Sequential periods of preconditioning decrease laparoscopy-related elevations in hepatic TNF-alpha and IL-6 levels in rats

What is the ideal preconditioning time to reduce laparoscopic-induced oxidative stress?

Introduction

Ischaemic preconditioning is the most effective method for the prevention of ischaemic-reperfusion injury; however, no study has examined the question of the ideal time for ischaemic preconditioning.

Patients and Methods

The patients were divided into five groups, each group including of 20 patients. The precondition was applied as 1, 5, 10 and 15 min in Groups I, II, III and IV and Group V was the control group. Repeated blood samples were taken to measure the total antioxidant status (TAS), total oxidant status and oxidative stress index (OSI) values, just before insufflation, at the end of the operation and at 6 and 24 h of the post-operative period.

Results

A significant difference was observed between the TAS values at the end of the operation and at the sixth post-operative time of the four groups (P = 0.001, 0.000, 0.001, 0.019 and 0.033, respectively). Furthermore, a significant difference was observed between TAS values at the post-operative 24th h of Group III and Group V, and also a significant difference was observed between the OSI values at the post-operative 6th h of Groups III and V.

Conclusion

The low OSI and TAS values may interpret as a low degree of oxidative damage. The OSI values at the post-operative 6 h of Groups I and II were lower than those of other groups. We accept this result as low oxidative damage.

Attenuation of Oxidative Stress by Ischemic Preconditioning in an Experimental Model of Intraabdominal Hypertension

PURPOSE

Increased intra-abdominal pressure, as used in laparoscopic surgery or seen in intraabdominal hypertension (IAH), is associated with tissue ischemia and oxidative stress. Ischemic preconditioning (IP) is a method successfully used in liver and transplant surgery, in order to attenuate the detrimental effects of ischemia and reperfusion. In this experimental study, we tested the ability of IP to modify oxidative stress induced by extremely high intraabdominal pressures.

METHODS

Twenty-five female pigs were studied and divided in three groups: a control group, a pneumoperitoneum group (with pressure of 30 mmHg), and an ischemic preconditioning group (initially subjected to preconditioning with pressure of 25 mmHg for 15 min and desufflation for 15 min and then to pneumoperitoneum as in pneumoperitoneum group). Blood samples were obtained at identical time intervals in the three groups. Total oxidative capacity, total antioxidative capacity and total nitric oxide (NO), nitrite and nitrate concentrations were measured and compared between groups.

RESULTS

IP increased total antioxidative capacity (p = .045) and protective mediators like nitrite (p = .022). It was also associated with a trend toward lower levels of total oxidative capacity at the end of the abdominal desufflation period but statistical significance was not met.

CONCLUSIONS

IP attenuated oxidative stress induced by IAH, mainly by increasing antioxidative capacity and the levels of protective mediators. The fact that IP was effective, even when used at extremely high levels of intraabdominal pressure, reinforces the interest on this method but further studies are needed to clarify its mechanism of action and potential clinical applications.

Pharmacological modulation of oxidative stress response in minimally invasive surgery: systematic review

This systematic review aims to synthesize the data on the effectiveness of pharmacological modulation of stress response in minimally invasive surgery. Eligible trials were clinical trials randomized or not or experimental trials that investigated the effect of pharmacological agents on modulation of surgical stress response to minimally invasive surgery. No clinical trials were identified. Eight experimental trials met the inclusion criteria and were obtained in full text. Experimental models were rats or rabbits subjected to pneumoperitoneum, or pneumoretroperitoneum, not to a whole operation. Pharmacological modulation of surgical stress response was attempted with erythromycin, melatonin, mesna, verapamil, pentoxifylline, N-acetylcysteine, and zinc. All the pharmacological agents, except pentoxifylline, seemed to reduce oxidative stress markers. However, only mesna pretreatment prevented oxidative stress, because oxidative stress markers remained in the sham levels. Contrasting data were obtained for pentoxyphilline. In conclusion, available data suggest that pharmacological modulation of surgical stress response to minimally invasive surgery might be feasible.

Laparoscopic preconditioning protects against oxidative injury in cerulein-induced pancreatitis rats (an experimental study)

BACKGROUND

Laparoscopic cholecystectomy, particularly in the same hospital stay, has been widely recommended to treat gallstone-pancreatitis over the last decade. Although pancreatitis produces severe oxidative injury, laparoscopy exerts an additional effect over that is produced by pancreatitis. The preconditioning phenomenon previously reported as protective in open surgery is a beneficial maneuver also in laparoscopic surgery. So in the present study we have tried to find out the effect of laparoscopic preconditioning over the pancreatitis in cerulein-induced pancreatitis rats.

METHODS

Acute pancreatitis was induced in 24 rats weighing between 280 and 350 g by three subcutaneous injection of 80 μg/kg of body weight cerulein. A 1-cm midline laparotomy was performed for all rats, and then they were randomly assigned to one of the following three groups (n=8 for each): Group I (control), Group II (laparoscopy), and Group III (laparoscopic preconditioning [L-Pre]). After that, a catheter was placed into the peritoneum for the creation of the pneumoperitoneum (Pp) in all the animals except the control group. The rats of Groups II and III were subjected to 60 minutes of Pp with 15 mm Hg intraabdominal pressure followed by 30 minutes of deflation. The L-Pre procedure was applied to Group III immediately before the laparoscopic procedure. Blood samples were taken for biochemical assays. Pancreas tissue samples were taken for light microscope analysis.

RESULTS

The light microscopy of the pancreas tissues revealed that cerulein injection caused edema and sparse inflammatory cell infiltration mimicking the edematous pancreatitis. However, the application of laparoscopy over the pancreatitis produced significant inflammatory cell infiltration, acinus vacuolization, and necrosis (in one case) in addition to edema. But, the laparoscopic preconditioning maneuver applied before the laparoscopy significantly decreased in particular acinary vacuolization and cell infiltration. Therefore the total sum of the histopathological score of the L-Pre group was significantly less than that of the laparoscopy group. The biochemical analysis of the groups revealed that laparoscopy caused significant elevation of malondialdehyde levels and decrease of reduced glutathione values. However, the addition of preceding preconditioning produced significant amelioration of these parameters.

CONCLUSION

Laparoscopic preconditioning may be a useful method to decrease the oxidative injury in cases undergoing cholecystectomy for biliary pancreatitis. But, it should be emphasized that this was a restricted experimental study, and further clinical studies are needed to adopt these results into clinical settings.

Systematic review of oxidative stress associated with pneumoperitoneum

Background

There have been several reports of ischaemic complications after routine laparoscopy. The aim of this review was to investigate the relationship between this oxidative stress and pneumoperitoneum.

Methods

Medline, Medline in-process, The Cochrane Library, PubMed and EMBASE were searched for papers on oxidative stress and pneumoperitoneum, from 1947 to March 2008 with no language restriction or restriction on trial design. Papers that did not investigate pneumoperitoneum as a causative factor, or did not report outcome measures related to oxidative stress, were excluded.

Results

A total of 73 relevant papers were identified: 36 animal studies, 21 human clinical trials, nine case reports, five review articles and two comments. Pneumoperitoneum causes a reduction in splanchnic blood flow, resulting in biochemical evidence of oxidative stress in a pressure- and time-dependent manner. There is evidence that the use of carbon dioxide for insufflation is contributory. Several measures proposed to minimize the oxidative stress have shown promise in animal studies, but few have been evaluated in the clinical setting.

Conclusion

There is an increasing body of evidence, mainly from animal studies, that pneumoperitoneum decreases splanchnic perfusion with resulting oxidative stress. It is now appropriate to investigate the clinical significance of pneumoperitoneum-associated oxidative stress.

Up regulation of IL-6 by ischemic preconditioning in normal and fatty rat livers: Association with reduction of oxidative stress

We analyzed the role of IL-6 in the protection that ischemic preconditioning (IP) exerts against hepatic ischemia reperfusion-mediated (I/R) oxidative damage, particularly in fatty livers. IP-related IL-6 up-regulation during reperfusion in steatotic and non-steatotic livers was correlated with reduced indices of liver damage, as also demonstrated by pharmacological modulation of IL-6. IP activated NF-kB and HSF during ischemia (Isc), whereas AP-1 activity was unaffected. IP blunted the activation of STAT3 and stress-responsive genes, such as NF-kB, AP-1 and heme oxygenase (HO-1) during reperfusion. The role of reduced oxidative stress in hepatoprotection of fatty livers was further demonstrated by the fact that: (i) IP prevented the decrease of glutathione levels and the increase of lipid peroxidation; (ii) the anti-oxidant GSH-ester prevented lipid peroxidation and necrosis. In conclusion, IP modulates the activity of transcription factors and triggers IL-6 production; this may prevent hepatic I/R damage in a oxidative stress-dependent way, particularly in fatty livers.

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

BACKGROUND

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.

METHODS

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).

RESULTS

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).

CONCLUSION

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.

The comparative effects of pneumoperitoneum on apoptosis and p53 expression in gastrointestinal organs

BACKGROUND

Laparoscopic surgical techniques have been increasingly preferred to classic laparotomy by surgeons since 1987. The pneumoperitoneum is often used to facilitate the intra-abdominal field, but it carries the risk of its ischemic potential and has differences [l2]of metabolic, inflammatory, and infectious consequences, depending on the pressure set and kind of gas used. However, the mechanisms related with the cell injury observed after laparoscopy are still unknown. The aim of this study was to evaluate the effects of different pressures of CO(2) on apoptosis and p53 expression in small and large intestines and the stomach.

MATERIALS AND METHODS

In total, 30 Sprague-Dawley male rats were used in the study. CO(2) is insufflated into the intra-abdominal cavity through a angiocatheter cannule by an insufflator set at two different pressures of 10 and 20 mm Hg during 60 minutes. In the control group, the cannule was inserted into the intra-abdominal cavity without any other surgical procedure and no gas was insufflated. After 60 minutes, the rats were sacrificed and a laparotomy was performed. The small and large intestines and stomach were excised. The samples were histologically processed and an immunohistochemical analysis was performed.

RESULTS

The results of the study revealed that the number of apoptotic cells in intra-abdominal organs we studied increased in proportion to the CO(2) pressure level. However, the p53 expression was detected only in the stomach.

CONCLUSIONS

Our study showed that the number of apoptotic cells rises in parallel to the increase in intra-abdominal pressure following the CO(2) pneumoperitoneum in rat large and small intestine and stomach. Although the apoptosis was activated by the p53 pathway in the stomach, it was not so in the large and small intestine.

Preconditioning-like amelioration of erythropoietin against laparoscopy-induced oxidative injury

BACKGROUND

Laparoscopic surgery has gained wide acceptance for almost every kind of surgical procedure, although it has produced significant oxidative injury to intraabdominal organs depending on the pressure level and the kind of the gas used. The literature describes several preventive measures for decreasing the postlaparoscopic oxidative injury such as low intraabdominal pressure, gasless laparoscopy, and laparoscopic preconditioning. Erythropoietin was shown previously to decrease ischemia-reperfusion injury to the liver. The current study evaluated the effect of erythropoietin against laparoscopy-induced oxidative injury, as compared with laparoscopic preconditioning.

METHODS

For this study, 64 male Spraque-Dawley rats were randomly assigned to one of the following groups. The control group was subjected to a sham operation. The laparoscopy group was subjected to 60 min of pneumoperitoneum. The laparoscopic preconditioning plus laparoscopy group was subjected to 5 min of insufflation and 5 min of desufflation followed by 60 min of pneumoperitoneum. The erythropoietin plus laparoscopy group was subjected to a subcutaneous injection of erythropoietin as a single 1,000-U/kg dose followed by 60 min of pneumoperitoneum. After 45 min of desufflation subsequent to cessation of pneumoperitoneum, blood, liver, and kidney samples were obtained from half of the rats. The other half of the rats were observed for a reperfusion period of 24 h. Tissue and blood samples also were obtained after this period.

RESULTS

Laparoscopy produced significant oxidative injury, as compared with the sham treatment. Laparoscopic preconditioning produced significant amelioration of the ischemic injury. Although erythropoietin administration during the prelaparoscopic period decreased the pneumoperitoneum-induced oxidative injury, the beneficial effect of laparoscopic preconditioning was more pronounced.

CONCLUSION

Laparoscopic preconditioning is more effective than the preischemic administration of erythropoietin in reducing laparoscopy-induced oxidative injury.