Novel "Z" Technique to Overcome Warping of Costal Cartilage

Dorsal augmentation with costal cartilage is generally used for aesthetic rhinoplasty. However, the tendency of costal cartilage to warp may jeopardize the aesthetic outcome.

The aim of this study was to describe a new "Z" technique to overcome the warping of costal cartilage after implantation and to evaluate the efficacy of this technique in vitro.

A total of 31 pairs of porcine costal cartilage grafts (40 mm × 10 mm × 5 mm) were obtained and kept in Dulbecco's Modified Eagle Medium (Sigma-Aldrich, St. Louis, MO) to maintain cell viability. Paired grafts were obtained and randomly allocated for preparation by the accordion technique and the "Z" technique. Standardized photographs (obtained immediately after operation and at 4 weeks) were used for warping analysis. Biomechanical testing was performed to measure the graft's capacity to resist deformation by an external force.

Cell viability of the grafts at 4 weeks was comparably good in the accordion group and the Z group (61.88% ± 4.47% vs 67.48% ± 7.03%, P = 0.55). Warping angle was comparable between the 2 groups (P > 0.01). The capacity to resist external force was significantly better in the Z group; the force needed to cause deformation was 3.98 ± 1.04 N in the Z group vs 1.61 ± 0.47 N in the accordion group in lateral view (P < 0.0001), and 1.33 ± 0.41 N vs 0.96 ± 0.24 N, respectively, in frontal view (P = 0.0013).

The "Z" technique appears to be a simple and effective method to minimize the tendency of costal cartilage to warp after implantation.