Bridging a Century-Old Problem: The Pathophysiology and Molecular Mechanisms of HA Filler-Induced Vascular Occlusion (FIVO)-Implications for Therapeutic Interventions

A novel empirical and rheometric assessment of viscoelastic hydrogel implant cohesiveness

Therapeutic implantable hydrogels are increasingly utilized in medicine due to their versatile viscoelastic properties. Nonetheless, the clinical efficacy and longevity of these products is predicated on their ability to retain structural integrity post-implantation. Gel cohesion, defined as the capacity to resist fragmentation, has lacked empirical standardization, especially in high shear environments, with present methods often conflating this mechanical parameter with gel ductility or qualitative perceptions of tackiness. In this study, we introduce a novel quantitative method of cohesion analysis termed the Modulus of Cohesion (MOC). The MOC is derived from rheometric strain sweep testing by calculating the difference between the elastic and viscous moduli from 0% strain to the crossover point. This novel parameter provides a direct measure of mechanical energy storage and dissipation balance, accounting for linear and nonlinear deformation in shear strain. Eleven commercially available hyaluronic acid gels are evaluated using this method, alongside uniaxial tension and drop weight methods to establish correlations between MOC and existing cohesion metrics. Additionally, haptic sensory analysis and aqueous dispersion methods from previous reports are correlated with rheometric and mechanical tests. Our results demonstrate that MOC provides a reliable, reproducible measure of gel cohesiveness, correlating strongly with other quantitative methods with augmented precision.

Essential Pharmaceutical Drugs in the Filler Emergency Kit

INTRODUCTION

The rise in clinical procedures utilizing dermal fillers necessitates preparedness for potential emergencies. Effective management of complications arising from filler use, including vascular occlusions and allergic reactions, hinges on the availability of the appropriate pharmacological supplies.

METHODS

A two-tiered search in PubMed and Google Scholar was conducted to identify essential drugs for dermal filler emergencies. An initial 10-year review used keywords "Dermal Fillers," "vascular occlusion," and "hyaluronidase," followed by a targeted search on "Resuscitation guidelines," "anaphylaxis management," "allergy fillers," and "lidocaine." This article outlines the critical drug inventory for emergency kits to manage filler-related complications effectively.

RESULTS

An ORA classification system (Obligatory, Recommended, Advisable) is introduced to categorize essential drugs according to urgency and clinical necessity. The required drugs are grouped based on their application in cases of vascular occlusion without ocular involvement, vascular occlusion with ocular involvement, anaphylactic reactions, cardiopulmonary resuscitation and hemodynamic disorders, delayed reactions, and aseptic, oxygen, and topical treatments. Additionally, the importance of meticulous drug inventory management-including tracking of stock entry, exit, and expiration dates-is emphasized to reduce the risk of shortages.

CONCLUSION

Ensuring that filler emergency kit is well stocked with vital pharmacological supplies is imperative for effective emergency management during filler procedures. Adopting systematic inventory practices and utilizing the ORA classification can enhance preparedness and patient safety.

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 .

Retrobulbar Hyaluronidase in Hyaluronic Acid-Induced Ocular Vascular Occlusion: Efficacy, Challenges, and Implications for Clinical Practice

INTRODUCTION

Ophthalmic vascular occlusion due to hyaluronic acid (OVOH) is a rare but devastating complication of cosmetic filler injections, often resulting in severe vision loss.

MATERIALS

The methodology involved a systematic search across PubMed, NCBI, Google Scholar, and Cochrane to investigate factors influencing central retinal artery occlusion (CRAO) caused by fillers. Searches focused on "eye vascular anatomy," "ocular physiology in response to ischemia," "components AND hyaluronic acid AND inflammation," "recovery from blindness associated with fillers," "retrobulbar technique," and "hyaluronidase degradation AND fillers." This review examines the pathophysiology, clinical presentation, and management of OVOH by synthesizing findings from case reports, clinical studies, and experimental research. It elucidates retinal vascular anatomy, HA embolization mechanisms, and treatment efficacy, highlighting the critical importance of timely intervention.

RESULTS

OVOH typically presents with rapid vision loss within minutes of HA injection, often accompanied by severe ocular pain. The primary treatment, hyaluronidase (HYAL), is most effective when administered early, although retrobulbar HYAL shows limited overall success. Factors such as ischemia duration and the presence of cilioretinal arteries significantly influence retinal survival and recovery. The review discusses the complexities of retinal hypoxia and the implications of various intervention strategies.

CONCLUSION

Timely intervention is crucial for managing OVOH. Although retrobulbar HYAL remains a key treatment option, its effectiveness varies and necessitates optimization. Early and accurate diagnosis is essential, underscoring the need for further research to refine treatment strategies and improve outcomes for patients with retinal vascular occlusions.

LEVEL OF EVIDENCE IV

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 .

The Shifting Face of Aesthetic Care: A Systematic Survey of Independent Medical Spa Directorship and Practitioner Trends in Florida

BACKGROUND

The rapid proliferation of medical spas (med spas) in the United States has raised concerns over the continued shift of nonsurgical aesthetic treatments away from traditional core specialty integration and supervision, potentially affecting surgical treatment guidance and education of cosmetic surgery patients. The authors assessed trends in the growth of independent med spa facilities as well as practitioner supervision, licensing, and specialization in the state of Florida.

METHODS

The authors performed a comprehensive, statewide survey of all independent med spas in Florida by municipality using online business search engines. Information gathered included the number of locations, business stakeholders, and director or practitioner licensing and certification obtained from the Florida Division of Corporations or Department of Health databases and respective medical boards.

RESULTS

A total of 1038 med spas were identified, revealing a 100% increase in number relative to 2021 estimates. Nonphysician practitioners represented 84% of med spa providers, with core specialty medical director supervision present in only 22% of facilities and a large proportion of directors lacking specialty training (77%) or board certification (42%). In addition, 25% of med spas appeared to disregard state guidelines pertaining to medical directorship, autonomous nonphysician practice, and numeric or geographic restrictions on directorship, with 96% of facilities lacking licensing or registration with Florida's Agency for Health Care Administration.

CONCLUSIONS

Med spa growth in Florida has been explosive, with continued departure from core supervision, increasingly limited specialty training and integration, and nonadherence to state guidelines. Enhanced regulation and integrated nonphysician practitioner training are likely necessary to ensure patient safety and the cohesive practice of aesthetic medicine and surgery.

Correction: Soares, D.J. Bridging a Century-Old Problem: The Pathophysiology and Molecular Mechanisms of HA Filler-Induced Vascular Occlusion (FIVO)-Implications for Therapeutic Interventions. Molecules 2022, 27, 5398

In the original publication [...].

Good scientific practice of using worldwide post-marketing surveillance data to ensure safety with HAALI BDDE cross-linked hyaluronic acid fillers

Background

Aliaxin fillers (HAALI), produced by IBSA Farmaceutici Italia SrL (Italy), are biodegradable, non-pyrogenic, 1,4-butanediol diglycidyl ether cross-linked hyaluronic acid (HA) hydrogels. The formulations are tailored for different clinical indications, ensuring precise and natural outcomes. Their cohesivity and tissue integration capabilities are associated with relatively few adverse events (AEs), supporting their widespread use in aesthetic treatments. This article examines the real-world safety profile of HAALI fillers derived from worldwide post-marketing surveillance data.

Methods

Post-marketing surveillance was registered by the manufacturer from January 2018 to September 2023. During this period, product complaints were globally gathered from healthcare practitioners and consumers, relating to technical issues or safety and product-related adverse events.

Results

No discernible trend or substantial escalation in AEs across the entire product range were observed during the surveillance period (p>0.05). No statistically significant increases (p>0.05) in the frequency or severity of safety incidents and AEs were observed. The most frequently observed AEs were oedema (26%) and swelling (19%).

Conclusion

The analysed data further support and confirm the high safety profile of the HAALI fillers for different approaches in aesthetic medicine. This evaluation also highlights the importance of post-marketing analysis by continuing to foster a robust understanding of products currently used in daily clinical practice.

Might Topical Heparin Help With Occlusion Emergencies After Accidental Intra-Arterial Hyaluronic Acid Injections?

Hyaluronic acid fillers rarely cause potentially devastating occlusive adverse events that require immediate hyaluronidase salvage infiltrations. An exploratory photographic investigation probed whether topical heparin's anticlotting and anti-inflammatory properties could synergize with and enhance the effectiveness of hyaluronidase. Based on heparin pharmacodynamics, the authors explored the rationale for associating topical heparins with hyaluronidase in treating occlusive side effects following accidental intra-arterial hyaluronic acid injections. In the first case, an occlusion in the right superior labial artery area, highlighted by reddish-blue net-like skin discoloration (livedo reticularis), developed below the nasal pyramid shortly after 3 intradermal injections of low-viscosity hyaluronic acid gel, rapidly progressing to the glabellar and forehead regions. Within 1 h after the hyaluronidase salvage injection (80 IU), topical low-molecular-weight heparin (40 mg enoxaparin) was uniformly applied, and the procedure was repeated every 8 h for 15 days. In the second case, a cluster of severe occlusive lesions developed in the nose and nasal tip areas after 3 hyaluronic acid injections (formulation and doses as previously stated). After the first week, enoxaparin (4000 IU) was applied topically every 8 h for an additional 3 weeks. Two sequences of photographs document the occlusions' evolution toward almost complete skin repair after 28 days (first case: immediate combined treatment) and 15 days (second case: sequential treatment spaced 1 week).The anti-inflammatory and antithrombotic pharmacodynamics of heparin and heparin derivatives offer a promising rationale as an add-on option (combined hyaluronidase and topical heparin) to treat the occlusive side effects caused by hyaluronic acid.

Level of Evidence 5 Therapeutic

Partially Reversible Episode of Blindness after Intravascular Hyaluronic Acid Filler Injection

Blindness from hyaluronic acid filler injections is an uncommon but devastating complication. We present a case of blindness related to a "skin booster." It is often assumed that skin boosters have no risk of visual problems, and this case underlines the need to understand products' rheology and chemistry. Given the lack of agreed consensus in bedside and secondary care management, it is important to report and describe all cases of vision loss caused by fillers, including assessment and management, to allow understanding of what may give rise to better outcomes.

Vascular complications with necrotic lesions following filler injections: Literature systematic review

INTRODUCTION

Although the related risk of vascular necrosis due to filler injection is low, the outcomes can be severe when they occur. This systematic review aims to report the occurrence and treatment of vascular necrosis due to filler injection.

MATERIALS AND METHODS

The systematic review was performed according to PRISMA guidelines.

RESULTS

The results showed the most used treatment is a combination of pharmacologic therapy and hyaluronidase application, which is efficacy when applied in the first 4 h. In addition, even though management recommendations are available in literature, proper guidelines are unavailable due to the low number of complications occurrence.

CONCLUSION

Clinical and high-quality studies on treatment and management of filler injection combination are necessary to provide scientific evidence on what to do in case of vascular complication occurrence.

A High Likelihood of a Disastrous Outcome: A Case Report of a Complication From the Cosmetic Use of Hyaluronic Acid

Hyaluronic acid (HA) injections are a generally safe procedure, primarily performed to achieve a more aesthetically appealing appearance. Despite the safety of HA filler procedures, complications may arise in some individuals, such as tenderness, lumpiness, swelling, bruising, neurological impairments, embolism, soft-tissue necrosis, irreversible scarring, and baldness. We present a case of a 36-year-old previously healthy female who was injected with HA filler (Juvederm Voluma®) into the nasolabial folds for cosmetic purposes. A few hours later, she reported feeling pain in her right nasolabial region; 27 hours after the injection, the patient presented with a violaceous rash and was diagnosed clinically with arterial compromise due to HA injection 27 hours prior. She was managed with aspirin and hyaluronidase injections into the affected area. The complication resolved after two weeks of follow-up. HA used in our patient was very heavy in its molecular characteristics, and it should not be injected in the nasolabial fold. HA injections can lead to various complications, and both practitioners and patients should be aware of these potential adverse effects. Prompt intervention is required to ensure recovery from vascular occlusion in these patients.

"Filler-Associated Acute Stroke Syndrome": Classification, Predictive Modelling of Hyaluronidase Efficacy, and Updated Case Review on Neurological and Visual Complications

INTRODUCTION

The rising use of soft tissue fillers for aesthetic procedures has seen an increase in complications, including vascular occlusions and neurological symptoms that resemble stroke. This study synthesizes information on central nervous system (CNS) complications post-filler injections and evaluates the effectiveness of hyaluronidase (HYAL) treatment.

METHODS

A thorough search of multiple databases, including PubMed, EMBASE, Scopus, Web of Science, Google Scholar, and Cochrane, focused on publications from January 2014 to January 2024. Criteria for inclusion covered reviews and case reports that documented CNS complications related to soft tissue fillers. Advanced statistical and computational techniques, including logistic regression, machine learning, and Bayesian analysis, were utilized to dissect the factors influencing therapeutic outcomes.

RESULTS

The analysis integrated findings from 20 reviews and systematic analyses, with 379 cases reported since 2018. Hyaluronic acid (HA) was the most commonly used filler, particularly in nasal region injections. The average age of patients was 38, with a notable increase in case reports in 2020. Initial presentation data revealed that 60.9% of patients experienced no light perception, while ptosis and ophthalmoplegia were present in 54.3 and 42.7% of cases, respectively. The statistical and machine learning analyses did not establish a significant linkage between the HYAL dosage and patient recovery; however, the injection site emerged as a critical determinant.

CONCLUSION

The study concludes that HYAL treatment, while vital for managing complications, varies in effectiveness based on the injection site and the timing of administration. The non-Newtonian characteristics of HA fillers may also affect the incidence of complications. The findings advocate for tailored treatment strategies incorporating individual patient variables, emphasizing prompt and precise intervention to mitigate the adverse effects of soft tissue fillers.

LEVEL OF EVIDENCE III

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 .

Histological Assessment of the Effectiveness of Microneedling Device-Assisted Filler Delivery

BACKGROUND

Microneedling is used to enhance transcutaneous drug delivery. However, the extent to which microneedling devices impact filler delivery and whether this varies by filler type, microneedling device type, and treatment sequence is not known.

OBJECTIVE

To histologically assess and quantify the delivery of commonly used fillers through microneedling, using both a microneedling pen and a microneedling roller. In addition, the authors investigated whether there is a variation in filler delivery based on the sequence of microneedling in relation to topical filler application.

METHODS

Ex vivo human abdominal skin samples were subjected to microneedling pen or microneedling roller treatment. Black tissue marking ink, hyaluronic acid, poly- l -lactic acid, or undiluted calcium hydroxyapatite was topically applied before or immediately after microneedling treatment.

RESULTS

Histological evaluation revealed a notable presence of black ink within channels formed by both microneedling treatments (15.5%-98.1%), whereas there was limited presence of the various filler types tested (0%-6.6%) in all settings. Topical application before microneedling treatment led to relatively higher filler/ink deposition within the channels formed by the microneedling treatments compared with topical application after microneedling.

CONCLUSION

Transcutaneous delivery of fillers was not significantly helped by microneedling treatment, whereas the microneedling devices demonstrated effective delivery of an aqueous solution.

Resolution of Vascular Compromise From Liquid Rhinoplasty Using Hirudo medicinalis Therapy

Hyaluronic acid (HA) fillers are a relatively safe and effective means of cosmetic treatment for the face; however, as the numbers of both patients and injectors continue to rise, reports of adverse events (AEs) and ischemia are increasing. Although visual complications and stroke are the most-feared AEs, skin and underlying tissue necrosis is far more common and can be catastrophic. HA can be dissolved with hyaluronidase, but this does not always resolve ischemia. In some instances, including the case presented here, conventional interventions are inadequate to reverse the progression of ischemia and restore blood flow. In this case study, HA injection of the nasal sidewall resulted in ischemia and impending necrosis of the nasal tip. Following failure of standard-of-care measures to reverse the progression of ischemia and restore blood flow, Hirudo medicinalis therapy was successfully used as an adjuvant treatment. To our knowledge, this is the first report of H. medicinalis therapy for treatment of ischemia and necrosis from aesthetic filler injection. Based on experience here, this approach should be considered for patients who are out of therapeutic options, or as a helpful adjunct to speed resolution of vascular occlusion. In addition, the success of H. medicinalis therapy, which acts locally on the microvasculature, may inform our understanding of the mechanism of vascular occlusion with fillers.

Level of Evidence 5 Therapeutic

The Impact of Gel Parameters on the Dispersal and Fragmentation of Hyaluronic Acid Gel Fillers within an Artificial Model of Arterial Embolism

Accidental arterial embolization of hyaluronic acid (HA) fillers can lead to severe complications, including skin ischemia, blindness, and stroke. Currently, the intra-arterial dispersal and fragmentation behavior of HA gels is unknown but critical to our understanding of the pathomechanism of these injuries. This work introduces the Pulsatile Unit for the Laboratory Simulation of Arterio-embolic Restrictions (PULSAR) and evaluates the intravascular behavior of different HA gels. The fragmentation and dispersal behaviors of four HA gels with distinct rheological properties were evaluated via high-resolution videography and ImageJ particle size and morphology analysis. The gels' elastic modulus (G'), loss modulus (G″), tan(δ), and HA concentration were subsequently correlated with their intra-arterial behaviors. This study effectively confirms the extensive fragmentation of HA gels upon arterial inoculation, with particle sizes ranging from <50 µm to >1 mm. Gel particle size and morphology correlated most significantly with tan(δ). Conversely, arterial flow rates did not significantly influence gel fragmentation behavior, though the probability of proximal, macrovascular obstruction was affected. Overall, this study validates the PULSAR model for simulation of arterial dynamics and the testing of intravascular filler kinematics. The findings demonstrate the ability of gels to microfragment and disseminate distally, as well as induce partial proximal occlusion depending on gel rheology and arterial flow parameters.

Role of Hyperbaric Oxygen in Filler-Induced Vascular Occlusion

INTRODUCTION

The rising incidence of filler-induced vascular complications in the context of aesthetic procedures necessitates a thorough assessment of therapeutic options. Hyperbaric oxygen therapy (HBOT) has emerged as a potential intervention for filler-induced vascular occlusion (FIVO), although optimal dosing and timing remain undefined.

METHODS

This review explores the pathophysiology of FIVO and elucidates HBOT's multifaceted role in salvaging ischemic tissue. The physical and biochemical mechanisms of HBOT, including its vasodilatory, anti-spasmodic, and anti-inflammatory effects, are examined.

RESULTS

HBOT serves as an adjunctive therapy in FIVO management, emphasizing timely intervention, adherence to specific pressures (two atmosphere absolute), and session durations (60 minutes) to optimize efficacy and minimize complications. While existing HBOT protocols for compromised grafts provide insights, standardized guidelines for FIVO are lacking.

CONCLUSION

HBOT enhances tissue oxygenation, modulates reactive oxygen species, and influences angiogenesis and hypoxia response. However, it does not replace key treatment protocols for filler vascular complications. Further research and standardized protocols are warranted to define HBOT's definitive role in mitigating filler-induced vascular complications. Level of Evidence IV 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 .

Dilutional rheology of Radiesse: Implications for regeneration and vascular safety

BACKGROUND

Calcium hydroxylapatite-carboxymethylcellulose (CaHA-CMC) injectables have emerged as dual-purpose fillers with bioregenerative and direct filling capabilities.

AIMS

This study investigates the rheological properties of CaHA-CMC and its CMC carrier gel at various dilutions.

METHODS

The storage modulus (G'), loss modulus (G″), complex viscosity (η*), loss factor (tan δ), cohesivity, and extrusion force were evaluated for a range of CaHA-CMC aqueous dilutions with an oscillatory rheometer, drop weight testing, and force analysis, respectively.

RESULTS

Results revealed a significant decrease in G', η*, and increase in tan(δ) with increasing dilution, indicating a decline in the product's direct filling capabilities. Cohesivity decreased dramatically with dilution, potentially enhancing tissue biointegration and the product's biostimulatory effects. The CMC gel carrier displayed inelastic and non-resilient properties, with rheological changes differing from CaHA-CMC. Dilutional rheology was also correlated with previously published dilution-dependent biostimulatory data where hyperdiluted CaHA-CMC (>1:2) demonstrated a regenerative profile and diluted or hypodiluted mixtures retained meaningful filling properties and increased regeneration.

CONCLUSIONS

These findings offer a continuum for tailoring the product's rheological profile to match specific tissue requirements. Customizable rheology allows CaHA-CMC to be tuned for either filling and contouring or optimal regenerative effects. Importantly, safety implications related to vascular occlusion suggest that dilutional rheomodulation decreases the risk of vascular events. In conclusion, this study highlights the significant impact of aqueous dilution on the rheological properties of CaHA-CMC and its carrier gel. The findings support the clinical application of tailored dilutions to achieve desired outcomes, providing versatility and safety for aesthetic applications.

Practice-Based Learning in Aesthetic Medicine: Assessing Scientific Literacy Among Cosmetic Practitioners

BACKGROUND

The field of aesthetic medicine has expanded substantially in the past decade, with significant practitioner diversification and departure from core-specialty supervision. The increased autonomy of nonphysician practitioners in a rapidly evolving field has raised accentuated the importance of scientific literacy and practice-based learning standards in the delivery of aesthetic medical care.

OBJECTIVE

To assess the degree of scientific literacy among aesthetic medicine practitioners of different educational and training backgrounds in the United States and abroad.

MATERIALS AND METHODS

A cross-sectional survey of 52 national and international aesthetic medicine practitioners employing a validated, 28-item, scientific literacy tool.

RESULTS

The average score for all participants was 76% (SD = 18%, range = 43%-100%). Physician practitioners scored higher in all competencies compared non-physicians (86% vs 68%, p < 0.001), with a greater discrepancy among US practitioners (95% vs 71%, p < 0.001). Competencies relating to identification of bias/confounding variables, graphical data representation, and statistical inference/correlation showed the lowest proficiency. Practitioners with a doctorate or equivalent degree were significantly more likely to report frequent engagement with medical literature than non-physicians ( p = 0.02).

CONCLUSION

There exists a significant disparity in scientific literacy between physician and nonphysician aesthetic medicine practitioners. This gap underscores the need for enhanced educational programs and continuous professional development to ensure safe and effective patient care in the evolving field of aesthetic medicine.

Needle Microcores: Can They Pose an Occlusive Threat with Nonparticulate Injections?

SUMMARY

The incidence of vascular occlusion injuries has risen substantially along with the increasing popularity of cosmetic injectables. Among these occurrences, instances of soft-tissue ischemic events following the injection of nonparticulate solutions, such as botulinum, represent an enigmatic etiology that has yet to be fully understood. One hypothesized mechanism of injury underlying these events relates to the accidental capture and intravascular ejection of needle microcores, defined as submillimeter tissue fragments trapped by the beveled lumen of a needle during conventional injections. To test this hypothesis, the authors conducted a cytologic evaluation of dermal remnants incidentally captured by 31-G tuberculin needles following repeated injections into postrhytidectomy skin fragments. Their findings revealed the presence of dermal tissue microcores ranging from 100 to 275 μm in diameter with an overall microcoring incidence of 0.7%. These findings confirm the ability of ultrafine needles, commonly used in botulinum injections, to produce tissue microcores that may serve as causative agents of vascular occlusion with nonparticulate solutions. Awareness of this mechanism of injury may be of benefit in the early recognition and management of these rare occurrences.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Injection-related Visual Compromise

The global market for hyaluronic acid (HA)-based dermal fillers has experienced substantial growth, providing patients with an effective nonsurgical cosmetic option. According to the global market report, the HA dermal fillers market size is expected to grow to $8.5 billion in 2027 at an annual growth rate (CAGR) of 8.9%. However, despite their popularity, HA injections are not free of complications. Vascular occlusion, particularly involving the central retinal artery, represents a significant risk. This case report presents a 60-year-old woman who presented with binocular vertical diplopia after HA filler injection in the right tear trough area. Upon evaluation, the patient exhibited right hypertropia, suggesting right inferior rectus paresis due to vascular injury of the infraorbital artery. Prompt management with hyaluronidase and oral steroids resulted in the resolution of double vision. This case highlights the importance of recognizing potential complications during HA filler injections and emphasizes the need for early intervention to minimize adverse effects.

Cosmetic Filler-Induced Vascular Occlusion: A Rising Threat Presenting to Emergency Departments

Vascular emergencies from cosmetic filler-induced vascular occlusion represent an iatrogenic etiology that poses a threat to patients, with sequelae that range from disfiguring skin necrosis to blindness and stroke. As cosmetic fillers continue to grow in popularity, the importance of early identification, triaging, and management of these rare but potentially disabling injuries has motivated efforts to educate the public and professional audiences. In this practice review article, we outline components of acute care pertaining to these injuries based on evolving practice guidelines and best evidence recommendations.

Histopathologic analysis of hyaluronic acid composite solution following intravascular injection: Variability and safety

BACKGROUND

Although a composite solution of non-crosslinked hyaluronic acid is generally considered safe, few studies have investigated its safety after intravascular injection.

METHODS

Male Sprague-Dawley rats were administered 0.05 mL of a non-crosslinked hyaluronic acid composite solution via intravascular injection into bilateral inferior epigastric arteries (IEA). Artery samples were obtained at multiple time points for histopathologic analysis. Bilateral abdominal flaps supplied by the IEA were lifted and the same dose of solution was injected into the artery, and flap survival was analyzed.

RESULTS

Histopathologic analysis showed that the non-crosslinked hyaluronic acid composite solution remained temporarily in the artery lumen following intravascular injection. With continuous blood flow, the filler gradually disintegrated and the artery became recanalized. At 24 h, no filler remained in the lumen. At 7 days after the filler was injected into the IEA feeding the flap, there was no significant difference between the experimental and control groups with respect to flap survival rate.

CONCLUSIONS

Non-crosslinked hyaluronic acid composite solution is relatively safe when a minimal volume is administered by intravascular injection. The filler will remain in the vessel for a short time, after which the vessel recanalizes.

Arterial Embolism After Facial Fat Grafting: A Systematic Literature Review

BACKGROUND

While autologous fat grafting of the face is considered a generally safe procedure, severe complications such as arterial embolism (AE) have been reported.

OBJECTIVE

To summarize data on injection-related visual compromise, stroke, and death caused by arterial embolism after facial fat transplantation.

MATERIALS AND METHODS

Plastic surgery societies were contacted for reports on AE after autologous facial fat injection. In addition, a systematic literature review was performed. Data extracted included study design, injection site/technique, symptoms, management, outcome, and etiology.

RESULTS

61 patients with a mean age of 33.56 ± 11.45 years were reported. Injections targeted the glabella or multiple facial regions (both n = 16/61, 26.2%) most commonly, followed by injections in the temples (n = 10/61, 16.4%) and the forehead (n = 9/61, 14.8%). The mean volume injected was 21.5 ± 21.5 ml. Visual symptoms were described most frequently (n = 24/58, 41.4%) followed by neurological symptoms (n = 20/58, 34.5%), or both (n = 13/58, 22.4%). Ophthalmic artery (OA, n = 26/60, 43.3%), anterior or middle cerebral artery (CA, n = 11/60, 18.3%) or both (n = 14/60, 23.3%) were most frequently occluded. Outcome analysis revealed permanent vision loss in all patients with OA occlusion (n = 26/26, 100%), neurological impairment in most patients with CA occlusion (n = 8/10, 80%), and vision loss in most patients suffering from both OA and CA occlusion (n = 7/11, 63.6%). Six patients died following embolisms.

CONCLUSIONS

AE causes severe complications such as blindness, stroke, and death. Due to a lack of high-quality data, no evidence-based treatment algorithms exist. To increase patient safety, a database collecting cases and complications should be established.

LEVEL OF EVIDENCE III

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 .

Purtscher-like retinopathy and paracentral acute middle maculopathy following breast filler injection

BACKGROUND

To report a rare case of pulmonary and ocular complications with visual loss due to bilateral Purtscher-like retinopathy and paracentral acute middle maculopathy (PAMM) following a hyaluronic acid (HA) filler injection to the breast. Systemic and visual recovery was attained following corticosteroid therapy.

CASE PRESENTATION

A 27-year-old lady presented with painless blurring of vision in both eyes for 2 weeks following hyaluronic acid breast filler injections by a non-medical practitioner. She was initially admitted to the medical ward for diffuse alveolar haemorrhage and altered sensorium. The presenting visual acuity was counting fingers in both eyes. Bilateral dilated fundus examination showed hyperaemic discs, concentric rim of retinal whitening around macula with patches of polygonal-shaped retinal whitening, generalised cotton-wool spots, tortuous veins, and flame-shaped haemorrhages. Spectral-domain optical coherence tomography (SD-OCT) macula revealed hyper-reflective bands at the inner nuclear layer (INL). Fluorescein angiography demonstrated hot discs, delayed arm-to-retina time, arterial filling, and arterio-venous transit time with staining of the vessels at the posterior pole. She was managed with a tapering dose of systemic corticosteroids. The visual acuity improved to 6/12 over 8 weeks with significant anatomical and functional improvement. Dilated fundus examination showed resolution of initial funduscopy findings. The hyper-reflective bands on the OCT had resolved with subsequent thinning of the INL and disorganisation of retinal inner layers.

CONCLUSION

Filler injections are in increasing demand and are frequently being performed by non-medical practitioners. Visual loss from non-facial HA fillers is rare. Inadvertent entry of HA into a blood vessel may potentially cause systemic and sight-threatening ocular complications. Good anatomical knowledge and proper injection technique are vital in preventing this unfortunate sequela. There are limited reports on successful visual recovery following various treatment approaches and we hope this case provides valuable insights.

Laser-Assisted and Device-Assisted Filler Delivery: A Histologic Evaluation

BACKGROUND

Lasers and devices are used to enhance transcutaneous delivery of fillers. However, little has been published on the histologic findings of this form of laser/device-assisted delivery to determine the optimal devices and fillers.

OBJECTIVE

To objectively evaluate the histological effects of laser-assisted and device-assisted filler delivery.

METHODS

Ex vivo human abdominoplasty skin samples were treated with fractional CO 2 laser (ECO 2 , 120 μm tip, 120 mJ), fractional radiofrequency microneedling (FRMN, Genius, 1.5 mm, 20 mJ/pin), and microneedling (2.0 mm). Immediately after poly- l -lactic acid (PLLA), hyaluronic acid gel, calcium hydroxylapatite, and black tissue marking dye were topically applied. After treatment, biopsies were collected for histologic evaluation.

RESULTS

Histology revealed that PLLA and black dye were found in greatest abundance, hyaluronic acid was found to a lesser extent, and calcium hydroxylapatite was least found within channels created by fractional CO 2 laser. Microneedling was effective only at delivering black dye, whereas FRMN failed to show significant channel formation or delivery of the studied products.

CONCLUSION

Among the devices and fillers studied, fractional CO 2 laser and PLLA proved to be the most effective combination for laser/device-assisted filler delivery. Neither microneedling nor FRMN was effective as devices to enhance filler delivery.

Clinical Manifestations and Prognosis of Embolism Caused by Filler Injection in Different Facial Regions

Background

Embolism is a serious complication after facial filling, with a usually poor prognosis of the symptoms after embolism. The authors systematically reviewed reported cases of facial vascular embolism, explored the relationship between the location and material used for facial filling and occurrence of vascular embolism, and assessed the prognosis of complications after vascular embolism.

Methods

This study provides a systematic review of published cases of vascular embolism after facial filling. A summary of the filling materials and filling sites for each case, the adverse reactions and embolized blood vessels, a recording of the time when each patient experienced adverse reactions and started treatment, and a presentation of their prognosis are provided.

Results

The frontal, eyebrow, and nose are common filling sites causing facial embolism. The main clinical manifestations after embolism were visual impairment, skin necrosis, and ptosis. The prognosis of visual impairment after embolization was poor, whereas skin necrosis and ptosis generally improved after treatment.

Conclusions

This article aimed to review the clinical manifestations, therapies, and prognosis of embolism after facial filling. A better understanding of these complications can help clinicians to detect the occurrence of complications as early as possible and give patients timely treatment.

Central Forehead Ischemic Skin Injury following Glabellar Botulinum: A Paradigm Microshift?

Vascular occlusion events have surged in incidence due to the increased popularity of cosmetic injectables. Ostensibly, treatments that involve nonparticulate solutions, such as botulinum, have traditionally been thought to carry no risk of vaso-occlusive complications. In this article, we report the first published instance of a suspected ischemic skin injury after botulinum injection to the glabella and surmise on the potential etiological mechanisms that may underlie these rare occurrences.

Multidose Hyaluronidase Administration as an Optimal Procedure to Degrade Resilient Hyaluronic Acid Soft Tissue Fillers

Minimally invasive hyaluronan (HA) tissue fillers are routinely employed to provide tissue projection and correct age-related skin depressions. HA fillers can advantageously be degraded by hyaluronidase (HAase) administration in case of adverse events. However, clear guidelines regarding the optimal dosage and mode of administration of HAase are missing, leaving a scientific gap for practitioners in their daily practice. In this study, we implemented a novel rheological procedure to rationally evaluate soft tissue filler degradability and optimize their degradation kinetics. TEOSYAL RHA^® filler degradation kinetics in contact with HAase was monitored in real-time by rheological time sweeps. Gels were shown to degrade as a function of enzymatic activity, HA concentration, and BDDE content, with a concomitant loss of their viscoelastic properties. We further demonstrated that repeated administration of small HAase doses improved HA degradation kinetics over large single doses. Mathematical analyses were developed to evaluate the degradation potential of an enzyme. Finally, we tuned the optimal time between injections and number of enzymatic units, maximizing degradation kinetics. In this study, we have established a scientific rationale for the degradation of HA fillers by multidose HAase administration that could serve as a basis for future clinical management of adverse events.