title: Liver abscess after percutaneous radiofrequency ablation for hepatocellular carcinomas: frequency and risk factors.
abstract: OBJECTIVE
  The purpose of this study was to clarify the frequency and risk factors of liver abscess formation after percutaneous radiofrequency ablation in patients with hepatocellular carcinoma.
  
  
  METHODS
  Over a 4-year period, 603 patients with 831 hepatocellular carcinomas measuring 5 cm or less in maximum diameter who underwent a total of 751 percutaneous radiofrequency ablation procedures were enrolled in this study. We retrospectively reviewed the medical records and analyzed the overall frequency of liver abscess, risk factors for abscess, and clinical features of the patients. The relationships between liver abscess and potential risk factors were analyzed using either generalized estimating equations or multiple logistic regression analysis.
  
  
  RESULTS
  Liver abscess developed in 14 tumors of 13 patients after 13 (13/751 [1.7%]) ablation procedures. Generalized estimating equations and multiple logistic regression analysis of various potential risk factors revealed that preexisting biliary abnormality prone to ascending biliary infection (p = 0.0088), tumor with retention of iodized oil from previous transcatheter arterial chemoembolization (p = 0.040), and treatment with an internally cooled electrode system (p = 0.016) were associated with a significant risk of liver abscess formation. No patient died of liver abscess, and all successfully recovered from liver abscess with parenteral antibiotics and percutaneous clearance of pus.
  
  
  CONCLUSIONS
  Although liver abscess formation was infrequent in patients who underwent percutaneous radiofrequency ablation for hepatocellular carcinoma, the patients with significant risk factors-preexisting biliary abnormality prone to ascending biliary infection, tumor with retention of iodized oil, and treatment with an internally cooled electrode system-for liver abscess formation should be closely monitored after treatment.
authors.affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-dong, Kangnam-ku, Seoul 135-710, South Korea.
authors.forename: Dongil
authors.initials: D
authors.lastname: Choi
authors.forename: Hyo K
authors.initials: HK
authors.lastname: Lim
authors.forename: Min Ju
authors.initials: MJ
authors.lastname: Kim
authors.forename: Suk Jung
authors.initials: SJ
authors.lastname: Kim
authors.forename: Seung Hoon
authors.initials: SH
authors.lastname: Kim
authors.forename: Won Jae
authors.initials: WJ
authors.lastname: Lee
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Lim
authors.forename: Seung Woon
authors.initials: SW
authors.lastname: Paik
authors.forename: Byung Chul
authors.initials: BC
authors.lastname: Yoo
authors.forename: Moon Seok
authors.initials: MS
authors.lastname: Choi
authors.forename: Seonwoo
authors.initials: S
authors.lastname: Kim
mesh_terms: D000772:Anesthesia, Local; D006528:Carcinoma, Hepatocellular / Q000601:surgery*; D017115:Catheter Ablation; D016292:Procedural Sedation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008100:Liver Abscess / Q000175:diagnosis / Q000453:epidemiology*; D008103:Liver Cirrhosis / Q000453:epidemiology; D008113:Liver Neoplasms / Q000601:surgery*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D014057:Tomography, X-Ray Computed