Transbronchial Lung Cryobiopsy in Interstitial Lung Diseases: Best Practice

Abstract

The lung biopsy in interstitial lung disease (ILD) represents an important diagnostic step when the clinical and radiological data are insufficient for a firm diagnosis. A growing body of evidence suggests the utility of transbronchial lung cryobiopsy (TBLC) in the diagnostic algorithm of ILD as it allows, compared to transbronchial lung biopsy with conventional forceps, a better identification of complex histological patterns - such as usual interstitial pneumonia - and can provide information which has a clinical impact on the multidisciplinary discussion similar to that provided by surgical lung biopsy. Performed correctly, it appears to have a better safety profile than surgery. The decision to perform a lung biopsy should be a multidisciplinary decision process where it is felt that there is sufficient diagnostic doubt after a careful clinical evaluation including review of the computed tomograms of the thorax. The presence of severe pulmonary hypertension (> 50 mm Hg), poor lung function (FVC < 50%), or dismissed gas transfer (DLCO of < 35%) are considered relative contraindications for TBLC. Anticoagulants and antiplatelet drugs should be discontinued for the minimum period required for the specific drugs. The greatest consideration should be given to ensure the biopsy is performed safely and we recommend the use of either an endotracheal tube or rigid bronchoscopy. Deep sedation or general anesthesia allow better control of the procedure and a better patient experience. Prophylactic balloon blockers should be used to tamponade any bleeding and also to prevent overspill of blood from the segment that is being sampled. The procedure should be performed under fluoroscopy to ensure that samples are ideally obtained about 10 mm from the pleural edge. The cryoprobe is activated for about 5 s for the first biopsy and then adjusted according to the sample size obtained. With a careful standardized approach it is possible to obtain good-quality lung specimens for diagnosis in a safe manner.

Keywords: Bronchoscopy; Diffuse lung disease; Idiopathic pulmonary fibrosis; Interstitial lung disease; Transbronchial lung cryobiopsy.