Complicações relacionadas ao uso de polimetilmetacrilato na face

Abstract

The search for minimally invasive procedures for facial rejuvenation and remodeling has been increasing in recent years. The use of polymethylmethacrylate (PMMA) represents one of the options that has gained a lot of popularity. This polymer is composed of variable- sized PMMA microspheres that are dispersed in some vehicle such as bovine collagen, polyethylene glycol or hyaluronic acid. It is considered a permanent filler product. Despite the apparent simplicity in the method of application, complications related to this procedure, especially in the face, have increased and are often severe, unpredictable as to the time of onset or anatomical region involved. This study sought to retrospectively assess important points in this population and clarify the median time of occurrence of complications, the most frequent regions of occurrence, the type of clinical manifestation and any previous treatments. In addition, we sought to clarify whether there was a relation between the number of times PMMA was injected and an earlier time of complication onset and to determine whether there was a difference in the occurrence of complications according to sex and age. A retrospective descriptive study of cases from a restricted (observational) population that sought treatment in the author’s private clinic from January 2000 to June 2021 was carried out. Through information obtained from the electronic medical record, 209 individuals with complications related to previous injection of polymethylmethacrylate (PMMA) in the face, performed by other medical professionals, were enrolled. Complications were classified according to information obtained from the history and clinical examination, imaging examination, anatomopathological study and/or photographic analysis. The following variables were described and analyzed: age, sex, number of times PMMA was injected, type of complication and its anatomic location, time of onset of the complication, procedures previously performed by other professionals to treat the complications and the anatomic area most frequently involved in complications. In describing the occurrence of events evaluated over time, the statistical analysis was based on the development of Kaplan-Meier curves. The comparison between the studied groups was performed using the log-rank test. Values of p < 0.05 were considered statistically significant. The mean age was 44.6 years with a standard deviation of 12.2 years; 172 were women and 37 were men. The age of highest incidence of cases was 35 years. Data analysis showed a median time to onset of complications of 71 months after the initial injection of PMMA in the face. The earliest complication occurred just one month after injection of this product and the latest at 330 months. The malar (48.8%) and mandibular (47.8%) regions were the most affected areas, followed by the zygomatic (43.5%) region, mentum (27.8%), lips (27.3%) and nasolabial folds (22.0%). The nose (10%), eyelids (8.6%), glabella (8.6%), temporal area (7.2%), forehead (1.9%) and ears (1.0%) were also involved with complications, but less frequently. The most frequent complication was granuloma, present in 64.6% of patients, followed by edema (57.4%) and inflammation (37.3%). Functional alterations, formation of nodules, neovessels, alterations in skin pigmentation, tearing, infection, necrosis and fistula formation were also found in the study. The most common treatment was local injection of corticosteroids in 53.1% of patients, followed by surgical removal in 19.1%. Other resources used in an attempt to treat complications were intralesional injection of 5-fluorouracil, use of ozone therapy, aspiration of the compromised site, Bichectomy, use of xylitol, allopurinol and intralesional laser removal. In the population evaluated, there was no relationship between the number of times PMMA was injected and the time of onset of complications (p = 0.73). In the comparison between groups using the log-rank test, the value of p < 0.001 showed a statistically significant difference. Patients under 50 years of age presented complications earlier than those over 50 years of age. Complications related to the use of PMMA can occur long time after its injection. The study showed a median time of 71 months and late complications occurring more than 25 years after its application to the face. Therefore, the follow-up of patients undergoing this treatment, guidance on risks, material characteristics, complications and proper management are of fundamental importance. Although the malar, mandibular and zygomatic regions were the most affected, all areas of the face presented some type of complication. Accurate diagnosis, often aided by imaging examination or histological tests, helps in the differential diagnosis between nodules and granulomas, guiding a more specific treatment. The fact that the number of times PMMA was injected was not related to the emergence of complications, possibly the total volume injected and/or its quality, even if not evaluated, may be related to complications. The fact that the number of times PMMA was injected was not related to the early onset of complications, possibly the total volume injected and/or its quality, although not evaluated, may be related to complications. The results can serve as a knowledge base, helping to better understand the complications related to the use of PMMA on the face.