Endoscopic Ultrasound-Guided Fine Needle Biopsy Using 22-Gauge Franseen Needle for the Histological Diagnosis of Solid Lesions: A Multicenter Prospective Pilot Study

Background Recently, a novel 22-gauge needle with three symmetric needle points and crown-shaped cutting heels, known as a Franseen needle, has been developed for endoscopic ultrasound-guided fine needle biopsy (EUS-FNB). Aim To assess the histological material acquisition rate and histological diagnostic capability of the 22-gauge Franseen needle (AC22) during EUS-FNB for solid lesions. Methods This study was designed as an open-label, multicenter, prospective, single-arm pilot study of EUS-FNB using AC22 for the diagnosis of solid lesions. Three passes of FNB using AC22 were performed for all lesions. The primary endpoints were the histological material acquisition rate and histological diagnostic capability. The secondary endpoints were the technical success rate, quality of histological samples, number of passes for diagnosis, and safety. Results Between September 2017 and May 2018, 75 patients were enrolled. The final diagnoses were malignancy in 65 and benign in 10. Three passes of FNB were technically successful in all patients. The sensitivity, specificity, and accuracy for the malignancy of histological analyses were 92.3% (60/65), 100% (10/10), and 93.3% (70/75), respectively, for the first pass and 95.4% (62/65), 100% (10/10), and 96% (72/75), respectively, for combined three passes. The diagnostic yield plateaued after the second pass. Sufficient tissue samples for histological interpretation were obtained in 96% (72/75) and 100% (75/75) patients for the single pass and combined three passes, respectively. Two patients (2.7%) developed mild pancreatitis as an adverse event. Conclusion EUS-FNB using AC22 showed high histological diagnostic capability with the high first pass yield.