THE FIRST EXPERIENCE IN USING ELASTOGRAPHY IN COMBINATION WITH ENDOBRONCHIAL ULTRASONOGRAPHY FOR MEDIASTINAL PATHOLOGY: PRELIMINARY ASSESSMENT OF FEASIBILITY AND COMPARISON OF CHARACTERISTICS VIA DIFFERENT APPROACHES

Objective: to preliminarily assess the feasibility of elastography in endobronchial ultrasonography and to compare characteristics via different accesses.

Material and methods. The investigation enrolled 3 patients (malignant, benign mediastinal adenopathy, paratracheal tumor). Elastography was carried out using a Pentax EB-1970UK echobronchoscope with a Hitachi Noblus ultrasound scanner. All the patients underwent fine-needle aspiration biopsy of mediastinal and pulmonary lymph nodes/masses with 22G needles (Cook, Medi-Globe). Sequential study of the same group of lymph nodes through diffe￾rent approaches through the esophagus and trachea was conducted, and its characteristics were compared in one patient.

Results. A total of 8 lymph nodes and one paratracheal mass (Group 4L-7-4R-2R) were assessed in three patients. Reproducible images acceptable for visual assessment were obtained in all cases. The wall of the trachea and bronchi had no significant negative impact on the quality of an obtained image. Both malignant lesion of lymph nodes and paratracheal mass was accompanied by decreased tissue elasticity in the area of interest. Assessment of the same benign lymph node through different approaches revealed a clear discordance between elastographic findings with a drastic decrease in elasticity values via an endobronchial approach.

Conclusion. Endobronchial ultrasonography elastography is technically feasible. The wall of the trachea and bronchi has no significant impact on the quality of an obtained image; elastographic data are reproducible during re-measurements. Comparison of elastographic characteristics through different approaches suggests that there is a tendency to overestimate data on lymph node density during endobronchial examination versus a transesophageal approach. Thus, the direct transfer of the accumulated data and patterns of elastographic diagnosis to an endobronchial approach is impossible and likely to require a revision of criteria to estimate malignancy-associated changes during its application.

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