Comparison of a 22-gauge Franseen-tip needle with a 20-gauge forward-bevel needle for the diagnosis of type 1 autoimmune pancreatitis: a prospective randomized, controlled multicenter study

Abstract Background and Aims Histologic diagnosis of autoimmune pancreatitis (AIP) using endosonographic ultrasound-guided fine-needle aspiration (EUS-FNA) is difficult. To address this issue, new fine-needle biopsy (FNB) needles were recently developed. Here, we prospectively evaluated 2 newly designed EUS-FNB needles for histologic evaluation in patients with type 1 AIP. Methods This was a prospective, randomized, multicenter trial comparing biopsy specimens obtained with a 22-gauge Franseen needle or a 20-gauge forward-bevel needle in patients with suspected of type 1 AIP. AIP was diagnosed according to international consensus diagnostic criteria. The primary endpoint was the sensitivity of EUS-FNB, and secondary endpoints were the amount of specimen obtained, histology of the pancreas based on evaluation of lymphoplasmacytic sclerosing pancreatitis (LPSP), and contribution of histologic findings to the diagnosis of AIP. Results A total of 110 patients were randomly assigned to the Franseen group (22-gauge Franseen needle) or the Forward-bevel group (20-gauge forward-bevel needle). EUS-FNB was successful in all patients. Nine patients were excluded due to diagnoses other than AIP. Compared with the forward-bevel needle, the Franseen needle obtained a significantly greater number of high-power fields. In 101 patients, 39 patients (78%) in the Franseen group and 23 patients (45%) in the Forward-bevel group were diagnosed with level 1 or 2 LPSP (P = .001). Thirty-six patients could not be diagnosed with type 1 AIP without EUS-FNB results. Conclusions The 22-gauge Franseen needle should be routinely used for histologic diagnosis of type 1 AIP.