Journal Logo

Pediatric/Craniofacial: Original Articles

Review of 602 Microtia Reconstructions: Revisions and Specific Recommendations for Each Subtype

Kim, Ara M.D.; Lee, Hojune M.D.; Oh, Kap Sung M.D., Ph.D.

Author Information
Plastic and Reconstructive Surgery: July 2020 - Volume 146 - Issue 1 - p 133-142
doi: 10.1097/PRS.0000000000006906
  • Free
  • Editor's Pick

Abstract

Congenital microtia is a rare but immediately visible defect of the external ear that leads to concerns and frustration for patients and their families.1,2 Auricular reconstruction is one of the most challenging facial plastic surgery procedures because of the complexity of the three-dimensional, symmetrical, and bilateral placement of the ear. Since the introduction of autologous costal cartilage graft techniques by Tanzer, Brent, Nagata, Firmin, and Park et al.,3–7 successful long-term experiences have been frequently reported.8–11 Nagata’s two-stage technique and his classification12–14—lobule and concha types—have been widely accepted, but there are still many others to consider. Adverse local conditions of the recipient site, including skin volume deficiency, atypical shape or location of the vestige, and hypoplasia of the facial skeleton and soft tissue make procedures technically challenging. Technical modifications and minor revisions on the reconstructed ear vary significantly between institutions because of the patient-specific local conditions.15,16

In addition to aesthetic considerations, the functional aspects of congenital microtia require surgical attention. Isolated microtia may be induced by embryologic disruption of the first and second branchial arch derivatives, resulting in problems associated with hearing and a hemifacial appearance.17–19 A significant percenage of children with microtia also present with atresia or stenosis of the external auditory canal (90 percent), leading to conductive hearing loss at the microtia side.20,21 Canaloplasty is performed to overcome the hearing loss but reportedly bears a high risk of postoperative complications, including prolonged discharge and canal narrowing.22 For bilateral patients, hearing restoration is the major concern that needs to be addressed to prevent speech and language skill development delay.23 However, for unilateral microtia patients, the importance of hearing is less, because of the patients’ functional hearing at the contralateral side. Surgical correction of hemifacial microsomia is also controversial. Although the invasive corrections would improve facial aesthetics and dental occlusion of microtia patients, a high rate of adverse events has been reported; potential risks seem to outweigh the potential advantages.24,25

Because of the large variation in phenotype and functional presentation, the optimal treatment plan for correction of congenital microtia remains unclear. We thus evaluated how surgical revisions and interdisciplinary interventions were involved in microtia reconstruction. The challenges and adjustments expected for each subtype (i.e., anotia, small/atypical but usable lobule, typical lobule, concha, and scapha type) are suggested to achieve optimal results.

PATIENTS AND METHODS

After approval of the Samsung Medical Center Institutional Review Board (Seoul, Republic of Korea), all patients provided written informed consent befre the present study. Congenital unilateral microtia patients who underwent two-stage Nagata auricular reconstruction from June of 2001 to June of 2019 were retrospectively reviewed based on an electronic chart review. Bilateral microtia patients were excluded from this study. Patient variables (including sex, age at the time of surgery, laterality, type of microtia, presence of hemifacial microsomia, and follow-up period), surgical variables, and postoperative complications were reviewed. Microtia type was assigned based on the Nagata classification but subsequently further categorized in order of increasing volume of vestige—anotia, small/atypical but usable lobule, typical lobule, concha, and scapha type—in accordance with the report by Park and Park.16

Surgical variables included the type, number, and timing of surgical revisions. Aesthetic revisions referred to additional operations performed to improve the aesthetics of the reconstructed ear. Further elevation referred to surgical revisions performed to define or enhance the postauricular projection. Therapeutic revisions referred to surgical procedures performed to treat postoperative complications. The number and timing of canaloplasties and jaw operations were reviewed to evaluate the interdisciplinary involvements by the otorhinolaryngology and dentistry departments, respectively. Jaw operations included both soft-tissue (e.g., free tissue transfer) and skeletal corrections (e.g., two-jaw operations). Other surgical variables included the use of a tissue expander.

Over the 20-year period, the two stages of microtia reconstruction were performed: framework fabrication, implantation, and simultaneous lobule rotation at the first stage and auricular elevation at the second stage. Minor modifications have been described previously.26,27

Differences among the microtia subtypes were investigated as appropriate with a two-tailed t test and the Kruskal-Wallis test for continuous variables, and by the Fisher’s exact test for categorical variables. Statistical analyses were performed using IBM SPSS Version 24 (IBM Corp., Armonk, N.Y.). A value of p < 0.05 was considered statistically significant.

RESULTS

After exclusion of 26 bilateral cases, 602 congenital, unilateral microtia patients underwent the two-stage auricular reconstruction; patients were predominantly male patients and the right side was the predominant side. The mean patient age at the time of the first stage was 12.3 years (range, 6 to 55 years). Most cases were classified as typical lobule [n = 298 (49.5 percent)] and concha [n = 173 (28.7 percent)], followed by scapha [n = 68 (11.3 percent)], small/atypical but usable lobule [n = 57 (9.5 percent)], and anotia [n = 6 (1.0 percent)]. Hemifacial microsomia was seen in 211 patients (35 percent). The mean follow-up period was 4.9 years (range, 0.6 to 17.4 years) (Table 1).

Table 1. - Patient Characteristics
Variable Value (%)
Total no. of patients 602 (100)
Sex
Male 395 (65.6)
Female 207 (34.4)
Laterality
Right 353 (58.6)
Left 249 (41.4)
Age at first-stage surgery, yr
Mean ± SD 12.3 ± 6.1
Range 6–55
Type
Anotia 6 (1.0)
Small/atypical lobule, but usable 57 (9.5)
Lobule 298 (49.5)
Concha 173 (28.7)
Scapha 68 (11.3)
Presence of HFM 211 (35.0)
Total follow-up, yr
Mean ± SD 4.9 ± 3.1
Range 0.6–17.4
HFM, hemifacial microsomia.

Overview of Interventions for Each Subtype of Microtia

In total, 407 patients (67.6 percent) underwent some form of revision and/or interdisciplinary interventions (including tissue expansion, aesthetic revision, further elevation, therapeutic revision, canaloplasty, or jaw/soft-tissue surgery), in addition to the two stages of microtia reconstruction (average number, 2.2; range, 1 to 11). Regarding the subtype of microtia, statistically significant differences were found between the types of interventions commonly performed (tissue expansion, p = 0.000; canaloplasty, p = 0.000; and aesthetic revision, p = 0.016). The use of a tissue expander appeared to decrease with the increasing volume of vestige. All anotia patients required a tissue expander, whereas the percentage using a tissue expander was lowest for scapha cases (16.2 percent). In small/atypical but usable lobule cases, 40.4 percent underwent aesthetic revisions to improve contour or transpose undercorrected, low-set lobules. Canaloplasty was mostly performed on the lobule type, followed by concha and scapha, whereas the majority of anotia and small/atypical lobule types were poor candidates for canaloplasty (Fig. 1, above). No significant differences were observed with other types of interventions (Fig. 1, below).

Fig. 1.
Fig. 1.:
Flow sheet with the type, overall timing, and total number of interventions for each microtia subtype. TE, tissue expander. Categorical variables are represented by patient number (percent), and continuous variables are represented by the mean and standard deviation. *Statistically significant. †Significant: anotia versus small/atypical lobule, lobule, concha, or scapha. Small/atypical lobule versus concha or scapha. ‡Significant: lobule versus small/atypical lobule, concha versus small/atypical lobule, scapha versus small/atypical lobule. §Significant: small/atypical lobule versus lobule. ‖The timing of each intervention may vary, but the most common timing was described.

With respect to the average number of total interventions, statistically significant differences were not found among subtypes, ranging from 1.2 to 2.5 (p = 0.127). Although the common type of interventions were different among subtypes, the number seemed comparable. Aesthetic revision, further elevation, and canaloplasty were performed less than twice on average for all subtypes (Table 2).

Table 2. - Average Number of Interventions Performed for Each Subtype of Microtia
Anotia (%) Small/Atypical but Usable Lobule (%) Lobule (%) Concha (%) Scapha (%) p
No. of patients 6 57 298 173 68
Tissue expansion
No. of patients 6 (100) 19 (33.3) 75 (25.2) 31 (17.9) 11 (16.2) 1.000
Mean ± SD 1.0 ± 0.0 1.1 ± 0.2 1.0 ± 0.2 1.0 ± 0.2 1.0 ± 0.0
Range 1–1 1–2 1–2 1–2 1–1
Aesthetic revision
No. of patients 1 (16.7) 23 (40.4) 62 (20.8) 51 (29.5) 20 (29.4) 0.823
Mean ± SD 1.0 1.3 ± 0.6 1.3 ± 0.5 1.3 ± 0.5 1.5 ± 0.8
Range 1–1 1–3 1–3 1–3 1–3
Further elevation
No. of patients 0 (0.0) 7 (12.3) 48 (16.1) 22 (12.7) 12 (17.6) 0.393
Mean ± SD N/A 1.1 ± 0.4 1.2 ± 0.5 1.1 ± 0.3 1.3 ± 0.5
Range N/A 1–2 1–3 1–2 1–2
Therapeutic revision
No. of patients 0 (0.0) 9 (15.8) 42 (14.1) 26 (15.0) 4 (5.9) 0.592
Mean ± SD N/A 2.0 ± 1.6 1.5 ± 1.0 1.7 ± 1.0 2.8 ± 2.1
Range N/A 1–5 1–5 1–5 1–5
Canaloplasty
No. of patients 0 (0.0) 2 (3.5) 133 (44.6) 59 (34.1) 18 (26.5) 0.151
Mean ± SD N/A 1.0 ± 0.0 1.3 ± 0.6 1.3 ± 0.5 1.6 ± 0.7
Range N/A 1–1 1–4 1–3 1–4
Jaw surgery
No. of patients 0 (0.0) 4 (7.0) 5 (1.7) 2 (1.2) 1 (1.5) 0.109
Mean ± SD N/A 2.3 ± 1.3 1.0 ± 0.0 1.5 ± 0.7 2.0 ± 0.0
Range N/A 1–4 1–1 1–2 2–2
Total interventions, if any
No. of patients 6 (100) 39 (68.4) 204 (68.5) 119 (68.8) 39 (57.4) 0.127
Mean ± SD 1.2 ± 0.4 2.2 ± 1.9 2.3 ± 1.6 2.1 ± 1.3 2.5 ± 1.6
Range 1–2 1–10 1–11 1–6 1–7
N/A, not applicable.

Aesthetic Revision

In total, 157 patients (26.1 percent) underwent aesthetic revisions for reconstructed ears. The lobule region most frequently required minor corrections. The scapha/triangular fossa region, including the superior or inferior crus of antihelix, was the least common compartment requiring revision (Table 3). Of 157 patients, 127 (80.9 percent) underwent aesthetic revisions at a mean of 3.1 years (range, 0.4 to 15.7 years) after the second stage, and 30 patients (19.1 percent) underwent revisions following the first stage, with a mean postoperative time of 1.2 years (range, 0.1 to 4.2 years).

Table 3. - Specific Locations of Aesthetic Revisions *
No. of Patients (%)
Lobule 79 (50.3)
Helix 60 (38.2)
Tragus 46 (29.3)
Concha 43 (27.4)
Scapha/triangular fossa 15 (9.6)
*n = 157 patients; multiple locations were revised in some patients.

Further Elevation

Additional definition or elevation of the postauricular projection was performed in 89 of 602 patients (14.8 percent). The inferior sulcus, where the helix-to-lobule transition area was usually located, was the region of highest demand for surgical corrections. Of 89 patients, 19 (21.3 percent) underwent a groin donor full-thickness skin graft to further elevate the entire projection under general anesthesia (Table 4). Further elevations were performed, with a mean postoperative period of 3.2 years (range, 0.1 to 10.9 years) after the second stage.

Table 4. - Specific Locations of Further Elevation *
No. of Patients (%)
Correction of inferior sulcus by adjacent donor 50 (56.2)
Correction of superior sulcus by adjacent donor 18 (20.2)
Correction of inferior sulcus by remote donor 12 (13.5)
Correction of superior sulcus by remote donor 4 (4.5)
Elevation of the entire projection by groin FTSG 19 (21.3)
FTSG, full-thickness skin graft.
*n = 89 patients.
†Adjacent donor referred to Z-plasties, local rotation flap, transposition flap, V-Y advancement flap, or full-thickness skin graft harvested from redundant auricular tissue.
‡Remote donor referred to full-thickness skin graft harvest from groin, chest, or contralateral ear. Multiple locations were revised in some patients.

Therapeutic Revision

Therapeutic revisions were required in 81 of 602 patients (13.5 percent) to treat postoperative complications. Framework exposure, or skin flap necrosis, was the most common, and skin graft loss was the second most common reason for postoperative complications, with incidence rates of 4.0 percent and 3.3 percent, respectively. The incidence of the two major complications seemed highest in concha type patients (Table 5). Laser treatment was performed on 486 patients (80.7 percent) for treatment of low hairlines, with the average number ranging from 2.4 to 3.6 cycles. There was no statistically significant difference between subtypes (p = 0.077).

Table 5. - Specific Reasons for Therapeutic Revisions and the Incidence Rates per Population *
Anotia (%) Small/Atypical but Usable Lobule (%) Lobule (%) Concha (%) Scapha (%) Total (%) p
No. 6 57 298 173 68
Skin flap necrosis (framework exposure) 0 (0) 1 (1.8) 12 (4.0) 9 (5.2) 2 (2.9) 24 (4.0) 0.831
Skin graft loss 0 (0) 1 (1.8) 9 (3.0) 9 (5.2) 1 (1.5) 20 (3.3) 0.596
Infection 0 (0) 3 (5.3) 4 (1.3) 6 (3.5) 1 (1.5) 14 (2.3) 0.249
Hematoma 0 (0) 1 (1.8) 3 (1.0) 4 (2.3) 0 (0) 8 (1.3) 0.515
Framework resorption 0 (0) 1 (1.8) 3 (1.0) 2 (1.2) 0 (0) 6 (1.0) 0.798
Hypertrophic scar 0 (0) 0 (0) 2 (0.7) 2 (1.2) 0 (0) 4 (0.7) 0.861
*n = 602; multiple complications were combined in some patients.

Timing of Interdisciplinary Operations

The mean time interval between the first and second stages ranged from 1.8 to 2.0 years; follow-up ranged from 3.2 to 5.0 years. The timing of the canaloplasty was predominantly between the first and second stages of microtia reconstruction. A small number of patients underwent jaw/soft-tissue operations to correct or compensate hemifacial microsomia, ranging from 0 to 7 percent. The timing of jaw operations appeared to be inconsistent among subtypes, with a slightly higher predominance after the second stage (Table 6).

Table 6. - Timing of Interdisciplinary Interventions
Anotia (%) Small/Atypical but Usable Lobule (%) Lobule (%) Concha (%) Scapha (%)
Interval between the two stages, yr
Mean ± SD 2.0 ± 1.1 1.8 ± 0.9 2.0 ± 1.3 1.9 ± 1.4 1.8 ± 1.1
Range 0.8–3.6 0.5–5.1 0.3–8.6 0.4–9.9 0.2–4.6
Canaloplasty
Before the first stage 0 (0) 0 (0) 1 (0.3) 9 (5.2) 1 (1.5)
Between the two stages 0 (0) 0 (0) 83 (27.9) 32 (18.5) 9 (13.2)
After the second stage 0 (0) 2 (3.5) 49 (16.4) 18 (10.4) 8 (11.8)
Jaw operations
Before the first stage 0 (0) 0 (0) 2 (0.7) 1 (0.6) 0 (0)
Between the two stages 0 (0) 2 (3.5) 0 (0) 0 (0) 1 (1.5)
After the second stage 0 (0) 2 (3.5) 3 (1) 1 (0.6) 0 (0)
Follow-up, yr
Mean ± SD 3.2 ± 2.2 4.9 ± 3.7 4.8 ± 2.9 5.0 ± 3.1 4.9 ± 3.2
Range 1.1–7.0 1.1–17.4 0.8–16.9 0.9–13.2 0.6–12.4

DISCUSSION

Type-Specific Strategies to Minimize Skin Flap Necrosis

The two stages of Nagata’s technique have been popularized as the standard for autologous auricular reconstruction. However, minor technical variations are indispensable because of the highly variable local conditions of microtia patients. Despite the variations, some fundamental principles exist—preserving a reliable subcutaneous pedicle,12,28 afflicting minimal trauma to the framework and subdermal vascular plexus, and ensuring sufficient recovery time for the traumatized tissue—to prevent the most disastrous sequence of complication: skin envelope necrosis, subsequent exposure of framework, cartilage infection, and deformity/resorption of reconstructed auricle. In our two-decade cohort study, revision and interdisciplinary operations were differently used for each subtype, with a low incidence of framework exposure (4.0 percent). The differences highlight the level of difficulty in elevating the subcutaneous pedicle for each subtype, the economic use of vestige volume, and the percentage of patients requiring protective strategies against later effects of canaloplasty or other circulation-threatening procedures. Accordingly, we present here microtia type-specific recommendations for safe and reliable microtia reconstruction.

Anotia

All six unilateral anotia patients underwent tissue expansion before framework implantation to overcome the soft-tissue deficiency. The tissue expander–based auricular reconstruction can be unsatisfactory because of the increased risk of skin flap necrosis.29 Poor convolution derived from the thick capsule of the expander can also be aesthetically displeasing. However, total capsulectomy is controversial and technically dangerous, increasing the risk of hematoma or threatening the cutaneous vascular supply.9 Disruption of the cutaneous vascular network is especially problematic in anotia patients because the subcutaneous pedicle cannot be detected in this group. To minimize damage to the cutaneous vascular supply, we placed the expander from a vertical scalp incision ending at the imaginary location of the superior helix (Fig. 2, left). The expander capsule was left intact after expander removal. The cartilage framework was implanted from the same incision with good skin–cartilage contact using negative suction drainage. With long-term follow-up, the thick capsule seemed to be resorbed and have thinned spontaneously to some extent. The final auricular contour was satisfactory and did not require further aesthetic revisions (Fig. 2, right). All anotia patients were poor candidates for canaloplasty, as characterized by the hypoplastic middle ear cavity and underdevelopment of the auditory nerve.

Fig. 2.
Fig. 2.:
(Left) A 38-year-old male patient with unilateral anotia. A 45-cc rectangular tissue expander was placed from a vertical scalp incision ending at the imaginary location of the superior helix. (Right) Postoperatively, 200 days after auricular elevation.

Small/Atypical but Usable Lobule

Patients with a small/atypical but usable lobule most frequently underwent minor aesthetic revisions. A high percentage of small/atypical lobule patients also presented with hemifacial microsomia [n = 52 (91.2 percent)] and/or a low-set location of vestige [n = 31 (54.4 percent)]. Although the severity of hemifacial microsomia itself may not affect the surgical outcome,16,27 poor cartilage details and aberrant location of the lobule seemed to increase the number of aesthetic revisions required. When the lobule is atypical and low-set, simultaneous lobule transposition with framework implantation can disrupt the subcutaneous pedicle, increasing the risk of skin flap necrosis. In such cases, the lobule was left intact and the framework was implanted without elevating the subcutaneous pedicle (Fig. 3, left). Because the subcutaneous pedicle was not elevated, the flap perfusion would only depend on the horizontal cutaneous vessel network as mentioned previously.6,30 In this situation, the thickness of the subcutaneous pocket was preserved as much as possible to support the cutaneous circulation. Although the thickest flap would result in a blunted contour of the auricle, avoiding skin flap necrosis should be the primary concern. Staged lobule transpositions were performed at later operations (Fig. 3, right). The majority of small/atypical lobule patients, like anotia patients, were also poor candidates for canaloplasty. These results seemed consistent with the high correlation reported between the severity of microtia and the frequency of middle ear anomalies and complications following canaloplasty.20,23

Fig. 3.
Fig. 3.:
(Left) An 8-year-old male patient with a small atypical lobule. The framework was implanted without elevating the subcutaneous pedicle. Simultaneous lobule transposition was not performed. (Right) Postoperatively, 111 days after auricular elevation. Multiple lobule transpositions were performed using a staged approach.

Typical Lobule with or without Canaloplasty

Typical lobule patients constituted the largest group of our study population (49.5 percent), and the subcutaneous pedicle was easily detected in this type of microtia.31 Subcutaneous pedicle preservation is controversial.9,15 Nagata raised a subcutaneous pedicle from deep tissue layers connecting to the auricular skin flap, and Firmin considered the horizontal cutaneous vascular network, rather than the subcutaneous pedicle, as the major blood supply. A laser fluorescence study revealed that the use of both kinds of blood supply was possible.30 In this regard, the auricular pocket for the framework can be created as a bipedicled skin flap, consisting of one subcutaneous pedicle vertically perforating into the skin flap (located at the conchal area) and one cutaneous pedicle running horizontally to the skin flap (coming from the pocket margin). By adding a subcutaneous pedicle, thinning of the skin flap can be more safely performed to allow sharp skin-cartilage coaptation,32 resulting in good long-term convolution of the reconstructed auricle. If a subcutaneous pedicle is absent and the horizontal vascular network is the only source of blood supply, the skin flap would require sufficient thickness. A thin flap without a reliable subcutaneous pedicle would threaten cartilage nutrition and flap viability if followed by dissection of remnant cartilage, removal of redundant hillocks, or a flap trimming procedure.

In this cohort, approximately half of patients with a typical lobule underwent canaloplasty. Some protective strategies for the reconstructed auricles would be needed, given that canal operations may induce vascular injury and scarring at the conchal region.22 At the stage of framework fabrication, a wide conchal bowl was made, providing some room for future tissue contraction and canal formation (Fig. 4). A long interval between operations, with an ideal time of at least 1 year, was also allowed to facilitate recovery.33 At our institution, unilateral microtia patients were routinely sent to otologists after the end of the first stage for hearing evaluation. When the expected success rate of hearing restoration was over 90 percent based on the Jahrsdoerfer criteria,34,35 we recommended canaloplasty before auricular elevation. For such patients, canaloplasty was performed at a mean time of 1.4 years (range, 0.3 to 4.4 years) after framework implantation; the auricle was elevated at a mean time of 1.6 years (range, 0.2 to 5.6 years) after canaloplasty. When the success rate was as low as 50 percent, canal operations were not recommended. To achieve fully perfused soft tissue, canaloplasty candidates need to be strictly managed by microtia surgeons to achieve satisfactory results, both aesthetically and functionally.

Fig. 4.
Fig. 4.:
An 11-year-old male patient with typical lobule type microtia shown postoperatively, 200 days after canaloplasty. Note that large hillocks at the conchal region were still left intact. Soft-tissue removal in the conchal region would be performed after assessing contracture and resorption induced by canaloplasty and/or auricular elevation.

Concha

In terms of therapeutic revision, concha type patients seemed to most frequently experience complications, including framework exposure and skin graft loss. Concha type cases are characterized by a larger volume of cartilaginous structures than lobule type cases, including tragus and incisura intertragica.13,14 It was more challenging to preserve a reliable subcutaneous pedicle in concha type cases, because more meticulous skills were required to dissect the pedicle-containing cartilage remnants.36 The subcutaneous perforators were found coursing over the perichondrium of the conchal wall cartilage, and cartilage dissection needed to be performed with sufficient care to minimize injury to the subdermal plexus and perichondrium.37 After preserving the pedicle-containing conchal cartilage, other cartilaginous parts can be partially removed to adjust to the framework. The skin of the concha was redraped upward to cover the lower margin of the framework. Redundant skin was left intact or very carefully trimmed. Although some surgeons reported that vigorous trimming of the remnant hillocks was safe, because of the presence of a subcutaneous pedicle,36 we found that congestive color change and/or skin flap necrosis was common, especially at the conchal region when vigorous contouring was performed. Maintaining remnant hillocks of the conchal region may be safer, especially in concha-type cases (Fig. 5). The remnant volume can be removed during later aesthetic revisions on an outpatient basis.

Fig. 5.
Fig. 5.:
An 11-year-old male patient with concha-type microtia. Mild erythema was found at the concha and triangular fossa region, suspicious for flap congestion after skin trimming. The color change was resolved spontaneously.

Scapha

Scapha type cases had the largest tissue volume among the groups, with the presence of an extra cartilaginous structure above the concha level. A considerable number of patients underwent aesthetic revisions (29.4 percent), probably because of the presence of large tissue redundancies following the first or second stage of the procedure. Cartilage remnant above the conchal bowl was completely removed to incorporate the framework cartilage; therefore, a large amount of tissue drape remained. Tissue redundancies were commonly found at the root of the helix and the conchal region (Fig. 6). Most of the tissue bulk was left intact and later revised after complete healing following the second stage, for the following reasons. First, the subdermal plexus to the cartilage framework should be maximally preserved because the well-perfused framework is of foremost importance for the entire autologous auricular reconstruction. This seemed especially critical in concha or scapha type cases, where it was technically difficult to preserve the subcutaneous pedicles. Second, redundant skin will be used for full-thickness skin donor in cases of skin graft loss, decreasing the use of remote donor (e.g., groin, chest). Third, the helical root and concha areas were commonly damaged during canaloplasty. Soft-tissue removal in these areas should preferably be performed after circulation-threatening procedures, such as auricular elevation or canaloplasty.

Fig. 6.
Fig. 6.:
A 10-year-old male patient with scapha-type microtia. The low margin of framework was trimmed to adjust to the patient’s conchal cartilage. Tissue redundancies were commonly found at the root of the helix and the conchal region. These were also commonly damaged areas during canaloplasty.

Limitations

Limitations of this study arise from its retrospective design and the data being limited to one institution. To increase objectivity, data collection was confined to the values that had been already digitalized, including date, type, and location of operations and consultation records. The aesthetic outcome for the reconstructed ear was not graded in this study because it can be highly subjective in the setting of retrospective photographic analysis and its standardized means are still unavailable.9 Another limitation of this study was the small number of patients who underwent jaw operations; thus, it was difficult to draw a meaningful conclusion in this regard. Although the results from one institution are not generalizable, our analysis of data from two decades of experience provides a comprehensive review of a large number of unilateral microtia patients from a tertiary referral center, in one country, renowned for its patient safety and satisfaction.

REFERENCES

1. Stallings EB, Isenburg JL, Mai CT, et al.; National Birth Defects Prevention Network. Population-based birth defects data in the United States, 2011-2015: A focus on eye and ear defects. Birth Defects Res. 2018;110:1478–1486.
2. van Hövell Tot Westerflier CVA, Stegeman I, Muradin MSM, Smit AL, Breugem CC. Parental preferences for the first consultation for microtia. Int J Pediatr Otorhinolaryngol. 2018;106:10–15.
3. Tanzer RC. Total reconstruction of the auricle: The evolution of a plan of treatment. Plast Reconstr Surg. 1971;47:523–533.
4. Brent B. Ear reconstruction with an expansile framework of autogenous rib cartilage. Plast Reconstr Surg. 1974;53:619–628.
5. Nagata S. A new method of total reconstruction of the auricle for microtia. Plast Reconstr Surg. 1993;92:187–201.
6. Firmin F. Ear reconstruction in cases of typical microtia: Personal experience based on 352 microtic ear corrections. Scand J Plast Reconstr Surg Hand Surg. 1998;32:35–47.
7. Park C, Lee TJ, Shin KS, Kim YW. A single-stage two-flap method of total ear reconstruction. Plast Reconstr Surg. 1991;88:404–412.
8. Bauer BS. Reconstruction of microtia. Plast Reconstr Surg. 2009;124(Suppl):14e–26e.
9. Wilkes GH, Wong J, Guilfoyle R. Microtia reconstruction. Plast Reconstr Surg. 2014;134:464e–479e.
10. Li Q, Zhou X, Wang Y, Qian J, Zhang Q. Auricular reconstruction of congenital microtia by using the modified Nagata method: Personal 10-year experience with 1350 cases. J Plast Reconstr Aesthet Surg. 2018;71:1462–1468.
11. Kim T, Han J, Lee Y. Onlay rib bone graft in elevation of reconstructed auricle: 17 years of experience. Arch Plast Surg. 2013;40:209–213.
12. Nagata S. Modification of the stages in total reconstruction of the auricle: Part I. Grafting the three-dimensional costal cartilage framework for lobule-type microtia. Plast Reconstr Surg. 1994;93:221–230; discussion 267–268.
13. Nagata S. Modification of the stages in total reconstruction of the auricle: Part II. Grafting the three-dimensional costal cartilage framework for concha-type microtia. Plast Reconstr Surg. 1994;93:231–242; discussion 267–268.
14. Nagata S. Modification of the stages in total reconstruction of the auricle: Part III. Grafting the three-dimensional costal cartilage framework for small concha-type microtia. Plast Reconstr Surg. 1994;93:243–253; discussion 267–268.
15. Breugem CC, Stewart KJ, Kon M. International trends in the treatment of microtia. J Craniofac Surg. 2011;22:1367–1369.
16. Park JY, Park C. Microtia reconstruction in hemifacial microsomia patients: Three framework coverage techniques. Plast Reconstr Surg. 2018;142:1558–1570.
17. Klockars T, Rautio J. Embryology and epidemiology of microtia. Facial Plast Surg. 2009;25:145–148.
18. Bennun RD, Mulliken JB, Kaban LB, Murray JE. Microtia: A microform of hemifacial microsomia. Plast Reconstr Surg. 1985;76:859–865.
19. Yamada A, Ueda K, Yorozuya-Shibazaki R. External ear reconstruction in hemifacial microsomia. J Craniofac Surg. 2009;20(Suppl 2):1787–1793.
20. Billings KR, Qureshi H, Gouveia C, Ittner C, Hoff SR. Management of hearing loss and the normal ear in cases of unilateral microtia with aural atresia. Laryngoscope 2016;126:1470–1474.
21. Suutarla S, Rautio J, Ritvanen A, Ala-Mello S, Jero J, Klockars T. Microtia in Finland: Comparison of characteristics in different populations. Int J Pediatr Otorhinolaryngol. 2007;71:1211–1217.
22. Cho BC, Lee SH. Surgical results of two-stage reconstruction of the auricle in congenital microtia using an autogenous costal cartilage alone or combined with canaloplasty. Plast Reconstr Surg. 2006;117:936–947.
23. Chang SO, Lee JH, Choi BY, Song JJ. Long term results of postoperative canal stenosis in congenital aural atresia surgery. Acta Otolaryngol Suppl. 2007;558:15–21.
24. Speltz ML, Wallace ER, Collett BR, Heike CL, Luquetti DV, Werler MM. Intelligence and academic achievement of adolescents with craniofacial microsomia. Plast Reconstr Surg. 2017;140:571–580.
25. Wang X, Feng S, Tang X, et al. Incidents of mandibular distraction osteogenesis for hemifacial microsomia. Plast Reconstr Surg. 2018;142:1002–1008.
26. Moon IY, Oh KS, Lim SY, Pyon JK, Mun GH, Bang SI. Estimation of eighth costal cartilage in surgical timing of microtia reconstruction. J Craniofac Surg. 2015;26:48–51.
27. Lee KT, Oh KS. Predictors for unfavorable projection of the constructed auricle following ear elevation surgery in microtia reconstruction. Plast Reconstr Surg. 2018;141:993–1001.
28. Fukuda O, Yamada A. Reconstruction of the microtic ear with autogenous cartilage. Clin Plast Surg. 1978;5:351–366.
29. Jing C, Hong-Xing Z. Partial necrosis of expanding postauricular flaps during auricle reconstruction: Risk factors and effective management. Plast Reconstr Surg. 2007;119:1759–1766.
30. Frenzel H, Wollenberg B, Steffen A, Nitsch SM. In vivo perfusion analysis of normal and dysplastic ears and its implication on total auricular reconstruction. J Plast Reconstr Aesthet Surg. 2008;61(Suppl 1):S21–S28.
31. Wang WS, Yan DM, Chen JY, Zhang D, Shao Y, Peng WH. Clinical efficacy of a modified Nagata method that retains the fascia pedicle of the mastoid skin flap in auricular reconstruction of Chinese microtia patients. Plast Reconstr Surg. 2016;137:977–979.
32. Bauer BS. Reconstruction of the microtic ear. J Pediatr Surg. 1984;19:440–445.
33. Janis JE, Harrison B. Wound healing: Part I. Basic science. Plast Reconstr Surg. 2016;138:9S–17S.
34. Yeakley JW, Jahrsdoerfer RA. CT evaluation of congenital aural atresia: What the radiologist and surgeon need to know. J Comput Assist Tomogr. 1996;20:724–731.
35. Ahn J, Ryu G, Kang M, Cho YS. Long-term hearing outcome of canaloplasty with partial ossicular replacement in congenital aural atresia. Otol Neurotol. 2018;39:602–608.
36. Ishikura N, Kawakami S, Yoshida J, Shimada K. Vascular supply of the subcutaneous pedicle of Nagata’s method in microtia reconstruction. Br J Plast Surg. 2004;57:780–784.
37. Park C, Lineaweaver WC, Rumly TO, Buncke HJ. Arterial supply of the anterior ear. Plast Reconstr Surg. 1992;90:38–44.
Copyright © 2020 by the American Society of Plastic Surgeons