Optimizing Outcomes of Laser Tattoo Removal Techniques
In their review study on appropriate device selection and technique of laser tattoo removal, Jeremy Green and Andrei Metelitsa, suggested that practitioners must make the patients aware of the effectiveness of the treatment used for tattoo removal and give them a clear picture of the existing situation to ensure genuine expectation and compliance. Prior consultation with doctor can help educate patients regarding the procedure involved in tattoo removal.
Prior to the treatment, the doctors examine the patient thoroughly to ensure that the patient does not have history of any scar raised over the surrounding skin area and to eliminate the possibility of existence of any infectious disease. Thus, keeping in mind the physical condition of the patient, the tattoo removal treatment may vary from one patient to another. Other than these factors, the type of tattoo also governs the method that needs to be adopted for its removal. Doctors often avoid giving Q switched laser treatment to patients who have received the gold therapy as it may lead to pigmentation of the skin due to deposition of gold in the tissues.
While it is always easier to remove an old tattoo compared to a new one, an amateur tattoo can be removed in four to six treatments. However, the same is not true for professional tattoos which take more time and require eight sessions or more. The location of tattoo also governs the effectiveness and time needed for its removal. Usually tattoos done on acral locations (peripheral parts such as limbs, fingers, ears, etc.) are far more easily removed compared with those done on truncal sites.
In a recent review of 238 patients who underwent tattoo removal treatment, it was found that 1.26 percent of subjects achieved total clearance of the tattoo without reporting any pigmentation. The researchers believe that for other patients the results were less successful because they were being inadequately informed of the process and subsequently, they underwent fewer treatments.
It is mandatory for any practitioner to choose appropriate device for tattoo removal. To achieve selective photo-thermolysis, a QS laser is necessary as the exposure time in the nanosecond (10-9) domain is less than half the thermal relaxation time of the target pigment. The method is effective since it causes minimal damage to surrounding tissue from thermal diffusion. Despite all the guidelines provided, there is a need to understand that the effectiveness of the treatment and selection of tattoo removal methods also depends largely on the composition of the tattoo and the pigment may not necessarily respond to QS laser treatment.
Another device that can be used is QS Nd:YAG when treating tattoos on Fitzpatrick type IV to VI patients. Fitzpatrick classification is a skin type classification depending on skin color and reaction to sun exposure. Skin color varies from brown to black and from 'rarely burn' to 'never burn' reaction to sun exposure in case of type IV to type VI.
Irrespective of the method, practitioner must strive to control the pain in order to ensure that the patient has a pleasant experience. This can be achieved by either by giving topical anesthesia or intra-lesional anesthesia. Once QS laser heat is directed at the tattoo, one can see immediate whitening of the tissue which is due to rapid heating of chromophore that often leads to gas formation. However in case of failure, no such laser-tissue interaction is observed. Multiple wavelengths of light in laser armamentarium are useful to treat modern day professional tattoos.
Another governing factor in the success of the treatment is the utilization of the largest spot possible. Practitioners often reduce the spot to a small size as it results in greater scattering of beam with less penetration. However, this method may increase superficial delivery of energy and damage the epidermis. Application of emollients and occlusive dressing like cooled hydrogel dressing is used to treat the area until the epithelium over the burnt site is naturally recovered.
If the treatment is not done properly, side effects like scarring and dys-pigmentation may start appearing. As epidermal melanin serves as a competing chromophore, it may lead to hypopigmentation or hyperpigmentation.Thus, patients are advised to avoid exposure to sun prior to laser treatment. Pigmentation may also occur as a result of removing cosmetic tattoos that utilizes pink, yellow, white or other colors for permanent makeup. In such cases, it is sensible to perform a test spot prior to treating the entire tattoo.
The second method for tattoo removal is to treat the spot with fractional carbon dioxide erbium.
Although both the methods are widely used for removing tattoos, research is underway to improve both the techniques and devices. The recently invented "R20" method is based on repeating QS laser treatment four times in a single session spaced 20 minutes apart to allow whitening to fade. It is also observed that fractional carbon dioxide laser therapy performed immediately after QS laser treatment can enhance the rate of pigment as compared to QS laser alone.
The researchers are still working on lasers in the picosecond (10-12) domain. A sub-nanosecond pulse can be more effective in confining the energy to the tattoo particle leading to an increased photoacoustic breakup of the target. This will enable more effective treatment utilizing less light that transfers less heat to the surrounding tissue and minimizing the risk of scarring.
Reference: Optimizing Outcomes of Laser Tattoo Removal; Jeremy.B.Green et al; Skin Therapy Letter.com