Showing papers by "Brian R. Davidson published in 2008"
TL;DR: 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.
Abstract: 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.
374 citations
TL;DR: In this paper, the authors discuss the evidence for remote intra-organ preconditioning (RIPC), underlying mechanisms and possible clinical applications of RIPC, and the effective use of remote IPC needs to be investigated in clinical settings.
336 citations
TL;DR: The presence of UC post‐ LT, and the need for maintenance steroids post‐LT, which is an independent factor, are associated with rPSC, and these findings could help elucidate a possible mechanism of PSC pathogenesis.
174 citations
TL;DR: 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.
Abstract: 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.
172 citations
TL;DR: 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, and is likely to save costs.
Abstract: BackgroundAlthough day-case elective laparoscopic cholecystectomy can save bed costs, its safety remains to be established.ObjectivesTo assess the safety and benefits of day-case surgery compared to overnight stay in patients undergoing elective laparoscopic cholecystectomy.Search strategyWe 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 criteriaOnly 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 analysisWe 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 resultsFive 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' conclusionsDay-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.
88 citations
TL;DR: There is currently no evidence to support or refute the use of ischaemic preconditioning in donor liver retrievals, with no statistically significant difference in mortality, initial poor function, primary graft non-function, or re-transplant.
Abstract: 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.
76 citations
TL;DR: In vivo spectral abnormalities in cirrhosis are consistent with alterations in phospholipid metabolism and quantity of endoplasmic reticulum, however, in individual patients the biopsy results do not always mirror in vivo findings.
Abstract: In vivo 31P magnetic resonance spectroscopy (MRS) provides direct biochemical information on hepatic metabolic processes. To assess in vivo changes in hepatic 31P MRS in liver transplant candidates, we studied 31 patients with cirrhosis of varying aetiology; 14 with compensated cirrhosis (Pugh's score <7) and 17 with decompensated cirrhosis (Pugh's score <8). Underlying cellular abnormalities were characterised using in vitro31P MRS and electron microscopy. In vitro spectra were obtained from liver extracts, freeze-clamped at recipient hepatectomy, from all subjects. Electron microscopy of liver tissue was also performed in 17 cases. Relative to nucleotide triphosphates, elevations in phosphomonoesters and reductions in phosphodiesters were observed in vivo with worsening liver function. In vitro spectra showed elevated phosphoethanolamine and phosphocholine, and reduced glycerophosphorylethanolamine and glycerophosphorylcholine, mirroring the in vivo changes, but no distinction was noted between compensated and decompensated cirrhosis. With electron microscopy, functional decompensation was associated with reduced endoplasmic reticulum in parenchymal liver disease, but elevated levels in biliary cirrhosis. We conclude that in vivo spectral abnormalities in cirrhosis are consistent with alterations in phospholipid metabolism and quantity of endoplasmic reticulum. However, in individual patients the biopsy results do not always mirror in vivo findings.
66 citations
TL;DR: TIPS may improve portal supply to the graft and reduce collateral flow, improving function, which may account for the improved adjusted graft and patient survival by Cox regression at 12 months.
61 citations
TL;DR: The first reported liver transplant patient with Acanthamoeba cerebral abscess was presented, made in brain tissue removed at decompressive frontal lobectomy, and successfully treated with a 3‐month course of co‐trimoxazole and rifampicin.
55 citations
TL;DR: Two-stage hepatectomy combined with systemic chemotherapy and portal vein embolisation selectively can produce long-term survival in patients with multiple bilobar colorectal liver metastases.
Abstract: 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
55 citations
TL;DR: Based on evidence from only one high-bias risk trial, it appears that early laparoscopic cholecystectomy (< 24 hours of diagnosis of biliary colic) decreases the morbidity during the waiting period for elective laparoscopy, decreases the rate of conversion to open choleCystectomy, decreases operating time, and decreases hospital stay.
Abstract: BackgroundBiliary colic is one of the commonest indications for laparoscopic cholecystectomy. Laparoscopic cholecystectomy involves several months of waiting if performed electively. However, patients can develop life-threatening complications during this waiting period.ObjectivesTo assess the benefits and harms of early versus delayed laparoscopic cholecystectomy for patients with biliary colic due to gallstones.Search strategyWe searched The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Control led Trials in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until March 2008.Selection criteriaWe included only randomised clinical trials irrespective of language and publication status.Data collection and analysisTwo authors independently extracted the data. We intended to calculate the risk ratio, risk difference with 95% confidence intervals (CI) for dichotomous outcomes, and weighted mean difference (WMD) with 95% CI for continuous outcomes using RevMan 4.2 based on intention-to-treat analysis.Main resultsOnly one trial including 75 patients, randomised to early laparoscopic cholecystectomy (less than 24 hours of diagnosis) (n = 35) and delayed laparoscopic cholecystectomy (mean waiting period of 4.2 months) (n = 40), qualified for this review. This trial was of high risk of bias. During the waiting period in the delayed group (mean 4.2 months), the complications that the patients suffered included severe acute pancreatitis resulting in mortality (1), empyema of gallbladder (1), gallbladder perforation (1), acute cholecystitis (2), cholangitis (2), obstructive jaundice (2), and recurrent biliary colic requiring hospital visits (5). The rate of conversion to open cholecystectomy was lower in the early group (0%) than the delayed group (8/ 40 or 20%) (p = 0.0172). There was a statistically significant shorter operating time and hospital stay in the early group than the delayed group (WMD - 14.80 minutes, 95% CI -18.02 to -11.58 and -1.25 days, 95% CI -2.05 to - 0.45 respectively). Fourteen patients (35%) required 18 hospital admissions for symptoms related to gallstones during the mean waiting period of 4.2 months in the delayed group. This is equivalent to 11 admissions per 100 persons per month.Authors' conclusionsBased on evidence fromonly one high- bias risk trial, it appears that early laparoscopic cholecystectomy (< 24 hours of diagnosis of biliary colic) decreases the morbidity during the waiting period for elective laparoscopic cholecystectomy, decreases the rate of conversion to open cholecystectomy, decreases operating time, and decreases hospital stay. Further randomised clinical trials are necessary to confirm or refute this finding.
TL;DR: Tumour differentiation did not add significantly to prediction of HCC recurrence in this cohort, and diameter of the largest nodule remained a significant risk for recurrence.
Abstract: 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).
TL;DR: Survival rates are low in patients with positive lymph nodes draining the liver irrespective of whether they are detected by routine lymphadenectomy or by macroscopic involvement, and there is no evidence of survival benefit for routine or selective lymphadectomy.
Abstract: Background. Hepatic lymph node involvement is generally considered a contraindication for liver resection performed for colorectal liver metastases. However, some advocate hepatic lymphadenectomy in the presence of macroscopic involvement and others routine lymphadenectomy. The aim of this review is to assess the role of lymphadenectomy in resection of liver metastases from colorectal cancer. Methods. Medline, Embase and Central databases were searched using a formal search strategy. Trials with survival data with a minimum follow-up of 1 year were considered for inclusion. Meta-analysis was performed using Revman. Results. A total of 4230 references were identified. Ten reports of nine studies including 926 patients qualified for the review. The prevalence of nodal metastases after routine lymphadenectomy was 16.3%. The overall 3-year and 5-year survival rates in node-positive patients were 9/151 (11.3%) and 2/137 (1.5%), respectively, compared to 3-year and 5-year survival rates of 424/787 (53.9%) and 246/767 (32.1%) in node-negative patients. The odds ratios for 3-year and 5-year survivals in node positive disease compared to node-negative disease were 0.12 (95% CI 0.06 to 0.24) and 0.08 (95% CI 0.03 to 0.22). There was no randomized controlled trial which assessed the survival benefit of routine or “selective” lymphadenectomy. Conclusion. Currently, there is no evidence of survival benefit for routine or selective lymphadenectomy. Survival rates are low in patients with positive lymph nodes draining the liver irrespective of whether they are detected by routine lymphadenectomy or by macroscopic involvement. Further trials in this patient group are required.
TL;DR: 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.
Abstract: 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.
TL;DR: There is currently no clear evidence that the TLM is beneficial in human islet transplantation, but it may improve the preservation of marginal organs and improved oxygenation and preservation of cellular bioengertics is thought to be the main underlying mechanism.
TL;DR: There is currently no clear evidence that the TLM is beneficial in human islet transplantation, but it may improve the preservation of marginal organs.
Abstract: There are conflicting reports about the effectiveness of perfluorocarbons used in the two-layer method (TLM) of pancreas preservation for human islet transplantation. The mechanism of action is unclear and the optimal role of this method uncertain. The study design was a meta-analysis of the evidence that TLM improves islet isolation outcomes. Pubmed, CENTRAL, EMBASE, Science Citation Index, and BIOSIS were searched electronically in January 2008. After selecting the relevant human trials for meta-analysis data relating to donor variables, study design, primary and secondary islet isolation outcomes were extracted. Electronic searches identified eight unique citations, describing 11 human studies that were eligible for the meta-analysis. When comparing TLM with preservation in University of Wisconsin (UW) solution, there was a statistically significant higher islet yield [WMD 711.55, 95% confidence interval (CI) 140.03-1283.07] in the TLM group. The proportion of transplantable preparations obtained was not significantly different (OR 1.30, 95% CI 0.89-1.88) between the two groups. The rate of successful islet isolations for marginal organs was higher in the TLM group (OR 6.69, 95% CI 1.80-24.87). Improved oxygenation and preservation of cellular bioengertics is thought to be the main underlying mechanism, although no single mechanism has yet been confirmed. There is currently no clear evidence that the TLM is beneficial in human islet transplantation. It may improve the preservation of marginal organs.
TL;DR: LAT very rarely induces complete necrosis; the amount of necrosis seems to depend on the growth pattern of the tumours and not on the type of previous LAT; the tumour size, measured at explant, is the only variable significantly related to recurrence.
Abstract: Background and objective Loco-ablation therapy (LAT) has become standard treatment for patients with HCC who are candidates for liver transplantation (LT). The aim of this study was: to evaluate if LAT was able to induce complete necrosis of tumour mass; to determine the tumour recurrence rate after LT and factors associated with recurrence. Patients The percentage and the distribution of necrosis in 116 HCC nodules of 61 patients with (26 patients) and without (35 patients) previous types of LAT were examined in explanted livers. Results Total necrosis was found only in 7% of treated nodules, and 42% of these showed absence of necrosis. The amount of necrosis was significantly related to the gross appearance of HCC: a single nodule with smaller adjacent satellite nodules showed a higher percentage of necrosis. No relation was found between the amount of necrosis and the type of LAT. Recurrence was observed in 11.5% and 8.5% of patients with and without previous LAT, respectively (P = ns). Conclusions LAT very rarely induces complete necrosis; the amount of necrosis seems to depend on the growth pattern of the tumour and not on the type of previous LAT; the tumour size, measured at explant, is the only variable significantly related to recurrence.
TL;DR: None of the diagnostic tests had sufficient diagnostic accuracy to reliably separate patients with benign from malignant biliary strictures, and there is no trial evidence demonstrating benefit in obtaining a preoperative histological diagnosis of CCA.
Abstract: 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.
TL;DR: This case highlights another situation where there may be difficulty in differentiating Mirizzi syndrome from biliary tract cancer.
Abstract: Introduction
This is the first case report of Mirizzi syndrome associated with hepatic artery pseudoaneurysm.
TL;DR: Plasma TuM2-PK is commonly elevated in patients with CLM and remains elevated after liver resection, but levels do not correlate with tumour volume, number or differentiation.
Abstract: Background The currently available tumour markers used in the management of patients with colorectal metastases are of limited value. Tumour M2-pyruvate kinase (TuM2-PK), a tumour-associated isoenzyme of pyruvate kinase, is elevated in patients with gastrointestinal cancer. This study has measured TuIVI2-PK levels in patients before and after resection of colorectal liver metastases (CLM).Materials and methods Fifty patients with CLM and no local residual disease had TuM2-PK levels measured before liver resection. In 20 patients, TuM2-PK levels were repeated at 2 weeks, 5 weeks and 5 months after resection. Plasma levels were analysed by enzyme-linked immunosorbent assay (ScheBo, Giessen, Germany). Carcinoembryonic antigen (CEA) and CA19-9 levels were measured at the same time periods by electrochemiluminescence immunoassay. CEA, CA19-9 and TuM2-PK levels were compared with the tumour number, volume, differentiation and stage. Cut-off values used for TuM2-PK, CEA and CA19-9 were 15 IU/ml, 10 ng/ml and 391 U/ml, respectively.Results TuM2-PK was elevated in 68%, CEA in 62% and CA19-9 in 40% of patients with CLM. TuM2-PK+CEA was elevated in 88% and TuM2-PK + CA19-9 in 78% of patients. A significant correlation was observed between tumour volume and CEA (r= 0.34, P< 0.05) and CA19-9 (r= 0.49, P<0.005). TuM2-PK levels did not show a significant correlation with tumour differentiation, volume or the number of metastases. At 2 weeks after liver resection, CEA and CA19-9 levels had decreased to normal value in 73 and 67% of patients, respectively, but TuM2-PK remained elevated in all patients. At 5 weeks, TuM2-PK, CEA and CA19-9 levels decreased to normal in 64, 93 and 70% of patients, respectively, and at 5 months levels were normal in 58, 92 and 67%.Conclusion Plasma TuM2-PK is commonly elevated in patients with CLM. Levels do not correlate with tumour volume, number or differentiation. Levels remain elevated after liver resection, the cause of which requires further investigation.
TL;DR: Glycine prevented the significant reduction in bile flow seen in I/R at 6 h reperfusion, and there is evidence that glycine may protect against liver ischemia-reperfusion injury by inhibition of KC activity.
Abstract: Liver ischemia-reperfusion (I/R) injury is a major complication of liver resection and transplantation Cytokine release by activated Kupffer cells (KCs) play a central role in the inflammatory cascade of I/R injury There is evidence that glycine may protect against liver I/R injury by inhibition of KC activity However, its effect on bile flow, an established marker of hepatic function, and bile composition is not known A rabbit model of hepatic lobar warm I/R was used Under general anesthesia, the sham group (n = 6) underwent laparotomy alone for 7 h The I/R group (n = 6) underwent 60 min of left and median lobe inflow occlusion and 6 h of reperfusion The glycine + I/R group (n = 6) underwent a same procedure to controls after receiving glycine 5 mg/kg intravenous infusion for over 15 min Bile flow was collected, measured, and analyzed by proton magnetic resonance spectroscopy Glycine prevented the significant reduction in bile flow seen in I/R at 6 h reperfusion (1450 ± 114 vs 1083 ± 282 μL
01 Jan 2008
TL;DR: There is strong evidence to support RIPC, the underlying mechanisms and pathways need further clarification and the effective use of RIPC needs to be investigated in clinical settings.