Microtia Reconstruction

Wilkes, Gordon H. M.D.; Wong, Joshua M.D., M.Sc.; Guilfoyle, Regan M.D.

doi: 10.1097/PRS.0000000000000526
CME
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Learning Objectives: After reviewing this article, the participant should be able to understand: 1. The epidemiology and genetics of microtia. 2. Refinements in surgical technique for microtia. 3. Outcomes of treatment. 4. Challenges in treatment selection, hearing restoration, surgical training, and tissue engineering.

Summary: Microtia reconstruction is both challenging and controversial. Our understanding of the epidemiology and genetics of microtia is improving. Surgical techniques continue to evolve, with better results. Treatment selection continues to be controversial. There are strong proponents for reconstruction with costal cartilage, Medpor or a prosthesis. More realistic models for teaching surgeons how to do the procedures are becoming available. Our approach to hearing rehabilitation is changing. Better solutions using percutaneous and implantable devices are under evaluation to help both unilateral and bilateral microtia patients. Tissue engineering will offer some exciting new treatment possibilities in the future.

Related Video Content is available online.

Edmonton, Alberta, Canada

From the Institute for Reconstructive Sciences in Medicine, Covenant Health Group, Faculty of Medicine and Dentistry, Misericordia Community Hospital.

Received for publication September 18, 2013; accepted May 28, 2014.

Disclosure: The authors have no financial interest to declare in relation to the content of this article.

Related Video content is available for this article. The videos can be found under the “Related Videos” section of the full-text article, or, for Ovid users, using the URL citations published in the article.

Gordon H. Wilkes, M.D., University of Alberta, No. 174 Meadowlark Health Center, 156 Street and 87 Avenue, Edmonton, Alberta T5R 5W9, Canada, gordon.wilkes@albertahealthservices.ca

Article Outline

Ear reconstruction continues to be challenging and not without controversy. There have been several CME and review articles published in this Journal and others, beginning with the excellent two-part series by Drs. Beahm and Walton in 2002.1–9 This series in particular gives an in-depth overview of the field of ear reconstruction at the time, and much is still very relevant. When used with this overview, together they provide an excellent understanding of the classic surgical techniques and their evolution. The goal of this CME article is to attempt to minimize repetition and present complementary new information. Most references have been published since 2005. This article in conjunction with these other reviews will give the reader an up-to-date understanding of the field of ear reconstruction and its areas of controversy.

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EPIDEMIOLOGY AND GENETICS OF MICROTIA

The cause and wide variation in prevalence (0.83 to 17.4 per 10,000 births) is still poorly understood.10 There is evidence for significant genetic and environmental contributions to microtia. There are more than 18 different microtia-associated syndromes with single-gene or chromosomal aberrations; however, there is no causal genetic mutation confirmed to date (Table 1). Mendelian inheritance is more common in syndromic and familial cases. Multifactorial or polygenic causes are more probable in sporadic cases. Microtia and oculoauriculovertebral spectrum share variable phenotypic expression, asymmetric facial involvement, right-side preponderance, male predilection, familial occurrence, microtia, tags, and pits. Craniofacial or hemifacial microsomia and Goldenhar syndrome are included in this spectrum. There are no accepted minimal diagnostic criteria for oculoauriculovertebral spectrum. Microtia and oculoauriculovertebral spectrum should each be considered a separate entity. Current hypotheses for microtia include (1) neural crest cell disturbance, (2) vascular disruption by means of several different mechanisms, and (3) altitude. There are a multitude of potential risk factors for the development of microtia (Table 2).

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SURGICAL TECHNIQUE FOR MICROTIA

First-Stage Modifications

Surgical creation of a three-dimensional costal cartilage ear framework has traditionally been considered the most challenging part of ear reconstruction.11–15 Classically, Brent harvested contralateral rib cartilage in an extraperichondrial plane. Nagata and Firmin both harvest cartilage from the ipsilateral chest. Nagata harvests in a completely subperichondrial plane and Firmin leaves the posterior perichondrium intact. Inadvertent pleural tear and chest wall deformity are less likely if perichondrium is left intact. Some surgeons feel there is better adherence of soft tissues to the framework if some perichondrium is left behind following carving; however, Nagata has not found this to be a problem. Modifications of the Brent and Nagata techniques particularly involving the tragal and conchal bowl regions continue to be reported. Included are three videos of costal cartilage ear framework creation. (See Video, Supplemental Digital Content 1, which displays the fabrication of the three-dimensional costal cartilage frame for microtia. This video is available in the “Related Videos” section of the full-text article on PRSJournal.com or, for Ovid users, at http://links.lww.com/PRS/B55. See Video, Supplemental Digital Content 2, which demonstrates how to carve an autologous rib cartilage. This video is available in the “Related Videos” section of the full-text article on PRSJournal.com or, for Ovid users, at http://links.lww.com/PRS/B56. See Video, Supplemental Digital Content 3, which shows the first stage in total auricular reconstruction. This video is available in the “Related Videos” section of the full-text article on PRSJournal.com or, for Ovid users, at http://links.lww.com/PRS/B57.)

Nagata adds an extra piece of cartilage under the framework to deepen the conchal bowl. Firmin adds an extra piece she calls the “surelevation” to give more stability and projection to the root of the helix and tragus. Chin et al.16 place an “extra cartilaginous cube” under the reconstructed tragus to give better projection and stability. They add a piece of cartilage to reconstruct the antihelix only if the thickness of the cartilage block is less than 5 mm. More recently, however, greater emphasis has been given to soft-tissue management to optimize the aesthetic result. Both Firmin and Marchac17 and Park16 provide an algorithm to help with the soft-tissue management of microtia. It has been shown that the subcutaneous pedicle in Nagata’s W flaps does increase the vascularity and decrease skin flap necrosis18,19 (Fig. 1). A gap is needed between the tip of the tragus and crus helicis in the carved framework to allow rotation around the pedicle during framework placement if the pedicle is left intact.

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Creation of a Postauricular Sulcus

Successful elevation of the ear framework and creation of a postauricular sulcus continues to be a challenge. Past approaches have included elevation and placement of a split-thickness or full-thickness graft only. Addition of a surgical stent to maintain projection has been used. The results were variable and often poor. New refinements appear to be beneficial, including adding a cartilage, bone, or alloplastic buttress.20–22 Alloplastic materials include bone cement and a hydroxyapatite ceramic. During elevation, Brent and Nagata leave some soft tissues on the elevated cartilage. Firmin exposes the entire posterior surface of the framework during elevation, leaving no soft tissues restraining the projection except for the posterior wall of the concha. The buttress requires vascularized coverage. Flaps described include a postauricular fascial flap, a temporoparietal fascial flap, and a superficial musculoaponeurotic system (SMAS) advancement flap. The flap from the mastoid is thicker than a temporoparietal fascial flap and most commonly covers just the buttress. The temporoparietal fascial flap can cover the complete raw surface of the posterior ear but is more involved to elevate. Endoscopic harvest has been reported, with fewer alopecia issues.23 Three different techniques of sulcus construction in microtia repair using a temporoparietal fascial flap, a retroauricular fascial flap from the mastoid region, and an SMAS advancement flap were compared, with no significant difference in outcome at 3 months. All included a cartilage buttress.24 The authors found the SMAS flap safe and easy to perform, and the procedure resulted in no secondary defects. It can be used for combined auricle and middle ear reconstructions, leaving the temporoparietal fascial flap available for complicated or revision cases. Rotation and advancement flaps have been described.25 The technique described by Chen et al. involves elevating a thin split-thickness skin graft from hair-bearing scalp in continuity with the full-thickness skin posterior to the ear to cover the temporoparietal fascial flap and avoid some visible scarring.26 Primary graft healing is essential in all techniques to prevent secondary wound contraction and loss of projection.

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Harvesting the Rib and Chest Wall Deformity

Critics of autogenous reconstruction cite chest wall deformity as a major drawback. Although still an issue, it appears to be less of a problem. Certainly, rib harvest including the perichondrium can result in chest wall deformity.27,28 Brent has advocated leaving a rim of sixth costal cartilage in situ to mitigate against this. Further steps are being taken intraoperatively to lessen the possible adverse effect of harvesting rib cartilage.29 Firmin recommends leaving the posterior perichondrium intact, stating that the “deformation at the donor site is minimal.” Kawanabe and Nagata30,31 leave the complete perichondrial sleeve intact and fill it or a Vicryl (Ethicon, Inc., Somerville, N.J.) sleeve with diced pieces of leftover cartilage. In a series of 273 patients, they reported no chest wall deformity. They also demonstrated regeneration of cartilage for future use. Siegert and Magritz32 described reducing chest wall morbidity by using patient-controlled analgesia for pain and a two-stage approach to hide the scar in the inframammary fold and to provide a full-thickness skin graft in women, and minimizing chest wall deformity by leaving perichondrium intact posteriorly and placing cartilage pieces in an absorbable sleeve to make “new” regenerated ribs.

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Soft-Tissue Expanders

The use of soft-tissue expanders in ear reconstruction can be helpful.33,34 The rationale is to attempt to provide complete skin coverage of a framework with no need for a fascial flap or skin graft. This approach provides thin skin with good color match. Barring a complication during expansion, the circulation is reasonable, as the skin has been delayed. Flaps can be designed in the expanded skin to provide coverage both anteriorly and in the posterior sulcus. Dealing with the capsule around the soft-tissue expander is controversial. It can be removed judiciously in areas if it is too thick or would affect adherence to the underlying structures. It is safest to leave it attached to any flaps created in the expanded skin. Soft-tissue expanders have also been used to expand under a temporoparietal fascial flap and scalp skin graft to provide coverage in challenging cases of anotia, failed autogenous reconstructions, and posttraumatic cases. This has included both ipsilateral pedicled and contralateral free vascularized temporoparietal fascial flaps. The potential for complications including skin necrosis and the added surgical stage are the major concerns with the use of soft-tissue expanders in ear reconstruction.35-37 Many complications are preventable with proper planning (Table 3). Higher rates of skin necrosis in acquired versus congenital cases have been reported. Expanding scarred skin provides inadequate skin in both quality and quantity for the delicate needs of ear reconstruction and should be discouraged.

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OUTCOMES

There is no commonly accepted means of assessing outcomes in ear reconstruction. Perceived results as judged by the patient, family, surgeon, and other observer can be quite different. The psychological outcome of treatment is as important as the patient’s overall recovery.

Microtia patients have been found to have a high prevalence of mood disorders, in particular, depression, interpersonal/social difficulties, and hostility/aggression.38 The child usually discovers they are different around the age of 3 or 4 years. The age of surgical intervention must be balanced against the potential for a good aesthetic reconstruction, as a poor result may have a long-term adverse psychological effect on self-esteem. The earlier the child is made aware of the deformation, the lower the prevalence of psychological disorders.

A standardized assessment tool (Glasgow Benefit Inventory) measuring health-related quality of life and a surgical outcome questionnaire have been effectively applied to ear reconstruction. Soukup et al. showed a significant improvement in health-related quality of life following autogenous ear reconstruction (Level of Evidence: Therapeutic, IV).39 The Glasgow Benefit Inventory demonstrated the greatest impact helping patients improve social interaction and relationships. Microtia with a syndrome had higher scores than isolated microtia. Age at the time of surgery had no effect. Chest scar color was more concerning than chest wall deformity. All had some form of successful chest wall reconstruction. Surprisingly, the surgeons and age-matched patients gave lower scores than the patients and parents. This contradicts opinions held by many skeptics that surgeons overestimate the quality of their results. Overall, there was a strong correlation between Glasgow Benefit Inventory and the surgical outcome scores. This study identifies where to improve the most to achieve greater health-related quality-of-life benefits. Others have shown similar results in both retrospective and prospective studies.40–42 Approximately 70 percent of patients felt the ear became part of the body image and the chest scar was acceptable. Interestingly, they revealed no difference in lifestyle and self-consciousness between autogenous and prosthetic treatment patients.

Braun et al. used the Glasgow Benefit Inventory, the Glasgow Children’s Benefit Inventory, and a questionnaire to study a group of patients who underwent reconstruction with porous polyethylene (Medpor; Porex Surgical, Inc., Newnan, Ga.) (Level of Evidence: Therapeutic, IV).43 There was again a high satisfaction rate with the aesthetics in 73 percent of adults and 85 percent of children. The Glasgow Benefit Inventory was elevated (21.2), indicating improvement in health-related quality of life, but was not as high as in the autogenous group (48.1).

The results of various autogenous techniques have recently been published by several authors.44–46 Although overall satisfaction is reported as high, there are certainly weaknesses in the methods of evaluation. When performed properly in an appropriate patient by an experienced surgeon, a satisfactory, stable ear reconstruction is possible in the majority of cases. Probably more important than the specific technique is the overall experience of the surgeon using an acceptable technique. Critics of autogenous reconstruction argue that the results published by the leaders in the field are only the best results and are not necessarily obtainable by other surgeons performing smaller volumes.

Controversy still surrounds the outcomes of a porous polyethylene alloplastic framework. Reinisch and Lewin published their series of 786 ear reconstructions from 1991 to 2008.47 Complications decreased when complete coverage of the framework with a temporoparietal fascial flap was used. A subgroup of 41 temporoparietal fascial flap patients with 12 years’ follow-up had a 2.7 percent fracture rate and a 7.3 percent exposure rate. Braun et al. presented their 65 temporoparietal fascial flap patients with a porous polyethylene framework.48 Twenty-eight patients (43.1 percent) had one or more revision operations, mainly for minor corrections. Only one required a major revision operation with partial explantation and reimplantation of porous polyethylene. Others have also reported success with porous polyethylene frameworks.49,50

Osseointegrated prosthetic ear reconstruction has also demonstrated high levels of success and patient satisfaction.51,52 Psychologically, the prosthesis becomes part of the body image in the majority of patients. Issues regarding prosthetic shape, color, means of attachment, and long-term implant stability are minimal. The major disadvantages of the osseointegrated approach are intermittent, usually mild, chronic soft-tissue problems; the need for continued maintenance; and repeated prosthetic reconstruction every 2 to 5 years. The implant failure rate in nonirradiated mastoid bone is low (2 percent), and loss of an implant does not necessarily mean inability to wear the prosthesis. The majority of patients (97 percent) were satisfied. Despite the soft-tissue problems, 94 percent would do it again and 97 percent would recommend it to other patients.

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TREATMENT SELECTION

Controversies remain regarding appropriate treatment selection for patients with major ear deformities. These include choice of framework (either costal cartilage or Medpor), surgical technique, or type of reconstruction (osseointegrated prosthetic or autogenous). Although we all have treatment biases, providing informed consent requires up-to-date knowledge of the various approaches and their appropriateness in a variety of clinical situations (Table 4).

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Autogenous

Although most surgeons would agree that a successful autogenous ear reconstruction is ideal, critics would argue that currently the aesthetic results are very inconsistent and often poor. Continued refinements in surgical techniques have resulted in better ear reconstructions (Fig. 2). The results are becoming more consistent and reproducible. Surgeons are more aware of the need for appropriate training and mentorship and a sufficient case volume to achieve consistent high-quality reconstructions. Most reconstructions currently performed are variations of the Brent or Nagata technique. Although they involve more complicated frameworks, Nagata-type procedures are becoming much more common (Table 5).

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Porous Polyethylene Framework (Medpor)

The role of porous polyethylene frameworks in our treatment selection remains controversial. There remains reluctance by many to use an alloplastic framework in an exposed area such as the ear. Proponents tout several advantages.47,49,50 A less controversial indication for the use of a porous polyethylene framework is the well-informed adult who does not want costal cartilage harvested or in whom it is too calcified and who does not want a prosthesis.

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Osseointegrated Auricular Prosthetic Reconstruction

Many plastic surgeons have difficulty understanding the role of this modality. Osseointegrated auricular prosthetic reconstruction is complementary to other approaches and provides a reasonable alternative in many cases with poor autogenous options (Figs. 3 and 4) or a poor autogenous result (Figs. 5 and 6). The use of an adhesive-retained prosthesis should not be considered a trial for an osseointegrated auricular prosthetic. Stability, positioning, skin breakdown, and confidence issues are completely different when using adhesives. Although some surgeons consider osseointegrated auricular prosthetic reconstruction a primary treatment of microtia, it is our opinion that a reasonable autogenous result is a superior long-term treatment choice (Table 6).

The onus is on the reconstructive surgeon to consistently provide a reasonable result with minimal morbidity and a high satisfaction rate (Table 7). As all these approaches can produce a satisfied patient, appropriate treatment selection and informed consent are some of the more important issues facing the surgeon in dealing with patients with major ear deformities. It is our experience that when all the options are presented, patients decide quickly how to proceed and very rarely change their mind.

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HEARING RESTORATION IN THE MANAGEMENT OF MICROTIA

The treatment of microtia should ideally involve reconstruction of the external ear and the restoration of normal hearing. Hearing impairment conceptually impairs a variety of social, cognitive, and developmental domains (Table 8). Hearing impairment in microtia is related to abnormalities of the external auditory canal, tympanic membrane, and middle ear. Attempts to reconstruct these structures have been fraught with difficulties such as frequent restenosis, infection, possible facial nerve injury, and scarring at the future site for auricular reconstruction.53 Hearing improvement has been variable and often poor. For these reasons, traditional thinking has been that further intervention is not necessary in unilateral microtia if there is normal hearing in the other ear. Yeakley and Jahrsdoerfer developed a computed tomographic grading system to predict patients with the most favorable hearing outcome from surgical intervention.54 Their results have proven difficult to replicate by most otologists. Also, comparative studies have shown that reconstructive middle ear surgery often requires the addition of an air-conduction hearing aid for hearing to be as good as that of a bone-anchored hearing aid alone.55 Siegert56 describes reconstruction of an ear canal and tympanic membrane as part of a three-stage microtia reconstruction. At the first stage, remnants of elastic auricular cartilage are packed densely into silastic mold to prefabricate the tympanic membrane. The external ear canal is also prefabricated with rib hyaline cartilage positioned in a silastic cylinder. These are stored in the subcutaneous thoracic wound. At the second stage, the ear framework is mobilized and the prefabricated tympanic membrane and external ear canal are placed. At the third stage, the canal is exteriorized and skin grafted. In a later publication, he states there was no restenosis of the canal but “reaching a near-normal hearing is not the rule.” There continues to be further investigation of surgical options.

Bilateral microtia patients have unique challenges for hearing restoration. The bone-anchored hearing aid (BAHA; Cochlear, Mölnlycke, Sweden; and Ponto; Oticon, Kongeballen, Denmark) Centennial, Col.) has been used since 1977, relying on bone conduction directly to the cochlea.57 It does not depend on a functioning middle ear or a patent canal. The most common practice is placement of a unilateral bone-anchored hearing aid in bilateral microtia and bilateral conductive hearing loss patients because a single hearing aid will stimulate both cochleae simultaneously. Recent evidence suggests that restoration of binaural hearing in fact results in greater stimulation of the cochlea and better directional hearing, space perception, and speech recognition in noise.58–63 Janssen et al. summarized these findings in a recent systematic review of 11 articles, concluding that bilateral bone-anchored hearing aid use results in improved hearing sensitivity and speech perception in the quiet, speech perception in noise, localization and lateralization, and patient perception of quality of life and overall sound quality.64 With this evidence, the verdict is still controversial but warrants expanding our therapeutic options to those with bilateral microtia and bilateral conductive hearing.

Thoughts are evolving in unilateral microtia patients with unilateral conductive hearing loss. Traditional thinking was that hearing on a single side was sufficient for speech development and hearing in education. A recent review of auricular reconstruction states that most children with unilateral microtia are born “adjusted to their monaural condition.”12 Studies suggest that the educational and cognitive developmental consequences of unilateral hearing loss warrant reevaluation of traditional practice and application of early treatment (Reference 66 Level of Evidence: Therapeutic, IV).65–67 Evidence indicates that there is both audiologic and subjective benefit when treating unilateral conductive hearing with a bone-anchored hearing aid.68–70 Further study is needed and treatment must be individualized. Giving patients the option of trying a cutaneous bone conduction hearing aid (i.e., Softband; Cochlear) in consideration of a permanent bone-anchored hearing aid is reasonable.71 Newer implantable hearing devices such as the Vibrant Soundbridge and Bonebridge (Med-El Corp., Innsbruck, Austria) and the Sophono System (Sophono Inc., Boulder, Colorado) are now being studied. Their long-term success in hearing restoration and effects on external ear reconstruction still require further evaluation.72–75

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Autogenous Ear Reconstruction and the Bone-Anchored Hearing Aid

There are obvious conflicting needs between the otologist and the reconstructive surgeon regarding placement of the bone-anchored hearing aid and the timing of surgery. Appropriate placement of the bone-anchored hearing aid is crucial both for hearing and to avoid scarring the site of future autogenous reconstruction (Fig. 7). The reconstructive surgeon would like the bone-anchored hearing aid placed posterior to its normal position. The otologist has concerns that the bone-anchored hearing aid will pick up sound from behind the patient not contributing to binaural hearing. A true team approach will alleviate both surgeons’ concerns. Studies addressing this are few.76 One promotes an optimal positioning of 6.5 to 7 cm posterior to the auditory meatus. We have performed implantation on patients both before and after autogenous reconstruction on average 5.6 cm from the pseudomeatus, with no difference in complications; however, both procedures were performed by the same surgeon (G.H.W.). The pediatric otologist would prefer that the bone-anchored hearing aid be sited and implanted as early as possible (presently, at approximately age 5 years) to optimize hearing development (Fig. 8). The plastic surgeon would prefer that the bone-anchored hearing aid implantation be performed after autogenous reconstruction (age 8 to 10 years) to not compromise the autogenous reconstruction (Figs. 9 and 10). The successful use of a bone-anchored hearing aid after a porous polyethylene reconstruction has also been reported.50

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LEARNING TO PERFORM EAR RECONSTRUCTION

Learning to perform ear reconstruction is a challenge.77–81 The major emphasis has been on learning to carve an ear framework from costal cartilage. More recently, the appropriate treatment of the soft tissues has been emphasized as a major contributing factor to the ultimate aesthetic result.

Some type of “observership” and then “giving it a go” has been a very common approach. The “I tried a few but gave up because my results weren’t very good” approach is no longer acceptable. Historical training methods have been poor or lacked realism. Although carving a vegetable, a piece of soap, or a piece of foam tests the artistic ability of the participant, cartilage from the sixth, seventh, and eighth ribs presents unique challenges of shape, form, and consistency, requiring careful intraoperative decisions that are often not reversible. Using cadaver cartilage is not practical because it is usually calcified, stiff, and brittle, not simulating the real surgical circumstance. Possible disease transmission is also an issue. The development of more realistic ear carving models (Figs. 11 through 13) are allowing surgeons to test their aptitude and gain experience before performing an actual reconstruction. (See Video, Supplemental Digital Content 4, which displays the tutorial and demonstration of a Nagata framework. This video is available in the “Related Videos” section of the full-text article on PRSJournal.com or, for Ovid users, at http://links.lww.com/PRS/B58.) Wilkes and Guilfoyle82 have produced a training app available at iTunesU, and Chen has a training model demonstration on YouTube.83 Firmin has also developed a “trainer” for learning ear reconstruction.14

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TISSUE ENGINEERING

Excellent reviews of the current state of tissue engineering in auricular cartilage reconstruction were published in 2012.84,85 Tissue engineering offers great promise for the future, but major hurdles remain.86–92 No material presently available, either autogenous or alloplastic, completely mimics the characteristics of auricular cartilage and can produce a normal appearing and functioning reconstructed ear.

The first problem is to create a three-dimensional scaffold onto which cartilage cells can anchor and subsequently grow. Biological scaffolds mimic cartilage extracellular matrix. Natural materials that have been explored include hydrogel, hyaluronic acid, chitosan, and collagen derivatives. Their limitations are poor mechanical strength, fast degradation, and antigenicity. Synthetic polymers have the advantage of being custom-made, whereby the biological and material properties can be controlled. However, they do elicit an immunologic response and lack the surface characteristics favoring cellular attachment and growth. Attempts are being made with surface modifications to optimize chondrocyte-scaffold interaction. Multiple polymers have been trialed and produced cartilage formation with variable loss of shape. Strides have been made in the precision design and construction of auricular molds based on the normal contralateral ear. The use of three-dimensional computer-aided design/manufacturing has helped make very accurate scaffolds. The designer can control porosity, shape, and permeability.

Chondrocytes, both autogenous and xenogenic, have been used as the main cell source for auricular cartilage engineering. One hundred million cells are needed to create an adult ear. Auricular and nasal chondrocytes yield more cartilage at a faster rate than articular cartilage. They also have superior histologic and biochemical properties. The continued problems remain of dedifferentiation of cells, limited donor supply, and short time frame for proliferation. The use of chondrogenic stem cells from bone marrow, periosteum, and adipose is being explored. Managing the cell cultures through pathways not fully understood has proven challenging. Inducing factors to stimulate cartilage formation include growth factors and bioreactors. Uncontrolled cell proliferation and potential tumor growth are still concerns.

The use of new “smart” scaffolds of nanocomposite polymers with surface modifications to stimulate and control cell attachment, growth, and differentiation and populated with stem cells may be the way of the future. The problems of skin coverage of the framework and its effect on the ultimate aesthetics will still prove to be challenging.

Clinical application is in its infancy. Four patients underwent reconstruction using a two-stage approach, with cultured chondrocytes injected into the abdominal wall, forming a mature block of cartilage.93 In a second stage, an ear framework was created. No absorption of chondrocytes was observed (Figs. 14 and 15). Composite tissue allotransplantation of an ear has not been reported, but the anatomical and technical aspects of harvesting the auricle as a neurovascular facial subunit have been described.94

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CONCLUSIONS

The future of ear reconstruction rests with tissue engineering and possibly composite tissue allotransplantation. Hearing restoration will be achieved with completely implantable hearing devices or new surgical techniques. When these goals are attained, current approaches described will be rendered obsolete.

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PATIENT CONSENT

Patients provided written consent for the use of their images.

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ACKNOWLEDGMENTS

The authors thank Kathy Bush for administrative assistance and Farzine MacRae for film editing.

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