Abstract
The commentator found it alarming that we used 15 W and a high LEED in the above mentioned study. As this study on endovenous laser ablation of great saphenous veins, using a 1470 nm diode laser and the radial fibre follow-up after six months, 1 was a proof-of-concept study, we used the power and energy settings for which efficient results have been demonstrated in the past. In the previous studies this was mainly 15 W and a LEED above 60–70 J/cm. 2 The commenter claimed that the use of 4–6 W and 20–50 J/cm with the 1470 nm wavelength is sufficient in his hands. However, for this setting no prospective follow-up study with a follow-up time of more than 6–12 months has been published to our knowledge. In an older study Proebstle could show that a low LEED using the 810 nm laser and a bare fibre showed effective initial occlusion rates but a high recurrence rate after 1–2 years. 3
It is true that theoretically the radial fibre should have some advantages which would allow a lower power and energy density. However, no dose-finding study exists with a sufficient follow-up time showing the most effective energy and power setting with the lowest side-effect rates. The commentator claims that we could demonstrate in an earlier study that a LEED greater than 100 J/cm was associated with a higher rate of paraesthesia. 4 This is true but it has to be mentioned that in this study the mean diameter of the great saphenous vein treated was in the range of 1 cm, which is much higher than the diameter in most of the recent EVLA studies with diameters between 6 and 7 mm. As the effectiveness of EVLA does not only depend on the LEED but also on the EFE with Joule/cm2 vein the diameter of the treated vein also plays an important role for the energy setting chosen. This was the reason for the high energy setting in the previous studies. Also in this recent study the diameter of the great saphenous vein 3 cm distally to the junction was 1 cm.
We agree that lower power and LEED settings should be investigated in prospective randomized studies to find the most effective setting with the lowest complication rates.