A new platform for bipolar radiofrequency-assisted liposuction (RFAL; BodyTite, Invasix) is promising technology for performing body contouring in an outpatient setting under local anesthesia. However, achieving safe and successful outcomes requires careful technique and patient selection, says Spero J. Theodorou, M.D.
Dr. Theodorou has been a clinical investigator for the RFAL platform that is pending approval by the Food and Drug Administration, but it is commercially available in Europe and Canada. Speaking at the 2011 Cutting Edge Aesthetic Surgery Symposium, he described the procedure, appropriate candidates, and results achieved in 97 prospectively evaluated patients who underwent RFAL using tumescent anesthesia (Theodorou SJ, Paresi RJ, Chia CT. Aesthetic Plast Surg. 2012;36(4):767-779\). The procedures were performed by Dr. Theodorou and his partner, Christopher T. Chia, M.D., and included a total of 144 anatomical areas with an average aspirate of 1,146 cc per anatomical area.
"The RFAL platform for body contouring is a powerful piece of equipment with a steep learning curve and has the potential to cause complications when used by unskilled hands," says Dr. Theodorou, who is in private practice and is an attending surgeon, department of plastic surgery, Manhattan Eye, Ear & Throat Hospital, New York."However, plastic surgeons have the expertise to use this technology safely and effectively, and we should be on the forefront of its adoption because it offers an opportunity to meet the needs of patients looking for a minimally invasive body contouring procedure," he says.
HOW IT WORKS The RFAL procedure results in fat removal and skin shrinkage with decreased blood loss. Tissue heating is caused as energy is transferred between an internal and an external probe. The heating leads to defragmentation and liquefaction of fat cells, which are removed by aspiration, while coagulating blood vessels and ultimately causing contraction and retraction of dermal tissue.
The platform features an integrated monitoring system that shuts off the radiofrequency power once the preset temperature is reached.
"In our practice, we set the target temperature to between 38 and 40 degrees and used a power setting in the range of 35 to 40 W, which is lower than reported by others. However, we believe our more conservative parameters allow for more gradual and uniform heating that improves tolerability for the patient while also reducing the risk of complications," Dr. Theodorou says. The tissue contraction that occurs with the treatment occurs in three dimensions and is mediated through the septo-fascial system, he adds.
"This technology does not just heat the underside of the dermis, but it causes full thickness heating, recruiting the deep fascial system," Dr. Theodorou says. "The ability to achieve this soft tissue contraction without skin resection involving lengthy incisions helps justify using RFAL, despite its having a higher complication rate than traditional liposuction that does not utilize energy assistance."
PATIENT SELECTION Considering its benefits and mechanism for producing subdermal contraction, Dr. Theodorou says that appropriate candidates for the procedure have moderate-to-severe skin laxity with a moderate amount of adiposity and no irreversible dermal damage.
"The most important consideration in choosing candidates for RFAL is to not overpromise on the results. RFAL body contouring is not a substitute for excisional surgery, but it has the advantage of being a procedure that is feasible using local anesthesia, and it doesn't burn any bridges to preclude subsequent excisional surgery," he says.
In order to provide adequate analgesia, the tumescent anesthetic solution used for the RFAL procedure must be relatively potent. Relative to the tumescent technique originally described by Klein, the tumescent anesthetic used by Drs. Theodorou and Chia contains higher concentrations of epinephrine (1.5 mL/L vs. 1.0 mL/L) and lidocaine (0.15 percent vs. 0.10 percent).
"In our study including 97 patients, the average lidocaine dose was 32.7 mg/kg body weight, consistent with the recommendation in the plastic surgery literature not to exceed 35 mg/kg. However, the range was up to 83.3 mg/kg, and the amount exceeded the 35 mg/kg threshold in one-third of the operations," Dr. Theodorou says.
"One patient in our series developed perioral tingling that we attributed to lidocaine toxicity. However, this individual underwent three consecutive operations in three days and did not have any other problems. Based on our experience and other reports, it appears that administering higher concentrations of lidocaine in tumescent fluid may be safe, but further studies are needed," he adds.