Temperature changes in perivenous tissue during endovenous laser treatment in a swine model

To conduct a pilot study to measure temperature at the outer vein wall during endovenous laser treatment (EVLT).

Temperature at the outer vein wall was monitored during EVLT in a live pig ear vein (8 W: 1.0 and 2.0 seconds pulse duration; 10 W: 1.0 and 1.5 second pulse duration; 12 W: 0.5, 1.0 and 1.5 second pulse duration) and exposed hind limb vein (8 W: 0.5, 1.0, 1.5 second pulse duration; 12 W: 0.5,1.0, 1.5 second pulse duration with perivenous tumescent fluid (TF); and 15 W: 0.5 second pulse duration without and with TF, 1.0 second pulse duration with TF).

Peak temperatures, near the outer vein wall in an ear vein of a live pig, with laser fluence at 8 W were 40.8 degrees C and 48.9 degrees C (pulse durations of 1.0 and 2.0 seconds, respectively). At 10 W, peak temperature was 47.1 degrees C and 49.1 degrees C (pulse durations of 1.0 and 1.5 seconds, respectively). At 12 W, peak temperature ranged from 37.9 degrees C (0.5 second pulse duration) to 49.1 degrees C (1.5 second pulse durations). In an exposed hind limb vessel, at 8 W, peak temperature ranged between 34.6 degrees C to 38.5 degrees C (0.5, 1.0 and 1.5 second pulse durations). At 12 W and 0.5 to 1.5 second pulse durations, with TF, peak temperature ranged from 35.6 degrees C to 39.4 degrees C. At 15 W and 0.5 second pulse duration, peak temperature was 44.0 degrees C without TF and 34.5 degrees C with TF. At 15 W and 1.0 second pulse duration, with TF, pulse duration peak temperature was 37.0 degrees C.

In the model studied, peak temperatures of perivenous tissues generated during endovenous laser seem unlikely to cause permanent damage to these perivenous tissues. The peak temperature generated is reduced with the use of perivenous tumescent fluid.