Comparison of modified wet suction technique and dry suction technique in endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for solid lesions: study protocol for a randomized controlled trial

Abstract

Background: Several suction techniques have been developed recently to enhance tissue acquisition when sampling solid lesions using endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). The aim of this study is to determine whether a new modified wet suction technique (MWST) compared with the conventional dry suction technique (DRST) shall present better outcomes with respect to diagnostic yield and specimen quality of solid lesions in the intra-abdomen and mediastinum.

Methods/design: This is a single-blind, randomized, controlled, superiority trial conducted at four large tertiary care centers in China. Two hundred and ninety-six patients with solid lesions referred for EUS-FNA will be randomly assigned to group A, using DRST for the first pass, or group B, using MWST for the first pass in a ratio of 1:1. Following a 2 × 2 cross-over design, the pass sequence for group A is DRST, MWST, DRST, MWST. For group B, the pass sequence is MWST, DRST, MWST, DRST. All procedures will be performed by experienced echoendoscopists, and the patients and assessors (cytologists and pathologists) will be blinded during the entire study. The primary outcome measure is the diagnosis yield. Secondary outcome measures are specimen quality, including assessment of quantity of cell, tissue integrity, and blood contamination.

Discussion: To our knowledge, this is the first large-scale randomized controlled trial to compare MWST with DRST when sampling solid lesions in the intra-abdomen and mediastinum. The results may contribute to future multicenter clinical trials in standardizing suction techniques during EUS-FNA.

Trial registration: Clinical Trials.gov, NCT02789371 . Retrospectively registered on 6 June 2016.

Keywords: Diagnostic yield; Dry suction technique; EUS-FNA; Modified wet suction technique; Solid lesions.

Conflict of interest statement

Ethics approval and consent to participate

The study obtained ethics approval from the ethics committee of Tongji Medical College, Huazhong University of Science and Technology (IORG no., IORG0003571) on 4 May 2016. Written informed consent will be obtained from each participant or from each participant’s legally responsible relative prior to trial participation.

Consent for publication

Not applicable

Competing interests

The authors declare that they have no competing interests.

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Figures

Fig. 1

CONSORT flowchart illustrating the randomization and recruitment process in the study. 1 DRST, dry suction technique. 2MWST, modified wet suction technique. 3 Each slide will be assessed by two independent experts. The cytologists and pathologists will follow the protocol to assess the samples and will be blinded as to which technique was used for which specimen. 4 Four follow-up points are scheduled after the biopsy (1, 12, 24, and 48 weeks after the operation); thereafter, follow-ups will be conducted via telephone interviews or outpatient interviews. Once the surgical pathologic results are obtained, we will stop the follow-up sessions.

Fig. 2

Standard protocol items (SPIRIT): schedule for data collection. 1Coagulation routine tests: prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen, international normalized ratio. 2Blood biochemistry tests: aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, creatinine, alkaline phosphatase, lipase, amylase. 3Blood tumor markers tests: carcinoembryonic antigen, carbohydrate antigen 19-9, carbohydrate antigen 72-4, alpha fetal protein, squamous cell carcinoma antigen, neuron-specific enolase. 4Clinical signs include pain, weight loss, cachexia, etc. EUS, endoscopic ultrasound