Bovine pericardium versus homologous sclera as a wrapping for hydroxyapatite orbital implants

PURPOSE: To report our experience with bovine pericardium as a wrapping material for hydroxyapatite orbital implants after enucleation and to compare the exposure rates of the implants wrapped with bovine pericardium versus donor sclera. METHODS: We retrospectively reviewed the records of all patients who received bovine pericardium-wrapped or donor sclera-wrapped hydroxyapatite implant after primary enucleation between March 1995 and December 2001. RESULTS: Of the 26 patients who received donor sclera-wrapped implants after enucleation, 1 (3.8%) had implant exposure. Of the 26 patients who received bovine pericardium-wrapped implants after enucleation, 6 (23%) had implant exposure. The incidence of implant exposure with the use bovine pericardium wrapping material was found to be significantly higher than with sclera (P = 0.05). Six of the 7 implant exposures were noted in the first 6 months after placement of the orbital implant. Five of the 6 exposed bovine pericardium-wrapped hydroxyapatite implants were associated with socket infection. The case of exposure of the sclera-wrapped implant was treated conservatively by observation. Six patients who had exposure of bovine pericardium-wrapped implants required multiple repairs because of recurrent exposures. Four of these patients eventually required removal of the implant. CONCLUSIONS: Despite the advantages of using bovine pericardium as a wrapping material for hydroxyapatite orbital implants, we observed a significantly higher incidence of exposure with bovine pericardium compared with donor sclera in the early postoperative period. Use of bovine pericardium as a wrapping material for orbital implants should be avoided unless some future modifications of the technique can be developed to prevent such complications.     

Use of bovine pericardium as a wrapping material for hydroxyapatite orbital implants

AIM: To present the results of 27 patients who had enucleation for malignant melanoma of the choroid with hydroxyapatite implant wrapped in bovine pericardium. METHOD: A retrospective study was performed on 27 patients, 12 males and 15 females, who had enucleation as a primary treatment for their choroidal melanomas. The patients were followed up at 1 week, 1 month, 3 months, and then every 6 months. A conformer was fitted at 1 week and an artificial eye at 1 month. The average follow up was 1.7 years. RESULTS: No patient had extrusion of the implant. One patient needed repair of the wound, two patients required a lateral tarsal strip, and one patient developed a conjunctival granuloma, which did not need excision. In one patient there was shallowing of the inferior fornix. The cosmetic results and ocular movement were satisfactory in all but one patient. CONCLUSION: Use of bovine pericardium as wrapping material for the hydroxyapatite implants has shown promising results with minimal extrusion rates providing an effective alternative for sclera, eliminating the potential risks of CJD.     

Safety of unwrapped spherical orbital implants

PURPOSE: To determine the exposure rate of unwrapped spherical orbital implants after enucleation surgery. METHODS: Retrospective review of consecutive case series. All patients undergoing orbital implantation during enucleation surgery from October 1999 to September 2003 were included. Charts were reviewed for preoperative diagnoses, type and size of implant, use of a wrapping material, and complications. RESULTS: Twenty-six consecutive patients underwent enucleation surgery without wrapping material. Nineteen patients received porous polyethylene, 5 patients received polymethylmethacrylate, and 2 received hydroxyapatite. Mean implant diameter was 21.03 mm. Mean follow-up was 17.1 months (range, 2 to 43 months). There were no complications of implant extrusion, exposure, infection, or migration. CONCLUSIONS: The use of unwrapped spherical orbital implants may be associated with a low rate of early exposure. Careful choice of implant type may help reduce the risk of implant exposure.     

Bovine pericardium as a wrapping for orbital implants

PURPOSE: We report the use of bovine pericardium as an alternative wrapping for porous orbital implants after enucleation. METHODS: We retrospectively reviewed the records of all patients who received a bovine pericardium-wrapped orbital implant after enucleation by the authors between August 1, 1996, and December 1, 1999. RESULTS: Eighty patients underwent placement of bovine pericardium-wrapped orbital implants. The average age at the time of implantation was 49.3 years (range, 5 years to 83 years). The mean follow-up interval was 11.8 months (range, 2 to 41 months). There were no intraoperative complications. No patient had secondary systemic infection or showed evidence of rejection. There was no clinical evidence to suggest that vascularization of the porous implant was unusually delayed, and there were no complications after secondary drilling and placement of a coupling post. Four (5%) of 80 patients had complications requiring removal of the spherical implant. All 4 patients had hydroxyapatite implants. Two patients had significant exposure requiring removal of the implant at 2 months after surgery; 1 patient had a chronic fistulous tract with secondary infection 3 years after surgery: and 1 patient had chronic orbital pain requiring removal of the implant at 1 year after surgery. CONCLUSIONS: The incidence of implant exposure was less than 4%. This compares favorably to the incidence of exposure of 9% to 21% reported in recent literature. Other complications were few and of minimal clinical significance. The authors conclude that bovine pericardium is a viable option to sclera as a wrapping for porous orbital implants.     

Wrapping hydroxyapatite orbital implants with posterior auricular muscle complex grafts

PURPOSE: To report the use of posterior auricular muscle complex grafts as a wrapping material for hydroxyapatite orbital implants in enucleation surgery. METHOD: In a retrospective multicenter study, autogenous posterior auricular muscle complex grafts were used to cover hydroxyapatite orbital implants in 83 patients with a mean age of 38.6 years (range, 1 to 85 years), of whom 63 had primary unilateral enucleation and 20 had secondary orbital implants following enucleation. The mean follow-up period after posterior auricular muscle complex grafts was 36 months (range, 14 to 60 months). RESULTS: Of the 83 patients, two (2.4%) developed limited orbital implant exposure, which was treated with a second posterior auricular muscle complex "patch graft." No patient developed postoperative orbital infection or implant extrusion. All patients were fitted with an acceptable prosthesis and had satisfactory cosmetic and functional results. No patient developed vascular compromise or a wound defect associated with the posterior auricular donor site. CONCLUSION: Autogenous posterior auricular muscle complex grafts should be considered as an appropriate wrapping material for hydroxyapatite orbital implants for primary enucleation and for secondary orbital implants after enucleation.     

Conjunctival melting syndrome associated with the use of bovine pericardium wrapping material

PURPOSE: To report 18 cases of unusually large, early conjunctival breakdown occurring with the use of bovine pericardium wrapping material for orbital implants. METHODS: Retrospective case series. The clinical course and histopathologic features of 18 cases of early conjunctival breakdown in patients who had undergone orbital implantation of bovine pericardium-wrapped hydroxyapatite or porous polyethylene are reviewed. RESULTS: Eighteen patients presented with unusually large (average 13.44 mm) conjunctival defects over bovine pericardium-wrapped implants. The average time from enucleation to exposure was approximately 4 months. Implants had to be removed in 8 of 18 cases. There was clinical and histologic evidence of tissue inflammation and conjunctival melting.CONCLUSIONS: The conjunctival melting phenomenon we report herein is alarming. We have abandoned the use of bovine pericardium as a wrapping material for implants after enucleation because of the unfavorable results.     

Mersilene mesh versus sclera in wrapping hydroxyapatite orbital implants

PURPOSE: To compare Mersilene mesh versus sclera in wrapping hydroxyapatite orbital implants used in primary enucleation. METHODS: In a prospective, randomized, interventional comparative case series, 60 eyes from 60 consecutive patients were included and randomly allocated for primary enucleation and either Mersilene mesh-wrapped hydroxyapatite (MHA) orbital implant (30 cases, 50%) or sclera-wrapped hydroxyapatite (SHA) orbital implant (30 cases, 50%) under general anesthesia. Complete socket examination was performed at 1 week, 1 month, and then every 3 months after surgery. RESULTS: Mean age was not significantly different (P = 0.08) between patients with MHA (36.43 years) and SHA (28.50 years) orbital implants. The most common cause of enucleation was trauma in both groups (P = 0.09). Patients with MHA had significantly (P = 0.005) longer follow-up time (mean, 11.40 months) than those with SHA (mean, 9.40 months). No exposure was found at last follow-up in the MHA group, but one patient in the SHA group had a small exposure (1 x 1 mm) 1 month after surgery that was conservatively treated. There were no significant postoperative soft tissue complications in either group. CONCLUSIONS: Sclera and Mersilene mesh could be used as a wrapping material for hydroxyapatite orbital implants without significant complications. Absence of disease transmission, low cost, and availability are the main advantages of Mersilene mesh.     

Porous implant exposure: Incidence, management, and morbidity

PURPOSE: To identify what factors may predispose patients to exposure of porous anophthalmic implants and to determine the outcome of exposed porous implants. METHODS: Examination of pooled data obtained through a PubMed literature search of English-language publications from 1989 through 2004 using the key words enucleation, evisceration, and socket reconstruction. RESULTS: Porous implants were inserted in 80% (3012 of 3777) of the cases identified from 49 publications. The difference in exposure rate between coralline hydroxyapatite (4.9%) and porous polyethylene (8.1%) implants is primarily related to a higher reported complication rate of uncovered porous polyethylene implants, particularly in retinoblastoma patients. Other techniques associated with increased exposures include wrapping implants with bovine pericardium or polyglactin mesh. Evisceration and secondary procedures did not have statistically different complication rates compared with enucleation. There are more late exposures of porous polyethylene than coralline hydroxyapatite implants. Spontaneous healing of exposures occurred in 13% (19 of 145) of cases. Covering exposures with patch grafts underneath vascularized conjunctival flaps was the most successful method of surgical repair. Implant removal was necessary after 29% (42 of 145) of exposures. CONCLUSIONS: Although the published literature between 1989 and 2004 reports higher complication rates for uncovered porous implants and implants wrapped with bovine pericardium or polyglactin mesh, pooling data from different studies may mask very good or poor results obtained by individual surgeons. Spontaneous healing of exposed porous implants is relatively uncommon. However, many exposed porous implants can be salvaged with secondary repair.     

Bovine pericardium versus homologous sclera as wrapping materials for hydroxyapatite ocular implants: an animal study.

PURPOSE: We compared bovine pericardium and homologous sclera as wrapping materials for hydroxyapatite (HA) ocular implants in enucleated New Zealand white rabbits. METHODS: Eighteen rabbits were unilaterally enucleated and the sockets implanted with 10-mm HA spherical implants. Six implants were wrapped with homologous sclera, 6 with bovine pericardium, and 6 were not wrapped. The rabbits were killed 7 weeks later and the sockets were examined clinically for inflammation and implant exposure. Exenterated specimens were assessed histopathologically for inflammation and vascularization. RESULTS: No clinical evidence of implant exposure or extrusion was detected in rabbits receiving sclera or bovine pericardium wrapped implants. Histopathologically, the bovine pericardium displayed more inflammation in its outer portion, as well as more disruption of its lamellar arrangement than did the sclera. Fibrovascular in-growth was complete in all wrapped implants. CONCLUSION: Bovine pericardium behaves similar clinically to homologous sclera as a wrapping material for spherical HA ocular implants in a rabbit model, and may represent a reasonable alternative to sclera in such procedures in humans.     

Orbital implants in enucleation surgery: a report by the American Academy of Ophthalmology

OBJECTIVE: To compare prosthetic and implant motility and the incidence of complications associated with porous and nonporous enucleation implants. METHODS: Literature searches conducted in January 2002 for 1985 to 2001 and May 2002 for October 2001 to 2002 retrieved relevant citations. The searches were conducted in MEDLINE and limited to articles published in English with abstracts. Panel members reviewed the articles for relevance to the assessment questions, and those considered relevant were rated according to the strength of the evidence. RESULTS: A randomized clinical trial and a longitudinal cohort study detected no difference in implant or prosthetic movement between nonpegged hydroxyapatite porous and spherical alloplastic nonporous implants. No controlled studies were retrieved that investigated whether pegging porous implants improves prosthetic movement. Several case series indicate that patients with pegged hydroxyapatite implants have some degree of improved prosthetic motility. Longitudinal cohort studies show that sclera-covered hydroxyapatite implants have higher exposure rates than sclera-covered silicone implants, and unwrapped porous polyethylene implants have higher exposure rates than unwrapped acrylic implants. There are numerous case series that document a wide range of implant exposure rates in patients with various enucleation implants. It is difficult to compare complication rates among implant types because patient populations vary, surgical techniques differ, and follow-up periods are often limited. CONCLUSIONS: Based on one randomized clinical trial, spherical alloplastic nonporous and nonpegged porous enucleation implants provide similar implant and prosthetic motility when they are implanted using similar surgical techniques. Coupling the prosthesis to a porous implant with a motility peg or post appears to improve prosthetic motility, but there are few available data in the literature that document the degree of the improvement. There is a widely variable incidence of porous implant exposure, but certain surgical techniques and the type of wrapping material seem to reduce the exposure rate. Additional research is needed to document the long-term incidence of complications related to porous enucleation implants and associated surgical techniques. This includes the use of wrapping materials and what procedural modifications, both surgical and prosthetic, are most effective in reducing these complications.     

Muscle pedunculated scleral flaps. A microsurgical modification to improve prosthesis motility

Orbital implants following enucleation are able beyond all doubt to compensate volume adequately and improve artificial eye motility. In recent decades progress has been made concerning implant material. Nevertheless, in most designs wrapping with homoplastic or alloplastic materials is advocated. In this report a microsurgical concept is presented to avoid wrapping material and at the same time to improve prosthesis motility in a hydroxyapatite-silicon implant. In a retrospective study two groups of patients (15 individuals each) were compared concerning prosthesis motility 6 months after surgery. In group 1 the horizontal and vertical eye muscles were sutured cross-wise in front of the implant (as done since the introduction of this type in 1989). In group 2 autologous muscle pedunculated scleral flaps were dissected microsurgically and used to cover the anterior part of the porous hydroxyapatite component of the implant. There was a highly significant better prosthesis motility and so far no complications concerning implant coverage in this second group. The authors consider the use of muscle pedunculated sclera to be a modification to improve the cosmetic outcome which may also reduce the postoperative complication rate in enucleation surgery.     

Polytetrafluoroethylene as a wrapping material for a hydroxyapatite orbital implant

PURPOSE: Porous coralline hydroxyapatite orbital implants have been used with great success in anophthalmic sockets. We used a substitute for donor sclera as a wrapping tissue. METHODS: Orbital implants were wrapped with polytetrafluoroethylene (PTFE) instead of homologous donor tissue in five patients after enucleation. RESULTS: The postoperative course was uneventful in three cases. Complications occurred in two cases: one with implant exposure, and one with severe implant infection leading to its eventual removal. CONCLUSIONS: PTFE is inferior to other wrapping tissue.     

Exposure rates of wrapped and unwrapped orbital implants following enucleation.

PURPOSE: To compare the complication rate of porous polyethylene orbital motility implants with solid acrylic implants following enucleation and identify possible risk factors. METHODS: The authors retrospectively reviewed the charts of a total of 117 consecutive enucleations performed at the University of Illinois at Chicago between March 28, 1994, and May 28, 1999. Data obtained included patient demographics, surgical indication, implant type, attending surgeon, surgical technique, and any reported complications. The primary outcome was presence or absence of implant exposure at the final recorded visit. RESULTS: Of the 117 identified cases, 29 were eliminated due to insufficient follow-up data. Of the 88 remaining cases, 48 patients received porous implants and 40 received solid acrylic implants. Implant exposure developed in four cases. All exposures occurred in unwrapped porous polyethylene implants (n=2) or porous polyethylene implants wrapped in absorbable material (n=2). All exposures occurred in patients younger than 18 years of age, and 75% occurred early after trauma-associated enucleation surgery. CONCLUSIONS: The exposure rate of porous polyethylene implants in this study (9%) was found to be comparable to published rates for hydroxyapatite implants. There were no exposures of unwrapped solid acrylic spheres. Unwrapped porous implants in pediatric patients or following trauma-related enucleation may represent an increased risk for postoperative implant exposure. Absorbable wrapping of porous implants may carry the same risk for exposure as no wrapping. Porous implants wrapped in durable material appear to be as safe as solid acrylic spheres.     

Survival after primary enucleation for choroidal melanoma: changes induced by the introduction of conservative therapies

BACKGROUND: Most uveal melanomas are currently treated by eye-preserving radiotherapies. However, for melanomas of the largest size or with initial complications, enucleation remains the reference treatment. Enucleation is called primary when it is proposed as the only local treatment option for a melanoma. There is very little literature on the use of primary enucleation after the introduction of conservative treatments. Our main goal was to evaluate the survival of melanoma patients treated by primary enucleation since the introduction of proton-beam therapy in France in 1991. METHODS: All melanoma patients undergoing primary enucleation in our department between 1991 and 2002 were included in this retrospective study. The 5-year melanoma-specific survival rate was calculated using the Kaplan-Meier method. The multivariate prognostic analysis was performed using the Cox proportional hazards model. RESULTS: Forty patients, representing 8% of all patients with choroidal uveal melanoma diagnosed and followed up in our department during an 11-year period, were included in the study. No patient was lost to follow-up. The 5-year melanoma-specific survival rate was 31.45% (SE: 7.8) after primary enucleation. Significant prognosis factors in the multivariate analysis were: tumor thickness > 12 mm (p = 0.03), anterior margin of the tumor involving the iris (p = 0.018), and presence of epithelioid cells (p = 0.02). CONCLUSIONS: The very low survival rate reported reflects the evolution of primary enucleation, which is currently indicated only for melanomas with the worst prognosis. The knowledge of current post-enucleation survival rates represents an essential achievement for both correct assessment of conservative therapies and patient counseling.     

Porous orbital implants, wraps, and PEG placement in the pediatric population after enucleation

PURPOSE: To investigate complications of various porous orbital implants and wrapping materials in the pediatric population after enucleation. DESIGN: A retrospective, comparative, nonrandomized study. METHODS: Between November 1992 and November 2006, patients younger than 15 years old were collected for study participation. They underwent enucleation with porous orbital implants primarily or secondarily at National Taiwan University Hospital. The authors used the hydroxyapatite (HA), Medpor, and Bioceramic orbital implant. The HA implant was wrapped with four different materials: donor sclera, Lyodura, porcine sclera, and Vicryl mesh. A part of HA implants and all bioceramic implants were wrapped with Vicryl mesh, added anteriorly with scleral patch grafts. All Medpor implants were unwrapped. RESULTS: Forty-seven cases had more than a two-year follow-up. The exposure rates according to implants and wraps were: donor sclera-wrapped HA (two of nine, 22%), porcine sclera-wrapped HA (three of three, 100%), Vicryl mesh-wrapped HA (one of five, 20%), and unwrapped Medpor (one of four, 25%). No exposure was found in four Lyodura-wrapped HA implants, and 22 Vicryl mesh-wrapped HA and Bioceramic implants with anteriorly scleral coating. The exposure rate was lower in cases with implants wrapped by our method and Lyodura than in those with implants wrapped by other materials (P < .001). Of 47 patients, 20 (42.5%) were fitted with peg-coupled prostheses and all had good prosthetic movements subjectively. CONCLUSIONS: Different types of implants and wraps resulted in various exposure rates in the pediatric population. The modified wrapping technique may prevent porous implants from exposure in children.     

Coralline hydroxyapatite as an ocular implant.

Fifty patients received a coralline hydroxyapatite sphere as a buried integrated ocular implant after enucleation or evisceration surgery. The surgical technique is described and the results discussed. All patients obtained final prosthetic motility superior to that possible with simple spherical methylmethacrylate implants. After a follow-up of 2 to 27 months (mean, 10.4 months) there have been no cases of migration or extrusion. Complications have been minimal and easily managed. The hydroxyapatite implant appears to offer excellent cosmetic reconstruction without the unacceptable infection and extrusion rates seen with other integrated implants.     

Scleral wrap increases the long‐term complication risk of bone‐derived hydroxyapatite orbital implants

Background: This study was prompted by previous findings that suggested that scleral wrapping increased the rate of complications following insertion of bone‐derived hydroxyapatite orbital implants and compared the long‐term results of implants inserted with and without scleral wraps. Methods: This retrospective case series reviewed the long‐term outcomes of 159 patients who had undergone enucleation with insertion of a bone‐derived hydroxyapatite orbital implant at Dunedin Hospital between 1977 and 2006. Implants were inserted with and without scleral wraps in 85 and 74 cases, respectively. Follow up was 0.5–27.5 years (mean 8.2 years) for the whole series and 9.7 years for the sclera group and 6.7 years for the group without sclera. Patient details were obtained from theatre records, case note review, patient interview and examination, interview of patient relatives and family general practitioner records. The main outcome measures were the rates of minor or major complications and their treatments and outcomes. Results: Twenty‐seven cases (17%) suffered minor complications of limited implant exposure that either healed spontaneously, with implant drilling or wound resuturing and 11 cases (7%) suffered major complications requiring explantation. Of 38 patients with postoperative complications, 31 (82%) had scleral wraps compared with 7 (18%) without sclera (P < 0.001; OR 5.14, 95% CI 2.00–14.78). Conclusion: Bone‐derived hydroxyapatite orbital implants inserted without scleral wrap were associated with better clinical outcomes and a lower rate of long‐term complications. It is therefore recommended that these implants be inserted without a scleral wrap.     

Porous polyethylene (Medpor) orbital implant. Prospective study of 75 primary implantations

PURPOSE: To examine the incidence of orbital complications in patients who underwent primary placement of a porous polyethylene implant (Medpor) after enucleation. MATERIAL AND METHOD: Prospective non randomized case series of 75 consecutive patients in whom a porous polyethylene (PP) spherical implant wrapped with homologous sclera was implanted after enucleation. RESULTS: The mean age at the time of enucleation was 42.7 years (range, 1.4 to 80 years). The histopathological diagnoses after enucleation included uveal melanoma in 28 patients, retinoblastoma in 11 patients, phthisis bulbi in 23 patients, neovascular glaucoma in 5 patients, endophthalmitis in 3 patients, ruptured traumatic globe in 2 patients, microphthalmos in two patients, and medulloepithelioma in one patient. Thirty-four patients (45%) had had prior ocular surgery. The prosthesis was fitted after a mean interval of 4.5 weeks (range, 3 to 10 weeks). After a mean follow-up of 20 months (range, 3 to 33 months), there was one case (1%) of conjunctival dehiscence with material exposure secondary to massive postoperative orbital hemorrhage 2 weeks after enucleation. There was no case of orbital cellulitis, implant extrusion, or significant inflammatory response. No PP implant was drilled for peg placement. DISCUSSION-CONCLUSIONS: The anteriorly wrapped porous polyethylene orbital (Medpor) sphere appears to be well tolerated by all age groups with no major complication in primary implantation after enucleation.     

珊瑚羟基磷灰石Ⅱ期眶内植入

目的：观察眼球摘除后羟基磷灰石眼座二期眶内植入的修复疗效。方法：用珊瑚多孔羟基磷灰石作为二期眶内植入物共253例。结果：随访6个月-15个月均获得良好的效果。并发症少,未发现眶内感染,植入物排出移位现象,结论：珊瑚羟基磷灰石并发症少,是目前眼球摘除后的良好眶内充填材料。     

Enucleation with on-the-table evisceration. Is it a good technique?

PURPOSE: To evaluate the surgical technique of enucleation followed by an "on-the-table evisceration" and placement of a hydroxyapatite orbital implant wrapped by the patient's own sclera for the treatment of blind phthisis painful eyes. PATIENTS AND METHODS: In this single-center retrospective study, 50 consecutive patients undergoing an operation using the same surgical technique, between April 1993 and November 1999, were studied. Patients underwent enucleation, then the eyeball was eviscerated "on the table". The patient's own cleaned sclera was used to wrap a hydroxyapatite orbital implant, the posterior pole of the sclera was placed at the anterior pole of the implant. Conjunctival breakdown, sphere size, conjunctival discharge, the first signs of sympathetic ophthalmia motility, and cosmetic results were analysed. RESULTS: After an average follow-up of 13.3 months few complications were encountered: 4 cases (8%) of inclusion cyst and 3 cases (6%) of discharge. The implant placed had a diameter of 18 mm, 20 mm, 22 mm in, respectively, 48%, 48%, and 4% of the eyes. The prosthesis motility was good, medium, and poor in, respectively, 33 (78.6%) cases, 8 (19%) cases, and 1 (2.4%) case. The prosthesis tolerance was good, medium, and poor in respectively 86%, 10%, and 4% of the cases. CONCLUSION: The surgical technique of enucleation followed by an "on-the-table" evisceration and autologous sclera wrapping a hydroxyapatite implant is an easy procedure. It allows, on phthisis eyeballs, the placement of a large orbital implant for good cosmesis results, without major complications.