Background High-intensity focused ultrasound (HIFU) operating at 20 MHz is new and potentially applicable to ablative tattoo removal. The method was documented safe and rational in preclinical testing. Materials and Methods High-intensity focused ultrasound was introduced to subjects when lasers and dermatome shaving had failed or caused side effects. Transducers with focal depths between 1.1 mm and 1.7 mm in the skin were used, and settings of 0.4-1.2 J/shot at pulse durations of 150 ms were applied. Tattoos were covered with synergistic "shoulder-by-shoulder" focused ultrasound shots. Effectiveness and side effects were measured. Results Twenty-two subjects with 67 tattoos were treated. 62% benefitted (19% cleared, 43% partially cleared), and 28% had minor effect. VAS pain was 5-6 versus 7-9 with previous lasers removal. Wound healing was longer after HIFU ablation (1-3 months). 57% of subjects had no scar or minor visible changes of skin surface markings only, while 19% had moderate or major skin thickening. Hypertrophic scar or keloid scars were not observed. Discussion/Conclusion High-intensity focused ultrasound was effective in removal of difficult tattoos of any color where Nd:YAG lasers had failed. The method only needs 1-3 sessions. As an ablative method, the wound healing period is longer than with laser removal and needs attention. Focused ultrasound can be used as a first-line treatment of smaller tattoos independent of color, and second line when Nd:YAG lasers have failed or caused problems. The operator shall be qualified, as with lasers.
