Diagnostic performance and safety of endobronchial ultrasound-guided transbronchial cryobiopsies in the diagnosis of mediastinal lesions.

Background: Endobronchial ultrasound-guided transbronchial cryobiopsy (Cryo-EBUS) is an emerging technique for diagnosing mediastinal lesions, offering larger and better-preserved tissue samples compared to endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). However, its diagnostic performance, safety, and role in clinical practice remain under investigation.

Methods: We conducted a prospective observational study including 100 consecutive patients with mediastinal/hilar lymphadenopathies or masses who underwent both Cryo-EBUS and EBUS-TBNA in the same procedure. The diagnostic yields, their ability to provide adequate tissue for molecular testing, safety outcomes, and the learning curve were analyzed.

Results: Cryo-EBUS demonstrated a significantly higher diagnostic yield (80 %, 95 %CI:72-88 %) compared to EBUS-TBNA (72 %, 95 %CI:63-81 %), with a further increase when both techniques were combined, especially in cancer lesions (93.3 %, 95 %CI:87.6-99.1 %). The technique was particularly effective in PET-CT positive lesions. Additionally, Cryo-EBUS provided high-quality tissue samples, allowing biomarker analysis in 91 % of cases. A learning curve effect was observed, with diagnostic yield improving from 53 % in the first 15 cases to 84.7 % thereafter (p = 0.001). Cryo-EBUS had a favorable safety profile, with only three minor complications (pneumothorax and pneumomediastinum), all conservatively resolved.

Conclusion: Cryo-EBUS is a safe and effective technique for mediastinal lesion diagnosis, particularly when combined with EBUS-TBNA. It enhances diagnostic accuracy, improves molecular testing capabilities, and remains minimally invasive. The integration of PET findings may further optimize its application. Standardized protocols are needed to refine its clinical use and establish its role in routine practice.