Histological and Biomechanical Considerations of Donor Costal Cartilage Allografts for Total Ear Reconstruction

ObjectiveDonor costal cartilage (DCC) allografts for microtia reconstruction have shown promising clinical results, but characterization of the allografts' intrinsic properties has yet to be performed.DesignHistologically, DCC allografts were compared to autologous costal cartilage (ACC). Biomechanical properties of eight DCC were compared with normative literature values.SettingUniversity laboratory.Patients, ParticipantsAdolescent and teenage patients undergoing microtia/anotia reconstruction.Main Outcome MeasuresHistological comparisons between DCC and ACC were performed using Safranin O, Alcian Blue, Masson's Trichrome, and Collagen II-specific staining. Biomechanical evaluation of DCC yielded Young's modulus, ultimate tensile strength, and ultimate compressive strength.ResultsHistologic analysis demonstrated preservation of most collagen content, with a notable reduction in the glycosaminoglycan content of the extracellular matrix in DCC. DCC demonstrated biomechanical performance that overlaps with ACC based on reported literature values.ConclusionsThe histologic integrity and biomechanical characteristics reveal DCC may have structural integrity that resembles ACC.