Confirming Whether Fine Needle Biopsy Device Shortens the Learning Curve of Endoscopic Ultrasound-Guided Tissue Acquisition without Rapid Onsite Evaluation

Background/Aims: Endoscopic ultrasonography (EUS)-guided tissue acquisition requires a long learning curve. We aimed to compare the skill maturation curves between fine needle aspiration (FNA) and biopsy (FNB) for tissue acquisition. Methods: The initial 60 procedures performed by the trainee endosonographer (30 FNA vs. 30 FNB) were consecutively enrolled. The difference in procedure performance was compared between the two groups. Learning curves were assessed. Twenty additional cases were subsequently enrolled to assess the consistency of performance in the FNB group. Results: The FNB group acquired larger tissue samples (2.35 vs. 0.70 mm²; p<0.001) with lower blood content (p=0.001) and higher tissue quality (p=0.017) compared with the FNA group. In addition, the FNB group required less needle pass to establish a diagnosis (2.43 vs. 2.97; p=0.006). A threshold diagnostic sensitivity of ≥80% was achieved after performing 10 FNB procedures. The number of needle passes significantly decreased after conducting 20 FNB procedures (1.80 vs. 2.70; p=0.041). The diagnostic sensitivity and number of needle passes remained the same in the subsequent FNB procedures. By contrast, this skill maturation phenomenon was not observed after performing 30 FNA procedures. Conclusions: In EUS-guided tissue acquisition, the FNB needle was more efficient and thus shortened the learning curve of EUS-guided tissue acquisition in trainee endosonographers.