Orbital floor reconstruction using porcine small intestinal submucosa.

Background: We conducted a prospective, controlled, blinded pilot study to demonstrate that repair of induced rabbit orbital floor fractures with Surgisis ES (Cook Biotech Inc, West Lafayette, Ind) provides adequate orbital content support while promoting mucosal and bone regeneration of the fracture site.

Material/methods: Ten New Zealand white rabbits underwent induced bilateral controlled (5mm) orbital floor fractures under anesthesia. In each rabbit, Surgisis ES, an acellular, freeze-dried soft tissue matrix derived from porcine small intestinal submucosa, was implanted subperiosteally to repair one orbital floor fracture through a transconjuntival approach. The contralateral orbital floor fracture served as a control. Histological assessment was performed at 1, 3, and 12 months post-operatively.

Results: All ten rabbits survived the surgery without infection, globe entrapment or implant rejection. Grossly, the orbits appeared similar in the ten rabbits. Subtle histological differences were noted between the fractures repaired with Surgisis ES and those left to heal without treatment. Eosinophilic infiltrates and connective tissue fibrosis found to varying degrees in the Surgisis ES sites were not found in the control sites. Previous Surgisis studies found a foreign body giant cell reaction that was absent in this study. Both sites were healed at all intervals.

Conclusions: Surgisis ES can successfully serve as a graft in the repair of orbital floor fractures in rabbits. However, its ability to promote central bone regeneration has not been clearly established. Additional studies investigating its application in human orbital trauma are needed.