Endoscopic Ultrasound-Guided Fine-Needle Biopsy for Tissue Sampling of Biliary Strictures: A Multicenter Prospective...

There is a lack of data concerning the diagnostic yield of endoscopic ultrasound (EUS)-guided fine-needle biopsy (FNB) with end-cutting needles for tissue sampling of biliary strictures. We aimed to assess the efficacy of FNB needles in this setting.

Prospective study involving four international centers. The primary outcome was sample adequacy. Secondary outcomes were diagnostic accuracy, quality of the sample, sensitivity, specificity, and adverse event rate.

Forty-five patients were enrolled (30 with distal strictures and 15 with peri-hilar strictures), with a mean stricture size of 19.4 ± 6.1 mm. Sample adequacy was 93.3% (81.7%-98.6%) in the whole cohort, with 96.6% (82.7%-99.9%) and 86.6% (59.5%-98.3%) adequacy rates in distal and peri-hilar strictures, respectively (p = 0.25). After one needle pass, adequacy was 62.2% (46.5%-76.2%, 73.3%, 54.1%-87.7% in distal and 40%, 16.3%-67.7% in peri-hilar strictures, p = 0.04), while after two passes, it was 84.4% (70.5%-93.5%, 96.6%, 82.7%-99.9% in distal and 60%, 32.2%-83.6% in peri-hilar strictures, p = 0.03). Diagnostic accuracy was 91.1% (78.7%-97.5%) in the whole cohort, 96.6% (82.7%-99.9%) in patients with distal strictures and 80% (51.9%-95.6%) in patients with peri-hilar ones (p = 0.10). Diagnostic sensitivity was 89.7% (75.7%-97.1%, 96.4%, 82.7%-99.9% in distal strictures and 75%, 42.8%-94.5% in peri-hilar ones, p = 0.03). Only 2 cases (4.4%, 0.5%-15.5%) of minor bleeding were observed in the whole cohort, one in each subgroup (p = 1.0).

End-cutting FNB needles provide high adequacy and accuracy rates in patients with biliary strictures without an associated pancreatic or abdominal mass and could play an important role in the diagnostic algorithm of these lesions.