Intralesional hyaluronidase injection to relieve non-hyaluronic acid filler-induced vascular adverse events.

BACKGROUND: Vascular adverse events (VAEs) occurring during injections of soft-tissue fillers are still considered a challenging issue for both patients and practitioners. Hyaluronidase can dissolve hyaluronic acid (HA)-based soft-tissue fillers during a VAE. For VAEs induced by non-HA fillers, the absence of an "antidote" is regarded as exceptionally challenging. METHODS: This multicenter study describes a case series of three VAEs induced by non-HA fillers, for which ultrasound-guided hyaluronidase injections were incorporated into the treatment approach. RESULTS: Two cases of calcium hydroxylapatite and one case of poly-L-lactic acid-induced VAEs are described, all of which were resolved without necrosis or scarring using a treatment approach with ultrasound-guided hyaluronidase injections. CONCLUSIONS: Unlike the mechanical hypothesis, which assumes filler particles travel antegrade to block arterioles in a large skin area, we hypothesize vasoconstriction as the pivot in VAEs. Filler injection-induced spasms could lead to long-lasting vasoconstriction of the perforator arteries stemming from the central facial arteries. Our results underscore that perforasome vasoconstriction might be the leading cause of the ischemia and subsequent necrosis in VAEs and that relaxation of these perforasomes, rather than dissolving the filler material, resolves the clinical symptoms associated with VAEs.

Improved brachial skin hydration and appearance with hyperdiluted calcium hydroxylapatite.

INTRODUCTION: The search for minimally invasive treatments for areas not covered by clothing, such as the arms, has increased, particularly to combat flaccidity resulting from factors such as aging and weight loss. This study evaluated the efficacy of calcium hydroxyapatite (CaHA), an injectable biostimulator, in improving flaccidity and hydration of the skin of the arms. MATERIALS AND METHODS: Six women between 40 and 50 years old with visible signs of brachial flaccidity were selected. Calcium hydroxyapatite was injected into the arms in a 1:4 dilution (1.5 mL per side), with subjective evaluation based on the GAIS score and objective hydration analysis using corneometry. RESULTS: After a single application of CaHA, there was a significant increase in skin hydration (12.2%), objectively assessed by corneometry. Patient and physician satisfaction was high, evidenced by visible improvements in photographs and by the GAIS score. No significant adverse events were reported, demonstrating the safety of the procedure. DISCUSSION: Our clinical observations confirm the ability of CaHA to visibly improve arm flaccidity. In addition, hydration measures support previous histological studies demonstrating increases in dermal proteoglycans. Compared to other studies, the increase in skin hydration with CaHA was similar to those obtained with hyaluronic acid, suggesting comparable results with a more comfortable and less invasive technique. CONCLUSION: This study demonstrates the efficacy of CaHA in improving hydration of brachial skin after a single treatment. Despite the limitations of the sample size, the research contributes to the medical literature, highlighting the utility of the 3 mL CaHA presentation for brachial treatment with objective results in skin hydration.

A morphological analysis of calcium hydroxylapatite and poly-l-lactic acid biostimulator particles.

Injectable fillers, pivotal in aesthetic medicine, have evolved significantly with recent trends favoring biostimulators like calcium hydroxylapatite (CaHA-CMC; Radiesse, Merz Aesthetics, Raleigh, NC) and poly-l-lactic acid (PLLA; Sculptra Aesthetics, Galderma, Dallas, TX). This study aims to compare the particle morphology of these two injectables and examine its potential clinical implications. Utilizing advanced light and scanning electron microscopy techniques, the physical characteristics of CaHA-CMC and PLLA particles were analyzed, including shape, size, circularity, roundness, aspect ratio, and quantity of phagocytosable particles. The findings reveal several morphological contrasts: CaHA-CMC particles exhibited a smooth, homogenous, spherical morphology with diameters predominantly ranging between 20 and 45 µm, while PLLA particles varied considerably in shape and size, appearing as micro flakes ranging from 2 to 150 µm in major axis length. The circularity and roundness of CaHA-CMC particles were significantly higher compared to PLLA, indicating a more uniform shape. Aspect ratio analysis further underscored these differences, with CaHA-CMC particles showing a closer resemblance to circles, unlike the more oblong PLLA particles. Quantification of the phagocytosable content of both injectables revealed a higher percentage of phagocytosable particles in PLLA. These morphological distinctions may influence the tissue response to each treatment. CaHA-CMC's uniform, spherical particles may result in reduced inflammatory cell recruitment, whereas PLLA's heterogeneous particle morphology may evoke a more pronounced inflammatory response.

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.

Safety and Efficacy of Diluted Calcium Hydroxylapatite for the Treatment of Cellulite Dimpling on the Buttocks: Results from an Open-Label, Investigator-Initiated, Single-Center, Prospective Clinical Study.

BACKGROUND: Cellulite is a condition characterized by dimpling and contour irregularities in the gluteal and thigh regions, affecting an estimated 80-98% of postpubertal women. Innovative treatments for cellulite dimpling in the buttocks have gained popularity in recent years, seeking new solutions for a historically challenging condition. In this open-label, investigator-initiated, single-center, prospective clinical study, the authors sought to evaluate the safety and efficacy of diluted calcium hydroxylapatite (CaHA; Radiesse®, Merz Aesthetics, Raleigh, NC) for the treatment of cellulite dimpling in the buttocks of adult women. METHODS: Subjects underwent three treatment sessions, receiving a total of 12 syringes of 1:1 diluted CaHA administered using a cannula-based subcision technique. Endpoints included the cellulite severity scale (CSS), the global aesthetic improvement scale (GAIS), subject satisfaction measured on a 5-point scale, and three-dimensional imaging analysis via the Quantificare 3D Track®. RESULTS: Twenty-four subjects completed the study (mean age, 35 years; mean BMI, 26.88 kg/m2; mean body fat percentage, 31.29%), and no serious complications were reported. Quantitative analysis at week 14 revealed a mean reduction of 54.0% in the number of visible dimples and 50.09% in dimple depth compared to baseline. The mean CSS score decreased by 4.29 points, representing a 43.92% improvement in cellulite severity from baseline (p < 0.0001). Both physician-assessed and subject-assessed GAIS ratings also demonstrated significant improvement, with 91.6% of subjects rating their cellulite appearance as "improved" or greater. CONCLUSION: The results of this study support the safety and efficacy of diluted CaHA for treating cellulite dimpling in adult women. LEVEL OF EVIDENCE II: 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 . CLINICAL TRIALS REGISTRATION: This study is registered with clinicaltrials.gov (ID: NCT05885035) and can be found at this link: https://clinicaltrials.gov/study/NCT05885035 .

Starting Point for Protocols on the Use of Hyperdiluted Calcium Hydroxylapatite (Radiesse®) for Optimizing Age-Related Biostimulation and Rejuvenation of Face, Neck, Décolletage and Hands: A Case Series Report.

Radiesse® is a dermal filler made of calcium hydroxylapatite, a natural component of the human body, which, in diluted and hyperdiluted forms, promotes, unlike other fillers, neocollagenesis, neoelastinogenesis, fibroblast proliferation, and angiogenesis, leading to a long-term improved skin quality, elasticity, tightening, and firmness. This case series examined the use of Radiesse® (Merz, Frankfurt, Germany) for skin rejuvenation and regeneration through a long-lasting action of collagen biostimulation. The report explored for the first time the use of different dilution ratios of Radiesse® in 50 patients of varying ages and skin needs. By combining microboluses, tunneling, and/or fanning techniques, Radiesse® was superficially injected in different body regions, including the full-face, neck, décolletage, and hands. The treatment was effective in improving skin thickness, laxity, and wrinkles in 95% of 30-40 year-olds, 80% of 40-60 year-olds, and 70% of >60 year-olds, with an average improvement of 81.6% for the general population. The treatment was well-tolerated with no significant adverse effects reported. The report also describes specific cases and includes pictures comparing the baseline condition to the changes obtained after different months and Radiesse® sessions. The patients reported a clear improvement in skin firmness and brightness, as well as a visible improvement in wrinkles' appearance. This report found that diluting and hyperdiluting Radiesse® with flexible dilution ratios favoured a treatment's individualization, providing improved skin quality, elasticity, tightening, and firmness, without volume augmentation. In conclusion, it highlights the versatility and flexibility of Radiesse® and emphasizes its efficacy and safety in skin rejuvenation and regeneration.

Calcinosis cutis / Calcinosis cutis

Caso clínico: presentamos el caso de una mujer de 48 años con dolor en senos maxilares y zonas temporales, en la que se apreciaron placas cálcicas subcutáneas faciales al realizar una tomografía axial computarizada (TC). La exploración física y los datos del laboratorio fueron normales. Reinterrogando a la paciente, comentó que un año antes se le había administrado un producto de relleno facial que contiene hidroxiapatita cálcica (CaHA) (Radiesse®). Discusión: las microesferas de CaHA son radiopacas por lo que pueden observarse en las radiografías convencionales, y sobre todo en la TC. Las características de las imágenes, habitualmente bilaterales, separadas del hueso, junto con el antecedente de inyección previa de este material, debe orientar al clínico para reconocer este hallazgo y diferenciarlo de otras condiciones patológicas. Dada la popularidad que ha adquirido esta técnica de rejuvenecimiento facial, conviene que los clínicos conozcamos las características de las imágenes producidas por el depósito de esta sustancia. (AU)

Case report: we report the case of a 48-year-old woman with pain in the maxillary sinuses and temporal areas. The presence of subcutaneous facial calcific plaques was confirmed in computed tomography (CT). Both the physical examination and the lab test results were within normal limits. Upon further questioning, the patient mentioned that she had been administered a facial filler product containing calcium hydroxyapatite (CaHA) (Radiesse®) the year before. Discussion: CaHA microspheres are radiopaque, making them visible through conventional x-rays, especially CT scans. The characteristic imaging features, typically bilateral and separate from the bone, along with the history of previous injection of this material, should help the clinician recognize this finding and isolate it from other conditions and diseases. Because of the popularity of this facial rejuvenation technique, clinicians should be familiar with the imaging characteristics associated with the deposition of this substance. (AU)

Bilateral Gluteal Augmentation With Hyperdilute Calcium Hydroxylapatite Microspheres Performed Using the Bella Vida Instant Brazilian Butt Lift (BBL)™.

For decades, aesthetic medical procedures have sought to improve patient appearance, comfort, and self-confidence. In more recent years, a growing interest in body contouring cosmetic procedures has emerged, in large part due to increased transparency in procedures and improved outcomes with minimally invasive procedures. Notably, several biostimulatory fillers have emerged as a suitable treatment modality due to their relatively low cost, low pain, short downtime, high tunability, and sustained biostimulatory effect. One volumizing biostimulatory filler, Radiesse® (Merz Aesthetics, Frankfurt, Germany), consists of calcium hydroxylapatite microspheres suspended in a carboxymethyl cellulose gel. When injected, Radiesse immediately volumizes the injection site and initiates neocollagenesis and neoelastogenesis. One technique, the Bella Vida Instant Brazilian Butt Lift (BBL)™, is a fast, safe, and minimally invasive alternative to surgical gluteal augmentation that accomplishes morphological remodeling, increases volumization, and improves shape and patient satisfaction. This technical report provides the clinical basis, materials, and methods for implementing the Bella Vida Instant BBL™ in aesthetic practices.

Combining Calcium Hydroxylapatite and Hyaluronic Acid Fillers for Aesthetic Indications: Efficacy of an Innovative Hybrid Filler.

BACKGROUND: Limited data are available describing effectiveness of combining the use of calcium hydroxylapatite (CaHA) and hyaluronic acid (HA). METHODS: The authors performed a retrospective chart review of patients injected with a premixed combination of CaHA and a cohesive polydensified matrix (CPM®) HA (CaHA:CPM-HA ) in the authors' aesthetic practices. The midface and lower face were injected. Patients' records were evaluated, and treatment results were scored using the Merz Aesthetics Scale for the jawline® (clinician rated, CR-MASJ). Adverse events were recorded. RESULTS: A total of 41 patients were included, all females with a mean age of 47.5 years (range 21-63 years). The mean CR-MASJ score improved from 2.12 at baseline to 0.68 at t = 3 months (SD = 0.69, 95% CI 1.28-1.60) and 1.27 at t = 12 months (SD = 0.74, 95% CI 0.43-0.74). 100% of the subjects had experienced a ≥1-point improvement in CR-MASJ score at t = 3 months, versus 85% at t = 12 months. No adverse events were reported. CONCLUSION: The results of this study support the volumizing and lifting potential of the hybrid mix CaHA:CPM-HA for treatment of cheeks and jawline. 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 .

Identification of a suitable layer for injecting calcium hydroxylapatite fillers in the hands.

BACKGROUND: Hand rejuvenation has become increasingly popular in esthetic medicine. Hand rejuvenation with injectables remains challenging, and there are no established practice guidelines. The calcium hydroxylapatite (CaHA) filler injection is currently one of the most common procedures. This study aimed to identify the layer of the hand dorsum that is lifted by skin pinching and to identify the layer where an injectable filler would be placed based on the anatomical study and ultrasound findings. METHODS: The anatomic layers of the cadaveric hands were examined using the skin pinching method. Anatomic dissections and histological examinations were performed on four fixed and five fresh cadaveric hands to reveal the anatomical layers in which the CaHA filler was administered. Furthermore, 20 patients were treated with the CaHA filler, and the Doppler ultrasound was used to reveal the proper anatomical layers for filler placement. RESULTS: The study of the cadaveric hands showed that skin pinching can ensure safe entry points and can guide the cannula into safe planes without compromising the large superficial veins. A filler injection with skin pinching in cadaveric hands demonstrated that the filler was introduced primarily in the dorsal intermediate lamina where the veins are present. This was further confirmed by ultrasound findings. CONCLUSION: The dorsal intermediate lamina, which has the veins is a relatively loose structure, and the cannula was moved along this space. When the layer is stretched by skin pinching, the veins run underneath. The dorsal intermediate lamina is the appropriate layer to inject the filler.

Ophthalmic Artery Occlusion and Subsequent Retinal Fibrosis From a Calcium Hydroxylapatite Filler Injection.

PURPOSE: We report a case of otherwise healthy 48-year-old woman presenting with acute vision loss after injection of a soft tissue filler injection in the glabellar region with calcium hydroxylapatite microspheres (Radiesse®) with 9 months of follow-up. OBSERVATIONS: Fundus photographs and spectral domain optical coherence tomography (SD-OCT) were obtained at presentation, 4 months of follow-up, and 9 months of follow-up. Acutely, the retina was characterized by significant pallor and thickening but evolved into diffuse retinal fibrosis and atrophy. The patient was no light perception at presentation, and did not recover any visual function. CONCLUSIONS AND IMPORTANCE: Few case reports have described calcium hydroxylapatite filler injections leading to orbital and ocular complications. This is the first case report illustrating dense fibrotic and atrophic retinal changes on both fundus photography, fluorescein angiography, and SD-OCT. While various facial fillers have been reported to have serious ocular consequences, we illustrate the acute and subsequent sequelae of an ophthalmic artery occlusion from calcium hydroxylapatite microspheres (Radiesse®).

Injection technique in neurotoxins and fillers: Planning and basic technique.

Cosmetic dermatologic surgery has evolved to be a minimally invasive field that addresses patient concerns with a multimodal approach while minimizing adverse events and downtime. Within the armamentarium of dermatologic surgery, injections of soft tissue augmentation materials and neuromodulators are key tools for recontouring the aging face. Treatment of the individual patient is preceded by a comprehensive consultation that elicits patient concerns and preferences. A treatment plan is collaboratively developed to correct relevant deficits and retreat as appropriate to maintain the correction. The goal of volumization with fillers is to recreate atrophic subcutis and dermis, thereby filling the deflated face and returning it to a more youthful contour. Neurotoxins can help minimize the emergence of static wrinkles and selectively recontour the face. Treatment techniques for both filler and neurotoxin injections are customized for particular patient needs and are based on the type of deficit and the anatomic location.

Injection technique in neurotoxins and fillers: Indications, products, and outcomes.

Injectable fillers and neuromodulators are used for a range of indications pertaining to the correction of facial aging and disfigurement. Fillers can correct soft tissue loss, depressed scars, and atrophy or asymmetry induced by systemic or local disease. Neuromodulators correct muscle-mediated skin creases, reshape the face, and address right-left functional asymmetry. Among the prepackaged injectable fillers approved by the US Food and Drug administration are hyaluronic acid derivatives, calcium hydroxylapatite, and poly-L-lactic acid; neuromodulators include three types of botulinum toxin type A and one type of type B. Adverse events associated with injections are typically mild, easily managed injection pain, followed by redness, swelling, and bruising. Asymmetry, nodules, ptosis, and intravascular occlusion are less common. Filler and toxin injections are part of a complete treatment plan. Reinjection is typically required to maintain the clinical effect, and combination treatment with laser and energy devices can enhance the aggregate effect.

Alopecia with foreign body granulomas induced by Radiesse injection: A case report.

Radiesse is a soft tissue filler which has been widely used for cosmetic enhancement. The safety of Radiesse has been thoroughly investigated via numerous studies. A late-onset complication of Radiesse injection consists of foreign body granulomas, with only three case reports in over 10 years of clinical use. Herein, we describe the case of a patient who experienced alopecia with foreign body granulomas at the injection region one month after receiving a Radiesse injection. To our knowledge, this is the first report in the English literature of alopecia as an adverse event associated with Radiesse injection. The present case reminded physicians to evaluate more cautiously the necessity of injecting filler into hair-bearing area for lifting purpose. This procedure may cause foreign body granulomatous reaction, which may result in hair loss at the injection region.

Calcium hydroxylapatite treatment of human skin: evidence of collagen turnover through picrosirius red staining and circularly polarized microscopy.

BACKGROUND: Calcium hydroxylapatite (CaHA, Radiesse®) is a biocompatible, injectable filler for facial soft-tissue augmentation that provides volume to tissues, followed by a process of neocollagenesis for improved skin quality. OBJECTIVE: To examine the effects of CaHA treatment on the molecular organization of collagen using a combination of picrosirius red staining and circularly polarized light microscopy. METHODS: Five subjects received subdermal injection of 0.3 mL of CaHA in tissues scheduled for removal during abdominoplasty 2 months later. Tissue specimens from the CaHA injection site and a control untreated area were obtained from excised skin at the time of surgery. Processed tissue sections were stained with picrosirius red solution 0.1% and visualized under circularly polarized light microscopy for identification of thick mature (type I) and thin newly formed (type III) collagen fibers. Pixel signals from both the control and CaHA-treated areas were extracted from the images, and morphometric computerized hue analysis was performed to provide a quantitative evaluation of mature and newly formed collagen fibers. RESULTS: Under picrosirius red staining and circularly polarized light microscopy, green/yellow areas (thin newly formed collagen type III) were visible among the collagen fibers in tissue sections from the area of CaHA injection. In contrast, the majority of the collagen fibers appeared red (thick mature collagen type I) in control tissues. Morphometric analysis confirmed that, following CaHA treatment, the proportion of fibers represented by thin newly formed collagen type III increased significantly (p<0.01) in comparison with the proportion of thick mature collagen type I fibers. In contrast, collagen content of control tissues consisted almost exclusively of thick mature collagen type I fibers. CONCLUSION: The use of picrosirius red staining and circularly polarized light microscopy provides evidence that subdermal injection of CaHA stimulates the formation of new collagen and dermal remodeling.

Orbital Volume Augmentation with Calcium Hydroxyapatite Filler in Anophthalmic Enophthalmos.

PURPOSE: To report the long-term results of orbital volume augmentation using calcium hydroxyapatite filler injections in patients with anophthalmic sockets. METHODS: Twelve eligible patients with post-enucleation socket syndrome (PESS) and small orbital volumes were included in our study. In this investigation, 1.5 mL injectable calcium hydroxyapatite (Radiesse) was utilized in an off-label application under local anesthesia. We evaluated the effect of orbital volume augmentation for correction of enophthalmos. RESULTS: Five women and seven men with a mean age of 35 years (range, 21-72 years) were included in the study. The mean follow-up was 19.5 months (range, 16-27 months). Enophthalmos and deep superior sulcus were reduced in all patients during all follow-up visits postoperatively. The mean improvement of enophthalmos was 2.58 mm (range, 1-5 mm) and the improvement in deformity grading of superior sulcus was 0.83 (range, 0-4 grade). The mean marginal reflex distance increased by 0.6 mm (range of -1 to 3 mm). Complications included increase in ptosis in two cases and extrusion of the filler accompanied by discoloration of the skin in one case. CONCLUSION: The use of injectable calcium hydroxyapatite for orbital volume restoration in anophthalmic sockets is a simple, fast, and minimally invasive method with considerable long-term effects and low complications.

Calcium hydroxylapatite: A review on safety and complications.

BACKGROUND: Radiesse® , or calcium hydroxylapatite (CaHA), is a biodegradable, biostimulatory soft tissue filler suitable for deeper folds and wrinkles. In the literature, good results have been documented with the use of CaHA and patient satisfaction scores are high. This study reviews the current literature on safety and complications of CaHA. METHODS: A literature search in MEDLINE/PubMed electronic database was conducted. A total of 21 articles were included and screened for reports of adverse events (AEs). RESULTS: Twenty-one peer-reviewed articles, published between 2004 and 2015, were included. A total of 5081 treatments with CaHA were performed on 2779 patients. A total of 173 (3%) AEs were reported. The assessed types of AEs consisted of nodules (n=166, 96%), persistent inflammation/swelling (n=4, 2%), persistent erythema (n=2, 1%), and overcorrection (n=1, 1%). CONCLUSION: Based on the results in this study, CaHA appears to have a good safety profile. Nodules are by far the most common AE. Of the reported nodules, 49% occurred in "dynamic" areas currently known for having a higher tendency for nodules. Several treatment approaches exist for managing CaHA nodules; however, in most cases, CaHA nodules are not visible and resolve without intervention.

The use of injectable calcium hydroxylapatite in the surgically pretreated larynx with glottal insufficiency.

OBJECTIVES/HYPOTHESIS: To evaluate the efficacy of vocal fold (VF) augmentation with calcium hydroxylapatite (CaHA) microspheres in the surgically pretreated larynx with glottal insufficiency. STUDY DESIGN: Prospective clinical pilot study. METHODS: After several prior reconstructive attempts (following tumor resection, VF paralysis, in sulcus vocalis, and VF scarring), CaHA was injected under general anaesthesia using a transoral microlaryngoscopic approach in 10 patients with residual glottal insufficiency ≤1.5 mm. The postinterventional result was assessed after 1 day, and 1 and 3 months. Evaluation of augmentation comprised intraoperative video/photo documentation, pre-/postoperative videolaryngostroboscopy, as well as established subjective and objective voice function diagnostics (Grade, Roughness, Breathiness [GRB] Scale; Voice Handicap Index; voice range profile; and acoustic-aerodynamic analysis). RESULTS: In the pretreated VF with no or minimal lamina propria remaining, the exact placement of CaHA was not possible due to unpredictable propagation into the scarred tissue. The results showed an insufficient postoperative augmentation. Accordingly, the voice function did not improve. However, a significant increase of the vocal range from 6.2 ± 3.2 to 8.7 ± 3.9 semitones was observed in the speaking voice profile (P =.02). All other acoustic and aerodynamic parameters remained on the whole unchanged; the slight differences between pre- and postoperative findings were not significant. CONCLUSIONS: The application of CaHA in the surgically pretreated scarred larynx is not reliable to achieve a sufficient glottal closure and a satisfactory improvement of voice. Though CaHA is a welcome addition to our armamentarium against glottal insufficiency, the suitability for augmentation of scar tissue in the larynx must be considered carefully in each individual case. LEVEL OF EVIDENCE: 4 Laryngoscope, 127:1125-1130, 2017.

Evaluation of Heating and Shearing on the Viscoelastic Properties of Calcium Hydroxyapatite Used in Injection Laryngoplasty.

OBJECTIVE: To compare the viscoelastic properties of calcium hydroxyapatite (CaHA) to carboxymethylcellulose (CMC) injectables used for injection laryngoplasty and determine if they are affected by heating and shearing. STUDY DESIGN: Experimental. SETTING: University laboratory. SUBJECTS AND METHODS: Vocal fold injection laryngoplasty with CaHA is oftentimes challenging due to the amount of pressure necessary to push the injectate through a needle. Anecdotal techniques, such as heating the product, have been suggested to facilitate injection. The viscoelastic properties of CaHA and CMC were measured with a rheometer. The effects of heating and shearing on sample viscoelasticity were recorded. RESULTS: CaHA was 9.5 times more viscous than CMC (43,100 vs 4540 Pa·s). Heating temporarily decreased the viscosity of CaHA by 32%. However, it also caused the viscosity to subsequently increase after time. Shearing of CaHA reduced its viscosity by 26%. Heating and shearing together temporarily reduced the viscosity of CaHA by 52%. CONCLUSION: A combination of heating and shearing had a more profound effect than heating or shearing alone on the viscosity of CaHA, potentially making it easier to inject temporarily. Long-term and in vivo studies are required to further analyze the effect of heating and shearing on CaHA injectables.