Metal versus plastic stents for malignant biliary obstruction: an update meta-analysis.

BACKGROUND AND OBJECTIVE: The data on comparisons of stent patency, re-intervention rate and patient survival between metal and plastic stents in palliation of malignant biliary obstruction have never been pooled. We carry out a meta-analysis to summarise current evidence for clinical efficacy of metal and plastic stents in the treatment of malignant biliary obstruction. METHODS: A comprehensive search of several databases was conducted. A fixed-effects or random-effects model was used to pool data of all study endpoints. Sensitivity analysis and subgroup analysis (distal vs. hilar biliary obstruction) were also performed. RESULTS: Ten randomized clinical trials were identified. Compared with plastic stents, metal stents were associated with a significantly longer stent patency (HR=0.36; 95% CI: 0.28-0.47; I(2)=0%), fewer numbers of re-intervention (WMD=0.59; 95% CI: 0.28-0.90; I(2)=76.4%) and longer patient survival (HR=0.74; 95% CI: 0.64-0.85; I(2)=16.0%). These results were still significant by sensitivity analysis. All outcomes reached statistical significance except of the pooled WMD of number of re-intervention in the studies with hilar biliary obstruction. No publication bias was observed. CONCLUSIONS: Metal stents were associated with a significantly longer stent patency, lower re-intervention rate and longer patient survival in palliation of malignant biliary obstruction when compared to plastic stents.

Use of artificial neural network to predict esophageal varices in patients with HBV related cirrhosis.

BACKGROUND: Prediction of esophageal varices in cirrhotic patients by noninvasive methods is still unsatisfactory. OBJECTIVES: To evaluate the accuracy of an artificial neural network (ANN) in predicting varices in patients with HBV related cirrhosis. PATIENTS AND METHODS: An ANN was constructed with data taken from 197 patients with HBV related cirrhosis. The candidates for input nodes of the ANN were assessed by univariate analysis and sensitivity analysis. Five-fold cross validation was performed to avoid over-fitting. RESULTS: 14 variables were reduced by univariate and sensitivity analysis, and an ANN was developed with three variables (platelet count, spleen width and portal vein diameter). With a cutoff value of 0.5. The ANN model has a sensitivity of 96.5%, specificity of 60.4%, positive predictive value of 86.9%, negative predictive value of 86.5% and a diagnostic accuracy of 86.8% for the prediction of varices. CONCLUSIONS: An ANN may be useful for predicting presence of esophageal varices in patients with HBV related cirrhosis.

Endoscopic sphincterotomy plus endoprostheses in the treatment of large or multiple common bile duct stones.

BACKGROUND AND AIM: Little information is available on the outcomes of endoscopic sphincterotomy plus biliary stent placement without stone extraction as primary therapy at initial endoscopic retrograde cholangiopancreatography (ERCP) in the treatment of large or multiple common bile duct (CBD) stones. The aim of the present study was to study the effect of biliary stents and sphincterotomy as primary therapy for patients with choledocholithiasis. METHODS: Patients with large (≥20 mm) or multiple (≥3) CBD stones were retrospectively studied. The patients underwent endoscopic sphincterotomy and placement of plastic stents in the bile duct without stone extraction at the initial ERCP. Three or more months later, a second ERCP was carried out and stone removal was attempted. Differences in stone size and the largest CBD diameter before and after stenting were compared. Stone clearance and complications were also evaluated. RESULTS: 52 patients were enrolled. After a median of 124 days of biliary plastic stent placement the mean maximal stone diameter decreased from 16.6 mm to 10.0 mm (P < 0.01). The mean CBD diameter also decreased from 15.3 mm to 11.5 mm (P < 0.01). The total stone clearance at second ERCP was 94.2%, only 5.7% of which needed mechanical lithotripsy. COMPLICATIONS: pancreatitis in one (1.9%) at initial ERCP, cholangitis in two (3.8%) after 52 days and 84 days of placement of stent. No complications were recorded at second ERCP. CONCLUSIONS: Biliary plastic stents plus endoscopic sphincterotomy without stone extraction as primary therapy at initial ERCP is a safe and effective method in the management of large or multiple CBD stones.

Prediction of large esophageal varices in cirrhotic patients using classification and regression tree analysis.

OBJECTIVES: Recent guidelines recommend that all cirrhotic patients should undergo endoscopic screening for esophageal varices. That identifying cirrhotic patients with esophageal varices by noninvasive predictors would allow for the restriction of the performance of endoscopy to patients with a high risk of having varices. This study aimed to develop a decision model based on classification and regression tree analysis for the prediction of large esophageal varices in cirrhotic patients. METHODS: 309 cirrhotic patients (training sample, 187 patients; test sample 122 patients) were included. Within the training sample, the classification and regression tree analysis was used to identify predictors and prediction model of large esophageal varices. The prediction model was then further evaluated in the test sample and different Child-Pugh classes. RESULTS: The prevalence of large esophageal varices in cirrhotic patients was 50.8%. A tree model that was consisted of spleen width, portal vein diameter and prothrombin time was developed by classification and regression tree analysis achieved a diagnostic accuracy of 84% for prediction of large esophageal varices. When reconstructed into two groups, the rate of varices was 83.2% for high-risk group and 15.2% for low-risk group. Accuracy of the tree model was maintained in the test sample and different Child-Pugh classes. CONCLUSIONS: A decision tree model that consists of spleen width, portal vein diameter and prothrombin time may be useful for prediction of large esophageal varices in cirrhotic patients.

Prediction of large esophageal varices in cirrhotic patients using classification and regression tree analysis

OBJECTIVES: Recent guidelines recommend that all cirrhotic patients should undergo endoscopic screening for esophageal varices. That identifying cirrhotic patients with esophageal varices by noninvasive predictors would allow for the restriction of the performance of endoscopy to patients with a high risk of having varices. This study aimed to develop a decision model based on classification and regression tree analysis for the prediction of large esophageal varices in cirrhotic patients. METHODS: 309 cirrhotic patients (training sample, 187 patients; test sample 122 patients) were included. Within the training sample, the classification and regression tree analysis was used to identify predictors and prediction model of large esophageal varices. The prediction model was then further evaluated in the test sample and different Child-Pugh classes. RESULTS: The prevalence of large esophageal varices in cirrhotic patients was 50.8 percent. A tree model that was consisted of spleen width, portal vein diameter and prothrombin time was developed by classification and regression tree analysis achieved a diagnostic accuracy of 84 percent for prediction of large esophageal varices. When reconstructed into two groups, the rate of varices was 83.2 percent for high-risk group and 15.2 percent for low-risk group. Accuracy of the tree model was maintained in the test sample and different Child-Pugh classes. CONCLUSIONS: A decision tree model that consists of spleen width, portal vein diameter and prothrombin time may be useful for prediction of large esophageal varices in cirrhotic patients.

Predictors of esophageal varices in patients with HBV-related cirrhosis: a retrospective study.

BACKGROUND: All patients with liver cirrhosis are recommended to undergo an evaluation of esophageal varices (EV) to assess their risk of bleeding. Predicting the presence of EV through non-invasive means may reduce a large number of unnecessary endoscopies. This study was designed to develop a predictive model for varices in patients with Hepatitis B virus-related cirrhosis. METHODS: The retrospective analysis was performed in 146 patients with Hepatitis B virus-related cirrhosis. The data were assessed by univariate analysis and a multivariate logistic regression analysis. In addition, the receiver operating characteristic curves were also applied to calculate and compare the accuracy of the model and other single parameters for the diagnosis of esophageal varices. RESULTS: We found the prevalence of EV in patients with Hepatitis B virus-related cirrhosis to be 74.7%. In addition, platelet count, spleen width, portal vein diameter and platelet count/spleen width ratio were significantly associated with the presence of esophageal varices on univariate analysis. A multivariate analysis revealed that only the spleen width and portal vein diameter were independent risk factors. The area under the receiver operating characteristic curve of regression function (RF) model, which was composed of the spleen width and portal vein diameter, was higher than that of the platelet count. With a cut-off value of 0.3631, the RF model had an excellent sensitivity of 87.2% and an acceptable specificity of 59.5% with an overall accuracy of 80.1%. CONCLUSION: Our data suggest that portal vein diameter and spleen width rather than platelet count may predict the presence of varices in patients with Hepatitis B virus-related cirrhosis, and that the RF model may help physicians to identify patients who would most likely benefit from screenings for EV.

[Study on the value of Helieobacter pylori (H. pylori) stool antigen immunocard STAT in the diagnosis of H. pylori infection: a meta-analysis].

OBJECTIVE: To evaluate the accuracy of the Helicobacter pylori (H. pylori) stool antigen (HpSA) test and ImmunoCard STAT HpSA in the primary diagnosis of H. pylori infection. METHODS: We searched Medline (1966-2007.4), EMbase (1985-2007.4), Chinese Journals Full-text Database (CJFD) (1994-2007) etc. to identify Clinical Trials of ImmunoCard STAT HpSA for the primary diagnosis of H. pylori infection. Meta-analysis was conducted using the method recommended by The Cochrane Collaboration Center. RESULTS: Eleven trials were included with pooled sensitivity, pooled specificity as 0.93 (95% CI: 0.91-0.94), 0.93 (95% CI: 0.90- 0.95), respectively. Pooled positive likelihood ratio and pooled negative likelihood ratio were 12.01 (95% CI: 8.90-16.19), 0.08 (95% CI: 0.07-0.11), respectively with the pooled diagnostic odds ratio as 160.14(95% CI :100.43-255.34). The area under the summary receiver operating characteristic (SROC) was 0.974 +/- 0.005. CONCLUSION: ImmunoCard STAT HpSA appeared to be an accurate non-invasive method for the initial diagnosis of H. pylori infection.