Usefulness of acellular dermal graft as a dural substitute in experimental model

Friction injury of cortical surface or cerebrospinal fluid leakage are the major complications of polytetrafluoroethylene (ePTFE) duraplasty because of their strong surface tension and lesser adaptability. Autologous duraplasties are also accompanied by potential donor-site complications and are inappropriate for large defects. Acellular Dermal Graft (ADG), prepared from cadaver human skin, does not have the above-mentioned drawbacks because of its human nature. Moreover, the dermal basement membrane and supporting tissues remain intact, so the rate of cellular migration and transformation to the surrounding host tissue is supposed to be excellent. We studied ADG in canine model to observe the rate of transformation into the surrounding dura mater via collagen synthesis from the invaded fibroblasts to evaluate its usefulness as a duraplasty.

Dural grafting surgery was performed on 6 adult mongrel dogs weighing from 8 to 12 kgs under general anesthesia. Three dogs were sacrificed after 1 month (acute) of surgery and the other three (chronic) were sacrificed after 3 months with overdose of pentobarbital sodium. Transcardiac perfusion-fixation with 4% paraformaldehyde was done. Hematoxylin-eosin and trichrome masson stains were performed to see the graft cellularity. Thickness of grafts was also assessed along the length of the histologic sections.

Duralization, which was microscopically characterized by infiltration with regular array of collagen fibers, was observed at a few places in every high-power field in acute group. But in chronic animals, where dermal side of ADG was facing towards cranium, duralization was excellent.

Our result suggests that ADG can be considered as a useful dural substitute.