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Clinical evaluation of the utility of a flexible 19-gauge EBUS-TBNA needle.

Background
Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is an established modality for the assessment of mediastinal and hilar adenopathy. To overcome the sampling limitations of standard 21- and 22-gauge EBUS-TBNA needles, a new flexible 19-gauge (Flex 19G) needle was developed.


Methods
We performed a retrospective analysis of patients who underwent EBUS-TBNA sampling with the Flex 19G needle. A 22G needle was always used first for cytology, followed by a Flex 19G needle, either an early version (Oct/2014-Sep/2015) or a final version needle (May/2016-Jan/2017), for tissue sampling. The success rate of obtaining samples, specimen quantity, and safety were evaluated and compared.


Results
All sampling procedures in 45 patients and 82 targets were performed without complication and the overall diagnostic yield from cytology was 100%. Furthermore, 28% of Flex 19G samples were sufficient for histopathological diagnosis. Yield improved with an increased number of passes and if the target was larger. Compared to the early version evaluated in 52 targets, the final version of the Flex 19G needle evaluated in 30 targets provided significantly larger volume samples and more frequent diagnostic cores. Tissue obtained with the Flex 19G needle retained cohesiveness to a larger degree and was of higher cellularity compared to cytological samples processed as cell blocks.


Conclusions
The Flex 19G is safe and provides larger volumetric and cohesive tissue samples that are appropriate for histopathological processing. The final version of the Flex 19G could be a good choice in selected cases where greater tissue acquisition is required.