Expanded Polytetrafluoroethylene as a Wrapping Material for Porous Polyethylene Orbital Implant

ABSTRACT

PURPOSE: To investigate the possibility of expanded polytetrafluoroethylene (e-PTFE) as a wrapping material for porous polyethylene orbital implant. METHODS: Two groups of 6 female New Zealand albino rabbits underwent enucleation with placement of a 12 mm porous polyethylene orbital implant wrapped in simple e-PTFE in one group (group 1) and macro-porous e-PTFE in the other group (group 2). Histopathologic sections of the implants obtained at 4, 6, 8 weeks were compared on the extent of fibrovascular ingrowth, percentage of the area of proliferated vessel, and grade of fibrosis between the two groups. RESULTS: There was no implant exposure or severe inflammation in group 1 and 2 during the observation. The extent of fibrovascular ingrowth differs only at 4 weeks. Group 1 showed less fibrovascular ingrowth (until outer 1/3) at anterior half compared with posterior one, but there was no difference between anterior and posterior half in group 2 (until middle 1/3). The percentage of the area of the proliferated vessels was higher in group 2 than group 1 at both anterior and posterior half, and the anterior/posterior ratio of the area of vessels was also higher in group 2 than group 1. The grade of fibrosis was higher in group 2 than group 1 at 4, 6, and 8 weeks. CONCLUSIONS: Macro-porous e-PTFE almost didn't disturb fibrovascular ingrowth into the orbital implant, so macro-porous e-PTFE can be used safely as a wrapping material for porous polyethylene orbital implant.