Comparison of manual and semi-automatic registration in augmented reality image-guided liver surgery: a clinical feasibility study.

BACKGROUND: The laparoscopic approach to liver resection may reduce morbidity and hospital stay. However, uptake has been slow due to concerns about patient safety and oncological radicality. Image guidance systems may improve patient safety by enabling 3D visualisation of critical intra- and extrahepatic structures. Current systems suffer from non-intuitive visualisation and a complicated setup process. A novel image guidance system (SmartLiver), offering augmented reality visualisation and semi-automatic registration has been developed to address these issues. A clinical feasibility study evaluated the performance and usability of SmartLiver with either manual or semi-automatic registration. METHODS: Intraoperative image guidance data were recorded and analysed in patients undergoing laparoscopic liver resection or cancer staging. Stereoscopic surface reconstruction and iterative closest point matching facilitated semi-automatic registration. The primary endpoint was defined as successful registration as determined by the operating surgeon. Secondary endpoints were system usability as assessed by a surgeon questionnaire and comparison of manual vs. semi-automatic registration accuracy. Since SmartLiver is still in development no attempt was made to evaluate its impact on perioperative outcomes. RESULTS: The primary endpoint was achieved in 16 out of 18 patients. Initially semi-automatic registration failed because the IGS could not distinguish the liver surface from surrounding structures. Implementation of a deep learning algorithm enabled the IGS to overcome this issue and facilitate semi-automatic registration. Mean registration accuracy was 10.9 ± 4.2 mm (manual) vs. 13.9 ± 4.4 mm (semi-automatic) (Mean difference - 3 mm; p = 0.158). Surgeon feedback was positive about IGS handling and improved intraoperative orientation but also highlighted the need for a simpler setup process and better integration with laparoscopic ultrasound. CONCLUSION: The technical feasibility of using SmartLiver intraoperatively has been demonstrated. With further improvements semi-automatic registration may enhance user friendliness and workflow of SmartLiver. Manual and semi-automatic registration accuracy were comparable but evaluation on a larger patient cohort is required to confirm these findings.

Cost-effectiveness of noninvasive liver fibrosis tests for treatment decisions in patients with chronic hepatitis B in the UK: systematic review and economic evaluation.

We compared the cost-effectiveness of various noninvasive tests (NITs) in patients with chronic hepatitis B and elevated transaminases and/or viral load who would normally undergo liver biopsy to inform treatment decisions. We searched various databases until April 2012. We conducted a systematic review and meta-analysis to calculate the diagnostic accuracy of various NITs using a bivariate random-effects model. We constructed a probabilistic decision analytical model to estimate health care costs and outcomes quality-adjusted-life-years (QALYs) using data from the meta-analysis, literature, and national UK data. We compared the cost-effectiveness of four decision-making strategies: testing with NITs and treating patients with fibrosis stage ≥F2, testing with liver biopsy and treating patients with ≥F2, treat none (watchful waiting) and treat all irrespective of fibrosis. Treating all patients without prior fibrosis assessment had an incremental cost-effectiveness ratio (ICER) of £28,137 per additional QALY gained for HBeAg-negative patients. For HBeAg-positive patients, using Fibroscan was the most cost-effective option with an ICER of £23,345. The base case results remained robust in the majority of sensitivity analyses, but were sensitive to changes in the ≥ F2 prevalence and the benefit of treatment in patients with F0-F1. For HBeAg-negative patients, strategies excluding NITs were the most cost-effective: treating all patients regardless of fibrosis level if the high cost-effectiveness threshold of £30,000 is accepted; watchful waiting if not. For HBeAg-positive patients, using Fibroscan to identify and treat those with ≥F2 was the most cost-effective option.

Transcranial Doppler Ultrasound Detection of Microemboli as a Predictor of Cerebral Events in Patients with Symptomatic and Asymptomatic Carotid Disease: A Systematic Review and Meta-Analysis.

OBJECTIVE: Identification of patients who will benefit from carotid endarterectomy is not entirely effective, primarily utilising degree of carotid stenosis. This study aimed at determining if microembolic signals (MES) detected by transcranial Doppler ultrasound (TCD) can provide clinically useful information regarding stroke risk in patients with carotid atherosclerosis. METHODS: A meta-analysis of prospective studies was performed. Three analyses were proposed investigating MES detection as a predictor of: stroke or TIA, stroke alone, and stroke or TIA but with an increased positivity threshold. Subgroup analysis was used to compare pre-operative (symptomatic or asymptomatic) patients and peri- or post-operative patients. RESULTS: Twenty-eight studies reported data regarding both MES status and neurological outcome. Of these, 22 papers reported data on stroke and TIA as an outcome, 19 on stroke alone, and eight on stroke and TIA with increased positivity threshold. At the median pre-test probability of 3.0%, the post-test probabilities of a stroke after a positive and negative TCD were 7.1% (95% CI 5-10.1) and 1.2% (95% CI 0.6-2.5), respectively. In addition, the sensitivities and specificities of each outcome showed that increasing the threshold for positivity to 10 MES per hour would make TCD a more clinically useful tool in peri- and post-operative patients. CONCLUSION: TCD provides clinically useful information about stroke risk for patients with carotid disease and is technically feasible in most patients. However, the generally weak level of evidence constituting this review means definitive recommendations cannot be made.

Cost-effectiveness of early laparoscopic cholecystectomy for mild acute gallstone pancreatitis.

BACKGROUND: A recent Cochrane review suggested that laparoscopic cholecystectomy carried out early following mild gallstone pancreatitis was safe. This study compared the cost-effectiveness of laparoscopic cholecystectomy performed within 3 days of admission, during the same admission but after more than 3 days, or electively in a subsequent admission. METHODS: A model-based cost-utility analysis was performed estimating mean costs and quality-adjusted life-years (QALYs) per patient in the UK National Health Service with a 1-year time horizon. A decision tree model was constructed and populated with probabilities, outcomes and cost data from published sources for mild gallstone pancreatitis, including one-way and probabilistic sensitivity analyses. RESULTS: The costs of laparoscopic cholecystectomy performed within 3 days of admission, beyond 3 days but in the same admission, and electively in a subsequent admission were € 2748, € 3543 and € 3752 respectively; the QALYs were 0.888, 0.888 and 0.884 respectively. Early laparoscopic cholecystectomy had a 91 per cent probability of being cost-effective at the maximum willingness to pay for a QALY commonly used in the UK. It is acknowledged that many hospitals do not have access to magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography, especially at weekends, and that implementing a 3-day target is unrealistic without allocating new resources that could erode the cost-effectiveness. CONCLUSION: Performing laparoscopic cholecystectomy for mild gallstone pancreatitis within 3 days of admission is cost-effective, but may not be feasible without significant resource allocation. After 3 days there is little financial advantage to same-admission operation.

A comparison of total intravenous anaesthesia using propofol with sevoflurane or desflurane in ambulatory surgery: systematic review and meta-analysis.

With the popularity of ambulatory surgery ever increasing, we carried out a systematic review and meta-analysis to determine whether the type of anaesthesia used had any bearing on patient outcomes. Total intravenous propofol anaesthesia was compared with two of the newer inhalational agents, sevoflurane and desflurane. In total, 18 trials were identified; only trials where nitrous oxide was administered to, or omitted from, both groups were included. A total of 1621 patients were randomly assigned to either propofol (685 patients) or inhalational anaesthesia (936 patients). If surgical causes of unplanned admissions were excluded, there was no difference in unplanned admission to hospital between propofol and inhalational anaesthesia (1.0% vs 2.9%, respectively; p = 0.13). The incidence of postoperative nausea and vomiting was lower with propofol than with inhalational agents (13.8% vs 29.2%, respectively; p < 0.001). However, no difference was noted in post-discharge nausea and vomiting (23.9% vs 20.8%, respectively; p = 0.26). Length of hospital stay was shorter with propofol, but the difference was only 14 min on average. The use of propofol was also more expensive, with a mean (95% CI) difference of £6.72 (£5.13-£8.31 (€8.16 (€6.23-€10.09); $11.29 ($8.62-$13.96))) per patient-anaesthetic episode (p < 0.001). Therefore, based on the published evidence to date, maintenance of anaesthesia using propofol appeared to have no bearing on the incidence of unplanned admission to hospital and was more expensive, but was associated with a decreased incidence of early postoperative nausea and vomiting compared with sevoflurane or desflurane in patients undergoing ambulatory surgery.

Meta-analysis of randomized clinical trials on safety and efficacy of biliary drainage before surgery for obstructive jaundice.

BACKGROUND: This meta-analysis aimed to investigate whether preoperative biliary drainage (PBD) is beneficial to patients with obstructive jaundice. METHODS: Data from randomized clinical trials related to safety and effectiveness of PBD versus no PBD were extracted by two independent reviewers. Risk ratios, rate ratios or mean differences were calculated with 95 per cent confidence intervals (c.i.), based on intention-to-treat analysis, whenever possible. RESULTS: Six trials (four using percutaneous transhepatic biliary drainage and two using endoscopic sphincterotomy) including 520 patients with malignant or benign obstructive jaundice comparing PBD (265 patients) with no PBD (255) were included in this review. All trials had a high risk of bias. There was no significant difference in mortality (risk ratio 1.12, 95 per cent c.i. 0.73 to 1.71; P = 0.60) between the two groups. Overall serious morbidity (grade III or IV, Clavien-Dindo classification) was higher in the PBD group (599 complications per 1000 patients) than in the direct surgery group (361 complications per 1000 patients) (rate ratio 1.66, 95 per cent c.i. 1.28 to 2.16; P < 0.001). Quality of life was not reported in any of the trials. There was no significant difference in length of hospital stay between the two groups: mean difference 4.87 (95 per cent c.i. -1.28 to 11.02) days (P = 0.12). CONCLUSION: PBD in patients undergoing surgery for obstructive jaundice is associated with similar mortality but increased serious morbidity compared with no PBD. Therefore, PBD should not be used routinely.

Fenestrated endovascular aneurysm repair.

BACKGROUND: Fenestrated endovascular aneurysm repair (FEVAR) is a technically challenging operation. The duration, blood loss, and risk of limb ischaemia, contrast-induced nephropathy and reperfusion injury are likely to be higher than after standard endovascular aneurysm repair (EVAR). Benefits of FEVAR over open repair may be less than those seen with standard infrarenal EVAR. This paper is a meta-analysis of observational studies of all published data for FEVAR, with the aim to highlight current issues around the evidence for the potential benefit of FEVAR. METHODS: A search was performed for studies describing FEVAR for juxtarenal abdominal aortic aneurysms. Small series of fewer than ten procedures and studies describing predominantly branched endografts or FEVAR for aortic dissection were excluded. Authors of included papers were contacted to eliminate patient duplication. RESULTS: Eleven studies were identified describing a total of 660 procedures. Definitions of aneurysm morphology were variable, and clear inclusion and exclusion criteria were not always documented. Double fenestrations were more common than triple or quadruple fenestrations. Target vessel perfusion rates ranged from 90·5 to 100 per cent. Eleven deaths occurred within 30 days, giving a 30-day proportional mortality rate of 2·0 per cent. Morbidity was poorly reported. CONCLUSION: FEVAR for repair of suprarenal and juxtarenal aneurysms is a viable alternative to open repair. However, there is no level 1 evidence for FEVAR, and current evidence is weak with many unanswered questions.

Paracetamol for patent ductus arteriosus in preterm infants: a UK national survey.

INTRODUCTION: Evidence is emerging that paracetamol is a safe and effective alternative therapy for haemodynamically significant patent ductus arteriosus (hsPDA). Although there is no consensus opinion on its routine use for PDA in preterm infants, paracetamol is being used increasingly in many centres to treat hsPDA. OBJECTIVE: We conducted a national survey to review the current practice in the UK and the prevalence of paracetamol use for hsPDA closure in preterm infants. METHOD: A web-based and telephone survey on the use of paracetamol for hsPDA closure in preterm infants was conducted. All neonatal intensive care and local neonatal units across the UK were contacted between May and August 2018. RESULTS: 98% (143/146) neonatal units responded. The first-line medication for hsPDA closure was ibuprofen in 92% (131/143) units. 33% (47/143) of units used paracetamol; three units used it as first-line. The dose and duration of paracetamol varied greatly among the units with a dose of 15 mg/kg 6 hourly in 62% (29/47) units and a duration of 3 and 5 days in 33% (14/42) and 31% (13/42) of units, respectively. 44% (19/43) of units did routine blood investigations using paracetamol for monitoring patients on treatment and 21% (9/43) took paracetamol level in addition to other tests. CONCLUSION: 33% of the neonatal units across the UK offered paracetamol to treat hsPDA in preterm infants. Currently, there is a variation in practice regarding the dose, duration of paracetamol and monitoring of infants during its use for hsPDA closure. One strategy would be to develop national guidance once strong evidence is established to support its routine use for hsPDA in preterm infants.

Elastography for the diagnosis of severity of fibrosis in chronic liver disease: a meta-analysis of diagnostic accuracy.

BACKGROUND & AIMS: Transient elastography is a non-invasive method, for the assessment of hepatic fibrosis, developed as an alternative to liver biopsy. We studied the performance of elastography for diagnosis of fibrosis using meta-analysis. METHODS: MEDLINE, EMBASE, SCI, Cochrane Library, conference abstracts books, and article references were searched. We included studies using biopsy as a reference standard, with the data necessary to calculate the true and false positive, true and false negative diagnostic results of elastography for a fibrosis stage, and with a 3-month maximum interval between tests. The quality of the studies was rated with the QUADAS tool. RESULTS: We identified 40 eligible studies. Summary sensitivity and specificity was 0.79 (95% CI 0.74-0.82) and 0.78 (95% CI 0.72-0.83) for F2 stage and 0.83 (95% CI 0.79-0.86) and 0.89 (95% CI 0.87-0.91) for cirrhosis. After an elastography result at/over the threshold value for F2 or cirrhosis ("positive" result), the corresponding post-test probability for their presence (if pre-test probability was 50%) was 78%, and 88% respectively, while, if values were below these thresholds ("negative" result), the post-test probability was 21% and 16%, respectively. No optimal stiffness cut-offs for individual fibrosis stages were validated in independent cohorts and cut-offs had a wide range and overlap within and between stages. CONCLUSIONS: Elastography theoretically has good sensitivity and specificity for cirrhosis (and less for lesser degrees of fibrosis); however, it should be cautiously applied to everyday clinical practice because there is no validation of the stiffness cut-offs for the various stages. Such validation is required before elastography is considered sufficiently accurate for non-invasive staging of fibrosis.

Systematic review and meta-analysis of intraoperative versus preoperative endoscopic sphincterotomy in patients with gallbladder and suspected common bile duct stones.

BACKGROUND: Most patients with gallbladder and common bile duct stones are treated by preoperative endoscopic sphincterotomy (POES) followed by laparoscopic cholecystectomy. Recently, intraoperative endoscopic sphincterotomy (IOES) during laparoscopic cholecystectomy has been suggested as an alternative treatment. METHODS: Data from randomized clinical trials related to safety and effectiveness of IOES versus POES were extracted by two independent reviewers. Risk ratios (RRs) or mean differences were calculated with 95 per cent confidence intervals based on intention-to-treat analysis whenever possible. RESULTS: Four trials with 532 patients comparing IOES with POES were included. There were no deaths. There was no significant difference in rates of ampullary cannulation (RR 1·01, 0·97 to 1·04; P = 0·70) or stone clearance by ES (RR 0·99, 0·96 to 1·02; P = 0·58) between the groups. The proportion of patients with at least one post-ES complication, including pancreatitis, bleeding, perforation, cholangitis, cholecystitis or gastric ulcer, was significantly lower in the IOES group (RR 0·37, 0·18 to 0·78; P = 0·009). There was no significant difference in morbidity after laparoscopic cholecystectomy or requirement for open operation between the groups. Mean hospital stay was 3 days shorter in the IOES group: mean difference - 2·83 (-3·66 to - 2·00) days (P < 0·001). CONCLUSION: In patients with gallbladder and common bile duct stones, IOES is as effective and safe as POES and results in a significantly shorter hospital stay.

Influence of zinc and zinc chelator on HT-29 colorectal cell line.

Trace elements are involved in many key pathways involving cell cycle control. The influence of zinc and zinc chelator (TPEN) on transcription levels of the main zinc transporters (ZnT1 and ZIP1) in the HT-29 colorectal cell line has not been reported. Proliferation of HT-29 cells was measured using the methylene blue assay after exposure to zinc (two concentrations), TPEN (two concentrations), or a combination of zinc and TPEN (simultaneously and sequentially) for 4 h, 8 h, and 24 h. The transcription levels of ZnT1, ZIP1, vascular endothelial growth factor (VEGF), and caspase-3 were determined using reverse transcriptase real-time polymerase chain reaction (RT-PCR) after exposure of cells to zinc and TPEN. The zinc content in the substrate (medium used for culture) was determined using atomic absorption spectrometry. TPEN decreased cellular proliferation causing complete cell death by 8 h. Zinc had a protective effect against short periods of exposure to TPEN. There was no correlation between the transcripts of main zinc transporters and the zinc content in the substrate. The zinc content in the substrate remained constant after varying periods of cell culture. TPEN decreased the transcript levels of caspase-3 and VEGF, which are surrogate markers for apoptosis and angiogenesis. Zinc chelation of HT-29 cells causes cell death. Zinc appears to be protective for short periods of exposure to TPEN but has no protective effect on prolonged exposure. HT-29 cells are not able to counteract the effect of intracellular chelation of zinc by altering zinc transport. Further research into the mechanisms of these findings is necessary and may lead to novel therapeutic options.

Performance of image guided navigation in laparoscopic liver surgery - A systematic review.

BACKGROUND: Compared to open surgery, minimally invasive liver resection has improved short term outcomes. It is however technically more challenging. Navigated image guidance systems (IGS) are being developed to overcome these challenges. The aim of this systematic review is to provide an overview of their current capabilities and limitations. METHODS: Medline, Embase and Cochrane databases were searched using free text terms and corresponding controlled vocabulary. Titles and abstracts of retrieved articles were screened for inclusion criteria. Due to the heterogeneity of the retrieved data it was not possible to conduct a meta-analysis. Therefore results are presented in tabulated and narrative format. RESULTS: Out of 2015 articles, 17 pre-clinical and 33 clinical papers met inclusion criteria. Data from 24 articles that reported on accuracy indicates that in recent years navigation accuracy has been in the range of 8-15 mm. Due to discrepancies in evaluation methods it is difficult to compare accuracy metrics between different systems. Surgeon feedback suggests that current state of the art IGS may be useful as a supplementary navigation tool, especially in small liver lesions that are difficult to locate. They are however not able to reliably localise all relevant anatomical structures. Only one article investigated IGS impact on clinical outcomes. CONCLUSIONS: Further improvements in navigation accuracy are needed to enable reliable visualisation of tumour margins with the precision required for oncological resections. To enhance comparability between different IGS it is crucial to find a consensus on the assessment of navigation accuracy as a minimum reporting standard.

Cost-utility and value-of-information analysis of early versus delayed laparoscopic cholecystectomy for acute cholecystitis.

BACKGROUND: : A recent systematic review found early laparoscopic cholecystectomy (ELC) to be safe and to shorten total hospital stay compared with delayed laparoscopic cholecystectomy (DLC) for acute cholecystitis. The cost-effectiveness of ELC versus DLC for acute cholecystitis is unknown. METHODS: : A decision tree model estimating and comparing costs to the UK National Health Service (NHS) and quality-adjusted life years (QALYs) gained following a policy of either ELC or DLC was developed with a time horizon of 1 year. Uncertainty was investigated with probabilistic sensitivity analysis, and value-of-information analysis estimated the likely return from further investment in research in this area. RESULTS: : ELC is less costly (approximately - pound820 per patient) and results in better quality of life (+0.05 QALYs per patient) than DLC. Given a willingness-to-pay threshold of pound20 000 per QALY gained, there is a 70.9 per cent probability that ELC is cost effective compared with DLC. Full implementation of ELC could save the NHS pound8.5 million per annum. CONCLUSION: : The results of this decision analytic modelling study suggest that on average ELC is less expensive and results in better quality of life than DLC. Future research should focus on quality-of-life measures alone.

Meta-analysis of randomized controlled trials on the safety and effectiveness of early versus delayed laparoscopic cholecystectomy for acute cholecystitis.

BACKGROUND: : In many countries laparoscopic cholecystectomy for acute cholecystitis is mainly performed after the acute episode has settled because of the anticipated increased risk of morbidity and higher conversion rate from laparoscopic to open cholecystectomy. METHODS: : A systematic review was performed with meta-analysis of randomized clinical trials of early laparoscopic cholecystectomy (ELC; performed within 1 week of onset of symptoms) versus delayed laparoscopic cholecystectomy (performed at least 6 weeks after symptoms settled) for acute cholecystitis. Trials were identified from The Cochrane Library trials register, Medline, Embase, Science Citation Index Expanded and reference lists. Risk ratio (RR) or mean difference was calculated with 95 per cent confidence intervals (c.i.) based on intention-to-treat analysis. RESULTS: : Five trials with 451 patients were included. There was no significant difference between the two groups in terms of bile duct injury (RR 0.64 (95 per cent c.i. 0.15 to 2.65)) or conversion to open cholecystectomy (RR 0.88 (95 per cent c.i. 0.62 to 1.25)). The total hospital stay was shorter by 4 days for ELC (mean difference -4.12 (95 per cent c.i. -5.22 to -3.03) days). CONCLUSION: : ELC during acute cholecystitis appears safe and shortens the total hospital stay.

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.

Top research priorities in healthcare-associated infection in the UK.

BACKGROUND: There is a mismatch between research questions which are considered to be important by patients, carers and healthcare professionals and the research performed in many fields of medicine. No relevant studies which have assessed research priorities in healthcare-associated infection (HCAI) that have involved patients' and carers' opinions were identified in the literature. AIM: The Healthcare-Associated Infections Priority Setting Partnership was established to identify the top research priorities in the prevention, diagnosis and treatment of HCAI in the UK, considering the opinions of all these groups. METHODS: The methods broadly followed the principles of the James Lind Alliance (JLA) priority setting activity. FINDINGS: In total, 259 unique valid research questions were identified from 221 valid responses to a consultation of patients, carers and healthcare professionals after seeking their opinions for research priorities. The steering committee of the priority setting partnership rationalized these to 50 unique questions. A literature review established that for these questions there were no recent high-quality systematic reviews, high-quality systematic reviews which concluded that further studies were necessary, or the steering committee considered that further research was required despite the conclusions of recent systematic reviews. An interim survey ranked the 50 questions, and the 10 main research priorities were identified from the top 32 questions by consensus at a final priority setting workshop of patients, carers and healthcare professionals using group discussions. CONCLUSIONS: A priority setting process using JLA methods and principles involving patients, carers and healthcare professionals was used to identify the top 10 priority areas for research related to HCAI. Basic, translational, clinical and public health research would be required to address these uncertainties.

Meta-analysis of randomized controlled trials on the safety and effectiveness of day-case laparoscopic cholecystectomy.

BACKGROUND: Although day-case laparoscopic cholecystectomy can save bed costs, its safety has to be established. The aim of this meta-analysis is to assess the advantages and disadvantages of day-case surgery compared with overnight stay in patients undergoing elective laparoscopic cholecystectomy. METHODS: Randomized clinical trials addressing the above issue were identified from The Cochrane Library trials register, Medline, Embase, Science Citation Index Expanded and reference lists. Data were extracted from these trials by two independent reviewers. For each outcome the relative risk, weighted mean difference or standardized mean difference was calculated with 95 per cent confidence intervals based on available case analysis. RESULTS: Five trials with 215 patients randomized to the day-case group and 214 to the overnight-stay group were included in the review. Four of the five trials were of low risk of bias. The trials recruited 49.1 per cent of patients presenting for cholecystectomy. There was no significant difference between day case and overnight stay with respect to morbidity, prolongation of hospital stay, readmission rates, pain, quality of life, patient satisfaction, and return to normal activity and work. In the day-case group 80.5 per cent of patients were discharged on the day of surgery. CONCLUSION: Day-case laparoscopic cholecystectomy is a safe and effective treatment for symptomatic gallstones.

Systematic review of randomized controlled trials on the effectiveness of virtual reality training for laparoscopic surgery.

BACKGROUND: Surgical training has traditionally been one of apprenticeship. The aim of this review was to determine whether virtual reality (VR) training can supplement and/or replace conventional laparoscopic training in surgical trainees with limited or no laparoscopic experience. METHODS: Randomized clinical trials addressing this issue were identified from The Cochrane Library trials register, Medline, Embase, Science Citation Index Expanded, grey literature and reference lists. Standardized mean difference was calculated with 95 per cent confidence intervals based on available case analysis. RESULTS: Twenty-three trials (mostly with a high risk of bias) involving 622 participants were included in this review. In trainees without surgical experience, VR training decreased the time taken to complete a task, increased accuracy and decreased errors compared with no training. In the same participants, VR training was more accurate than video trainer (VT) training. In participants with limited laparoscopic experience, VR training resulted in a greater reduction in operating time, error and unnecessary movements than standard laparoscopic training. In these participants, the composite performance score was better in the VR group than the VT group. CONCLUSION: VR training can supplement standard laparoscopic surgical training. It is at least as effective as video training in supplementing standard laparoscopic training.

Abdominal lift for laparoscopic cholecystectomy.

BACKGROUND: Laparoscopic cholecystectomy is the main method of treatment of symptomatic gallstones. Several cardiopulmonary changes (decreased cardiac output, pulmonary compliance, and increased peak airway pressure) occur during pneumoperitoneum. These changes may not be tolerated in individuals with poor cardiopulmonary reserve. OBJECTIVES: To assess the benefits and harms of abdominal wall lift compared to 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 in The Cochrane Library, MEDLINE, EMBASE, and Science Citation IndexExpanded until January 2007. SELECTION CRITERIA: We included all randomised clinical trials comparing abdominal wall lift (with or without pneumoperitoneum) and pneumoperitoneum. DATA COLLECTION AND ANALYSIS: We calculated the relative risk (RR), weighted mean difference (WMD) or standardised mean difference (SMD) with 95% confidence intervals (CI) based on intention-to-treat analysis with both the fixed-effect and the random-effects model using RevMan Analysis. MAIN RESULTS: Abdominal wall lift with pneumoperitoneum versus pneumoperitoneum. A total of 156 participants (all with low anaesthetic risk) who underwent elective laparoscopic cholecystectomy were randomised in six trials to abdominal wall lift with pneumoperitoneum (n = 65) versus pneumoperitoneum only (n = 66). One trial which included 25 patients did not state the number of patients in each group. All six trials were of high risk of bias. The cardiopulmonary changes were less in abdominal wall lift than pneumoperitoneum. There was no difference in the morbidity and pain between the groups. Abdominal wall lift versus pneumoperitoneum. A total of 550 participants (the majority with low anaesthetic risk) who underwent elective laparoscopic cholecystectomy were randomised in fourteen trials to abdominal wall lift without pneumoperitoneum (n = 268) versus pneumoperitoneum (n = 282). Two of these fourteen trials were of low risk of bias. The cardiopulmonary changes were less in abdominal wall lift than with pneumoperitoneum. There was no difference in the morbidity and pain between the groups. The operating time was prolonged in abdominal wall lift compared with pneumoperitoneum (WMD 7.74, 95% CI 1.37 to 14.12). AUTHORS' CONCLUSIONS: (1) Abdominal wall lift seems safe and decreases the cardiopulmonary changes associated with laparoscopic cholecystectomy.(2) Abdominal wall lift does not seem to offer advantage over pneumoperitoneum in any of the patient-oriented outcomes for laparoscopic cholecystectomy in patients with low anaesthetic risk and may increase costs by increasing the operating time. Hence it cannot be recommended routinely. More research on the topic is needed.

Ischaemic preconditioning for liver transplantation.

BACKGROUND: Ischaemic preconditioning is a mechanism for reducing organ ischaemia reperfusion injury by a brief period of organ ischaemia. OBJECTIVES: To assess the advantages and disadvantages of ischaemic preconditioning during donor hepatectomy for liver transplant recipients. 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 only randomised clinical trials comparing ischaemic preconditioning versus no ischaemic preconditioning during donor liver retrievals performed in humans in this review (irrespective of language or publication status). DATA COLLECTION AND ANALYSIS: We collected the data on the characteristics of the trial, methodological quality of the trials, mortality, initial poor function, primary graft non-function, re-transplantation, liver function tests, markers of neutrophil activation, apoptosis, and intensive therapy unit stay. We analysed the data with both the fixed-effect and the random-effects models. 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% CI. MAIN RESULTS: In three trials, 162 cadaveric liver donor retrievals were randomised; 78 to ischaemic preconditioning and 84 to no ischaemic preconditioning. In one trial, 15 living donor liver retrievals were randomised; 10 to ischaemic preconditioning and 5 to no ischaemic preconditioning. Three of the four trials were of low-risk bias. There was no statistically significant difference in mortality, initial poor function, primary graft non-function, or re-transplant. There was no statistically significant difference in the transaminase activity, bilirubin level, prothrombin activity, median myeloperoxidase activity, median cluster of differentiation eight (CD8) expression, median inducible nitrogen oxide synthetase, or apoptosis. There was also no significant difference in the median intensive therapy unit stay of the recipients. AUTHORS' CONCLUSIONS: There is currently no evidence to support or refute the use of ischaemic preconditioning in donor liver retrievals. Further studies are necessary to identify the optimal ischaemic preconditioning stimulus. Further randomised clinical trials are necessary to evaluate the role of ischaemic preconditioning in donor liver retrievals involving a period of warm reperfusion, following ischaemic preconditioning during donor liver retrieval.