Comparison of 19-gauge aspiration needles with 20-gauge forward-bevel needles for the diagnosis of autoimmune pancreatitis: a prospective randomized, controlled study

Abstract

Background The diagnosis of autoimmune pancreatitis (AIP) is multidisciplinary, with the histopathological diagnosis providing crucial information for distinguishing AIP from malignancies. Here we compared the diagnostic performance and sample adequacy of 19-gauge endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) needles with 20-gauge endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) needles in patients with suspected AIP. Methods Patients with suspected AIP were enrolled between October 2018 and August 2020 into a single-center, prospective, randomized controlled study conducted at a tertiary medical center in Beijing. Participants were randomly assigned to undergo tissue specimen collection using either a 19-gauge EUS-FNA needle or a 20-gauge EUS-FNB needle. The primary endpoint was the sensitivity of the two needle types for diagnosing AIP, with secondary endpoints including diagnostic sufficiency of tissue obtained, technical success rate, adverse event rate, and contribution of histologic findings to the AIP diagnosis according to International Consensus Diagnostic Criteria. Results Forty-five patients were enrolled. There was no significant difference in diagnostic efficacy between the 19-gauge FNA needle and the 20-gauge forward-beveled FNB needle for AIP. Both needle types showed similar sensitivity and overall accuracy in diagnosing benign disease, including AIP. The median tissue length was comparable between the two groups, and there was no significant difference in adverse events. Conclusions There is no difference in diagnostic efficacy or core tissue acquisition between 19-gauge FNA and 20-gauge forward-beveled FNB needles for patients with AIP. The 19-gauge FNA needle may serve as an alternative in centers where FNB needles are not available. Trial Registration ClinicalTrials.gov NCT03753815