Tissue Breakdown and Exposure Associated with Orbital Hydroxyapatite Implants

Remove, rotate, and reimplant: a novel technique for the management of exposed porous anophthalmic implants in eviscerated patients

“…Causes of implant exposure are infection, edema, hemorrhage, and exposure and are related to wrapping material, pegging, surgical technique used, too-large implant size, and surgeon's experience as reported by Viswanathan et al 4 Tension on wound, spicules on HAP implant surface, 21 pressure of prosthesis on conjunctival surface, 9 inadequate vascularization of implant, 2 tissue restitution, or long-term adductive rotation of the implant 22 are other factors that cause anterior tissue breakdown. Shields et al 2 suggested that conjunctival defects that occurred several months or later, might be due to a poorly fitting prostheses causing pressure necrosis, anterior malplacement of the implant, inadequate closure of the Tenon's fascia over the implant, or lack of implant vascularization.…”

“…2,[5][6][7][8] The incidence of porous implant exposure in many studies varies from 0-34% with varying follow-up durations. 2,4,6,[8][9][10][11][12][13][14] Exposure rates have been shown to increase after motility peg insertion in some studies. 2,7,8,12,15 Surgical techniques for exposure repair are primary revision 11 and secondary patch grafting using various materials with and without implant removal and exchange.…”

“…Endogeneous and exogeneous materials have been used for grafting. 3,4,9,[16][17][18][19][20] Porous implant exposure management, after evisceration, may necessitate removal of the porous implant from the scleral tissue that requires blunt and sharp dissection of the fibrovascular attachments, which is often a traumatic procedure for the orbital contents and the implant covering and is generally considered a difficult surgical task. The removed implant is exchanged with a new implant, which is then placed into the remaining sclera and the Tenon's capsule.…”

“…9 Kim et al 21 recommended repair with a patch graft to increase the conjunctival area. Management of porous sphere implant exposure includes two main graft techniques: those with exogenous material versus those with autogenous material.…”

“…In dermis fat grafting technique, they eliminated the implant exposure by burying it down. 9 Tawfik et al 20 described another technique using implant capsule for closure of exposure, which occurred in an enucleated socket. In addition, their technique creates a too-thin flap and injury to the extraocular muscles, which results in incomplete closure of defect.…”