Acute vascular effects of pulsed Nd:YAG high-intensity laser therapy on the deep femoral artery in healthy adults in Greece: a randomized controlled trial

G. Karagianni, L. Barni, D. Travalin, D. Antonakakis, I. Poulis, S. Spanos
Medical Lasers, 2026

Background: High-intensity laser therapy (HILT) is widely used in musculoskeletal rehabilitation for its analgesic and anti-inflammatory effects. Although changes in local circulation have been proposed as a potential mechanism, objective evidence regarding its acute effects on deep arterial structures remains limited. This study evaluated the acute effects of pulsed Nd:YAG 1,064 nm HILT on Doppler-derived blood flow velocity and pressure-gradient estimates in the deep femoral artery of healthy adults.
Methods: Twenty-eight healthy adults were randomly assigned to an active HILT group (n = 14) or a sham group (n = 14). The active intervention consisted of a single session of 3 kW pulsed Nd:YAG laser applied to the quadriceps. The sham group underwent identical procedures without laser emission. Color Doppler ultrasound assessed blood flow velocity and pressure-gradient estimates before and after intervention.
Results: In the HILT group, mean blood flow velocity increased from 66.21 ± 6.49 cm/s to 76.14 ± 5.32 cm/s (p < 0.001), whereas no significant change was observed in the sham group (p = 0.257). Pressure-gradient estimates also increased significantly in the HILT group, from 1.57 ± 0.36 mmHg to 2.16 ± 0.49 mmHg (p < 0.001). No significant between-group difference was found after the intervention (p = 0.062).
Conclusion: A single session of pulsed Nd:YAG HILT induced acute changes in Doppler-derived hemodynamic parameters. These preliminary findings suggest an acute hemodynamic response but do not demonstrate increased blood flow, tissue perfusion, or clinical efficacy. Further studies with larger samples using direct flow and microcirculatory measurements are needed.