Optimal number of needle passes during EUS-guided fine-needle biopsy of solid pancreatic lesions with 22G ProCore needles and different suction techniques: A randomized controlled trial

Background and Objectives: The sensitivity of EUS-guided fine-needle biopsy (EUS-FNB) varies considerably. The optimal number of passes through a solid pancreatic lesion with a 22G FNB needle during EUS-FNB is controversial. This prospective randomized controlled study aimed to determine the optimal number of needle passes during EUS-FNB of solid pancreatic lesions, with 22G FNB needles and different sampling techniques. Methods: Pancreatic masses were sampled using 22G FNB needles with either the stylet slow-pull (SP) technique or the standard-suction (SS) technique. We determined the number of needle passes required to obtain a diagnostic accuracy of >90%. Differences between the two techniques in terms of technical success rate, cytological acquisition, core tissue acquisition, sensitivity, specificity, accuracy, positive predictive value, negative predictive value, and complications were analyzed. Results: A total of 120 patients were randomly assigned to either SP or SS group. Three patients who were lost to follow-up and one who did not complete 5 passes due to bent needle head were excluded from the study. Fifty-six cases in the SP group and 60 cases in the SS group were included in the analysis. For SP technique, the cumulative accuracy of passes 1, 2, 3, 4, and 5 was 44.83%, 76.79%, 87.50%, 92.86%, and 94.64%, respectively. For SS technique, the cumulative accuracy of passes 1, 2, 3, 4, and 5 was 71.67%, 85.0%, 90.0%, 93.33%, and 95.0%, respectively. For each group, there was no statistically significant difference in accuracy after 3 and 4 passes. After 4 passes, the pooled sensitivity (92.59% vs. 93.10%), accuracy (92.86% vs. 93.10%), and specificity (100% vs. 100%) were similar (P > 0.05) in the SP and SS groups, respectively. In addition, positive cytological diagnoses (83.9% vs. 85.0%) and positive histological diagnoses (71.4% vs. 78.3%) were comparable (P > 0.05) in the SP and SS groups, respectively. No statistically significant factor was found associated with diagnostic sensitivity for each group. Conclusion: When on-site cytological evaluation is unavailable, we recommend that at least 3 passes with 22G ProCore needles be performed during EUS-FNB using the SS technique, at least 4 passes when using SP technique. The SS technique showed potential advantages over SP technique in tissue acquisition and diagnostic capabilities.

Automated summary

This study aimed to determine the optimal number of needle passes during EUS-FNB of solid pancreatic lesions with 22G FNB needles, finding that when on-site cytological evaluation is unavailable, at least 3 passes using the SS technique are recommended, while at least 4 passes are recommended when using the SP technique. The SS technique showed potential advantages in tissue acquisition and diagnostic capabilities over the SP technique.