoscopic surgery. Compared with the patients in the pneumoperitoneum group, the similar hospital stay (P=0.353) and intraoperative blood loss (P=0.157) were observed. However, the mean operative time in the gasless group was significantly longer than that in the pneumoperitoneum group (P=0.003). No severe intraoperative or postoperative complications were found in either group, except for one case of laparotomic conversion in the pneumoperitoneum group due to dense pelvic adhesions. The total hospital charges were significantly less in the gasless group than in the pneumoperitoneum group (P=0.001). In 38 cases of ovarian cyst resection, the mean operative time in the gasless group remained longer than that in the pneumoperitoneum group (P=0.017). The total hospital charges were also significantly less in the gasless group than in the pneumoperitoneum group (P<0.001). Our preliminary results demonstrated that the laparoscopic procedure using the gasless technique was a safe, effective method to treat benign gynecological diseases. Moreover, it was easy to master. As a minimally invasive treatment, gasless laparoscopic surgery provides a good choice to patients in the undeveloped regions in China without increasing the patients' and the government's burden significantly.

The impact of carbon dioxide pneumoperitoneum on liver regeneration after liver resection in a rat model

In recent years, laparoscopic hepatic resection is performed by an increasing number of surgeons. Despite many advantages of the laparoscopic procedure, it is unclear whether the pneumoperitoneum affects the postoperative liver regeneration after liver resection. The current study aimed to investigate the influence of a carbon dioxide (CO(2)) pneumoperitoneum on liver regeneration in a rat model. In this study, 60 male Wistar rats were subjected to 70% partial hepatic resection. Of these 60 animals, 30 underwent preoperative pneumoperitoneum at 9 mmHg for 60 min. After hepatic resection, the rats were killed at 12, 24, and 48 h, and on days 4 and 7. The outcome parameters were hepatocellular injury (plasma aminotransferases), oxidative stress (plasma malondialdehyde), interleukin-6 (IL-6), and liver regeneration (mitotic index, KI-67; regenerating liver mass). The mitotic index was significantly lower in the pneumoperitoneum group than in the group without pneumoperitoneum at all time points (p < 0.05). In the pneumoperitoneum group, KI-67 was significantly lower on day 4 (p < 0.05). The liver regeneration rate was significantly lower for the animals with pneumoperitoneum on days 2 and 4 (p < 0.05). The postoperative hepatocellular injury was significantly greater after pneumoperitoneum at 12, 24, and 48 h (p < 0.05). Plasma malondialdehyde and IL-6 were significantly higher in the pneumoperitoneum group at 24 h and on day 4 (p < 0.05). This study showed that pneumoperitoneum before extended liver resection impaired postoperative liver regeneration. Oxidative stress reaction and hepatocellular damage was markedly higher after pneumoperitoneum. Further investigations, especially with patients that have impaired liver function, are necessary for clinical consequences to be drawn from these results.

Prophylactic Intraoperative Pneumoperitoneum Decreases Pleural Space Problems after Lower Lobectomy or Bilobectomy of the Lung

Following lower lung lobe resection, prolonged air leaks and residual pleural space are common. We investigated whether an artificially induced prophylactic intraoperative pneumoperitoneum would prevent these complications. Sixty patients who underwent lower lobectomy or bilobectomy were prospectively randomized into 2 groups according to the use of intraoperative pneumoperitoneum. Air was delivered via a catheter placed under the diaphragm in the pneumoperitoneum group. Parameters related to pleural drainage, complications, and hospital stay were compared. No difference between the preoperative characteristics of both groups was present. The mean duration of chest tube drainage was shorter (3.47 +/- 1.04 days vs. 4.87 +/- 1.43 days, P < 0.001) and the mean amount of chest drainage was lower (305.0 +/- 76.9 ml vs. 488.3 +/- 215.2 ml, P < 0.001) in the pneumoperitoneum group. Residual pleural space was observed in 1 pneumoperitoneum patient (3.3 %) and in 8 controls (26.7 %). Pneumoperitoneum patients were discharged 1.1 days earlier on average than the controls. Artificial prophylactic intraoperative pneumoperitoneum is a simple and safe procedure that decreases the postoperative amount of fluid drainage, residual pleural space, duration of chest tube drainage, and hospital stay.

Effect of different intra-abdominal pressure levels on QT dispersion in patients undergoing laparoscopic cholecystectomy

Hemodynamic changes caused by carbon dioxide (CO(2)) insufflation occur frequently in patients who undergo laparoscopic surgery. One indicator of these changes is corrected QT dispersion (QTcd), an index of myocardial function. Prolongation of QTcd has been associated with cardiovascular morbidity and mortality. We compared the effects of high-pressure (15 mmHg) and low-pressure (7 mmHg) CO(2) pneumoperitoneums on the QT interval, the rate-corrected QT interval (QTc), the QT dispersion (QTd), and the corrected QT dispersion (QTcd) during laparoscopic cholecystectomy. Twenty consecutive patients were in a low-pressure pneumoperitoneum group and 32 were in a high-pressure pneumoperitoneum group. A 12-lead electrocardiogram was used to monitor cardiac variables. In all patients, serial electrocardiograms were recorded before anesthesia induction (baseline), immediately after the pneumoperitoneum had been created, every 15 minutes during CO(2) insufflation, and 5 minutes after deflation. Two observers measured the QT intervals independently, and the QTcd was calculated using Bazett's formula. The QT interval and the QTc interval did not change significantly during the study in either group. The QTd and QTcd in the high-pressure pneumoperitoneum group increased significantly during CO(2) insufflation and were significantly higher in the high-pressure pneumoperitoneum group compared with the low-pressure pneumoperitoneum group. Changes caused by CO(2) insufflation were reversible. Statistically significant increases of QTd and QTcd, which are associated with an increased risk of arrhythmias and cardiac events, occur during CO(2) insufflation in both high-pressure and low-pressure pneumoperitoneums. QTd and QTcd were significantly higher in the high-pressure pneumoperitoneum group than they were in the low-pressure pneumoperitoneum group. QT interval changes were not related to anesthetic agents, surgical stress, hypercapnia, or duration of CO(2) insufflation. Increased intra-abdominal pressure may have caused these changes.

Re-Protective Effects of Pre- and Post-Laparoscopy Conditioning, Zinc, Pentoxifylline, and N-acetylcysteine in an Animal Model of Laparoscopy-Induced Ischemia/Reperfusion Injury of the Kidney

Background. Pneumoperitoneum (P) created to facilitate laparoscopy (L) is associated with splanchnic hypoperfusion, ischemia/reperfusion (I/R) injury, and oxidative stress. Aim. This study investigated the effects of pre- and post-laparoscopic conditioning, zinc, pentoxifylline (PTX), and N-acetylcysteine (NAC) on markers of I/R injury in an animal model. Methods. Sprague-Dawley male rats (n = 56, weight range 300–350 g) were randomly placed in one of seven treatment groups. Except for group C (control group who underwent a sham operation without pneumoperitoneum), pneumoperitoneum was created in all using CO2 insufflation under a pressure of 15 mmHg. Group L (laparoscopy) was subjected to 60 min of pneumoperitoneum. Group Lpre (laparoscopic preconditioning plus laparoscopy) was subjected to 5 min of insufflation and 5 min of desufflation followed by 60 min of pneumoperitoneum. Group Lpost (laparoscopy plus laparoscopic post-conditioning) was subjected to 60 min of pneumoperitoneum and 60 min of desufflation followed by 5 min of insufflation and 5 min of desufflation. The laparoscopy plus zinc (LZ), PTX (LP), and NAC (LNAC) groups received a single intraperitoneal injection of zinc (50 mg/kg), pentoxifylline (50 mg/kg), or N-acetylcysteine (150 mg/kg) 5 min before the desufflation period. Animals were sacrificed at the end of the experiments, and kidney samples were tested for malondialdehyde (MDA), catalase (CAT), glutathione peroxidase (GPX), and superoxide dismutase (SOD). Results. MDA levels, as an indicator of oxidative stress in kidney tissue samples, were significantly higher in all pneumoperitoneum groups compared to Group C, except for Group Lpre. The pattern of change in tissue levels of SOD, GPX, and catalase was variable in the different treatment groups. Conclusions. In this animal model of renal ischemia/reperfusion injury, laparoscopy caused renal ischemia as evidenced by elevated markers of tissue ischemia-reperfusion injury. This effect was significantly attenuated by post-laparoscopy conditioning, zinc, pentoxifylline, and N-acetylcysteine, but not by pre-laparoscopy conditioning.

Laparoscopic surgery induced interleukin-6 levels in serum and gut mucosa: implications of peritoneum integrity and gas factors

The peritoneum serves as an integral part of host immunity, and the homeostasis of intraperitoneal environment is held to be beneficial for patient recovery after abdominal surgery. How minimal invasive access to the abdomen by laparoscopy and incisions would alter the intraperitoneal immune response is not fully defined. This study examined the levels of IL-6 in serum and gut mucosa following laparoscopic surgery with reference to the peritoneum integrity and gas factors. BALB/c mice were divided into three groups (ten animals in each group) that underwent different abdominal surgical treatments: laparotomy (open group), laparoscopy with atmospheric air (air group) or carbon dioxide pneumoperitoneum (CO(2) group). A 3-cm incision of the skin and muscle was made in all animals except the peritoneum was left intact in the latter two animal groups in order to cancel out the incisional tissue injury present in laparotomy. Four hours after surgery, serum, and jejunal mucosa were extracted for IL-6 measurement by enzyme-linked immunosorbent assay (ELISA). Open laparotomy resulted in significant elevation of serum IL-6 level when compared to the laparoscopic procedures in the descending order of open > air > CO(2) groups. For the mucosal IL-6 level, both the open and air groups were significantly higher than the CO(2) group. Data from multivariate analysis revealed that breaching or incision of the peritoneum was an important factor for the elevated levels of IL-6 in serum (p < 0.001) and jejunal mucosa (p = 0.032). The present study suggests that laparoscopic techniques to minimize the size of the peritoneal incision as well as exposure to atmospheric air can potentially reduce postoperative stress responses associated with abdominal surgery and prompt early recovery.

Effects of CO2pneumoperitoneum on the abdominal viscera metastasis and peritoneal implantation of gastric cancer cell line

Objective To study the effects of CO2 pneumope ritoneum on the abdominal viscera metastasis and peritoneal implantation of gastric cancer cell line MKN45 during laparoscopic gastric surgery.Methods The gastric cancer cells metastatic model was eslhblished by injecting 1 ml(2×107/ml)human gastric cancer cell line MKN45 susDension into the caecum wall of 60 Balb/C mice.Two weeks later,the Balb/C mice were divided into CO2 pneumoperitoneum group(n=30)and laparotomy group(n=30). All mice were sacrificed 7 weeks later to investigate the abdominal viscera metastasis and peritoneal implantation of gastric cancer cells.Results Twenty-seven rats in CO2 pneumoperitoneum group were induced with tumor,including 8 with troear port implantation and 19 with organ metastasis;26 rats in laparotomy group were induced with tumor,including 7 with tracar port implantation and 19 with abdominal viscera metastasis,and the differences between the two groups had no statistical significance(x2=0.007,0.240,0.202,0.106,0.042,P＞0.05).Conclusions CO2 pneumoperitoneum does not stimulate the metastasis of gastric cancer(cells to peritoneum and abdominal viscera in Balb/C mice.Laparoscopic surgery for gastric cancer is safe and feasible. Key words: CO2 pneumoperitoneum; Gastric cancer; Metastasis

Postoperative Peritoneal Dissemination of Ovarian Cancer Cells is not Promoted by Carbon-dioxide Pneumoperitoneum at Low Intraperitoneal Pressure in a Syngenic Mouse Laparoscopic Model with Controlled Respiratory Support: A Pilot Study

Study Objective To investigate postoperative peritoneal dissemination of ovarian cancer cells in a syngenic mouse model with and without controlled respiratory support (CRS). Design Randomized controlled trial (Canadian Task Force classification I). Setting Academic facility. Subjects Sixty-four female C57BJ6 mice. Interventions Mice were randomly divided into 4 surgical groups: anesthesia alone group; 2 carbon-dioxide pneumoperitoneum groups, 1 with low (2 mm Hg) and 1 with high (8 mm Hg) intraperitoneal pressure (IPP); and finally the laparotomy group. Each of the 4 groups was then subdivided into one group with CRS and the other without. Mouse ovarian cancer cells were injected intraperitoneally just before surgery. Measurements and Main Results A laparotomy was performed to evaluate postoperative peritoneal dissemination of ovarian cancer cells on postoperative day 14. A computerized analysis system was then used to evaluate peritoneal dissemination. In the groups with CRS, the peritoneal dissemination score was significantly higher in the laparotomy and high IPP groups compared with anesthesia alone (p <.0001 vs laparotomy, p <.002 vs high IPP) and low IPP (p <.0002 vs laparotomy, p <.004 vs high IPP) groups. No significant difference was detected between the low IPP and anesthesia alone groups. Conclusion Postoperative peritoneal dissemination of ovarian cancer cells is not promoted by a carbon-dioxide pneumoperitoneum with a low IPP in a mouse model with CRS when assessed on postoperative day 14.

CO 2 Pneumoperitoneum Prolongs Survival in an Animal Model of Peritonitis Compared to Laparotomy

The advantages of laparoscopic surgery have been well documented. However, the impact of pneumoperitoneum on sepsis sequelae is still equivocal. This study aimed to evaluate the effect of CO(2) pneumoperitoneum, applied under different pressures and exposure times, on sepsis cascade and mortality. In 42 New Zealand rabbits, peritonitis was induced by the cecum ligation and puncture model. After 12 h, the animals were randomized in seven groups: a control group, four groups with pneumoperitoneum (10-15 mmHg for 60-180 min), and two groups with laparotomy (for 60 and 180 min). Blood samples were collected before cecum ligation and puncture, 12 h later and 1, 3, and 6 h after pneumoperitoneum desufflation or abdominal trauma closure to evaluate bacteremia, endotoxemia, white blood cells count, C-reactive protein, and procalcitonin levels. Furthermore, the mortality time was recorded in all animals. Bacteremia and endotoxemia were induced in all groups. Endotoxemia levels were significantly more elevated in the group where pneumoperitoneum was performed under 15 mmHg for 180 min compared with all other groups at 1 and 3 h after pneumoperitoneum desufflation (P < 0.05), except when compared with the group where pneumoperitoneum was performed under 10 mmHg for 180 min. White blood cell and C-reactive protein levels showed similar trends for all groups. However, serum procalcitonin reached statistically higher levels (P < 0.05) in groups with laparotomy compared with groups with pneumoperitoneum and with the control group at 6 h. Survival was lower in the laparotomy groups compared with the pneumoperitoneum groups and with the control group (P < 0.05). In the presence of peritonitis, CO(2) pneumoperitoneum applied in clinically standard pressures, even for extended time intervals, reduces the severity of sepsis and prolongs survival.

Influence of artificial pneumoperitoneal media on colon carcinoma cell proliferation in vitro

To evaluate the influence of different pneumoperitoneal media on colon carcinoma LS-174T cell proliferation in vitro. The artificial pneumoperitoneum was established. The proliferation of LS-174T cells was detected by MTT assay and soft agar clone formation assay. Expression of HIF-1alpha and VEGF was examined by immunohistochemistry. Apoptosis of LS-174T cells was analyzed by AO/EB double fluorescein stain and flow cytometry. The growth speed and proliferating capacity of LS-174T cells in CO(2) pneumoperitoneum group[A:0.37 +/- 0.02,formation (32.8 +/- 3.6)%] were significantly higher than those in control group [A:0.33 +/- 0.01,formation (28.4 +/- 2.3)%] and He group [A:0.30 +/- 0.01,formation (23.5 +/- 2.7)%], meanwhile the He group was the lowest (P<0.01). Positive expression of HIF-1alpha and VEGF in CO(2) and He artificial pneumoperitoneum up-regulated significantly as compared to control group(P<0.01), meanwhile the above expression was higher in CO(2) group (P<0.01). The G(0 )/G(1) ratio in CO(2) group was the lowest as compared to control group and He group (P<0.01), and G(0 )/G(1) ratio in He group was higher than that of control group(P<0.01). Aapoptosis rate in He group was the highest as compared with the other two groups(P<0.01). CO(2) pneumoperitoneum has stronger effect on the proliferation of colon carcinoma cell LS-174T as compared to He pneumoperitoneum in vitro.

Major surgical trauma induces proteolysis of insulin-like growth factor binding protein-3 in transgenic mice and is associated with a rapid increase in circulating levels of matrix metalloproteinase-9

The authors previously demonstrated a significant decrease in plasma levels of intact insulin-like growth factor binding protein-3 (IGFBP-3) after major open but not after laparoscopic-assisted surgery in humans. They postulated that this decrease may have an effect on postoperative tumor growth. It also has been shown that plasma levels of matrix metalloproteinase-9 (MMP-9), a protease capable of degrading IGFBP-3, are transiently increased after open colectomy in humans. The authors aimed to develop an animal model that would allow further study of the effect that surgical trauma has on plasma levels IGFBP-3 and MMP-9. In addition, they set out to assess the concentration of MMP-9 in circulating monocytes before and after surgery. The 30 mice included in this study were divided into three groups: sham laparotomy, carbon dioxide (CO2) pneumoperitoneum, and anesthesia control. All mice were IGFBP-3 transgenics (overexpressing human IGFBP-3) on a CD1 background. The mice were anesthetized using ketamine and xylazine. Blood was drawn retroorbitally 48 h before the procedure. The duration of the procedure was 30 min. The animals were killed 24 h postoperatively and blood was drawn. Intact IGFBP-3 levels were measured using a combination of Western blot analysis and enzyme-linked immunoassay (ELISA) at the two time points: before and after the operation. Plasma and peripheral blood mononuclear cell levels of MMP-9 were measured at each time point using zymography. Mononuclear cell lysates were used to determine intracellular MMP-9 levels. Plasma levels of intact IGFBP-3 were significantly lower than preoperative levels after sham laparotomy. A mean decrease of 76.6% was noted (p < 0.05). Zymography demonstrated significantly higher plasma MMP-9-related proteolytic activity than observed preoperatively after sham laparotomy (78.5 vs 42.3 Relative Units [RU]; p < 0.05). In the pneumoperitoneum group, no significant decrease was found between the pre- and postoperative levels of intact IGFBP-3. A nonsignificant increase in MMP-9 was noted after CO2 pneumoperitoneum (38 RU preoperatively vs. 46.4 RU postoperatively; p > 0.05). The anesthesia control group did not demonstrate a significant change in either circulating intact IGFBP-3 levels or MMP-9 levels. Mononuclear intracellular levels of MMP-9 were significantly lower after laparotomy than the preoperative levels (3 vs 37 RU). The postprocedure intracellular levels of MMP-9 were not significantly decreased in the pneumoperitoneum or anesthesia control group. Plasma levels of intact IGFBP-3, a cell growth regulating factor, were found to be decreased significantly after laparotomy. This decrease was not seen after pneumoperitoneum. Depletion of intact IGFBP-3 after laparotomy correlated with a rapid release of MMP-9 from mononuclear cells and an increase in circulating plasma MMP-9 levels. Matrix metalloproteinase-9 may play an important role in IGFBP-3 proteolysis after surgical trauma. Furthermore, circulating mononuclear cells are one source of MMP-9 after surgery. Finally, the model used reproduces events in humans after surgery, and thus should permit further study on the mechanism of IGFBP-3 proteolysis after surgical trauma.

Laparoscopic surgery and the parasympathetic nervous system

Laparoscopic surgery preserves the immune system and has anti-inflammatory properties. CO2 pneumoperitoneum attenuates lipopolysaccharide (LPS)-induced cytokine production and increases survival. We tested the hypothesis that CO2 pneumoperitoneum mediates its immunomodulatory properties via stimulation of the cholinergic pathway. In the first experiment, rats (n = 68) received atropine 1 mg/kg or saline injection 10 min prior to LPS injection and were randomization into four 30-min treatment subgroups: LPS only control, anesthesia control, CO2 pneumoperitoneum, and helium pneumoperitoneum. In a second experiment, rats (n = 40) received atropine 2 mg/kg or saline 10 min prior to randomization into the same four subgroups described previously. In a third experiment, rats (n = 96) received atropine 2 mg/kg or saline 10 min prior to randomization into eight 30-min treatment subgroups followed by LPS injection: LPS only control; anesthesia control; and CO2 or helium pneumoperitoneum at 4, 8, and 12 mmHg. In a fourth experiment, rats (n = 58) were subjected to bilateral subdiaphragmatic truncal vagotomy or sham operation. Two weeks postoperatively, animals were randomized into four 30-min treatment subgroups followed by LPS injection: LPS only control, anesthesia control, CO2 pneumoperitoneum, and helium pneumoperitoneum. Blood samples were collected from all animals 1.5 h after LPS injection, and cytokine levels were determined by enzyme-linked immunosorbent assay. Serum tumor necrosis factor-alpha (TNF-alpha) levels were consistently suppressed among the saline-CO2 pneumoperitoneum groups compared to saline-LPS only control groups (p < 0.05 for all four experiments). All chemically vagotomized animals had significantly reduced TNF-alpha levels compared to their saline-treated counterparts (p < 0.05 for all), except among the CO2 pneumoperitoneum-treated animals. Increasing insufflation pressure with helium eliminated differences (p < 0.05) in TNF-alpha production between saline- and atropine-treated groups but had no effect among CO2 pneumoperitoneum-treated animals. Finally, vagotomy (whether chemical or surgical) independently decreased LPS-stimulated TNF-alpha production in all four experiments. CO2 pneumoperitoneum modulates the immune system independent of the vagus nerve and the cholinergic pathway.

The Effects of Carbon Dioxide Pneumoperitoneum on Tyrosine Hydroxylase Activity

The aim of this study is to investigate the effects of carbon dioxide (CO2) pneumoperitoneum on tyrosine hydroxylase (TH) activity and total protein (TP) levels. Forty male Sprague-Dawley rats were randomized into 10 groups, each consisting of 10 rats. Groups 1 and 2 consisted of anesthesia and sham-operated control rats, respectively. In the study groups, 10 mm Hg (group 3) and 15 mm Hg (group 4) pneumoperitoneum with CO2 were accomplished. At the end of the procedures, the brains and adrenals were removed quickly, and the hypothalamus and adrenal medulla separated, weighed, and homogenized. TH activity and TP levels were determined. The adrenal medulla TP and TH activity levels were decreased consistently and this decrease was significant in the sham and pneumoperitoneum groups compared with the control group (P<0.05). The adrenal medulla TP and TH activity levels were reduced significantly in group 4, as compared with the other groups (P<0.05). Elevation of hypothalamic TH activity in group 4 was significantly higher than in the other groups (P<0.05). These results indicate that CO2 pneumoperitoneum applied with 10 and 15 mm Hg pressure gradually decreases the adrenal medulla TH activity; TH is an indispensable enzyme for the biosynthesis of catecholamines. CO2 pneumoperitoneum with 15 mm Hg pressure significantly elevated hypothalamus TH activity.