Absorption Rates of Various-thickness Human Acellular Dermal Grafts(SureDerm(R))

Kim, Hyun Tai; Ahn, Sang Tae; Park, Jae Gu

Abstract

The human acellular dermal graft provides safe and lasting volume gain for soft tissue augmentation in the face. However, variable amounts of the graft are gradually reabsorbed in the host tissue. The purpose of this experiment is to evaluate the absorption rates of the implanted acellular dermal grafts (SureDerm(R)) and to estimate the amount of overcorrection in the soft tissue augmentation. Twenty-eight New Zealand white rabbits were divided into 4 groups. A 2.0x 2.5 cm sized subcutaneous pocket was created on the dorsal surface of the ear. 10x10 mm sized SureDerm(R) sheets, each 1 mm, 2 mm, 3 mm and 4 mm in thickness were implanted into the pockets. Ear thickness was measured by Thickness Gauze at the time of pre-operative, immediate post-operative, 4, 8 and 12 weeks after implantation. Full thickness ear was harvested in 4, 8 and 12 weeks and examined histologically for graft thickness, host tissue ingrowth, neocollagen synthesis and inflammatory reaction. Ear thickness was mildly increased due to swelling and inflammatory reaction in the initial 4 weeks in all groups and then was decreased in 12 weeks by 84%. However, there was a significant decrease in the thickness of the graft itself (43%). There was no significant difference in the ear thickness among the groups (p<0.05) with time. Histological analysis of implanted SureDerm(R) sheets demonstrated progressive neovascularization, fibroblast infilteration, neocollagen bundle synthesis and organization. Our experimental study suggests that the absorption rate of SureDerm(R) is quite uniform regardless of the thickness of the graft. The amount of overcorrection is relatively predictable and 18% of overcorrection seems to be needed for satisfactory result.