Transbronchial cryobiopsy, updated guidelines for chronic cough in children, PD-1 inhibition
Interventional Chest/Diagnostic Procedures
Cryobiopsy for ILD: Careful stewardship needed
Interest in transbronchial cryobiopsy has accelerated rapidly in recent years. This procedure is performed by advancing a cryoprobe into the peripheral lung via flexible bronchoscopy, where lung tissue freezes and adheres to the probe and is subsequently extracted as a cryobiopsy. The number of cryobiopsy-related publications has increased exponentially since it was described in 2009 (Babiak A, et al. Respiration. 2009;78[2]:203). This interest stems from reports of high diagnostic yields in patients with interstitial lung disease (ILD) while maintaining complication rates similar to that of conventional bronchoscopic biopsy.
Traditional bronchoscopic biopsies are notoriously insensitive; a specific diagnosis can be established in fewer than a third of cases (Sheth JS, et al. Chest. 2017;151[2]:389). As such, surgical lung biopsy continues to be recommended but is associated with significant mortality (2%) and morbidity (30%) in patients with ILD (Hutchinson JP, et al. ARJCCM. 2016;193[10]:1161). Cryobiopsy, which appears to rival surgical lung biopsy in terms of ability to contribute to a specific diagnosis, is, therefore, a highly promising alternative (Tomassetti S, et al. AJRCCM. 2016;193[7]:745).
As cryobiopsy is increasingly adopted around the world, however, troubling reports of serious complications have surfaced. Most notable is the recently reported experience of the initial 25 cases performed at the University of Pennsylvania, in which almost one in four patients suffered serious complications (DiBardino DM, et al. Ann Am Thorac Soc. 2017;14[6]:851). The authors pointed to lack of a predefined procedural protocol, as well as several choices relating to the specific technique used, including inconsistent use of fluoroscopy, lack of prophylactic bronchial blocker placement, and predominant use of laryngeal mask airways as potential contributing factors. Indeed, many variations of the basic cryobiopsy procedure have been described (Lentz RJ, et al. J Thoracic Dis. 2017;9[7]:2186), with no formal guidance or training available to inform advanced bronchoscopists interested in this procedure.
It is incumbent on the interventional pulmonology and ILD specialist communities to be responsible stewards of this promising procedure. Implementation of three parallel efforts to standardize and rigorously study this procedure should be considered as soon as possible: creation of expert consensus guidelines establishing best-practices for safe and effective biopsy technique; a training requirement before independent performance of the procedure; and creation of an international cryobiopsy registry to facilitate higher-quality research into optimal technique and outcomes. We owe this to our patients.
Robert J. Lentz, MD
NetWork Member
Fabien Maldonado, MD, FCCP
NetWork Member
