Suzanne Kilmer, MD
At MauiDerm 2014, Dr Kilmer, an expert in lasers and light devices for dermatological procedures, discusses tattoo removal…
For tattoo removal, we generally use the visible spectrum of light. Years ago, we used CO2 laser or salabrasion for tattoo removal. The use of the CW laser resulted in trans-epidemal loss of ink, significant thermal damage and frequent scarring. The newer Q-Switched Lasers shatters the ink into smaller particles then utilizes macrophages to remove the ink; there is some trans-epidermal loss, yet, there is rarely any scarring.
There are several issues to assess regarding tattoo removal. Pulse duration can be performed in either the nanosecond domain or more recently, the picosecond domain; the picosecond domain may be better for breaking up the ink and it is and may not be as wavelength dependent. Remember that longer wavelengths penetrate deeper and, very importantly, is the fact that the ink’s absorption determines the best wavelength. Fluence/spot size should also be considered. We want the largest spot size; however, we need sufficient fluence. Larger spot sizes allow deeper penetration of effective fluence as long as the laser has sufficient power. Regarding treatment intervals, six to eight weeks is generally the best timing. Of note, dark tattoos are much more easy to treat versus multiple colored tattoos. Green ink responds best to red light and red ink absorbs more in the green light.
Some of the side effects with tattoo removal include ink darkening, incomplete removal of ink, allergic reactions and infections.
Tattoo Treatment Improvements
Over 25 years ago, we went from long pulse to QS laser treatment. QS treatment demonstrated a dramatic improvement in ink reduction and side effect profile. This was the first time that we were able to remove tattoos without scarring. We started with 694nm then added 1064/532 and then 755nm wavelengths in order to improve color removal. This was performed for over 20 years with minimal improvement. In the last two years, we have shortened the pulse width to long pico/ultrashort nanosecond domain. Some studies demonstrated that multiple treatments in the same day increased ink clearance.
Picosecond lasers have a greater photoacoustic effect. In 2012, Cynosure came out with the first picosecond laser and it clearly demonstrated an increased clearance of ink when compared to the QS laser.
Picosecond lasers can also improve ink clearance in resistant tattoos with just two treatments when compared to QS lasers which showed no change over seven treatments.
Another company, Cutera, is looking at using other wavelengths with a novel picosecond laser. They are looking at a 1064nm with 532 component for picosecond domain.
Kossida & Anderson first reported faster tattoo clearing with single versus four treatments on the same day. After treatment, you should wait 20 minutes for whitening to clear “R20”. The photoacoustic effect and shattering of ink particles creates a cavity and as nitrogen gas flows in, you can see whitening. Nitrogen is slow to dissolve out (hence prolonged whitening). A study by Kilmer and Ibrahimi supported repetitive treatment on the same day in order to expedite tattoo clearance. They explored effectiveness of one versus two versus three versus four treatments (to alleviate scheduling nightmares.) They found that two treatments were better than one but then they saw a declining efficacy with further treatment. Geronemus et al used an optical clearing agent, PFD, eliminating the 20-minute interval to clear whitening.
R20 Results-QS Laser
We have found that multiple treatments are better than single treatment on the same day for most tattoos. There is less of a difference between two, three and four treatments on the same day. Increased swelling may occur, as noted by patients and the treating nurse. There was no increase in pain; in fact, most patients felt less pain with subsequent treatment. We also saw no difference in PIPA and no scarring was noted. Generally, all patients preferred a more rapid tattoo clearance.
In summary, ultrashort pulse widths are better, but not always and multi pass is better, usually.
MauiDerm News Editor-Judy Seraphine