title: An investigation of the relationship between energy density and endovenous laser ablation success: does energy density matter?
abstract: OBJECTIVE
  To assess the relationship between energy density and the success of endovenous laser ablation (EVLA) treatment.
  
  
  METHODS
  A total of 586 EVLAs were performed in a period of 35 months. Retrospective chart review was performed, and data collected included the patients' age, sex, and history of venous stripping procedures, as well as the name, laterality, and length of the treated vein segment(s) and the total energy delivered. Energy density was calculated by dividing total energy delivered (in J) by the length of vein (in cm). Energy density selection was based on the treating interventionalist's preference. Ablated segments were grouped into those treated with less than 60 J/cm, 60-80 J/cm, 81-100 J/cm, and more than 100 J/cm. Failure of EVLA was defined by recanalization of any portion of the treated vein during follow-up as assessed by duplex Doppler ultrasound examination. Failure rates were compared with the chi(2) test and Wilcoxon rank-sum test.
  
  
  RESULTS
  A total of 471 segments were included in the analysis with an average follow-up period of 5 months (range, 0.2-28.7 months). Overall, 11 failures were encountered, including four in the group treated with less than 60 J/cm (n = 109; 4%), two in the 60-80-J/cm group (n = 77; 3%), four in the 81-100-J/cm group (n = 169; 3%), and one in the group treated with more than 100 J/cm (n = 116; 1%). There was no statistically significant difference in failure rates among energy density ranges.
  
  
  CONCLUSIONS
  EVLA has a low failure rate that is not affected by energy density.
authors.affiliation: Department of Diagnostic Imaging, Rhode Island Hospital, The Warren Alpert School of Medicine at Brown University, 593 Eddy Street, Providence, RI 02903, USA. eprince@lifespan.org
authors.forename: Ethan A
authors.initials: EA
authors.lastname: Prince
authors.forename: Sun H
authors.initials: SH
authors.lastname: Ahn
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Dubel
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Soares