Can preconditioning reduce laparoscopy-induced tissue injury?

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.

Reappraisal of ischemia-reperfusion injury in a short duration laparoscopic surgery, a pilot study

Background

Serum biochemical changes during laparoscopic surgery and positive pressure pneumoperitoneum (PP) may reflect mild oxidative stress due to the ischemia-reperfusion (I/R) mechanism. However, there is still a controversy regarding the exact mechanism of PP in creating oxidative stress and whether the induction of PP causes I/R effects at all. To elucidate this debated issue, we studied, for the first time, the changes of I/R parameters in the serum, in a pilot study, during laparoscopic cholecystectomy using a reliable, independent exogenous oxidative biomarker, together with common intrinsic biomarkers of oxidative stress.

Patients and methods

Our study included 20 patients scheduled for elective laparoscopic cholecystectomy. We evaluated the levels of the extrinsic and endogenous markers for oxidative stress during awareness, under anesthesia, the end of surgery (abdominal CO2 evacuation), and 2 h afterward.

Results

After an initial increase in oxidative stress following anesthesia, we did not notice any further significant rise in the levels of the synthetic exogenous and the endogenous biomarkers at the end of the surgery and 2 h later on. However, a positive correlation was noted between the levels of both the intrinsic and extrinsic markers.

Conclusions

In our study, the capability of the extrinsic biomarker to detect mild oxidative stress was not validated. Our study stresses the heterogeneous nature of the oxidative reactions and the diversity of the endogenous and exogenous biomarkers while detecting various biochemical patterns under mild oxidative stress, during the short period of laparoscopic surgery.

Hydromorphone Protects against CO2 Pneumoperitoneum-Induced Lung Injury via Heme Oxygenase-1-Regulated Mitochondrial Dynamics

Various pharmacological agents and protective methods have been shown to reverse pneumoperitoneum-related lung injury, but identifying the best strategy is challenging. Herein, we employed lung tissues and blood samples from C57BL/6 mice with pneumoperitoneum-induced lung injury and blood samples from patients who received laparoscopic gynecological surgery to investigate the therapeutic role of hydromorphone in pneumoperitoneum-induced lung injury along with the underlying mechanism. We found that pretreatment with hydromorphone alleviated lung injury in mice that underwent CO₂ insufflation, decreased the levels of myeloperoxidase (MPO), total oxidant status (TOS), and oxidative stress index (OSI), and increased total antioxidant status (TAS). In addition, after pretreatment with hydromorphone, upregulated HO-1 protein expression, reduced mitochondrial DNA content, and improved mitochondrial morphology and dynamics were observed in mice subjected to pneumoperitoneum. Immunohistochemical staining also verified that hydromorphone could increase the expression of HO-1 in lung tissues in mice subjected to CO₂ pneumoperitoneum. Notably, in mice treated with HO-1-siRNA, the protective effects of hydromorphone against pneumoperitoneum-induced lung injury were abolished, and hydromorphone did not have additional protective effects on mitochondria. Additionally, in clinical patients who received laparoscopic gynecological surgery, pretreatment with hydromorphone resulted in lower serum levels of club cell secretory protein-16 (CC-16) and intercellular adhesion molecule-1 (ICAM-1), a lower prooxidant-antioxidant balance (PAB), and higher heme oxygenase-1 (HO-1) activity than morphine pretreatment. Collectively, our results suggest that hydromorphone protects against CO₂ pneumoperitoneum-induced lung injury via HO-1-regulated mitochondrial dynamics and may be a promising strategy to treat CO₂ pneumoperitoneum-induced lung injury.

Pneumoperitoneum preconditioning for the prevention of renal function after laparoscopic partial nephrectomy: protocol for a double-blind randomised controlled trial

INTRODUCTION

Renal ischaemia reperfusion injury is an inevitable pathophysiology in different clinical situations including laparoscopic partial nephrectomy (LPN), which can obviously decrease the renal function after surgery. Pneumoperitoneum preconditioning (PP) is a promising approach that can yield a protective effect on kidney, which has already been demonstrated in some animal models. The present study is designed to assess whether the PP can yield a clinical renoprotective role after LPN.

METHODS AND ANALYSIS

This study is a randomised, prospective, double-blind and parallel controlled clinical trial. Eligible participants will be patients with renal tumours and willing to choose elective LPN. Patients randomised to the treatment arm will receive PP consisted of three cycles of 5 min insufflation and 5 min desufflation before LPN, while the control arm will receive a sham operation. The primary endpoints are glomerular filtration rate and the level of serum cystatin C within 6 months after desufflation. The secondary endpoints are serum creatinine, estimated glomerular filtration rate, alanine transaminase, serum amylase, intestinal fatty acid binding protein, postoperative hospital stay, the incidence of adverse events and mortality in postoperative 6 months.

ETHICS AND DISSEMINATION

This study has been approved by the institutional ethics committee of Nanjing First Hospital. The results of this study will be reported faithfully through scientific conferences or published articles.

TRIAL REGISTRATION NUMBER

NCT03822338.

Protective effects of postconditioning in transvaginally created pneumoperitoneum

There are reports of ischemic complications in clinical practice after laparoscopy using pneumoperitoneum. Conditioning has a beneficial effect for various ischemic diseases. This experimental study was designed to evaluate the effects of postconditioning in transvaginally created pneumoperitoneum. Sixty adult female rats, weighing 300±50 g were divided into four equal groups. Pneumoperitoneum was created by CO₂ insufflation under a pressure of 10 mmHg. Rats in the first group (sham) were subjected to only sham-operation or gas insufflation. The second group (TV/PP) was subjected to pneumoperitoneum for 60 min followed by 30 min of desufflation. The third group (post-5) was subjected to pneumoperitoneum for 60 min followed by 5 min of desufflation, 5 min of insufflation and again followed by 30 min of desufflation. The fourth group (post-2.5) was subjected to pneumoperitoneum for 60 min followed by 2.5 min of desufflation and 2.5 min of insufflation-repeated in two cycles- and then followed by 30 min of desufflation. The rats were sacrificed, and blood was collected after 30 min, 2 and 6 h from the last desufflation. Levels of oxidative stress markers, malondialdehyde (MDA), superoxide dismutase (SOD), reduced glutathione (GSH), sulfhydryl groups (SH) and inflammatory cytokine TNF-α, were analyzed. Levels of MDA in the post-5 group were significantly reduced compared to the TV/PP and post-2.5 groups. The level of GSH in TV/PP animals was markedly reduced compared to the Sham, Post-5 and Post-2.5 groups. In addition, levels of SH were increased in the Post-5 group in comparison to the Sham, TV/PP and Post-2.5 groups. No difference in the activity of SOD between the groups was found, and the concentration of TNF-α in TV/PP animals was significantly higher than that in the Sham and postconditioning groups. Overall, the results of the present study indicate that postconditioning can reduce pneumoperitoneum-induced oxidative injury.

Outcome of kidney function after ischaemic and zero-ischaemic laparoscopic and open nephron-sparing surgery for renal cell cancer

Background

Nephron-sparing surgery (NSS) remains gold standard for the treatment of localised renal cell cancer (RCC), even in case of a normal contralateral kidney. Compared to radical nephrectomy, kidney failure and cardiovascular events are less frequent with NSS. However, the effects of different surgical approaches and of zero ischaemia on the postoperative reduction in renal function remain controversial.

We aimed to investigate the relative short- and long-term changes in estimated glomerular filtration rate (eGFR) after ischaemic or zero-ischaemic open (ONSS) and laparoscopic NSS (LNSS) for RCC, and to analyse prognostic factors for postoperative acute kidney injury (AKI) and chronic kidney disease (CKD) stage ≥3.

Methods

Data of 444 patients (211 LNSS, 233 ONSS), including 57 zero-ischaemic cases, were retrospectively analysed. Multiple regression models were used to predict relative changes in renal function. Natural cubic splines were used to demonstrate the association between ischaemia time (IT) and relative changes in renal function.

Results

IT was identified as significant risk factor for short-term relative changes in eGFR (ß = − 0.27) and development of AKI (OR, 1.02), but no effect was found on long-term relative changes in eGFR. Natural cubic splines revealed that IT had a greater effect on patients with baseline eGFR categories ≥G3 concerning short-term decrease in renal function and development of AKI. Unlike LNSS, ONSS was significantly associated with short-term decrease in renal function (ß = − 13.48) and development of AKI (OR, 3.87). Tumour diameter was associated with long-term decrease in renal function (ß = − 1.76), whereas baseline eGFR was a prognostic factor for both short- (ß = − 0.20) and long-term (ß = − 0.29) relative changes in eGFR and the development of CKD stage ≥3 (OR, 0.89).

Conclusions

IT is a significant risk factor for AKI. The short-term effect of IT is not always linear, and the impact also depends on baseline eGFR. Unlike LNSS, ONSS is associated with the development of AKI. Our findings are helpful for surgical planning, and suggest either the application of a clampless NSS technique or at least the shortest possible IT to reduce the risk of short-time impairment of the renal function, which might prevent AKI, particularly regarding patients with baseline eGFR category ≥G3.

Pneumoperitoneum induced ischemia-reperfusion injury of the peritoneum - Preconditioning may reduce the negative side-effects caused by carbon-dioxide pneumoperitoneum - Pilot study

INTRODUCTION

Laparoscopy is more beneficial than the conventional open technique, however the pneumoperitoneum created may have an ischemic side effect.

OBJECTIVE

Our aim was to evaluate the protective effects of preconditioning during laparoscopic cholecystectomies (LC).

METHODS

30 patients were randomized into 2 groups: I. PreC (preconditioning: 5 min. inflation, 5 min. deflation, followed by conventional LC), II: LC (conventional LC). Blood samples were taken before hospitalization (C = control), before surgery, after anaesthesia (B.S.), after surgery (A.S.) and 24 hours after the procedure (24 h). Measured parameters were: malondialdehyde (MDA), reduced glutathione (GSH), sulfhydril groups (-SH), superoxide-dismutase (SOD), catalase (CAT), myeloperoxidase (MPO), length of hospitalization and pain (VAS = visual analogue scale).

RESULTS

Compared to the BS levels, no significant changes were detected in SOD's activity and MDA levels. GSH concentrations were significantly increased in the PreC group after operation. SH-, MPO, CAT and liver function enzymes were not significantly different. Hospitalization was shorter in the PreC group. Based on the VAS score patients had less pain in the PreC group.

CONCLUSION

Significant differences concerning PreC group were found in GSH values. In the PreC group pain decreased by 2-2.5 units following the procedure, 24 h after surgery, and hospitalisation was also significantly shorter. In our pilot study the potential protective effect of preconditioning could be defined.

Partial renal resection by LaparoNewPro: in vivo open and laparoscopic study in an animal model

INTRODUCTION

The aim of this research project was to test an incremental bipolar radiofrequency generator with open and laparoscopic inline electrode probe for partial renal resection without vascular clamping.

MATERIAL AND METHODS

Sixteen polar resections with clamping and six without were performed in four pigs in the acute phase. Three pigs underwent laparoscopic polar resection and were live housed for ten days and reoperated to verify the presence of hematic and urinary collection and the condition of the renal edge. Five pigs underwent laparoscopic polar resection without clamping, and two of these were live housed and reoperated after ten days.

RESULTS

Polar renal resection by our system (LaparoNewPro) turned out to be effective and safe, without cardio-respiratory complications or damage to the remaining parenchyma. Coagulation of the renal parenchyma before resection is effective and safe; at the reoperation, no complications were observed. The laparoscopic version of the probe is ergonomic and safe, with effective coagulation and a small amount of smoke produced. No complications occurred in the housed animals. No damage, local or to residual parenchyma, or thrombosis of the renal vessels were found.

CONCLUSIONS

LaparoNewPro is able to deliver coagulation of the resection line effectively and independently of clamping of the vessels both in the open and laparoscopic approaches. Coagulation times are short, the automatism of the generator is reliable, and the open and laparoscopic probes are ergonomic.

The effects of adding ischemic preconditioning during desflurane inhalation anesthesia or propofol total intravenous anesthesia on pneumoperitoneum-induced oxidative stress

BACKGROUND

The aim of the study was to explore the differences in oxidative stress during anesthesia with desflurane/N₂O or propofol/remifentanil in patients undergoing laparoscopic cholecystectomy and additionally to evaluate the differential effects of desflurane and propofol on ischemic preconditioning (IP).

MATERIALS AND METHODS

One hundred patients were randomly allocated to four groups. For anesthesia maintenance, the inhalation group (Group I) and the inhalation plus IP group (Group IIP) received desflurane at an end-tidal concentration of 4-6 vol% in oxygen/N₂O, and the TIVA group (Group T) and TIVA plus IP group (Group TIP) received infusions of propofol and remifentanil. In Groups IIP and TIP, IP was carried out by 10 min of pneumoperitoneum followed by 10 min of deflation. Preoperative and postoperative plasma total antioxidant status (TAS), total oxidant status (TOS), paraoxonase, stimulated paraoxonase, arylesterase, ceruloplasmin, and myeloperoxidase levels were analyzed; oxidative stress index (OSI) was calculated.

RESULTS

When oxidative stress parameters were compared between groups, myeloperoxidase values in Group I were statistically significantly lower compared to Group TIP (p = .004 with Bonferroni's correction). There were no differences between preoperative and postoperative TAS, paraoxonase, stimulated paraoxonase, arylesterase, or ceruloplasmin levels (p > .05). In intragroup evaluations, postoperative paraoxonase and stimulated paraoxonase levels were found to be lower than preoperative values in Group TIP (p = .021 and .012, respectively).

CONCLUSION

In laparoscopic cholecystectomy lasting less than 60 min, there were no differences in the measured oxidative stress parameters between maintenance of anesthesia by desflurane/N₂O and propofol/remifentanil/N₂O. The addition of 10 min IP administration during both anesthesia techniques did not result in additional changes in the analyzed oxidative stress.

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.

Protective effect of theophylline on renal functions in experimental pneumoperitoneum model

Our objective in this experimental study is to research the effect of the intra-abdominal pressure which rises following pneumoperitoneum and whether Theophylline has a possible protective activity on this situation. In our study, 24 Wistar Albino rats were used. Rats were divided into two groups. The first group was set for only pneumoperitoneum model. The second group was given 15 mg/kg of Theophylline intraperitoneally before setting pneumoperitoneum model. Then urea, creatinine, cystatin-C, tissue and serum total antioxidant capacity, total oxidant capacity and oxidative stress index in two groups were measured and compared with each other. Apoptosis and histopathological conditions in the renal tissues were examined. The differences between the groups were analyzed with the Mann-Whitney U test. Results were considered significant at p < 0.05. No statistically significant difference was determined between tissue and serum averages in two groups in terms of TAS, TOS and OSI values (p > 0.05). The mean value of urea were similar in pneumoperitoneum and pneumoperitoneum + theophylline groups (p = 0.12). The mean cystatin-C value was 2.2 ± 0.3 µg/mL in pneumoperitoneum, 1.74 ± 0.33 µg/mL in pneumoperitoneum + theophylline (p = 0.002). According to our study, lower cystatin-C levels in the group, where Theophylline was given, are suggestive of lower renal injury in this group. However, this opinion is interrogated as there is no difference in terms of tissue and serum TAS, TOS, OSI and urea values between the groups.

Selected oxidative stress markers in gynecological laparoscopy

INTRODUCTION

The surgical stress response after laparoscopy is smaller when compared with open surgery, and it is expected that after minimally invasive surgery the possible development of oxidative stress will be less severe.

AIM

To evaluate markers of pro-oxidant activity - levels of lipid peroxides and malondialdehyde - and activity of the antioxidant enzymes superoxide dismutase and glutathione peroxidase in the perioperative period in patients undergoing gynecological laparoscopy and to determine whether the duration of laparoscopy can affect these changes.

MATERIAL AND METHODS

The study included 64 patients, divided into two groups: group 1 with duration of laparoscopy up to 20 min, and group 2 with duration of the operation over 40 min. Blood samples were collected before anesthesia, 5 min after release of pneumoperitoneum, and 10 h after surgery.

RESULTS

A statistically significant increase in the levels of lipid peroxides and malondialdehyde in samples collected after surgery was found in comparison with values obtained before surgery. Also statistically significant differences existed between groups of patients with different duration of surgery. Superoxide dismutase and glutathione peroxidase activity values were significantly decreased. They were also significantly different between the two groups with different duration of surgery.

CONCLUSIONS

In our study, levels of the markers of pro-oxidant activity increased and levels of the markers of antioxidant enzymes decreased, suggesting development of oxidative stress. The duration of laparoscopic procedures affects the severity of the presented changes.

Deleterious Effects of Increased Intra-Abdominal Pressure on Kidney Function

Elevated intra-abdominal pressure (IAP) occurs in many clinical settings, including sepsis, severe acute pancreatitis, acute decompensated heart failure, hepatorenal syndrome, resuscitation with large volume, mechanical ventilation with high intrathoracic pressure, major burns, and acidosis. Although increased IAP affects several vital organs, the kidney is very susceptible to the adverse effects of elevated IAP. Kidney dysfunction is among the earliest physiological consequences of increased IAP. In the last two decades, laparoscopic surgery is rapidly replacing the open approach in many areas of surgery. Although it is superior at many aspects, laparoscopic surgery involves elevation of IAP, due to abdominal insufflation with carbonic dioxide (pneumoperitoneum). The latter has been shown to cause several deleterious effects where the most recognized one is impairment of kidney function as expressed by oliguria and reduced glomerular filtration rate (GFR) and renal blood flow (RBF). Despite much research in this field, the systemic physiologic consequences of elevated IAP of various etiologies and the mechanisms underlying its adverse effects on kidney excretory function and renal hemodynamics are not fully understood. The current review summarizes the reported adverse renal effects of increased IAP in edematous clinical settings and during laparoscopic surgery. In addition, it provides new insights into potential mechanisms underlying this phenomenon and therapeutic approaches to encounter renal complications of elevated IAP.

Does prolonged pneumoperitoneum affect the kidney? Oxidative stress, stereological and electron microscopy study in a rat model

PURPOSE

Pneumoperitoneum (Pp) at 12 to 15 mmHg in rats is associated with kidney damage. However, Pp at 8 mmHg is now known to best correlate to working pressures used in humans. Thus the aim of this work was to study the kidney of rats submitted to prolonged Pp at 8 mmHg.

MATERIALS AND METHODS

Rats were divided into a Sham group (n = 14), submitted to anesthesia, and a Pp group (n = 14), submitted to Pp at 8 mmHg, followed by deflation. In both groups, 7 animals were immediately killed and their kidneys were used for oxidative stress analyses. The remaining 7 rats in each group were evaluated after 6 weeks for the number of glomeruli and podocyte morphology.

RESULTS

For all analyzed parameters Sham and Pp groups presented no statistical difference.

CONCLUSION

When submitted to adequate Pp pressures (8 mmHg), no kidney damage occurs in rats.

Comparison between laparoscopic and open partial nephrectomy: surgical, oncologic, and functional outcomes

The surgical, oncologic, and functional outcomes were retrospectively compared of laparoscopic partial nephrectomy (LPN) and open partial nephrectomy (OPN) for the treatment of renal masses. Between January 2006 and November 2011, 115 LPNs and 97 OPNs were performed. The patients' demographics were matched. Their intraoperative and postoperative data, oncologic and renal function outcomes were compared. Surgical time, renal arterial occlusion time, estimated blood loss, and postoperative hospitalization days were shorter in the LPN group (p < 0.01). The total complications were comparable; however, LPN had a higher intraoperative complication due to 12 subcutaneous emphysemas. The LPN group was followed up with a mean time of 29.3 ± 14.4 months and the OPN group with a mean time of 31.2 ± 12.6 months. All patients survived and no distant relapse or metastasis were observed. Kaplan-Meier estimates of 60-month local recurrence-free survival were comparable with 92.4% after LPN and 93.8% after OPN, respectively (p = 0.57). The reduction of glomerular filtration rate was more obvious after LPN at the 3-month follow-up (p < 0.01), but similar between the two groups at the 30.2-month follow-up. LPN provides similar results in oncologic and functional outcomes when compared to OPN. Long-term observations are still required to the oncologic and function outcomes.

Caffeic acid phenethyl ester (CAPE) protects against acute urogenital injury following pneumoperitoneum in the rat

PURPOSE

Our aim is to determine the biochemical and histologic changes induced in the kidneys, testis and prostate on possible ischemia and reperfusion (I/R) injury caused by pneumoperitoneum (PNP) in a rat model and to evaluate the ability of protective effects of caffeic acid phenethyl ester (CAPE).

METHODS

Twenty-eight adult male Wistar albino rats were randomly divided to one of three treatment groups, with seven animals in each group. Sham, laparoscopy (L), and laparoscopy plus CAPE (L + C) group were subjected to 60 min of PNP with 15 mmHg one hour before the desufflation period. Total oxidant status (TOS) and total antioxidant status (TAS) levels were determined in kidney, testis, and prostate. Kidney and testis tissues were removed to obtain a histologic score. Also, Johnsen scoring system was used for testicular tissue analysis.

RESULTS

L group had significantly higher TOS and lower TAS levels on kidney and testis compared to the other groups. In prostate biochemical analysis, there was not any difference between groups. No difference was found between groups according to kidney and testis tissues' histologic evaluation. In evaluation of Johnsen scoring, L group showed significant lower score compared to the other two groups.

CONCLUSIONS

Increased intraabdominal pressure (IAP) had an oxidative effect on kidney and testis but not on prostate in rats. Moreover, it could affect the testicular Johnsen score. All these adverse effects of IAP on both kidney and testis could be prevented by CAPE administration.

Acute obstructive jaundice and chronic cirrhosis protect against the adverse renal effects of pneumoperitoneum: role of nitric oxide

BACKGROUND

Obstructive jaundice and cirrhosis are associated with impaired renal function. Previously we demonstrated that increased intra-abdominal pressure (IAP, pneumoperitoneum) in normal rats induced renal dysfunction. This study investigated the renal effects of pneumoperitoneum in rats with acute jaundice and cirrhotic rats.

METHODS

Following a baseline period, rats with obstructive jaundice or cirrhosis induced by acute or chronic bile duct ligation (BDL), respectively, and their sham-controls were subjected to consecutive IAPs of 10 and 14 mmHg for 45 min each. Urine flow (V), Na(+) excretion (UNaV), glomerular filtration rate (GFR), renal plasma flow (RPF), and urinary NO metabolites ([Formula: see text]) and cGMP (UcGMP) were determined.

RESULTS

Elevating IAP from 0 to 10 and 14 mmHg in normal rats caused IAP-dependent reductions in V, UNaV, GFR, RPF, [Formula: see text] and UcGMP. Basal renal function and hemodynamics were lower in rats with obstructive jaundice. In contrast to normal rats, application of elevated IAP of 10 and 14 mmHg significantly improved V, UNaV, GFR, RPF, and MAP along with increased [Formula: see text] and preserved UcGMP. Similarly, when identical IAP conditions were applied to cirrhotic rats, no deleterious changes in V, UNaV, GFR or RPF were observed.

CONCLUSIONS

Application of pneumoperitoneum to rats with acute BDL improves kidney function and renal hemodynamics. Likewise, increased IAP does not exert adverse renal effects in cirrhotic rats. These effects are distinct from the deleterious renal consequences of increased IAP in normal rats. Perturbations in the generation of NO/cGMP during IAP in normal rats but not in rats with BDL or cirrhosis may contribute to these differences.

Laparoscopy can aggravate the severity of pancreatitis in an experimental rat model

PURPOSE

Over the past decade, laparoscopic techniques have markedly evolved, and it has been shown that minimally invasive surgery can provide a safe, effective, and less traumatic management of various surgical diseases. Additionally, it is well known that pancreatitis itself also produced severe oxidative tissue injury by increasing levels of reactive oxygen species. This study therefore aimed to investigate the effects of pneumoperitoneum on the severity of pancreatitis in a rat model of acute pancreatitis induced by cerulein.

MATERIALS AND METHODS

Thirty-five Wistar albino rats were divided into five groups with seven rats in each. Experimental pancreatitis was induced using intraperitoneal injection of cerulein. The first group received open laparotomy. Groups 2-5 were treated with 5, 10, 15, and 20 mm Hg, respectively, achieved by applying pressure and waiting for 60 minutes. After this waiting interval, all of the rats were sacrificed; blood samples were taken by intracardiac puncture for biochemical assays, and pancreatic tissue samples were taken for light microscope analysis. Histopathology was scored according to edema, granulation, polymorphonuclear leukocytes, and mononuclear cells in all groups.

RESULTS

Great increases in malondialdehyde and reduced glutathione levels were seen in all of the groups in which pancreatitis was induced. In Group 2-5, more significant increases were detected than in the open laparotomy group (P<.005). In the histopathological examination, Groups 2-5 showed more inflammatory cell infiltration, edema, and granulation tissue than the open laparotomy group (P<.005).

CONCLUSIONS

It is useful to remember the parameters of the medical treatment of pancreatitis. While surgical treatment is being decided, we think that the process of all kinds of surgery, including laparoscopic surgery, can increase the severity of pancreatitis.

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.

Renal histopathology features according to various warm ischemia times in porcine laparoscopic and open surgery model

BACKGROUND

Thirty minutes has been considered as the threshold for tolerable warm ischemic time (WIT). Recent reports demonstrate recovery of renal function after longer WIT. We assessed renal histology according to different WIT in a 2-kidney porcine model.

METHODS

Twelve female pigs were randomized to an open or laparoscopic group. Each pig was further randomized within each group to clamping the left renal artery for 5, 15, 30, 45, 60 or 180 minutes. Preclamping left renal biopsies were performed on each pig. The contralateral kidney in each animal was used as an individual control. On postoperative day 14, all animals underwent bilateral nephrectomies. Preclamping left renal biopsies and all renal specimens were evaluated by a blinded veterinary pathologist.

RESULTS

One pig died in the open group after 180 minutes of clamping. Histopathology did not show any significant changes between the two groups and across clamp times from 5 to 60 minutes. After 180 minutes of laparoscopic clamping, there was evidence of diffuse necrosis.

INTERPRETATION

Sixty minutes of ischemia did not show any permanent renal damage in both groups. Further studies are needed to verify these findings in humans. A prolonged ischemic time without permanent renal damage would be helpful in partial nephrectomy. Warm ischemic time of 180 minutes exceeded the renal ischemic burden based on histological features.

Warming and humidification have no effect on oxidative stress during pneumoperitoneum in rats

Pneumoperitoneum is reported to induce oxidative stress due to the desiccative effect of cold, dry gas insufflation. The aim of this study is to compare the effect of warmed, humidified insufflation to standard gas, by measuring oxidative stress markers in a physiologically relevant animal model. Twenty male Wistar rats (330?650 g) were alternately assigned to the Warm Humidified group (WH, n = 10) and Control group (n = 10). All rats underwent pneumoperitoneum at 5 mmHg and a controlled flow rate for 110 min. The WH group received warmed (37?C) and humidified (98% Relative Humidity (RH)) gas and the control group received standard gas at room temperature (19?C) and 0% RH. At the end of pneumoperitoneum, samples of liver, kidney, pancreas, jejunum, and lung were excised. Levels of plasma and tissue malondialdehyde (MDA) and protein carbonyls (PC) were measured. Organ light microscopy was performed. There were no differences between groups for MDA or PC concentrations in plasma, liver, kidney, jejunum, or lung tissue. There were no differences in histological score between groups. Warming and humidification of pneumoperitoneum insufflation gas have no effect on measures of oxidative stress compared to non-warmed, non-humidified controls.

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.

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

Increased 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.

What should be the ideal time for ischemic preconditioning in a laparoscopic rat model?

BACKGROUND

Pneumoperitoneum (Pp) induces an ischemia and reperfusion (I/R) injury as a result of released oxidative stress markers. Ischemic preconditioning (IP) is one of the used methods to reduce the harmful effects of Pp, which is a mechanism for reducing organ I/R injury by a brief period of organ ischemia. The aim of this study was to investigate the ideal time for IP in the laparoscopic model.

METHODS

Thirty-two rats were assigned into four groups: group 1 (control, n = 8) was subjected to a sham operation. Group 2 (5-minutes IP, n = 8) was subjected to 5 minutes of Pp with 15 mm Hg of pressure followed immediately by 5 minutes of deflation, and after that, 60 minutes of Pp with 15 mm Hg, followed by 60 minutes of deflation. Group 3 (10-minutes IP, n = 8) was subjected to 10 minutes of Pp and 10 minutes of deflation. Group 4 (Pp only, n = 8) was subjected to 60 minutes of Pp with 15 mm Hg of pressure, followed by 60 minutes of deflation. At the end of the experiment, plasma malondialdehyde (MDA) values, the oxidative stress marker, and plasma-reduced glutathione (GSH) levels, the marker showing antioxidant activity, were determined.

RESULTS

Highest plasma MDA values were in group 4 (Pp only), followed by groups 2 and 3 and group 1 (P = 0.181). In addition, IP groups had almost the same values for MDA. Plasma GSH levels in the control group were significantly higher than those in the IP groups and the Pp-only group (P < 0.001). Similarly, as in MDA levels, no difference was found between plasma GSH levels of the IP 5-minutes and IP 10-minutes groups.

CONCLUSIONS

Five minutes of the IP model may be as reliable as 10 minutes of the IP model. In that case, 5 minutes of IP can be more suitable in reducing I/R injury in laparoscopy.

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.

Importance and limits of ischemia in renal partial surgery: experimental and clinical research

Introduction. The objective is to determine the clinical and experimental evidences of the renal responses to warm and cold ischemia, kidney tolerability, and available practical techniques of protecting the kidney during nephron-sparing surgery. Materials and methods. Review of the English and non-English literature using MEDLINE, MD Consult, and urology textbooks. Results and discussion. There are three main mechanisms of ischemic renal injury, including persistent vasoconstriction with an abnormal endothelial cell compensatory response, tubular obstruction with backflow of urine, and reperfusion injury. Controversy persists on the maximal kidney tolerability to warm ischemia (WI), which can be influenced by surgical technique, patient age, presence of collateral vascularization, indemnity of the arterial bed, and so forth. Conclusions. When WI time is expected to exceed from 20 to 30 minutes, especially in patients whose baseline medical characteristics put them at potentially higher, though unproven, risks of ischemic damage, local renal hypothermia should be used.

Evaluation of liver enzymes following elective laparoscopic cholecystectomy: are they really elevated?

BACKGROUND

Studies made on a small number of patients have demonstrated significant modifications in liver function tests (LFT) following laparoscopic cholecystectomy.

AIM

To assess retrospectively, post-operative LFT in a large group of patients undergoing elective uneventful laparoscopic cholecystectomy.

METHODS

Between 1999 and 2007, 1,997 patients were scheduled for laparoscopic cholecystectomy. In 1,034 patients (the study group), the surgery was elective and normal LFT were measured a day prior to surgery. Exclusion criteria included acute cholecystitis, acute pancreatitis, pre-operative endoscopic retrograde cholangio-pancreatography, medication that may affect liver metabolism, and intra-operative complications. Liver function tests were evaluated pre-operatively and 20-24 h post-operatively.

RESULTS

The mean post-operative value of liver function tests and amylase were well within normal limits, although mild increase was inspected in part of it. We observed post-operative mild hepatic enzyme increase only in 41 patients (3.9%), in nine of these, choledocholithiasis was found.

CONCLUSIONS

In contrary to previously published data, we have validated, in light of our broad sampling, that the induction of CO(2) pneumoperitoneum does not cause deranged liver function tests.

The potential role for xanthine oxidase inhibition in major intra-abdominal surgery

BACKGROUND

Xanthine oxidase (XO) is a cytosolic metalloflavoprotein that has been implicated in the pathogenesis of a wide spectrum of diseases, and is thought to be the most important source of oxygen-free radicals and cell damage during re-oxygenation of hypoxic tissues. Clinical studies have already shown that XO inhibition is safe and effective for the treatment of gout, tumour-lysis syndrome, and to reduce complications such as post-operative arrhythmias, myocardial infarction and mortality in cardiovascular surgery. Here, we review the evidence from two decades of animal studies that have investigated the effects of XO inhibition during intra-abdominal surgery.

MATERIALS AND METHODS

A search of the Ovid MEDLINE database from 1950 through January 2007 was carried out using the following search terms: xanthine oxidase, allopurinol, ischemia, reperfusion, intestine, bowel, and general surgery.

RESULTS

The inhibition of XO has been shown to reduce oxidative stress, neutrophil priming, damage to intestinal mucosa due to ischemia reperfusion injuries, intestinal anastomotic dehiscence, bacterial translocation, adhesion formation, distant organ injury and mortality.

CONCLUSIONS

Despite this evidence which very strongly suggests a likely clinically beneficial role for XO inhibition in the elective and acute operative setting, it is surprising that such an approach has not been investigated in general surgery. There is now sufficient evidence to justify dedicated studies to determine the clinical benefits, dosing and duration of XO inhibition before and after gastrointestinal surgery.

Mesna protects splanchnic organs from oxidative stress induced by pneumoperitoneum

BACKGROUND

We investigated the potential beneficial effect of the antioxidant 2-mercaptoethane-sulfonate (mesna) against oxidative stress induced by pneumoperitoneum in splanchnic organs.

METHODS

Wistar rats were subjected to either (a) CO(2) pneumoperitoneum (15 mmHg for 60 min) (group P), (b) pretreatment with mesna (400 mg/kg, p.o.) followed by pneumoperitoneum with a 180 min interval (group MP), (c) sham operation (group S), or (d) administration of mesna only (group M). Forty-five minutes after desufflation (groups P and MP), 60 + 45 min after the induction of anesthesia (group S), or 180 min after mesna administration (group M), tissue specimens were excised from liver, kidneys, jejunum and stomach. Tissue oxidative state was assessed on the basis of glutathione-to-glutathione disulfide ratio, malondialdehyde concentration , and superoxide dismutase activity.

RESULTS

Pneumoperitoneum deteriorated all the oxidative stress markers in the organs studied. Mesna prevented the occurrence of oxidative stress following pneumoperitoneum in all the organs studied. In the absence of pneumoperitoneum, the administration of mesna caused mild enhancement of the oxidative state of liver, stomach, and kidneys compared to sham controls.

CONCLUSIONS

Prophylaxis with mesna prevents oxidative stress induced by pneumoperitoneum in splanchnic organs.

The effect of pentoxifylline on oxidative stress in CO2 pneumoperitoneum

BACKGROUND

Carbon dioxide (CO(2)) pneumoperitoneum induces peritoneal oxidative stress. This experimental, randomized, controlled study was designed to investigate the effect of pentoxifylline on oxidative stress induced by CO(2 )pneumoperitoneum.

METHODS

For this study, 36 Swiss albino rats were randomized into three groups. Arteria, vena femoralis, and peritoneal cavity were cannulated after anesthesia. The arterial pH, partial arterial oxygen pressure (PaO(2)), venous PO(2), arterial and venous PO(2) difference (P((a-v))O(2)), serum aspartate aminotransferase (AST), serum alanine aminotransferase (ALT), and thiobarbituric acid-reactive substances (TBARS) were studied at the end of the first and second hours in group 1 (control). In group 2, 1 cc isotonic NaCl was injected into peritoneal cavity and then CO(2) pneumoperitoneum was established. At the end of the first hour of insufflation and one hour after desufflation, the same parameters as in group 1 were studied. In group 3, the CO(2) pneumoperitoneum plus pentoxifylline group, all procedures as in group 2 were repeated, with the exception of pentoxifylline (50 mg/kg) injected in place of saline.

RESULTS

At the end of the first hour, P((a-v))O(2 )value in group 2 was significantly less than in the control group (group 1) and group 3 (p \ 0.05). There were no significant differences in PaO(2, )pH, AST, and ALT values between groups (p [ 0.05). TBARS level in group 1 was significantly lower than in the other groups, but there was no significant difference in TBARS level between groups 2 and 3. At the end of the second hour, TBARS level in group 3 was significantly lower than in group 2 (p \ 0.05).

CONCLUSIONS

Pentoxifylline may reduce the oxidative injury following laparoscopic procedures.

Physiological responses to endoscopic surgery in children

The knowledge on the physiological impact of endoscopic surgery in infants and children is limited. Cardiovascular effects of pneumoperitoneum are mainly the result of an increase in intraabdominal pressure, absorption of carbon dioxide, and a stimulation of the neurohumoral vasoactive system. In infants, pneumoperitoneum alters the heart rate, mean arterial pressure, left ventricular endsystolic and end-diastolic volume, and meridional wall stress. Urine production is significantly reduced, and cerebral oxygenation and blood flow are altered. However, postoperative immune function is preserved or restored faster, and specific physiological responses to endoscopic surgery are well tolerated by otherwise healthy infants and children. The effects in children with specific conditions, such as sepsis, cancer, or organ dysfunction, remain to be investigated.

Validation and reduction of the oxidative stress following laparoscopic operations: a prospective randomized controlled study

OBJECTIVE

To validate ischemia-reperfusion mechanism during laparoscopic cholecystectomy, and to assess the reduction of oxidative stress by an intermittent sequential pneumatic compression (ISPC) device.

SUMMARY BACKGROUND

Increased intraperitoneal pressure during laparoscopic operations may lead to decreased cardiac output and visceral perfusion, and possible ischemia-reperfusion effects. Using the ISPC device was shown to improve cardiac output and visceral perfusion during pneumoperitoneum (PP).

METHODS

Twenty patients undergoing elective laparoscopic cholecystectomy were enrolled in a randomized prospective controlled study and divided into 2 groups: 1) study group (10 patients), activation of ISPC together with creation of PP; and 2) control group, without ISPC. Lipid peroxidation and glutathione levels (as indicators of oxidative stress) as well as liver and renal function tests, were measured before and at the end of PP, and again at 30 minutes, 4 hours, and 24 hours afterward, together with hemodynamic and respiratory parameters.

RESULTS

There was no significant difference between both groups concerning liver enzymes and bilirubin, nor in hemodynamic parameters. In the control group, increased lipid peroxide levels were noted 4 hours after PP termination, in comparison to pre-PP levels (590.4-649.2 mmol/L, P = 0.002). In the study group (ISPC), such changes were not inspected. Decreased total glutathione levels were noted in the control group, 30 minutes following CO2 evacuation.

CONCLUSIONS

Our study validates the ischemia-reperfusion mechanism following laparoscopic surgery. The use of an ISPC device decreased the oxidative stress (secondary to relative ischemia-reperfusion insult) following PP, probably due to improved cardiac output and visceral perfusion.

Is renal warm ischemia over 30 minutes during laparoscopic partial nephrectomy possible? One-year results of a prospective study

OBJECTIVE

To evaluate renal damage and impairment of renal function 1 yr after laparoscopic partial nephrectomy (LPN) with warm ischemia >30 min.

METHODS

From July 2004 to June 2005, 18 patients underwent LPN with warm ischemia time >30 min. Kidney damage markers (daily proteinuria and tubular enzymes) and renal function (serum creatinine, cystatin C, and creatinine clearances) were assessed on postoperative days 1 and 5 and at 12 mo. Glomerular filtration rate (GFR) was evaluated before surgery and at 3 mo. Renal scintigraphy was performed before the procedure, at 5 d and at 3 and 12 mo postoperatively. Statistical analysis was performed using the Student t test and logistic regression analysis.

RESULTS

In terms of kidney damage and renal function markers, the statistical analysis demonstrated that at 1 yr there was complete return to the normal range and no statistical difference between the values at the various time points. The GFR was not significantly different before and 3 mo after surgery. In terms of scintigraphy of the operated kidney, the values were 48.35+/-3.82% (40-50%) before the procedure, 36.88+/-8.42 (16-50%) on postoperative day 5 (p=0.0001), 40.56+/-8.96 (20-50%) at 3 mo (p=0.003), and 42.8+/-7.2% (20-50%) 1 yr after surgery (p=0.001).

CONCLUSION

Our results demonstrate that kidney damage occurs during LPN when warm ischemia is >30 min. This damage is only partially reversible and efforts should be made to keep warm ischemia within 30 min.

Does Anti-Oxidant Prophylaxis with Melatonin Prevent Adverse Outcomes Related to Increased Oxidative Stress Caused by Laparoscopy in Experimental Rat Model?

BACKGROUND

We hypothesized that prophylaxis with an anti-oxidant should prevent potential adverse outcomes of laparoscopy related to increased oxidative stress in splanchnic organs, including small intestine, liver, and kidneys, and melatonin is the most appropriate agent for this purpose.

METHODS

Twenty-four Sprague-Dawley rats weighing 300 to 350 g were allocated randomly into three groups consisting of eight in each as follows: Group I: gasless (control); group II: 15 mmHg intraabdominal pressure (IAP) with CO2 pneumoperitoneum for 60 min; group III: 15 mmHg IAP with CO2 pneumoperitoneum for 60 min, and melatonin (10 mg/kg) was administered at two occasions, 5 min before insufflation and immediately before the desufflation. In group II and III, rats left resting for 30 min after abdominal deflation, the small intestine (terminal ileum), liver and kidney examples were excised from same locations. The specimens were also obtained using the same time points in group I rats, comprising the control group. The specimens were immediately placed at -80 degrees C for the malondialdehyde (MDA) measurements. In addition, segments of terminal ileum were taken from the similar places in all of the animals for the histological examinations.

RESULTS

Comparisons among the groups revealed that highest mean MDA levels in liver, small intestine and kidney were in the group II, followed by the group III and control group. There was significant difference between mean MDA levels in small intestine, liver and kidney of group II and III (P < 0.0005). However, no significant difference was found between mean MDA levels in small intestine, liver, and kidney of the group III and control group. Mucosa and submucosa were affected significantly in 15 mmHg IAP group (no prophylaxis) when compared with the control and melatonin prophylaxis groups (P = 0.002). However, there was not a significant difference in mean damage score of mucosa, submucosa, and muscular layers in control group when compared to melatonin prophylaxis group.

CONCLUSIONS

This experimental study indicated that melatonin prophylaxis, with anti-oxidant and anti-inflammatory actions, may have an important role in the prevention of potential complications related to oxidative stress injury on splanchnic organs induced by laparoscopy.

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.