Dry suction versus wet suction technique of endoscopic ultrasound-guided fine-needle biopsy for diagnosis of solid pancreatic lesions: study protocol of a multicenter randomized controlled non-inferiority trial

Abstract Background Studies have shown that the wet suction technique in endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) generates better histological diagnostic accuracy and specimen quality than the dry suction technique. However, conclusions of wet suction on the diagnostic accuracy of endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) are still controversial. Besides, the optimal number of passes for EUS-FNB has not been determined. We aimed to design a large multicenter randomized trial to compare the diagnostic accuracy of dry suction versus wet suction technique in solid pancreatic lesions (SPLs) using 22G Franseen needles and determine the optimal number of passes required for EUS-FNB. Methods This is a multi-center open-label, randomized controlled non-inferiority trial with two parallel groups. Two hundred patients with SPLs will undergo EUS-FNB using 22G Franseen needles in 4 tertiary hospitals in China and will be randomly assigned to the dry suction group and wet suction group in a ratio of 1:1. The primary endpoint is diagnostic accuracy. Secondary endpoints include the optimal number of needle passes, sensitivity, specificity, specimen quality, cytological diagnoses, time of the procedure, and incidence of complications. Discussion This study has been designed to determine (i) whether EUS-FNB using 22G Franseen needle with dry suction is non-inferior to wet suction in terms of diagnostic accuracy and (ii) the optimal number of passes during EUS-FNB of SPLs using 22G Franseen needle. Trial registration ClinicalTrials.gov NCT05549856. Registered on September 22, 2022.