Introduction

Soft tissue fillers are used to fill wrinkles and folds, to add volume lost during senescence, to sculpt facial structure, and to correct defects such as scars and facial lipoatrophy. Soft tissue augmentation utilizing temporary fillers continues to be among the most commonly performed cosmetic procedures. The increasing demand is due to a population demanding facial rejuvenation with less invasive approaches, fast actualization of results, and minimal morbidity. In 2009, approximately 1.5 million injections of temporary filler agents were performed amongst all board-certified physicians practicing cosmetic surgery, representing a significant increase over previous years. Given their favorable safety profiles, effectiveness, and versatility, and the availability of multiple filler options, it is expected that the popularity of these products will continue to increase. Despite their impressive safety record, complications and adverse events can occur. The number of complications may increase as more people begin seeking this type of intervention and more injectors begin providing these services. In particular, there has recently been an alarming trend of increasing numbers of untrained or poorly trained physicians and non-physicians using these products; therefore one needs to be prepared to see complications in our offices even if we were not the injector.

Materials approved for soft tissue augmentation can be divided into biodegradable, semibiodegradable, and non-biodegradable products. These classifications correlate with their duration of effect as being temporary (approximately 6–12 months), temporary-plus (duration up to 18 months), or permanent (Box 26.1). As more fillers become available, it is imperative to understand the differences between them, the complications that can occur from each, and how best to avoid and treat them when they do occur.

Potential complications associated with temporary soft tissue fillers can be categorized by the time of onset (Box 26.2). In general, adverse events can be subdivided into acute and delayed reactions. Acute reactions are procedural or related to injection technique. They are usually transient and are manifested by erythema, edema, ecchymosis, pruritus, and pain in the first week after injection. Delayed reactions are related to the product itself, or the interaction between the filler and the host response. They are usually manifested by persistent erythema, swelling, nodules, and indurations developing months to years after. The nature of these reactions and their treatment will be summarized in this chapter.

Injection site reactions

The most common adverse events associated with fillers are local injection site reactions, manifested by pain, erythema, and edema. They are typically mild, localized, and transient, resolving within 4–7 days. A recent study by Brandt et al evaluating the efficacy and safety of biphasic hyaluronic acid Restylane^® and Perlane^® in the lower face revealed that the majority of patients treated with both small and large gel-particle hyaluronic acid experienced at least one injection site reaction. The reported events in decreasing order of occurrence consisted of bruising, tenderness, swelling, and redness. In another study comparing hyaluronic acid (Restylane^®) with collagen (Zyplast^®) for the treatment of nasolabial folds in contralateral sides, injection site reactions occurred at 93.5% and 90.6% of the hyaluronic acid and collagen treated sites, respectively. The bruising can be severe, especially in patients who have taken antiplatelet agents such as aspirin or non-steroidal anti-inflammatory agents, as shown in Figure 26.1.

Figure 26.1 Severe periocular ecchymosis 7 days following injection of hyaluronic acid deep into the supraperiosteal fat pads.

Pain

Pain is often one of the commonly reported adverse events associated with filler agents. Pain is often attributable to hydrostatic dissection of tissue during injection, as well as the discomfort of numerous needle punctures during the implantation of the product. Certain anatomical sites such as the lips and perioral region are more sensitive as a result of increased sensory innervation of these sites. A number of techniques may be utilized to minimize the pain associated with injections. These include the use of topical anesthetics, application of ice before and after injection, and vibratory distraction. Some clinicians also utilize infraorbital and mental nerve blocks. Placement of small aliquots of lidocaine along a few points of the gingival sulcus has also been found to be beneficial in minimizing pain associated with injections of the lips. In the past 18 months, a number of fillers have begun to package the filler syringe pre-mixed with lidocaine.

Edema and ecchymosis

Some of the most common post-procedure adverse events are bruising and swelling secondary to local trauma from the injection (Fig. 26.1). Reviewing all medications and supplements with the patient can minimize the degree of edema and ecchymosis. Avoidance of agents that inhibit coagulation is recommended, including aspirin (unless taking for ‘therapeutic’ indications) and non-steroidal anti-inflammatory medications, as well as supplements such as garlic and Ginkgo biloba that have an inhibitory effect on platelets. Other supplements such as vitamin E, fish oil, glucosamine, ginger, ginseng, green tea, and celery root can inhibit coagulation pathways and further increase bleeding and bruising. It is recommended to withhold these supplements at least 5 days prior to treatment.

Bruising can often be minimized by choosing the injectable filler least likely to cause this problem. Collagen-based fillers were less likely to cause ecchymosis secondary to their inherent platelet-aggregating properties. However, they are not available at the time of this writing. Conversely, it has been suggested that hyaluronic acid fillers have an anticoagulant effect and can cause more swelling and bruising because they are structurally similar to heparin.

When bruising occurs there are a few things that can be employed to minimize the degree and duration of the ecchymosis. Some advocate supplements such as bromelain and homeopathic Arnica in reducing post-treatment ecchymosis. Bromelain been shown to decrease vascular permeability in animal models by lowering the levels of bradykinin, thereby potentially resulting in less edema, pain, and inflammation. Helenalin, an extract of Arnica, has been shown to possess anti-inflammatory effects and inhibits platelet function in vitro. Clinical studies of both these compounds have provided conflicting results, with some revealing a decrease in post-treatment bruising, whereas others show no statistical difference. Further investigations are needed to substantiate their effect. Aside from these ‘natural’ remedies, some physicians choose to minimize post-treatment ecchymosis by utilizing their vascular laser at purpuric treatment settings.

Nodules and papules

Inappropriate placement of fillers may result in the development of subcutaneous nodules and papules. The majority of these are manifested as palpable and / or visible bumps under the skin. Injecting too superficially can lead to lumps of visible product, or bluish bumps under the skin explained by the Tyndall effect with hyaluronic acid fillers (Fig. 26.2). Such reactions can, for the most part, be prevented by use of correct technique. Treatment of visible papules can often be accomplished by firm digital pressure, by aspiration, or by incision and drainage. When persistent papules and nodules are due to the use of a hyaluronic acid filler, the enzyme hyaluronidase can be utilized to treat them.

Figure 26.2 The Tyndall effect is shown following injection of the hyaluronic acid Restylane^® intradermally in the superior modiolus.

The incidence of injection site nodules from temporary fillers appears to be higher in patients receiving poly-l-lactic acid (PLLA; Sculptra^®), particularly in the HIV-infected population. In early clinical studies conducted in Europe, nodules at the site of injection that were asymptomatic, palpable but generally not visible were described in approximately 30–50% of patients, and without treatment they tended to persist for months to years. Subsequent studies in the USA reported a lower incidence of PLLA papules and nodules, occurring in approximately 6–13% of patients. In a more recent study comparing PLLA with collagen for the correction of nasolabial fold rhytides in non–HIV-infected patients, nodules <5 mm in diameter occurred in 8.6% of patients receiving PLLA and 3.4% of those receiving collagen. Nodules >5 mm diameter occurred in 6.9% of subjects receiving PLLA and 6.0% of subjects receiving collagen.

In the past few years, Narins and others have recommended changes in the protocol for product reconstitution, dilution, and administration that have helped limit this potential complication. PLLA should be reconstituted approximately 24–48 hours prior to injection with approximately 7–8 mL of bacteriostatic water, with 1 mL of lidocaine added at the time of injection. Product placement in the appropriate deep injection planes will help minimize nodules. Figure 26.3 shows a visible periocular papule following too-superficial placement of PLLA using an older dilution technique. For injection of the cheek, preauricular area, nasolabial folds, and lower face, injection should be into the deeper subcutaneous plane. For treatment of the temples, PLLA should be injected beneath the temporalis fascia, and for injection of the zygoma, maxilla, and mandibular regions, depot injection in the subperiosteal plane is desired. Care should be taken not to inject the precipitate at the end of the syringe. Following implantation, vigorous massage of the treatment area with instructions for the patient to massage at home is recommended. The post-treatment ‘rule of 5s’ is easy for the patients to remember: massage 5 times per day, for 5 minutes, for 5 days.

Figure 26.3 An obvious small non-inflamed papule in the periocular region following injection of PLLA. An older more concentrated dilution technique was used and the product placed too superficially. This nodule was subsequently excised and showed particles of PLLA and no inflammation.

Even with recent alterations in protocol to minimize this complication, papules and nodules may still occur, as illustrated by a recent case report of a woman who developed numerous nodules 3 years after PLLA injections. This may be more likely due to a delayed foreign body reaction or a reaction to a latent infectious process rather than to product placement. It is important to note that differences in regional thickness of skin can increase the chances of injection site nodules. The incidence of late-onset nodules has been reported to be greater in areas such as the periorbital and perioral region as well as the dorsal hands. Diligence is needed when injecting these sites and treatment should not be performed by novice injectors.

Inflammation (hypersensitivity reactions)

With the exception of autologous fat, all soft tissue augmentation agents are composed of foreign-body material. As a result, varying degrees of immune system reactivity can occur. It is important to be able to recognize inflammatory reactions and be able to manage them.

Prior to the introduction of hyaluronic acids in 2004, the most common agent for soft tissue augmentation was bovine collagen in the form of Zyderm 1^®, Zyderm 2^®, and Zyplast^®. Given its animal source, it could be immunogenic resulting in allergic reactions. Two separate skin tests were recommended to test for sensitivity, as 3% of the population may develop a delayed hypersensitivity response. In other studies, it has been reported that the incidence of foreign-body reactions is approximately 1.3%. Allergic reactions to bovine collagen may be treated with topical, intralesional, or a brief course of systemic corticosteroids, or other topical immunomodulators such as tacrolimus.

To avoid the risk of hypersensitive adverse reactions to bovine collagen, human-based collagen was then generated for injection. Obtained from human donor tissues, Cosmoderm^® and Cosmoplast^® were the most frequently used agents within this class. There are very few cases of true hypersensitivity reactions to human-derived collagen fillers. However, one must be aware that it may still rarely be possible. There are some physicians who favor collagen products and some patients who still request it for their augmentation; however, it is not available at the time of this publication.

Hyaluronic acid is one of the components of the extracellular matrix of the dermis and has no organ or species specificity. When introduced to the market, NASHA™ (non-animal stabilized hyaluronic acid) compounds were thought to have been considered to be non-immunogenic. In fact, in spite of its frequent use for cosmetic reasons, there are very few descriptions of hypersensitivity reactions secondary to injections of hyaluronic acid. A case of circulating antibodies against hyaluronic acid in patients after several injections was reported; however, these findings could not be confirmed by other investigators. In a recent randomized clinical trial utilizing Restylane^® and Perlane^®, researchers failed to detect clinical or laboratory evidence for elicitation of humoral (type I hypersensitivity) or cell-mediated (delayed type IV hypersensitivity) immunity to NASHA™ in the majority of patients treated. At most, it is estimated by some experts that one in every 10 000 individuals undergoing augmentation with these materials reports a clinical hypersensitivity reaction. Many now feel, based on their clinical course and response to treatment, that a number of these reported hypersensitivity reactions are likely due to an infectious process.

Severe systemic hypersensitivity reactions secondary to injections of hyaluronic acid fillers are even more rare than local side effects. A case was reported in 2009 of a patient who developed acute facial angioedema, accompanied by generalized urticarial lesions, pruritus, and fever 3 weeks after implantation of 1 mL of NASHA™ (Restylane^®) in her nasolabial folds. The patient subsequently developed palpable purpura on the trunk and extremities with a biopsy consistent with leukocytoclastic vasculitis. Whether this was a true immunologic reaction in this specific case is questionable; however, it is important to be conscious that there may be coincidental or idiosyncratic reactions with the use of dermal fillers.

In cases where there have been reports of clinical hypersensitivity reactions, it is postulated that the reactions were caused by residual proteins or impurities resulting from the manufacturing process, rather than by the hyaluronic acid itself. There were two sources for industrial production of the hyaluronic acid used as agents for soft tissue augmentation: an animal hyaluronic acid produced from rooster combs (Hylaform^®), and a non-animal stabilized hyaluronic acid produced by bacterial fermentation from specific strains of streptococci (Restylane^® family, Juvéderm^® family, and Belotaro^®). Some studies have shown that low-molecular-weight fragments obtained from different preparations of hyaluronic acid stimulated the synthesis of interleukin-12 and tumor necrosis factor alpha in monocytes, and that these findings might explain the rare reports of delayed hypersensitivity reactions in patients treated with hyaluronic acid injections. In early European use of NASHA™, delayed hypersensitivity reactions were reported at relatively low incidences, 0.15–0.42%. Since then, manufacturing processes have become even more stringent, subsequently reducing the protein load by sixfold and virtually eliminating the incidence of implant-site hypersensitivity reactions.

Though the incidence is low, there have been case reports of localized and generalized hypersensitivity reactions, immune-mediated granuloma formation, and sarcoidosis-like disease following injection with temporary soft tissue fillers. A rare, but dramatic, type of reaction that was reported in 2005 was an angioedema-type hypersensitivity to 1 mL of Restylane^® following injection into the upper lip. One hour after injection, the patient developed an angioedema-type swelling of the upper lip without systemic complaints. The patient was treated with intramuscular corticosteroids with stabilization of swelling occurring 2 hours later, and was subsequently treated with an oral steroid taper with complete resolution of edema within 5 days.

Infection

As with any procedure where there is a breach in the structural integrity of the skin, infection after injection of temporary soft tissue fillers can occur. Potential infectious etiologies may be bacterial, fungal, or viral in nature. It is possible that trauma from injection may trigger recurrent herpetic lesions. Therefore, in patients with a history of herpes outbreaks, prophylactic antiviral treatment is recommended if the filler is to be used for the purpose of lip augmentation; alternatively avoid the site of the herpetic outbreak. Delay filling if an active herpes lesion is present near the area of augmentation.

To minimize the risk of infection, one should consider a more formal sterile surgical preparation utilizing chlorhexidine. Commonly recovered bacterial microorganisms associated with injections of dermal fillers include Staphylococcus and Streptococcus. Patients with a lesion clinically suspicious for an infection often present with a single or multiple tender erythematous and / or fluctuant nodules. This may be accompanied by systemic symptoms such as fever and fatigue. When an infection is suspected, the lesion should be cultured or biopsied, and the specimens sent for bacterial, fungal, and acid-fast stains. Empiric treatment with an antibiotic such as clarithromycin should be initiated until the more specific culture results become available.

When a lesion that may be infectious in nature appears at the site of injection more than 2 weeks post-procedure, it may be suggestive of an atypical infection, such as a Mycobacterium organism. There have been reports of an outbreak of M. chelonae infection after soft tissue augmentation with a hyaluronic acid-based filler. It is not clear whether the injected material was contaminated with the mycobacteria during the manufacturing process, or whether the patient was inoculated during the injection procedure. Contamination of the filler agent is of concern, as there have been individuals who utilized non-US Food and Drug Administration (FDA)-approved products and have illegally imported products outside of approved US distributors. With the expansion of non-physicians and untrained personnel performing aesthetic procedures, and with the possibility that non-FDA-approved agents or even counterfeit products are being used, it is possible that we may see an increase in these types of complications.

Biofilms

A biofilm is a quiescent infection by bacteria, introduced at the time of injection, resulting in the formation of a structured community of microorganisms adherent to an inert surface and encapsulated by a protective self-developed polymeric matrix. Biofilms are extremely difficult to eradicate, as they are often resistant to the immune system and conventional anti-infectives. The most common biofilm-forming microorganisms responsible for about two-thirds of infections with foreign material are Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Enterococcus species. Biofilms may also be composed of fungal elements such as Candida. Biofilm formation is a crucial step in the pathogenesis of many subacute and chronic bacterial infections. They have been problematic to many fields of medicine ranging from orthopedic devices to heart valves, indwelling catheters, and stents. Active clinical infections have flared weeks, months, and even years after the initial surgery. It is now acknowledged that biofilms are a concern when utilizing temporary fillers for soft tissue augmentation.

Biofilm reactions have been reported more frequently when a permanent non-degradable gel such as silicone or polyacrylamide gel is injected: however, they can occur with the use of temporary filler agents as well. Following filler injections, there may be both acute and delayed onset of erythematous papules and nodules. Some of these reactions have been reported years after injection of the product. Often culture of these lesions will lead to negative results as standard culturing techniques are not sensitive enough to detect these types of infections, leading some to incorrectly refer to them as ‘sterile abscesses’. It is important to understand how a biofilm can be responsible for many filler side effects, particularly those that present as early- or late-onset ‘angry red bumps’. Biofilms can result in a clinical picture of an inflammatory response, a local infection including an abscess or cellulitis, a systemic infection with sepsis, a granulomatous response with a foreign-body granuloma, or a nodule (Fig. 26.4). It has been noted that subsequent trauma or injection at sites of previous filler placement can activate biofilms with the possible induction of a ‘granulomatous or an infectious response’.

Figure 26.4 Potential complications from biofilms.

Any inflammatory nodule should first be treated as an infection. The first treatment of choice for most papules and nodules, whether they are red and / or painful, should be an antibiotic such as clarithromycin for 2–6 weeks, in lieu of initial treatment with intralesional corticosteroid injections. If these lesions are treated initially with steroids, intralesionally or systemically, it can make the inflammation much worse by further activating the biofilm and prolonging the infectious process. Intralesional steroid injections should be used only if the patient is already taking an antibiotic. If the substance injected is a long-lasting particulate filler, excision must be considered if antibiotics and steroids are not successful (Box 26.3).

As biofilm-associated infections are difficult to treat, it is extremely important to employ a sterile reliable antiseptic protocol for skin cleansing prior to injection so as to prevent early colonization. High-risk patients such as immunocompromised patients and diabetics, who are more prone to infection, need special attention. Patients with chronic sinusitis and chronic dental problems may have a greater tendency to develop an infection after a filler is injected in the periorbital area or central face.

Biofilm bacteria show much greater resistance to antibiotics than do their free-living counterparts. One potential reason for this increased resistance is the penetration barrier that biofilms may present to antimicrobials. In addition, bacterial biofilms have several antimicrobial resistance mechanisms. Recent investigations have identified genes that may be specifically involved in increased antibiotic resistance of biofilm cells. It has been shown that bacteria in biofilms have enhanced penicillin resistance as a result of a dual strategy: impaired penetration of the biofilm through its matrix, and rapid efflux of the antibiotic. Other molecular studies have cast light on new facts about the virulence factors of biofilms. The biofilm matrix has been shown to include a variety of structural components, including DNA, polysaccharides, and proteins. This finding has stimulated interest in developing substances that enzymatically disrupt these elements leading to a breakdown of the biofilm. Others have been investigating the role of photodynamic therapy to disrupt biofilms. Research continues to ascertain the mechanics of pathogenic biofilms, which could lead to the development of new drugs to combat them.

Granulomas

Although it happens infrequently, local and regional delayed and recurrent granulomatous reactions, manifested as persistent nodules, may complicate non-permanent dermal filler injections. As all synthetic fillers act as foreign bodies, the host response ranges from a few macrophages to an intense foreign-body reaction with fibrosis, depending on the filler. A fibrotic response by the patient is often the desired basis of volumization for products such as PLLA and calcium hydroxylapatite (Radiesse^®). These granulomas are usually secondary to an inflammatory response to a specific product and there is speculation that the composition and the size of the filler agent can be associated with the risk of developing this type of reaction. It is not yet fully understood why these granulomas develop years after injection.

As collagen is usually resorbed in approximately 3–4 months, the risks of delayed or persistent granulomas are quite low. Rare examples of pallisading granulomas resembling granuloma annulare and disseminated and recurrent sarcoid-like granulomatous panniculitis have been reported in the past following bovine collagen injections. Hyaluronic acid products have been rarely associated with granuloma formation, as evidenced by delayed erythema and either painful or non-tender swollen nodules. Whether this reaction is due to an inherent continuous foreign-body reaction or to a biofilm is up for debate. Many problems that were previously assumed to be foreign-body granulomas or allergic reactions on the basis of negative bacterial cultures are now thought to be due to biofilms. As stated previously, recent evidence has pointed to bacterial contamination at the time of device implantation as a potential etiology of these granulomatous responses.

Nevertheless, there have been reports of true granulomatous reactions to Restylane^®. In a specific case, a patient received a hyaluronic acid product in the vermilion border and subsequently developed discrete nodules initially associated with eczematous changes in the overlying skin 6 weeks after injection. Histological analysis revealed the presence of a sharply demarcated nodule in the subcutaneous fat that was consistent with a granulomatous foreign-body reaction to the filler. These granulomas have been shown at times to respond to intralesional steroids and calcineurin inhibitors. In cases of hyaluronic acid-related granulomatous foreign-body reactions that do not respond to initial treatment with topical anti-inflammatory medications, hyaluronidase may be employed to resolve the problem.

There have been reports of histologically confirmed foreign body granulomas to poly-l-lactic acid as well at the sites of injection. The granulomatous reaction to PLLA particles may persist for at least 18 months after injection. Bacteria have been searched for to find the etiology of this reaction, but no microorganisms were detected by DNA analysis of the granulomatous reaction in a series of cases. There has been a concern of a vigorous granulomatous response to PLLA in patients who have had immune reconstitution, where a previously immunodeficient patient became relatively immunocompetent while being treated for HIV. The hypothesis is that these patients may develop an overactive response to infectious or foreign substances. One paper reported three cases with significant visible deformity as a result of foreign-body-induced giant-cell granulomatous reactions following skin augmentation. These reactions were attributed to the aberrant reactivity of the recipient to the material. Treatment with intralesional steroids and 5% imiquimod cream resulted in no visible clinical improvement, and excision was required to remove the largest of nodules. Severe systemic adverse effects secondary to PLLA injections are extremely rare, with only one case being described as an anaphylactic reaction necessitating treatment interruption. As noted previously, with appropriate deposition technique and adequate dilution, late-onset foreign body granulomas are reported to be rare, with overall incidence in studies as low as 0.1%. Nevertheless, patients and physicians must be aware of this potential side effect.

Injectable calcium hydroxylapatite tends to be associated with a high incidence of nodules when this agent had been injected into the lips. However, these nodules do not appear to be inflammatory in nature. Histologically, microspheres of calcium hydroxylapatite stimulate almost no foreign-body reaction, and only a few macrophages are seen around the injected material. Migration of this product from the original site of injection to a distant location has been described with this filler and it should be avoided for augmentation of the lips.

Necrosis

Necrosis of the skin is a rare, but severe, complication following injection of temporary fillers. Judicious use of the fillers with proper placement and selection of products and recognition of this serious complication is vital. There have been reports of all filler agents leading to necrosis of the skin. Some experts have seen an increase in the incidence of necrosis following injections, possibly paralleling the rise in treatments. There is a growing concern regarding the varied experience level and training backgrounds of those who are treating the expanding market.

Necrosis can result from inadvertent placement of filler within the lumen of a vessel, or from compression of blood vessels if excess product is used – both of which can lead to obstruction of blood flow with resulting tissue necrosis. This often presents with a mottled pattern of violaceous discoloration of the overlying skin that was treated. If not recognized and ameliorated this can progress to further discoloration, pain, and ulceration with resultant scarring of the skin upon healing. The areas at greatest risk for injection necrosis and complications is in the glabellar region corresponding to the supratrochlear artery and its small-caliber branches that supply this watershed region with minimal collateral circulation. This complication can also occur along the course of facial artery, angular artery, lateral nasal artery, or their branches. An appreciation of normal facial anatomy, with consideration given to location and course of major arteries and differences between regional properties and thickness, is of importance to minimize this complication.

A number of precautions can be taken to avoid necrosis. Aspiration before injecting, injecting slowly in an anterograde manner, and keeping the needle constantly mobile are all advised. Selection of appropriate agents that are small in particle size and are intended for superficial use is also imperative in helping to minimize this complication. Also avoid injection in the immediate vicinity of large named facial vessels. Some experts have recently adopted the use of blunt-tipped cannulas, which would likely reduce the risk of intravascular cannulization.

Impending necrosis presents in one of three patterns: immediate, early (within 24–48 hours), or delayed. Treatment is dependent on the time of onset. First recognition of vascular compromise is evident by blanching followed by a dusky or purple discoloration of the area. Upon recognition of this, injection should be immediately discontinued. Applying warm compresses and massaging the area will facilitate vasodilation and blood flow. Approximately inch (12 mm) of 2% nitroglycerin paste should be massaged onto the affected area, which will often result in revascularization as manifested by a pink hue within a few minutes. Skin testing with hyaluronidase should be performed, and if no hypersensitivity to this agent is seen then 10–30 units diluted in a 1 : 1 ratio with saline should be injected per 2 × 2 cm² area into the region of impending necrosis. Hyaluronidase has been shown to reduce edema, which could minimize occluding vessel pressure. Therefore hyaluronidase is of benefit in the management of impending necrosis even if not utilizing a hyaluronic-based filler. In more severe or unresponsive cases of necrosis, Schanz and colleagues described their success using deep subcutaneous injections of low-molecular-weight heparin into the affected area.

Conclusion

Soft tissue augmentation with temporary fillers continues to be among one of the most commonly performed cosmetic procedures. Performed with good care and by experienced physicians, it is a highly effective, extremely well-tolerated procedure. As both the number of patients seeking injections and the types of fillers expands, it is imperative that physicians have the proper training and are familiar with their potential complications and treatment. Though complication rates are generally low with these classes of agents, they can still occur even in the best of hands; therefore, early recognition and management of them are imperative. To ensure the best possible outcomes while minimizing avoidable adverse events, a thorough understanding of facial anatomy as well as proper product selection and injection techniques is required.