Survival of diced cartilage grafts: an experimental study.

BACKGROUND: Use of diced cartilage grafts in rhinoplasty surgery has recently undergone a dramatic resurgence. Some authors recommend wrapping diced cartilage with oxidized methylcellulose (i.e., Surgicel). Others prefer wrapping diced cartilage with autogenous deep temporal fascia. This study was designed to compare the behavior of diced cartilage grafts as an isolated entity or when wrapped with either Surgicel or deep temporal fascia.

METHODS: Septal cartilage and deep temporal fascia were obtained from five patients in this institutional review board-approved study. The cartilage was diced into 0.5-mm pieces and implanted into subcutaneous dorsal skin pockets of Rowlett nude rats as isolated diced cartilage grafts, or wrapped in Surgicel or deep temporal fascia. Pieces of Surgicel and fascia were implanted alone as controls. The specimens were harvested at 8 weeks; processed by thin-section histology; stained with hematoxylin and eosin, Masson's trichrome, glial fibrillary acidic protein, safranin-O, and Evans van Gieson; and evaluated to determine cartilage viability and architectural characteristics.

RESULTS: Diced cartilage wrapped in Surgicel yielded the lowest percentage viability and minimal staining with hematoxylin and eosin, trichrome tissue, safranin-O, and Evans van Gieson stains. Diced cartilage grafts wrapped in fascia had the greatest percentage of viable cartilage. The grafts wrapped in deep temporal fascia also demonstrated the strongest staining with the aforementioned stains. Differences in uptake of glial fibrillary acidic protein were not noticeable between the three groups. However, absolute numbers of nucleated lacunae and basophilic lacunae were significantly higher for grafts wrapped in deep temporal fascia.

CONCLUSIONS: Diced cartilage grafts have reemerged as a viable method for nasal reconstruction in both primary and secondary rhinoplasty. Wrapping diced cartilage specimens contains the individual pieces and facilitates graft placement. Surgicel wraps appear to incite an inflammatory response and subsequent absorption of the cartilage. Fascia wraps appear to minimize inflammatory responses to the cartilage, thereby preserving healthy cartilage. This study demonstrates that deep temporal fascia is the preferred envelope with which to facilitate graft containment and maintain chondrocyte viability of diced cartilage grafts.