title: Factors influencing pneumothorax rate at lung biopsy: are dwell time and angle of pleural puncture contributing factors?
abstract: OBJECTIVE
  To study factors that may influence pneumothorax and chest tube placement rate, especially needle dwell time and pleural puncture angle.
  
  
  METHODS
  In 159 patients, 160 coaxial computed tomography (CT)-guided lung biopsies were performed. Dwell time, the time between pleural puncture and needle removal, was calculated. The smallest angle of the needle with the pleura ("needle-pleural angle") was measured. These and other variables were correlated with pneumothorax and chest tube rates.
  
  
  RESULTS
  One hundred fifty biopsies were included. There were 58 (39%) pneumothoraces (14 noted only at CT), with eight (5%) biopsies resulting in chest tube placement. Longer dwell times (mean, 29 minutes; range, 12-66 minutes) did not correlate with pneumothoraces (P =.81). Smaller needle-pleural angles (< 80 degrees) [corrected], decreased forced expiratory volume in 1 second to vital capacity ratio (<50%), lateral pleural puncture, and lesions along fissures were associated with higher [corrected] pneumothorax rates (P <.05). Emphysema along the needle path, pulmonary function tests showing ventilatory obstruction, and lesions along fissures predisposed patients to chest tube placement (P <.05). Pleural thickening and prior surgery were associated with lower pneumothorax rates (P <.05).
  
  
  CONCLUSIONS
  Longer dwell times do not correlate with pneumothorax and should not influence the decision to obtain more biopsy samples. A shallow pleural puncture angle may increase the pneumothorax rate.
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Boston, USA. jane.ko@med.nyu.edu
authors.forename: J P
authors.initials: JP
authors.lastname: Ko
authors.forename: J O
authors.initials: JO
authors.lastname: Shepard
authors.forename: E A
authors.initials: EA
authors.lastname: Drucker
authors.forename: S L
authors.initials: SL
authors.lastname: Aquino
authors.forename: A
authors.initials: A
authors.lastname: Sharma
authors.forename: B
authors.initials: B
authors.lastname: Sabloff
authors.forename: E
authors.initials: E
authors.lastname: Halpern
authors.forename: T C
authors.initials: TC
authors.lastname: McLoud
mesh_terms: D000368:Aged; D001707:Biopsy, Needle / Q000009:adverse effects*; D015505:Chest Tubes / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008168:Lung / Q000473:pathology*; D008297:Male; D010994:Pleura; D011030:Pneumothorax / Q000453:epidemiology / Q000209:etiology*; D011446:Prospective Studies; D011677:Punctures; D013997:Time Factors; D014057:Tomography, X-Ray Computed