title: Comparison of heat induced damage at the saphenofemoral junction after ablation with 1,470 nm laser or radiofrequency.
abstract: BACKGROUND
  The aim of this study was to evaluate the heat induced damage at the saphenofemoral junction level according to histopathological changes after radiofrequency or 1,470 nm radial tip laser ablation.
  
  
  METHODS
  Varicose vein segments of 6-10 mm in diameter were exposed to radiofrequency (Closure Fast catheter, 7 cm heat segment, one cycle, 15 seconds, 10 Watt, 120 °C) or laser ablation (1,470 nm radial tip, continuous wave, vein diameter: 6 cm/8 cm/10 cm-power: 10 Watt-pullback speed: 2.2 mm/s, 1.7 mm/s, 1.3 mm/s-LEED: 45J/cm, 60J/cm, 75J/cm-EFE 25J/cm2, respectively). Approximate 2 cm segments of the vein were left untreated, then histopathological examinations of the untouched segments (5 slices: level 1 - furthest segment, level 2 - nearest segment) for heat induced damage were performed. A total damage scoring system was established, including the presence of endothelial swelling, intimal thickening, cellular vacuolisation in the muscle layer, oedema in the tunica media, and extent of necrosis.
  
  
  RESULTS
  At level 1, the furthest segment of the specimen, there was no significant difference between the laser and control group, while the total damage score of the radiofrequency group was significantly higher than the control group (p < 0.01). Radiofrequency group had higher total damage score compared to the laser group at level 1 (p < 0.01), 2 (p < 0.01), and 5 (p < 0.01); while no significant difference was observed at level 3 (p = 0.46) and 4 (p = 0.13).
  
  
  CONCLUSIONS
  Significant heat induced damage may be seen even if the 2 cm segment of the vessel is left unablated. Radiofrequency ablation seems to cause more histological damage than laser ablation in this ex vivo study. Further in vivo studies are necessary, in order to validate these findings.
authors.affiliation: 1 Ankara University, School of Medicine, Cardiovascular Surgery, Ankara, Turkey.
authors.forename: Evren
authors.initials: E
authors.lastname: Ozcinar
authors.affiliation: 1 Ankara University, School of Medicine, Cardiovascular Surgery, Ankara, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Cakici
authors.affiliation: 2 Dr. Siyami Ersek Training and Research Hospital, Cardiovascular Surgery, Istanbul, Turkey.
authors.forename: Oktay
authors.initials: O
authors.lastname: Korun
authors.affiliation: 3 Diskapi Yildirim Beyazid Training and Research Hospital, Pathology, Ankara, Turkey.
authors.forename: Unsal
authors.initials: U
authors.lastname: Han
authors.affiliation: 4 Diskapi Yildirim Beyazid Training and Research Hospital, Cardiovascular Surgery, Ankara, Turkey.
authors.forename: Ugursay
authors.initials: U
authors.lastname: Kiziltepe
mesh_terms: D017115:Catheter Ablation / Q000009:adverse effects* / Q000295:instrumentation; D002908:Chronic Disease; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D053685:Laser Therapy / Q000009:adverse effects* / Q000295:instrumentation; D012501:Saphenous Vein / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D018616:Ultrasonography, Doppler, Duplex; D062666:Vascular Access Devices; D014689:Venous Insufficiency / Q000000981:diagnostic imaging / Q000601:surgery*
keywords: Laser ablation; chronic venous insufficiency; histology; radiofrequency ablation; saphenofemoral junction