title: Pneumothorax, pleural effusion, and chest tube placement after radiofrequency ablation of lung tumors: incidence and risk factors.
abstract: OBJECTIVE
  To retrospectively evaluate the incidence of and risk factors for pneumothorax, pleural effusion, and chest tube placement for pneumothorax after radiofrequency (RF) ablation of lung tumors.
  
  
  METHODS
  Institutional review board approval was obtained, with waiver of informed consent. This retrospective study comprised 224 ablation sessions for 392 tumors in 142 patients (92 men, 50 women; mean age, 64.0 years). Multiple variables were analyzed by using the Student t test or the Mann-Whitney U test for numerical values and by using the chi(2) test or the Fisher exact test for categorical values in order to assess risk factors for pneumothorax, pleural effusion, and chest tube placement for pneumothorax.
  
  
  RESULTS
  The incidence of pneumothorax, pleural effusion, and chest tube placement for pneumothorax was 52% (117 of 224 sessions), 19% (42 of 224 sessions), and 21% (24 of 117 sessions), respectively. For pneumothorax, risk factors included male sex (P = .030), no history of pulmonary surgery (P < .001), a greater number of tumors ablated (P < .001), involvement of the middle or lower lobe (P = .008), and increased length of the aerated lung traversed by the electrode (P = .014). For pleural effusion, risk factors included the use of a cluster electrode (P = .008), decreased distance to the nearest pleura (P = .040), and decreased length of the aerated lung traversed by the electrode (P = .019). For chest tube placement for pneumothorax, risk factors included no history of pulmonary surgery (P = .002), the use of a cluster electrode (P < .001), and involvement of the upper lobe (P < .001).
  
  
  CONCLUSIONS
  Pneumothorax and pleural effusion can occur after RF ablation in patients with lung tumors, and chest tube placement for pneumothorax is sometimes required.
authors.affiliation: Departments of Radiology and Cancer and Thoracic Surgery, Okayama University Medical School, 2-5-1 Shikatacho, Okayama 700-8558, Japan. takaoh@tc4.so-net.ne.jp
authors.forename: Takao
authors.initials: T
authors.lastname: Hiraki
authors.forename: Nobuhisa
authors.initials: N
authors.lastname: Tajiri
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Mimura
authors.forename: Kotaro
authors.initials: K
authors.lastname: Yasui
authors.forename: Hideo
authors.initials: H
authors.lastname: Gobara
authors.forename: Takashi
authors.initials: T
authors.lastname: Mukai
authors.forename: Soichiro
authors.initials: S
authors.lastname: Hase
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Fujiwara
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Iguchi
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Sano
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Shimizu
authors.forename: Susumu
authors.initials: S
authors.lastname: Kanazawa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017115:Catheter Ablation; D015505:Chest Tubes; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010996:Pleural Effusion / Q000453:epidemiology / Q000209:etiology*; D011030:Pneumothorax / Q000453:epidemiology / Q000209:etiology* / Q000601:surgery; D011183:Postoperative Complications; D012189:Retrospective Studies; D012307:Risk Factors; D013907:Thoracostomy