Evaluation of 19-gauge vs 21-gauge EBUS TBNA in Assessing Thoracic Lymphadenopathy

Endobronchial ultrasound-guided transbronchial needle aspirate (EBUS-TBNA) is a technique used to take samples of body tissue inside the chest without having to undergo an operation. During this procedure, a special telescope (called a bronchoscope) is inserted through the mouth into the airways. Ultrasound technology allows the doctor to see the structures just outside the airway. By being able to see the structures outside the airway, the doctor is able to safely pass a fine needle through the airway to take samples of abnormal tissue. EBUS-TBNA is used to take samples of tissue from the mediastinum. The mediastinum is the part of the chest between the lungs, and contains the heart, gullet, windpipe and lymph nodes. This area of the body is usually difficult to access without open surgery, hence the use of EBUS-TBNA. EBUS-TBNA may be used to investigate enlarged lymph nodes. This may be due to tuberculosis, sarcoidosis or cancer. Currently, smaller 21-gauge and larger 19-gauge needles are used during the EBUS-TBNA procedure at Regions Hospital. The purpose of this study is to find out which needle is better in finding the explanation for the enlarged lymph nodes, and any follow up procedures that may be necessary if the investigators are unable to get enough tissue during the EBUS-TBNA procedure (surgical sampling, radiological sampling, and/or follow-up imaging).

All patients will be allocated to the same arm. All patients will have EBUS TBNA done with both 19-gauge and 21-gauge needles during the procedure.

Diagnostic yield refers to the proportion of tissue samples collected by each needle (19 gauge vs 21 gauge) that were of sufficient quantity and quality to yield (i.e. produce) an accurate diagnosis for the patient's enlarged lymph nodes. Characterization of diagnostic category (true positive, true negative, false negative, false positive) were made by comparing the patient's presumed diagnosis/initial indication for presentation in comparison to their final diagnosis as determined by a combination of pathological findings of EBUS-TBNA, follow up imaging, surgical sampling, or clinical follow up. The diagnostic yield of each needles was reported as a ratio of true positives and true negatives added together, divided by the total number of lymph nodes sampled (141). Diagnostic yield of 19-gauge needle: 89.4% Diagnostic yield of 21-gauge needled: 88.7%

Diagnostic yield refers to the proportion of tissue samples collected by each needle (19 gauge vs 21 gauge) that were of sufficient quantity and quality to yield (i.e. produce) an accurate diagnosis for the patient's enlarged lymph nodes. Characterization of diagnostic category (true positive, true negative, false negative, false positive) were made by comparing the patient's presumed diagnosis/initial indication for presentation in comparison to their final diagnosis as determined by a combination of pathological findings of EBUS-TBNA, follow up imaging, surgical sampling, or clinical follow up. The diagnostic yield of each needles was reported as a ratio of true positives and true negatives added together, divided by the total number of lymph nodes sampled (141).

Inclusion Criteria: Age 18 years or older Able to provide informed consent Referred for EBUS TBNA sampling at Regions Hospital Exclusion Criteria: On therapeutic warfarin, Plavix, or ticagrelor in the past 5 days INR>1.8 or platelets <50K