Abstract
The article by Pannier et al. adds to the literature yet another interesting small-scale study showing the safety and efficacy of the 1470 nm wavelength for endovenous laser ablation. It was, however, somewhat alarming to read that they chose to use a power setting of 15 W. Casual, non-scientific questioning of colleagues would suggest that the more usual power used with the 1470 wavelength is in the range of 4–6 W for great saphenous vein ablation; however, this has been with bare-tipped fibres. The median wattage used in the Center for Vein Restoration's 15 locations is 4.6 W with a pullback rate of 1 mm/second for the first 10 mm and 2.5 mm/second for the rest of treatment time. However, this is using bare-tipped fibres. Our linear endovenous energy density (LEED) for ablation is generally between 20 and 50 J/cm.
Theoretically, the radial emitting fibre should have some advantages in that the laser energy should be dispersed perpendicularly from the long axis of the fibre. Did the researchers perform prestudy in vitro calibration with the radial fibre to visualize burn pattern or ascertain optimal wattage and pull-back protocol? If so, this would be informative background information. If not, how did the researchers choose their power and pull-back protocol?
In the same authors' work in 2009 they found that LEED of greater than 100 J/cm was associated with a higher rate of paraesthesia. 1
This study had an average LEED of 90 J/cm with a standard deviation of 35.3. We wonder if the rather high wattage selected might have led to through-and-through vein wall perforation and perivenous thermal effects. If so, then vein perforation and perivenous thermal injury might be in part responsible for the 50% pain (without analgesics) and 4% paraesthesia found in this study, which is a rate higher than our experience with the 1470.
It is, nevertheless, reassuring that the complication rate was not higher than reported.
It seems there is a convincing volume of literature showing at least short-term efficacy of the 1470 nm wavelength. This article highlights the present need for research to elucidate the optimal power and LEED for the 1470 that will result in permanent closure with minimal complications.