Background: Diagnostic accuracy and quality of smears obtained by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) are influenced by characteristics of suction and examined organ.
Aims and methods: Efficiency of EUS-FNA and quality of smears obtained by slow-pull (SP) and standard suction (SS) techniques was prospectively compared in the sampling of pancreatic (N = 56) and extrapancreatic (N = 145) tumors.
Results: SS technique resulted in a higher number of smear pairs both in pancreatic (1.74 vs. 3.19; p < 0.001) and extrapancreatic tumors (1.62 vs. 3.28; p < 0.001); however, it decreased the proportion of diagnostic smears (46.69% vs. 36.52%; p = 0.002 and 49.17% vs. 30.67%; p < 0.001) and increased the bloodiness (1.51 vs. 2.07; p < 0.001 and 1.48 vs. 2.05; p < 0.001). In pancreatic cancers, no difference was observed in terms of diagnostic accuracy (81.38% vs. 83.45%) and cellularity (1.44 vs. 1.27; p = 0.067); however, they were substantially higher in extrapancreatic tumors using SP technique (71.41% vs. 60.71% and 1.34 vs. 0.77; p < 0.001). Only SP technique resulted in a significant difference between examiners in terms of technical success rate and quality of smears without any decrease of diagnostic accuracy.
Conclusions: SP technique yields better quality smears independently from tumors characteristics; however, it shows significant examiner-dependency. SS technique reduces the diagnostic accuracy of sampling in extrapancreatic tumors.
Keywords: EUS-FNA; endoscopic ultrasound; pancreas; slow-pull; suction.