title: Pneumothorax induced by radiofrequency ablation for hepatocellular carcinoma beneath the diaphragm under real-time computed tomography-fluoroscopic guidance.
abstract: BACKGROUND
  Various treatments for hepatocellular carcinoma (HCC) beneath the diaphragm have been reported. Transpulmonary radiofrequency (TPRF) ablation for HCC beneath the diaphragm has been developed as a safe treatment, but pneumothorax has been reported as the most common complication of TPRF ablation.
  
  
  OBJECTIVE
  To evaluate the relationship between the incidence of pneumothorax and various variables after TPRF ablation.
  
  
  METHODS
  Seventy-six TPRF ablation sessions for unresectable HCC were performed in 66 patients (19 women, 47 men; mean age 69.6 years) under computed tomography (CT)-fluoroscopic guidance between November 2005 and April 2009. All patients had HCC beneath the diaphragm, not visible by ultrasonography. In 62 of the 76 sessions, the number of transpulmonary approaches was one as adequate, while multiple transpulmonary approaches were performed in 14 of the 76 sessions. The rate of pneumothorax and risk factors for pneumothorax were investigated.
  
  
  RESULTS
  Among the 76 sessions, pneumothorax was detected in 51 sessions (67.1%). Among the 14 sessions with multiple transpulmonary passages, pneumothorax was detected in 13 (92.9%), while in the 62 sessions with a single transpulmonary passage, pneumothorax occurred in 38 sessions (61.3%). Hence, the number of transpulmonary approaches was a significant factor (P=0.0232). Among 13 variables investigated for the 62 sessions with a single transpulmonary approach, the only significant factor correlated with the occurrence of pneumothorax was the length of the needle trajectory through the aerated lung (P=0.0014). The incidence of chest tube placement was 7.9%.
  
  
  CONCLUSIONS
  Pneumothorax occurred frequently after TPRF ablation for HCC. The main risk factors for pneumothorax after TPRF ablation for HCC were increased length of needle trajectory through the aerated lung and multiple transpulmonary approaches in one session. Even if pneumothorax occurred, pneumothorax disappeared spontaneously or with simple treatment such as manual aspiration in most cases.
authors.affiliation: Department of Radiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-chyou, Kyoto, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miura
authors.forename: Takuji
authors.initials: T
authors.lastname: Yamagami
authors.forename: Koshi
authors.initials: K
authors.lastname: Terayama
authors.forename: Rika
authors.initials: R
authors.lastname: Yoshimatsu
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Tsunehiko
authors.initials: T
authors.lastname: Nishimura
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects* / Q000706:statistics & numerical data; D003964:Diaphragm; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D008113:Liver Neoplasms / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011030:Pneumothorax / Q000453:epidemiology / Q000209:etiology*; D014057:Tomography, X-Ray Computed