Otoplasty with High Density Polyethylene Implant (MEDPOR(R))

PURPOSE: The key points of treatment of cryptotia are the elevation of invaginated ear helix and the correction of deformed cartilage. Prevention of stabilized cartilage contouring from returning to the previous state is also important. The authors carried otoplasty by modified Onizuka's method or Ohmori's method that conchal cartilage graft or high density polyethylene implant(MEDPOR(R)) graft served as fixation after spreading posterior aspect of adhered antihelix and a splint for prevention of recurrence of cartilage deformities. The aim of this study is to reveal the availability of the high density polyethylene implant(MEDPOR(R)) graft for the correction of cryptotia. METHODS: We have repaired 17 cryptotic deformities using cartilage graft from cavum of concha(12 cases) or high density polyethylene implant(5 cases) for correction of deformed cartilage. We investigate the operative time, complications, and satisfaction of postoperative ear shape on both autogenous cartilage graft group and high density polyethylene implant graft group. RESULTS: There was 1 case of reinvagination on autogenous cartilage graft group. Implant exposure was occurred on high density polyethylene implant graft group, as 1 case. These were statistically no differences between autogenous cartilage graft group and high density polyethylene implant graft group to the satisfaction of ear shape. CONCLUSION: High density polyethylene implant (MEDPOR(R)) present an alternative to autogenous material as they allow of fibrovascular ingrowth, leading to stability of the implant and decreased infection rates. The correction of deformed cartilage by using the high density polyethylene implant(MEDPOR(R)) is a good option for the treatment of cryptotia.

Effects of Medpor(R) Sheet as Substitute for Tarsus in Eyelid Reconstruction

PURPOSE: To report a simple surgical technique for rebuilding the palpebral tarsal plate using a Medpor(R) sheet. The formation of a palpebral tarsal plate is very important in the reconstruction of the eyelid. Transplantation of cartilaginous tissue is often necessary to create the palpebral tarsal plate. However obtaining enough cartilaginous tissue is difficult. CASE SUMMARY: Eyelid reconstruction and surgical resection of each lesion was attempted on two patients clinically diagnosed with basal cell carcinoma and sebaceous gland carcinoma between August, 2006 and November, 2007. Reconstruction was performed using a modified Cutler-Beard method or the sebaceous gland carcinoma that occurred in the upper eyelid, and a modified Tenzel semicircular rotational flap procedure was used or the basal cell carcinoma that occurred in the lower eyelid. For the reconstruction of tarsus, 0.45 mm Medpor(R) sheet was used. Complications, such as shortage of eyelid movement, dragging of eyelid or unstable eyelid margin, did not occur after the operations in either subject. In the case of the upper eyelid reconstruction, the eyelid became stiff at the early stage, but the condition improved after 6 months. CONCLUSIONS: The reconstruction of the palpebral tarsal plate using a Medpor(R) sheet is considered an effective and safe technique for the reconstruction of an eyelid.

Upper Eyelid Reconstruction Using the Medpor(R) Sheet and Median Forehead Flap

PURPOSE: To report the upper eyelid reconstruction with median forehead flap and Medpor(R) sheet implant following full-thickness eyelid defect resulting from tumor resection. CASE SUMMARY: A 65-year-old woman was examined at our hospital for a recurrent mass on the right upper eyelid. A wide tumor excision with a 3 mm margin and an eyelid reconstruction procedure were performed after a frozen section biopsy revealed a malignancy. The full-thickness eyelid defect was reconstructed with a median forehead flap as a substitute for skin and muscle and a Medpor(R) sheet substituted for tarsal plate was sutured with a lower conjunctiva flap for posterior lamella. The histopathology diagnosis of the lesion showed a well-differentiated squamous cell carcinoma. The lower conjunctiva was separated at 2 weeks after surgery, and then the median forehead flap detached from the upper eyelid skin at 8 weeks after surgery. One year postoperatively, there was no evidence of a wound infection and an exposure of the Medpor(R) sheet. The eyelid had a good cosmetic contour and the movement of the eyelid during blinking was natural. CONCLUSIONS: The use of a Medpor(R) sheet as a substitute for a tarsal plate in reconstructive procedures of the upper eyelid defect shows cosmetic and functional success.

Correction of Frontal Bone Defect in Cleidocranial Dysostosis with Porous Polyethylene(Medpor(R)): A Case Report

PURPOSE: Cleidocranial dysostosis is a rare hereditary disorder affecting bones that develop by intramembranous formation. The typical features include excessive growth of transverse diameter of the skull, hypoplastic clavicles, low height and characteristic facial features. METHODS: A 28-year-old female patient visited by frontal area depression. The diagnosis was performed by computed tomographic study and radiographic imaging. The patient had widely opened anterior fontanelle, partial fused metopic suture, multiple wormian bone and supernumenary impacted teeth. Under the coronal incision, we exposed depressed frontal area and corrected with Medpor block carving. RESULTS: Postoperatively frontoparietal skull was aestheticlly improved and satisfied the patient. CONCLUSION: Authors report a case of cleiodocranial dysostosis who underwent correction of abnormal skull shape by Medpor(R) insertion.

The Role of Endothelial Progenital Cells and Fibrin on Vascularization and Stability in Orbital Implant

PURPOSE: The effects of endothelial progenitor cells (EPCs) and fibrin on fibrovascular growth into porous polyethylene orbital implants (Medpor(R) sheet) were investigated using stem cells. METHODS: EPCs were separated from human adipose fat tissue for culture. Fluorescence-activated cell sorting (FACS) was used to identify the phenotype and to analyze the purity of EPCs cultivated from human adipose tissue. Processed Medpor(R) sheets were inserted in each quadrant of the subcutaneous fat layer under the dorsal surface of 20 anesthetized athymic nude mice, using sterile methods. Medpor(R) sheets processed with endothelial progenitor cells and fibrin were inserted into the two top quadrants, a Medpor(R) sheet processed with fibrin was inserted in the lower right quadrant, and an unprocessed Medpor(R) sheet was inserted in the lower left quadrant of each mouse. The mice were sacrificed on the seventh day. The adhesiveness and blood vessel formation were quantified by weight and the number of blood cells within the Medpor(R) sheets. Hematoxylin and eosin (H&E) and toluidine blue stains were used to analyze fibrovascular and cell growth within the Medpor(R) sheets. RESULTS: The sheets processed with EPCs and fibrin were heavier and contained more white and red blood cells (p<0.001) than the other sheets. The sheets processed with fibrin alone were heavier (p<0.01) and contained more blood cells (p<0.001) than the unprocessed sheets. The degree of vessel formation and tissue adhesiveness was greatest in the group of Medpor(R) sheets processed with EPCs and fibrin. The sheets processed with fibrin only had greater tissue adhesiveness and fibrovascular proliferation than the unprocessed Medpor(R) sheets. CONCLUSIONS: Endothelial progenitor cells and fibrin applied to Medpor(R) sheets improve fibrovascular proliferation and tissue adhesiveness. When both are applied together, a synergistic effect is seen.

Internal Fixation of Medpor(R) Implant for Prevention of Enophthalmos in Posteriorly Extended Orbital Floor Fracture

PURPOSE: The purpose of this study is to evaluate the effectiveness of internal fixation method of Medpor(R) implant with BioSorb(TM)FX screw which is used for prevention of enophthalmos in posteriorly extended large orbital floor fracture. METHODS: From Jun. 1997 to Dec. 2007, 21 patients who were diagnosed with posteriorly extended large orbital floor fractures were classified into two groups. One group(n=11) had undergone reduction surgery with regular Medpor(R) sheets without any fixation method, while the other group(n=10) had their Medpor(R) sheets fixed with the BioSorb(TM)FX screws. The two groups were evaluated by comparison of their enophthalmos degree and effectiveness. RESULTS: In the non-fixation group, six patients had enophthalmos preoperatively and three of them showed persistent enophthalmos postoperatively. In postoperative CT examination, displacement of Medpor(R) implant with soft tissue impaction into maxillary sinus was observed in the patients. In the screw fixation group, three patients had enophthalmos preoperatively, but none of them suffer from complication such as residual enophthalmos, soft tissue impaction, muscle entrapment or optic nerve compression postoperatively. CONCLUSION: Internal fixation method of Medpor(R) implant with BioSorb(TM)FX screw on the medial surface of orbital floor provides firm stabilization of implants and surrounding soft tissues and can be an effective option especially when postoperative implant displacement or malposition was expected.

Alternative Use of Inferior Blow-out Fracture Reduction with Urinary Balloon Catheter

PURPOSE: The operative treatment for blow-out fracture involves restoration of intra-orbital soft tissue and bony structural integrity. There are several methods for reconstruction of inferior blow out fracture. We report reduction of inferior blow-out fracture with urinary balloon catheter in comparison with Medpor(R) using group to complication rate. METHODS: A retrospective study was performed on 67 patients who underwent inferior orbital blow-out fracture reconstruction with Medpor(R) implant or urinary balloon catheter following between 2003 and 2006. Hospital records were reviewed especially for preoperative and postoperative enophthalmos, diplopia, extraocular muscle movement limitations, and hypoesthesia between Medpor(R) implant group and balloon catheter using group. RESULTS: There was no significant statistical difference between both groups on incidence of postoperative complications of enophthalmos, diplopia, extraocular muscle movement limitations, and hypoesthesia. Postoperative infection, ectropion were absent in both groups. CONCLUSION: The use of urinary balloon catheter is simple, fast and inexpensive. Urinary balloon catheter is an alternative and reliable use for reduction of inferior orbital blow-out fracture.

Repair of Large Posterior Inferior Wall Fracture Using Medpor(R) Channel Sheet Implant

PURPOSE: To evaluate the effectiveness of a Medpor(R) (porous polyethylene) channel sheet in large posterior and inferior orbital wall fracture repair. METHODS: We retrospectively analyzed the clinical features and postoperative outcomes of 52 patients who had undergone orbital wall reconstruction with a Medpor(R) (porous polyethylene) channel sheet between February 1999 and December 2005. RESULTS: Among 52 patients, 44 were men and 8 were women, with average age of 30.8 years and average follow-up period of 6.3 months. The surgery was performed on average at15 days after injury in 44 patients, except for in 8 reoperated cases. Miniplate or microplate fixation on the orbital rim with a Medpor(R) channel was required in all 52 patients for large posterior inferior wall fracture. Preoperatively, 43 patients had symptomatic diplopia, which resolved completely in 32 patients and decreased in 11 following surgery. No patients had induced diplopia or exacerbation of preoperative diplopia, except the primary gaze of 2 patients with hypertropia remained, requiring strabismus correction. The mean difference in preoperative enophthalmos between both eyes was 2.8 mm, which improved to 0.8 mm at the last follow-up. There were no instances of orbital infection, implant exposure or migration, or visual loss during follow-up. CONCLUSIONS: Medpor(R) channel implant provided optimal reconstruction of large inferior orbital wall fracture with posterior defect that lacked structural support.

The Survival of Freely Grafted Orbital Fat on Porous Polyethylene Orbital Implants in the Rabbit

PURPOSE: To investigate the long term survival of orbital fat grafted on a Medpor(R) implant as a method of preventing porous polyethylene orbital implant (Medpor(R)) exposure in anophthalmic sockets. METHODS: In one orbit in each of 8 rabbits, a small amount of retrobulbar orbital fat was grafted between the anterior surface of the Medpor(R) implant and overlying conjunctiva, during the enucleation and Medpor(R) implantation procedure. Two rabbits were sacrificed at 2, 4, 8 and 12 weeks postoperatively and grafted orbital fats were examined by light microscopy. RESULTS: Grafted orbital fat was well-maintained at 2 and 4 weeks, postoperatively. However, fat amounts were significantly reduced at 8 weeks, and viable fat was barely visible at 12 weeks. CONCLUSIONS: In rabbits, orbital fat grafted on Medpor(R) implants was gradually resorbed, and the fat-occupied volume was not maintained.

Comparison of Physical & Histological Change of Alloplastic Implants after Implantation in Rat

Augmentation rhinoplasty is one of the most popular aesthetic procedure in Asians. Numerous alloplastic implants have been used until now, but no accurate comparative analysis about the implant materials has been reported yet. This study in animal model was designed to determine the safety and effectiveness of various implant materials in augmentation rhinoplasty. The 15 x 15 x 2 mm sized square shaped plate of Gore-Tex(R), silicone rubber, and 15 x 15 x 1.5 mm sized Medpor(R) were implanted under panniculus carnosus of the abdomen wall of rat. And tissue specimens including the implant and surrounding soft tissue were obtained by en bloc excision in 6 months after implantation. The implants were estimated in weight and volume, and also the specimens were examined grossly and microscopically. The results revealed that increase of average weight 26.9%, decrease of average volume 55.4% in Gore-Tex(R) implant, increase of each average weight and volume 62.6%, 8.7% in Medpor(R) implant and very slight increase of both average weight and volume 4.7%, 1.1% in silicone rubber implant. Grossly, the Gore-Tex(R) was deformed, Medpor(R) was strongly adherent to surrounding soft tissue and the silicone rubber was well encapsulated and easily peeled off. Microscopically, silicone rubber showed foreign body reaction slightly and there were no inflammatory responses in all alloplastic implants. In our study, silicone rubber showed very proper alloplastic features for augmentation rhinoplasty due to causing no inflammatory response, no physical change, and no deformity.

Reconstruction of anterior temporal depression after the coronal approach

A Case of Candida Infection after Porous Polyethylene (Medpor(R)) Orbital Implantation

PURPOSE: To report a case of candida infection after Medpor(R) orbital implantation. METHODS: A 51-year-old man was admitted complaining of painful swelling and discharge about 3 years after orbital Medpor(R) implantation. External examination revealed signs of infection and exposure of the implant. Medpor(R) was surgically removed. In laboratory studies, white colony was detected in blood agar, potato dextrose agar, and CHROMagar. Automatic identification with yeast standard test revealed Candida parapsilosis. RESULTS: Six months after surgery, the wound had healed well. In addition, cosmesis was acceptable with the artificial eye, except mild superior sulcus deformity. CONCLUSIONS: Although rare, fungal infection of the implant should be suspected when there are the long standing signs of infection and exposure after orbital Medpor(R) implantation.

Medpor(R)-using Reconstruction of the Orbital Floor Defect Caused by the Maxillary Sinus Mucocele: A Case Report

Mucoceles of the paranasal sinuses are benign, locally expansile cysts filled with mucus and lined by the mucoperiosteum of the involved sinus. Orbital symptoms are characteristic in symptomatic maxillary sinus mucoceles, and patients initially consulted ophthalmologists for eyeball displacement, diplopia, proptosis, enophthalmos, epiphora, and rarely decreased visual acuity. Recently, we experienced a case of maxillary sinus mucocele with the destruction of the orbital floor. The mucocele was treated by marsupialization via intranasal and transantral approach, and the large defect of orbital floor was successfully reconstructed using high-density porous polyethylene (Medpor(R), Porex Surgical Inc, College Park, GA). Accurately positioned Medpor implant was observed in the orbital floor after 48 months postoperatively.

Correction of Superior Sulcus Deformity and Enophthalmos with Porous High-density Polyethylene Sheet in Anophthalmic Patients

PURPOSE: Superior sulcus deformity is the main cosmetic problem in anophthalmic patients. Many methods of correcting enophthalmos have been reported, especially in patients with orbital wall fracture. The purpose of this study is to review the long term results of effectiveness in superior sulcus deformity correction by subperiosteal Medpor (R) sheet implantation in anophthalmic patients. METHODS: Subperiosteal Medpor (R) sheets were used in 11 eyes of 11 anophthalmic patients. To estimate the effectiveness, photographs were taken and exophthalmometric value with their own prosthesis using Hertel exophthalmometer was measured in all patients before and after surgery. RESULTS: The overall cosmetic results in superior sulcus deformity were 'excellent' in 3 (27.3%), 'good' in 6 (54.5%), 'fair' in 2 (18.2%). The overall results in enophthalmos were 'excellent' in 3 (27.2%), 'markedly improved' in 4 (36.4%), 'slightly improved' in 4 (36.4%). Most patients had a marked increase in orbital volume, except two patients. They received irradiation treatment in early childhood so showed unsatisfactory results in both superior sulcus deformity and enophthalmos. CONCLUSIONS: Subperiosteal Medpor (R) sheet implantation is considered to be a reliable and safe procedure without serious complication and with an excellent cosmetic results.

Surgical Treatments in the Late Infection of Hydroxyapatite Orbital Implants

PURPOSE: We experienced six cases of late infection of the hydroxyapatite (HA) orbital implant treated with surgical procedures. METHODS: Exposures of the HA and pyogenic granulomas around conjunctival dehiscence helped us to confirm infections of the HA orbital implants. Infections were not controlled by medical therapies so the HA implants were exchanged by silicone implants in all cases. Finally, the silicone implants were replaced by Medpor(R) after the inflammation had been controlled. Dermis fat graft was also performed in two cases due to insufficient conjunctival sac. RESULTS: Infections of HA orbital implants occurred at 62 to 106 months postoperatively. Staphylococcus aureus and Pseudomonas aeruginosa were cultured from removed implants. All cases show successful outcomes during 12 to 42 months after Medpor(R) implantations. CONCLUSIONS: Infections of peg-inserted HA orbital implants occurred after five years due to exposure of HA orbital implants. To replace infected HA implants with Medpor(R) implants is considered a functionally and aesthetically effective therapeutic method.

Comparative Observation of Barrier Sheet and Nonbarrier Sheet Medpor(R) Inserted on Orbital Floor in Rabbits

The purpose of this study was to determine the histopathologic change of Medpor(R) implant for the case of orbital floor reconstruction in the rabbit model. Two types of Medpor(R)(barrier sheet and nonbarrier sheet) were used for the reconstruction of orbital floor in 30 rabbits. In 1 month and 6 months postoperatively, the histopathologic changes were observed with light microscope and forced duction test was performed. None of the implants were lost or extruded and there was no evidence of wound infection, hematoma, or seroma formation. None of cases showed positive in force duction test. Orbital tissue ingrowth was not observed in the barrier sheet Medpor(R) implant group, however, it was observed in the nonbarrier sheet Medpor(R) implant group. This study supports that the barrier sheet Medpor(R) may more suitable than nonbarrier sheet Medpor(R) for reconstruction of the fractured orbital wall.

The Clinical Outcome of Endoscopic Transnasal Conjunctivodacryocystorhinostomy Using MEDPOR(R) Coated Tear Drain

PURPOSE: Tube displacement, consisting of protrusion, spontaneous loss, and intrusion, is the most common cause of failure in conjunctivodacryocystorhinostomy with Jones tube. Recently, MEDPOR(R) Coated Tear Drain was designed to minimize these complications. We evaluate the surgical outcome of conjunctivodacryocystorhinostomy with MEDPOR(R) Coated Tear Drain. METHODS: Primary conjunctivodacryocystorhinostomy or revision surgery using MEDPOR(R) Coated Tear Drain was done on 23 eyes of 23 patients and the development of displacement was monitored. Thirteen patients suffered from habitual displacement of Jones tube and underwent revision surgery, while the remaining 10 underwent primary conjunctivodacryocystorhinostomy. RESULTS: During 12-month follow-up after surgery, tube intrusion was noted in one among the 23 patients. Protrusion or spontaneous loss of tube did not develop. CONCLUSIONS: The use of MEDPOR(R) Coated Tear Drain may be very effective not only for revision surgery in patients who have suffered from habitual displacement of Jones tube but also on primary conjunctivodacryocystorhinostomy.

Craniofacial Contouring Using Porous Polyethylene(Medpor(R)) Implant

Among the alloplastic implants, porous polyethylene (Medpor(R)) is one of the ideal materials for augmentation of the craniofacial region. The interconnecting open pore structure of Medpor(R) allows for tissue ingrowth which promotes host integration and prevents migration. The firm nature allows easy carving and prevents collapsing. Because of these advantages, Medpor(R) has been well used for reconstruction of orbital wall. From March 1994 to December 2002, 27 patients were performed the craniofacial contouring surgery using Medpor(R). Thirteen patients were male, 14 were female. The causes of operations were as follows: trauma, 16; cosmetic, 8; and others, 3. The sites of implant were as follows: frontal, 8; temporoparietal, 6; zygoma, 5; maxilla, 3; mandible, 3; and periorbital, 2. The follow up period was 6 months to 48 months with an average of 12 months. The implants were placed into the subperiosteal plane, and fixed with titanium screws. After fixation, the final contouring was performed by carving with a knife or shaving with a high speed bur. There was no infection. All implants were in place, and there was no extrusion. All patients were satisfied at the results of the operation. The irregular margin of implant was felt in 3 cases. However, reoperation was not performed in these patients because of minimal irregularity. In conclusion, Medpor(R) allows ingrowth of soft tissue without adverse tissue response, and there is no donor mobidity. Implanted Medpor(R) were not absorbed or distorted. With these advantages, Medpor(R) could be one of ideal implants for craniofacial contouring.

The Clinical Study of the Exposure of Implant after Evisceration

PURPOSE: To determine the factors leading to the exposure of porous spherical orbital implants (Hydroxyapatite or Medpor(R)) after evisceration. METHODS: A retrospective analysis of evisceration cases with porous spherical orbital implant performed between January 1998 and August 2002 (n=104). Forty-five patients underwent evisceration with Hydroxyapatite implantation and 59 with Medpor(R) implantation. We analyzed the exposure rate by sex, age, size of implant, kind of implant, with or without drilling, preoperative condition of eyeball, and surgeon. RESULTS: Mean follow-up period was 18.1 months. The sex, age, size of implant, drilling, and preoperative eyeball condition showed no statistically significant difference on exposure rate, but Medpor(R) implant showed a higher exposure rate than Hydroxyapatite. The exposure rate of implant between orbital implants was mostly influenced by surgeon. CONCLUSIONS: The exposure rate of implant was mostly influenced by surgeon's factor, indicating that delicate operative technique for evisceration is necessary.

The Correction of Mild Hemifacial Microsomia: Polyethylene Implantation, Lateral Cortectomy, and Osseous Genioplasty

Hemifacial microsomia is a condition most frequently associated with facial asymmetry. Authors have experienced eighteen patients with mild hemifacial microsomia who were classified as type IA and IB. For the correction of mandibular asymmetry, mandibular augmentation was performed on the mandibular angle of the affected side using mandibule shaped porous high-density polyethylene(Medpor(R)) in thirteen patients. Reduction mandibuloplasty was performed on the mandibular angle of the normal side using lateral cortectomy in four patients, and genioplasties were used in 2 patients. Osseous genioplasty(n=10), buccal fat removal(n=4), augmentation rhinoplasty(n=2), and onlay bone graft(n=1) as ancillary procedures were simultaneously executed. Except for 4 patients in whom the implants were removed due to exposure and infection, all other patients were satisfied with a more symmetric contour of their face. The results were clinically evaluated through ordinary scale method and photogrammetric analysis. The mean score was rated 'good' as 12.5 points, and the mean bigonial distance index and the mean gonion-midsagittal distance index were 105.20%(p=0.035) and 100.65%(p=0.368), respectively, which meant a more symmetry of the lower face. In minor asymmetry of the mandible in cases of hemifacial microsomia, augmentation with cautions of the affected side, reduction with lateral cortectomy of the mandible in the non-affected side, and an even osseous genioplasty can provide the patient with a more symmetric lower face.