Dermal filler complications from unknown biomaterials: identification by attenuated total reflectance spectroscopy.

[BACKGROUND] In the last decade, an increase in complications related to dermal filler injections has been reported, especially in patients who underwent multiple treatments with different products. Imaging or histological examinations may suggest what kind of substance was used, but none can precisely identify the biomaterial. The aim of this study was to evaluate the use of Fourier transform infrared spectroscopy, using an attenuated total reflectance cell, in the identification of unknown dermal fillers.

[METHODS] In the preclinical study, samples from different manufacturers were analyzed according to attenuated total reflectance spectroscopy using the Nicolet 8700 FT-IR spectrophotometer (resolution, 0.125 cm; Thermo Fisher Scientific, Inc., Madison, Wis.). Spectra of each biomaterial were collected and included in a reference database. In the clinical study, seven patients affected by severe complications due to multiple injections with unknown fillers provided a sample of the pathological tissue for the analysis.

[RESULTS] Two granulomas, two infiltrated tissues, and three abscesses were studied. Attenuated total reflectance/Fourier transform infrared analysis of pathological tissues revealed the presence of absorption bands absent in the healthy tissue. Comparison of these bands to the filler database made it possible to identify the dermal fillers injected.

[CONCLUSIONS] This pilot study has demonstrated the absolute validity of the application of infrared spectroscopy in attenuated total reflectance for the determination of infiltrated biomaterial. The knowledge of the previously injected fillers may be crucial to selecting the appropriate medical or surgical treatment as well as to solving medical-legal issues.