Background and study aims: Whether there is an advantage in using the wet-suction (WS) or slow-pull (SP) technique during endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) with new generation needles is unknown. We aimed to compare EUS-FNB performed with WS versus SP technique.
Patients and methods: Multicenter, randomized, single-blind, cross-over trial including patients with solid lesions ≥1cm. Four needle passes with 22G Fork-tip or Franseen-type needles were performed, alternating WS and SP technique in a randomized order. The primary aim was the histologic yield (samples containing an intact piece of tissue of at least 550μm). Secondary endpoints were sample quality (tissue integrity and blood contamination), diagnostic accuracy, and adequate tumor fraction.
Results: Overall, 210 patients with 146 pancreatic and 64 nonpancreatic lesions were analyzed. A tissue core was retrieved in 150 (71.4%) and 129 (61.4%) cases using the WS and the SP, respectively (p=0.03). The mean tissue integrity score was higher using the WS (p=0.02), as was the blood contamination of samples (p<0.001). In the two subgroups of pancreatic and non-pancreatic lesions, tissue core rate and tissue integrity score were not statistically different using the two techniques, but with higher blood contamination with the WS. Diagnostic accuracy and tumor fraction did not differ between the compared techniques.
Conclusion: Overall, the WS technique in EUS-FNB allows a higher tissue core rate procurement compared with SP. Diagnostic accuracy and the rate of samples with adequate tumor fraction were similar between the two techniques.
Clinicaltrial.gov, number NCT04834193.