After the reports by Vilmann and Grimm, endoscopic ultrasonography (EUS) guided fine needle aspiration (FNA) has become popular in the clinical fields, especially in the western world. However, EUS guided FNA is still a special examination in Japan, although it is also becoming popular. At the moment there is no standardization of EUS guided FNA in Japan. According to the questionnaire we put together, most experienced Japanese endosonographers commonly employed a 22 or 21 guage needle for EUS guided FNA. Optimally, EUS guided FNA is repeated to obtain enough tissue and to be confirmed histologically on site; however, it is confirmed macroscopically in more than half of the institutions included in the survey. All institutions used stylet, which is generally pulled back 1–3 cm during the puncture of the center of target lesion and commonly changed the pass way at each stroke. Negative pressure by the suction of 20 cc syringe has been used in most of institutions. Times of strokes varies from less than 10–30 in each institution. About pushing out the sample tissue, half of institutions used a stylet. As mentioned above, on site histo-cytologist with diff quick staining is optimal for EUS guided FNA; however, most of institutions do not allow this at the moment.
In order to widen EUS guided FNA we conducted multicenter study on the standardization of EUS guided FNA with statistical evidence.