An adaptable research platform for ex vivo normothermic machine perfusion of the liver

PURPOSE

This paper presents an assessment of a low-cost organ perfusion machine designed for use in research settings. The machine is modular and versatile in nature, built on a robotic operating system (ROS2) pipeline allowing for the addition of specific sensors for different research applications. Here we present the system and the development stages to achieve viability of the perfused organ.

METHODS

The machine's perfusion efficacy was assessed by monitoring the distribution of perfusate in livers using methylene blue dye. Functionality was evaluated by measuring bile production after 90 min of normothermic perfusion, while viability was examined using aspartate transaminase assays to monitor cell damage throughout the perfusion. Additionally, the output of the pressure, flow, temperature, and oxygen sensors was monitored and recorded to track the health of the organ during perfusion and assess the system's capability of maintaining the quality of data over time.

RESULTS

The results show the system is capable of successfully perfusing porcine livers for up to three hours. Functionality and viability assessments show no deterioration of liver cells once normothermic perfusion had occurred and bile production was within normal limits of approximately 26 ml in 90 min showing viability.

CONCLUSION

The developed low-cost perfusion system presented here has been shown to keep porcine livers viable and functional ex vivo. Additionally, the system is capable of easily incorporating several sensors into its framework and simultaneously monitor and record them during perfusion. The work promotes further exploration of the system in different research domains.

Evaluation of A Novel Organ Perfusion Research Platform

This paper presents a novel, low cost, organ perfusion machine designed for use in research. The modular and versatile nature of the system allows for additional sensing equipment to be added or adapted for specific use. Here we introduce the system and present its preliminary evaluation by assessing its ability to maintain a predetermined input pressure. A proportional-integral-derivative (PID) controller was implemented and tested on a porcine liver to maintain input pressure to the hepatic artery and compared to bench tests. The results confirmed the effectiveness of the controller for maintaining input through the hepatic artery (HA) in a timely manner. Clinical Relevance-Machine Perfusion (MP) is proving to be an invaluable adjunct in clinical practice. With its ongoing success in the transplant arena, we propose MP for use in research. A cost-effective, versatile system that can be modified for specific research use to test new pharmacological therapies, imaging techniques or develop simulation training would be beneficial.

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.

5-Aminolevulinic acid for fluorescence-guided surgery in pancreatic cancer: Cellular transport and fluorescence quantification studies

5-Aminolevulinic acid (ALA) is a potential contrast agent for fluorescence-guided surgery in pancreatic ductal adenocarcinoma (PDAC). However, factors influencing ALA uptake in PDAC have not been adequately assessed. We investigated ALA-induced porphyrin fluorescence in PDAC cell lines CFPAC-1 and PANC-1 and pancreatic ductal cell line H6c7 following incubation with 0.25-1.0 mM ALA for 4-48 h. Fluorescence was assessed qualitatively by microscopy and quantitatively by plate reader and flow cytometry. Haem biosynthesis enzymes and transporters were measured by quantitative polymerase chain reaction (qPCR). CFPAC-1 cells exhibited intense fluorescence under microscopy at low concentrations whereas PANC-1 cells and pancreatic ductal cell line H6c7 showed much lower fluorescence. Quantitative fluorescence studies demonstrated fluorescence saturation in the two PDAC cell lines at 0.5 mM ALA, whereas H6c7 cells showed increasing fluorescence with increasing ALA. Based on the PDAC:H6c7 fluorescence ratio studies, lower ALA concentrations provide better contrast between PDAC and benign pancreatic cells. Studies with qPCR showed upregulation of ALA influx transporter PEPT1 in CFPAC-1, whereas PANC-1 upregulated the efflux transporter ABCG2. We conclude that PEPT1 and ABCG2 expression may be key contributory factors for variability in ALA-induced fluorescence in PDAC.

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.

Evolution of dynamic, biochemical, and morphological parameters in hypothermic machine perfusion of human livers: A proof-of-concept study

INTRODUCTION

Hypothermic machine perfusion (HMP) is increasingly investigated as a means to assess liver quality, but data on viability markers is inconsistent and the effects of different perfusion routes and oxygenation on perfusion biomarkers are unclear.

METHODS

This is a single-centre, randomised, multi-arm, parallel study using discarded human livers for evaluation of HMP using arterial, oxygen-supplemented venous and non-oxygen-supplemented venous perfusion. The study included 2 stages: in the first stage, 25 livers were randomised into static cold storage (n = 7), hepatic artery HMP (n = 10), and non-oxygen-supplemented portal vein HMP (n = 8). In the second stage, 20 livers were randomised into oxygen-supplemented and non-oxygen-supplemented portal vein HMP (n = 11 and 9, respectively). Changes in dynamic, biochemical, and morphologic parameters during 4-hour preservation were compared between perfusion groups, and between potentially transplantable and non-transplantable livers.

RESULTS

During arterial perfusion, resistance was higher and flow was lower than venous perfusion (p = 0.001 and 0.01, respectively); this was associated with higher perfusate markers during arterial perfusion (p>0.05). Supplementary oxygen did not cause a significant alteration in the studied parameters. Morphology was similar between static and dynamic preservation groups. Perfusate markers were 2 fold higher in non-transplantable livers (p>0.05).

CONCLUSIONS

Arterial only perfusion might not be adequate for graft perfusion. Hepatocellular injury markers are accessible and easy to perform and could offer insight into graft quality, but large randomised trials are needed to identify reliable quality assessment biomarkers.

Alterations in coagulation following major liver resection

The international normalised ratio is frequently raised in patients who have undergone major liver resection, and is assumed to represent a potential bleeding risk. However, these patients have an increased risk of venous thromboembolic events, despite conventional coagulation tests indicating hypocoagulability. This prospective, observational study of patients undergoing major hepatic resection analysed the serial changes in coagulation in the early postoperative period. Thrombin generation parameters and viscoelastic tests of coagulation (thromboelastometry) remained within normal ranges throughout the study period. Levels of the procoagulant factors II, V, VII and X initially fell, but V and X returned to or exceeded normal range by postoperative day five. Levels of factor VIII and Von Willebrand factor were significantly elevated from postoperative day one (p < 0.01). Levels of the anticoagulants, protein C and antithrombin remained significantly depressed on postoperative day five (p = 0.01). Overall, the imbalance between pro- and anticoagulant factors suggested a prothrombotic environment in the early postoperative period.

A diaphragmatic retroperitoneal cyst

Diaphragmatic lesions are usually congenital bronchogenic cysts. A patient with a known diaphragmatic cyst presented with new onset right upper quadrant pain. Repeat imaging showed enlargement of the cyst, the CA19-9 cancer marker was raised at 312 iu/ml (normal: <27 iu/ml) and positron emission tomography combined with computed tomography showed focally increased uptake in the cystic wall. In view of symptoms and risk of neoplasia, the lesion was excised. Histology showed a benign epidermoid cyst. Features falsely suggesting neoplasia have been reported previously with benign splenic cysts but not with a benign diaphragmatic epidermoid cyst.

Outcome after surgical resection for duodenal adenocarcinoma in the UK

BACKGROUND

Factors influencing long-term outcome after surgical resection for duodenal adenocarcinoma are unclear.

METHODS

A prospectively created database was reviewed for patients undergoing surgery for duodenal adenocarcinoma in six UK hepatopancreaticobiliary centres from 2000 to 2013. Factors influencing overall survival and disease-free survival (DFS) were identified by regression analysis.

RESULTS

Resection with curative intent was performed in 150 (84·3 per cent) of 178 patients. The postoperative morbidity rate for these patients was 40·0 per cent and the in-hospital mortality rate was 3·3 per cent. Patients who underwent resection had a better median survival than those who had a palliative surgical procedure (84 versus 8 months; P < 0·001). The 1-, 3- and 5-year overall survival rates for patients who underwent resection were 83·9, 66·7 and 51·2 per cent respectively. Median DFS was 53 months, and 1- and 3-year DFS rates were 80·8 and 56·5 per cent respectively. Multivariable analysis revealed that node status (hazard ratio 1·73, 95 per cent c.i. 1·07 to 2·79; P = 0·006) and lymphovascular invasion (hazard ratio 3·49, 1·83 to 6·64; P = 0·003) were associated with overall survival.

CONCLUSION

Resection of duodenal adenocarcinoma in specialist centres is associated with good long-term survival. Lymphovascular invasion and nodal metastases are independent prognostic indicators.

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.

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.

31-Phosphorus magnetic resonance spectroscopy for dynamic assessment of adenosine triphosphate levels in pancreas preserved by the two-layer method

Cold preservation injury influences islet graft function. Reliable tools for real-time assessment of pancreas viability before islet isolation are lacking. Phosphorus magnetic resonance spectroscopy ((31)P-MRS) was used immediately after organ harvest to study rat pancreases at 4 °C to 6 °C in five randomized preservation groups: Marshall's solution, static two-layer method (TLM), continuous TLM with oxygen perfused at 0.5 L/min, and static TLM or continuous TLM both the latter following 30 minutes of warm ischemia (WI). (31)P spectra were analyzed for phosphomonoesters, inorganic phosphate (Pi) and α-, β-and γ-nucleotide triphosphate. Intergroup rates of change of [γ-adenosine triphosphate (ATP)]/[Pi] and [β-ATP]/[Pi] throughout preservation period were significantly different. For continuous TLM there was an increase relative to baseline (0.043 (SD0.033) h(-1) and 0.029 (0.029) h(-1), respectively) but a decrease for both static TLM (-0.023 (0.016) h(-1) and 0.015 (0.026), P < .001 and < .05, respectively) and Marshall's (-0.049 (0.025) h(-1) and -0.036 (0.019) h(-1), respectively, both P < .001) with respect to continuous TLM. Rate of decrease was similar for the Marshall's and static TLM groups. [γ-ATP]/[Pi] and [β-ATP]/[Pi] increased with WI continuous TLM (0.008 [0.009] h(-1) and 0.007 [0.008] hr(-1), respectively) but decreased for WI static TLM (-0.018 (0.008) h(-1) and -0.014 (0.004) hr(-1), respectively, P < .001). (31)P-MRS is an effective tool for noninvasive assessment of pancreas bioenergetics. Continuous TLM preserves cellular bioenergetics and is superior to current non-perfluorocar bone based solutions for pancreas preservation.

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.

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.

R0 but not R1/R2 resection is associated with better survival than palliative photodynamic therapy in biliary tract cancer

BACKGROUND

There is a need for better management strategies to improve the survival and quality of life in patients with biliary tract cancer (BTC).

AIM

To assess prognostic factors for survival in a large, non-selective cohort of patients with BTC.

METHOD

We compared outcomes in 321 patients with a final diagnosis of BTC (cholangiocarcinoma n = 237, gallbladder cancer n = 84) seen in a tertiary referral cancer centre between 1998 and 2007. Survival according to disease stage and treatment category was compared using log-rank testing. Cox's regression analysis was used to determine independent prognostic factors.

RESULTS

Eighty-nine (28%) patients underwent a surgical intervention with curative intent, of whom 38% had R0 resections. Among the 321 patients, 34% were given chemo- and/or radiotherapy, 14% were palliated with photodynamic therapy (PDT) and 37% with biliary drainage procedures alone. The overall median survival was 9 months (3-year survival, 14%). R0-resective surgery conferred the most favourable outcome (3-year survival, 57%). Although patients palliated with PDT had more advanced clinical T-stages, their survival was similar to those treated with attempted curative surgery but who had positive resection margins. On multivariable analysis, treatment modality, serum carbohydrate-associated antigen 19-9, distant metastases and vascular involvement were independent prognostic indicators of survival.

CONCLUSION

In this large UK series of BTC, palliative PDT resulted in survival similar to those with curatively intended R1/R2 resections. Surgery conferred a survival advantage only in patients with R0 resection margins, emphasising the need for accurate pre-operative staging.

Biochemical indicators of in-hospital complications following pancreatic surgery

Early recognition of complications following pancreatic surgery could reduce morbidity and mortality. White cell counts (WCCs), platelets (PLTs), C-reactive protein (CRP) and albumin (ALB) are commonly used as guides in clinical decision making. However, the evidence to support their role as early indicators of complications is unclear. A retrospective cohort analysis of consecutive pancreatic surgical procedures between 2004 and 2008 was performed. Operative procedures, inflammatory markers--WCCs, PLTs, CRP, and ALB--preoperatively and on postoperative days (PODs) 1, 3, 5, 7, 9, 12, and 15, and clinical outcomes were recorded. WCC > 11 x 10(9)/L on POD5 was significantly associated with complications [odds ratio (OR), 2.60; P = 0.0067]. ALB < 28 g/L on POD7 was significantly associated with a postoperative complication (OR, 2.94; P = 0.0031). WCC > 12.2 x 10(9)/L and ALB < or = 28 g/L on POD7 were more likely to be associated with a complication (OR, 4.86; P = 0.0002). Postoperative WCC and ALB levels may be useful as aids to the early diagnosis of complications following pancreatic surgery.

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

The original article to which this Erratum refers was published in British Journal of Surgery 2010; 97: 141–150.

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.

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.

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.

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.

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.

Tumour size and differentiation in predicting recurrence of hepatocellular carcinoma after liver transplantation: external validation of a new prognostic score

BACKGROUND

A new prognostic score including tumour differentiation--establishing two groups of patients: group A with >3 points and group B with >4 points--improved the accuracy of the Milan criteria in predicting recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT) in a large multicentre study (Decaens 2007).

AIM

The aim of this study was to validate the new score in our HCC cohort.

METHODS

The study involved 100 consecutive patients with mean age 55 years (range 31-68 years) (M/F: 88/22) transplanted for known HCC: 60 unifocal and 40 multifocal (2-3 nodules in 32 and >or=4 nodules in 8) at pre-LT imaging. Survival differences were analysed by log-rank test. Patient/tumour variables before LT and tumour differentiation at explant were assessed by univariate/multivariate analysis.

RESULTS

Median follow-up was 29 months (range 1-145 months). HCC recurrence was recorded in 18 patients. Five-year recurrence-free survival rate was 67 +/- 7%. Patient survival at 3 months was 84 +/- 4% and at 5 years was 45 +/- 6%. Both recurrence-free survival and patient survival were not significantly different between groups A and B. Diameter of largest nodule was the sole pre-LT variable independently associated with recurrence [odd ratio (OR) 1.07; 95% confidence interval (CI) 1.01-1.12; P = 0.012]. Recurrence-free survival was significantly better in patients with diameter <30 mm compared with those with larger nodules (P = 0.0229). Number of nodules and tumour differentiation did not influence recurrence. There were three HCC recurrences with largest nodule size <30 mm, seven recurrences between 30-40 mm, and eight recurrences >40 mm.

CONCLUSION

Tumour differentiation did not add significantly to prediction of HCC recurrence in our cohort. Conversely, diameter of the largest nodule remained a significant risk for recurrence.

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.

Outcome of R1 resection in patients undergoing pancreatico-duodenectomy for pancreatic cancer

BACKGROUND

Pancreatico-duodenectomy (PD) is the only potentially curative treatment for pancreatic cancer, but most surgeons are reluctant to perform a palliative resection. The aim was to define the outcome for microscopically incomplete PD (R1).

METHODS

Ninety-nine consecutive patients underwent laparotomy to perform PD. Sixty-seven patients were resected and 32 underwent palliative bypass (PSB) because of locally advanced disease.

RESULTS

Of the 67 PD, 27 were classified as R0 and 40 as R1. Median survival for R0, R1 and PSB were 24, 18 and 9 months, respectively. Survival in the PSB group was 34% at 1 year and 0% at 2 years. 1-, 2- and 5-year survival in the R0 and R1 groups was 79% and 70%, 48.3% and 39.1%, 21.5% and 9.9%, respectively. Compared to PSB, both other groups were less likely to die over follow-up (p=0.002). Survival was not significantly different between the R0 and R1 groups (p=0.21). Perioperative morbidity and mortality were similar in the PD and PSB groups (29.9% and 3.0% vs 31.3 and 3.1%, respectively, p=1.00).

CONCLUSIONS

Better survival in the resection group and similar perioperative risk would support the decision to perform PD even when there is the possibility of incomplete microscopic clearance.

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.

Day-case versus overnight stay in laparoscopic cholecystectomy

BACKGROUND

Although day-case elective laparoscopic cholecystectomy can save bed costs, its safety remains to be established.

OBJECTIVES

To assess the safety and benefits of day-case surgery compared to overnight stay in patients undergoing elective 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 February 2007 for identifying randomised trials using search strategies.

SELECTION CRITERIA

Only randomised clinical trials, irrespective of language, blinding, or publication status, comparing day-case and overnight stay in elective laparoscopic cholecystectomy were considered for the review.

DATA COLLECTION AND ANALYSIS

We collected the data on the characteristics of the trial, methodological quality of the trials, morbidity, prolonged hospitalisation, re-admissions, pain and quality of life from each trial. We analysed the data with both the fixed-effect and the random-effects models using RevMan Analysis. For each outcome we calculated the relative risk, weighted mean difference, or standardised mean difference with 95% confidence intervals (CI) based on available case-analysis.

MAIN RESULTS

Five trials with 429 patients randomised to the day-case group (215) and overnight stay group (214) were included in the review. Four of the five trials were of low risk of bias regarding randomisation and follow up, but all lacked blinding. The trials recruited 49% of patients undergoing cholecystectomy. The selection criteria varied, but most included only patients without other diseases. The patients were living in easy reach of the hospital and with a responsible adult to take care of them. On the day of surgery, 81% of day-case patients were discharged. The drop-out rate after randomisation varied from 6.5% to 12.7%. There was no significant difference between day-case and overnight stay group as regards to morbidity, prolongation of hospital stay, re-admission rates, pain, quality of life, patient satisfaction and return to normal activity and work.

AUTHORS' CONCLUSIONS

Day-case elective laparoscopic cholecystectomy seems to be a safe and effective intervention in selected patients (with no or minimal systemic disease and within easy reach of the hospital) with symptomatic gallstones. Because of the decreased hospital stay, it is likely to save costs.

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.

Is preoperative histological diagnosis necessary for cholangiocarcinoma?

Surgery is currently the only curative treatment for patients with cholangiocarcinoma (CCA). Whether histological diagnosis of CCA is necessary before surgery is controversial. Fifteen percent of patients with suspected biliary malignancy who undergo surgery are found to have benign disease. Surgery is a major procedure with significant morbidity and mortality and alternative treatment is available for those known to have benign stenoses. The aim of this review was to determine whether any of the current diagnostic tests have sufficient sensitivity and specificity to identify patients with benign and malignant bile duct stenoses. A literature search was performed until July 2007 to obtain information from studies published in the previous 10 years. Only studies reporting an appropriate reference test (confirmation of malignancy by biopsy, confirmation of benign nature by histology following surgical excision, or at least 6 months of follow-up for all patients) were included for review. The diagnostic odds ratio was used to measure diagnostic performance. Forty-one references of 34 studies were included in this review. None of the studies used differential verification. Six studies used blinding of assessor. None of the diagnostic tests had sufficient diagnostic accuracy to reliably separate patients with benign from malignant biliary strictures. Differentiating benign from malignant bile strictures is an important aim. There is no trial evidence demonstrating benefit in obtaining a preoperative histological diagnosis of CCA. New methods are required for stricture assessment.

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.

Routine abdominal drainage for uncomplicated laparoscopic cholecystectomy

BACKGROUND

Laparoscopic cholecystectomy is the main method of treatment of symptomatic gallstones. Drains are used after laparoscopic cholecystectomy to prevent abdominal collections. However, drain use may increase infective complications and delay discharge.

OBJECTIVES

The aim is to assess the benefits and harms of routine abdominal drainage in uncomplicated 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 March 2007.

SELECTION CRITERIA

We included all randomised clinical trials comparing drainage with no drainage after uncomplicated laparoscopic cholecystectomy. Randomised clinical trials comparing one type of drain with another were also reviewed.

DATA COLLECTION AND ANALYSIS

We collected the data on the characteristics, methodological quality, mortality, abdominal collections, pain, nausea, vomiting, and hospital stay from each trial. We analysed the data with both the fixed-effect and the random-effects models using RevMan Analysis. For each outcome we calculated the odds ratio (OR) with 95% confidence intervals (CI) based on intention-to-treat analysis.

MAIN RESULTS

We analysed six trials involving 741 patients randomised to drain (361) versus no drain (380). The only patient with abdominal collections requiring intervention belonged to the drain group. Wound infection was significantly higher in those with a drain (OR 5.86, 95% CI 1.05 to 32.70). Drainage was associated with nausea, but this was not statistically significant. Hospital stay was longer in the drain group and the number of patients discharged at the day of operation was significantly reduced in the no drain group (OR 2.45, 95% CI 0.00 to 0.57, 1 trial). We also reviewed one trial with 41 patients randomised to suction drain (22) versus closed passive drain (19). This trial suggests that suction drains carried less pain than passive drains.

AUTHORS' CONCLUSIONS

Drain use after elective laparoscopic cholecystectomy increases wound infection rates and delays hospital discharge. We could not find evidence to support the use of drain after laparoscopic cholecystectomy.

Routine abdominal drainage for uncomplicated laparoscopic cholecystectomy

BACKGROUND

Laparoscopic cholecystectomy is the main method of treatment of symptomatic gallstones. Drains are used after laparoscopic cholecystectomy to prevent abdominal collections. However, drain use may increase infective complications and delay discharge.

OBJECTIVES

The aim is to assess the benefits and harms of routine abdominal drainage in uncomplicated 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 March 2007.

SELECTION CRITERIA

We included all randomised clinical trials comparing drainage with no drainage after laparoscopic cholecystectomy. Randomised clinical trials comparing one type of drain with another were also reviewed.

DATA COLLECTION AND ANALYSIS

We collected the data on the characteristics, methodological quality, mortality, abdominal collections, pain, nausea, vomiting, and hospital stay from each trial. We analysed the data with both the fixed-effect and the random-effects models using RevMan Analysis. For each outcome we calculated the odds ratio (OR) with 95% confidence intervals (CI) based on intention-to-treat analysis.

MAIN RESULTS

We analysed five trials involving 591 patients randomised to drain (281) versus no drain (310). We also reviewed one trial with 41 patients randomised to suction drain (22) versus closed passive drain (19). The only trial that reported on abdominal collections requiring intervention reported no abdominal collections requiring intervention in either group. Wound infection tended to be higher in those with a drain (OR 15.38, 95% CI 0.86 to 275.74). Drainage was associated with lower shoulder, abdominal pain, and nausea, but this was not statistically significant. Hospital stay was longer in the drain group.

AUTHORS' CONCLUSIONS

Drain use after elective laparoscopic cholecystectomy reduces early post-operative pain, but increases wound infection rates and delays hospital discharge. We could not find evidence to support the use of drain after laparoscopic cholecystectomy.

Routine abdominal drainage for uncomplicated liver resection

BACKGROUND

The main reasons for inserting a drain after elective liver resections are (i) prevention of sub-phrenic or sub-hepatic fluid collection; (ii) identification and monitoring of post-operative bleeding; (iii) identification and drainage of any bile leak; and (iv) prevent the accumulation of ascitic fluid in cirrhotics. However, there are reports that drain use increases the complication rates.

OBJECTIVES

To assess the benefits and harms of routine abdominal drainage in 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 March 2007.

SELECTION CRITERIA

We included all randomised trials comparing abdominal drainage and no drainage in adults undergoing elective liver resection. We also included randomised trials comparing different types of drain in adults undergoing elective liver resection.

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 from each trial. We analysed the data with both the fixed-effect and the random-effects models using the Cochrane Collaboration statistical software RevMan Analysis. For each outcome we calculated the odds ratio (OR) with 95% confidence intervals (CI) (based on intention-to-treat analysis) by combining the trial data sets using fixed-effect model or random-effects model, as appropriate.

MAIN RESULTS

Drain versus no drain: We included five trials with 465 patients randomised: 234 to the drain group and 231 to the no drain group. Three of the five trials were of high methodological quality. There was no statistically significant difference between the two groups for any of the outcomes (mortality, intra-abdominal collections requiring re-operation, infected intra-abdominal collections, wound infection, ascitic leak, and hospital stay, when the random-effects model was adopted. Open drain versus closed drain: One randomised clinical trial of low methodological quality comparing open with closed drainage (186 patients) showed a lower incidence of infected intra-abdominal collections, chest complications, and hospital stay in the closed drain group.

AUTHORS' CONCLUSIONS

There is no evidence to support routine drain use after uncomplicated liver resections.

Preoperative chemotherapy and the outcome of liver resection for colorectal metastases

BACKGROUND

Neoadjuvant systemic chemotherapy is being increasingly used prior to liver resection for colorectal metastases. Oxaliplatin has been implicated in causing structural changes to the liver parenchyma, and such changes may increase the morbidity and mortality of surgery.

PATIENTS AND METHODS

A retrospective study was undertaken of 101 consecutive patients who had undergone liver resection for colorectal metastases in two HPB centers. Preoperative demographic and premorbid data were gathered along with liver function tests and tumor markers. A subjective assessment of the surgical procedure was noted, and in-hospital morbidity and mortality were calculated. The effect of preoperative chemotherapy on short-term and long-term outcome was analyzed, and actuarial 1 and 3 year survival was determined.

RESULTS

Patients who received neoadjuvant chemotherapy had a higher number of metastases (median 2, range 1-8 versus median 1, range 1-5; P = 0.019) and more had synchronous tumors (24 patients versus 8; P < 0.001). Overall morbidity was 37% and hospital mortality was 3.9%. Operative and in-hospital outcome was not influenced by chemotherapy. Long-term survival was worse in patients who had received preoperative chemotherapy (actuarial 3-year survival 62% versus 80%; P = 0.04).

CONCLUSIONS

This study shows no evidence that neoadjuvant chemotherapy, and in particular oxaliplatin, increases the risk associated with liver resection for colorectal metastases. Long-term outcome is reduced in patients receiving preoperative chemotherapy, although they have more advanced disease.

Trace element concentration in metastatic liver disease: a systematic review

BACKGROUND

There are conflicting reports about the levels of trace elements in secondary liver cancers. This review summarises the evidence associating secondary liver tumours with trace elements.

METHODS

MEDLINE, EMBASE and CENTRAL databases were searched for the period up to January 2006 using a formal search strategy. Various inclusion and exclusion criteria were applied to select the articles for inclusion. Data extraction was performed using a custom designed data extraction form.

RESULTS

A total of 6917 references were identified. About 1359 duplicates were excluded using EndNote. About 5529 clearly irrelevant references were excluded through reading titles and abstracts. Of these 24 references were excluded by applying the exclusion criteria. Five studies including 239 patients and measuring iron content (2), copper content (4) and zinc (3) qualified for the review. Both studies on iron, three studies on copper and all the studies on zinc used quantitative methods to determine mineral content. A meta-analysis was performed using the random effects model.

CONCLUSION

Copper and zinc content are lower in secondary liver cancer compared to livers from healthy patients. Iron, copper and zinc content are lower in liver secondaries compared to the normal tissues surrounding the secondaries. Reasons and implications for the trace element alterations should be further investigated.

The Role of Glycine in Hepatic Ischemia-Reperfusion Injury

Glycine is a non-essential amino acid which is cheap, easily available and relatively non-toxic. It is composed of a single carbon attached to an amino and a carboxyl group, with a molecular weight of 75. It is involved in the production of bile, nucleic acids, porphyrins and creatine phosphate. It is part of the normal human diet and is used clinically, as an irrigant solution in urological and gynaecological procedures. Glycine has broad spectrum anti-inflammatory, cytoprotective and immunomodulatory properties whose therapeutic role has largely been un-investigated. Since the demonstration of its cytoprotective effect on hypoxic cultured renal tubule cells, further research has established its mechanism of anti-inflammatory action, which depends on stimulation of glycine sensitive chloride channel receptors on the cell membrane. The mechanism of non-specific cytoprotective effect which is present even in chloride and calcium free media is not clear. However glycine is currently being used experimentally, in human liver transplant recipients and has been shown to be beneficial in animal models of ischemia-reperfusion injury (IRI) in liver and several other organs. This review addresses the properties of glycine, its mechanism of action and its role in modulating IRI with special reference to the liver, with the aim of stimulating translational research into the potential role of glycine as a pharmaceutical agent.

Rejection rates in a randomised trial of tacrolimus monotherapy versus triple therapy in liver transplant recipients with hepatitis C virus cirrhosis

BACKGROUND

Reducing immunosuppression not only reduces complications but also may lessen recurrent hepatitis C virus (HCV) infection after liver transplantation.

PATIENTS/METHODS

HCV-infected cirrhotic patients randomised to tacrolimus monotherapy (MT) or triple therapy (TT) using tacrolimus 0.1 mg/kg/day, azathioprine 1 mg/kg/day, and prednisolone 20 mg/day, tapering over 3 months.

RESULTS

Twenty-seven patients (MT) and 29 (TT)--median follow up 661 days (range, 1-1603). Rejection episodes (protocol/further biopsies) within first 3 months and use of empirical treatment were evaluated. New rejection was diagnosed if repeat biopsy (5-day interval) did not show improvement. Treated rejection episodes: 20 MT (15 biopsy-proven) vs. 24 TT (21 biopsy-proven), with 19 (MT) vs. 24 (TT) methylprednisolone boluses. Overall: 35 episodes (MT) and 46 (TT). Fewer MT patients had histological rejection (70%) than TT patients (86%), with fewer episodes of rejection (18.5% vs. 10%), and more moderate rejection (22% vs. 41%). The MT group had higher early tacrolimus levels. Rates of renal dysfunction, retransplantation, and death were not significantly different.

CONCLUSION

Tacrolimus monotherapy is a viable immunosuppressive strategy in HCV-infected liver transplant recipients.

Remote ischaemic preconditioning of the hind limb reduces experimental liver warm ischaemia-reperfusion injury

BACKGROUND

Direct ischaemic preconditioning of the liver reduces ischaemia-reperfusion injury (IRI). Remote ischaemic preconditioning (RIPC) of a limb has been shown to reduce IRI to the heart. This study determined the effect of brief remote ischaemia to the limb in reducing early liver warm IRI.

METHODS

Twenty-eight male rabbits were allocated to four groups: sham operated, RIPC alone, IRI alone, and RIPC plus IRI. RIPC was induced in the leg with a tourniquet, before liver IRI, by three alternate cycles of 10 min ischaemia followed by 10 min reperfusion. Liver IRI was produced by total inflow occlusion for 25 min. Markers of liver injury and systemic and hepatic haemodynamics were measured for 2 h after reperfusion.

RESULTS

At 2 h, IRI alone was associated with increased serum levels of aminotransferases, and reduced mean arterial blood pressure, hepatic blood flow and peripheral oxygen saturation. There was significant improvement in these variables in animals that had RIPC before liver IRI, and hepatic venous nitrate/nitrite levels were also significantly higher.

CONCLUSION

In this experimental model RIPC appeared to reduce liver IRI.

Intensive follow-up after liver resection for colorectal liver metastases: results of combined serial tumour marker estimations and computed tomography of the chest and abdomen - a prospective study

The aim of the study was to prospectively evaluate an intensive follow-up programme using serial tumour marker estimations and contrast-enhanced computed tomography (CT) of the chest and abdomen in patients undergoing potentially curative resection of colorectal liver metastases. Seventy-six consecutive patients having undergone potentially curative resections of colorectal liver metastases in a single unit were followed up with a protocol of 3 monthly carcinoembryonic antigen and carbohydrate antigen 19-9 estimations and contrast-enhanced spiral CT of the chest, abdomen and pelvis for the first 2 years following surgery and 6 monthly thereafter. The median period of follow-up was 24 months (range 18-60). Recurrent tumour was classed as early if within 6 months of liver resection. Thirty-seven of the 76 patients (49%) developed recurrence on follow-up. Nineteen recurrences were in the liver alone (51%), 16 liver and extrahepatic (43%) and two extrahepatic alone (6%). Of the 19 patients with isolated liver recurrence, eight developed within 6 months of liver resection none of which were resectable. Of the 11 recurrences after 6 months, five (45%) were resectable. Of the 37 recurrences, CT indicated recurrence despite normal tumour markers in 19 patients. Tumour markers suggested recurrence before imaging in 12 and concurrently with imaging in 6. In the 12 patients who presented with elevated tumour markers before imaging, there was a median lag period of 3 months (range 1-21) in recurrence being detected on further serial imaging. Seventeen patients who developed recurrence had normal tumour markers before initial resection of their liver metastases. Of these 17, 10 (58%) had an elevation of tumour markers associated with recurrence. Over a median follow-up of 2 years following liver resection, the use of CT or tumour markers alone would have failed to demonstrate early recurrence in 12 and 18 patients respectively. A combination of tumour markers and CT detected significantly more (P < 0.05) recurrence than either modality alone. Tumour markers and CT should be used in combination in the follow-up of patients with resected colorectal liver metatases, including patients whose markers are normal at the time of initial liver resection.