Melanie Scarlett Mangold

Background: Limited data exist on the reliability, efficacy and safety of ultrasound-guided transbronchial cryobiopsy for suspicious mediastinal and hilar lesions. This study shares findings from implementing this method and compares the results with those of the standard endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). Methods: Patients undergoing diagnostic bronchoscopy for mediastinal or hilar lesions in four Swiss centres were included. The study aims to assess the diagnostic yield and safety of EBUS-guided cryobiopsy compared with EBUS-TBNA. Tunnelling to the target lesion was performed using an electric needle knife (70.8%), a 19 G- (12.4%) or a 22 G needle (16.8%). Cryobiopsies were obtained with a freezing time of 4–7 s (18.2% with a 1.7 mm probe) or 6–10 s (81.8% with a 1.1 mm probe). Results: Altogether, 137 patients were enrolled with a median follow-up of 89 days. The overall diagnostic yield was 56.2% for EBUS-TBNA and 91.2% for cryobiopsies (p<0.001). Cryobiopsies increased the diagnostic yield for benign disorders (+28.5%), uncommon tumours (+5.9%) and other metastatic cancer (+0.6%), but not for lung cancer (+0%). For lung cancer (n=27), immunohistochemistry was obtainable in 40.7% of EBUS-TBNA (median of 3 probes [IQR 3 to 3]), significantly lower than cryobiopsy’s 88.9% yield (median of 4 probes [IQR 3 to 5]) (p<0.001). Adverse events were found in 23.4% of participants; 10.2% had mild to moderate bleeding, 0.7% had pneumonia, and 0.7% (one) of patients had pneumothorax following pneumomediastinum. No deaths or mediastinum infections were observed. Conclusion: Cryobiopsy of mediastinal and hilar lesions improves the diagnostic yield compared with EBUS-TBNA while maintaining a favourable safety profile.

A chest X-ray (CXR) is recommended after bronchoscopies with an increased risk of pneumothorax (PTX). However, concerns regarding radiation exposure, expenses and staff requirements exist. A lung ultrasound (LUS) is a promising alternative for the detection of PTX, though data are scarce. This study aims to investigate the diagnostic yield of LUS compared to CXR, to exclude PTX after bronchoscopies with increased risk. This retrospective single-centre study included transbronchial forceps biopsies, transbronchial lung cryobiopsies and endobronchial valve treatments. Post-interventional PTX screening consisted of immediate LUS and CXR within two hours. In total, 271 patients were included. Early PTX incidence was 3.3%. Sensitivity, specificity, and the positive and negative predictive values of LUS were 67.7% (95% CI 29.93–92.51%), 99.2% (95% CI 97.27–99.91%), 75.0% (95% CI 41.16–92.79%) and 98.9% (95% CI 97.18–99.54%), respectively. PTX detection by LUS enabled the immediate placement of two pleural drains along with the bronchoscopy. With CXR, three false-positives and one false-negative were observed; the latter evolved into a tension-PTX. LUS correctly diagnosed these cases. Despite low sensitivity, LUS enables early diagnosis of PTX, thus preventing treatment delays. We recommend immediate LUS, in addition to LUS or CXR after two to four hours and monitoring for signs and symptoms. Prospective studies with higher sample sizes are needed.