EUS-FNA with on-site cytologic evaluation (OSE) has been the gold standard for tissue acquisition of pancreatic and intra-abdominal mass lesions (IAML). Recently, EUS-FNB or core biopsy has been shown to have equivalent diagnostic yield (DY) compared to EUS-FNA with OSE, but the differences in per patient cost and procedural time remain unclear. As such, we sought to compare per patient cost and procedural time between EUS-FNB and EUS-FNA for pancreatic masses and IAML. We performed a retrospective cohort study of EUS procedures for tissue sampling of solid pancreatic and IAML from 2013 to 2018. Patients were stratified into two subgroups: 1) EUS-FNB and 2) EUS-FNA with OSE. Patients who underwent both FNA and FNB were excluded. Primary outcomes included per patient costs and median procedure time. Costs were estimated using the Medicare cost to charge ratio and divided into procedural, anesthesia related, and pathology costs, as well as total cost. Total procedure time was defined as time from patient arrival into endoscopy suite until patient arrival in the recovery unit. Secondary outcomes included DY and rate of adverse events (AE). Cost data was analyzed using bivariate analysis to detect differences between groups. Multivariate logistic regression was used to identify differences in procedural time (SAS, v.9.4). A total of 305 patients underwent EUS-guided tissue acquisition (170 FNA and 135 FNB) for pancreas lesions and 333 patients (64 FNA and 269 FNB) for IAML. Procedural data between groups including needle passes, needle gauge, and AE are shown in Table 1. The DY of EUS-FNB was superior to EUS-FNA for pancreas (99.3% vs 94.7%, p=0.05) and IAML (98.5% vs 84.4%, p<0.01). EUS-FNB had a 30% shorter median procedure time compared to EUS-FNA for pancreatic lesions (50m [IQR: 41-64] vs 75m [IQR:59-101], p<0.01) and 33% shorter median procedure time compared to EUS-FNA for IAML (53m [IQR: 44-64] vs 75m [IQR: 59-101], p<0.01, Table 2). Mean procedure costs for FNA of pancreas lesions were $144 greater than FNB (p<0.01) while mean pathology costs of FNA were $107 lower than FNB (p<0.01) as FNB specimens were more likely to undergo additional tissue staining compared to FNA (43% vs 9%, p<0.01). There was no significant difference in procedure cost for FNA compared to FNB for IAML. EUS-FNB significantly reduces procedure time for tissue sampling with higher diagnostic yield compared to EUS-FNA with OSE for both pancreas and IAML. Marginal increase in pathology costs for EUS-FNB over EUS-FNA is best explained by better samples, enhancing tissue staining and diagnosis. In aggregate, EUS-FNB dominates EUS-FNA as there was no significant difference in total per patient costs. EUS-FNB should be considered first line for tissue acquisition in all cases where immediate diagnosis does not impact patient care.Table 2Procedure Time and Cost of EUS-FNB compared to EUS-FNA with OSE for Pancreatic and Intra-abdominal Mass LesionsView Large Image Figure ViewerDownload Hi-res image Download (PPT)