Quantitative Correlation Between Hyaluronic Acid Filler and Hyaluronidase

Abstract

The hyaluronic acid-based filler (HA filler) is used worldwide in various applications. In particular, the HA filler is used in the plastics and cosmetic medical field for facial rejuvenation and contouring. In this setting, it is injected into the skin or underlying tissue. Complications of HA filler injection have been relieved using hyaluronidase. However, there is no standard dose to adjust for undesirable HA filler lumpness. In this study, the authors tried to analyze any quantitative correlation between HA filler and hyaluronidase. The back of each rat (total 14 rats) was divided into 4 sites. A volume of 0.5 mL HA filler was injected into the subdermal layer at each site and HA filler nodules were created on the dorsum of each rat. Each nodule was allocated to groups 1, 2, 3, and 4 according to the different concentrations of hyaluronidase. As a result, the injected HA filler volume doubled within 4 days of injection, and then decreased slowly thereafter in group 1 (control group with normal saline only). A 30 unit hyaluronidase treatment compensated for the initial volume increase (approximately 30%) with HA filler (0.5 ml) at the fourth day. Sixty units of hyaluronidase reduced the initial volume (0.5 mL) of overinjected or misplaced HA filler on the fourth day. Approximately 90 units of hyaluronidase can reduce to the volume by 0.25 mL (50%) of the injected HA filler on the fourth day. The authors believe that this quantitative analysis of hyaluronidase concentration is helpful to plan the amount of hyaluronidase for correction of HA filler injection errors.

Early ultrasound for diagnosis and treatment of vascular adverse events with hyaluronic acid fillers

“…46,47 To overcome this issue in urgent cases of intravascular occlusion, higher doses of hyaluronidase are recommended to compensate for possible relative resistance of the gel to degradation. [46][47][48][49][50] However, with ultrasonographically guided injection of hyaluronidase, an average injected dose of 35 to 60 units per deposit was sufficient in most cases, independent of the type of HA filler used. A possible explanation may be that precise injection into the targeted HA deposit requires fewer units.…”

Evaluation of hyaluronic acid gel dissolution with hyaluronidase in an in-vitro prostate cancer model

“…It has the capacity to hold water, which allows for reliable, reproducible injections which is of great interest in rectal spacing in prostate cancer radiotherapy to decrease radiation dose to the rectum. Despite the relatively high safety profile, several complications of HA fillers have been reported in other clinical setting like esthetic surgery, including granulomatous reactions, lumpiness, and skin necrosis [11] .…”

“…Next, additional factors are influencing the interaction of HA and HAS, including, location of injection, and injection techniques [11] .…”

Prevention and Management of Filler Induced Iatrogenic Stroke of the Eye

“…Several studies have examined the relative effectiveness of Hase on a variety of HASF products and demonstrated a varying level of responsiveness. [58][59][60][61][62] The timeline for the change in the state of HASF from solid, palpable material to a liquid that might flow away and resolve an obstruction, maybe in the range of 3-6 hours. Studies in animal models have shown necrosis is reduced when Hase treatment is initiated within 4 hr of vascular occlusion.…”