Bucillamine improves hepatic microcirculation and reduces hepatocellular injury after liver warm ischaemia-reperfusion injury

BACKGROUND

Liver transplantation and resection surgery involve a period of ischaemia and reperfusion to the liver which initiates an inflammatory cascade resulting in liver and remote organ injury. Bucillamine is a low-molecular-weight thiol antioxidant that is capable of rapidly entering cells.

METHODS

The effect of bucillamine was studied in a rat model of liver ischaemia-reperfusion injury with 45 min of partial (70%) liver ischaemia and at 3 and 24 h of reperfusion. Controls included ischaemia-reperfusion (I/R) only, sham and bucillamine alone (without ischaemia reperfusion). Liver injury was assessed by serum transaminases (AST and ALT). Sinusoidal blood flow and hepatocyte apoptosis were measured using intravital microscopy (IVM).

RESULTS

The hepatocellular injury of I/R produced a markedly elevated serum AST which was reduced with bucillamine (2072.5 +/- 511.79 vs. 932 +/- 200.8, P < 0.05) at 3 h reperfusion. Bucillamine treatment with I/R also increased parenchymal blood flow [red blood cell (RBC) velocity 242.66 +/- 16.86 vs. 181.11 +/- 17.59, at the end of 3 h of reperfusion) and reduced hepatocyte necrosis/apoptosis at 3 h as well as 24 h (P > 0.001).

CONCLUSION

Bucillamine reduces the hepatocellular injury of liver ischaemia reperfusion and improves parenchymal perfusion.

Liver resection versus other treatments for neuroendocrine tumours in patients with resectable liver metastases

BACKGROUND

Neuroendocrine tumours are tumours of cells, which possess secretory granules and originate from the neuroectoderm. While liver resection is generally advocated in patients with resectable liver metastases, recent studies have shown good survival in patients with disseminated neuroendocrine tumours who underwent thermal ablation using radiofrequency.

OBJECTIVES

To determine the benefits and harms of liver resection versus other treatments in patients with resectable liver metastases from gastro-entero-pancreatic neuroendocrine tumours.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded and LILACS until July 2008 for identifying the randomised trials.

SELECTION CRITERIA

We considered only randomised clinical trials (irrespective of language, blinding, or publication status) comparing liver resection (alone or in combination with radiofrequency ablation or cryoablation) versus other interventions (chemotherapy, hormonotherapy, or immunotherapy) and those comparing liver resection and thermal ablation (radiofrequency ablation or cryoablation) in patients with resectable liver metastases from neuroendocrine tumours for the review.

DATA COLLECTION AND ANALYSIS

Two authors independently identified trials for inclusion.

MAIN RESULTS

We were unable to identify any randomised clinical trial suitable for inclusion in this review. We were also unable to identify any quasi-randomised studies, cohort studies, or case-control studies that could inform meaningfully.

AUTHORS' CONCLUSIONS

There is no evidence from randomised clinical trials comparing liver resection versus other treatments in patients with resectable liver metastases from gastro-entero-pancreatic neuroendocrine tumours. Liver resection appears to be the main stay curative treatment for neuroendocrine liver metastases based on non-randomised studies. Further randomised clinical trials comparing liver resection alone or in combination with chemoembolisation or radionuclide therapy are needed. Further randomised clinical trials comparing surgical resection and radiofrequency ablation in selected patients may also be appropriate.

Low pressure versus standard pressure pneumoperitoneum in laparoscopic cholecystectomy

BACKGROUND

A pneumoperitoneum of 12 to 16 mmHg is used for laparoscopic cholecystectomy. Lower pressures are claimed to be safe and effective in decreasing cardiopulmonary complications and pain.

OBJECTIVES

To assess the benefits and harms of low pressure pneumoperitoneum compared with standard pressure pneumoperitoneum in patients undergoing laparoscopic cholecystectomy.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until November 2008 for identifying randomised trials using search strategies.

SELECTION CRITERIA

Only randomised clinical trials, irrespective of language, blinding, or publication status were considered for the review.

DATA COLLECTION AND ANALYSIS

Two authors independently identified trials and independently extracted data on mortality, morbidity, conversion to open cholecystectomy, pain, analgesic requirement, operating time, hospital stay, patient satisfaction, additional measures to increase vision, and cardiopulmonary parameters. We calculated the risk ratio (RR), mean difference (MD), or standardised mean difference (SMD) with 95% confidence intervals (CI) using both the fixed-effect and the random-effects models with RevMan 5 based on available case-analysis.

MAIN RESULTS

Fifteen trials randomised 690 patients to low pressure (n = 336) and standard pressure (n = 354). All the trials were of high risk of bias. There was no difference in the mortality, morbidity, or conversion to open cholecystectomy between the groups. The intensity of pain was lower in the low pressure group at various time points. The incidence of shoulder pain was lower in the low pressure group (RR 0.53; 95% CI 0.31 to 0.90). The analgesic consumption was also lower. The operating time was similar between the groups (MD 2.30 minutes; 95% CI 0.42 to 4.18). Because of the high risk of bias due to incomplete outcome data in seven trials, it was not possible to conclude about the safety of low pressure pneumoperitoneum.

AUTHORS' CONCLUSIONS

Low pressure pneumoperitoneum appears effective in decreasing pain after laparoscopic cholecystectomy. The safety of low pressure pneumoperitoneum has to be established.

Assessment of risk of bias in randomized clinical trials in surgery

BACKGROUND

Meta-analysis of randomized clinical trials (RCTs) with low risk of bias is considered the highest level of evidence available for evaluating an intervention. Bias in RCTs may overestimate or underestimate the true effectiveness of an intervention.

METHODS

The causes of bias in surgical trials as described by The Cochrane Collaboration, and the methods that can be used to avoid them, are reviewed.

RESULTS

Blinding is difficult in many surgical trials but careful trial design can reduce the bias risk due to lack of blinding. It is possible to conduct surgical trials with low risk of bias by using appropriate trial design.

CONCLUSION

The risk of providing a treatment based on a biased effect estimate must be balanced against the difficulty of conducting trials with very low risk of bias. Better understanding of the risk of bias may result in improved trials with a closer estimate of the true effectiveness of an intervention.

Effect of remote ischemic preconditioning on hepatic microcirculation and function in a rat model of hepatic ischemia reperfusion injury

BACKGROUND

Liver transplantation involves a period of ischemia and reperfusion to the graft which leads to primary non-function and dysfunction of the liver in 5-10% of cases. Remote ischemic preconditioning (RIPC) has been shown to reduce ischemia reperfusion injury (IRI) injury to the liver and increase hepatic blood flow. We hypothesized that RIPC may directly modulate hepatic microcirculation and have investigated this using intravital microscopy.

METHODS

A rat model of liver IRI was used with 45 min of partial hepatic ischemia (70%) followed by 3 h of reperfusion. Four groups of animals (Sham, IRI, RIPC+IRI, RIPC+Sham) were studied (n= 6, each group). Intravital microscopy was used to measure red blood cell (RBC) velocity, sinusoidal perfusion, sinusoidal flow and sinusoidal diameter. Neutrophil adhesion was assessed by rhodamine labeling of neutrophils and cell death using propidium iodide.

RESULTS

RIPC reduced the effects of IRI by significantly increasing red blood cell velocity, sinusoidal flow and sinusoidal perfusion along with decreased neutrophil adhesion and cell death.

CONCLUSIONS

Using intravital microscopy, this study demonstrates that RIPC modulates hepatic microcirculation to reduce the effects of IRI. HO-1 may have a key role in the modulation of hepatic microcirculation and endothelial function.

Effect of portal vein embolisation on the growth rate of colorectal liver metastases

Portal vein embolisation (PVE) is used to increase the remnant liver volume before major liver resection for colorectal metastases. The resection rate after PVE is 60-70%, mainly limited by disease progression. The effect of PVE on tumour growth rate has not been investigated. The objective of this study was to compare the growth characteristics of resected colorectal liver metastases in patients undergoing pre-operative PVE with those of matched controls who had not undergone PVE. There were 22 patients who had undergone preoperative PVE and 20 matched controls. Tumour growth rate was calculated by the change in tumour volume (CT/MRI volumetric assessment) from diagnosis to resection. Resected histological specimens were examined by two histopathologists independently for cell differentiation, percentage tumour cell necrosis and mitotic rate. Immunochemical staining with Ki67 was carried out using the MIB-1 monoclonal antibody and quantified using a Glasgow cell-counting graticule. The groups were comparable in demographics, stage of primary disease, volume of liver metastases at presentation and chemotherapy received. The tumour growth rate calculated from imaging was more rapid in the PVE group compared with that in controls (control: 0.05+/-0.25 ml day(-1), PVE: 0.36+/-0.68 ml day(-1), P=0.06). Histology showed no difference in the degree of differentiation, extent of necrosis or apoptosis between the two groups. However, mitotic rate was higher post PVE, as was the proliferation index Ki67 (P=0.04). This study has confirmed that tumour growth rate increased following PVE and that this is related to increased tumour cell division.

Methods of vascular occlusion for elective liver resections

BACKGROUND

Vascular occlusion is used to reduce blood loss during liver resection surgery. Various methods of vascular occlusion have been suggested.

OBJECTIVES

To compare the benefits and harms of different methods of vascular occlusion during elective liver resection.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until August 2008.

SELECTION CRITERIA

We included randomised clinical trials comparing different methods of vascular occlusion during elective liver resections (irrespective of language or publication status).

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trials for inclusion and independently extracted the data. We calculated the risk ratio or mean difference with 95% confidence intervals using fixed-effect and random-effects models based on intention-to-treat or available data analysis.

MAIN RESULTS

Ten trials including 657 patients compared different methods of vascular occlusion. All trials were of high risk of bias. Only one or two trials were included under each comparison. There was no statistically significant differences in mortality, liver failure, or other morbidity between any of the comparisons.Hepatic vascular occlusion does not decrease the blood transfusion requirements. It decreases the cardiac output and increases the systemic vascular resistance. In the comparison between continuous portal triad clamping and intermittent portal triad clamping, four of the five liver failures occurred in patients with chronic liver diseases undergoing the liver resections using continuous portal triad clamping. In the comparison between selective inflow occlusion and portal triad clamping, all four patients with liver failure occurred in the selective inflow occlusion group. There was no difference in any of the other important outcomes in any of the comparisons.

AUTHORS' CONCLUSIONS

In elective liver resection, hepatic vascular occlusion cannot be recommended over portal triad clamping. Intermittent portal triad clamping seems to be better than continuous portal triad clamping at least in patients with chronic liver disease. There is no evidence to support selective inflow occlusion over portal triad clamping. The optimal method of intermittent portal triad clamping is not clear. There is no evidence for any difference between the ischaemic preconditioning followed by vascular occlusion and intermittent vascular occlusion for liver resection in patients with non-cirrhotic livers. Further randomised trials of low risk of bias are needed to determine the optimal technique of vascular occlusion.

Cholecystectomy for suspected gallbladder dyskinesia

BACKGROUND

The optimal treatment for patients with suspected biliary dyskinesia is controversial. Some studies found that cholecystectomy produced symptomatic improvement in patients with gallbladder dyskinesia (diagnosed by low gallbladder ejection fraction) while others found no significant benefit. Some studies have shown that gallbladder ejection fraction can discriminate patients who would benefit from cholecystectomy. Other studies have not confirmed this.

OBJECTIVES

The aim of this review was to compare the benefits and harms of cholecystectomy for patients with suspected gallbladder dyskinesia.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until March 2008.

SELECTION CRITERIA

We considered for inclusion all randomised clinical trials comparing cholecystectomy versus no cholecystectomy on patients with gallbladder dyskinesia.

DATA COLLECTION AND ANALYSIS

We collected the data on the characteristics, methodological quality, mortality, number of patients in whom symptoms were improved or cured from the one identified trial. We planned to analyse the data using the fixed-effect and the random-effects models using RevMan Analysis. For each outcome we planned to calculate the risk ratio (RR) with 95% confidence intervals based on intention-to-treat analysis.

MAIN RESULTS

We included one trial with 21 patients randomised: 11 to cholecystectomy and 10 to control (no cholecystectomy). This trial was considered to be of high risk of bias as patients were not blinded and the procedure-related morbidity was not reported. There was no mortality in either group. All patients in the cholecystectomy group and only one patient in the control group had improvement in symptoms (P = 0.0001) after a mean follow-up period of 33.6 months.

AUTHORS' CONCLUSIONS

The evidence for the benefits and harms of cholecystectomy in gallbladder dyskinesia from randomised clinical trials is based on a single small trial at risk of bias. Further randomised clinical trials with improved bias control are necessary to confirm or reject the promising results.

Palliative cytoreductive surgery versus other palliative treatments in patients with unresectable liver metastases from gastro-entero-pancreatic neuroendocrine tumours

BACKGROUND

Neuroendocrine tumours are tumours of cells which possess secretory granules and originate from the neuroectoderm. While liver resection is generally advocated in patients with resectable liver alone metastases, the management of patients with liver metastases, which cannot be completely resected, is controversial.

OBJECTIVES

To determine if cytoreductive surgery is better than other palliative treatments in patients with liver metastases from gastro-entero-pancreatic neuroendocrine tumours, which cannot be completely resected.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, and LILACS until July 2008 for identifying the randomised trials.

SELECTION CRITERIA

Only randomised clinical trials (irrespective of language, blinding, or publication status) comparing liver resection (alone or in combination with radiofrequency ablation or cryoablation) versus other palliative treatments (chemotherapy or hormone-therapy or immunotherapy) or no treatment in patients with liver metastases from neuroendocrine tumours, which cannot be completely resected, were considered for the review.

DATA COLLECTION AND ANALYSIS

Two authors independently identified trials for inclusion.

MAIN RESULTS

We were unable to identify any randomised clinical trial suitable for inclusion in this review.

AUTHORS' CONCLUSIONS

The literature provides no evidence from randomised clinical trials in order to assess the role of cytoreductive surgery in non-resectable liver metastases from gastro-entero-pancreatic neuroendocrine tumours. High-quality randomised clinical trials may become feasible to perform if their conduct and study design is thoroughly considered in all their practical and methodological aspects. Pilot randomised clinical trials, which can guide the study design of definitive randomised clinical trials, are necessary.

Techniques for liver parenchymal transection in liver resection

BACKGROUND

Blood loss during elective liver resection is one of the main factors affecting the surgical outcome. Different parenchymal transection techniques have been suggested to decrease blood loss.

OBJECTIVES

To assess the benefits and risks of the different techniques of parenchymal transection during liver resections.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded (March 2008).

SELECTION CRITERIA

We considered for inclusion all randomised clinical trials comparing different methods of parenchymal dissection irrespective of the method of vascular occlusion or any other measures used for lowering blood loss.

DATA COLLECTION AND ANALYSIS

Two authors identified the trials and extracted the data on the population characteristics, bias risk, mortality, morbidity, blood loss, transection speed, and hospital stay independently of each other. We calculated the odds ratio (OR), mean difference (MD), or standardised mean difference (SMD) with 95% confidence intervals based on 'interntion-to-treat analysis' or 'available case analysis' using RevMan 5.

MAIN RESULTS

We included seven trials randomising 556 patients. The comparisons include CUSA (cavitron ultrasound surgical aspirator) versus clamp-crush (two trials); radiofrequency dissecting sealer (RFDS) versus clamp-crush (two trials); sharp dissection versus clamp-crush technique (one trial); and hydrojet versus CUSA (one trial). One trial compared CUSA, RFDS, hydrojet, and clamp-crush technique. The infective complications and transection blood loss were greater in the RFDS than clamp-crush. There was no difference in the blood transfusion requirements, intensive therapy unit (ITU) stay, or hospital stay in this comparison. There was no significant differences in the mortality, morbidity, markers of liver parenchymal injury or liver dysfunction, ITU, or hospital stay in the other comparisons. The blood transfusion requirements were lower in the clamp-crush technique than CUSA and hydrojet. There was no difference in the transfusion requirements of clamp-crush technique and sharp dissection. Clamp-crush technique is quicker than CUSA, hydrojet, and RFDS. The transection speed of sharp dissection and clamp-crush technique was not compared. There was no clinically or statistically significant difference in the operating time between sharp dissection and clamp-crush techniques. Clamp-crush technique is two to six times cheaper than the other methods depending upon the number of surgeries performed each year.

AUTHORS' CONCLUSIONS

Clamp-crush technique is advocated as the method of choice in liver parenchymal transection because it avoids special equipment, whereas the newer methods do not seem to offer any benefit in decreasing the morbidity or transfusion requirement.

WITHDRAWN: Methods of vascular occlusion for elective liver resections

BACKGROUND

Vascular occlusion is used to reduce blood loss during liver resection surgery. There is considerable controversy regarding whether vascular occlusion should be used or not during elective liver resections. The method of vascular occlusion employed is also controversial. There is also considerable debate on the role of ischaemic preconditioning before vascular occlusion.

OBJECTIVES

To assess the advantages (decreased blood loss and peri-operative morbidity) and disadvantages (liver dysfunction from ischaemia) of vascular occlusion during liver resections. To compare the advantages (in decreasing blood loss or decreasing ischaemia-reperfusion injury) and disadvantages of different types of vascular occlusion versus total, continuous portal triad clamping.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until March 2007.

SELECTION CRITERIA

We included randomised clinical trials comparing vascular occlusion versus no vascular occlusion during elective liver resections (irrespective of language or publication status). We also included randomised clinical trials comparing the different methods of vascular occlusion and those investigating the role of ischaemic preconditioning in liver resection.

DATA COLLECTION AND ANALYSIS

We collected the data on the characteristics of the trial, methodological quality of the trials, mortality, morbidity, blood loss, blood transfusion requirements, liver function tests, markers of neutrophil activation, operating time, and hospital stay. We analysed the data with both the fixed-effect and the random-effects models using RevMan Analysis. For each binary outcome we calculated the odds ratio (OR) with 95% confidence intervals (CI) based on intention-to-treat analysis. For continuous outcomes, we calculated the weighted mean difference (WMD) with 95% confidence intervals.

MAIN RESULTS

We identified a total of 16 randomised trials. Five trials including 331 patients compared vascular occlusion (n = 166) versus no vascular occlusion (n = 165). Six trials including 521 patients compared different methods of vascular occlusion. Three trials including 210 patients compared ischaemic preconditioning before continuous portal triad clamping (n = 105) versus no ischaemic preconditioning (n = 105). Two trials including 127 patients compared ischaemic preconditioning before continuous portal triad clamping (n = 63) versus intermittent portal triad clamping (n = 64).The blood loss was significantly lower in vascular occlusion compared with no vascular occlusion. The liver enzymes were significantly elevated in the vascular occlusion group compared with no vascular occlusion. There was no difference in the mortality, liver failure, or other morbidities. Four of the five trials comparing vascular occlusion and no vascular occlusion used intermittent vascular occlusion. Trials comparing complete inflow and outflow occlusion to the liver, ie, hepatic vascular exclusion and portal triad clamping demonstrate significant detrimental haemodynamic changes in hepatic vascular exclusion compared to portal triad clamping. There was no significant difference in the number of units transfused and the number of patients needing transfusion. There was no difference in mortality, liver failure, or morbidity between total and selective methods of portal triad clamping. All four cases of mortality and liver failure in the comparison between the intermittent and continuous portal triad clamping occurred in the continuous portal triad clamping (statistically not significant). Intermittent portal triad clamping does not increase the total blood loss or operating time compared to continuous portal triad clamping.There was no statistically significant difference in the mortality, liver failure, morbidity, blood loss, or haemodynamic changes between ischaemic preconditioning versus no ischaemic preconditioning before continuous portal triad clamping. Liver enzymes used as markers of liver injury were significantly lower in the early post-operative period in the ischaemic preconditioning group. The intensive therapy unit stay and hospital stay were statistically significantly lower in the ischaemic preconditioning group than in the no ischaemic preconditioning group.There was no statistically significant difference in the mortality, liver failure, morbidity, intensive therapy unit stay, or hospital stay between ischaemic preconditioning before continuous portal triad clamping and intermittent portal triad clamping. The blood loss and transfusion requirements were lower in the ischaemic preconditioning group. Aspartate aminotransferase level was lower in the intermittent portal triad clamping group than the ischaemic preconditioning group on the third post-operative day. There was no difference in the peak aspartate aminotransferase levels or in the aspartate aminotransferase levels on first or sixth post-operative days of aspartate aminotransferase .

AUTHORS' CONCLUSIONS

Intermittent vascular occlusion seems safe in liver resection. However, it does not seem to decrease morbidity. Among the different methods of vascular occlusion, intermittent portal triad clamping has most evidence to support the clinical application. Hepatic vascular exclusion cannot be recommended routinely. Ischaemic preconditioning before continuous portal triad clamping may be of clinical benefit in reducing intensive therapy unit and hospital stay.

Antiviral therapy for recurrent liver graft infection with hepatitis C virus

BACKGROUND

Antiviral therapy to treat recurrent hepatitis C infection after liver transplantation is controversial.

OBJECTIVES

To compare the therapeutic efficacy and side effects of different antiviral regimens in patients with hepatitis C re-infected grafts after liver transplantation.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until September 2007.

SELECTION CRITERIA

Only randomised clinical trials (irrespective of language, blinding, or publication status) comparing various antiviral therapies (alone or in combination) in the treatment of hepatitis C virus recurrence in liver transplantation were considered for the review.

DATA COLLECTION AND ANALYSIS

Two authors collected the data independently. We calculated the relative risk (RR) or weighted mean difference (WMD) with 95% confidence intervals (CI) using the fixed-effect and the random-effects models based on available case-analysis.

MAIN RESULTS

A total of 389 liver transplant recipients with proven hepatitis C recurrence were randomised in eleven trials to various interventions and controls. The mean proportion of genotype I was 77.8% in the seven trials that reported the genotype. Only one or two trials were included under each comparison. All the trials were of high risk of bias. There was no difference in the mortality, graft rejection, or in re-transplantation between intervention and control in any of the comparisons that reported these outcomes. None of the trials reported liver decompensation or quality of life. Life-threatening adverse effects were not reported in either group in any of the comparisons. Up to 87.5% of patients required reduction in dose and up to 42.9% of patients required cessation of treatment in the various comparisons because of adverse effects or because of patient's choice to stop treatment.

AUTHORS' CONCLUSIONS

1. Considering the lack of clinical benefit and the frequent adverse effects, there is currently no evidence to recommend antiviral treatment for recurrent liver graft infection with HCV. 2. Further randomised clinical trials with adequate trial methodology and adequate duration of follow-up are necessary.

Vascular occlusion for elective liver resections

BACKGROUND

Vascular occlusion is used to reduce blood loss during liver resection. There is considerable controversy regarding whether vascular occlusion should be used or not during elective liver resections.

OBJECTIVES

To assess the advantages (decreased blood loss and peri-operative morbidity) and disadvantages (ischaemia-reperfusion injury related complications like liver dysfunction) of vascular occlusion during elective liver resections.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until August 2008.

SELECTION CRITERIA

We included randomised clinical trials comparing vascular occlusion versus no vascular occlusion during elective liver resections (irrespective of language or publication status).

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trials for inclusion and independently extracted the data. We analysed the data with both the fixed-effect and the random-effects models using RevMan Analysis. We calculated the risk ratio (RR), mean difference (MD), or standardised mean difference (SMD) with 95% confidence intervals (CI) based on intention-to-treat or available case analysis.

MAIN RESULTS

We identified a total of five trials (of high bias-risk) which compared vascular occlusion (n = 166) versus no vascular occlusion (n = 165). Three of the five trials comparing vascular occlusion and no vascular occlusion used intermittent vascular occlusion. There was no difference in mortality, liver failure, or other morbidities. The blood loss was significantly lower in vascular occlusion compared with no vascular occlusion. The liver enzymes were significantly elevated in the vascular occlusion group compared with no vascular occlusion.

AUTHORS' CONCLUSIONS

Intermittent vascular occlusion seems safe in liver resection. However, it does not seem to decrease morbidity. More randomised trials seem to be needed.

Ischaemic pre-conditioning for elective liver resections performed under vascular occlusion

BACKGROUND

Vascular occlusion is used to reduce blood loss during liver resection surgery. The enzyme markers of liver injury are elevated if vascular occlusion is employed during liver resection. It is not clear whether ischaemic preconditioning prior to vascular occlusion has a protective effect during elective liver resections.

OBJECTIVES

To assess the advantages (decreased ischaemia-reperfusion injury) and any potential disadvantages of ischaemic preconditioning prior to vascular occlusion during liver resections.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until August 2008.

SELECTION CRITERIA

We included randomised clinical trials comparing ischaemic preconditioning versus no ischaemic preconditioning prior to vascular occlusion (irrespective of the method of vascular occlusion) during elective liver resections (irrespective of language or publication status).

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trials for inclusion and independently extracted the data. We analysed the data with both the fixed-effect and the random-effects models using RevMan Analysis. We calculated the risk ratio, mean difference, or standardised mean difference with 95% confidence intervals based on intention-to-treat or available data analysis.

MAIN RESULTS

We included four trials with 271 patients undergoing open liver resections. The patients were randomised to ischaemic preconditioning (n = 135) and no ischaemic preconditioning (n = 136) prior to continuous vascular occlusion (portal triad clamping in three trials and hepatic vascular exclusion in one trial). All the trials excluded cirrhotic patients. We assessed all the four trials as having high risk of bias. There was no difference in mortality, liver failure, other peri-operative morbidity, hospital stay, intensive therapy unit stay, and operating time between the two groups. The proportion of patients requiring blood transfusion was lower in the ischaemic preconditioning group. There was also a trend towards a lower amount of red cell transfusion favouring ischaemic preconditioning group. There was no difference in the haemodynamic changes, blood loss, bilirubin, or prothrombin activity between the two groups. The enzyme markers of liver injury were lower in the ischaemic preconditioning group on the first post-operative day.

AUTHORS' CONCLUSIONS

Currently, there is no evidence to suggest a protective effect of ischaemic preconditioning in non-cirrhotic patients undergoing liver resection under continuous vascular occlusion. Ischaemic preconditioning reduces the blood transfusion requirements in patients undergoing liver resection.

Virtual reality training for surgical trainees in laparoscopic surgery

BACKGROUND

Surgical training has traditionally been one of apprenticeship, where the surgical trainee learns to perform surgery under the supervision of a trained surgeon. This is time consuming, costly, and of variable effectiveness. Training using a virtual reality simulator is an option to supplement standard training.

OBJECTIVES

To determine whether virtual reality training can supplement or replace conventional laparoscopic surgical training (apprenticeship) in surgical trainees with limited or no prior laparoscopic experience.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, and grey literature until March 2008.

SELECTION CRITERIA

We included all randomised clinical trials comparing virtual reality training versus other forms of training including video trainer training, no training, or standard laparoscopic training in surgical trainees with little or no prior laparoscopic experience. We also included trials comparing different methods of virtual reality training.

DATA COLLECTION AND ANALYSIS

We collected the data on the characteristics of the trial, methodological quality of the trials, mortality, morbidity, conversion rate, operating time, and hospital stay. We analysed the data with both the fixed-effect and the random-effects models using RevMan Analysis. For each outcome we calculated the standardised mean difference with 95% confidence intervals based on intention-to-treat analysis.

MAIN RESULTS

We included 23 trials with 612 participants. Four trials compared virtual reality versus video trainer training. Twelve trials compared virtual reality versus no training or standard laparoscopic training. Four trials compared virtual reality, video trainer training and no training, or standard laparoscopic training. Three trials compared different methods of virtual reality training. Most of the trials were of high risk of bias. In trainees without prior surgical experience, virtual reality training decreased the time taken to complete a task, increased accuracy, and decreased errors compared with no training; virtual reality group was more accurate than video trainer training group. In the participants with limited laparoscopic experience, virtual reality training reduces operating time and error better than standard in the laparoscopic training group; composite operative performance score was better in the virtual reality group than in the video trainer group.

AUTHORS' CONCLUSIONS

Virtual reality training can supplement standard laparoscopic surgical training of apprenticeship and is at least as effective as video trainer training in supplementing standard laparoscopic training. Further research of better methodological quality and more patient-relevant outcomes are needed.

Cholecystectomy for gallbladder polyp

BACKGROUND

The management of gallbladder polyps is controversial. Cholecystectomy has been recommended for gallbladder polyps larger than 10 mm because of the association with gallbladder cancer. Cholecystectomy has also been suggested for gallbladder polyps smaller than 10 mm in patients with biliary type of symptoms.

OBJECTIVES

The aim of this review is to compare the benefits (relief of symptoms, decreased incidence of gallbladder cancer) and harms (surgical morbidity) of cholecystectomy in patients with gallbladder polyp(s).

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until July 2008 to identify the randomised trials.

SELECTION CRITERIA

Only randomised clinical trials (irrespective of language, blinding, or publication status) comparing cholecystectomy and no cholecystectomy were considered for the review.

DATA COLLECTION AND ANALYSIS

We planned to collect the data on the characteristics, methodological quality, mortality, number of patients in whom symptoms were improved or cured from the one identified trial. We planned to analyse the data using the fixed-effect and the random-effects models using RevMan Analysis. For each outcome we planned to calculate the risk ratio (RR) with 95% confidence intervals based on intention-to-treat analysis.

MAIN RESULTS

We were unable to identify any randomised clinical trials comparing cholecystectomy versus no cholecystectomy in patients with a gallbladder polyp.

AUTHORS' CONCLUSIONS

There are no randomised trials comparing cholecystectomy versus no cholecystectomy in patients with gallbladder polyps. Randomised clinical trials with low bias -risk are necessary to address the question of whether cholecystectomy is indicated in gallbladder polyps smaller than10 mm.

Virtual reality training for surgical trainees in laparoscopic surgery

BACKGROUND

Surgical training has traditionally been one of apprenticeship, where the surgical trainee learns to perform surgery under the supervision of a trained surgeon. This is time consuming, costly, and of variable effectiveness. Training using a virtual reality simulator is an option to supplement standard training.

OBJECTIVES

To determine whether virtual reality training can supplement or replace conventional laparoscopic surgical training (apprenticeship) in surgical trainees with limited or no prior laparoscopic experience.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, and grey literature until March 2008.

SELECTION CRITERIA

We included all randomised clinical trials comparing virtual reality training versus other forms of training including video trainer training, no training, or standard laparoscopic training in surgical trainees with little or no prior laparoscopic experience. We also included trials comparing different methods of virtual reality training.

DATA COLLECTION AND ANALYSIS

We collected the data on the characteristics of the trial, methodological quality of the trials, mortality, morbidity, conversion rate, operating time, and hospital stay. We analysed the data with both the fixed-effect and the random-effects models using RevMan Analysis. For each outcome we calculated the standardised mean difference with 95% confidence intervals based on intention-to-treat analysis.

MAIN RESULTS

We included 23 trials with 612 participants. Four trials compared virtual reality versus video trainer training. Twelve trials compared virtual reality versus no training or standard laparoscopic training. Four trials compared virtual reality, video trainer training and no training, or standard laparoscopic training. Three trials compared different methods of virtual reality training. Most of the trials were of high risk of bias. In trainees without prior surgical experience, virtual reality training decreased the time taken to complete a task, increased accuracy, and decreased errors compared with no training; virtual reality group was more accurate than video trainer training group. In the participants with limited laparoscopic experience, virtual reality training reduces operating time and error better than standard in the laparoscopic training group; composite operative performance score was better in the virtual reality group than in the video trainer group.

AUTHORS' CONCLUSIONS

Virtual reality training can supplement standard laparoscopic surgical training of apprenticeship and is at least as effective as video trainer training in supplementing standard laparoscopic training. Further research of better methodological quality and more patient-relevant outcomes are needed.

Robot assistant for laparoscopic cholecystectomy

BACKGROUND

The role of a robotic assistant in laparoscopic cholecystectomy is controversial. While some trials have shown distinct advantages of robotic assistant over a human assistant, others have not, and it is unclear which robotic assistant is best.

OBJECTIVES

The aims of this review are to compare the safety of robot assistant versus human assistant in laparoscopic cholecystectomy and to assess whether the robot can substitute for the human assistant.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until May 2008 for identifying the randomised trials using The Cochrane Hepato-Biliary Group search strategy.

SELECTION CRITERIA

Only randomised clinical trials (irrespective of language, blinding, or publication status) comparing robot assistants versus human assistants in laparoscopic cholecystectomy were considered for the review. Randomised clinical trials comparing different types of robot assistants were also considered for the review.

DATA COLLECTION AND ANALYSIS

Two authors independently identified the trials for exclusion and independently extracted the data. We calculated the risk ratio, mean difference, or standardised mean difference with 95% confidence intervals using the fixed-effect and the random-effects models based on available case-analysis using RevMan 5.

MAIN RESULTS

We included five trials (all of high risk of bias) with 453 patients randomised: 159 to the robot-assistant group and 165 to the human assistant group (one trial report of 129 patients was a conference abstract, not reporting on the number of patients in each group). There was no statistically significant difference between the two groups for morbidity, conversion to open cholecystectomy, total operating time, or hospital stay when fixed-effect or random-effects model were used. The instrument set-up time was significantly lower in the human assistant group. In one trial, about one sixth of the laparoscopic cholecystectomies in which robot assistant was used, required temporary use of a human assistant. It appears that there was little or no requirement for human assistants in the other three published trials. In two of the three trials, which reported surgeons' preference, the surgeons preferred a robot assistant to a human assistant. There was no statistically significant difference in the accuracy when the random-effects model was used. There was no difference in the errors.

AUTHORS' CONCLUSIONS

Although robot-assisted laparoscopic cholecystectomy appears safe, there seems to be no significant advantages over human-assisted laparoscopic cholecystectomy. We were unable to identify trials comparing one type of robot assistant versus another. Further randomised trials with low bias-risk and random errors are needed.

Serum C-reactive protein concentration and the prognosis of ductal adenocarcinoma of the head of pancreas

BACKGROUND

The prognostic role of serum C-reactive protein in pancreatic cancer has received increasing attention; however the confounding effects of biliary obstruction have not been addressed in previous studies. We sought to determine the prognostic importance of serum CRP prior to biliary intervention in the prognosis of pancreatic adenocarcinoma.

METHODS

A retrospective case note review of patients diagnosed with pancreatic cancer between 2001 and 2006. Clinical, radiological and biochemical criteria were correlated with overall survival. Patients were divided into: Group 1 who underwent potentially curative resection, and Group 2 with advanced unresectable disease managed non-surgically.

RESULTS

In total, 199 patients were included (58 resected). The proportion of patients with biliary obstruction was equal in both groups. Serum CRP and serum bilirubin concentration at presentation were significantly higher among patients in Group 2 compared to Group 1 (P values). On multivariate analysis, advancing age (P=0.012) and raised serum CRP concentration were independently associated with overall survival only in Group 2 patients (P=0.027, 95% CI 0.31-0.93). This association was independent of biliary tract obstruction.

CONCLUSION

Raised serum C-reactive protein concentration at the time of presentation of advanced pancreatic cancer carries a poor prognosis independent of biliary tract obstruction.

A Meta-Analysis of the Impact of the Two-Layer Method of Preservation on Human Pancreatic Islet Transplantation

There are conflicting reports about the effectiveness of perfluorocarbons used in the two-layer method (TLM) of pancreas preservation for human islet transplantation. The mechanism of action is unclear and the optimal role of this method uncertain. The study design was a meta-analysis of the evidence that TLM improves islet isolation outcomes. Pubmed, CENTRAL, EMBASE, Science Citation Index, and BIOSIS were searched electronically in January 2008. After selecting the relevant human trials for meta-analysis data relating to donor variables, study design, primary and secondary islet isolation outcomes were extracted. Electronic searches identified eight unique citations, describing 11 human studies that were eligible for the meta-analysis. When comparing TLM with preservation in University of Wisconsin (UW) solution, there was a statistically significant higher islet yield [WMD 711.55, 95% confidence interval (CI) 140.03–1283.07] in the TLM group. The proportion of transplantable preparations obtained was not significantly different (OR 1.30, 95% CI 0.89–1.88) between the two groups. The rate of successful islet isolations for marginal organs was higher in the TLM group (OR 6.69, 95% CI 1.80–24.87). Improved oxygenation and preservation of cellular bioengertics is thought to be the main underlying mechanism, although no single mechanism has yet been confirmed. There is currently no clear evidence that the TLM is beneficial in human islet transplantation. It may improve the preservation of marginal organs.

Prospective evaluation of two-stage hepatectomy combined with selective portal vein embolisation and systemic chemotherapy for patients with unresectable bilobar colorectal liver metastases

BACKGROUND

Liver resection is contraindicated in patients with multiple bilobar colorectal liver metastases because of the small liver remnant. An alternative strategy which may be curative is a two-stage hepatectomy in which the cancer is resected from one lobe and regeneration allowed prior to contralateral lobe resection.

OBJECTIVE

To assess the feasibility, risks, and outcomes in a prospectively applied strategy for two-stage hepatectomy.

METHODS

Over a 6-year period, 14 of 280 patients undergoing liver resection for colorectal liver metastases (5%) were considered for two-stage hepatectomy. Surgery was combined with chemotherapy in all (n = 14) and portal vein embolisation (PVE) selectively (n = 5). Median follow-up was 43 months.

RESULTS

Both stages were completed in 11 of 14 patients (78%). There were no deaths. Post-operative complication rates were 0% (1st hepatectomy) and 27% (2nd hepatectomy). The 5-year survival after the second hepatectomy was 50%. The mean disease-free survival was 25 +/- 7.5 months.

CONCLUSION

Two-stage hepatectomy combined with systemic chemotherapy and PVE can produce long-term survival in patients with multiple bilobar colorectal liver metastases.

Mirizzi syndrome associated with hepatic artery pseudoaneurysm: a case report

Introduction

This is the first case report of Mirizzi syndrome associated with hepatic artery pseudoaneurysm.

Case presentation

A 54-year-old man presented with painful obstructive jaundice and weight loss. Computed tomography showed a hilar mass in the liver. Following an episode of haemobilia, angiography demonstrated a pseudoaneurysm of a branch of the right hepatic artery that was embolised. At surgery, a gallstone causing Mirizzi type II syndrome was found to be responsible for the biliary obstruction and a necrotic inflammatory mass and haematoma were found to be extending into the liver. The mass was debrided and drained, the obstructing stones removed and the bile duct drained with a t-tube. The patient made a full recovery.

Conclusion

This case highlights another situation where there may be difficulty in differentiating Mirizzi syndrome from biliary tract cancer.

Early versus delayed laparoscopic cholecystectomy for biliary colic

BACKGROUND

Biliary colic is one of the commonest indications for laparoscopic cholecystectomy. Laparoscopic cholecystectomy involves several months of waiting if performed electively. However, patients can develop life-threatening complications during this waiting period.

OBJECTIVES

To assess the benefits and harms of early versus delayed laparoscopic cholecystectomy for patients with biliary colic due to gallstones.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until March 2008.

SELECTION CRITERIA

We included only randomised clinical trials irrespective of language and publication status.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the data. We intended to calculate the risk ratio, risk difference with 95% confidence intervals (CI) for dichotomous outcomes, and weighted mean difference (WMD) with 95% CI for continuous outcomes using RevMan 4.2 based on intention-to-treat analysis.

MAIN RESULTS

Only one trial including 75 patients, randomised to early laparoscopic cholecystectomy (less than 24 hours of diagnosis) (n = 35) and delayed laparoscopic cholecystectomy (mean waiting period of 4.2 months) (n = 40), qualified for this review. This trial was of high risk of bias. During the waiting period in the delayed group (mean 4.2 months), the complications that the patients suffered included severe acute pancreatitis resulting in mortality (1), empyema of gallbladder (1), gallbladder perforation (1), acute cholecystitis (2), cholangitis (2), obstructive jaundice (2), and recurrent biliary colic requiring hospital visits (5). The rate of conversion to open cholecystectomy was lower in the early group (0%) than the delayed group (8/40 or 20%) (p = 0.0172). There was a statistically significant shorter operating time and hospital stay in the early group than the delayed group (WMD -14.80 minutes, 95% CI -18.02 to -11.58 and -1.25 days, 95% CI -2.05 to -0.45 respectively). Fourteen patients (35%) required 18 hospital admissions for symptoms related to gallstones during the mean waiting period of 4.2 months in the delayed group. This is equivalent to 11 admissions per 100 persons per month.

AUTHORS' CONCLUSIONS

Based on evidence from only one high-bias risk trial, it appears that early laparoscopic cholecystectomy (< 24 hours of diagnosis of biliary colic) decreases the morbidity during the waiting period for elective laparoscopic cholecystectomy, decreases the rate of conversion to open cholecystectomy, decreases operating time, and decreases hospital stay. Further randomised clinical trials are necessary to confirm or refute this finding.