Transbronchial Lung Cryobiopsy and Video-assisted Thoracoscopic Lung Biopsy in the Diagnosis of Diffuse Parenchymal Lung Disease A Meta-analysis of Diagnostic Test Accuracy

Rationale: Transbronchial lung cryobiopsy is increasingly being used for the assessment of diffuse parenchymal lung diseases. Several studies have shown larger biopsy samples and higher yields compared with conventional transbronchial biopsies. However, the higher risk of bleeding and other complications has raised concerns for widespread use of this modality. Objectives: To study the diagnostic accuracy and safety profile of transbronchial lung cryobiopsy and compare with video-assisted thoracoscopic surgery (VATS) by reviewing available evidence from the literature. Methods: Medline and PubMed were searched from inception until December 2016. Data on diagnostic performance were abstracted by constructing two-by-two contingency tables for each study. Data on a priori selected safety outcomes were collected. Risk of bias was assessed with the Quality Assessment of Diagnostic Accuracy Studies tool. Random effects meta-analyses were performed to obtain summary estimates of the diagnostic accuracy. Results: The pooled diagnostic yield, pooled sensitivity, and pooled specificity of transbronchial lung cryobiopsy were 83.7%(76.9-88.8%), 87%(85-89%), and 57%(40-73%), respectively. The pooled diagnostic yield, pooled sensitivity, and pooled specificity of VATS were 92.7% (87.6-95.8%), 91.0% (89-92%), and 58% (31-81%), respectively. The incidence of grade 2 (moderate to severe) endobronchial bleeding after transbronchial lung cryobiopsy and of post-procedural pneumothorax was 4.9% (2.2-10.7%) and 9.5% (5.9-14.9%), respectively. Conclusions: Although the diagnostic test accuracy measures of transbronchial lung cryobiopsy lag behind those of VATS, with an acceptable safety profile and potential cost savings, the former could be considered as an alternative in the evaluation of patients with diffuse parenchymal lung diseases.