799 The Diagnostic Accuracy of 22- and 25-Gauge Needles in EUS-FNA of Solid Pancreatic Lesions: A Meta-Analysis

The Diagnostic Accuracy of 22and 25-Gauge Needles in EUSFNA of Solid Pancreatic Lesions: A Meta-Analysis Mohammad Madhoun, Sachin B. Wani, Dayna S. Early, Srinivas Gaddam, Amit Rastogi, William M. Tierney, John T. Maple Internal Medicine/ Digestive Diseases, University of Oklahoma Health Sciences Center, Oklahoma City, OK; Division of Gastroenterology, Washington University School of Medicine, St Louis, MO; Division of Gastroenterology and Hepatology, Veterans Affairs Medical Center and University of Kansas School of Medicine, Kansas City, MO Background: Several studies have assessed the performance characteristics of 22and 25-gauge needles in endoscopic ultrasound with fine needle aspiration (EUS-FNA) of pancreatic mass lesions, but most have failed to demonstrate superiority of either needle. Aim: Use meta-analysis to more robustly define the diagnostic accuracy of EUS-FNA for pancreatic masses using different gauge FNA needles. Methods: Studies were identified by searching ten medical databases including Ovid MEDLINE and the Cochrane Library Database for reports published between 1994 and 2010, using a reproducible search strategy comprised of relevant terms. References from retrieved articles and national meeting abstracts were also manually reviewed. Only studies comparing the overall diagnostic accuracy of 22-g vs 25-g EUS needles that used surgical histology or at least 6 months clinical follow up for a gold standard were included. Two reviewers independently scored the identified studies for methodology and abstracted pertinent data. When required, the original investigators were contacted to provide additional data. Pooling was conducted by both fixed-effects and random-effects models; results are presented from the random effects model when heterogeneity was significant. Diagnostic characteristics (sensitivity, specificity, positive and negative likelihood ratios) with 95% confidence interval (CI) were calculated. Results: Six studies (involving 1064 subjects) met the defined inclusion criteria. Of the 1064 patients, 678 subjects were in the 22-g group and 434 subjects were in the 25-g group (both needles were used in 48 patients). The performance characteristics of the two needles are contrasted in the accompanying table. The bivariate generalized linear random-effect model indicated that the 25-g needle is associated with a higher sensitivity (p 0.001) but comparable specificity (p 0.82) to the 22-g needle. The rate of needle malfunction was similar between the 2 groups (p 0.6). The nature of the data reporting did not allow for evaluation of some variables, such as diagnostic accuracy by anatomic sub-sites (e.g. head, body/ tail) and physician ease of use. Conclusions: This meta-analysis suggests 25gauge needle systems are more sensitive than 22-gauge needles for detecting pancreatic malignancy. Potential explanations include fewer bloody specimens, better needle traversal through firm masses, and technically easier access to lesions in the medial aspect of the pancreatic head and uncinate process while using the smaller caliber needle.