Transbronchial Lung Cryobiopsy in Patients with Interstitial Lung Disease: A Systematic Review

In 2018, a systematic review evaluating transbronchial lung cryobiopsy (TBLC) in patients with interstitial lung disease (ILD) was performed to inform American Thoracic Society, European Respiratory Society, Japanese Respiratory Society, and Asociación Latinoamericana del Tórax clinical practice guidelines on the diagnosis of idiopathic pulmonary fibrosis. To perform a new systematic review to inform updated guidelines. Medline, Excerpta Medica Database, and the Cochrane Central Register of Controlled Trials (CCTR) were searched through June 2020. Studies that enrolled patients with ILD and reported the diagnostic yield or complication rates of TBLC were selected for inclusion. Data was extracted and then pooled across studies via meta-analysis. The quality of the evidence was appraised using the grading of recommendations, assessment, development, and evaluation approach. Histopathologic diagnostic yield (number of procedures that yielded a histopathologic diagnosis divided by the total number of procedures performed) of TBLC was 80% (95% confidence interval [CI], 76-83%) in patients with ILD. TBLC was complicated by bleeding and pneumothorax in 30% (95% CI, 20-41%) and 8% (95% CI, 6-11%) of patients, respectively. Procedure-related mortality, severe bleeding, prolonged air leak, acute exacerbation, respiratory failure, and respiratory infection were rare. The quality of the evidence was very low owing to the uncontrolled study designs, lack of consecutive enrollment, and inconsistent results. Very low-quality evidence indicated that TBLC has a diagnostic yield of approximately 80% in patients with ILD, with manageable complications.