Histological and Morphological Change of Implanted Reinforcement Gore-Tex(R) in Nasal Dorsum of Rabbit / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: For nasal augmentation surgery, several materials have been used. Porous material, expanded polytetrafluoroethylene (Gore-Tex(R)) contains numerous pores which allow stability of the implant, but this advantage has been tempered by unpredictable outcomes. The purpose of this study is to evaluate morphological and histological changes of reinforced Gore-Tex(R) in the rabbit model. MATERIALS AND METHOD: Twenty New Zealand white rabbits were used. The reinforced Gore-Tex(R) block was implanted in the nasal dorsum. According to the duration of implantation, rabbits were divided into four groups such as 1, 3, 6 and 12 months. The animals were grossly examined with respect to the status of the Gore-Tex(R). We evaluated the three-dimensional size of the implants over time and used light and electron microscopy to investigate the histological changes associated with the whole tissue blocks. RESULTS: Grossly, none of the implants was lost or extruded and there was no evidence of wound infection. Diminution rates of thickness, width and height in the implants were respectively 16.7%, 7.5%, and 3.5%. Histologically, the growth of connective tissue was observed in all specimens and internodal space was decreased by connective tissue ingrowth as time goes on. Neovascularization was observed in the groups for which duration was longer than 6 months, and degenerative changes were also observed in the groups over 6 month of implanted duration. CONCLUSION: The reinforced e-PTFE should be carefully trimmed because of the possibility of decreasing size over time. And additional studies are needed to further investigate the stability of Gore-Tex(R).

Surgical repair of recurrent cervical cancer at a skin incision site with using a Gore-Tex(R) Patch: A case report / 대한산부인과학회지

Recurrence of cervical cancer at a skin incision site is uncommon. We met a patient who received an incomplete operation for cervical cancer and she was transferred to our hospital. When she underwent the first operation she was misdiagnosed as having a benign uterine mass and she received an abdominal total hysterectomy. But the postoperative pathologic finding was cervical cancer. Therefore she was then referred for postoperative cisplatin-5FU concurrent chemo-radiotherapy. Five months after the concurrent chemo-radiotherapy, one solitary metastatic mass was found in the abdominal scar. We performed wide excision. The fascia defect at the excision site was so wide we could not perform the primary closure. Therefore, we used a polytetrafluoroethylene (Gore-Tex(R)) patch as a fascia substitute and we reconstructed the abdominal wall with a fasciocutaneous flap. Then she received cisplatin concurrent chemo-radiation therapy.

Reccurent Foreign body Granuloma after Gore-tex(R) Removal in Rhinoplasty

PURPOSE: Infection, foreign body reaction and decreased volume of implant are common complications after augmentation rhinoplasty with Gore-tex(R) implant. The author experienced two cases of recurrent foreign body granuloma in the patients who underwent Gore-tex(R) removal because of infection after augmentation rhinoplasty. and treated them with complete removal of Gore-tex(R). METHODS: Case 1: A 49 year-old female visited our clinic for recurrent foreign body reaction on nasal dorsum and tip area. The patient underwent augmentation rhinoplasty with Gore-tex(R) 3 years ago and implant was removed due to infection 9 months ago. Excision of the granuloma was performed and a piece of foreign body suspicious to be a Gore-tex(R) implant debris was detected under the subcutaneous pocket. The implant fragments were removed and nasalis muscle rotation flap was performed to cover the lesion. The specimen was proved to be Gore-tex(R) in histological study. Case 2: A 31 year-old-male with recurrent foreign body granuloma on the nasal tip area visited our clinic. 10 years ago, the patient had augmentation rhinoplasty with silicone implant and then, he underwent revisional rhinoplasty five times including nasal implant removal, which was performed 9 months ago. The authors excised the granuloma and found a small sized foreign body suspicious to be a Gore-tex(R) implant debris under the granuloma. The foreign body was excised and identified to be Gore-tex(R) in histological study. RESULTS: In both cases, the lesions were healed without any complications and there were no evidences of recurrence up to 6 months of follow-up. CONCLUSION: The Gore-tex(R) is known to be weak against mechanical force. These properties of Gore-tex(R) make it difficult to remove the implant completely. In the patient who have infection after augmentation rhinoplasty with Gore-tex(R), the operator should take care to perform the complete removal without remaining fragment of the implant.

Valproic Acid Effect in Nerve Regeneration Using Gore-Tex(R) Tube Filled with Skeletal Muscle

As the large defect of peripheral nerve occurs, the autologous nerve graft is the most ideal method but it has many limitations due to donor site morbidities. Various materials have been developed for the nerve defect as the conduits, but none of these materials is satisfactory. Among them, Gore-Tex(R) tube seems to be one of the most ideal nerve conduit materials at peripheral nerve defect. Many researches have focused on finding the neurotrophic factors. It is recently demonstrated that Valproic acid(VPA) has an effect of axonal regeneration as a neurotrophic factor without enzymatic degradation and toxicity problems. The purpose of this study is to evaluate the effect of VPA on the nerve regeneration at the peripheral nerve defect. A 10 mm gap of rat sciatic nerve was made and Gore-Tex(R) tube filled with biceps femoris muscle was placed at the nerve defect site. We let the rat take VPA as drinking water in experimental group and did not give VPA to the control group. We estimated the results as electrophysiologic and histological aspects for 16 weeks after the surgery. The nerve conduction velocity, total myelinated axon count, myelin sheath thickness and mean nerve fiber diameter significantly increased in VPA-treated experimental group when compared to the control (p < 0.05). From the above results, we conclude that VPA promotes the nerve regeneration at the peripheral nerve defect site. It is suggested that Gore-Tex(R) tube filled with skeletal muscle and VPA administration may be a good substitute for autologous nerve graft.

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.

The Availability of Gore-Tex(R) Tube as Nerve Conduit at the Peripheral Nerve Defect

When a large peripheral nerve defect occurs, an autologous nerve graft is the most ideal method of recinstruction. But an autologous nerve graft has many limitations due to donor site morbidities. Many previous focused on finding the ideal nerve conduit. Among them, Gore-Tex(R) has several advantages over other conduits. It can be manipulated to a suitable size, does not collapse easily, and it is a semi- permeable material that contain pores. A round shaped nerve can be newly formed because of its smooth inner surface. The purpose of this study was to evaluate the availability of Gore-Tex(R) tube as a nerve conduit at the peripheral nerve defect in the rat sciatic nerve. The 10 mm nerve gap was made in each group. A Gore-Tex(R) tube filled with skeletal muscle was inserted and autologous nerve graft was harvested, respectively. In the experimental group, we placed a 0.5mm thickness, 30micrometer pored, 1.8mm in diameter and 14mm length tube with skeletal muscle inserted inside. In the control group, the nerve gap was inserted with a rat sciatic nerve. We estimated the results electrophysiologically and histologically to 16 weeks postoperatively. Results in the nerve conduction velocity, total myelinated axon count, myelin sheath thickness and mean nerve fiber diameter, the experimental group was substantially lower than that of the control group, but the statistic difference was not significant (p<0.05). The morphology was very similar in both groups, microscopically. From the above results, We conclude that Gore-Tex(R) qualifies as an ideal nerve conduit. It is suggested that Gore-Tex(R) tube filled with skeletal muscle may, substitute for an autologous nerve graft.

Problems of Expanded Polytetrafluoroethylene (Gore-Tex(R)) in Augmentation Rhinoplasty

Augmentation rhinoplasty is one of the most popular aesthetic procedures in Asians. Numerous alloplastic implants have been used, however alloplastic implants may cause many problems in nasal and perinasal areas because of thin soft tissue cover. For these reasons, an ideal implant should be nonpalpable, readily exchangeable and biocompatible. Among these alloplastic implants, Gore-Tex(R) is a polymer of carbon bound to fluorine composed of solid nodes connected by very fine fibers. It has been reported that this material become permeated and surrounded by mature connective tissue, forming a strong supporting envelop for the material, yet the implant is easily removed because of limited tissue ingrowth. Since it's development, Gore-Tex(R) has found many applications in the field of facial plastic and reconstructive surgery. From November, 2001 to December, 2002, Gore-Tex(R) implants were removed from 17 patients due to several problems such as; decreased dorsal height, tip deformity, chronic inflammation. The implants were very hard to remove and coinciding injury of the surrounding tissue were inevitable. An analysis of the length and thickness changes in these removed implants was made. The results showed, decrease in length and thickness with a volume loss averaging, 46.3% in 45x4.0mm implants, 49.3% in 50x5.0mm implants. In view of the experiences of 17 cases of Gore-Tex(R) implants in rhinoplasty, we have concluded that Gore-Tex(R) implants were structurally unstable, fibrovascular tissue ingrowth into pores were minimal, the implants were very hard to remove and the implants caused a postoperative volume reduction. Therefore, Gore-Tex(R) use in augmentation rhinoplasty should be approached with caution.

Reconstruction of Lateral Capsular Ligament of Temporomandibular Joint with E-PTFE(Gore-tex(R)) Patch

The lateral capsular ligament of temporomandibular joint(TMJ) prevents mandibular condyle from lateral displacement in case of fractures related with condyle. When the condylar fracture with lateral extracapsular displacement occurs, open reduction and reconstruction of capsular ligament must be considered. However, many patients exhibit limitation of functional movements of the TMJ after such surgery. This may be a result of myositis, myospasm, fibrosis of bilaminar zone, adhesion of TMJ capsule. When the joint problem occurs, non surgical treatment must be attempted firstly. But if it fails, the surgical reconstruction must be considered. We reconstructed the lateral capsular ligament of TMJ with E- PTFE(Expanded Polytetrafluoroethylene, Gore-tex(R)) patch after removing scar tissues and adhesions. This surgical method showed improvements in movement as well as the pain of the joint. No side effect has detected from occlusion for about 2 years. There was no foreign body reaction or irritation to the capsule, since E-PTFE was biologically inert. We believe that the E-PTFE patch could be used as primary material of capsular ligament of TMJ reconstruction, insertion material in high tensioned capsule and reinforcement material in weakened capsule.

Experience with use of Expanded Polytetrafluoroethylene(Gore-tex(R)) in Cosmetic Facial Surgery

To date, for facial soft tissue augmentation, numerous implant materials have been used, including autogenous, homogenous, and alloplastic grafts. Among these, the porous material, Gore-tex(R) has a pore (0.5-30 microns, average 22 microns) which allows sufficient but limited soft tissue ingrowth to anchor implants, but not so much to make removal difficult or destructive to adjacent structures. In addition, this material has some advantage: non-carcinogenic, non-allergic, less capsule formation and reduced chance of infection due to high vascularity. In the past years Gore-tex(R) has found multiple applications in facial plastic and reconstructive surgery. However this alloplastic material can be associated with potentially severe complications and side effects such as soft tissue reaction, infection, extrusion, exposure, etc. There have been also adverse criticism of Gore-tex(R) : relative difficulties in postoperative removal, in carving implant, higher infection and extrusion rates in scarred tissue and thicker implant as well as postoperative volume reduction. In order to analyze results depending on the implantation site, the presence of scar on recipient site, thickness and type of implant, a retrospective chart review of 56 patients(69 cases) was undertaken of all patients who underwent facial soft tissue augmentation with Gore-tex(R) graft from November 1998 to November 2001 in a wide variety of situations. All cases were categorized as either primary(normal recipient site) or secondary(scarred recipient site) cases and the thickness of each graft used in millimeters was recorded. Postoperative follow up revealed a stable implant material with no major complications relating to the graft material and no differences in developing complications according to the implantation site, the presence of scar, thickness and type of implant. All patients were highly satisfied with their results.

The Experimental Study on the Usability of Gore-Tex(R) as an Extraocular Muscle Expander

Expander procedure is a newly developed extraocular muscle weakening technique which has several advantages such as good control of resection margin, easy reoperation, rare postoperative muscular paresis. For the study of usability of Gore-Tex(R) as a muscle expander, fifteen rabbits received expander procedure with Gore-Tex(R) in right eye and silicone retinal band in left eye. At postoperative 1, 3, 5, 7, 12 weeks, histopathologic examination was performed. There was no significant difference in inflammatory reaction in both groups. Inflammatory reaction decreased with time in both groups. In Gore-Tex(R) expander group, muscle regeneration from cut end was observed at the 3rd postoperative week and fibroblast ingrowth into the expander was observed at the 5th postoperative week. These findings were more prominent with time. Adhesion of expander to underlying sclera was not observed in both groups. It is concluded that expander procedure using Gore-Tex(R) will be a new and useful surgical method for the extraocular muscle weakening procedure.

Histopathologic Findings after Experimental Penetrating Keratoplasty using Dacron-Gore-Tex(R) Combined Graft in Rabbits: Treatment of Corneal Perforation using Synthetic Materials. Report II

The purpose of this study is to evaluate the histopathologic findings after experimental penetrating keratoplasty using Dacron-Gore-Tex(R) combined graft in rabbits and the clinical efficacy of the treatment of corneal perforation using synthetic materials. Type A which used end to end fixation showed better results than that of type B which used intralamellar fixation and, however, complications and instability of graft occured in most eyes of both types. Type C which modified type B and reduced the thickness of intralamellar portion of graft showed relatively good results compared with type A and B, but there was still instability. Leakage from anterior chamber in early postoperative period prior to fiibrovascular invasion into graft was considered as the main cause of instability of graft. Therefore we performed type D which emphasized on preventing leakage, and well-maintained anterior chamber without extrusion of graft, that is, the best result among all 4 types was observed until 6 weeks postoperatively. Although further study is needed, we think that Dacron-Gore-Tex(R) combined graft can be a good substitute for the management of corneal perforation.