Homologous collagen dispersion (dermalogen) as a dermal filler: persistence and histology compared with bovine collagen.

To assess the biological behavior and clinical efficacy of homologous collagen dispersion (Dermalogen) in augmenting human dermis, Dermalogen and bovine cross-linked collagen (Zyplast) were compared in a human postauricular injection model. Dermalogen (two sites implanted behind one ear) and Zyplast (two sites behind the contralateral ear) were injected into an upper to middermal level in 20 healthy adults. Digital photographs of all implant sites were taken over a 12-week period after injection. Biopsies of each implant type were taken at 4 and 12 weeks after injection. At 12 weeks after injection there was a small but significant difference in persistence rates between Dermalogen and Zyplast (4% vs. 2%; = 0.005). Histologically, Dermalogen was identifiable at 4 weeks after implantation, with evidence of neovascularization. Zyplast was identified more uniformly than Dermalogen in specimens 12 weeks after implantation, and more chronic inflammatory cells and foreign body giant cells were seen in the Dermalogen specimen. Clinical persistence and the histological behavior of Dermalogen appears to be at least as favorable as Zyplast bovine collagen. Dermalogen does not require pretesting and can also be used in the patient already sensitized to bovine protein. For these reasons, the authors think Dermalogen is a reasonable alternative to bovine collagen for facial soft-tissue augmentation.