Background & aim Endoscopic ultrasound guided fine needle biopsy (EUS-FNB) is the main tool for tissue acquisition and pathological diagnosis of pancreatic solid mass because of its superior accuracy and lower complication rate compared to CT-guided biopsy. However, the tissue adequacy and diagnostic yield remained unsatisfactory for 2 reasons. First, the conventional dry suction technique (DST) often get small tissue and 3 or more needle passes (i.e. biopsies) are required to obtain enough specimen. Second, blood contamination of the acquired tissue interfered with microscopic examination. Investigator aim to develop a novel technique to improve tissue acquisition within a fewer needle passes and avoid blood contamination by using heparin-based modified wet suction (H-MWST).~Methods This study will be a randomized crossover clinical trial. Patients with pancreatic solid mass indicated for EUS FNB will be enrolled. EUS FNB will be done by one experienced endoscopists in National Cheng Kung University Hospital. Patients will be randomized in a 1:1 ratio to receive EUS FNB with either dry suction technique (DST) or H-MWST first for the initial 2 needle passes, and then crossover to another suction technique for a total of 4 needle passes. The obtained tissue of each needle pass will be sent separately and examined by a pathologist who is unaware of the procedure order. Procedure related complications will be recorded. The primary outcome will be the acquired tissue quality quantified comparison. The secondary outcome will be the overall diagnostic yield, the specimen adequacy, and complication rate by each suction technique.
The objective of this randomized cross-over trial is to evaluate whether Heparin based wet suction technique, compared with dry suction technique, shall present a higher quality tissue core by using quantitative macroscopic and microscopic scale.