A Comparison of Specimen Size and Diagnostic Performance of 19G vs 22G EBUS-TBNA Needles: A Preclinical Study

Abstract

SESSION TITLE: Interventional Pulmonary Procedures SESSION TYPE: Original Investigation Slide PRESENTED ON: Wednesday, November 1, 2017 at 02:45 PM - 04:15 PM PURPOSE: The 21G and 22G EBUS-TBNA needles are limited in the amount of tissue that they can provide for extended molecular and histopathological analysis. Recently, a new 19G ViziShot FLEX needle (Olympus Respiratory America, Redmond, WA) became available, but to date comparative data has been limited. We compared the specimen size and diagnostic performance of the new 19G needle to that of the ViziShot 22G (Olympus, Tokyo, Japan) needle in a swine model of granulomatous lymphadenopathy. METHODS: The mediastinal lymph nodes of 10 domestic swine were measured prior to the injection of a talc slurry that, over time, induced granulomatous inflammation. After maturation, affected LNs were re-measured and sampled with the 19G and 22G needles by three clinicians experienced in EBUS-TBNA using a standardized sampling technique. Each sample was weighed and photographed prior to histopathological processing. The study animals were subsequently euthanized and the LNs were preserved. Tissue core area was determined by quantifying sample area using image analysis software (ImageJ, NIH, Bethesda, MD). Volume was estimated using sample area and known needle measurements. A pathologist, blinded to the type of needle used, provided a numerical Biopsy Core Morphology Grade (BCMG) assessing sample quality and a Biopsy Diagnostic Correlation Grade (BDCG) comparing the needle samples to the corresponding LN specimens. RESULTS: A total of 132 paired samples were collected from 38 LNs (2R, 4R, 4L and 7). There was a significant increase in the average LN size from a baseline of 11.6±3.2 to 15.2±3.8mm; p<0.001. The average mass of the TBNA samples collected by the 19G was higher than that of samples collected by the 22G needle, 33.78±47.48 vs. 25.18±32.08 mg, (p <0.002). The calculated core tissue volume collected by the 19G was higher than that of the samples collected by the 22G needle, 11.40±13.91 vs. 6.91±6.42 mm3, (p <0.0004). The pooled needle biopsy samples for the 19G and the 22G needles had similar BCMG (19G 1.38±0.86 vs 22G 1.43±0.87, p>0.2) and BDCG grades (19G 1.54±0.93 vs 22G 1.57±0.93, p>0.2). The samples collected by the 19G needle demonstrated a trend towards more frequent identification of granuloma (46% vs. 32% of specimens, p=0.06) but also contained more cartilage (4.81±16.49% vs. 0.49±1.46%, p<0.003). There was a tendency for the 22G needle to collect more blood (p=0.057). No procedure-related complicatons were detected. CONCLUSIONS: In the hands of experienced clinicians, the 19G and the 22G EBUS-TBNA needles had similar diagnostic yields in the swine model of granulomatous lymphadenopathy. However, the samples collected by the 19G were larger with potentially less blood contamination and a trend towards a higher detection rate of granulomatous inflammation than the samples collected by the 22G needle. CLINICAL IMPLICATIONS: Larger diameter needles may be advantageous for EBUS-TBNA, provided they do not increase procedural risk and/or blood contamination of the sample. DISCLOSURE: Kasia Czarnecka-Kujwa: Consultant fee, speaker bureau, advisory committee, etc.: I have received a consulting honorarium from the Olympus America Anna Sczaniecka: Employee: Employee of Spiration d/b/a Olympus Respiratory America Sujeeth Parthiban: Employee: Employee of Spiration d/b/a Olympus Respiratory America David Dillard: Employee: Employee of Spiration d/b/a Olympus Respiratory America Xavier Gonzalez: Employee: Spiration d/b/a Olympus Respiratory America Alain Tremblay: Consultant fee, speaker bureau, advisory committee, etc.: Received a consulting honorarium from Spiration d/b/a Olympus Respiratory America Kazuhiro Yasufuku: Consultant fee, speaker bureau, advisory committee, etc.: Received a consulting honorarium from Spiration d/b/a Olympus Respiratory America No Product/Research Disclosure Information