Meta-analysis and systematic review of mediastinal cryobiopsy versus endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA) in the diagnosis of intrathoracic adenopathy

Abstract

Background: Endobronchial ultrasound (EBUS)-guided mediastinal/hilar cryobiopsy (MedCryoBx) is a relatively new modality, being combined with EBUS-transbronchial needle aspiration (TBNA) to improve yield in the diagnosis of intrathoracic adenopathy. This meta-analysis aims to investigate the diagnostic yield of MedCryoBx versus EBUS-TBNA for intrathoracic adenopathy. Methods: We conducted a systematic search using Google Scholar, Embase, and PubMed/MEDLINE for studies about a diagnosis of intrathoracic adenopathy using MedCryoBx and EBUS-TBNA. Two authors separately reviewed studies for inherent bias using the Quality Assessment Data Abstraction and Synthesis-2 (QUADAS-2) tool. Inverse Variance weighting for random effects methodology was used for meta-analysis. Pooled diagnostic yields overall and for subgroups were estimated. Complications of MedCryoBx were reviewed. Results: Ten studies with 844 patients undergoing either biopsy procedure were in the final analysis. A total of 554 patients underwent MedCryoBx and 704 patients EBUS-TBNA. Meta-analysis showed a pooled diagnostic yield of 91% (504 of 554) for MedCryoBx and 81% (567 of 704) for EBUS-TBNA, with odds ratio (OR) of 2.5 [95% confidence interval (CI): 1.6 to 3.91; P<0.001], with I2 of 20%. Subgroup analysis for benign conditions showed increased diagnostic yield with OR of 7.95 (91% MedCryoBx versus 58% EBUS-TBNA, P<0.001) with an I2 of 25%. Subgroup analysis for lymphoma showed a statistically significant increase in pooled diagnostic yield with OR of 11.48 (87% MedCryoBx versus 29% EBUS-TBNA, P=0.001). Mild bleeding (36.5%) without any intervention was the most common complication. Bleeding requiring intervention (0.7%) was noted in patients. Pneumothorax (0.4%) and pneumomediastinum (0.4%) were less common in this analysis. Conclusions: MedCryoBx is a very promising tool for the diagnosis of intrathoracic adenopathy. It has improved diagnostic yield over EBUS-TBNA in benign and possibly lymphoproliferative diseases, but less so in lung cancer. The complication rates with MedCryoBx are comparable to EBUS-TBNA.