Radial Endobronchial Ultrasound-guided Transbronchial Cryobiopsy

Transbronchial lung cryobiopsy (TBLC) is a novel technique that has proved its diagnostic value in various diffuse parenchymal lung diseases (DPLD). However, there is substantial variability among interventional pulmonologists in procedural technique, diagnostic yield, and complication rate. Radial endobronchial ultrasound (R-EBUS) is useful for identification of ground-glass opacity lesions and can help identify target lung parenchyma. We aim to evaluate R-EBUS in TBLC histopathologic diagnosis for patients with DPLD.

This was a prospective observational study of patients with clinical and radiologic features suggestive of DPLD who underwent TBLC. The R-EBUS probe was initially advanced to the desired lobe under fluoroscopic guidance until reaching 1 cm from the pleura. R-EBUS images were identified looking for either blizzard or mixed blizzard signs. TBLC samples were sent to pathology and microbiology laboratories for diagnostic analysis. Procedural complications were recorded.

In total, 40 patients (16 women/24 men) with a mean age of 63 years were included. The mean area of the samples was 36.2 mm (9 to 189 mm) with mean number of samples per procedure of 3.45 (1 to 6). Definitive diagnosis was obtained in 37 patients (92.5%). The most frequent histopathologic patterns were: usual interstitial pneumonia (37.5%), nonspecific interstitial pneumonia (17.5%), and pulmonary infection (7.5%). There were 2 pneumothoraces (5%) and 5 cases of moderate bleeding (12.5%).

The use of R-EBUS to locate and select target lung biopsy site before TBLC might increase diagnostic yield. Randomized studies comparing TBLC histopathologic diagnosis with and without R-EBUS are needed to ascertain its clinical value.