Risk factors for orbital implant exposure after evisceration: A case control study of 93 patients

Purpose: The study aims to analyze risk factors for exposure of orbital implants after evisceration by comparison of patients with and without exposure of implants. Methods: This is a case control study in retrospective interventional case series; Group A- implant exposures after evisceration, Group B - Patients on follow up after evisceration with implant, without exposure, with matched duration of follow up. The sample size is calculated for a power of 80. Results: Group A comprised 32 sockets with implant exposure, presenting at median 18 months after surgery; Group B included 61 eviscerated sockets, without implant exposure, with follow up median 36 months. Odds Ratio (OR) was calculated; infected eyes -OR 1.3, P = 0.6; phthisical eye - OR 1.4, P = 0.43; multiple prior surgeries- OR 1.55, P = 0.33. Group A had 59.3% porous implants, Group B 55.7%, - OR 1.3, P = 0.5. Mean implant size in Group A 19.06 mm, Group B 18.78 mm- showed no statistical difference. Multiple logistic regression analysis showed no significant risk factor for exposure. Surgeon factor was not analyzed since there were multiple surgeons. Conclusion: This is the first study with calculated sample size, comparing implant exposure patients to a control group. Porous implant material, presence of infection, phthisical scleral shell, and prior surgery showed higher trend of exposure (Odds ratio >1), but none was conclusive. Larger size of implant was not a risk factor for exposure. Eliminating the role of several factors in implant exposure allows the surgeon to make better surgical choices: such as place an implant of appropriate size, of a material of surgeon's choice, and do primary placement of implant in a patient with evisceration post-corneal ulcer or endophthalmitis. A hypothesis and a recommendation is that meticulous attention be paid to surgical technique.

Treatment of Exposed Hydroxyapatite Orbital Implants Wrapped with a Synthetic Dura Substitute

PURPOSE: To describe cases of exposed hydroxyapatite (HA) implants wrapped with the synthetic dura substitute Neuro-Patch treated via simple Neuro-Patch removal. METHODS: The medical records of seven patients who experienced exposure of their HA implant were reviewed. All patients had been enucleated and implanted with HA wrapped with Neuro-Patch. For treatment, Neuro-Patch was removed to the greatest extent possible. After applying local anesthesia with lidocaine, blunt dissection was performed to separate the conjunctiva and Neuro-Patch via the site of exposure. Pressure was applied to the remaining Neuro-Patch with forceps and removed with scissors. RESULTS: Neuro-Patch was visible at the area of exposure in all patients. No surgery beyond initial Neuro-Patch removal was necessary in six of the seven patients. In five cases, the exposed area began to heal rapidly after Neuro-patch removal without primary closure of the defect. In one case, the Neuro-Patch material and all necrotic tissue was removed aggressively due to inflammation around the orbital implant. Lastly, an infection was noted in one case, prompting complete removal of the Neuro-Patch–wrapped HA implant. CONCLUSIONS: Wrapping material may hinder implant vascularization. Exposure of HA in wrapped implants can be successfully treated by a simple removal procedure if detected and managed early.

Clinical investigation of mucosal thickness stability after soft tissue grafting around implants: A 3-year retrospective study.

Purpose: To assess the long-term stability of gingival grafts placed around dental implants at the time of second surgery uncovering and to further investigate the association between mucosal thickness (MTh) by demographic variables and clinical investigation. Materials and Methods: Fourteen patients with submerged dental implants covered by inadequate keratinized mucosa were studied. The subjects underwent a periimplant plastic surgery (PPS) at the second-stage dental implant surgery and free gingival autograft orsubepithelial connective tissue graft were used according to the patients' clinical situation. Clinical measurement of MTh was assessed by bone sounding with a periodontal probe using customized acrylic stents andthe values were recorded at baseline (day of graft) and at 0.5, 1.5, 4, 12, 24 and 36 months after grafting. Results: At 12 months postoperatively, the mean MTh was 2.89 mm, with a mean additional increase of 1.75 mm when compared with baseline (P=0.0001). No statistically significant differences in MTh were found between the 12- and the 36-month observations (P=0.09). In addition, at 36 months, a thin mucosa was associated with a greater increase in the MTh compared with a thick mucosa (2.14 and 0.64 mm, respectively, P=0.006). Similarly, the mandibular sites were associated with a greater increase in the MTh in comparison with the maxillary sites (2.17 and 0.81 mm, respectively; P=0.02). Conclusions: Within the limitations of this investigation, the data suggest that PPS at the second-stage dental implant surgery could results in additional increases in MTh, especially when it is performed in areas where the mucosa is of a thin biotype.

Preservation of Exposed Breast Implant for Immediate Breast Reconstruction

PURPOSE: Common complications of immediate breast reconstruction with implant are capsular contracture, malposition of implant, hematoma and seroma. Especially, the most severe complication is implant exposure caused by inflammation or necrosis of skin flap margin of mastectomy site. This article reports the experience of cases of salvage in such an exposure of implant. METHODS: From July, 2002 to Feb., 2009, sixty-five patients who underwent immediate breast reconstruction with implant were retrospectively analyzed. Exposure of implant was happened in 5 of 65 patients and they were treated at out patient district. Two of five patients were reconstructed with saline implnt and all of them underwent the enveloping of the implant with AlloDerm(R) and Serratus muscle flap. Remaning three patients were reconstructed with silicone implant and all of them underwent the enveloping of the implant with AlloDerm(R). RESULTS: In the group of patients who underwent reconstruction with saline implant, implant exposure was found in one patient due to partial necrosis of the margin of skin flap and debridement and primary repair were done. In the other one patient, dressing with antibiotic ointment were done. And debridement and primary repair were proceeded. In the group of patients who underwent reconstruction with silicone implant, implant exposure was found in one patient. After removal of the implant, tissue expansion was done and a new silicone implant was inserted. Implant exposure were found in the other two patients, antibiotics ointment application and primarily repaired. CONCLUSION: It was the common knowledge that the exposed implant should be removed. But salvage of the exposed implants may be possible with proper treatment. Four of five patients (80%) with exposed breast implant were salvaged with conservative management.

The Effect of 4 Rectus Muscle Anterior Displacement in Porous Polyethylene Orbital Implant Exposure

PURPOSE: To investigate the effects of anterior displacement of four rectus muscles in exposure of porous polyethylene orbital implant (Medpor(R)). CASE SUMMARY: This retrospective study reviewed 4 eyes with exposed orbital implant who underwent evisceration with porous polyethylene orbital implant (Medpor(R)). The technique involves dissection of conjunctiva and tenon's capsule and isolation of four rectus muscles from sclera. Unsure if each muscle was sutured to each other or if a group of muscles were sutured to another group (i.e. superior and inferior to medial and lateral). Posterior tenon's capsule was closed interruptedly and conjunctiva was closed continuously. Orbital implant exposure was occurred at 2~36 months later after evisceration and implant insertion. One eye was noted wound dehiscence 1 week after operation, then re-suture was done. Re-exposure was notified in 1 eye at postoperative 3 months, but it was small, then we just observed. In other 3 cases, exposure was not identified till last follow up. CONCLUSIONS: Four rectus muscle anterior displacement procedure may be simple and useful method in exposure of orbital implant.

A Case of Medpor(R) Orbital Implant Infection

PURPOSE: Porous orbital implant Medpor(R) which is made of polyethylene is being widely used currently. Compared with previously used porous orbital implants, it is somewhat preferred due to cheaper and easier usage but reports on its postoperative complications are not sufficient. We report the first case of Medpor(R) infection developed domestically. METHODS: A 20 year-old male patient was admitted with Medpor(R) infection 14 months after Medpor(R) orbital implant insertion. He was treated with antibiotics. RESULTS: Infection was controlled with antibiotics without implant removal. Implant exposure occurred after infection control so dermis graft was done.

Clinical Effect of Porous Polyethylene (Medpor(r))Orbital Implant

Porous polyethylene (Medpor(r))implant offers several advantages over other implant materials. Its porosity allows fibrovascular ingrowth which promotes host integration, prevents migration and reduces the likelihood of opportunistic infections. The authors used the porous polyethylene (Medpor(r)) as a central orbital implant in 36 eyes of the 36 patients. They underwent enucleation (17 cases), evisceration (16 cases), and a secondary implantation (1 cases)between November 1997 and June 1999. A mean follow-up period was 8.9 months (range, 3 to 17 months). There were 5 cases of implant exposure and 4 cases of superior sulcus deformity. There were no infection of implant, implant migration, or extrusion of motility coupling post. Postoperatively, all sockets showed good to excellent motility of prosthesis. Porous polyethylene (Medpor(r))can be used successfully as an orbital implant in anophthalmic socket surgery. Its advantages over other similar implants include a significantly lower material cost and the ability to suture the extraocular muscles directly to it without the need for a covering material such as fascia or sclera.

Clinical Experiences of Hydroxyapatite Implant

The hydroxyapatite has been used as an orbital implant for reconstruction after enucleation or evisceration. It has been known to be a biocompatible and nontoxic implant with good fibrovascular ingrowth, few postoperative complications, excellent prosthesis motility, and good cosmesis. We performed 36 cases of hydroxyapatite implantation with enucleation or evisceration from July 1992 to August 1994. The mean follow-up period was 7.4 months(range, 4 to 13 months). There were nine cases of implant exposure. three cases of peg extrusion, three cases of superficial conjunctival wound dehiscence, and one case of granulation tissue overgrowth. There was no infection of implant. Improving the postoperative results and reducing the postoperative complications, it requires proper surgical techniques including the selection of adequate implant size and good doctor-patient relationship.