Comparison of specimen quality among the standard suction, slow-pull, and wet suction techniques for EUS-FNA: A multicenter, prospective, randomized controlled trial

BACKGROUND AND OBJECTIVES: Standard suction technique (SST), slow-pull technique (SPT), and wet suction technique (WEST) of EUS-FNA are designed to improve the diagnostic yields of solid and solid-cystic lesions. We conducted a multicenter, prospective, randomized crossover trial to compare SST, SPT, and WEST on specimen quality and diagnostic accuracy using a 22G needle. METHODS: Patients with solid or solid-cystic lesions referred for EUS-FNA at four tertiary hospitals from December 2017 to August 2019 were considered eligible. All lesions were sampled using a 22G needle by the three techniques performed consecutively in a randomized order. The primary outcome was quality of the specimen acquired by each technique regarding blood contamination, tissue integrity and cellularity for diagnosis, graded on a predefined scale. The secondary outcomes were the diagnostic yield of EUS-FNA and the incidence of adverse events. ClinicalTrial. gov registration number: NCT03567863. RESULTS: A total of 300 patients (mean age, 60.6 years, 188 men) were enrolled. WEST was superior (mean score 4.02 ± 1.51) over SST (3.67 ± 1.57, P = 0.018), but comparable to SPT (3.83 ± 1.55, P = 0.370) in overall specimen quality evaluation. WEST produced better tissue integrity (1.42 ± 0.74) and higher cellularity (1.32 ± 0.80) than SST and SPT. SPT (1.43 ± 0.69) was superior to SST (1.27 ± 0.72, P = 0.004) and WEST (1.28 ± 0.71, P = 0.006) in avoiding blood contamination. WEST achieved a diagnostic accuracy of 74.7%, higher than SST (64.4%, P = 0.007) and SPT (65.0%, P = 0.012). One bleeding event occurred with a pancreatic lesion. CONCLUSIONS: WEST was comparable to SPT and superior to SST in the overall quality of the specimen and achieved highest diagnostic yield.