You are in: eMedicine Specialties > Otolaryngology and Facial Plastic Surgery > RECONSTRUCTIVE SURGERY Ear ReconstructionArticle Last Updated: Jun 14, 2006AUTHOR AND EDITOR INFORMATIONSection 1 of 11
  Author: Michael J Biavati, MD, Clinical Assistant Professor, Department of Otolaryngology, University of Texas Southwestern Michael J Biavati is a member of the following medical societies: American Academy of Otolaryngology-Head and Neck Surgery, American Academy of Pediatrics, American Cleft Palate/Craniofacial Association, American College of Surgeons, American Laryngological Rhinological and Otological Society, American Society of Pediatric Otolaryngology, Society for Ear, Nose and Throat Advances in Children, and Texas Medical Association Coauthor(s): Joseph L Leach, Jr, MD, Associate Professor of Otololaryngology, University of Texas Southwestern Medical School Editors: John C Li, MD, Private Practice in Otology and Neurotology; Medical Director, Balance Center; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Dominique Dorion, MD, MSc, FRCSC, Program Director and Division Chair, Professor of Surgery, Division of Otolaryngology, University of Sherbrooke, Canada; Christopher L Slack, MD, Otolaryngology-Facial Plastic Surgery, Private Practice, Associated Coastal ENT; Medical Director, Treasure Coast Sleep Disorders; Arlen D Meyers, MD, MBA, Professor, Department of Otolaryngology-Head and Neck Surgery, University of Colorado School of Medicine Author and Editor Disclosure Synonyms and related keywords: ear reconstruction, microtia, anotia, external ear deformity, aural atresia, external ear reconstruction, microtia repair, auricular reconstruction, INTRODUCTIONSection 2 of 11
  Congenital malformations of the external ear are uncommon birth defects with long-term sequelae for children and their families. The impact of such deformities can be both physical and emotional for the patient. Parents often experience feelings of guilt because they believe they have caused the deformity. School-aged children may be the object of teasing and ridicule. Hearing loss due to associated ear canal atresia can result in learning difficulties. Auricular malformations range from anotia to mild alterations in the external form of the ear. Fortunately, knowledge of reconstructive techniques and audiological rehabilitation continues to improve and benefit patients. History of the ProcedureThe earliest reports of auricular reconstruction date back to 600 BC from passages in the Sushruta Samhita, in which the great Indian surgeon Sushruta describes ear lobe reconstruction using local skin flaps. In the 16th century, Gaspare Tagliocozzi reported using a transfer flap from the arm to reconstruct the ear. In 1845, Dieffenbach made the next major report when he described the reconstruction of the upper part of an auricle that had been severed sharply by a sabre. Surgeons of the 19th century believed total auricular reconstruction was impossible because no source of skin or elastic cartilage was acceptable to create the auricle. The modern age of auricular reconstruction begins in the 20th century. In 1920, Gillies first described the use of costal cartilage grafts in reconstructing the auricle. In 1930, Pierce described the principle of creating an auricular framework from cartilage grafts. Tanzer further popularized the use of autogenous rib cartilage for reconstruction. Many of the techniques he described are the foundation of microtia repair today. Brent has further refined these techniques over the last 2 decades. More recent innovations have also included the use of a silastic framework, incorporation of temporalis fascial flaps, and osteointegrated implants for the anchoring of prosthetic auricles. Today, the basic steps in microtia repair require an average of 3-4 stages and involve the use of the patient's rib cartilage to carve a framework that is implanted under the skin. Subsequent stages involve creating a lobule, separating the reconstructed auricle from the head, and constructing a tragus. ProblemSurgeons involved in microtia repair have long recognized the difficulty of creating a natural appearing ear. These problems are 2-fold and include the creation of a cartilaginous framework and its coverage with skin. No natural substitute exists for the thin pliable auricular cartilage. Nor is skin available of similar quality and elasticity to that covering the auricle. One key to successful reconstruction is to provide sufficient relief in the helix, scaphoid fossa, and antihelix to create the illusion of thin skin overlying thin cartilage. Problems such as thick skin, hair-bearing skin, and poor quality cartilage serve to frustrate the surgeon's attempt to achieve the desired result. Other challenges in the creation of the auricle are properly positioning the reconstructed ear in relation to the opposite ear, providing sufficient projection of the auricle from the head, creating a postauricular sulcus, and reconstructing a natural appearing lobule and tragus. FrequencyCongenital microtia occurs with a frequency of 1 per 7000 live births. The incidence of microtia varies by race, with the highest incidence in persons of Asian, Mexican, and Latin American descent, as well as certain Native American groups. Persons of European origin have a lower incidence, while people of African descent have the lowest incidence. Males are 3 times more commonly affected than females, and the right ear is more commonly involved by a 2:1 ratio. Bilateral defects occur in only 12% of nonsyndromic cases, as compared to 50% of syndromic cases. In two thirds of cases, the microtia occurs as an isolated defect. Nearly 28% of microtic ears occur in association with other birth defects. Ten percent of microtia occurs as part of a well-defined syndrome. A large proportion of microtia is believed to be due to autosomal inheritance with variable expression and incomplete penetrance. Coexisting conditions that may be present include Goldenhar syndrome, branchiootorenal syndrome, branchial cleft cysts, holoprosencephaly, Treacher Collins syndrome, and Robinow syndrome. Other malformations may include mandibular deformities, facial paralysis, and maldevelopment of the facial and cranial bones. EtiologyRarely can an environmental or genetic cause for microtia be found. Isotretinoin and thalidomide are teratogens that can cause microtia. Microtia also can occur as a result of fetal alcohol syndrome or maternal diabetes embryopathy. Single gene disorders such as Treacher Collins syndrome or chromosomal abnormalities such as trisomy 18 also can result in microtia or anotia. PathophysiologyThe development of the auricle involves many embryonic stages. Any small change in any of these stages may result in various forms of deformity. Some of these deformities are known variously as lop ear, cup ear (constricted ear), or cryptotia. These entities differ from microtia and are not discussed. A relationship between the severity of malformations and the amount of the auricular deformity has been noted. In general, the greater the amount of auricular tissue present, the less severe the associated malformations. The precise pathophysiologic mechanisms by which teratogenic or genetic influences result in microtia have yet to be defined. ClinicalMicrotia is a congenital disorder and is immediately recognizable at birth. The malformed ear may be completely absent (grade 4 microtia or anotia), but, most commonly, a residual malpositioned lobule is present beneath a rudimentary hillock of cartilage (grade 3 microtia). Microtia usually is associated with aural atresia in the higher stages. Grade 1 microtia (a small ear with normal architecture) often has an associated patent ear canal. Grade 2 microtia (a small ear missing much of the architectural features of a pinna) may or may not have a patent canal or tympanic membrane. INDICATIONSSection 3 of 11
Ear reconstruction is indicated when a child with microtia has reached sufficient age, which is usually age 6 years. This allows the normal ear to reach most of its adult size and act as an accurate template for the ear to be reconstructed. In addition, the costal cartilage will achieve sufficient size to provide adequate donor material for the framework. RELEVANT ANATOMYSection 4 of 11
Placing the reconstructed ear in the proper location is important. This placement is best determined by taking measurements from facial landmarks (ie, lateral canthus, alar facial crease, lateral commissure) to the normal ear and transposing the same measurements to the side of the deformity. Making a template of the normal ear from overexposed x-ray film ensures that the reconstructed ear has the appropriate size and shape. In many children, the hairline on the abnormal side is unusually low, causing the cartilage framework implant to be placed at least partially under hair-bearing scalp. Recognizing this problem at the outset is better than attempting to shift the framework inferiorly and anteriorly. The problem of hair over the ear can be addressed later using electrolysis, skin grafting, or laser hair removal. In patients with hemifacial microsomia, measurements from the normal side of the face would cause the surgeon to place the auricular framework far posterior to the auricular remnant. This eventuality would prevent the surgeon from using the malformed hillocks in lobule reconstruction. In these cases, it is best to address the hemifacial microsomia first, so that mandibular symmetry may be achieved. With this accomplished, proper positioning of the auricle is more likely to result. Typically, the otologist performs hearing restoration surgery after 3 or 4 stages of microtia repair are complete. The temporomandibular joint, the path of the facial nerve, and the location of the temporal fossa dura are landmarks that dictate the position of the new ear canal. Occasionally, in persons with microtia and aural atresia, the pinna is not centered over the ideal location for canal placement. In these individuals, the auricular framework can be shifted a few millimeters in the appropriate direction or the conchal bowl may be enlarged. By the time auricular reconstruction is initiated, ossification of the mastoid bone is complete and the facial nerve, deep to the planes critical to microtia repair, should be protected. Nevertheless, overzealous use of the electrocautery may transmit damaging current to the nerve, particularly in smaller children. In patients with multiple facial anomalies in whom the course of the facial nerve is in question, nerve monitoring should be considered. Skin quality is another anatomic factor critical to a good outcome. Dissection of the pocket for the auricular framework must be carried out in the subcutaneous plane, deep to the subdermal vascular plexus, but superficial to the galea and other elements of the superficial musculoaponeurotic system complex (SMAS) plane. This allows the skin to be stretched and conformed to the underlying framework. Any prior damage to the skin in this area makes the task of reconstruction significantly more difficult. Radiation therapy, actinic damage, cigarette smoking, and trauma have the potential to rob the skin of critical blood supply, deprive it of healing characteristics, and prevent it from adequately revealing the intricacies of the cartilage framework. The donor rib cartilage must be of the appropriate size before reconstruction can be contemplated (see Preoperative details). Adequate rib cartilage size generally is achieved by the time the child is aged 6 years. This is when the surgeon may harvest the cartilaginous portions of the contralateral sixth, seventh, and eighth ribs to form the framework. To ensure that the cartilage remains viable and has the potential for future growth, perichondrium must be preserved over the harvested portions. In taking pains to preserve the deep perichondrium, the surgeon often violates the parietal pleura. This problem is addressed during surgery by evacuating any air from the pleural cavity with a Valsalva breath, sealing the opening with a running watertight closure, and placing a temporary suction drain in the chest. CONTRAINDICATIONSSection 5 of 11
Auricular reconstruction using costal cartilage probably is not indicated for patients with limiting anomalies in other parts of the body. Other contraindications include lack of graft material in patients with previous cartilage harvest, patients with poor skin quality in the auricular area secondary to burns or previous surgery, and patients who are poor anesthetic risks. WORKUPSection 6 of 11
Lab Studies
Imaging Studies
Diagnostic Procedures
Histologic FindingsSince microtia consists of malformed cartilages and skin appendages, no routine histologic examination is indicated. In fact, no pathologic specimen is obtained under normal circumstances. StagingMeurmann staged microtia as follows:
Grade 3 is the abnormality most commonly encountered in patients desiring reconstruction. Note that anotia is not considered under the above classification. TREATMENTSection 7 of 11
Medical therapyNonsurgical treatment of microtia is primarily with prosthetic replacement. This method of treatment has the advantage of providing an ear with a very natural appearance and should be offered to the patient or their parents as an alternative to surgical reconstruction. Prosthetic replacement may be the best alternative in a person with complete anotia because reconstruction of the lobule is a challenging task and often is met with less than optimal results. Disadvantages of prosthetic reconstruction include the fact that it must be attached to the side of the head. Adhesives may be used, but these have limited strength. Osseointegrated implants to the temporal bone may be joined to a metal framework, which is then connected to the prosthesis by means of magnets. This is a somewhat more secure option than adhesives but is not without problems. The prosthesis is expensive and also wears out, needing frequent replacement. The prosthetic has a tendency to fade when exposed to sunlight or seawater. Obviously, a prosthetic is insensate and feels like an unnatural appendage or ornament rather than part of a patient's own body. The potential also exists for social embarrassment if the prosthesis becomes unglued or detached in public. Surgical therapyThe mainstay of surgical therapy for microtia reconstruction is costal cartilage rib grafting. This is typically a 3-stage procedure, whereby the ear is created from local tissue flaps and a cartilage framework carved from rib cartilage. The first stage involves the carving of rib cartilage into the shape of an external ear and placing the graft into a pocket created in the skin overlying the temporal bone. In the second stage, a Z-plasty is performed, which rotates the auricular remnant inferiorly, creating a lobule. The third stage elevates the cartilage graft off the temporal bone, creating a postauricular sulcus with a split-thickness skin graft. These 3 stages are spaced at 6-month intervals to allow for reestablishment of blood supply between procedures. Preoperative detailsTiming of surgery is based on 2 primary factors. First, a sufficient amount of costal cartilage must exist, specifically the synchondrosis of the fifth through seventh ribs. Second, in unilateral microtia repairs, the normal ear must be at least 85% of normal adult size. Typically, sufficient size is achieved in most children by the time they are aged 5-6 years. Intraoperative detailsStage 1 reconstruction: Construction of the cartilaginous framework In forming the helix of the auricular cartilage, the cartilage of the eighth rib is sutured to the carved portion of the sixth and seventh ribs. For attachment of the eighth rib cartilage, 4-0 clear nylon is used. The root of the helix no longer is extended into the conchal bowl, since the root of the helix usually is resected during the creation of the external meatus. Repositioning of the helical graft allows more of the eighth rib to be used for the posterior inferior helix, achieving improved helical relief. In dissecting a skin pocket to receive the rib cartilage graft, it is important to limit the amount of dissection. Undermining of skin should be carried out only 3-4 cm peripheral to the proposed location of the new ear. Overaggressive undermining may result in compromise of the blood supply or promote formation of a hematoma. Too large of a pocket also results in blunting of the angle between the helical rim and the side of the head, resulting in less than desired relief. The incision is made near the anterior edge of the malformed auricular cartilage remnant. A small amount of cartilage is left anterior to the incision to act as a tragus during stage 4 reconstruction. After making the incision, the natural tendency is for dissection to proceed in the sub–SMAS plane or in the thin plane that exists between the temporoparietal fascia and the temporalis fascia. However, the appropriate plane of dissection for auricular reconstruction is the plane between the temporoparietal fascia and the subdermal plexus. When in the proper surgical plane, the surgeon should be able to observe a thin layer of fat adhering to the deep layer of the dermis. This fatty layer should be removed with careful sharp dissection. Peripherally and superiorly, hair follicles are visualized and clipped at this time. Dissection into the deep layer of the dermis compromises blood supply and reduces the pliability of the skin. Skin pliability may be improved by intraoperative tissue expansion or by mechanical stretching of the skin. Bleeding from the subdermal plexus is controlled with bipolar cautery. Avoiding the use of epinephrine in the skin flap is important to monitor blanching. Should blanching occur at the time of skin closure, sutures are removed, further dissection is performed, and intraoperative tissue expansion is repeated with moist gauze sponges. A wedge of extra cartilage is banked deep to the scalp superiorly. This will be used as a pedicled buttress during stage 3 to aid in auricular projection. Once the rib cartilage graft has been inserted into the pocket, the incision is closed over 2 small suction drains. A 5-0 mild chromic suture for skin closure is used, avoiding the need for suture removal in less-than-cooperative children. Stage 2 reconstruction: Creation of the lobule Typically, 6 months following stage 1 of the repair, the patient is ready for stage 2. The second stage involves transposition of the lobule using a Z-plasty technique. With the classic grade 3 microtia deformity, the patient usually has a well developed, though improperly positioned, lobule. Superior to this lobule is a variable amount of malformed cartilage, typically covered by a roll of redundant skin. At the time of lobule transposition, this roll of redundant skin is left attached to the lobule. This skin roll may be incorporated into the inferior helix. The result is a smoother, more natural transition from lobule to helix. The inferior pole of the cartilage framework is delivered, and the lobule is filleted open, allowing the lobule to be wrapped around the cartilage. This avoids the problem of the lobule acquiring a "pasted on" appearance. A 2-0 nylon suture is used to approximate the posterior skin of the lobule to the deep surface of the inferior pole of the cartilage framework, thus accentuating the inferior portion of the postauricular sulcus. Stage 3 reconstruction: Creation of the postauricular sulcus During this stage, an incision is made from the root of the helix anteriorly, along the top of the ear, and posteriorly into the junction of the lobule with the postauricular skin. This creates a near total circumferential incision of the skin covering the lateral surface of the cartilaginous framework. Care must be taken when creating this incision to ensure that adequate blood supply remains to the auricular skin. Typically, if a sufficient period of time has passed since the initial placement of the cartilaginous graft (typically, a minimum of 1 y), the skin then receives most of its blood supply from the underlying cartilage and its perichondrium. If at any point the blood supply appears to be compromised, the incision is not extended as far anteriorly. The cartilaginous graft is then elevated off the mastoid periosteum. Typically, elevation is performed to a point where the auricle is hinged anteriorly by its attachment to the preauricular skin. A sulcus is thereby created to accept a split-thickness skin graft. Projection of the auricle is accentuated by using the previously banked cartilage from stage 1. This cartilage is left attached to the SMAS layer and raised as an inferiorly based flap. The cartilage is wedged into the depths of the new postauricular sulcus, and secured with 4-0 Vicryl suture. A full-thickness skin graft is then harvested, typically from the groin area. This is used to cover the remaining mastoid periosteum and posterior portion of the auricular cartilage. The graft is pie-crusted and sewn in place using a running 4-0 chromic suture. Several quilting sutures also are placed through the graft to help adhere the graft to the underlying tissues. A tie-down bolster is then placed over the graft and is left in place for 6-7 days. Stage 4 reconstruction: Creation of a tragus If sufficient tissues remain from the auricular remnant, these can be used to create a tragus. Typically, a tragus needs to be created de novo. This is easily accomplished by using a composite graft from the opposite ear. A skin-cartilage graft is harvested from the antihelix and conchal bowl of the normal ear. A J-shaped incision as described by Aguilar is made anterior to the location of the external auditory meatus (assuming the patient is a candidate for external auditory canal [EAC] reconstruction). The cartilage is then placed into this incision, and the skin portion of the graft is sutured anteriorly. A horizontal mattress suture is then placed through the preauricular skin and into the cartilage graft, pulling it forward and creating the tragal eminence. Often, minor refinements to this technique are necessary. When EAC reconstruction is undertaken, the auricle may require some repositioning. Postoperative detailsStage 1 The 2 small butterfly drains placed intraoperatively superiorly and inferiorly in the skin pocket are attached to vacuum blood collection tubes, which are changed every 2-4 hours. After 1-2 days, the drains are removed when output becomes straw colored and when less than 2-3 cc per 8-hour period is collected. A larger suction drain is placed in the chest. The chest incision is covered with surgical tape. Children remain in the hospital for 24-48 hours, primarily for pain control. Patients may be sent home with the drains in place, if necessary. Postoperative pain is related primarily to the rib donor site, and this is reduced by a more limited dissection in this area. A bulky noncompressive mastoid-type dressing is placed over the reconstructed ear and usually is not changed until postoperative day 2. The suture lines are covered with antibiotic ointment twice daily for a week. Absorbable, minimally reactive sutures are placed in small children, obviating the need for suture removal. Patients may wet the suture lines beginning on postoperative day 2. A protective cup ear dressing with a Velcro strap may be used for more active children until healing is complete. This is particularly useful to prevent harming the reconstructed ear at night while sleeping. After all surgical procedures, patients are advised to limit strenuous activity for approximately 2 weeks. Stage 2 This is probably the stage associated with the least postoperative morbidity. It is most important that the suture lines be kept clean and covered with antibiotic ointment for approximately one week. Stage 3 Routine suture care is indicated after this stage as well. Stage 4 Since a composite graft is obtained from the normal ear, both ears cause some discomfort postoperatively; the patient may need to use protective occlusive dressings temporarily. Routine suture line care is indicated here as well. Managing unwanted hair Although many hair follicles typically are clipped and removed during stages 1 and 3, persistent hair growth around the upper scapha and helix continues to be a problem in some patients. Some patients simply clip the hairs short. Electrolysis is not well tolerated in the pediatric age group. Laser hair removal using light directed at the hair pigments has been successful; nevertheless, more than one treatment is generally required. Follow-upPatients are seen preoperatively, at 1 week postoperatively, and as needed thereafter. Scheduling surgical stages at least 6 months apart is best. COMPLICATIONSSection 8 of 11
The most frightening common complication with microtia repair is skin loss. For this reason, the surgeon is doubly careful to avoid damaging the subdermal plexus or stretching the skin unduly. The field is never injected with epinephrine-containing solutions so that blanching of the skin may be monitored accurately. Fortunately, when skin loss occurs, it usually is limited in scope and can be managed adequately with the excision of small portions of exposed cartilage and aggressive wound care. These areas usually heal by secondary intent. Occasionally, portions of the skin graft are lost. If the underlying perichondrium is still intact, a new graft may be placed successfully. For larger areas of skin loss, a local flap procedure needs to be performed. The temporoparietal flap is a good choice, since it is thin, pliable, and in close proximity. After turning down the flap and covering the exposed cartilage, the flap is grafted onto skin. Although the grafted skin has a poor match of color, texture, and thickness, these differences tend to minimize with time. Resorption of the cartilage graft may occur if the cartilage is denuded of perichondrium during the harvesting stage or during the formation of the framework. Keloid and hypertrophic scar formation are problematic because they defy any satisfactory correction and are difficult to predict. Although surgical resection of the scarred tissue may be attempted, the results are likely to be disappointing. Local injection of long-acting steroid compounds may be attempted. Dislocation of the cartilage elements of the framework may occur, especially if the helix is not secured adequately onto the cartilage base. For this reason, multiple permanent sutures are used. Since wire has a tendency to extrude or become infected, it no longer is used. Despite the possibility of suture failure, the potential for cartilage dislocation is small since the graft has been secured within a precise confined pocket of skin. Infection may occur despite meticulous sterile technique and perioperative antibiotic therapy. Most infections are small and well localized. In some cases, local wound care and a weeklong course of oral antibiotics may be necessary. Occasionally, a retained suture needs to be removed. OUTCOME AND PROGNOSISSection 9 of 11
Under ideal conditions, a surgeon with some degree of artistic ability who uses sound judgment can expect a good result after 3-4 adequately spaced stages. Nevertheless, much of the prognosis depends on factors beyond the surgeon's immediate control, such as skin pliability, scar tissue formation, and the resolution of edema. FUTURE AND CONTROVERSIESSection 10 of 11
The greatest morbidity with this procedure is the use of autologous rib cartilage for the reconstruction. The postoperative pain, the thoracic scar, and the occasional concavity produced in the chest area have motivated surgeons to seek an adequate alternative. As mentioned above, prosthetic ears, with or without osteointegrated fixation, are popular with some physicians. Although these prosthetics are remarkably natural in appearance, they have several drawbacks. These include limited longevity, lack of sensation, and unnatural feel. Prosthetics probably should not be considered a first-line remedy for microtia. Cadaveric (homograft) or animal (xenograft) cartilage has been demonstrated to have high resorption rates that make them unacceptable for preserving the delicate architecture of the reconstructed ear. In addition, concern exists about the transmission of HIV or slow viral diseases. Artificial materials (allografts) have demonstrated more promise. However, time will tell if these implants remain stable over the long term and resist infection, extrusion, or rejection. Within the past few years, it has become possible to seed autologous cartilage onto a biologic framework to grow tissue in a foreign host. An auricular cartilage framework was grown in a nude mouse, whose picture was circulated widely by the lay press. Nevertheless, problems remain with such technologies, primarily because the new cartilage lacks the skeletal strength to withstand the contracting forces of the skin pocket and the subsequent scar formation. Currently, the autologous rib cartilage graft remains the criterion standard for auricular reconstruction. REFERENCESSection 11 of 11
Article Last Updated: Jun 14, 2006 |
