M.A. Javed

Meta-analysis of laparoscopic vs open liver resection for hepatocellular carcinoma

AIM To conduct a meta-analysis to determine the safety and efficacy of laparoscopic liver resection (LLR) and open liver resection (OLR) for hepatocellular carcinoma (HCC). METHODS PubMed (Medline), EMBASE and Science Citation Index Expanded and Cochrane Central Register of Controlled Trials in the Cochrane Library were searched systematically to identify relevant comparative studies reporting outcomes for both LLR and OLR for HCC between January 1992 and February 2012. Two authors independently assessed the trials for inclusion and extracted the data. Meta-analysis was performed using Review Manager Version 5.0 software (The Cochrane Collaboration, Oxford, United Kingdom). Pooled odds ratios (OR) or weighted mean differences (WMD) with 95%CI were calculated using either fixed effects (Mantel-Haenszel method) or random effects models (DerSimonian and Laird method). Evaluated endpoints were operative outcomes (operation time, intraoperative blood loss, blood transfusion requirement), postoperative outcomes (liver failure, cirrhotic decompensation/ascites, bile leakage, postoperative bleeding, pulmonary complications, intraabdominal abscess, mortality, hospital stay and oncologic outcomes (positive resection margins and tumor recurrence). RESULTS Fifteen eligible non-randomized studies were identified, out of which, 9 high-quality studies involving 550 patients were included, with 234 patients in the LLR group and 316 patients in the OLR group. LLR was associated with significantly lower intraoperative blood loss, based on six studies with 333 patients [WMD: -129.48 mL; 95%CI: -224.76-(-34.21) mL; P = 0.008]. Seven studies involving 416 patients were included to assess blood transfusion requirement between the two groups. The LLR group had lower blood transfusion requirement (OR: 0.49; 95%CI: 0.26-0.91; P = 0.02). While analyzing hospital stay, six studies with 333 patients were included. Patients in the LLR group were found to have shorter hospital stay [WMD: -3.19 d; 95%CI: -4.09-(-2.28) d; P < 0.00001] than their OLR counterpart. Seven studies including 416 patients were pooled together to estimate the odds of developing postoperative ascites in the patient groups. The LLR group appeared to have a lower incidence of postoperative ascites (OR: 0.32; 95%CI: 0.16-0.61; P = 0.0006) as compared with OLR patients. Similarly, fewer patients had liver failure in the LLR group than in the OLR group (OR: 0.15; 95%CI: 0.02-0.95; P = 0.04). However, no significant differences were found between the two approaches with regards to operation time [WMD: 4.69 min; 95%CI: -22.62-32 min; P = 0.74], bile leakage (OR: 0.55; 95%CI: 0.10-3.12; P = 0.50), postoperative bleeding (OR: 0.54; 95%CI: 0.20-1.45; P = 0.22), pulmonary complications (OR: 0.43; 95%CI: 0.18-1.04; P = 0.06), intra-abdominal abscesses (OR: 0.21; 95%CI: 0.01-4.53; P = 0.32), mortality (OR: 0.46; 95%CI: 0.14-1.51; P = 0.20), presence of positive resection margins (OR: 0.59; 95%CI: 0.21-1.62; P = 0.31) and tumor recurrence (OR: 0.95; 95%CI: 0.62-1.46; P = 0.81). CONCLUSION LLR appears to be a safe and feasible option for resection of HCC in selected patients based on current evidence. However, further appropriately designed randomized controlled trials should be undertaken to ascertain these findings.

Fatty acid ethyl ester synthase inhibition ameliorates ethanol-induced Ca2+-dependent mitochondrial dysfunction and acute pancreatitis

Objective Non-oxidative metabolism of ethanol (NOME) produces fatty acid ethyl esters (FAEEs) via carboxylester lipase (CEL) and other enzyme action implicated in mitochondrial injury and acute pancreatitis (AP). This study investigated the relative importance of oxidative and non-oxidative pathways in mitochondrial dysfunction, pancreatic damage and development of alcoholic AP, and whether deleterious effects of NOME are preventable. Design Intracellular calcium ([Ca2+]C), NAD(P)H, mitochondrial membrane potential and activation of apoptotic and necrotic cell death pathways were examined in isolated pancreatic acinar cells in response to ethanol and/or palmitoleic acid (POA) in the presence or absence of 4-methylpyrazole (4-MP) to inhibit oxidative metabolism. A novel in vivo model of alcoholic AP induced by intraperitoneal administration of ethanol and POA was developed to assess the effects of manipulating alcohol metabolism. Results Inhibition of OME with 4-MP converted predominantly transient [Ca2+]C rises induced by low ethanol/POA combination to sustained elevations, with concurrent mitochondrial depolarisation, fall of NAD(P)H and cellular necrosis in vitro. All effects were prevented by 3-benzyl-6-chloro-2-pyrone (3-BCP), a CEL inhibitor. 3-BCP also significantly inhibited rises of pancreatic FAEE in vivo and ameliorated acute pancreatic damage and inflammation induced by administration of ethanol and POA to mice. Conclusions A combination of low ethanol and fatty acid that did not exert deleterious effects per se became toxic when oxidative metabolism was inhibited. The in vitro and in vivo damage was markedly inhibited by blockade of CEL, indicating the potential for development of specific therapy for treatment of alcoholic AP via inhibition of FAEE generation.

Mechanism of mitochondrial permeability transition pore induction and damage in the pancreas: inhibition prevents acute pancreatitis by protecting production of ATP

Objective Acute pancreatitis is caused by toxins that induce acinar cell calcium overload, zymogen activation, cytokine release and cell death, yet is without specific drug therapy. Mitochondrial dysfunction has been implicated but the mechanism not established. Design We investigated the mechanism of induction and consequences of the mitochondrial permeability transition pore (MPTP) in the pancreas using cell biological methods including confocal microscopy, patch clamp technology and multiple clinically representative disease models. Effects of genetic and pharmacological inhibition of the MPTP were examined in isolated murine and human pancreatic acinar cells, and in hyperstimulation, bile acid, alcoholic and choline-deficient, ethionine-supplemented acute pancreatitis. Results MPTP opening was mediated by toxin-induced inositol trisphosphate and ryanodine receptor calcium channel release, and resulted in diminished ATP production, leading to impaired calcium clearance, defective autophagy, zymogen activation, cytokine production, phosphoglycerate mutase 5 activation and necrosis, which was prevented by intracellular ATP supplementation. When MPTP opening was inhibited genetically or pharmacologically, all biochemical, immunological and histopathological responses of acute pancreatitis in all four models were reduced or abolished. Conclusions This work demonstrates the mechanism and consequences of MPTP opening to be fundamental to multiple forms of acute pancreatitis and validates the MPTP as a drug target for this disease.

Early oral refeeding wisdom in patients with mild acute pancreatitis.

Objectives To evaluate the safety and efficacy of early oral refeeding (EORF) in patients with mild acute pancreatitis (AP) and to investigate the optimal duration to commence EORF. Methods A prospective, randomized, controlled trial was conducted in patients with mild AP. Patients with EORF (started oral feeding once they subjectively felt hungry) were compared with patients receiving routine oral refeeding (RORF) for time interval between disease onset and initiation of oral refeeding, total length of hospitalization (LOH), postrefeeding LOH, and adverse gastrointestinal events. Results There were 75 and 74 patients in the EORF group and the RORF group, respectively, with comparable baseline characteristics. Patients in the EORF group started refeeding significantly earlier than those in the RORF group (4.56 ± 1.53 vs 6.75 ± 2.29 days; P < 0.05). Moreover, patients in the EORF group had significantly shorter total (6.8 ± 2.1 vs 10.4 ± 4.1 days; P < 0.01) and post refeeding LOH (2.24 ± 0.52 vs 3.27 ± 0.61 days; P < 0.01). There was no significant difference in adverse gastrointestinal events between the 2 groups. Conclusion In patients with mild AP, EORF, with the subjective feeling of hunger, is safe, feasible, and reduces LOH.

Roux-en-Y versus Billroth I reconstruction after distal gastrectomy for gastric cancer: a meta-analysis.

AIM To conduct a meta-analysis to compare Roux-en-Y (R-Y) gastrojejunostomy with gastroduodenal Billroth I (B-I) anastomosis after distal gastrectomy (DG) for gastric cancer. METHODS A literature search was performed to identify studies comparing R-Y with B-I after DG for gastric cancer from January 1990 to November 2012 in Medline, Embase, Science Citation Index Expanded and the Cochrane Central Register of Controlled Trials in The Cochrane Library. Pooled odds ratios (OR) or weighted mean differences (WMD) with 95%CI were calculated using either fixed or random effects model. Operative outcomes such as operation time, intraoperative blood loss and postoperative outcomes such as anastomotic leakage and stricture, bile reflux, remnant gastritis, reflux esophagitis, dumping symptoms, delayed gastric emptying and hospital stay were the main outcomes assessed. Meta-analyses were performed using RevMan 5.0 software (Cochrane library). RESULTS Four randomized controlled trials (RCTs) and 9 non-randomized observational clinical studies (OCS) involving 478 and 1402 patients respectively were included. Meta-analysis of RCTs revealed that R-Y reconstruction was associated with a reduced bile reflux (OR 0.04, 95%CI: 0.01, 0.14; P < 0.00 001) and remnant gastritis (OR 0.43, 95%CI: 0.28, 0.66; P = 0.0001), however needing a longer operation time (WMD 40.02, 95%CI: 13.93, 66.11; P = 0.003). Meta-analysis of OCS also revealed R-Y reconstruction had a lower incidence of bile reflux (OR 0.21, 95%CI: 0.08, 0.54; P = 0.001), remnant gastritis (OR 0.18, 95%CI: 0.11, 0.29; P < 0.00 001) and reflux esophagitis (OR 0.48, 95%CI: 0.26, 0.89; P = 0.02). However, this reconstruction method was found to be associated with a longer operation time (WMD 31.30, 95%CI: 12.99, 49.60; P = 0.0008). CONCLUSION This systematic review point towards some clinical advantages that are rendered by R-Y compared to B-I reconstruction post DG. However there is a need for further adequately powered, well-designed RCTs comparing the same.

Short-term continuous high-volume hemofiltration on clinical outcomes of severe acute pancreatitis.

Objectives This study aimed to conduct a single-center prospective trial of short-term continuous high-volume hemofiltration (HVHF) in patients with predicted severe acute pancreatitis (SAP). Methods Patients with acute pancreatitis with Acute Physiology and Chronic Health Evaluation II scores of greater than 15 on admission between January 2008 and December 2010 were allocated to receive either optimal standard therapy or 72 hours of continuous HVHF on an alternate basis, beginning as soon as possible after admission. Biomarkers and clinical outcomes were compared between the 2 groups. Results A total of 61 patients received either conventional therapy (n = 29) or HVHF (n = 32). High-volume hemofiltration treatment was associated with a significant reduction in the incidence of renal failure (P = 0.013), infected pancreatic necrosis (P = 0.048), length of hospitalization (P = 0.005), mortality (P = 0.033), as well as duration of renal (P < 0.001), respiratory (P = 0.002), and hepatic failure (P = 0.001). Acute Physiology and Chronic Health Evaluation II score and C-reactive protein and interleukin 6 levels were significantly reduced after the start of HVHF on days 1, 3, and 7 (all, P < 0.05). Conclusions This study suggests that short-term HVHF may reduce local and systemic complications and mortality in patients with SAP with Acute Physiology and Chronic Health Evaluation score of greater than 15.

Validation of the moderate severity category of acute pancreatitis defined by determinant-based classification

BACKGROUND Recent international multidisciplinary consultation proposed the use of local (sterile or infected pancreatic necrosis) and/or systemic determinants (organ failure) in the stratification of acute pancreatitis. The present study was to validate the moderate severity category by international multidisciplinary consultation definitions. METHODS Ninety-two consecutive patients with severe acute pancreatitis (according to the 1992 Atlanta classification) were classified into (i) moderate acute pancreatitis group with the presence of sterile (peri-) pancreatic necrosis and/or transient organ failure; and (ii) severe/critical acute pancreatitis group with the presence of sterile or infected pancreatic necrosis and/or persistent organ failure. Demographic and clinical outcomes were compared between the two groups. RESULTS Compared with the severe/critical group (n=59), the moderate group (n=33) had lower clinical and computerized tomographic scores (both P<0.05). They also had a lower incidence of pancreatic necrosis (45.5% vs 71.2%, P=0.015), infection (9.1% vs 37.3%, P=0.004), ICU admission (0% vs 27.1%, P=0.001), and shorter hospital stay (15+/-5 vs 27+/-12 days; P<0.001). A subgroup analysis showed that the moderate group also had significantly lower ICU admission rates, shorter hospital stay and lower rate of infection compared with the severe group (n=51). No patients died in the moderate group but 7 patients died in the severe/critical group (4 for severe group). CONCLUSIONS Our data suggest that the definition of moderate acute pancreatitis, as suggested by the international multidisciplinary consultation as sterile (peri-) pancreatic necrosis and/or transient organ failure, is an accurate category of acute pancreatitis.

Small Molecule Inhibitors of Cyclophilin D To Protect Mitochondrial Function as a Potential Treatment for Acute Pancreatitis

Opening of the mitochondrial permeability transition pore (MPTP) causes mitochondrial dysfunction and necrosis in acute pancreatitis (AP), a condition without specific drug treatment. Cyclophilin D (CypD) is a mitochondrial matrix peptidyl-prolyl isomerase that regulates the MPTP and is a drug target for AP. We have synthesized urea-based small molecule inhibitors of cyclophilins and tested them against CypD using binding and isomerase activity assays. Thermodynamic profiles of the CypD/inhibitor interactions were determined by isothermal titration calorimetry. Seven new high-resolution crystal structures of CypD-inhibitor complexes were obtained to guide compound optimization. Compounds 4, 13, 14, and 19 were tested in freshly isolated murine pancreatic acinar cells (PACs) to determine inhibition of toxin-induced loss of mitochondrial membrane potential (ΔΨm) and necrotic cell death pathway activation. Compound 19 was found to have a Kd of 410 nM and a favorable thermodynamic profile, and it showed significant protection of ΔΨm and reduced necrosis of murine as well as human PACs. Compound 19 holds significant promise for future lead optimization.

Prediction of the severity of acute pancreatitis on admission by urinary trypsinogen activation peptide: a meta-analysis

AIM To undertake a meta-analysis on the value of urinary trypsinogen activation peptide (uTAP) in predicting severity of acute pancreatitis on admission. METHODS Major databases including Medline, Embase, Science Citation Index Expanded and the Cochrane Central Register of Controlled Trials in the Cochrane Library were searched to identify all relevant studies from January 1990 to January 2013. Pooled sensitivity, specificity and the diagnostic odds ratios (DORs) with 95%CI were calculated for each study and were compared to other systems/biomarkers if mentioned within the same study. Summary receiver-operating curves were conducted and the area under the curve (AUC) was evaluated. RESULTS In total, six studies of uTAP with a cut-off value of 35 nmol/L were included in this meta-analysis. Overall, the pooled sensitivity and specificity of uTAP for predicting severity of acute pancreatitis, at time of admission, was 71% and 75%, respectively (AUC = 0.83, DOR = 8.67, 95%CI: 3.70-20.33). When uTAP was compared with plasma C-reactive protein, the pooled sensitivity, specificity, AUC and DOR were 0.64 vs 0.67, 0.77 vs 0.75, 0.82 vs 0.79 and 6.27 vs 6.32, respectively. Similarly, the pooled sensitivity, specificity, AUC and DOR of uTAP vs Acute Physiology and Chronic Health Evaluation II within the first 48 h of admission were found to be 0.64 vs 0.69, 0.77 vs 0.61, 0.82 vs 0.73 and 6.27 vs 4.61, respectively. CONCLUSION uTAP has the potential to act as a stratification marker on admission for differentiating disease severity of acute pancreatitis.

TRO40303 Ameliorates Alcohol-Induced Pancreatitis Through Reduction of Fatty Acid Ethyl Ester–Induced Mitochondrial Injury and Necrotic Cell Death

Objectives Mitochondrial permeability transition pore inhibition is a promising approach to treat acute pancreatitis (AP). We sought to determine (i) the effects of the mitochondrial permeability transition pore inhibitor 3,5-seco-4-nor-cholestan-5-one oxime-3-ol (TRO40303) on murine and human pancreatic acinar cell (PAC) injury induced by fatty acid ethyl esters (FAEEs) or taurolithocholic acid-3-sulfate and (ii) TRO40303 pharmacokinetics and efficacy in experimental alcoholic AP (FAEE-AP). Methods Changes in mitochondrial membrane potential (&Dgr;&psgr;m), cytosolic Ca2+ ([Ca2+]c), and cell fate were examined in freshly isolated murine or human PACs by confocal microscopy. TRO40303 pharmacokinetics were assessed in cerulein-induced AP and therapeutic efficacy in FAEE-AP induced with palmitoleic acid and ethanol. Severity of AP was assessed by standard biomarkers and blinded histopathology. Results TRO40303 prevented loss of &Dgr;&psgr;m and necrosis induced by 100 &mgr;M palmitoleic acid ethyl ester or 500 &mgr;M taurolithocholic acid-3-sulfate in murine and human PACs. Pharmacokinetic analysis found TRO40303 accumulated in the pancreas. A single dose of 3 mg/kg TRO40303 significantly reduced serum amylase (P = 0.043), pancreatic trypsin (P = 0.018), and histopathology scores (P = 0.0058) in FAEE-AP. Conclusions TRO40303 protects mitochondria and prevents necrotic cell death pathway activation in murine and human PACs, ameliorates the severity of FAEE-AP, and is a candidate drug for human AP.