Benefit of high negative pressure during endoscopic ultrasound-guided fine-needle aspiration with standard 22-gauge needles for pancreatic lesions: a retrospective comparative study.

Few studies are available on high negative pressure (HNP) during endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). This study compared the diagnostic yield between HNP and normal negative pressure (NNP) during EUS-FNA for solid pancreatic masses. Consecutive patients with pancreatic masses who underwent EUS-FNA using a 22-G needle with either HNP or NNP for both the first and second passes were retrospectively examined for diagnostic yield. Rapid on-site evaluation (ROSE) was unavailable at our center. The main outcome measures were the number of passes, diagnostic accuracy and quantity of histological samples. Two hundred patients underwent EUS-FNA (n = 97, HNP; n = 103, NNP) over a 22-month period. A significantly lower median number of passes was required for HNP than for NNP (2 vs. 3; p < .001). There was no significant difference in diagnostic accuracy between the two groups. The rate of obtaining a histological sample larger than a 10× power field in length was significantly higher for HNP than for NNP (76.4% vs. 59.6%; p = .0019). In the multivariate analysis, a large tumor size (>20 mm) and HNP were identified as factors influencing the acquisition of a larger histological sample. There was no significant difference in diagnostic accuracy between HNP and NNP. HNP required fewer passes without ROSE and was related to the acquisition of a larger histological sample. HNP may be useful when few samples are available for EUS-FNA with NNP or a larger histological sample is needed.