2016 Volume 37 Issue 2 Pages 159-164
Laser ablation has been widely accepted as the modality for the treatment of primary varicose veins. The interaction between laser light and living tissue is complex, and aspects of it remain unclear, but deepening our understanding of the interaction will enable selection of more appropriate laser ablation parameters and lead to reduced side effects and improved safety and results of treatment.
Ultrasound tomography revealed very little thrombus in the lumens of ablated veins treated with the 1470 nm-wavelength diode laser and 2-ring radial fiber, which are prevalent in Japan. No blood flow was seen in lumens narrowed by marked wall thickening and reductions in their diameter, and instead we observed hypoechoic, ultrasound tomography images that tended to be compressed in the center of the lumens. These hypoechoic sites persisted for about 3-6 months, and subsequently were assimilated by the overall process of fibrosis and disappeared.
Optical extinction rate of the water-specific laser wavelength (1470 nm) light in biological tissue was high, and with a small amount of energy the laser caused thermal damage that extended to the entire circumference and full thickness of the tunica intima.Because new blood inflow routes were cut off, no thrombus was formed, and it appeared that due to the relatively mild degree of thermal injury, the wound healing response progressed slowly.
