Rapid Acoustic Pulse (RAP) is FDA cleared as an adjunct to treat tattoo removal — cellulite could be next.
Rapid Acoustic Pulse (RAP, Soliton), a technology that uses rapid pulses of acoustic waves, is FDA cleared to use as an adjunct to lasers for tattoo removal. The platform’s maker Soliton is investigating the device for other indications, including to treat cellulite, reasoning that noninvasive mechanical stress from the device’s shockwaves might effectively treat cellulite and some scars at the cellular level.
Soliton announced in early November that it completed a trial of 67 cellulite patients using RAP technology. In the company’s initial proof-of-concept (POC) clinical trial, researchers applied the RAP device to the surface of skin with cellulite for a single 20-minute noninvasive treatment. Treatments required no anesthesia, caused no bruising, swelling or infection, and were evaluated by the trial participants as an average of 2.4 on a 0 to 10 pain scale. None of the patients experienced any post-treatment downtime, according to Soliton.
In the POC cellulite trial, the single RAP treatment improved patients’ cellulite severity scores on average from 20% to 47%, according to a recent Soliton investor report.
“We also saw that those results improve even further in 80% of the patients after 6 months suggesting that we may be capable of delivering long-term cellulite reduction,” according to the report.
Histology from an animal study by the company showed evidence that a single 2-minute treatment with RAP completely destroyed or severed fibrous septa in treatment areas. Soliton literature refers to this treatment as acoustic subsicion, which in this case describes RAP’s ability to potentially sever fibrotic septa without breaking the skin.
RAP technology is different than that of extracorporeal shock wave therapy devices on the market, according to a study published September 19, 2019 in Lasers in Surgery and Medicine in which researchers looked at using RAP along with the 1064 nm Nd:YAG Q-switched laser for tattoo removal. Extracorporeal shock wave therapy technologies are like kidney stone lithotripsy devices, which often have reflectors that focus the pressure pulse at very high pressures into an area that is about 2 mm to 3 mm in diameter. With these devices there is risk for nearby tissue damage and pain, according to the study.
There also are devices categorized as therapeutic massagers that usually have slow pressure rise times, low peak pressures and relatively low pulse rates of 10 to 20 per second, according to the authors.
The RAP device differs in that it generates planar acoustic shock wave pulses across a 1.3-inch diameter treatment window, which allows providers to treat larger areas at once, using a fast pulse rate of 100 per second and resulting in shorter treatment times, the authors write.
“Additionally, the RAP pulses are very short in duration (100–200 nanoseconds) with fast rise and fall times to relatively high peak pressures and minimal negative pressures (some other devices have large negative pressures during each pulse cycle that cause cavitation bubbles resulting in pain),” they write.
In their tattoo removal study of 32 black ink tattoos on 21 participants, researchers reported the RAP device used with the 1064 nm Nd:YAG Q-switched laser safely allowed multiple laser treatments in a single office visit by clearing the whitening caused by the previous laser pass. The result, according to the authors, was a notable increase in tattoo fading compared to using the laser alone.
Soliton has plans to analyze data from the larger cellulite pivotal trial in the first quarter of 2020. The RAP device is not yet cleared for treating cellulite or scars.
Kaminer MS, Capelli CC, Sadeghpour M, et al. Increased Tattoo Fading in a Single Laser Tattoo Removal Session Enabled by a Rapid Acoustic Pulse Device: A Prospective Clinical Trial. Lasers Surg Med. 2020;52(1):70-76.