Development and Usability of a Virtual Reality-Based Filler Injection Training System

Purpose

As filler procedures have increased in popularity, serious injection-related complications (e.g., blindness and stroke) have also increased in number. Proper and effective training is important for filler procedure safety; however, limitations exist in traditional training methods (i.e. anatomical illustrations and cadaver studies). We aimed to describe the development process and evaluate the usability of a virtual reality (VR)-based aesthetic filler injection training system.

Materials and Methods

We developed the virtual reality hardware for the training system and a short guide, with a lecture regarding safe filler injection techniques. One hundred clinicians who attended a conference tested the training system. Participants completed system usability scale (SUS) and satisfaction questionnaires.

Results

Nearly half of the participants were aged 35–50 years, and 38% had more than 5 years of aesthetic experience. The mean SUS score was 59.8 (standard deviation, 12.23), with no significant differences among the evaluated subgroups. Approximately 76% of participants provided SUS scores of more than 51, indicating acceptable usability. Participants aged 35–50 years were more likely to rate the system as having poor usability than were those aged < 35 years (odds ratio = 5.20, 95% confidence interval: 1.35–20.08).

Conclusions

This study was the first to develop and explore the usability of a VR-based filler training system. Nearly three-fourths of participants indicated that the training system has an acceptable level of usability. However, assessments in precise target audiences and more detailed usability information are necessary to further refine the training system.

Level of evidence IV

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Electronic supplementary material

The online version of this article (10.1007/s00266-020-01872-2) contains supplementary material, which is available to authorized users.

Intravascular injections of adenoassociated viral vector serotypes rh10 and PHP.B transduce murine sciatic nerve axons

Adenoassociated viral vectors provide a safe and robust method for expression of transgenes in nondividing cells such as neurons. Intravenous injections of these vectors provide a means of transducing motoneurons of peripheral nerves. Previous research has demonstrated that serotypes 1, rh10 and PHP.B can transduce motor neuron cell bodies in the spinal cord, but has not quantified expression in the peripheral nerve axon. Axonal labeling is crucial for optogenetic stimulation and detection of action potentials in peripheral nerve. Therefore, in this study, serotypes 1, PHP.B, and rh10 were tested for their ability to label axons of the murine sciatic and tibial nerve following intravenous injection. Serotype rh10 elicits expression in 10% of acetylcholine transferase positive axons of the sciatic nerve in immunohistochemically-stained sections. Serotype rh10 transduces a variety of axon diameters from <1-12 μm, while PHP.B transduces larger axons of diameter (4-16 μm). Expression was not seen with serotype 1. These results show the potential of serotypes PHP.B and rh10 delivery of transgenic products to axons of the peripheral nerve.

Experience and Management of Intravascular Injection with Facial Fillers: Results of a Multinational Survey of Experienced Injectors

BACKGROUND

Intravascular injection leading to skin necrosis or blindness is the most serious complication of facial injection with fillers. It may be underreported and the outcome of cases are unclear. Early recognitions of the symptoms and signs may facilitate prompt treatment if it does occur avoiding the potential sequelae of intravascular injection.

OBJECTIVES

To determine the frequency of intravascular injection among experienced injectors, the outcomes of these intravascular events, and the management strategies.

METHODS

An internet-based survey was sent to 127 injectors worldwide who act as trainers for dermal fillers globally.

RESULTS

Of the 52 respondents from 16 countries, 71 % had ≥11 years of injection experience, and 62 % reported one or more intravascular injections. The most frequent initial signs were minor livedo (63 % of cases), pallor (41 %), and symptoms of pain (37 %). Mildness/absence of pain was a feature of 47 % of events. Hyaluronidase (5 to >500 U) was used immediately on diagnosis to treat 86 % of cases. The most commonly affected areas were the nasolabial fold and nose (39 % each). Of all the cases, only 7 % suffered moderate scarring requiring surface treatments. Uneventful healing was the usual outcome, with 86 % being resolved within 14 days.

CONCLUSION

Intravascular injection with fillers can occur even at the hands of experienced injectors. It may not be always associated with immediate pain or other classical symptoms and signs. Prompt effective management leads to favorable outcomes, and will prevent catastrophic consequences such as skin necrosis. Intravascular injection leading to blindness may not be salvageable and needs further study.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .