Using Auricular Cartilage-fascia Composite Tissue Free Grafting Technique to Improve Cartilage Survival Outcomes.

Abstract

Auricular cartilage graft has a wide range of applications in plastic and reconstructive surgery. However, there is still a risk of absorption of the grafts over time. Intrinsic postauricular fascia (IPF) with a rich vascular network may play an important role in the nutrition and repair of auricular cartilage. This study aimed to investigate the effect of IPF on the survival viability of free auricular cartilage grafts. 24 auricular cartilages were obtained from 6 New Zealand white rabbits which were divided into the cartilage-fascia composite graft group (FC group, n=12) and the cartilage without fascia group (C group, n=12). Two groups of cartilage were implanted into each side of the subcutaneous pocket of the rabbit's dorsum. The rabbits were sacrificed after 3 months and all cartilage grafts were obtained. Macroscopic observation, histopathological staining, and biomechanical testing were performed on all specimens. There were significant differences between the 2 groups regarding proliferating chondrocytes, apoptotic chondrocytes, vascularization, and matrix collagen. Compared to the auricular cartilage grafts without fascia, the auricular cartilage-fascia composite grafts had more neovascularization, proliferative chondrocytes, and type II collagen, with a homogeneous cartilage matrix and no obvious areas of heterogeneous staining. Young's modulus and ultimate tensile strength of cartilage were reduced in both groups compared to pretransplantation, but the composite graft group was superior to the fascia-free group. Auricular cartilage-fascial composite tissue free graft could improve cartilage survival outcomes with higher viability and mechanical properties.