Su1535 Direct Comparison Between ProcoreTM, and NonProcoreTM Fine Needle Aspiration Biopsy Needles: Does It Make Any Difference in Expert Hands? Jose-Guillermo De La Mora-Levy*, Cristian F. Florez-Sarmiento, Juan Octavio Alonso-Larraga, Juan O. Campuzano, Julio Sanchez Del Monte, Angelica Hernandez-Guerrero Gastrointestinal Endoscopy, Instituto Nacional de Cancerologia, Estado De Mexico, Mexico Background: Endoscopic Ultrasound (EUS-guided), Fine Needle Aspiration (FNA), has become the gold standard for sampling lesions from a variety of organs. A number of different techniques as well as a variety of needles are now available and are designed to obtain better diagnostic material. Since last year, a needle with two cutting edges, one similar to any other needle plus another one pointing backwards has been used (ProCoreTM, Cook-Medical, Limerick, Ireland). Preliminary reports suggest that this needle improves the yield of a positive diagnosis in a number of tissues (mainly pancreas and lymph nodes). Aim: to compare yield on adequate material of the procore needle compared to the regular EchoTip® needle in two consecutive cohorts of patients.Material & Methods: A comparative, retrospective study of a prospectively collected database of patients undergoing clinically indicated EUS-guided FNA in two separate time periods were included. During the first period, only the EchoTip® needle was used; during the second period, only ProCoreTM needles were used; all were 22 gauge. The technique was performed without aspiration. At most three samples were taken for each lesion and, a cytopathologist or technician were never available and the procedures were done by an experienced endosonographer ( 1000 FNA). The material was placed in glass slides and air dried, another part was sent in a preservative solution for cell block analysis. Only yield for diagnosis was calculated for each group. X2 with Yates adjustment or Fisher exact test were performed for comparison between groups. Results: A total of 103 patients with EUS-guided FNA were included, 51 using ProCoreTM and 52 using EchoTip® needles. A median of 2 pases were performed (range 14). The results were the following (Table): Conclusions: In the hands of expert endosonographists, the yield of ProCoreTM needles is not significantly different than the regular EchoTip®, and the results are similar to series without the presence of a cytopathologist.