New devices modify noninvasive skin tightening

Nashville, Tenn. - The pioneering 1,320 nm Nd:YAG laser, and, more recently, the long-pulsed 1,064 nm Nd:YAG, the 1,450 nm Nd:YAG and the 1,540 nm Er:glass lasers, though working superficially, have been used with varying degrees of success to treat acne scars, surgical scars and fine wrinkles - yet to achieve a more dramatic skin tightening, deeper heating is required, according to one expert.

Revolutionary nonablative skin resurfacing devices that cause a noninvasive heating of the dermis modify collagen structure and stimulate neocollagenesis.

"A number of approaches have now been developed in an effort to achieve this goal," says Brian S. Biesman, M.D., assistant clinical professor of the divisions of ophthalmology, otolaryngology and dermatology at Vanderbilt University Medical Center, Nashville, Tenn.

According to Dr. Biesman, ThermaCool™ (Thermage®, Inc.) is a monopolar radiofrequency (RF) delivery system that uses capacitive coupling technology to create uniform energy distribution across the entire electrode surface with subsequent volumetric tissue heating. This unique system avoids the accumulation of energy at the electrode's periphery that occurs with standard RF devices.

The ThermaCool™ device delivers RF energy with a maximum fluence of 225 J/cm² , heating tissue in a uniform fashion with peak temperatures (thought to be 55 degrees C to 70 degrees C from histopathologic findings) centered approximately 2 mm to 3 mm beneath the surface. It also has a unique cooling system integrated in the handpiece, using a cryogen spray to internally cool the electrode, before, during and after energy delivery.

Dr. Biesman cites the first multicenter United States study with ThermaCool™, in which patients received a single treatment for their crow's feet and in the forehead regions. Results showed Fitzpatrick wrinkle score to improve by at least one point in at least 83 percent of treated periorbital areas, and after six months, 50 percent of patients indicated satisfaction with periorbital wrinkle reduction. Also, 61 percent of eyebrows were lifted by at least 0.5 mm.

The initial treatments were extremely painful, and in a small but significant number of cases, fat atrophy developed, of which only some resolved spontaneously.

"Today, however, it is unfair to evaluate the performance of the Thermage® device based on this early experience, as both treatment tip technology and the treatment algorithm have changed dramatically over the past two years. Advances in the disposable tip technology decreased the treatment cycle duration from six to 1.9 seconds, making it possible to treat large areas more efficiently. Simultaneously, it was demonstrated clinically that a greater number of passes performed at lower fluence was better tolerated by patients and produced greater, more predictable skin tightening with a ten-fold lower risk of subcutaneous fat atrophy," Dr. Biesman says.

According to Dr. Biesman, patients are treated to an endpoint of visual tightening, and treatments are typically administered without topical anesthesia or IV sedation. He adds that Kaminer, et. al., demonstrated that approximately 94 percent of patients treated with the multiple pass/low fluence algorithm showed visible skin tightening at the time of treatment.

"In my opinion, the greatest clinical efficacy is produced with treatment of the midface, lower face and neck. Often overlooked is the qualitative improvement in skin quality related to enhanced collagen production. Despite these improvements though, clinical results still widely vary. Some patients achieve marked tissue tightening and/or lifting, while others demonstrate only minimal improvement," Dr. Biesman says.

In his own research, Dr. Biesman successfully demonstrated safety and efficacy in treating eyelids within the orbital rim, using a 0.25 cm² treatment tip that is designed to deliver heat more superficially, thus permitting safe use around the eyes.

In his multicenter study in which the upper and lower eyelids and crow's feet region were treated, there was no injury caused to either the eyelids or the globes themselves. Dr. Biesman used specially designed plastic corneoscleral protective lenses (Oculoplastik, LaserSecure). Treatments were well tolerated without supplemental anesthesia.