PMO-199Comparative study of sample adequacy of 25G vs 22G needle in endoscopic ultrasound (EUS) guided fine needle aspirate (FNA) of solid lesions

IntroductionOptimal needle size in achieving greatest diagnostic yield from EUS- guided FNA remains unclear.AimWe prospectively compared sample adequacy and safety of FNA of solid lesions between 25G and 22G (CookTM) needle at two tertiary centres.MethodsProspective data from two sites was collected between November 2008 and November 2011. A single operator alternated on a case-by-case basis between a 25G and 22G needle. A cytopathologist was present to assess adequacy of sample. The operator could switch needle size if required.Results152 patients undergoing 165 FNA were analysed (42M/30F, mean age 59). 76 patients had FNA with a 22 F needle and 76 with the 25F needle. Indications for EUS and FNA were pancreatic lesions 43%, lymph node enlargement 28%, biliary tract lesions 16%, submucosal lesion 8% and adrenal mass 1% and others 4%. Overall sample adequacy was 83.03% Adequacy per needle was 86.7% (22G) vs 79.2% (25G), p=0.22 Fischer's Exact test. The number of passes used in successful FNA was higher with use of the 25G needle compared with the 22G needle. (2.42 plus or minus 0.11 SEM vs 1.962 plus or minus 0.15 SEM, p=0.015, t-test). In particular the use of a 25G needle had a higher number of passes in pancreatic lesions compared with the 22G needle (2.58 plus or minus 0.16 SEM vs 1.94 plus or minus 0.14, p=0.004, t-test). There was no difference in adequacy between the needle sizes for each type of lesion sampled (Abstract PMO-199 table 1). Two needle exchanges (25G to a 22G) occurred. One complication of local site bleeding occurred (22G) that settled during the test.Abstract PMO-199 Table 1Lesion site22G25GFischer's exact testAdequate sampleInadequate sampleAdequate sampleInadequate sampleLymph node194203NSBiliary tract lesion92114NSPancreatic lesion333332NSSubmucosal lesion4225NSConclusionWe show no difference in sample adequacy between the two needle sizes. Use of a 25G results is associated with a higher number of passes in pancreatic FNA. Both needle sizes appear safe. Operator choice and ease of passage of needle into anatomical location may also influence choice of needle.Competing interestsNone declared.