Unacceptable results with an accepted soft tissue filler: polyacrylamide hydrogel

The histologic reaction and permanence of hyaluronic acid gel, calcium hydroxylapatite microspheres, and extracellular matrix bio gel

BACKGROUND

The filling materials on the beauty market can be classified into three types: natural biological materials, synthetic polymer materials, and composites containing bioactive substances. However, comparative experimental data is lacking to compare their biological responses and permanence.

AIMS

The main object of this study was to evaluate the biological response of these three types of fillers to provide a theoretical basis for clinical application.

METHODS

Six-week-old female mice were injected subcutaneously with hyaluronic acid (HA) gel, calcium hydroxylapatite (CaHA) microspheres, and extracellular matrix (ECM) bio gel to observe the body reaction and permanence. At 1, 4, 8, and 16 weeks, the test sites were excised and analyzed by histopathology and proteomics.

RESULTS

Extracellular matrix had a minimal foreign body response. HA had a good volume effect at the early stage but the volume retention rate was lower than CaHA in the long term. CaHA could stimulate neo-collagen formation.

CONCLUSION

This study has proven the effectiveness and safety of these fillers and could provide clinical guidance for the plastic surgeon.

Safety and Efficiency of Minimally Invasive Buttock Augmentation: A Review

BACKGROUND

Volume restoration and enhancement of the gluteal region appearance has become nowadays a popular concern in particular for many women. Several options are available, none however are without complications and side effects. Volume enhancement with soft tissue fillers of the gluteal region is emerging as a highly attractive minimally invasive modality. It has led unfortunately to more unlicensed, nonmedical practitioners administering illicitly injections for buttock augmentation at relatively low costs.

MATERIALS AND METHODS

To determine safety, efficacy, and cost effectiveness of mostly used soft-tissue fillers for buttock augmentation, a systematic literature search of PubMed, Medline, and Embase was conducted to identify the mostly used fillers for gluteal augmentation. It was complemented by searching for each of the identified filler material separately to retrieve any missed reports. References of clinical studies and trials, reviews, and consensus reports were reviewed as well for the same objective.

RESULTS

In the final analysis 12, mostly strongly biased clinical reports providing a low level of evidence, were identified for inclusion in the review. Two studies involved Polymethylmethacrylate (PMMA), 5 Poly-L-lactic acid, 1 Calcium hydroxyapatite and 4 hyaluronic acid filler injection. No studies were identified involving liquid silicone or Polyacrylamide hydrogel. The little available evidence provided by this review indicates that a specific brand of PMMA in Brazil has a demonstrable relatively good safety, efficiency, and cost-effectiveness record superior to surgical alloplastic gluteal augmentation or to lipofilling only when injected by experts.

CONCLUSION

Gluteal augmentation with soft tissue fillers is not as simple and innocuous as advertised. Serious complications may occur. Moreover, optimal buttock contouring entails not only volume augmentation but also volume removal; thus, volume augmentation with soft tissue fillers may not be ideal. Popularizing this modality must also be approached with great care. Serious complications do occur; they become inevitable when performed illegally by non-specialized, non-authorized, and unscrupulous practitioners in non-accredited facilities. Patients must be warned that adherence to regulations is critical and that only well-trained certified experts practicing legally in accredited facilities can address safely and efficiently their concerns.

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 .

Abscess Formation After Tooth Extraction: A Long-Term Complication of Polyacrylamide Hydrogel Filler

A 35-year-old woman with a history of polyacrylamide hydrogel filler injection was referred with a fluctuating facial abscess after decayed tooth extraction. MRI imaging confirmed the diagnosis of an abscess. After appropriate treatment, the patient healed with a little hyperpigmentation and deformity in the zygomaticotemporal area. Although polyacrylamide hydrogel filler injection is considered non-toxic, non-immunogenic, and biocompatible; as a permanent material, physicians should be aware of the risk of its late complications such as late infections. In addition to antiseptic measures, antibiotic prophylaxis may be necessary before the procedures which have a risk of bacteremia and close to the permanent filler location.

Self-Healing Injectable Hydrogels for Tissue Regeneration

Biomaterials with the ability to self-heal and recover their structural integrity offer many advantages for applications in biomedicine. The past decade has witnessed the rapid emergence of a new class of self-healing biomaterials commonly termed injectable, or printable in the context of 3D printing. These self-healing injectable biomaterials, mostly hydrogels and other soft condensed matter based on reversible chemistry, are able to temporarily fluidize under shear stress and subsequently recover their original mechanical properties. Self-healing injectable hydrogels offer distinct advantages compared to traditional biomaterials. Most notably, they can be administered in a locally targeted and minimally invasive manner through a narrow syringe without the need for invasive surgery. Their moldability allows for a patient-specific intervention and shows great prospects for personalized medicine. Injected hydrogels can facilitate tissue regeneration in multiple ways owing to their viscoelastic and diffusive nature, ranging from simple mechanical support, spatiotemporally controlled delivery of cells or therapeutics, to local recruitment and modulation of host cells to promote tissue regeneration. Consequently, self-healing injectable hydrogels have been at the forefront of many cutting-edge tissue regeneration strategies. This study provides a critical review of the current state of self-healing injectable hydrogels for tissue regeneration. As key challenges toward further maturation of this exciting research field, we identify (i) the trade-off between the self-healing and injectability of hydrogels vs their physical stability, (ii) the lack of consensus on rheological characterization and quantitative benchmarks for self-healing injectable hydrogels, particularly regarding the capillary flow in syringes, and (iii) practical limitations regarding translation toward therapeutically effective formulations for regeneration of specific tissues. Hence, here we (i) review chemical and physical design strategies for self-healing injectable hydrogels, (ii) provide a practical guide for their rheological analysis, and (iii) showcase their applicability for regeneration of various tissues and 3D printing of complex tissues and organoids.

In vitro and in vivo methods to study bacterial colonization of hydrogel dermal fillers

Preclinical in vitro and in vivo methods to study bacterial interactions with dermal fillers and infection pathogenesis are lacking. In this work, first in vitro methods to assess protein biofouling and effective pore size of commercial dermal fillers, including degradable hyaluronic acid (HA)-based fillers and other semi-degradable or permanent fillers (non-HA), were developed. The results were then related to Staphylococcus aureus (S. aureus) adhesion rates in vitro. HA fillers had less protein sorption than non-HA fillers and overall had smaller effective pore sizes. The properties correlated with levels of bacterial adhesion, where the control glass surface had the most rapid increase in bacterial cell adhesion, with a slope of 0.29 cm^-2  min^-1 , three unique non-HA fillers had intermediate adhesion with slopes of 0.11 and 0.06 cm^-2  min^-1 , and three unique HA fillers had the least adhesion with slopes of 0.02, 0.02, and 0.01 cm^-2  min^-1 . S. aureus had greater motility on the HA fillers than on non-HA fillers. Next, a mouse model for dermal filler biofilm and infection was developed. Mice were inoculated with a controlled amount of bioluminescent bacteria (Xen36 S. aureus) and polyacrylamide hydrogels of different stiffness were injected. In vivo bioluminescence was monitored longitudinally for 35 days to ensure that lasting colonization was established. The inoculum was optimized to achieve adequate bioluminescent signal, and bacterial bioburden over time and inter-animal variability in bioburden were determined. These in vitro and in vivo approaches can be used for future studies of antimicrobial interventions for dermal fillers.

Multiple Delayed Complications at Different Time Points After AQUAfilling Filler Injection for Facial Rejuvenation

ABSTRACT

Delayed inflammatory and infectious complications occurred in a 63-year-old woman after receiving AQUAfilling filler injection in the forehead and nasolabial folds. The complications were idiopathic and occurred at different time points at different sites. Her condition improved after the removal of the injected materials and capsule, and administration of intravenous antibiotics. Although injection sites differ, inflammation can occur at any site at different time points. The possibility of inflammation at other injection sites should always be considered during periodic follow-up, even if the filler injection site initially shows no signs of complications.Level of Evidence: Level IV.

Complications Following Non-Surgical Aesthetic Treatments in HIV+ Patients Receiving Antiretroviral Therapy: A 12-Years Experience

Since the advent of HIV antiretroviral therapies at the end of the 20th century, the morbidity and mortality rates associated with HIV infection have decreased dramatically. Unfortunately, these benefits are associated with substantial morphologic changes in the body, such as abnormal fat distribution with peripheral lipohypertrophy and facial lipoatrophy. Facial wasting is considered the major stigma for HIV–infected people and may result in reduced antiretroviral adherence. Patients suffering from the stigmata of HIV infection can benefit from non-surgical aesthetic treatments performed with fillers or lipolytic agents that provide a quick and reliable service for facial rejuvenation, with high patient satisfaction and a low risk of complications. In the present paper, a retrospective analysis of complications following non-surgical aesthetic treatments (calcium hydroxyapatite-based filler, hyaluronic acid filler, polyacrylamide hydrogel filler and dehoxycholic acid injections), in a cohort of 116 consecutive HIV+ patients, treated over a period of 12 years, was performed. With the exception of the tardive swelling reported after calcium hydroxyapatite injections, complications were recorded just after polyacrylamide hydrogel treatment as small, palpable, nonvisible nodules or aseptic abscess. Our experience is consistent with those already published in the literature and the complication rate seems to be comparable to non-infected patients.

Safety of Copolyamide Filler Injection for Breast Augmentation

Although injections with copolyamide fillers (Aquafilling/Los Deline and Aqualift/Activegel) are currently used widely for breast augmentation, many complications have been reported. A recent position statement by a Korean aesthetic/reconstructive breast surgery society indicated these fillers are the same as polyacrylamide gel (PAAG), which is widely prohibited due to complications. To test this statement, this retrospective cohort study examined the clinical complications after breast augmentation with copolyamide fillers. Nuclear magnetic resonance (NMR) analysis of copolymer and PAAG fillers was also conducted.

Does (mis)use of industrial liquid silicone implants interfere with bone mineral density in transgender women?

The effects of gluteal implants on bone mass remain unclear. Transgender women with ILS presented higher BMD in the hip compared with transgender women without implants, while no difference was observed in other sites. These results may be artifactual and suggest using spine/forearm sites for DXA in individuals with ILS.

PURPOSE

The inappropriate use of industrial liquid silicone (ILS) injections for cosmetic purposes is practiced by some transgender women. The aim of this study was to evaluate the impact of gluteal ILS on femur BMD in transgender women.

METHODS

A total of 46 trans women with and without ILS injection in the gluteal region were selected. All patients underwent clinical and hormonal evaluation, and bone mass was assessed by DXA.

RESULTS

Bone mineral density (BMD) values were significantly higher in trans women with ILS (n = 23) in femoral neck and total femur when compared with trans women without implants (n = 23). Similar BMD was observed in other sites, such as lumbar spine and forearm. Good agreement was found in the evaluation of low BMD using spine/forearm or spine/femur in patients without implants (k = 0.744 and 1.000 for male and female reference database, respectively), but poor to fair index was found in patients with ILS implants (k = 0.330 and 0.646 for male and female reference database, respectively).

CONCLUSIONS

In transgender women with ILS implants, poor to moderate agreement was found on BMD when comparing lumbar spine/femur DXA with an alternative site to the femur, depending on using male or female database. These results may be artifactual and suggest using spine/forearm sites for more accurate DXA assessments in trans women with ILS gluteal implants.

Hydrogel-Based Technologies for the Diagnosis of Skin Pathology

Hydrogels, swellable hydrophilic polymer networks fabricated through chemical cross-linking or physical entanglement are increasingly utilized in various biomedical applications over the past few decades. Hydrogel-based microparticles, dressings and microneedle patches have been explored to achieve safe, sustained and on-demand therapeutic purposes toward numerous skin pathologies, through incorporation of stimuli-responsive moieties and therapeutic agents. More recently, these platforms are expanded to fulfill the diagnostic and monitoring role. Herein, the development of hydrogel technology to achieve diagnosis and monitoring of pathological skin conditions are highlighted, with proteins, nucleic acids, metabolites, and reactive species employed as target biomarkers, among others. The scope of this review includes the characteristics of hydrogel materials, its fabrication procedures, examples of diagnostic studies, as well as discussion pertaining clinical translation of hydrogel systems.

Simple, selective and fast detection of acrylamide based on glutathione S-transferase

Acrylamide (AA) is a toxic compound formed in thermally prepared foods by Maillard reaction. Besides foods, AA may be found in cosmetic products as an impurity of the widely-used non-toxic polyacrylamide. We present a novel, fast and selective detection method based on the amperometric monitoring of the coupling reaction between reduced glutathione (GSH) and AA catalyzed by glutathione S-transferase (GST) to produce an electrochemically inactive compound. We have used electrodes modified with cobalt-phthalocyanine to monitor the decrease of GHS concentration at +300 mV. Our system is simple, does not require supplementary substrates such as 1-chloro-2,4-dinitrobenzene (CDNB) nor have disadvantageous competitive kinetics characteristic to inhibition like signals. Using the optimum concentration of 100 μM GSH we have obtained a linear calibration graph from 7 to 50 μM AA and a limit of detection of 5 μM AA. The method is not affected by interfering compounds usually found in foods and was applied for real sample analysis.

[Plasma management in complex treatment of late inflammatory complications after injection contour plasty with polyacrylamide gel]

AIM

To improve the results of treatment of late inflammatory complications after injection contour plasty with polyacrylamide gel.

MATERIAL AND METHODS

The authors analyze treatment of 21 patients with late septic complications of body contour plasty with polyacrylamide gel (PAGE) for the period 2010-2015. Mean age of women was 47.4 years. Time after primary intervention was 10-22 years. The depth of soft tissue lesion corresponded to II-III grade by D. Ahrenholz classification (1991), length - from 67 to 180 cm2. Mammary glands were the most common area of augmentation (18 cases). Besides antibiotic therapy and surgery complex treatment included exposure with plasma flows in various modes.

RESULTS

Plasma technology significantly accelerated regenerative processes and provided stable microbial decontamination in 100% patients. High-energy vaporization was associated with maximum possible removal of PAGE from the tissues that was confirmed by histological examination.

Engineered Hydrogels in Cancer Therapy and Diagnosis

Over the last decade, numerous investigations have attempted to clarify the intricacies of tumor development to propose effective approaches for cancer treatment. Thanks to the unique properties of hydrogels, researchers have made significant progress in tumor model reconstruction, tumor diagnosis, and associated therapies. Notably, hydrogel-based systems can be adjusted to respond to cancer-specific hallmarks and/or external stimuli. These well-known drug reservoirs can be used as smart carriers for multiple cargos, including both naked and nanoparticle-encapsulated chemotherapeutics, genes, and radioisotopes. Recent works have attempted to specialize hydrogels for cancer research; we comprehensively review this topic for the first time, synthesizing past results and defining paths for future work.

Resolution of Cosmetic Buttock Injection-induced Inflammatory Reaction and Heart Failure after Excision of Filler Material

We present a case of a 66-year-old woman who developed heart failure and severe inflammatory reaction after the illicit cosmetic injections of polymethyl-methacrylate or polyacrylamide hydrogel from a primary care provider. After medical optimization, an en bloc excision of all injectable materials and gluteus muscle was performed, which resulted in exposure of bilateral sciatic nerves. Within 10 days, the patient's heart failure resolved and inflammatory state improved. This is the first known report of heart failure due to buttock injections and subsequent improvement after surgery.

Treatment of complications from polyacrylamide hydrogel breast augmentation

Polyacrylamide hydrogel (PAHG) is a medical soft tissue filling agent utilized for the treatment of a variety of soft tissue defects. However, postoperative complications occur that have to be alleviated. The aim of the present study was to examine the treatments of postoperative complications of mammoplasty augmentation with PAHG. Open suction techniques and partial mastectomies via periareolar incisions were performed in 28 patients who had been injected with PAHG for breast augmentation. The PAHG was removed precluding breast complications resulting from the hydrogel injections. The symptoms disappeared completely, and the results were satisfactory following removal of the PAHG. In conclusion, the periareolar approach is valuable and removes PAHG to the greatest extent.

Aesthetic Surgery of the Buttocks Using Implants: Practice-Based Recommendations

The demand for gluteal enhancement has increased rapidly in the past few years. In this Continuing Medical Education (CME) article, the evaluation, surgical planning, operative technique, and management of potential complications of gluteal augmentation using solid silicone implants are discussed. Practice-based recommendations are presented along with a review of the scientific literature. The intramuscular and subfascial technique is described along with a discussion of the advantages and disadvantages of each approach. Guidelines for implant selection, placement, and revisional procedures are presented along with recommendations for maximizing successful outcomes.

Nonthrombotic Pulmonary Embolism: A Potential Complication of Polyacrylamide Hydrogel Cosmetic Injection

Context. Polyacrylamide hydrogel (PAAG) has gained importance as a synthetic soft tissue filling agent. It has been commonly employed by physicians in Europe for facial contouring and soft tissue augmentation. Previously, PAAG is considered nontoxic and well tolerated with a few mild procedural complications. Case Presentation. A 26-year-old female was hospitalized for dry cough, worsening dyspnea, and chest discomfort after 3 hours of multiple PAAG injections in buttocks. The patient's condition deteriorated and rapidly advanced to acute respiratory failure. Therein, the diagnosis of nonthrombotic pulmonary embolism (NTPE) was established on standard set of investigations. She was intubated; corticosteroid and empiric antibiotic therapy was initiated resulting in improvement of her condition. Subsequently, extubation was done, and she was discharged from the hospital after an uneventful recovery. On 1-month follow-up, the patient had no previous symptoms. Conclusion. This report implicates clinicians to maintain a high index of suspicion for NTPE in patients presenting with respiratory symptoms following PAAG usage.

Introduction to Fillers

BACKGROUND

Over the last few years, injectable soft-tissue fillers have become an integral part of cosmetic therapy, with a wide array of products designed to fill lines and folds and revolumize the face.

METHODS

This review describes cosmetic fillers currently approved by the Food and Drug Administration and discusses new agents under investigation for use in the United States.

RESULTS

Because of product refinements over the last few years-greater ease of use and longevity, the flexibility of multiple formulations within one line of products, and the ability to reverse poor clinical outcomes-practitioners have gravitated toward the use of biodegradable agents that stimulate neocollagenesis for sustained aesthetic improvements lasting up to a year or more with minimal side effects. Permanent implants provide long-lasting results but are associated with greater potential risk of complications and require the skilled hand of the experienced injector.

CONCLUSIONS

A variety of biodegradable and nonbiodegradable filling agents are available or under investigation in the United States. Choice of product depends on injector preference and the area to be filled. Although permanent agents offer significant clinical benefits, modern biodegradable fillers are durable and often reversible in the event of adverse effects.

Polyacrylamide gel 10 years experience: with particular reference to complications from filling of the body of the lip

BACKGROUND

A review of 242 facial treatments, in 86 different patients, with polyacrylamide gel (PAAG) was carried out by the author between 2003 and 2013.

OBJECTIVES

To evaluate by retrospective study the long-term outcomes of PAAG filling for facial contouring. To quantify adverse events and patient comfort in prior mixing 0.3 mL of 2% lidocaine/1 mL PAAG and decanting into a smaller volume syringe.

METHOD

Review of clinical records combined with a patient survey.

RESULTS

COMPLICATIONS

11 of 166 (6.6%) lip body infections; 1 of 202 (0.5%) in other sites. Addition of 2% lidocaine (55 treatments/28 patients) reduced lip body infections (8.7% to 5.7%, P < 0.05%) and mean pain score (8/10 to 2/10). No patients sustained any long-term side effects and all (even those infected) were eventually satisfied. Seven lip asymmetries, after infected PAAG drainage, were corrected with further PAAG, showing adverse events to be contamination rather than immune reaction.

CONCLUSION

Facial usage of PAAG with lidocaine results in high levels of patient satisfaction and low incidence of side effects (0.5%) except in the lip body (6.6%). Potential users, fearful of complications, may more readily use this cost-effective and long-lasting dermal filler if they avoid injection of the lip body.

Polyacrylamide gel breast augmentation: report of two cases and review of the literature

Polyacrylamide gel (PAAG) injection remains an uncommon method of breast augmentation. Providers must recognize the clinical and radiological manifestations to optimize management. The clinical and radiological findings of PAAG injection may mimic malignancy and silicone breast augmentation. We described two patients with prior PAAG breast augmentation with physical exam and imaging findings concerning for malignancy. We reviewed the literature on PAAG breast augmentation and compare PAAG to silicone breast augmentation. The management of such patients is discussed.

Emerging permanent filler technologies: focus on Aquamid

A plethora of soft tissue fillers have been developed within the past decade to correct the cutaneous changes that occur with photoaging. Such fillers, whether nonpermanent, semipermanent, or permanent, are widely used to fill undesired facial rhytides. In addition, fillers are employed to correct atrophy of the face as well as other parts of the body such as the dorsum of the hands through volumization and contouring. The extensive long-term safety outcomes reported with fillers and the ease with which they are administered make them an ideal choice to correct rhytides and to contour the face. However, as with any cosmetic procedure, in order to ensure high patient satisfaction and a safe outcome, proper training in injection techniques, the choice of the proper candidate, and awareness of potential adverse events are essential. This review article focuses on the permanent filler, Aquamid, which is composed of polyacrylamide hydrogel.

Polyacrylamide hydrogel pulmonary embolism--A fatal consequence of an illegal cosmetic vaginal tightening procedure: A case report

Vaginal tightening is a kind of esthetic surgery aimed at enhancing sexual satisfaction during intercourse. Although the injective vaginal tightening procedure is informal, there are already some reports of its application. But pulmonary embolism is a really rare therapeutic complication of this procedure. We report a case of death due to the non-thrombotic pulmonary embolism as a consequence of illegal cosmetic vaginal-tightening procedure using polyacrylamide hydrogel. A 34-year-old woman was hospitalized with paroxysmal abdominal cramps and diarrhea as initial symptoms, while she concealed the genital cosmetic surgery history. Respiratory distress presented only 1.5h before she died. The result of autopsy revealed the cause of death as pulmonary embolism due to the hydrogel which was injected into her vaginal wall. The emboli were confirmed as polyacrylamide hydrogel by Alcian-blue stain and the Fourier transform infrared scanning. It is suggested that pulmonary embolism should not be discarded in the expertise of deaths following cosmetic implant surgeries. It broadens our understanding about death associated with esthetic genital procedures and informs clinicians and medical examiners of the potential death of this type. And detailed investigations of previous medical and surgical history will always play a critical role in the certification of cause of death.

Clinical data on injectable tissue fillers: a review

Treatment with injectable tissue fillers for aesthetic purposes is increasingly popular. In parallel with this success, questions related to the safety of these treatments and the products involved are being raised more prominently. To gain insight in the safety aspects of injectable tissue fillers, we performed a literature review to collect studies reporting clinical data of injectable tissue fillers. We found several case reports where serious complications after more than three years are described. However, there are only a limited number of well-defined prospective clinical studies available with follow-up periods longer than three years. Furthermore, causes of complications, that is, treatment or product related, are often not specified in literature. Considering the intended functional period of fillers in combination with the known occurrence of long-term complications, there is a need for well-defined prospective clinical studies. In order to be able to discriminate between product failure (a product safety issue) or application methodology (a physician expertise or training issue), better identification of observed complications and whether they are product or treatment related, is needed. For the safe use of the fillers it is important that treatment with injectable tissue fillers is performed by a trained physician, who knows the product specifications and its applications.

A Case of Foreign-Body Granuloma of the Glabella due to Polyacrylamide Filler and an Intractable Ulcer after Skin Biopsy: An Immunohistochemical Evaluation of Inflammatory Changes

INTRODUCTION

Polyacrylamide hydrogel has been considered a safe and biocompatible soft tissue filler, and it has been widely used in cosmetic procedures. However, recent studies have revealed some complications with polyacrylamide filler injections.

CASE REPORT

We present the case of foreign-body granulomas of the glabella, which subsequently formed an infectious ulcer 3 years after a polyacrylamide injection. An immunohistochemical evaluation of the foreign-body granulomas was performed in order to study the relationship between foreign-body granulomas and immune response.

CONCLUSION

We believe that our analysis of foreign-body granulomas 1 and 3 years after a filler injection may contribute to revealing the mechanism of chronic and intractable infections after filler injections.

Complications of injectable fillers, part I

Dermal filling has rapidly become one of the most common procedures performed by clinicians worldwide. The vast majority of treatments are successful and patient satisfaction is high. However, complications, both mild and severe, have been reported and result from injection of many different types of dermal fillers. In this Continuing Medical Education review article, the author describes common technical errors, the signs and symptoms of both common and rare complications, and management of sequelae in clear, easily adaptable treatment algorithms.

What would surgeons like from materials scientists?

Surgery involves the repair, resection, replacement, or improvement of body parts and functions and in numerous ways, surgery should be considered human engineering. There are many areas in which surgical materials could be improved, but surgeons are generally unaware of materials available for use, while materials scientists do not know what surgeons require. This article will review some of the areas where surgeons and materials scientists have interacted in the past and will discuss some of the most pressing problems which remain to be solved. These include better implant materials for hernia repair, breast reconstruction, the treatment of diabetes, vascular stenting and reconstruction, and electrical pacing devices. The combination of tissue engineering and nanomaterials has great potential for application to nearly every aspect of surgery. Tissue engineering will allow cells or artificial organs to be grown for specific uses while nanotechnology will help to ensure maximal biocompatibility. Biosensors will be combined with improved electrodes and pacing devices to control impaired neurological functions.

Infections associated with body modification

Although exact statistics are lacking, body modifications for cosmetic purposes are performed in many countries. The commonest forms include tattooing, body piercing, and breast and facial augmentation using implants or injectable fillers. Liposuction and, to a lesser extent, mesotherapy are also practiced in many countries. Infective complications of these procedures include local infections, transmission of bloodborne pathogens (viral hepatitis and human immunodeficiency virus), and distant infections such as infective endocarditis. Presence of foreign bodies, long healing time of piercing wounds, and poor compliance with infection control practices of some practitioners all predispose the recipients to infections. Apart from the endogenous microbial flora of the skin and mucosae, atypical mycobacteria, especially the rapid growers, have emerged as some of the most important pathogens in such settings. Outbreaks of infection are commonly reported. We hereby review the current knowledge of the topic with specific focus on infections associated with tattooing, body piercing, breast augmentation, mesotherapy, liposuction, and tissue filler injections. Greater awareness among consumers and health-care professionals, as well as more stringent regulations by the health authorities, is essential to minimize the health risks arising from these procedures.

Delayed gel indurations as an adverse effect of polyacrylamide filler and its easy treatment

Background. The more increasing use of permanent soft tissue fillers such as polyacrylamide hydrogel (PAAG) for aesthetic purposes, the more adverse events resulting from them are reported. Occasionally, nonserious complications and misdiagnosis result in unnecessary surgeries and sequels. Objective. To introduce delayed gel indurations (DGIs) as a late onset complication of PAAG and its easy treatment. Patient and Methods. Twenty patients (17 females and 3 males) referred to us with subcutaneous mass at injected site of PAAG. We diagnosed DGI based on clinical and sonography findings and treatment was performed with a hole by 16-gauge needle and squeezing. Results. From 20 patients with 21 cases of DGI, 5 (23.8%), 5 (23.8%), and 5 (23.8%) cases in cheeks, glabella, and lips were seen, respectively. The time range between PAAG injection and presentation of patients was 10-28 months (mean = 17.5%). All of the patients responded very well to treatment without recurrence and any complications. Conclusion. DGI is a nonserious, late onset, and easily treated complication of PAAG that is probably induced due to water exchange between gel and surrounding tissue and modest host immune reaction to gel.

Adverse results with PMMA fillers

BACKGROUND

Various alloplastic materials have been used for filling depressions and for body contouring. Among them, polymethylmethacrylate (PMMA) has provoked many clinical compilations in both the acute and chronic phases. This study shows the correlation between the clinical application of PMMA and the physiopathology of the acute and late complications.

METHODS

Histological studies were performed on biopsy samples from patients who presented with side effects and acute and late complications after PMMA injections given at other health-care centers or aesthetic services.

RESULTS

The histological findings of the samples that were harvested from patients who developed clinical complications or side effects caused by injection of PMMA disclosed not only normal tissues from the implanted areas but also development of capsules that involved individual microspheres of PMMA, and when the capsules were close together they formed concentric capsular groups involving various sets of microspheres and their capsules.

CONCLUSIONS

The injection of PMMA within the tissues can cause severe complications and side effects in both acute and chronic phases. Initially, the complications are related to vascular compromise, but at the late phase they are a consequence of capsular contracture that involves particles of PMMA. The contracture causes local tissue hardening and clinical nodulation of the implanted areas, ending with extrusion of the filler material.

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 at www.springer.com/00266.