Experience of combined endoscopic percutaneous stenting with ultrasound guidance for drainage of pancreatic pseudocycts

The therapeutic options for treatment of pancreatic pseudocysts are numerous. We report our experience of combined endoscopic and ultrasound guided percutaneous stenting for pancreatic pseudocysts. Data were prospectively collected for 20 consecutive patients. All patients had undergone a standard technique of combined endoscopic and ultrasound guided percutaneous placement of double J stents, between a pancreatic pseudocyst and the stomach. Patients age ranged between 25 and 84 years. Thirteen of the pseudocysts were due to acute pancreatitis and 7 were due to chronic pancreatitis. The duration of the combined procedure was mean 50 min (range 30-95 min). The length of hospital stay was mean 5 days (range 2-77 days. Only two patients suffered postoperative complications; one was re-admitted 2 weeks following stenting with acute cholecystitis, the other suffering a perforated duodenal ulcer 3 weeks after stenting. There were two failures early in the series, both due to stent migration, these stents were of a small size, (4.7 French). Following this the stent size was increased to at least 7 French, no further failures occurred. There was no operative mortality for the series. Follow-up ranged between 6 months and 5 years. We conclude that a combined percutaneous and endoscopic cyst-gastrostomy stent is a safe and effective treatment for patients with suitably placed pseudocysts.     

An automated process for building reliable and optimal in vitro/in vivo correlation models based on Monte Carlo simulations

Many mathematical models have been proposed for establishing an in vitro/in vivo correlation (IVIVC). The traditional IVIVC model building process consists of 5 steps: deconvolution, model fitting, convolution, prediction error evaluation, and cross-validation. This is a time-consuming process and typically a few models at most are tested for any given data set. The objectives of this work were to (1) propose a statistical tool to screen models for further development of an IVIVC, (2) evaluate the performance of each model under different circumstances, and (3) investigate the effectiveness of common statistical model selection criteria for choosing IVIVC models. A computer program was developed to explore which model(s) would be most likely to work well with a random variation from the original formulation. The process used Monte Carlo simulation techniques to build IVIVC models. Data-based model selection criteria (Akaike Information Criteria [AIC], R2) and the probability of passing the Food and Drug Administration "prediction error" requirement was calculated. To illustrate this approach, several real data sets representing a broad range of release profiles are used to illustrate the process and to demonstrate the advantages of this automated process over the traditional approach. The Hixson-Crowell and Weibull models were often preferred over the linear. When evaluating whether a Level A IVIVC model was possible, the model selection criteria AIC generally selected the best model. We believe that the approach we proposed may be a rapid tool to determine which IVIVC model (if any) is the most applicable.     

Meta-analysis using individual patient data from randomised trials to assess the effectiveness of laparoscopic uterosacral nerve ablation in the treatment of chronic pelvic pain: a proposed protocol

Background  Currently, there are a number of clinical trials, but no international collaboration for collating research on effectiveness of laparoscopic uterosacral nerve ablation (LUNA) for alleviating chronic pelvic pain.
Objective  Meta-analysis was used by collecting individual patient data (IPD) from the existing trials, to provide a comprehensive assessment of the effectiveness of LUNA that will be generalisable in various clinical contexts.
Methods  IPD will be sought and collected from all relevant (both already finished and continuing) randomised trials identified through previous systematic reviews. After obtaining raw data and cleaning the database, analysis will be of all patients ever randomised based on the intention-to-treat principle using endpoints measured at 12 months following randomisation.
Proposal  We will update searches, contact all authors, obtain data in whatever form it can be provided, build a single database, produce results for individual studies, have them verified by original authors, explore of any heterogeneity and reasons behind it and finally pool all raw data in to a meta-analysis using appropriate statistical methods. The project will test the effectiveness of LUNA for women with chronic pelvic pain. It will also motivate collaborating primary investigators to undertake new primary studies to corroborate or improve upon the conclusions derived from the retrospective analysis.     

Serum CA19-9 measurement increases the effectiveness of staging laparoscopy in patients with suspected pancreatic malignancy

BACKGROUND/AIMS: Staging laparoscopy for suspected pancreatic neoplasia is not widely accepted due to its low yield. The aim of this study was to determine if serum carbohydrate antigen (CA19-9) levels could be used to improve the selection of patients for staging laparoscopy. METHODS: The data from a prospectively collected database (1997-2004) with 159 patients who had computed tomography-predicted resectable disease and who had undergone laparoscopic staging were analysed to determine if a low preoperative CA19-9 level (< or =150 kU/l, or < or =300 kU/l with a bilirubin >35 micromol/l) identified patients in whom laparoscopy was not useful. Results: The CA19-9 level was >150 kU/l in 96 patients of whom 75 (78%) were considered resectable following laparoscopic assessment. There were 63 patients with a CA19-9 < or =150 kU/l of whom 60 (95%) were considered resectable following laparoscopic assessment. The sensitivity, specificity, positive predictive value and negative predictive value for CA19-9 < or =150 kU/l in predicting that laparoscopic assessment would judge patients as resectable were 44, 88, 95 and 22%, respectively. A cut-off level of < or =300 kU/l in patients with a bilirubin >35 micromol/l produced values of 30, 94, 94 and 28%, respectively. By using CA19-9 < or =150 kU/l, laparoscopy could have been avoided in 40% of patients, increased to 55% of patients with adjustment for the presence of jaundice; concomitantly, the yield from laparoscopy would have been increased from 15 to 22 and 25%, respectively. Conclusion: Use of serum CA19-9 levels would increase the efficiency of laparoscopic staging in patients with suspected pancreatic malignancy.