title: Risk factors for pneumothorax complicating radiofrequency ablation for lung malignancy: a systematic review and meta-analysis.
abstract: OBJECTIVE
  To assess the potential risk factors for pneumothorax secondary to pulmonary radiofrequency (RF) ablation.
  
  
  METHODS
  Six electronic databases were searched from inception to February 2014 for studies assessing potential patient-related, tumor-related, or treatment-related risk factors for pneumothorax during pulmonary RF ablation. Study selection, data collection, and quality assessment were done by three independent reviewers.
  
  
  RESULTS
  Among 771 studies identified in the search, 10 retrospective cohort studies met inclusion criteria. There were 981 patients (61.5% male) with a mean age of 64.2 years included (259 primary lung tumors, 722 metastatic tumors). The prevalence of pneumothorax was 37% (95% confidence interval [CI], 29%-46%) in 1,916 RF ablation sessions. The potential patient-related and tumor-related risk factors for pneumothorax were increased age (mean difference [MD], 2.09; 95% CI [0.11-4.06]; I(2) = 0%), male gender (unadjusted odds ratio [OR], 2.20; 95% CI [1.49-3.27]; I(2) = 0%), no history of lung surgery (unadjusted OR, 0.29; 95% CI [0.19-0.44]; I(2) = 0%), and a greater number of tumors ablated (MD, 0.50; 95% CI [0.27-0.73]; I(2) = 0%).
  
  
  CONCLUSIONS
  Based on available observational studies, the results suggest risk factors for pneumothorax secondary to pulmonary RF ablation may include increased age, male gender, no history of lung surgery, number of tumors ablated, and increased length of the aerated lung traversed by the electrode. The findings from this systematic review should be interpreted with caution because of the inherent limitations of the retrospective observational design.
authors.affiliation: Michael G. DeGroote School of Medicine, McMaster University, 1200 Main Street West, Hamilton, Ontario L7P 4V9, Canada.
authors.forename: Sean A
authors.initials: SA
authors.lastname: Kennedy
authors.affiliation: Michael G. DeGroote School of Medicine, McMaster University, 1200 Main Street West, Hamilton, Ontario L7P 4V9, Canada.
authors.forename: Lazar
authors.initials: L
authors.lastname: Milovanovic
authors.affiliation: Department of Surgery, McMaster University, 1200 Main Street West, Hamilton, Ontario L7P 4V9, Canada.; Department of Clinical Epidemiology and Biostatistics, McMaster University, 1200 Main Street West, Hamilton, Ontario L7P 4V9, Canada.
authors.forename: Dyda
authors.initials: D
authors.lastname: Dao
authors.affiliation: Department of Surgery, McMaster University, 1200 Main Street West, Hamilton, Ontario L7P 4V9, Canada.; Department of Clinical Epidemiology and Biostatistics, McMaster University, 1200 Main Street West, Hamilton, Ontario L7P 4V9, Canada.
authors.forename: Forough
authors.initials: F
authors.lastname: Farrokhyar
authors.affiliation: Department of Diagnostic Imaging, McMaster University, 1200 Main Street West, Hamilton, Ontario L7P 4V9, Canada.. Electronic address: midia@hhsc.ca.
authors.forename: Mehran
authors.initials: M
authors.lastname: Midia
mesh_terms: D017115:Catheter Ablation / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D008175:Lung Neoplasms / Q000601:surgery*; D011030:Pneumothorax / Q000209:etiology*; D011183:Postoperative Complications / Q000209:etiology*; D012307:Risk Factors