Advances in Minimally Invasive and Noninvasive Treatments for Submental Fat

Cryolipolysis

Cryolipolysis is an advancement that utilizes the application of noninvasive cooling temperatures to the skin’s surface to destroy underlying adipocytes based on the concept that lipid-filled cells are more susceptible to cold-induced injury than water-filled cells. Thus, cryolipolysis selectively targets adipose tissue, leading to cell death without harm to surrounding cells and without the need for surgery or injections.¹⁴

Cryolipolysis typically is delivered via a vacuum applicator (CoolMini, Zeltiq Aesthetics Inc), which applies temperatures of –10°C (14°F) to the skin in cycles of 60 minutes each. Initially approved by the FDA for treatment of flank adiposity in 2010, cryolipolysis has since been approved for treatment of the abdomen, thighs, and submental area.¹⁴ An advantage of cryolipolysis is that it does not require frequent treatment sessions for maximal efficacy.

Efficacy

The efficacy of cryolipolysis in the treatment of SMF was established in a multicenter device investigation resulting in its FDA approval for the submental region.¹⁵ Sixty participants with a mean BMI of 31.8 kg/m² received 1 (1/60) or 2 (59/60) treatment sessions of the submental area administered 6 weeks apart. Primary efficacy assessments included analysis by 3 blinded reviewers who viewed photographs of each participant at baseline, immediately posttreatment, 6 weeks posttreatment, and 12 weeks posttreatment; ultrasonographic measurements of SMF thickness; and a 12-point patient satisfaction questionnaire. Blinded reviewers correctly identified baseline images in 91.4% (55/60) of cases. Ultrasonography confirmed a mean reduction in SMF of 2 mm (P<.0001) or 20% of fat thickness at 12 weeks posttreatment. On subjective patient satisfaction surveys, 83% (50/60) of participants were satisfied with the procedure and 77% (46/60) reported a visible reduction in fat and perceived an improvement in appearance.¹⁵

Safety

The most common immediate posttreatment AEs were erythema/purpura (100%), numbness (90%), edema (62%), tingling (30%), blanching (25%), and bruising (3%) at the site of cryolipolysis with resolution within 1 week posttreatment, except for numbness.¹⁵ At 6-week follow-up, all AEs had resolved, except continued numbness in 4 participants that resolved by 12-week follow-up. A further event of note was fullness in the throat in 1 participant that was attributed to swelling and resolved at 40 days posttreatment without incident. No serious AEs were reported in this trial.¹⁵

A particularly concerning but rare complication that is increasing in awareness is paradoxical adipose hyperplasia following cryolipolysis. Patients may develop firm painless areas of soft tissue enlargements in the area of cryolipolysis typically 3 to 6 months posttreatment.¹⁶ The largest published report recorded an incidence rate of 0.46% (n=2, all males) at a single-center institution of 422 cryolipolysis treatments.¹⁶ Other incidence rates reported are 0.0051% and 0.78%.¹⁷ Causes and associations are not known, though male gender is speculated to increase risk.

Conclusion

This article highlights the available information on advances in minimally invasive and noninvasive treatments for SMF accumulation. The efficacy and safety trials varied in quality and in different methods of end point analysis of SMF reduction. Further, few trials have featured head-to-head comparisons of treatments.

Although liposuction and adjuncts remain the gold standard in large-mass lipid removal, these procedures are invasive and exhibit typical risks of surgery. Given its sensitive location, the submental area may require the use of more delicate therapeutic methods, including completely noninvasive devices such as truSculpt and cryolipolysis. Regardless of the chosen treatment, the most important factors in yielding patient satisfaction and SMF improvement are proper patient selection and an understanding of the anatomical source of adiposity to be addressed with the therapeutic modalities.