Alloplastic cranioplasty

The use of alloplastic implants for cranial reconstruction has a long history with numerous materials used with varying degrees of success. Currently, three different alloplastic alternatives are widely used, methymethacrylate, hydroxyapatite, and metal. Each has its own advantages and indications in contemporary cranioplasty. When employed with good surgical technique and in the appropriate patient, each material can have good clinical outcomes.     

Immediate autogenous cartilage grafts in rhinoplasty after alloplastic implant rejection

BACKGROUND: It is accepted in rhinoplasty that complications are more common with alloplastic implants than with autografts. There is little guidance in the literature on how to deal with the cosmetic and/or functional problems that follow alloplastic implant rejection. The conventional advice has been to remove the allograft and not place any graft at the same time. The present article presents our experience treating allograft rejection and immediately repairing any structural defect with autografts. OBJECTIVE: To demonstrate that immediate nasal reconstruction using autogenous cartilage is a good technique when an alloplastic material has to be removed because of rejection, inflammation, or infection. DESIGN: A retrospective analysis of outcome for a case series. METHODS: A retrospective review of the management of 8 patients who presented to 2 tertiary referral centers with alloplastic implant rejection following rhinoplasty. In 7 cases, the alloplastic implant had to be removed because it had migrated and caused a foreign body reaction; in 1 case, the implant had caused a bacterial infection. RESULTS: In all 8 cases, the nasal deformity that followed the removal of the allograft was so marked that the nose was immediately reconstructed with autogenous cartilage. The patients all made a good recovery after immediate reconstruction, although skin changes associated with the alloplastic implant remained after a mean follow-up of 3 years 3 months. CONCLUSION: The use of autogenous cartilage is a good option for nasal augmentation immediately after the removal of an alloplastic implant.     

A Method of Augmenting the Cheek Area Through SMAS, subSMAS, and Subcutaneous Tissue Recruitment During Facelift Surgery

BACKGROUND: As the human face ages, there is a depletion of fat that occurs in the submalar region. Various techniques such as fat transfers, fillers, alloplastic implants, and composite rhytidectomies have been used to augment this area in the past. OBJECTIVE: To describe a technique that augments the submalar areas during facelift surgery without the use of fat transfer, fillers, alloplastic implants, or a risky composite technique. METHOD: An oval is scribed over the depressed submalar areas preoperatively. During facelift surgery, a fusiform area is scribed over the SMAS. This fusiform is scribed so that the medial end is directed at the center of the submalar depression, and the lateral end is toward the posterior earlobe. A defect is created within the lateral aspect of the fusiform, but not the medial portion. The fusiform is subsequently closed with a 2-0 Ethibond suture using three horizontal mattress sutures and two interrupted sutures. Upon closure of this defect, SMAS, subSMAS, and subcutaneous tissue overlying the SMAS are recruited into the submalar defect by the simple phenomenon of dog-ear formation. Additionally, there is a component of frank elevation of the tissues inferior to the medial aspect of the fusiform and submalar space. RESULTS: The aforementioned technique has been performed on 123 patients over 7 years and has resulted in consistently good improvement in the submalar space. The procedure is not difficult to learn, and good results can be achieved with initial cases. The learning curve was not found to be steep, with good results being achieved quickly. CONCLUSION: Depression of the submalar space plays a significant role in creating an aged face. In the past, various fillers and/or alloplastic implants have been used to augment this region. A low-risk method is described that mobilizes SMAS, subSMAS, and subcutaneous tissues into the submalar space through the phenomenon of dog-ear formation after fusiform closure.     

Alloplasty in injuries of the Achilles tendon

Methods of alloplastic restoration of tendo calcaneus (Achilles) after different injuries with the application of tendinous transplants are described. An analysis of clinical observations for 25 years in 112 patients is presented. The methods used for operative interventions and preparation of plastic materials gave good and satisfactory results in most of the patients (97.3%).     

Open capsulotomy for capsular contracture: A new procedure for the prevention of recurrence

Capsular contracture is a frequent complication after breast augmentation with alloplastic implants. A technique has been developed to correct this contracture, performed through the previous operative scar. Use of a portion of the matured capsule wall as petal flaps appears to be a contributing factor in the success of this procedure. Open capsulotomy has been performed on 23 patients with good results in 20. The procedure should be performed at least 6 months after augmentation mammoplasty has been performed.     

Experience with alternative material for nasal augmentation

In the last six years, 101 Proplast 11 implants were used for correcting various nasal deformities. The time of observation ranged from one to six years. During this period, four implants were removed: two because of late postoperative infection and two others because of trauma. Our experience indicates that Proplast 11 is a good alternative in cases that require alloplastic implants to correct an existing nasal deformity.     

Musculotendinous alloplasty in patients with infantile cerebral palsy

A special alloplastic material was used in 20 patients aged from 7 to 16 for substituting or making up a deficient function of muscles, ligaments and tendons after preliminary elimination of all fixed contractures and deformities. A conclusion is made of the application of the special alloplastic material not only for patients with infantile cerebral paralysis but also in other aspects of surgery especially for children.     

Biomaterials for use in frontal sinus obliteration

Although fractures of the frontal sinus are infrequent (2-15% of victims of facial trauma), because of their proximity to the brain and eyes, the consequences of their management may have a significant impact on the patient. For frontal sinus injuries that affect the nasofrontal ducts or posterior wall, obliteration is indicated. Although frontal sinus surgery has been documented since 1750, a consensus as to the best material for obliteration has not been achieved. The particular autogenous and alloplastic materials for use in frontal sinus obliteration will be the focus of this review, with particular attention paid to assessing their physical properties, advantages, disadvantages, and complications. While numerous new alloplastic materials show promise for frontal sinus obliteration, autogenous fat remains the most popular and most frequently used material with the longest history of use, and it is versatile and reliable.     

Ureter replacement operations

Reviewing the recent literature and own clinical experiences, the possibilities of replacement of the ureter by isolated bowel segments, alloplastic prostheses and xenoplastic or autoplastic transplants are shown and evaluated. Although used only in single cases, the interposition of the appendix vermiformis into larger defects of the ureter seems to render the best results. The interposition of bowel segments in the urinary tract has been applied more often, the results, however, have been variable. Numerous modifications have been proposed. The use of alloplastic prostheses and free autologic transplants have--up to now--led to no satisfying long-term results. Only human deep frozen umbilical veins as xenotransplants seem to be suitable as ureter replacements.     

Precoating of alloplastic materials with living human fibroblasts—a feasibility study

Background: The use of alloplastic materials such as polypropylene and polyester has reduced the recurrence of abdominal wall hernias. Concomitantly, new problems have arisen such as inflammatory response against the implanted material and the development of enteric fistulas in case of direct contact of the bowel to polypropylene and polyester. A precoating of the PP with collagen and other absorbable materials seems to reduce the incidence of adhesions and fistulas. The aim of this study was to show the technical feasibility of a precoating of polypropylene with living human fibroblasts and to investigate the growth properties of the cells under these conditions in vitro.Methods The textile structure of three different alloplastic materials is described (SurgiPro^®, TycoHealthcare; Parietene3 PP1510^®, Dallhausen; VIPRO II^®, Ethicon Endosurgery). Enhanced Green Fluorescence Protein (EGFP) transduced human foreskin fibroblasts (KiF5) were seeded onto these different alloplastic materials. Proliferation was analyzed by FACS analysis of Ki67 expression. The coating process of the whole mesh area was observed over time with UV-light microscopy, immunostaining, and scanning electron microscopy (SEM). The expression of collagen type I and III was investigated by immunostaining.Results The three alloplastic materials used were knitted fabrics with different textile structures. KiF5 colonized the entire alloplastic material within 4–6 weeks. Cells were proliferating, as detected by Ki67 expression. SEM showed surface ruffles and long cellular extensions, indicating an active cell metabolism. Light microscopy and SEM suggested that the cells modify the apolar surface by deposition of extracellular matrix components before colonization.Conclusion Our study shows the feasibility of precoating of polypropylene meshes with living human fibroblasts and opens the possibility for clinical use in the future.     

Medpor外耳再造术皮肤覆盖方案的临床研究

目的:本文通过比较几种不同的支架外皮肤覆盖方案,探索一种手术效果稳定可靠的合成材料支架外耳再造方法。方法:48例先天性小耳畸形,应用Medpor支架行全外耳再造术,支架外软组织覆盖材料分别为单纯乳突区扩张皮肤1例、颞顶筋膜瓣加植皮25例、乳突区扩张皮瓣加颞顶筋膜瓣22例,观察比较应用不同覆盖材料耳再造后支架外露发生率、再造外耳外形轮廓、表面皮肤颜色质地。结果:临床应用48例,随访1至6年,应用单纯乳突区扩张皮瓣覆盖者1年内耳支架完全外露;应用颞顶筋膜瓣加植皮者再造耳廓外形及轮廓优良,但大部分病例再造耳廓皮瓣不同程度色素异常;应用乳突区扩张皮瓣及颞顶筋膜瓣联合覆盖者再造外耳形态及轮廓均优良,且表面皮瓣颜色质地与周围皮肤和对侧外耳皮肤一致,美容效果最佳。结论:应用乳突区扩张后皮瓣及颞顶筋膜瓣双层组织瓣的软组织覆盖方案可以满足Medpor再造外耳的外形、轮廓及皮色的需求,是一项安全稳定的手术方案,综合效果优于颞顶筋膜瓣加植皮方案,而单纯应用乳突区扩张皮瓣的方案不适用于Medpor外耳再造术。因此推荐在选用Medpor耳支架行全外耳再造治疗Ⅲ度先天性小耳畸形时,优先选用颞顶筋膜瓣联合乳突区扩张皮瓣的软组织覆盖方案。     

Treatment of abdominal wall eventrations associated with abdominoplasty techniques

An experimental and clinical study using alloplastic materials (Marlex and Prolene mesh) for repairing large defects of the abdominal wall is reported. A defect was created in the experimental model to simulate an anatomical disarrangement of the musculo-aponeurotic-fascial complex of the abdominal wall and the surgical correction of this deformity. Macroscopic and microscopic observations of the operated area were done to demonstrate the good integration of the surrounding tissues with the mesh.In a clinical study, 16 patients, presenting large eventrations of the abdominal wall, were surgically treated using Marlex or Prolene mesh to reinforce the abdominal wall. Two techniques of abdominoplasty, vertical and horizontal, were performed on these patients, according to the location of previous scars. The advantages of using alloplastic materials to reinforce the abdominal wall and the cosmetic results of both abdominoplasty techniques are discussed.     

Orbital and optic nerve trauma

The ability to measure orbital volume expansion and correlate this with later enophthalmos has advanced radiological assessment of patients with orbital floor fractures. Attempts have also been made to classify orbital floor fractures on the basis of their configuration on CT scan and to correlate this with outcome in terms of ocular motility. A small subset of relatively undisplaced floor fractures with tight entrapment of tissues occurring most commonly in young patients has been identified, and early surgical intervention has been recommended for these. The range of alloplastic materials available for orbital rim and wall fractures has increased, and complications related to various alloplastic implants continue to be reported. Optic nerve trauma has received considerable attention but remains a difficult management area. Recent literature on this subject shows no definite benefit for optic nerve decompression or high dose corticosteroids, although no prospective randomized study has been possible.     

A monolateral TMJ replacement under intraoral endoscopic assistance for jaw osteomielitis: a modified approach

Alloplastic replacement has become a valid treatment for TMJ end-stage disease. The Alkayat and Bramley pre-auricular approach combined with the submandibular incision are the current surgical approaches for TMJ surgery. The present study shows a modified approach using intraoral endoscopic assistance. A female patient affected by jaw osteomielitis with condylar detachment was treated with total left TMJ alloplastic replacement combined with a right TMJ arthroplasty. No subamandibular incision was performed and, subsequently, the risks for permanent or temporary damage to the marginalis mandibulae nerve and surgical submandibular scar were avoided. Postoperative CT-Scan evidenced a good prosthesis position. No complications occurred after two years of follow-up.     

Comparative investigation of alloplastic materials for hernia repair with improved methodology

Background: A variety of alloplastic materials are used for hernia repair. We discuss the long-term stability and possible shrinkage of these materials. In the past, measurement of pore sizes was used to study the physical properties of alloplastic meshes. The aim of this study was to evaluate the measurement of pore sizes with regard to its correlation to possible mesh alteration. Methods: The water absorption of different polypropylene (PP) and polyester (PE) mesh materials under defined conditions was studied. For shrinkage studies, meshes were stored in formaldehyde, distilled water, saline solution, trypsin solution, urea solution, and hydrogen peroxide. The measurement of the relation between material and pore was evaluated to investigate the potential shrinking and enlargement processes. This material–pore index (MPI) before as well as 1, 7, and 14 days after incubation was measured. Results: In comparison to measuring single pore sizes, MPI determination is the more efficient method to evaluate the possible shrinking or enlargement processes of alloplastic materials. With this technique, incorrect determination of pore sizes due to the dynamic textile structure of meshes and to shrinkage or enlargement, is excluded. All tested alloplastic materials showed an insignificant increase in water absorption under the condition of rehydration up to 0.4%. We did not observe variances in the material in shrinking or enlargement. Conclusions: MPI was found to be more reliable than measuring single pores to investigate possible external influences on polymer materials. Biomaterials such as PP and PE proved to be absolutely inert under various in vitro conditions.     

Chin region: management of grooves and mandibular hypoplasia with alloplastic implants

Using just a small number of alloplastic extended mandibular implants can fulfill more than 95% of the needs of the facial plastic surgeon in chin and prejowl augmentation to restore balance to a patient's jawline. Current chin implants are artistically designed to impart good form and fit and give significant improvement for a somewhat uncomplicated procedure.     

The prosthetic bladder

Summary Bladder reconstruction may be required in a variety of pathological conditions, including bladder cancer, irradiation cystitis, interstitial cystitis, tuberculosis, and various congenital anomalies. Currently, bladder reconstruction is done with an autogenous bowel segment. Use of a total prosthetic bladder as an intracorporeal urinary reservoir has been an elusive goal for many decades. Many investigational and a few clinical trials have been performed in an attempt to develop a near-nornal bladder prosthesis utilizing alloplastic materials. To date the ideal prosthetic bladder has not been developed. However, cumulative experimental studies suggest that many, perhaps all, of the ideal functional characteristics of a total prosthetic bladder are possible. Basically, two different alloplastic models have been investigated.     

Alloplastic ureter substitution and limitations in clinical application. A status analysis

Operative ureteral replacement with the patient's own body tissue or by reconstructive ureteral surgery is indicated relatively often. The operative methods applied vary: they include pelvic flap pyeloplasty, caudal transposition of the kidney, interposition of the small intestine, trans-ureterostomy, calico-ureterostomy, of bladder flap transplantation and autotransplantation of the kidney. When the indications are correctly observed with reference to the kind and location of the ureteral lesion all these methods are successful. The methods of alloplastic replacement of the ureter, in contrast, have lost clinical importance and should be performed only in rare, isolated cases, mainly as a short-term solution. Possible indications are a poor general condition in patients for whom alloplastic ureteral replacement is the only alternative to permanent nephrostomy and malignant tumours requiring immediate irradiation, which cannot be postponed until definitive wound healing has taken place following a plastic operation. It is important that problems of biocompatibility have now been largely overcome. Segmental ureteral replacement with alloplastic materials is not possible, however, and the functional difficulties with urinary transport have not been solved in the long term, even in models with pumps and reflux-preventing mechanisms.     

Experiences with the combined use of PMMA (polymethyl-metacrylate-Palacos) and Gentamycin in the management of osteomyelitis (author's transl)

Two new alloplastic methods of filling bony cavities in osteomyelitis has been reported here. Palacos mixed with Gentamycin has been used to fill cavities at 15 different sites in 14 patients. Gentamycin- PMMA beads made by Merck were used in 15 patients. Both methods resulted in primary healing in 8-8 cases. When a solid block of PMMA was used healing was found in 4 cases and was not in 3. When GPMMA-beads were implanted 2 cases healed and 5 failed. The condition did not deteriorate postoperatively at any patient. The time of observation has been too short to draw any major conclusion from this study, which was intended to be a preliminary publication only.     

Considerations in the use of biologic grafts and alloplastic implants in facial plastic and reconstructive surgery

Surgical changes in the contour of soft tissue and bone of the craniomaxillofacial structures may require use of a biologic graft or alloplastic implant. Autologous materials are preferred; however, the harvesting procedure, donor site, and its associated morbidity are the disadvantages of using autografts. There are numerous types of alloplastic implants and they all differ in how they interact with host tissues. Factors such as implant texture, ability to integrate with host tissues, and rate of resorption all influence the overall success of different implants. In this article, we discuss some considerations in the use of biologic grafts and alloplastic implants in facial plastic and reconstructive surgery.