Localized inferior orbital fibrosis associated with porcine dermal collagen xenograft orbital floor implant.

We describe the clinical features, treatment, and histologic changes of a case of severe localized orbital inflammation associated with the use of porcine dermal collagen xenograft (Permacol) as an orbital floor implant in a 14-year-old boy. After uneventful blowout fracture repair with normal forced duction testing after insertion of a Permacol implant, progressive elevation and depression deficit developed in the postoperative period. There was no improvement after removal of the Permacol implant. Exploratory surgery revealed gross fibrosis of the inferior rectus muscle accounting for the abnormal ocular motility. Biopsy of the inferior rectus muscle showed chronic granulomatous inflammation suggestive of foreign body reaction. Although porcine dermal collagen xenograft has been suggested as an implant for orbital floor repair because of its reported high strength, ease of handling, and high biocompatibility, we believe that further studies are necessary before it can be recommended for this use.