Evaluation of histological specimens obtained by two types of EBUS-TBNA needles: a comparative study

Comparison of the harvest volume between maneuvers of endobronchial ultrasound-guided transbronchial needle aspiration including the "cross-fanning technique"

Recently, a certain volume of biopsy specimens has been required for genetic testing of tumors using endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). This study aimed to verify the superiority of our newly devised EBUS-TBNA biopsy technique, the "cross-fanning technique," which combines rotation and up-down maneuvers, by comparing its harvest volume with that of other maneuvers. Using a bronchoscope simulator, ultrasonic bronchoscope, and 21-gauge puncture needle, we compared the weight of silicone biopsy specimens obtained by the following 4 procedures: Conventional maneuver; Up-down maneuver; Rotation maneuver, and; Cross-fanning technique. Each procedure was repeated 24 times in total, rotating the sequences of the maneuvers, and the operator/assistant pair to align the conditions. The means ± standard deviations of the sample volumes for each puncture technique were as follows: 2.8 ± 1.2 mg; 3.1 ± 1.6 mg; 3.7 ± 1.2 mg, and; 3.9 ± 1.2 mg. There was a significant difference between the 4 groups (P = .024). The post hoc test showed a statistically significant difference between techniques A and D (P = .019). This study showed that the cross-fanning technique might contribute to the increased volume of tissue samples obtained by EBUS-TBNA biopsy.

The Impact of Core Tissues on Successful Next-Generation Sequencing Analysis of Specimens Obtained through Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration

The success rate of next-generation sequencing (NGS) with specimens obtained through endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) among patients with lung cancer as well as the related clinical factors remain unclear. We aimed to determine the optimal number of punctures and core tissues during EBUS-TBNA for NGS in patients with non-small-cell lung cancer (NSCLC) as well as the association of chest computed tomography (CT) and EBUS findings with successful NGS. We retrospectively reviewed 156 consecutive patients with NSCLC who underwent EBUS-TBNA for NGS (Oncomine^TM Dx Target Test). Using the receiver operating characteristic curve, we calculated the optimal numbers of punctures and core tissues for NGS and evaluated CT and EBUS findings suggestive of necrosis and vascular pattern within the lesion. The success rate of NGS was 83.3%. The cut-off value for the number of core tissues was 4, and the sensitivity and specificity of successful NGS were 73.8% and 61.5%, respectively. Logistic regression analysis revealed that the number of core tissues (≥4) was the sole predictor of successful NGS. CT and EBUS findings were not associated with successful NGS. Bronchoscopists should obtain sufficient core tissues for successful NGS using EBUS-TBNA specimens.