title: Performance characteristics of semirigid thoracoscopy in pleural effusions of undetermined etiology.
abstract: BACKGROUND
  The utility of the recently introduced semirigid thoracoscopy in undiagnosed pleural effusions is still unclear.
  
  
  METHODS
  A single-center, 4-year retrospective analysis of all semirigid medical thoracoscopy procedures was done. The diagnostic accuracy of thoracoscopy was calculated as the number of positive diagnoses achieved by thoracoscopy in relation to the end-diagnosis achieved in the patient group by any means.
  
  
  RESULTS
  One hundred fifty procedures were analyzed. Ninety-two patients (62.3%) were diagnosed as having a malignant disorder, of which mesothelioma was the most common (26%). Pleural thickening and nodularity were the most common abnormalities noted. The combined presence of nodules and hemorrhagic fluid increased the likelihood of malignancy 9-fold. Thirteen patients with a high clinical suspicion of malignancy but negative by thoracoscopy underwent mediastinoscopy, computed tomography-guided biopsy, or open thoracotomy. A malignant etiology was confirmed in all of them. Overall, thoracoscopy provided a diagnostic accuracy of 91.3%, sensitivity of 87%, and specificity of 100%. The addition of a second procedure in selected patients improved the diagnostic accuracy for malignancy by 8.7%. The procedures were well tolerated and only 6 patients developed minor and transient complications such as pain, hypoxia, and bradycardia.
  
  
  CONCLUSIONS
  Semirigid thoracoscopy is a safe, well-tolerated, and efficacious procedure for establishing the diagnosis in pleural effusions of undetermined etiology.
authors.affiliation: *All India Institute of Medical Sciences, New Delhi, India †Royal Preston Hospital, Preston, UK.
authors.forename: Anant
authors.initials: A
authors.lastname: Mohan
authors.forename: Samir
authors.initials: S
authors.lastname: Naik
authors.forename: Rehan
authors.initials: R
authors.lastname: Naseer
authors.forename: Cheng
authors.initials: C
authors.lastname: Boon
authors.forename: Janet
authors.initials: J
authors.lastname: Mills
authors.forename: Ravinder M
authors.initials: RM
authors.lastname: Pandey
authors.forename: Mohammed
authors.initials: M
authors.lastname: Munavvar