computed tomography guided transthoracic lung biopsy: evaluating risk factors of post-procedure pneumothorax- a multivariate analysis

Background: ct guided lung biopsy is a common procedure in our department and pneumothorax is one of its commonest complications. to study the incidence of pneumothorax after ct guided lung biopsy and the various factors associated with the risk of developing pneumothorax after biopsy.materials and methods: our study was a retrospective observational study. we ana-lyzed 360 cases of lung biopsy performed using 18g coaxial needle for assessing the incidence of post- procedure pneumothorax. the risk factors for pneumothorax were evaluated by univariate analysis, followed by multivariate logistic regression analysis to know the independent risk factors of pneumothorax.results: the incidence of pneumothorax in our study was 41.9% (151/360 cases). on univariate analysis, we identified the following as risk factors of post-procedure pneumothorax: the presence of emphysema, smaller lesion size, greater lesion depth, lateral position, multiple passes and acute angulation of needle trajectory. on mul-tivariate logistic regression analysis these were also revealed to be independent risk factors of post-procedure pneumothorax.conclusion: independent risk factors of post procedure pneumothorax are the presence of emphysema, smaller lesion size, greater lesion depth, lateral position, multiple passes and acute angulation of needle trajectory. of these lateral position is a novel predictor of pneumothorax that has been scarcely mentioned in literature. as such the radiologist should be prepared for managing pneumothorax in cases with one or more of these risk factors.