ENDOBRONCHIAL ULTRASOUND-GUIDED NEEDLE ASPIRATION OF MEDIASTINAL ADENOPATHY

We conducted a randomized, controlled trial to prospectively confirm t hat ultrasound-directed transbronchial needle aspiration (USTBNA) resu lts in: (1) improved sensitivity for detecting lymph nodes involved wi th neoplasm, and (2) a decreased number of aspirates needed to achieve a diagnosis as compared with standard transbronchial needle aspiratio n (TBNA). The study was conducted in a tertiary medical center on pati ents undergoing fiberoptic bronchoscopy in the evaluation of enlarged mediastinal lymph nodes. USTBNA or TBNA were followed by rapid, on-sit e cytopathology examination of the collected specimens. Measurements i ncluded the (1) age and sex of the patient, prior diagnosis of cancer, nodal short-axis diameter and node location as determined by computer ized tomography (CT), and endobronchial abnormalities at bronchoscopy; (2) number, order, and location of transbronchial aspirates and resul ts of on-site evaluation; (3) results of surgical exploration in patie nts with negative transbronchial needle aspiration; (4) sensitivity, s pecificity, and diagnostic accuracy of USTBNA and TBNA; (5) number of aspirates required for successful lymph node aspiration as well as for a diagnosis of cancer for both USTBNA and TBNA; and (6) multiple logi stic regression analysis to determine the significance of combinations of clinical predictors and needle-aspirate results. Eighty-two bronch oscopic examinations were performed on 80 patients. We found no signif icant difference between USTBNA and TBNA in sensitivity (82.6% versus 90.5%, respectively), specificity (100% for both), or diagnostic accur acy (86.7% versus 91.7%, respectively). The sensitivity, specificity, and diagnostic accuracy of USTBNA and TBNA were similarly high, regard less of node location (paratracheal or subcarinal). A decrease in the number of aspirates required for lymph node sampling approached statis tical significance for all USTBNAs as compared with TBNAs (2.03 +/- 0. 19 versus 2.62 +/- 0.25, p = 0.06), but this was not demonstrated for the number required to confirm cancer (1.95 +/- 0.47 versus 2.68 +/- 0 .21, p = 0.17). The number of aspirates to successful lymph node aspir ation decreased with USTBNA versus TBNA in paratracheal lymph nodes (2 .00 +/- 0.20 versus 2.91 +/- 0.34, p = 0.03), but not to a diagnosis o f cancer (1.93 +/- 0.25 versus 3.00 +/- 0.58, p = 0.11). No difference was seen in the number of aspirates for subcarinal nodes. The number of TBNA attempts for paratracheal lymph node sampling was inversely co rrelated with node size (r = 0.48, p = 0.02). No such relation was see n with USTBNA of paratracheal nodes (r = 0.09, p = 0.66), TBNA of subc arinal nodes, or USTBNA of subcarinal nodes. A similar relation was se en between the number of aspirates to a diagnosis of cancer. On multip le logistic regression analysis, a positive transbronchial aspirate wa s associated only with a larger lymph node and history of prior cancer . We conclude that: (1) in the setting of on-site cytopathology, trans bronchial needle aspiration has a high sensitivity, specificity, and d iagnostic accuracy in the evaluation of enlarged mediastinal lymph nod es suspected of harboring malignancy; (2) mediastinal anatomy, includi ng vascular structures and lymph nodes, is clearly imaged with endobro nchial ultrasonagraphy; (3) a greater short-axis diameter of the media stinal lymph node and history of a prior malignancy increase the likel ihood of a positive transbronchial aspiration; (4) USTBNA exhibits a s imilarly high diagnostic yield to TBNA in the setting of rapid on-site cytopathology evaluation; (5) USTBNA decreases the number of aspirate s required for paratracheal lymph node sampling, which may be particul arly useful in sampling smaller paratracheal nodes or at institutions that do not utilize rapid on-site cytopathology evaluation.