Overview
Standard HIFU depth settings may not account for age-related changes in facial tissue layers in women 60 and older. In this exploratory pilot study, 20 women had three HIFU sessions at weeks 0, 4 and 8, using either a conventional protocol or one guided by high-frequency ultrasound measurements. Fat and skin-to-SMAS thickness were measured at baseline and week 16.
Findings
- 20 women, 3 sessions at 4-week intervals, assessed at week 16.
- Both protocols reduced lower face and submental tissue thickness.
- The anatomy-guided protocol showed larger mean reductions on all ultrasound measures.
- Lower face skin-to-SMAS distance: difference -0.19 mm (95% CI, -0.38 to -0.02; p = 0.035).
- Submental superficial fat thickness: -0.20 mm (95% CI, -0.39 to -0.02; p = 0.032).
- Submental skin-to-SMAS distance: -0.19 mm (95% CI, -0.38 to -0.02; p = 0.035).
- These p-values are nominal and unadjusted; the differences are small relative to ultrasound precision.
- Investigator-rated "much improved" or better: 40% conventional, 60% anatomy-guided.
What it means for a patient
- HIFU thinned lower face and under-chin tissue slightly in women over 60 with either protocol.
- Adjusting depth to each person's tissue layers gave a bit more change, but the gap was less than a quarter of a millimeter.
- More women in the individualized group were rated "much improved" by investigators.
- Limits: 20 women, short follow-up, submillimeter differences near the limit of measurement, and unadjusted statistics.
Why this paper matters
It tests whether HIFU depth should be set for each older patient's tissue layers rather than by a standard protocol. The authors call the findings preliminary.
Terms
- HIFU (high-intensity focused ultrasound): focused ultrasound energy that heats tissue under the skin without cutting.
- High-frequency ultrasound (HFUS): detailed imaging used here to measure tissue layer thickness.
- SMAS: the superficial musculoaponeurotic system, a fibrous and muscle layer under the facial fat.
- Submental: under the chin.
- Superficial fat and deep fat: the outer and inner fat layers of the face.
- Nominal, unadjusted p-value: a result not corrected for testing many measures at once, so chance findings are more likely.
- Pilot study: a small early study to test an idea.