Histomorphology of neochondrogenesis after antihelical fold creation: a comparison of three otoplasty techniques in the rabbit.

The purpose of this article is twofold: (1) to investigate the histomorphology of cartilaginous proliferation using three different otoplasty techniques and (2) to determine whether recurrence is related either to the method of otoplasty or the duration of suture fixation. Eighteen 6-week-old New Zealand white rabbits were divided into three equal groups. In each animal, a skin pocket was developed on the posterior surface of both ears; the perichondrium of the left ear was stripped off, whereas the perichondrium of the right ear was left undisturbed. Otoplasties were performed by inserting permanent mattress sutures with (Converse-Wood-Smith) or without (Mustardé) cartilaginous incisions or by scoring of the anterior cartilaginous surface of the antihelix (Stenstrom). In each group, sutures were cut at 1, 2, 4, and 6 weeks and the animals killed 1 week later. Histomorphometric analysis was performed. Perichondrial stripping stimulated cartilaginous proliferation in all groups. The antihelical fold maintained its shape best in group 3, in which the anterior perichondrium was rasped; a fibrocartilaginous cap formed over the rasped convex surface of the antihelical fold, reinforcing and stabilizing the newly created fold. Groups 1 and 2, in contrast, demonstrated significantly less anterior cartilaginous proliferation than did group 3, and cap formation was not observed. No significant differences were apparent between groups 1 and 2 in either the quantity or quality of cartilaginous proliferation in any of the time periods. Cutting the sutures at 1 week resulted in loss of shape or "flattening" of the fold in all groups; however, increased cartilaginous proliferation between 2 and 6 weeks stabilized the fold, minimizing deformability.(ABSTRACT TRUNCATED AT 250 WORDS)