Furthermore, there is a more severe lack of results of the optimal expression technique despite their

possible influences, as suggested by Savides.9 Wani et al19 suggested that the use of a stylet may be useful for expression in a retrospective study that compared specimens obtained with and without a stylet. However, their main interest was the effects of a stylet as a needle traversed the gut wall, and the influences on expression were not discussed in detail. To the best of our knowledge, ours is the first randomized trial that prospectively compared the outcomes of 2 expression techniques prospectively. Currently, reinserting the stylet is a technique of the most common use, but it is labor intensive and may increase the risk of accidental needle stick injury.9, 10 and 11 Instead, air flushing is an easier and safer method to express aspirated material. However, AZD4547 solubility dmso the material

may spread out uncontrollably or clot, in addition to the risk of air-drying artifact. According to our results, air flushing in a slow, controlled fashion was superior to reinserting the stylet because bloodiness was lower in AF than in RS, although no air-drying artifact was noticed in either group. It is thought that the traditional technique of reinserting the stylet is still valuable because it can be reserved for cases SGI-1776 cell line in which aspirates cannot be expelled because of drying or clotting. This also is supported by the work of Sahai et al,20 in which ZD1839 the results of EUS-FNA with and without the stylet were prospectively compared in 135 solid masses. They expressed all of the samples by air flushing and discussed that clotting was rare if aspirated material was expelled without inordinate delay, which was in agreement with our observation. Our trial has a few limitations. At first, we used 2 kinds of needle gauges, which might have confounded results. However, it is unlikely that the influences were significant because a mass was punctured 4 times with the same needle, and each puncture was analyzed with generalized

estimating equations considering matching, which was supported by the supplementary data. Also, a large number of studies concluded that there were no differences in the diagnostic yield between 25-gauge and 22-gauge needles.21, 22, 23, 24, 25 and 26 With respect to another aspect of the design of the study that could prompt concern, there were no indications of any interactions involving order of sampling in our own separate examination of outcomes by order of administration. Second, immediate cytopathology evaluation, which is one of the important factors determining diagnostic yield, was not used in our trial.27 There are still many centers, like ours, that do not use immediate cytopathology evaluation because of increased procedure time and cost.