Repeated EUS-fine needle biopsy of solid pancreatic lesions after previous non-diagnostic or inconclusive sampling

Objectives: Repeated EUS-guided tissue acquisition represents the standard practice for solid pancreatic lesions after previous non-diagnostic or inconclusive results. Since data are lacking, we aimed to evaluate the diagnostic performance of repeated EUS-fine needle biopsy (rEUS-FNB) in this setting. Primary outcome was diagnostic accuracy; sample adequacy, sensitivity, specificity, and safety were secondary outcomes. Methods: Consecutive patients undergoing rEUS-FNB for solid pancreatic lesions at 23 Italian centers from 2019-2021 were retrieved. Pathology on surgical specimen, malignant histology together with ≥6-month follow-up, and benign pathology together with ≥12-month follow-up were adopted as gold standards. Results: Among 462 patients, 56.5% were male, with a median age of 68 [59-75] years, malignancy prevalence 77.0%. Tumor size was 26 [20-35] mm. Second-generation FNB needles were used in 89.6% cases. Diagnostic accuracy, sensitivity, and specificity of rEUS-FNB were 89.2%, 91.4% and 81.7%, respectively (19 false negative and 12 false positive results). On multivariate analysis, rEUS-FNB performed at high-volume centers (OR 2.12, 95% CI, 1.10 - 3.17, P=0.03) and tumor size (OR 1.03, 95% CI 1.00 - 1.06, P=0.05) were independently related to diagnostic accuracy. Sample adequacy was 94.2%. Use of second-generation FNB needles (OR 5.42, 95% CI 2.30 - 12.77, P<0.001) and tumor size >23 mm (OR 3.04, 95% CI 1.31 - 7.06, P=0.009) were independently related to sample adequacy. Conclusions: Repeated EUS-FNB allowed optimal diagnostic performance after non-diagnostic or inconclusive results. Patients' referral to high-volume centers improved diagnostic accuracy. The use of second-generation FNB needles significantly improved sample adequacy over standard EUS-FNB needles. Clinicaltrial: gov registration NCT05226572.