TUS-EPIC: Thoracic Ultrasonography for Exclusion of Iatrogenic Pneumothorax in Post Transbronchial Lung Cryobiopsy – a Safe Alternative to Chest X-ray

Background: The incidence of iatrogenic pneumothorax (IPTX) following transbronchial lung cryobiopsy (TBLCB) ranges from 1.4% to 20.2%. While chest X-ray (CXR) is the standard imaging modality to exclude IPTX, thoracic ultrasound (TUS) has demonstrated superior accuracy in de-tecting pneumothorax across various contexts. This study evaluates TUS as a reliable alternative to routine CXR for ruling out IPTX after TBLCB. Methods: A retrospective observational study included 51 patients undergoing ambulatory TBLCB. Pre- and post-TBLCB TUS were performed. CXR was reserved for cases where TUS findings were inconclusive (absence of sliding lung [SL] and seashore sign [SS] in all lung zones) or if pa-tients exhibited symptoms or signs of IPTX. Results: TUS findings were concordant in 44 (86.1%) patients, of whom 42 (95.5%) did not require CXR. Two patients (4.5%) with symptomatic IPTX were identified and managed. Among the seven patients (13.7%) requiring CXR due to inconclusive TUS or symptoms, five (71.4%) were negative for IPTX, and two (28.6%) had asymptomatic IPTX. Conclusion: Our TUS protocol effectively ruled out clinically significant IPTX, eliminating routine CXR in 95.5% of patients. TUS is a safe alternative to CXR post-TBLCB, with CXR reserved for inconclusive TUS findings or symptomatic cases.