Long-term Outcomes on Patients with Microtia after Autogenous Costal Cartilage Reconstruction

Abstract

Autologous costal cartilage grafts remain the gold standard method for microtia reconstruction. However, reports on its long-term outcomes are limited. We present two cases with >40-year outcomes after auricular reconstruction with autologous costal cartilage. A 56 year-old woman and a 53 year-old man presented to our institution with complaints of wire exposure. In both cases, the reconstructed ear was deformed. A computerized tomography scan revealed calcification of the reconstructed costal cartilage graft framework. To our knowledge, these cases present the longest outcomes (50 and 42 years for the 56 year-old woman and 53 year-old man, respectively) of microtia reconstruction using autologous cartilage grafts. We found that ear frameworks constructed from costal cartilage tended to calcify in the long term, as in the natural course of costal cartilage. Therefore, the possibility of calcification of costal cartilage grafts should be relayed to patients and parents, and lifelong surveillance after reconstruction should be recommended.

Background

Microtia is a congenital anomaly that occurs in 0.8-4.2 cases per 10,000 births¹⁾. Several reconstructive methods have been reported including autologous costal cartilage grafts, porous polyethylene implants (Medpor), and silastic frameworks. However, autologous costal cartilage graft has remained the gold standard method for >60 years since the first report by Tanzer in 1959²⁾. Although autologous costal cartilage graft has a relatively low complication rate, reports on its long-term outcomes are quite limited³⁾.

Here, we present two cases with >40-year outcomes after auricular reconstruction with autologous costal cartilage, which are, to the best of our knowledge, one of the longest outcomes of microtia reconstruction using costal cartilage graft.

Case Reports

Case 1

A 56 year-old woman presented with wire exposure and pain in the right ear. She had a history of auricular reconstruction using an autologous costal cartilage graft for microtia at age 6 years. She also had a history of wire exposure twice before this episode of wire exposure at ages 32 (Figure 1A) and 39 years. At that time, the exposed part of the wire had been resected. On examination at age 56 years, the reconstructed ear, which was originally classified as a small concha type, was severely deformed including uneven helix and blurred superior crus (Figure 1B). On palpation, the framework was hard and nodulous with a partial defect at the helix. Some parts of the reconstructed frame were absorbed spontaneously (Figure 1A, B; Points α and β). X-rays and computerized tomography (CT) showed diffuse calcification of the costal cartilage graft framework and several long fixing wires (Figure 1C, D and E). The donor-site scar was inconspicuous, and the chest wall deformity was not observed (Figure 1F). The exposed part of the wire was resected under local anesthesia. There was no evidence of wire decomposition. The bacterial culture of the wound was negative. Her postoperative course was uneventful, and no recurrence of wire exposure was observed 8 months postoperatively.

Figure 1.

A) Appearance 26 years postoperatively.

B) Appearance 50 years postoperatively.

Severe deformity including uneven helix and blurred superior crus was observed. Some parts of the graft were absorbed spontaneously (Points α and β).

C–E) Diffuse calcification of the reconstructed costal cartilage graft framework was observed.

F) Concaved deformity of the chest wall was not observed.

Case 2

A 53 year-old man presented with wire exposure. He had a history of auricular reconstruction using an autologous costal cartilage graft for microtia at age 11 years. On examination, the reconstructed ear was slightly deformed including an uneven helix and a blurred antihelix (Figure 2A). A portion of the graft was absorbed spontaneously (Figure 2A; Point α). CT showed partial calcification of the costal cartilage graft framework and several fixing wires (Figure 2B, C). The donor-site scar was inconspicuous, and no chest wall deformity was observed (Figure 2D). The exposed wire on the superior aspect of the helix (Figure 2A; Point β) was resected without anesthesia. His postoperative course was uneventful.

Figure 2.

A) Appearance 42 years postoperatively.

Slight deformity including uneven helix and blurred antihelix was observed. A portion of the graft was absorbed spontaneously (Point α). The wire was exposed on the superior aspect of the helix (Point β).

B and C) Partial calcification of the reconstructed costal cartilage graft framework was observed.

D) No chest wall deformity was observed.

Discussion

Although several methods have been developed for microtia reconstruction, autologous cartilage-staged reconstruction is the choice of 91.3% of plastic surgeons in an American Society of Plastic Surgeons survey and thus remains the gold standard for microtia reconstruction⁴⁾.

Autologous costal cartilage graft for microtia reconstruction is reported to have a relatively low complication rate. Early postoperative complications include infection, hematoma, and skin graft necrosis. However, reports on long-term complications are limited. Most reports on long-term outcomes of microtia reconstruction are based on outcomes of <10 years^3-5). Ronde et al. reported a systematic review of “long-term” follow-up, which included reports of patients with >1-19 years of follow-up after reconstruction⁶⁾. Because microtia reconstruction using autologous cartilage graft has a history of 60 years and since it was first reported in 1959 by Tanzer²⁾, our cases of 50- and 42-year outcomes are considered one of the longest outcomes to date.

Among the long-term complications, cartilage resorption, wire exposure, and scar complications were the most frequently reported. Long et al. reported that longer follow-up duration is associated with a higher incidence of late complications, such as chest wall deformity and wire exposure⁴⁾.

Our new finding is that severe calcification occurs in the costal cartilage graft as a long-term outcome, as in the natural course of costal cartilage. It is known that the costal cartilage gradually calcified depending on age and gender. In the literature, meaningful calcification was noted in men >60 years and women >30 years in Asian patients. Sunwoo et al. reported that calcification was more frequent in female patients than in male patients⁷⁾. Using ultrasonographic evaluation, Fu et al. reported that the positive calcification rate was 80% in patients >18 years of age⁸⁾. Therefore, it is reasonable to consider that the costal cartilage graft, which was transferred to the ear, may also calcify in >40 years of, specifically women.

We did not take tissues of calcified lesions in our cases; hence, histological findings were not obtained. Rejtarova et al. reported that histologically endochondral ossifications in the costochondral zone appear in the first decade and endochondral intramembranous ossifications in the reserve zone appear after the third decade⁹⁾. Especially in the reserve zone, besides calcified and hypertrophic cartilages, an increase in asbestoid fibers and a decrease in proteoglycans can be detected. It is hypothesized that this physiological change in costal cartilage occurred similarly in the transplanted framework.

Wire exposure is also a complication that could occur in the long term. In case 1, wire exposure was not observed within the first 17 years. In case 2, wire exposure was not observed at all. However, the continuous wearing of masks due to the coronavirus disease-19 pandemic may have caused friction near the ear and triggered this episode of wire exposure.

To conclude, this study presents one of the longest outcomes of microtia reconstruction using an autologous cartilage graft. Severe calcification of the transplanted costal cartilage, resultant framework deformity, and wire exposure were observed. The possibility of calcification of costal cartilage graft and resultant framework deformity in extended long-term outcomes, especially in women, should be relayed to patients and parents. Furthermore, lifelong surveillance after reconstruction should be recommended.

Author Contributions: Writing―original draft: MK, writing―review and editing: TI, resources: KK, YT, and HA, and supervision: MO. All authors have read and agreed to the published version of the manuscript.

Conflicts of Interest: There are no conflicts of interest.

Ethical Approval: The University of Tokyo granted the approval of this study from the institutional review board with approval no.: 10527-(4).

Consent to Participate: The patients provided their written informed consent to participate in this study.

Consent for Publication: The patients provided their written informed consent to publish this study.