Embryology

The inner ear begins as the otic placode at approximately the third week of gestation, and it then forms into the otic pit and otic cyst. The external ear begins to form in the fifth week of gestation. The auricle begins as six small buds of mesenchyme, classically known as the hillocks of His, surrounding the dorsal end of the first branchial cleft.^7–10 On either side of the first branchial cleft are the first (mandibular) and second (hyoid) branchial arches. Hillocks 1 through 3 arise from the first branchial arch, and hillocks 4 through 6 arise from the second branchial arch. Conventional teaching holds that the first hillock forms the tragus, the second and third form the helix, the fourth and fifth form the antihelix, and the sixth forms the antitragus. The majority of the central ear is derived from hillocks 4 and 5, and the lobule appears to be one of the last parts of the ear to develop (Fig. 192-1). It has been estimated that the hyoid arch forms about 85% of the auricle.⁵ The exact embryology of each of these hillocks remains unclear. The position of the auricular complex begins at the anterior neck region. As the mandible develops during gestational weeks 8 through 12, the auricular complex moves in dorsal and cephalic directions. The etiology of microtia remains unknown in most cases, although the inciting event that arrests development of the ear must occur during the first trimester, and may be related to abnormal neural crest cell migration.

Figure 192-1. Embryonic development. The ear develops from six hillocks of His. Hillocks 1 through 3 are from the first branchial arch, and hillocks 4 to 6 are from the second branchial arch. Hillock 1 forms the tragus, hillock 2 forms the root of the helix, and hillock 6 forms the antitragus. Hillocks 2 through 5 appear to form the helix and antihelix.

Known teratogens, such as the retinoic acid derivative isotretinoin (Accutane; Roche, Nutley, New Jersey), can produce forms of microtia in conjunction with craniofacial, cardiac, thymic, and CNS anomalies, a condition commonly known as retinoic embryopathy.¹¹ Thalidomide and mycophenolate mofetil also have been reported to be associated with microtia.^12,13 Microtia is associated with other anomalies about 50% of the time. Microtia is most commonly associated with other regional anomalies related to the first and second branchial arches, i.e., facioauriculovertebral syndrome. Within the facioauriculovertebral spectrum are malformations and syndromes that affect the first and second branchial arch derivatives, such as Goldenhar’s syndrome (preauricular nodes, epibulbar dermoids, mandibular hypoplasia), hemifacial microsomia,¹⁴ and oculoauricular vertebral dysplasia (microtia, cervical spine anomalies, and epibulbar dermoids).^15,16 It may be that Goldenhar’s syndrome, hemifacial microsomia, oculoauriculovertebral dysplasia, and microtia are simply variants of the same entity.⁴ Microtia also may be seen in syndromes such as Treacher Collins syndrome, which has an autosomal dominant inheritance pattern.

Ear Anatomy

The anatomic contour of the normal ear must first be reviewed in order to understand the nature and extent of microtic ear deformities (Fig. 192-2). The auricle is an aesthetic sculpture of complex convexities, concavities, and curved lines such as the helix and the antihelix, which are smooth and uninterrupted. The elastic cartilage framework of the auricle is usually pliable yet structurally strong and extraordinarily resistant to trauma. The skin of the ear is fibrofatty and loose over the lobule and the margin of the helix but thin and fixed over the remaining cartilage framework.

Figure 192-2. Normal anatomic landmarks of the ear.

Normal adult ear height ranges from 5.5 to 6.5 cm, which is typically attained by 13 years of age in boys and 12 years of age in girls. The ear goes through rapid growth between 2 and 3 years of age and reaches 95% of its adult size by about age 5. Thereafter it grows at a modest rate until it reaches its adult size during early teenage years. The horizontal width of the ear is achieved at a much earlier age. Protrusion of the ear from the surface of the mastoid should be 1.5 to 2.0 cm, thereby creating an angle between 15 and 20 degrees.¹⁷ The superior margin of the helix is at the level of the tail of the eyebrow in 85% of people. Because the tail of the eyebrow is also quite variable, the level of the upper eyelid also may be used as a landmark if the patient has bilateral microtia.¹⁸ The ear inclination is the angle formed by the vertical axis of the face and the longitudinal axis of the ear with the patient in the Frankfort horizontal position. This is approximately 24.8 degrees, with a standard deviation of 6.2 degrees.¹⁹ Therefore, the longitudinal axis of the ear is not quite parallel with the dorsum of the nose (as is commonly thought), because the ear is in a slightly more vertical orientation.

Microtia

Microtia deformities come in various shapes and sizes, and unfortunately, there is currently no universal, precise, and accurate classification scheme that is clinically useful. Classification schemes are further complicated if the status of the external auditory canal (EAC) and middle ear contents and the presence or absence of an associated syndrome are included.^5,20 Classification usually is simplified by evaluating the external auricular deformities alone. Perhaps dysplasia is a better term than microtia to use in describing ear deformities. Dysplasia deformities typically are divided into three broad and simple categories that have a great deal of overlap.²¹ Type I (Fig. 192-3) is used to designate ears with mild deformity. All major structures are present to some degree, and reconstruction does not require additional tissue. Type II (atypical microtia) dysplasia (Fig. 192-4A to C) includes ears that have all major structures present to some degree. There is a deficiency of tissue, and surgical correction requires the addition of cartilage and skin. Mini-ear and severe cup-ear deformities are included in this category. The external auditory meatus is present, but it may demonstrate some degree of stenosis. Type III (classic microtia) dysplasia (Fig. 192-5A to C) deformities have few or no recognizable landmarks of the auricle, although the lobule usually is present and positioned anteriorly (see Fig. 192-16). Anotia is the complete absence of auricle and lobule. Reconstructive surgeons may find it more useful to simply note the status of the helix and antihelix, the conchal bowl, the lobule, the tragus, and the EAC, because these landmarks dictate the stages of ear reconstruction and the degree of surgical difficulty.

Figure 192-3. Type I microtia. A constricted ear with minimal tissue deficiency.

Figure 192-4. Type II microtia. A, A patient with type II microtia demonstrating a slight deformity with a small helix and missing antihelix. This patient also demonstrated canal stenosis. B, More extensive loss of the helix and antihelix, with a relatively normal canal and conchal cavum. C, A patient with loss of the superior crus of the antihelix and a constricted helix.

Figure 192-5. Type III microtia. A and B, Ears with moderate deformity and a few remaining visible landmarks of the helix. C, No recognizable landmarks of the auricle or canal are apparent, but the lobule is preserved.

Evaluation

Children with microtia typically present to an otolaryngologist early during infancy because of the visible anomaly and parental concerns related to the child’s hearing. The parents are usually concerned with the short- and long-term effects of monaural hearing on the child’s speech development and the possibility of learning disabilities. Physical examination should focus on the mandibular shape and excursion, mouth, maxilla, eyes, and neck to rule out mandibular asymmetry, maxillary asymmetry, epibulbar dermoids, coloboma, and vertebral anomalies, which may indicate that the microtia is part of a syndrome.

Although patients with microtia typically have normal hearing in the contralateral ear, all patients with unilateral microtia should have age-appropriate hearing assessment. Hearing should continue to be monitored and eustachian tube dysfunction in the patent ear should be treated. Radiologic evaluation should include high-resolution computed tomography (CT) scan of the temporal bones to assess degree of atresia; cervical spine films to rule out vertebral anomalies; renal ultrasound to rule out congenital renal malformations; and panoramic (Panorex) films to assess the status of the mandible. If multiple anomalies are found, the child is referred to a multidisciplinary craniofacial team for more comprehensive evaluation.

Planning

Early evaluation by an otologist who is familiar with aural atresia is generally recommended. In most cases of unilateral microtia with aural atresia and a contralateral normal-hearing ear, canal reconstruction is controversial because speech development is expected to be normal. However, children with unilateral hearing loss predictably will have difficulties with sound localization and speech discrimination in a noisy setting. Careful review of the middle ear status, ossicular mass, position of the facial nerve, formation of the cochlea, and vestibular structures on CT scan helps the otologic surgeon determine candidacy for atresia repair.

If the patient is considered to be a favorable candidate, atresia repair should be performed after completion of microtia reconstruction. Patients with bilateral microtia and normal bone conduction thresholds may benefit from bone conduction hearing aids. Bone-anchored hearing aids may be considered in children older than 5 years of age.

With regard to the pinna, the patient and family are presented with three options: observation; prosthetic management, either adhesive- or implant-retained; and reconstructive options including staged reconstruction with autologous rib graft, and reconstruction with linear high-density polyethylene (Medpor) surgical implant material and temporoparietal fascial flap. Generally, observation is recommended until the child is at least 5 to 8 years old. This allows both growth of the donor rib cartilage and development of the contralateral normal ear, which will act as a template for the microtic side. Waiting until the child is older may reduce the risk of the development of a thoracic deformity as a result of harvesting of cartilaginous rib graft, although we feel this risk is minimal.²² Finally, waiting until the child is school-aged allows the child to participate in these important decisions. We feel that it is important for the child to understand the options and participate in the decision making. The general health of the child is assessed, with particular attention paid to growth, maturation, and lung function. It is important to assess lung function, because the risk of pneumothorax and postoperative atelectasis and pneumonia is significant. This assessment usually is performed by the child’s pediatrician. It is important to question the child about his or her personal concerns and to inquire about the effects of the microtia on social interaction with friends and classmates. Each child and parent will have different concerns that should be explored preoperatively.

During the planning stage of reconstruction, the surgical benefits, risks, and alternatives are discussed with the patient and the parents (Table 192-1). Complications such as infection, bleeding, scarring, graft loss, displacement or resorption, asymmetry, and pneumothorax should be discussed in detail. The possibility of a less-than-optimal aesthetic result also is discussed, and the expectations of the patient, parents, and surgeon must be realistic and clearly defined. Providing postoperative photographs of previous patients often is helpful to patients if the pictures depict a realistic result of a similar deformity.

One alternative for older children or adults may be the use of an auricular prosthesis. In some institutions, placement of a permanent auricular prosthesis with osseointegrated implants is recommended as the primary management modality. The aesthetic appearance often is excellent. However, most reconstructive surgeons discourage the use of osseointegrated implants for younger patients as a primary modality for several reasons: The implant sites will require daily care to maintain the health of the soft tissue surrounding the percutaneous osseointegrated implants. The prosthesis needs to be removed at night and replaced in the morning. The patient may unnecessarily avoid situations that may accidentally dislodge the ear and cause embarrassment. The placement of the osseointegrated implants requires removal of the soft tissue with skin grafting to bone to create nonmobile skin surrounding the posts. This eliminates the possibility of reconstructive surgery in the future. Furthermore, the prostheses are expensive and often not covered by third-party payers, leaving the patient at risk for having the osseointegrated implants in place without a prosthesis to wear in the future.

Finally, other materials for auricular reconstruction should be mentioned as part of a thorough informed consent, even if your institution may not offer these types of reconstructions. Implantable materials such as Medpor are used as alternatives to autogenous cartilage. Use of synthetic frameworks eliminates the need to harvest and carve the rib. However, the likelihood of extrusion and the lifelong risk of infections may outweigh their benefit. Stem cell technology is still emerging, and stem cell–derived implants may someday replace the need for rib graft harvesting. To date, no reliable cartilage implant created from stem cells is available.

Autogenous Costochondral Reconstruction

The use of rib cartilage in auricular reconstruction was pioneered by Tanzer²³ and refined by the meticulous work and accomplishments of Brent.^24,25 Reconstruction using the standard rib-grafting technique requires three to four stages, each separated by 2 to 6 months, beginning when the patient is approximately 6 to 8 years old.

The surgeon must develop carving and sculpting skills before undertaking a microtia reconstruction on a patient. For obvious reasons, fresh cadaveric rib cartilage is the best material with which to practice carving and harvesting grafts. If this cannot be obtained, carving the basic auricular framework can be practiced using soap or potatoes.

The surgical procedure described next is appropriate for reconstruction in patients with the most common class III dysplasia, or “peanut” ear.

Classic Microtia Reconstruction

Stage I: Cartilage Implantation

The first stage of microtia reconstruction is undoubtedly the most tedious and crucial of the entire process.²⁴ One of the most important objectives during the first stage is to place the auricular framework in a position that achieves the best symmetry for the patient’s face. Placement of the reconstructed ear is determined by the position of the normal ear, and we do not alter this position to accommodate future reconstruction of the canal atresia or a low-lying hairline. If the hairline is low, the initial ear reconstruction is destined to have hair along the helix that will require depilation or excision at a later date. Preoperative tissue expansion to increase the amount of non–hair-bearing skin is not recommended, because the expanded skin capsule does not contour well over the implanted cartilaginous framework.

Three templates are made using radiographic film: a positioning template, a sizing template, and a carving template. The positioning template is made by carefully tracing the contour of the normal ear. It has the outline of the normal ear, with the landmarks of the lateral palpebral fissure and the lateral oral commissure for reference points. The landmarks are etched onto the radiographic film with an 18-gauge needle or scalpel to avoid losing these reference points (Fig. 192-6). The distance from the lateral palpebral fissure to the root of the helix is also measured on the template and should approximate 6.5 cm, or the length of the normal ear. The sizing template, which is a tracing of the entire ear, is used to test the size of the skin pocket in which the cartilaginous framework is placed. The carving template is drawn from the sizing template to include the landmarks of the antihelix, the triangular fossa, the scaphoid fossa, the medial aspect of the helix, and the antitragus. It is drawn 1 to 2 mm smaller than the sizing template to compensate for the thickness of the overlying skin. It is also used to determine the best donor site during rib harvesting and as a template for sculpting the cartilaginous framework. After the landmarks are permanently etched, the templates are autoclaved. The entire head and neck region is prepared so that the contralateral normal side can be easily visualized to evaluate symmetry. The eyes and mouth are covered with a transparent drape to allow visualization of the lateral palpebral fissure and the lateral commissure and to facilitate placement using the positioning template. The recipient ear site is injected with lidocaine with epinephrine to assist with hemostasis, and the incision is drawn along the anterior and superior margin of the rudimentary lobule. The contralateral side of the chest is prepared, because the contralateral rib graft has better contour characteristics. The chest incision is drawn just superior to the margin of the rib cage.

Figure 192-6. Templates for reconstruction. The positioning template, which is drawn with reference landmarks, is used to create the sizing and carving templates. The sizing template is drawn to match the exact size of the normal ear. The carving template is slightly smaller than the sizing template to compensate for the thickness of the skin flap.

We generally use two surgical teams to reduce operating time. The donor site incision is made on the contralateral side of the chest, and the inferior margin of the rib cage is exposed. We have refined a minimally invasive technique, using a 2-cm skin incision (Fig. 192-7A). Two cartilaginous segments are required: a segment of free-floating cartilage to create the helical rim and a portion of synchondrosis to create the auricular framework.

Figure 192-7. The donor site. A, A minimally invasive 2-cm incision is used to harvest rib segments. B to D, The contralateral chest is chosen for the donor site. The sixth, seventh, and eighth ribs and the synchondrosis between the sixth and seventh ribs are depicted. (The longer incision depicted in C is rarely necessary.) The donor sites of the auricular framework and the helical rim are indicated.

The floating eighth rib is isolated, and dissection is continued posterolaterally to the bony-cartilaginous junction. Ideally this segment is 8 to 9 cm in length. Then the synchondrosis, usually between sixth and seventh ribs, is exposed. The carving template is used to determine the best donor site for the synchondrosis (see Fig. 192-7B to D). The rib cartilage is harvested with the superficial perichondrium intact. After removal of both segments, the donor site is checked for violation of the pleura. The chest wound is filled with saline and the anesthesiologist is asked to deliver positive-pressure ventilation to sustain a pressure of 40 cm H₂O. If a defect in the pleura is identified, a red rubber catheter is introduced into the pleural space and placed on continuous suction. The catheter is removed during positive-pressure ventilation, and the wound is closed with an airtight closure. A suction drain is placed in the subcutaneous space after closure of the rectus muscle. Intercostal bupivacaine blocks are placed at the end of the procedure to reduce postoperative pain.

All incision planning should take into consideration future stages of reconstruction. The recipient incision is made vertically along the anterosuperior margin of the lobule. This incision site will be used for the second-stage lobule transfer. The rudimentary cartilage segment is meticulously removed, with great care taken to avoid perforating or traumatizing the skin flap. The recipient pocket is elevated over the mastoid in a subcutaneous plane. The flap is thinned to a uniform thickness. In the hair-bearing region, the skin is thicker, because it becomes continuous with the scalp and contains a layer of galea. Dissection must be superficial to this layer of galea so that the flap remains uniformly thin and pliable. The sizing template is used to ensure that the pocket is large enough to accommodate the framework. The sizing template reduces the number of times that the reconstructed cartilage framework is transferred in and out of the pocket while adjustments are made; this helps reduce the amount of unnecessary handling and the risk of fracturing the framework.

The framework and helix are carved using Nos. 10, 11, and 15 scalpel blades. The 6700 Beaver blade can also be used (Fig. 192-8). As much perichondrium as possible is left intact over the lateral surface to enhance revascularization and tissue fixation. Suture or wire fixation is needed occasionally to reinforce the synchondrosis and to provide additional support to the framework. Additional cartilage grafts can be sutured to the posterior surface of the synchondrosis for more rigidity. The helix is carved from the eighth rib using the thicker part of the graft for the root of the helix and the thin distal tip of the graft for the caudal helix. The graft is carefully thinned until it is pliable enough to bend around the framework, and it is sutured into position with 4-0 clear nylon sutures. Additional thinning of the scaphoid and triangular fossa can be done after the helix is adequately fixated (Fig. 192-9A to C).

Figure 192-8. A 6700 Beaver blade is used to carve the framework.

Figure 192-9. Construction of the implant. A, The framework is carved from the sixth and seventh ribs. The helix is carved from the eighth rib and is bent gently around the framework. B, The helix is secured with 4-0 clear nylon or wire. C, The implant is compared with the template.

The reconstructed framework with attached helix is then placed into the pocket in a rotational manner, beginning with the root of the helix and then rotating the framework clockwise for the right side and counterclockwise for the left. If the pocket is excessively tight and the overlying skin remains blanched with poor vascular refill, the implant is removed and the pocket enlarged. After the graft is properly positioned, a small round suction drain is placed deep to the framework and brought out through the skin in the hairline. After the wound is sealed, the skin should conform to the framework, and the details of the helix and antihelix should be clearly visible (Fig. 192-10). The concavities of the ear are packed with petroleum gauze and secured with 4-0 chromic bolster sutures. A Glasscock dressing is applied using fluffed gauze to avoid unnecessary pressure. The drains are placed on intermediate suction. One of us (CSM) prefers continuous suction for 24 hours before placing the drains on bulb suction; another (VQ) recommends the continuous use of butterfly drains connected to vacuum-sealed red rubber–topped tubes.

Figure 192-10. Placement of the implant. The implant is placed into the pocket and positioned using the positioning template. One drain is placed over the surface of the implant as one is placed deep to the implant. The drains are then placed on suction. Note the contouring of the skin over the cartilaginous framework, with the drain traversing over the antihelix and into the scaphoid fossa.

A chest radiograph is obtained in the recovery room to rule out the possibility of pneumothorax. These patients are admitted for 48 hours for pain control, and intravenous antibiotics. The chest drain is removed on the first postoperative day, and the ear drain is removed after 2 to 3 days when there is little or no drainage. The vascularity of the skin overlying the helix is inspected on a regular basis, and the mastoid dressing is removed at 24 to 48 hours. A Glasscock dressing is then applied for the next 2 weeks to protect the ear. The patient must refrain from strenuous activity for 4 to 6 weeks, and the patient is not allowed to participate in contact sports for 1 month to avoid injuring the donor rib site.

Stage II: Lobule Transfer

The second surgery is performed 2 to 3 months after the first stage. A transposition flap is designed to move the vertically oriented lobule to the tail of the framework. After the incisions are made, a pocket is created within the lobule to accommodate the tail of the framework. The tail is elevated from the mastoid cortex so that the lobule can be wrapped around the posteroinferior margin of the cartilage framework. Care is taken to evert the wound margins in an attempt to avoid a stepoff at the junction of the lobule and framework. One to two Z-plasties are performed across the transverse portion of the incision (Fig. 192-11A to F).

Figure 192-11. Stage II lobule transfer. A, Preoperatively, the lobule is noted to be malpositioned anteriorly. B, A lobule transposition flap incision is drawn. C, Lobule is elevated and posteroinferior margin of the framework is dissected out. D, A pocket is dissected within the lobule, and the lobule is transposed over the posteroinferior margin of the graft. E, Suture is placed from the pocket in the lobule to mastoid periosteum in order to reduce the flare of the lobule. F, Several mini Z-plasties are created along the incision to break up the scar and prevent contracture. Incisions are closed with mattress sutures.

Stage III: Creation of Postauricular Sulcus

This procedure is performed approximately 3 months after stage II (Fig. 192-12A to D). An incision is made around the helical rim. However, if there is hair on the helix, the incision is made slightly lower on its lateral surface to minimize the hair-bearing skin over the framework. The non–hair-bearing auricular skin is advanced 2 to 3 mm superiorly over the helical rim, and absorbable tacking sutures are placed between the subcutaneous tissue and the cartilaginous framework. The ear is released by dissecting into the postauricular sulcus and leaving the perichondrium intact to protect the cartilage graft. The postauricular skin over the mastoid is undermined and advanced into the postauricular sulcus, to help project the ear laterally away from the mastoid. After the postauricular skin is advanced and secured, the remaining defect is measured. It usually measures approximately 4 × 8 cm². An elliptical thick split-thickness graft is harvested freehand from the left groin. The donor site is closed primarily. The graft is secured into the newly created postauricular sulcus with 5-0 chromic sutures. A bolster is secured into the sulcus with a 4-0 nylon. The ear is covered with a Glasscock dressing for protection for 1 to 2 weeks. The bolster is removed after 5 to 7 days, and the skin graft is kept moist for 2 to 3 weeks.

Figure 192-12. Stage III skin grafting. A, Before the procedure. B, Release of the skin, leaving the perichondrium intact. Dissection is carried into the postauricular sulcus, and postauricular skin is advanced. C, Skin graft in place. D, Skin graft secured with a soft bolster.

For some patients, the contralateral ear is prominent, contributing to the asymmetrical appearance of the ears. Otoplasty of the normally formed ear can be combined with this procedure, and the skin excised for the otoplasty can be used for grafting of the newly created postauricular sulcus of the microtic ear.

Stage IV: Tragus Reconstruction

The fourth stage of reconstruction is to form a tragus and conchal bowl. If the conchal bowl is well defined, a composite graft can be used to reconstruct the tragus. An elliptical composite graft is removed from the concha cymba of the contralateral ear. An incision is made along the posterior border of the future tragus, and the composite graft is placed on the posterior surface to give the tragus some projection. The shadowing effect gives the illusion of an external auditory meatus. If the conchal bowl is not defined, an incision is made along the posterior border of the future conchal bowl, and an anterior-based cutaneous circular flap is created. The conchal bowl is then debulked of scar tissue and any rudimentary skin and cartilage that might remain. Because of facial nerve anomalies, a facial nerve monitor is recommended. The flap is folded onto itself to create a tragus that is then reinforced with a small piece of auricular or rib cartilage, and the surface of the conchal bowl is covered with a small skin graft (Fig. 192-13A to C). The bolster is removed in 3 to 5 days. Occasionally, an additional operation is needed to further elevate the reconstructed ear away from the mastoid using grafts of cartilage implanted medial to the framework.

Figure 192-13. Stage IV tragus reconstruction. A, In bilateral microtia, tragal reconstruction is more difficult, because both ears are reconstructed; thus, normal concha cymba is not available for composite grafting. A longer flap must be elevated to provide both medial and lateral tragal lining. B, A free cartilage graft is placed to prevent contraction and is lined by the skin flap. C, The conchal bowl is deepened and lined with a skin graft.

(From Quatela VC, Goldman ND. Microtia repair. Facial Plast Surg. 1995;11:257. Used with permission.)

Atypical Microtia Repair

Second-degree dysplasia or atypical microtia presents a more difficult surgical challenge. As previously discussed, many components of the auricular structure are recognizable, but there is a distinct tissue deficiency that necessitates the transportation of cartilage and skin. The additional structure often eliminates the necessity for complete framework insertion. When the vertical height difference between the two ears is greater than 20 mm, consideration is given to using a rib framework. When the difference is less than 20 mm, the result is achieved by expanding the existing structure; this is done by a combination of unfurling, uncupping, and increasing the vertical height with the use of cartilage composite grafts (Fig. 192-14A to H).²⁶ The helical root can also be advanced in a V-Y fashion into the helix to help augment the vertical height. Unlike classic microtia reconstruction, the use of vestigial remnants as a main framework does not lead to consistent results. Figure 192-15A to F shows a child with atypical microtia with an undeveloped lobule that was reconstructed by placing a cartilage implant that was harvested from the contralateral conchal bowl. This reconstruction was followed by a staged skin graft with an advancement flap of postauricular skin.

Figure 192-14. Atypical microtia reconstruction. A, A congenital defect of the ear with more than 20 mm of vertical height than in the contralateral healthy ear. B, The donor site composite graft is harvested to equal to one-half the size of the recipient defect, thereby reducing the disparity. The donor site is closed primarily, with the only resultant deformity being shortened vertical height, which is desirable in this patient’s ear. C, The donor ear is shortened by 1 cm but retains good form. D, The composite graft. E, The composite graft sutured into position; vertical height is increased by approximately 1 cm. F, Epithelium is removed from the medial aspect of the composite graft, and the graft placed into a postauricular subcutaneous pocket. The medial skin is still attached at the rim as a hinge flap. The medial perichondrium is in contact with the retroauricular soft tissue; this will ensure maximum recipient contact for graft survival. Release is accomplished 2 weeks later, using the hinge flap skin for medial resurfacing. G, Before surgery. H, The final result at 1 year.

Figure 192-15. A and B, Type II atypical microtia with a missing lobule and a dysmorphic helix and antihelix. C to E, Two-stage reconstruction required placement of a conchal cartilage graft followed by delayed release of the lobule, advancement of postauricular skin, and placement of a full-thickness skin graft that was secured with a bolster dressing. F, Final postoperative result at 1 year.

Figure 192-16. A, Type III microtia with anteriorly positioned lobule. B to F, At 2 years after completion of microtia reconstruction. Note the height symmetry and angle of the auricle in relation to Frankfurt horizontal plane.

Complications

Major complications are rare. However, seemingly minor complications may lead to loss of the graft if they are not treated expeditiously. Immediate postoperative complications include pneumothorax and hematoma formation. Short-term complications include skin flap necrosis and infection. If a graft becomes exposed postoperatively secondary to breakdown of the overlying skin flap, the patient is placed on antibiotics that provide coverage for Staphylococcus and Pseudomonas infections, and the exposed site is covered with moist continuous dressings. If the exposure is small (1 to 2 mm) and the perichondrium is intact, the wound may granulate with local wound care. If the perichondrium is gone and the cartilage exposed, the framework may become devitalized, desiccated, and infected. Early coverage of the site with a local flap or a temporoparietal fascia flap with an overlying skin graft should be considered. Prolonged antibiotic therapy after flap coverage is necessary to avoid progression of the infection and eventual collapse and resorption of the graft.

Minor complications include malpositioning, scar contracture or hypertrophy, and poor contouring. Generally, problems with scar formation and poor contouring resolve with time if the cartilage has not become infected or undergone resorption. Minor scar revisions may be necessary when indicated, and the surgeon should be careful not to expose the cartilage graft. Problems with malposition are usually minor if proper template techniques were used, and they are commonly related to preexisting lobule asymmetry or generalized facial asymmetry caused by hemifacial microsomia. Major malposition problems are usually related to poor preoperative planning.

Conclusions

Managing patients with microtia can be a rewarding experience for both the patient and the surgeon if proper training, preparation, and planning are done. Each patient and each ear deformity are unique, thus making the management of these patients a humbling, challenging, and perpetually stimulating problem. In many respects, microtia surgery is similar to rhinoplasty, in which the surgeon continually strives to achieve the elusive “perfect” aesthetic and functional result through meticulous planning and attention to detail.