A novel device integrates micro-focused ultrasound with high-resolution ultrasound visualization (MFU-V) to cause sub-dermal collagen denaturation and subsequent de novo collagen synthesis and remodeling.1,2 When applied to areas of lax skin, the result is significant skin lifting and tightening.3-7 MFU-V has been demonstrated to be safe and effective in numerous clinical trials as a noninvasive aesthetic treatment, and it is FDA-cleared to non-invasively lift tissues of the eyebrow, neck, and submentum (UltheraÂ® System; Ulthera, Inc., Mesa, AZ).8
Despite the similarities in age-related changes in the skin and connective tissue, the clinical presentation of each patient is unique, and MFU-V treatment must be customized for each patient. The MVU-V device uses six transducers that emit ultrasound energy at a range of frequencies and at multiple focal depths.8 Each ultrasound transducer can also provide tissue imaging to a depth of 8 mm. The MFU-V device utilizes a computer-driven platform that enables the clinician to visualize the proposed treatment with ultrasound-imaging transducers and develop a treatment plan prior to applying micro-focused ultrasound energy.
Using these transducers, micro-focused ultrasound is delivered in a series of lines at discrete tissue depths, including the variable depths of the superficial muscular aponeurotic system. Thermal coagulation points are formed when ultrasound energy is focused to a point less than 1 mm3 in size below the skin surface. At such points, 95% of the delivered ultrasound energy is converted to heat, thereby raising the local temperature to ~65Â°C. At this temperature, denaturation and contraction of collagen and stimulation of neocollagenesis occurs while the superficial layer of skin and other intervening tissues remain unaffected.2 Each line of treatment consists of a row of thermal coagulation points at a single focal depth. These treatment lines are typically spaced 2-3 mm apart.
MFU-V has proven to be effective for lifting and tightening lax skin on the face and neck when focused ultrasound is delivered at a single focal depth.3-6 The present nonrandomized, prospective study was performed to determine whether the customized application of MFU-V at two focal depths can produce improved clinical results compared to treatment at a single focal depth.
The study enrolled 71 healthy men and women that were 30 to 65 years of age and expressed interest in MFU-V for lifting and tightening of the face and neck. Subjects were required to have