Histologic comparison of cultured epithelial autograft and meshed expanded split-thickness skin graft

Histologic appearance of cultured epithelial autograft (CEA) biopsies obtained up to 2100 days after application from patients with burn injuries differs from time-matched, meshed expanded autograft. The CEA interface with underlying bed remained flat for up to 3 years in three of four patients. CEA epidermal rete ridges, if formed subsequently, were fewer, thinner, and shorter, whereas expanded split-thickness skin grafts had well-defined rete ridges after 1 year. CEA basal layer remained separated from its bed up to 50 days after application, and late blister formation was seen on occasion for up to 3 years. The underlying bed was homogeneous up to 2 years; later some beds demonstrated differentiation with superficial, fine, filamentous collagen fibers and deeper, thick collagen fibers. Fine elastin filaments were initially identified in the superficial bed after 1 year in some specimens and in all after 3 years. Delay in rete ridge formation may explain poor adherence and poor stability.