High and low negative pressure suction techniques in EUS-guided fine-needle tissue acquisition by using 25-gauge needles: a multicenter, prospective, randomized, controlled trial.

Background: EUS-guided FNA (EUS-FNA) has a high diagnostic accuracy for pancreatic diseases. However, although most reports have typically focused on cytology, histological tissue quality has rarely been investigated. The effectiveness of EUS-FNA combined with high negative pressure (HNP) suction was recently indicated for tissue acquisition, but has not thus far been tested in a prospective, randomized clinical trial.

Objective: To evaluate the adequacy of EUS-FNA with HNP for the histological diagnosis of pancreatic lesions by using 25-gauge needles.

Design: Prospective, single-blind, randomized, controlled crossover trial.

Setting: Seven tertiary referral centers.

Patients: Patients referred for EUS-FNA of pancreatic solid lesions. From July 2011 to April 2012, 90 patients underwent EUS-FNA of pancreatic solid masses by using normal negative pressure (NNP) and HNP with 2 respective passes. The order of the passes was randomized, and the sample adequacy, quality, and histology were evaluated by a single expert pathologist.

Intervention: EUS-FNA by using NNP and HNP.

Main Outcome Measurements: The adequacy of tissue acquisition and the accuracy of histological diagnoses made by using the EUS-FNA technique with HNP.

Results: We found that 72.2% (65/90) and 90% (81/90) of the specimens obtained using NNP and HNP, respectively, were adequate for histological diagnosis (P = .0003, McNemar test). For 73.3% (66/90) and 82.2% (74/90) of the specimens obtained by using NNP and HNP, respectively, an accurate diagnosis was achieved (P = .06, McNemar test). Pancreatitis developed in 1 patient after this procedure, which subsided with conservative therapy.

Limitations: This was a single-blinded, crossover study.

Conclusion: Biopsy procedures that combine the EUS-FNA with HNP techniques are superior to EUS-FNA with NNP procedures for tissue acquisition. (

Clinical Trial Registration Number: UMIN000005939.).