[Endobronchial sonography in the diagnosis of pulmonary and mediastinal tumors].

Endobronchial sonography was performed during bronchoscopy in 58 patients (48 males and 10 females; mean age 59 [29-76] years) with confirmed pulmonary or mediastinal tumour using a 6.2 or 9 F ultrasound catheter. The procedure was successfully performed in 50 patients from the trachea down to the smallest bronchi (of 2 mm diameter). Tumour tissue was not visualized in five patients with small peripheral carcinomas. In three patients the catheter probe could not be passed through the tumour region. The method provided a three-dimensional image of the bronchial wall, corresponding to the histological tissue layers of mucosa, cartilage and adventitia. Pulmonary arteries were identified by the echo-free lumen and pulsatile oscillations in calibre. Tumours and lymph-nodes were echo-poor and could thus be distinguished from the echo-rich bronchial wall. Several consequences arose from these findings: laser treatment was not proceeded with in two cases, because a fairly large pulmonary artery lay near the stenosis; in three cases malignant tumours were recognized to lie either entirely intramurally or peribronchially, which had not been seen on bronchoscopy alone. It is concluded from these preliminary observations that endobronchial sonography is a highly promising addition to conventional bronchoscopy.