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A1745 - Tissue Adequacy of 25-Gauge Needle in Endobronchial Ultrasound: Is Bigger Truly Better?
Author Block: R. M. Davis1, P. Patel1, P. Whitten2; 1Pulmonary and Critical Care Fellowship, University of Illinois College of Medicine at Peoria, Peoria, IL, United States, 2University of Illinois College of Medicine at Peoria, Peoria, IL, United States.
Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has rapidly become the procedure of choice for tissue diagnosis of both benign and malignant mediastinal disease. This is largely due to the accuracy of tissue sampling with endobronchial ultrasound, which results in a high diagnostic yield at a much lower complication rate compared to invasive procedures. Anecdotally, it has been though that larger needles provide more tissue, and thus a better sample for diagnosis. Here we compared the sampling adequacy of a 25-gauge (G) needle with that of a 21-G needle. Ten lymph node biopsies were performed using EBUS-TBNA with both a 25-G and a 21-G needle. All biopsies were performed by the same attending physician, with the same number of passes. Initial slides were prepared from the first pass of each biopsy, with subsequent passes used to prepare a cell block. The pathology technician who was asked to assess adequacy of the slide and cell block was blinded to the needle used. In nine of ten biopsies, both the 25-G and 21-G provided adequate tissue for diagnosis. In the remaining biopsy, neither needle provided diagnostic tissue. All of the cell blocks provided adequate tissue for diagnosis. However, the 21-G samples did provide a larger amount of tissue. An adequate tissue sample can be obtained via EBUS-TBNA with a 25-G needle for tissue diagnosis. Although, the tissue sample was adequate with a 25-G needle, it did tend toward providing a smaller cell block. As biomarker testing becomes increasingly prevalent, larger amounts of tissue may be necessary for cytogenetic testing. While one of the purported benefits of the 25-G needle is increased scope flexibility with the needle deployed, there was difficulty using the needle with the scope acutely flexed. For some nodes, the EBUS had to be removed from the node, the needle advanced in to view, and then contact made with the wall for localization of the lymph node. This technical aspect of needle use, coupled with the fact that it may require more passes with the needle if a larger tissue sample is needed, could potentially increase case time. Longer case times result in additional anesthesia and risk for the patient. In addition, the 25-G needle does not create a needle track large enough to easily pass forceps for biopsy if desired. This has the potential to complicate diagnosis of non-malignant conditions that may require a larger tissue biopsy.