Abstract
Since this study was submitted for publication, an additional 148 treatments have been followed until the entire segment of treated vein became absent on duplex ultrasound scan (DUS). There was one additional failed treatment detected. This failure was the entire 54 cm segment of a 15 mm diameter great saphenous vein (GSV) in a 50-year-old man with a body mass index of 28.5. The energy delivered to the vein was 111 J/cm and 31 J/cm2. With 11 failures out of a total of 664 treatments, the overall success rate of the entire series is 98.3%. All treatments have been performed using a bare-tipped laser fibre and an 810 diode laser (Diomed, Inc.). Analysis of this additional data yields some interesting observations.
Table 7 shows that there is a statistically significant difference in the amount of energy delivered between the successful and the failed treatments. This is true whether the energy is expressed in J/cm or J/cm2.
Energy delivery in successful and failed treatments
Table 8 divides the 664 treatments into three separate chronological time periods according to the amount of power (watts) utilized and the method of energy delivery (pulsed versus continuous). As the power was increased for each period there was a statistically significant increase in energy delivery and a corresponding increase in the success rate. This data suggests that utilizing a power setting of 14 watts (continuous delivery mode) to deliver a minimum of 120 J/cm and a minimum of 50 J/cm2 will yield a 100% success rate.
Success rates during three periods of increasing energy delivery
The only complications seen in these 148 additional treatments were three instances of temporary paresthesia (2.0%). The additional data included in this addendum further substantiates the observation that greater amounts of energy yield greater success rates. Also, the greater levels of energy discussed herein can be delivered without increased complications, as long as adequate tumescent anaesthesia is utilized.