Microfocused ultrasound with visualization: Consensus on safety and review of energy-based devices

Background: Microfocused ultrasound with visualization (MFU-V; Ultherapy^® , Merz North America) is US Food and Drug Administration-cleared as a non-invasive procedure that lifts the soft tissue of the neck, submentum and brow, and improves lines and wrinkles on the upper chest. Several other energy-based devices are in use in countries outside the USA where they are marketed for indications similar to those of MFU-V, although published studies supporting these indications are limited and none of the other devices provides visualization or verification they reach the superficial musculoaponeurotic system.

Methods: Due to the evolving landscape of ultrasound technology as more devices enter the market, seven global thought leaders who are qualified experts on the use of various high-intensity focused ultrasound (HIFU)/MFU-V technologies convened to review data from an independent evaluation of the software, thermal characteristics, transducer acoustics and ultrasound therapy of MFU-V and three other ultrasound-based devices.

Results: The independent testing demonstrated the devices have key differences in several parameters that play a role in safety and effectiveness. Specifically, MFU-V has visualization capability but the other devices lack that feature. Other differences include the retention of patient history, consistent size and uniformity of thermal coagulation points (TCPs), precise localization of energy concentration at the focal point, and reliable thermal regulation during use. The expert panel established a consensus on the types of preventable complications associated with ultrasound-based energy devices and techniques for preventing and treating complications.

Conclusions: The independent test results of MFU-V/HIFU devices and the consensus panel conclusions provide strong support that real-time visualization and the capability to detect coupling, features found only in MFU-V, help prevent complications and enhance the safety and effectiveness of energy-based devices. The independent evaluation also revealed that MFU-V has several additional features that play key roles in safety and clinical effectiveness, including uniformity of TCPs, tight thermal regulation, large focal gain, and short beam length, that were not found collectively in any of the HIFU devices.