Ear Reconstruction

Congenital malformations of the external ear are uncommon birth defects with long-term sequelae for children and their families. The impact of such deformities on the patient can be both physical and emotional. 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.

The 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 3 decades.[1] More recent innovations have also included the use of alloplastic frameworks, incorporation of temporoparietal fascial flaps, and osteointegrated implants for the anchoring of prosthetic auricles.

Today, the basic steps in microtia repair require an average of 2-4 stages and involve the use of either an alloplast or the patient's rib cartilage to serve as a framework that is implanted under the skin. Subsequent stages may involve creating a lobule, separating the reconstructed auricle from the head, and constructing a tragus.

Surgeons 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 rigid, biocompatible 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.

Moreover, a study by Otto et al of patients with lobular-type microtia indicated that the affected ear has less than half of the available skin surface area that a healthy ear has. Scanning plaster ear models with a microcomputed tomography scanner or a cone-beam computed tomography (CT) scanner, and then converting the images into mesh models, the investigators determined that healthy, adult-sized ears in the study had a mean total skin area of 47.3 cm2, compared with an average of 14.5 cm2 for ears with microtia.[2]

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.

Frequency

Congenital 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 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 with 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, branchio-otorenal 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.

Rarely 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.

The 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 more 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.

Microtia 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 is usually 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. Grade 1 to Grade 4 microtia are depicted in the images below.

Ear reconstruction is indicated when a child with microtia has reached sufficient age, which may be between 3 and 6 years old. The latter age is typically recommended for rib cartilage reconstruction because sufficient time must be allowed for 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.

A survey conducted by Im et al of members of the American Society of Plastic Surgeons found that in terms of pediatric patients, 49% of respondents who performed microtia reconstruction preferred to operate on patients aged 7-10 years, while 40% preferred operating on children aged 4-6 years.[3]

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 radiographs 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, addressing the hemifacial microsomia first is best, 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 the first 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.

If rib cartilage is to be used, the donor cartilage must be of the appropriate size before reconstruction can be contemplated (see Preoperative details). Adequate cartilage size is generally 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.

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.

Unless indicated by the patient's overall medical condition, no particular laboratory studies are obtained routinely.

Aural atresia repair requires a fine cut noncontrast axial and coronal CT scan of the temporal bones. The timing of this study is not critical and may be deferred until the otologic procedure is anticipated.

For microtia repair, no routine diagnostic procedures are necessary, unless a thorough history and physical examination reveal that particular studies are necessary.

Because microtia consists of malformed cartilages and skin appendages, no routine histologic examination is indicated. In fact, no pathologic specimen is obtained under normal circumstances.

Meurmann staged microtia as follows:

• Grade 1: Malformed auricle of smaller than normal size but retaining characteristic features

• Grade 2: Rudimentary auricle consisting of a low oblong elevation hook formed at the cranial end corresponding to the helix

• Grade 3: A more defective auricle with a malformed lobule and the rest of the pinna being totally absent

Grade 3 is the abnormality most commonly encountered in patients desiring reconstruction. Note that anotia is not considered under the above classification.

Nonsurgical 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 is often 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.

The mainstay of surgical therapy for microtia reconstruction has been costal cartilage rib grafting. This is typically a 3-4 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. A fourth stage may be added later to create a neotragus.

Another option with microtia reconstruction is the use of porous polyethylene (Medpor as seen in the image below) as the framework. Proponents for the use of this alloplastic option cite the ability to start the reconstruction at an earlier age, as young as age 3. This is possible because one does not need to wait for rib cartilage to achieve appropriate size. Another advantage is avoiding the pain and potential deformity of the rib donor site. The reconstruction may be completed in 2 stages, as opposed to 4 with the rib option.

The final cosmetic result may be superior with alloplasts because framework projection is easier to achieve, the need to sculpt is limited, and the alloplast does not resorb. On the other hand, a danger of extrusion or infection exists with alloplast that is only rarely seen with cartilage. The first stage of alloplastic reconstruction generally takes longer to perform but is associated with a shorter hospital stay. Shaving half the head is necessary, in order to make a long transverse incision to lift a temporoparietal flap. This may result in areas of temporary or permanent alopecia.

As with reconstruction using cartilage, a template from the normal ear is used. The auricular framework is constructed from 2 components, which are trimmed to fit the template. The 2 components are welded together using thermal cautery or are sutured together with permanent suture. A temporoparietal flap measuring 12 X 12 cm is harvested through a long horizontal incision 6 cm superior to the future cephalic border of the helical rim. The temporoparietal flap covers the alloplast, and a full-thickness skin graft is placed on the flap. Split-thickness grafts are preferred in heavier and older patients owing to improved rates of take. Small split-thickness grafts may be obtained from the ipsilateral scalp with minimal risk of visible scarring.

The second stage consists of lobule transposition, very similar to the second stage performed with rib cartilage. A third and fourth stage, as needed with the rib cartilage technique, are generally not needed with the alloplast option.

In the authors’ practice, families are presented with both options and are allowed to decide which option they prefer based on their understanding of the risks and benefits. Patients with prior atresia repair are encouraged to pursue the alloplast option.

Timing of reconstruction using rib 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.

A retrospective study by Moon et al suggested that three-dimensional (3-D) CT scanning of the rib cage is an effective means of preoperatively evaluating the size of the eighth costal cartilage prior to its use in microtia-related ear reconstruction. The study, which involved 97 patients, found that costal cartilage lengths assessed with 3-D CT scanning correlated well with those determined intraoperatively.[4]

If the alloplastic option is considered, the patient should be evaluated for a palpable superficial temporal pulse, in order to predict adequate blood supply to the temporoparietal flap. Patients as young as age 3 may be considered for this option, and slight overcorrection of the framework should be carried out in younger patients to allow for future ear growth on the normal side.

Rib Option

See the list below:

• Stage 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 because the root of the helix is usually 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, limiting the amount of dissection is important. 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, although 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 or "bikini line" area. Split-thickness grafts are used in patients heavier than about 50-60 kg. The graft 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 are also 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).[5] 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.

Alloplast Option

See the list below:

• Stage 1 reconstruction: Placement and covering of the framework

  • Once a template from the normal ear has been made and the appropriate location determined for ear placement on the malformed side, the ipsilateral side of the head is shaved up to the vertex of the scalp. The superficial temporal artery is palpated or Dopplered. The side of the head and face and the skin graft donor area are then prepared and draped. The skin graft should measure 4 cm by 12 cm, and the donor site is closed primarily with a subcuticular closure.

  • A 12 cm horizontal incision is made on the scalp, 6-8 cm superior to the remnant. The incision should not extend through the underlying fascia. The skin is lifted off the fascia, preserving hair follicles and identifying viable arterial and venous branches. A second incision is made in a curvilinear fashion at, or slightly peripheral to, the hairline, taking care not to jeopardize the underlying fascia. The superficial temporal artery should be ligated and divided at its frontal branch, taking care not to injure the temporal nerve.

  • The goal is to lift a temporoparietal flap measuring 12 x 12 cm. Once the incisions in the fascia have been made, the flap is then elevated in a superior to inferior manner and passed through the inferior, curvilinear incision. Care is taken not to injure the superficial temporal, occipital, or postauricular vessels as they enter the flap. The flap is then irrigated with saline.

  • The alloplastic framework is then assembled, using the template as a guide. Excess plastic material is trimmed off, and the 2 components are fixed together using a thermal cautery or 4-0 clear nylon suture. A small notch is cut in the medial side of the framework to allow a drain to pass through without pushing the framework off the side of the head. The framework is then soaked in dilute Betadine solution.

  • The curvilinear incision at the hairline has essentially described an antero-inferiorly based flap. This flap should now be elevated in the subcuticular plane, making a pocket into which the framework will fit. One must not "button hole" the skin. Dissection is carried out beyond the remnant cartilage and lobule. The cartilage is dissected out and discarded.

  • The framework is now placed into the pocket. A small suction drain is placed inferiorly through the skin and passed deep to the framework through the notch made for that purpose. The temporoparietal flap is draped over the framework, and the drain is placed on suction. One should note the presence of air leaks, and repair them with 4-0 chromic sutures. The drain is then secured on the skin. Note that neither the framework nor the flap is sutured in place.

  • The skin graft is then trimmed and inset in the usual fashion with 4-0 chromic suture. A second suction drain is placed under the skin and runs from a point just superior to the framework up to the vertex of the head. Whereas the first drain functions to conform the temporoparietal flap to the framework, the second acts to conform the skin graft to the temporoparietal flap, as well as to prevent the accumulation of fluid under the scalp. The scalp incision closure must therefore be airtight. A subcuticular closure is used. No bolster is placed on the skin graft, but a cup type dressing (Glasscock) with a Velcro strap is used to protect the operative site.

• Stage 2 reconstruction: Creation of the lobule

  • As soon as 4 months following stage 1 of the repair, the patient may be ready for stage 2. As with the rib cartilage option, the second stage involves transposition of the lobule using a Z-plasty technique.

  • The inferior pole of the framework is delivered, taking care not to expose the plastic. The lobule is filleted open, allowing the lobule to be wrapped around the framework. A 2-0 nylon suture is usually not needed to approximate the posterior skin of the lobule to the deep surface of the inferior pole of the cartilage framework because the postauricular sulcus has already been formed at stage 1.

Rib Option

See the list below:

• Stage 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 48-72 hours, primarily for pain control.

  • 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 is usually 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. Most importantly, the suture lines must 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: Because 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.

Alloplast Option

See the list below:

• Stage 1: The patient is admitted for 24-72 hours, depending on how comfortable the parents are with drain care. Drains are removed 3-7 days after surgery. The drains are somewhat larger (3-4 mm diameter) for the alloplast option. The cup dressing stays in place day and night for 2 weeks and then is worn at night for an additional 2 weeks.

• Stage 2: Again, this is probably the stage associated with the least postoperative morbidity. Most importantly, the suture lines must be kept clean and covered with antibiotic ointment for approximately one week.

• 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.

Patients are seen preoperatively, at 1 week postoperatively, and as needed thereafter.

A literature review by Long et al found the average overall rate of complications in microtia-related ear reconstruction with autogenous cartilage to be 16.2%. The review, which included 60 studies (9415 patients total), also found that the use of two- or multiple-stage techniques with or without preexpansion of tissue did not significantly impact the complication rate, nor did the use of simultaneous midear reconstruction.[6]

Rib option

The most frightening common complication with the rib cartilage 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 is usually 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 because 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.

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. Because 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 because the graft has been secured within a precise confined pocket of skin.

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.

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 week-long course of oral antibiotics may be necessary. Occasionally, a retained suture needs to be removed.

Alloplast option

Exposure and infection of the framework are more worrisome complications for reconstructions using an alloplast than those using rib cartilage. Plastic implants may develop colonization with bacterial biofilms upon exposure, and the ensuing infections may be difficult, if not impossible, to treat without explantation of the framework. Fractures and exposures have been reported to occur as often as 44%.[7] Smaller (< 1 cm) exposures may be successfully closed with local transposition flaps after a 1-mm rim of skin is débrided from the defect. Advancement and rotation flaps are not as successful.

If the framework becomes grossly infected, the implant is removed. Reconstruction using rib cartilage can be attempted later, giving the soft tissues time to regain some pliability and a healthy blood supply. Reconstruction using another Medpor implant may also be considered, but it is recommended that a 60-mL tissue expander be inserted through the previously existing scalp scar once healing has occurred. After several weeks of expansion, the expander is removed and the new alloplast is inserted.

Under ideal conditions, a surgeon with some degree of artistic ability who uses sound judgment can expect a good result after 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.

A study by Park and Park indicated that in microtia patients with constricted ear features, reconstructive surgery that completely replaces remnant cartilage with costal cartilage and maximally saves remnant skin produces better aesthetic results than procedures that preserve remnant cartilage. Using a four-point Likert scale to measure aesthetic outcomes, the investigators found the average score for cartilage-replacement surgery to be 3.36 (between good and excellent), compared with 2.56 for cartilage-preservation procedures (between fair and good).[8]

Surgeons are constantly attempting to improve results with microtia repair.

Chin et al have described modifications to the rib cartilage framework to[9] augment the definition. They describe a Y-shaped piece of cartilage to augment the superior and inferior crus of the antihelix, as well as blocks of cartilage to reconstruct the tragus during stage 1.

Jiang et al[10] have describe a 2-stage technique using rib cartilage, which makes use of a retroauricular fascial flap to cover the rib graft posteriorly during stage 1. Conchal excavation and tragal reconstruction are accomplished in stage 2.

Chen et al[11] have made use of a second stage in which an ultrathin split-thickness skin graft is left attached to the helix to cover the raw surface created by elevating the framework. This results in fewer visible suture lines. A temporoparietal flap is raised during this stage to cover a cartilage block that adds projection to the auricle.

Readers are referred to these references for more details.

The greatest morbidity with the rib cartilage technique is at the harvest site. The postoperative pain, the thoracic scar, and the occasional concavity produced in the chest area have motivated surgeons to seek an adequate alternative. The use of porous alloplastic material has proven to be effective, but concerns persist about its long-term viability and the propensity for exposure and infection.

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 should probably 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.

Seeding autologous cartilage onto a biologic framework to grow tissue in a foreign host is now possible. 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.