Analysis of Facial Implants for Bacterial Biofilm Formation Using Scanning Electron Microscopy

Alloplastic implants are widely used in facial plastic surgery, both in rhinoplasty and nonrhinoplasty procedures. Implant infection and extrusion are significant concerns of such implants after placement. Bacterial biofilms have been previously implicated in chronic wound infections, particularly in the presence of foreign bodies, such as alloplastic facial implants. Owing to their structural composition, biofilms are resistant to treatment with conventional antibiotics, and implant removal is frequently the only option.

To evaluate explanted alloplastic facial implants for the presence or absence of bacterial biofilm using scanning electron microscopy.

Facial implants explanted by a single surgeon were analyzed for biofilm formation between July 1, 2012, and June 30, 2013. Of 7 facial implants, 4 consisted of silicone, and 3 were porous polyethylene. Six of the 7 were nasal dorsal implants, and 1 silicone implant was removed from the midface. Nonexplanted fresh silicone and porous polyethylene implants were each used as a control.

Scanning electron microscopy images were analyzed by an electron microscopist masked to the clinical history and implant type. The presence of biofilm formation was graded as none, mild, moderate, or severe.

A total of 7 patients with previously placed alloplastic facial implants at an outside institution underwent revision rhinoplasty and removal of facial implants. All porous polyethylene implants showed biofilm formation to various degrees. Furthermore, all porous polyethylene implants had at least some areas of severe biofilm formation. One of the 3 porous polyethylene implants demonstrated severe biofilm formation on the entire implant, and the other 2 porous polyethylene implants showed areas of mild and severe biofilm formation. The only 2 implants without any evidence of biofilm were silicone implants. Of the other 2 silicone implants, 1 demonstrated no biofilm formation in 1 area and severe biofilm formation in another area, whereas the other had areas of moderate and severe biofilm formation.

Five of 7 explanted facial implants showed at least some degree of biofilm formation. All implants with rougher surfaces, namely, porous polyethylene implants, demonstrated biofilm formation to a severe degree. Those with smoother surfaces, namely, silicone implants, were the only ones on which biofilm formation was either absent or less severe. Therefore, the suspicion that biofilms can form on facial implants is established through this investigation.

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