Quantitative Analysis on Cartilage Growth Between Ipsilateral and Contralateral Donor Sites in Microtia Patients

Costal cartilage harvest is required in patients with unilateral microtia when autologous reconstruction is being considered. However, whether an ipsilateral or contralateral donor site should be used remains controversial. This is the first study to compare cartilaginous growth between ipsilateral and contralateral donor sites in patients with unilateral microtia.

In this retrospective study of 58 patients, the lengths of the sixth to ninth costal cartilages and 3 position-defining measurements with respect to the sixth to ninth costochondral junctions were calculated using 3-dimensional costal cartilage imaging. Patients were divided into subgroups, and the lateral differences between isolated microtia and hemifacial microsomia and between the growing and adult age groups, were compared.

In the isolated group, the sixth and seventh costal cartilages were longer on the contralateral side. The transverse dimension on the contralateral side, with respect to the sixth and seventh costochondral junctions, was also larger than that on the ipsilateral side in growing patients. However, no significant difference was observed between the 2 sides in the hemifacial microsomia group; there was also no difference between the age-related groups in this regard (P > 0.05).

These findings suggest that age- and side-related differences in donor sites should be considered in patients with isolated microtia.