Histological analysis of tattoo removal by water cavitation bubbles and jet formation using Nd: YAG and nanosecond laser pulses

Background: For efficient laser tattoo removal, photodisruption of tissue can ensure a very powerful means to shutter ink granules. At very high laser intensity level, photodisruption dominates and selective photothermolysis will have secondary effect in clearing the tattoo ink. Lower laser fluence is all what to trigger non-linear photons absorption and the generation of exploding cavitation bubbles that can tremendously hammer the ink granules. Subjects, materials, and methods: Three domestic white rabbits; each received simultaneous injections of a color pigment tattoo under general anesthesia, followed by a single session of (1064) Q.S Nd: YAG nanosecond laser pulses for tattoo removal. Results and Discussion: Spectroscopic properties of black, dark brown and red tattoo inks were studied. Near threshold laser fluence was selected to select the optimum conditions for obtaining scar-free treatment. Histological images of the biopsies, taken after thirty days of laser treatment of black, dark brown and red tattoos showed a marked reduction in pigment granules size with no appearance of hyperplasia or inflammatory cells. Coexistence of macrophages was suggested to be responsible for actively phagocytizing the laser-dispersed tattoo fragments. Conclusion: skin biopsies have demonstrated ink granules local redistribution. Photodisruption at 1064nm laser effectively targeted black and dark brown tattoo pigments by the generation of cavitation bubbles. The weaker laser light absorption of red pigments at 1064nm only showed tattoo clearance when using 532nm wavelength.

Engineering of Ti:Sapphire Lasers for Dermatology and Aesthetic Medicine

This review describes new engineering solutions for Ti:Sapphire lasers obtained at Laseroptek during the development of laser devices for dermatology and aesthetic medicine. The first device, PALLAS, produces 311 nm radiation by the third harmonic generation of a Ti:Sapphire laser, which possesses similar characteristics to excimer laser-based medical devices for skin treatments. In comparison to excimer lasers, Ti:Sapphire laser services are less expensive, which can save ~10% per year for customers compared to initial excimer laser costs. Here, the required characteristics were obtained due to the application of a new type of diffraction grating for spectral selection. The second device, HELIOS-4, based on the Ti:Sapphire laser, produces 300 mJ, 0.5 ns pulses at 785 nm for tattoo removal. The characteristics of HELIOS-4 exceed those of other tattoo removal laser devices represented in the medical market, despite a simple and inexpensive technical solution. The development of the last laser required the detailed study of a generation process and the investigation of the factors responsible for the synchronization of the generation in Ti: Sapphire lasers with short (several millimeters) cavities. The mechanism that can explain the synchronization in such lasers is suggested. Experiments for the confirmation of this concept are conducted and analyzed.

Picosecond Q-Switched 1064/532 nm Laser in Tattoo Removal: Our Single Center Experience

Background: Tattoo removal is becoming increasingly popular, and Q-switched lasers represent the gold standard in the treatment of this condition. In this study, we report our experience with a new Q-switched picosecond laser device, evaluating its effectiveness and safety. Methods: A total of 34 patients asking for tattoo removal were consecutively enrolled in this open study. The clinicians decided on operating settings based on the Fitzpatrick phototype, the type of tattoo, and the tattoo location. A maximum of seven sessions, with a minimum interval of eight weeks between each session, were performed. At the six month follow-up visit following the last treatment session, patient satisfaction was assessed using a visual analogue scale and two dermatologists evaluated the aesthetic outcome based on pictures taken before and after treatment. Results: A total of 34 patients were included and analyzed: 17 females (50%) and 17 males (50%). The mean patient age was 43.6 ± 11 years. Participants’ Fitzpatrick skin type ranged from II to IV. The mean number of treatment sessions performed was 3.3 ± 2.0 per patient. Over 40% of patients showed complete removal of the tattoo, with most of the patients indicating satisfaction with the treatment. Conclusions: The Q-switched 1064/532 nm laser may be considered the gold standard treatment for tattoo removal. Picosecond pulses seem to guarantee fewer sessions and excellent results when compared to other laser systems in tattoo removal.