LAUSR

BACKGROUND Adverse vascular event management following hyaluronic acid-based aesthetic injections relies on the administration of hyaluronidase which is capable to enzymatically degrade the injected product and to improve clinical symptoms. Two protocols are currently available to manage such complications: "ultrasound guided targeted" and "flooding". OBJECTIVES To compare the 2 protocols by means of amount of hyaluronidase volume utilized, and onset and degree of clinical improvement. METHODS A comparative case series of 39 patients was retrospectively evaluated which were initially treated with the "flooding" protocol and then treated with the "ultrasound guided targeted" due to no or little improvement. RESULTS The "ultrasound-guided targeted" protocol utilized a total of 122.5 iu (34) whereas the "flooding" protocol utilized 1519.4 iu (1137) which represents a statistically significant reduced amount of injected hyaluronidase with p = 0.028. There was no clinical improvement in 92.3% and only little improvement in 7.7% of the treated patients following the first applied "flooding" protocol but there was a 100% immediate improvement when treated with the "ultrasound-guided targeted" protocol. Ultrasound imaging revealed that the application of hyaluronidase normal blood flow was restored both in the perivascular space and in the superficially located subdermal soft tissues. CONCLUSIONS Despite its limitations in study design, this retrospectively evaluated case series revealed that the ultrasound guided targeted protocol utilized less hyaluronidase material and restored faster clinically visible symptoms. The effect of this protocol is best explained by the perforasome concept which will need to be investigated further in future studies.