Twenty versus 40 back-and-forth needle movements for endoscopic ultrasound-guided fine-needle biopsy of solid pancreatic masses: a prospective, crossover, randomized study

Background and aims In endoscopic ultrasound (EUS)-fine-needle biopsy (FNB) of solid pancreatic mass lesions, the number of times the needle moves back and forth within the lesion might affect the collection of the sample and the subsequent diagnostic accuracy. Thus, this study was designed to compare the diagnostic adequacy between different numbers of back-and-forth movements in EUS-FNB. Methods Fifty-five patients with solid pancreatic masses underwent EUS-FNB sampling with the needle (22-gauge) moved 20 times (MTT) and 40 times (MFT) randomly and sequentially for a total of four alternating passes. We compared the acquisition rate of appropriate and adequate specimens for histologic assessment and diagnostic accuracy. Results Finally, 55 patients (35 men and 20 women) were included in the study. We found that 56.4% (31/55) and 60% (33/55) of the specimens obtained using MTT and MFT, respectively, could be adequately diagnosed histologically ( P = 0.815, McNemar test). The diagnostic accuracy of MTT and MFT was 72.7% (40/55) and 80% (44/55), respectively ( P = 0.289, McNemar test). The overall diagnostic accuracy was 89.1%. Conclusion There was no significant statistical difference between the histopathological diagnostic samples obtained in MTT and those obtained in MFT. Therefore, a large number of back-and-forth movements of the needle should be avoided during EUS-FNB, which can help reduce the operation time and may reduce the risk of intraoperative and postoperative complications (Clinical trial registration number: ChiCTR2000031106).