INTRODUCTION: Transbronchial needle aspiration (TBNA) is an established technique for the diagnosis and staging of malignancy in the mediastinum and hilum. Recently a bronchoscope was developed that integrated a curvilinear array endobronchial ultrasound (EBUS) with TBNA. This has been reported to increase the diagnostic yield(1). The EBUS TBNA needle is cumbersome and requires complete removal of the guidewire before applying suction. We describe 2 patients with a suspicion for malignancy in which different techniques of EBUS-TBNA were performed in order to maximize our specimen yield.
CASE PRESENTATION: Both patients underwent EBUS-TBNA using an EBUS bronchoscope (Olympus BF-UC180F with a 2.2 mm working channel) and the Olympus Vizishot needle (model number NA-201SX-4022). Three aspirations were performed. On the first EBUS-TBNA the guidewire was partially withdrawn 5 cm after insertion of the needle into the lesion. The needle was then moved back and forth within the lesion without suction to obtain specimen. The specimen was placed on a slide by pushing in the guidewire. On the second aspiration the guidewire was removed after insertion and suction was applied before moving the needle back and forth. The third TBNA was without guidewire but with suction during needle movement. All specimens were smeared on a glass slide and fixed with 90% ethanol or sent for cell block if it was a bloody aspirate. Before the three aspirations with the Vizishot needle a standard histology needle (MW-319) was used with the EBUS bronchoscope. On one of the patients all four aspirations were positive for adenocarcinoma. The cytology specimen with partial guidewire removal was of better quantity and quality of tumor cells with less blood than the second aspiration. The second patient only had malignant cells present on the first aspiration consistent with squamous cell carcinoma. The histology obtained from the MW319 needle was also diagnostic. Cell block from the second aspiration with the Vizishot needle was negative.
DISCUSSIONS: Malignancy was diagnosed in all aspirations using the Vizishot needle in the first patient but the second and third aspirations were nondiagnostic in the second patient. The MW-319 needle has an inner needle that functions as a trocar to prevent plugging and is connected to an inner guidewire that need not be fully retracted after puncture for suction. This needle was successfully used for EBUS-TBNA tissue core biopsies for histological analysis in both patients.
CONCLUSION: These cases suggest complete guidewire removal is not necessary with the Vizishot needle and may expose the patient to additional risk. A concern exists of an increased risk of mediastinitis if the guidewire is used to unplug a needle after it has entered a lesion. We use it to push the specimen onto the glass slide for cytological examination. Our past experience with different techniques of standard TBNA and percutaneous needle aspiration is that the back and forth movement within the lesion rather than the application of suction is the most important factor for obtaining good quality specimens(2). We believe that the ability to use a histology needle with EBUS-TBNA will enhance the diagnostic yield of this technique through the incorporation of molecular marker analysis. Formal studies are needed to validate these techniques with EBUS-TBNA.
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