Illustrated Manual of Injectable Fillers

Neil S. Sadick, Neil S. Sadick

• Editorial: CRC Press
• Año: 2020
• ISBN:
  9781351740081
• Edición: 2
• Categoría: Medizin
• Categoría: Medizinische Theorie, Praxis & Referenz

This practical text clearly evaluates the uses, limitations, and compositions of the growing variety of available fillers involved in face and body rejuvenation. It includes detailed techniques for facial analysis and diagnosis of aging conditions to help provide patients with safe, reliable, and aesthetically pleasing results, including preventing and properly treating potential complications of filler usage. With new chapters on limb and torso injections and combination treatments, this new edition will be an invaluable resource for all aesthetic practitioners.

1

Introduction to Structural Volumetric Rejuvenation

Neil S. Sadick

Cosmetic Surgery Trends

Non-invasive and minimally invasive procedures have rapidly changed the face of aesthetic medicine. Cannulas, needles, and syringes have replaced the scalpel, and lunchtime treatments have eradicated the need to take time off work for recovery. There is always momentum in the field, and clinicians are constantly testing and developing new strategies to offer to their aesthetic patients. Because men and women from every culture, age group, and ethnicity seek aesthetic treatments, intimate knowledge of anatomical differences between genders and across cultures, together with the ability to adapt to and adopt the ever-changing armamentarium of clinical tools is an absolute necessity.

As opposed to past trends, where an ironed-out look was sought after, today there has been a shift in the perception of what constitutes a youthful appearance. The new movement has been about conservative approaches that deal with the underlying loss of soft tissue to achieve a plumper, naturally less wrinkled, more three-dimensional appearance. This shift in the perception of what constitutes a “youthful visage,” combined with patient demand for minimally invasive procedures, has led to a major expansion in the field of soft tissue augmentation.

The facial aging process reflects an interplay of genetic, anatomic, chronologic, and environmental factors. It is characterized by thinning of the epidermis and subcutaneous fat layers, musculature atrophy, and a degree of bone resorption. In addition, a progressive loss of elastic fibers and collagen and weakening of underlying muscles contribute to the wrinkling process. Age associated changes can create shadows and hollows where they did not exist before. The aged face has prominent rhytids in the glabella, forehead, nasolabial folds (NLFs), and perioral areas. Today, dermatologic surgeons can approach these conditions of atrophic aging with autologous fat, or a variety of new-generation volumetric fillers.

Volumetric structural rejuvenation offers an excellent option for the treatment of facial aging, wrinkling, and contour defects. It is a preferred alternative to major surgery for patients seeking safe, minimally invasive, and affordable means of maintaining a youthful appearance. It is imperative however for the physician to have a thorough knowledge of all the available products and their properties. This knowledge will enable optimal pairing of facial filling techniques with specific concerns and consequent maximal efficacy and patient satisfaction.

Evolution of the Field

Historically, significant volume enhancement has been available through the surgical use of alloplastic implants. The exact origin of maxillofacial prosthetics is difficult to identify but major work in the 1930s provided the initiative for maxillofacial, dental, and plastic surgeons to work together for the betterment of focally injured patients. Today, the techniques that have evolved from those early trials have become safe and applicable in situations where even minimal deformity is present.

Transferring fat from one area of the body to another has revolutionized the trend of rejuvenation by volume restoration and it can be said that fat was the first available filler. There has been interest in fat transfer since the inception of whole fat grafts in the 1890s and injectable fat grafts in the 1920s. From then on, interest waned until the 1980s when interest once again boomed in the plastic surgery community. The rising popularity of this procedure has paralleled the development and popularity of liposuction for body contouring.

Autologous fat is plentiful and readily accessible once the harvesting technique is mastered. The technique is intended to preserve the delicate structure of adipocytes and provide a robust blood supply on which fat cells are extremely dependent. Fat provides excellent volumetric filling and the possibility of long-term results exceeding that of resorbable fillers. Patients’ satisfaction with fat is high and many prefer using their own autologous fat rather than synthetic fillers. Autologous fat can also offer benefits to the skin quality, improving acne, scarring, and providing a healthy luster. Whether this phenomenon is due to nutrients in the fat cells or “stem cell” characteristics, as has been proposed, is purely theoretical.

Some practitioners believe that fat transfers represent one of the most significant rejuvenation advances of the decade. Volumetric facial rejuvenation is excellent for the forehead, eyes, cheeks, chin, myelolabial lines, lips, marionette lines, and geniomandibular grooves. In the body, large-volume fat transfers can be used in the buttocks, breasts, calves, and for posttraumatic or iatrogenic liposuction defects. Ongoing interest in fat transfer and constant reassessment of clinical results will lead to further improvements in the procedure of fat transfer for soft tissue volumization and augmentation.

Injectable Fillers

The practice of using injectable fillers for soft tissue augmentation has a long and well described history. Today it is a crucial tool in the armamentarium of facial volumization.

Over the past decade, the use of injectable products in cosmetic dermatology has increased rapidly to become, together with neurotoxins, the most popular cosmetic procedure performed in physicians’ offices. Over the past few years, the search for an ideal filling agent has led to a plethora of available materials for facial rejuvenation. The ideal filler substance would be nonallergic, noncarcinogenic, nonteratogenic, durable, reproducible, stable, and affordable, and would cause minimal adverse events. Arguably, for some the ideal filler will be permanent and for others resorbable, depending on the patient’s prior experiences and the physician’s expertise. Although a filling material that satisfies all of the above criteria is yet to be found, there are numerous compounds that fall just short of doing so and are safely and easily administered in the office setting. The choice of filling substance depends on the depth of the target to be treated as well as various patient factors. It is important for the injector to be judicious, always informing patients of the risks and benefits of treatment and advocating appropriate test doses, if necessary, to avoid or minimize potential adverse events.

In the 1980s, the use of bovine collagen for cosmetic purposes started a new era of soft tissue augmentation. Over the past 5 years alone, the number of approved facial fillers in the US and abroad has grown rapidly. To date, the most widely used fillers fall into three major categories: nonpermanent, permanent, and semipermanent. Nonpermanent fillers produce short-lived results and eventually undergo resorption. Fillers of this type will require repeated injections for long-term results. Semipermanent fillers typically last longer than most nonpermanent fillers but can be expected to experience some resorption as well. Only permanent fillers can be expected to produce long-term results with a single injection.

Short-Term Fillers

Collagens

Collagen is a major component of human connective tissues such as bone, cartilage, skin, and vasculature. The injectable forms consist of varying concentrations of purified bovine, porcine, or human collagen. Bovine collagen was the first US Food and Drug Administration (FDA)–approved facial filler in 1981 and was harvested from an isolated US herd. One major disadvantage of bovine collagens (Zyderm, Zyplast) is their potential for immunogenicity and mandatory skin testing. Improving on the issue of allergic reactions are human (CosmoDerm, CosmoPlast) and porcine (Evolence) collagens. At the time of this writing, all of these fillers have been removed by the manufacturer from the US market; however, the potential remains for a porcine filler to be reintroduced. All collagen fillers are biodegradable and resorbable with results lasting less than 1 year. Slowing of collagen resorption (prolonged filler effect) is accomplished by crosslinking the collagen with moieties such as glutaraldehyde or ribose. Rapid degradation is not necessarily a drawback to collagen products; indeed, it is an asset under some aesthetic requirements. Collagens are best suited for superficial correction and are injected into the dermal plane. Rapid polymerizing collagen (RPC Pure-Collagen, EternoGen) is a new iteration of collagen that has been evaluated in US and European clinical trials. It consists of pure type I collagen molecules (un-crosslinked, sterile, non-pyrogenic, porcine derived), ethylenediaminetetraacetic acid (chelating and antimicrobial agent), and mannitol, an antioxidant to reduce free radical activity from the treatment site.

Hyaluronic Acid

Hyaluronic acid (HA) fillers are particularly popular because they have a low potential for allergic reaction and require no skin testing. Although they are not permanent, most of these agents have a significant length of duration. As of the start of 2017, there are 14 US FDA-approved HA fillers: Restylane (-L, Lyft, Refyne, Defyne, Silk), Juvederm (Ultra, Ultra XC, Plus, Plus XC, Voluma, Voluma XC, Vollure XC, Volbella XC), and Belotero Balance. At the time of publication a new HA filler, Teosyal (Teoxane), that earned US FDA approval in late 2017 is expected to be available in the US from early 2020.

HA is a naturally occurring glycosaminoglycan that composes the extracellular matrix of connective tissues. In the skin, it provides structure and volume while also maintaining and attracting moisture. As the skin ages, the amount of HA decreases and correlates with the formation of rhytids. Clinically, the injection of HA into the skin replenishes volume and revitalizes the skin’s appearance. Most HAs on the market are non-animal-stabilized HAs and are manufactured by the fermentation of Streptococcus equi bacterium. Most of the products differ in the total HA concentration and degree of crosslinked material. The total HA concentration refers to the measure of insoluble HA and soluble HA in a product. The soluble of liquid form of HA is absorbed very quickly and is added to some products to improve lubrication and flow through the needle. The insoluble gel portion that persists in the skin after injection contributes to the clinical effect. All of the currently available HA fillers are indicated by the FDA for injection into the mid to deep dermis for the correction of either moderate to severe facial wrinkles and folds, specifically NLFs, or in the lips. However, HA products are routinely used for off-label indications.

Intermediate to Long-Term Fillers

Calcium Hydroxylapatite

Calcium hydroxylapatite (CaHA), long used as a bone replacement, lends itself well to soft tissue augmentation. Its high density and low solubility provide a long-term effect with minimal immune sensitivity. Radiesse™ is the only FDA-approved CaHA dermal filler. It is a viscous gel, composed of carboxymethylcellulose, glycerine, and purified water, within which 25–45 µm spherical particles of CaHA are suspended. Radiesse is considered a medium- to long-term volumizer with duration of effect being reported to last over 12 months. Additionally this filler has been found suitable for diverse locations. In addition to volumizing the cheeks and NLFs, Radiesse is utilized for nose and chin augmentation as a panfacial volumizer and contouring agent. Radiesse was approved for usage in the dorsum of the hands in 2015.

Polycaprolactone

Polycaprolactone (PCL), presently in phase 3 trials, is demonstrating to be a much stronger biostimulatory filler than CaHA. The collagen produced by PCL is more stable, so PCL lasts longer than CaHA. The product called Ellansé comes in four types, S, M, L, and E, which last 1, 1.5, 3, and 4 or more years, respectively.

Poly-L-Lactic Acid

Poly-L-lactic acid (PLLA) is a synthetic material used in resorbable sutures, plates, and screws. PLLA for injection is available as Sculptra, a powered form of PLLA in microspheres of 40 to 63 µm in diameter, which must be reconstituted with sterile water prior to injection. PLLA is categorized as a bioactive filler due to its ability to stimulate neocollagenesis. PLLA was initially FDA approved for HIV lipoatrophy correction but was frequently used off-label for other cosmetic concerns. In July 2009, Sculptra was approved for aesthetic indications by the FDA. It is primarily utilized for diffuse global correction rather than individual rhytids and often requires multiple sessions for desired results. Correction is not immediate and requires 3–6 months as fibroblasts are stimulated to produce new collagen and dermal remodeling occurs. In addition to volumization, PLLA was recently shown to improve skin quality.

Permanent Fillers

Currently only one filler, Bellafill (previously ArteFill), is FDA approved for permanent correction. Bellafill is composed of polymethyl methacrylate microspheres in a bovine collagen carrier. The nondegradable microspheres serve to stimulate fibroblast activity and connective tissue ingrowth giving this filler a biostimulatory property. The end result is a biologically stable matrix that creates a durable, long-lasting cosmetic enhancement. An essential key to successful Bellafill use is a conservative approach with avoidance of overcorrection. The FDA approved the use of Bellafill for correction of NLFs in 2005 and for the correction of moderate to severe, atrophic, distensible facial acne scars on the cheek in 2015 for patients over the age of 21 years.

Other Considerations

Although injectable fillers can offer an efficacious alternative to surgery, they also have their limitations. It is important for the plastic surgeon to recognize specific circumstances that may be best managed with an alternative to fillers, including superficial contour defects too shallow for fillers; areas with significant skin laxity in which filler injection may result in lumpiness; and deep defects or folds in areas of dynamic movement, which may result in filler dislodgement or visible filler implants.

Appropriate and complete training is critical for success with all fillers. Indeed training is often a regulatory requirement associated with treatment. Choosing a dermal filler for a particular defect is perhaps more an art than science, with few hard and fast rules. Most products have been studied only in the NLFs, but are used in many other applications; thus experience remains the best teacher. Table 1.1 lists some general-use criteria for dermal filler products ...