(301) Mastoid Obliteration and Ear Canal Reconstruction Using Decellularized Cartilage

Introduction: To improve bone regeneration after canal wall down (CWD) mastoidectomy, we evaluated the ability of the the application of decellularized cartilage in promoting osteogenesis in the treatment of postoperative temporal bone defect using an animal model.

Methods: Human nasal septal cartilages were obtained from surgical cases. The harvested cartilages were treated by the freezing and grinding technique. The obtained cartilage flakes were treated with 1% Triton X-100 or 2% sodium dodecyl sulfate (SDS) for decellularization of the cartilage flakes. 21 Sprague-Dawley rats with normal MEs were divided into three groups (n = 7 for each group): control (sham surgery), cartilage, and decellularized cartilage. Histopathologic findings and computed tomography images were obtained from each tympanic bulla at 12 weeks post-surgery, and the obliteration ratio and new bone formation were compared among groups.

Results: Compared with the sham and cartilage groups, decellularized cartilage group showed significantly higher obliteration ratios and new bone formation. Moreover, decellularized cartilage group showed new bone formation in both the periphery and central region of the tympanic bulla cavity, which indicating prominently enhanced osteogenesis compared to the sham (p = 0.01) and cartilage groups (p = 0.03). The mean area of newly formed bone at the periphery of the largest tympanic bulla in axial view were significantly larger in the decellularized cartilage group (12419.29 ± 1560.55 um2) than the cartilage group (7646.48 ± 1609.98 um2) (p = 0.00797).

Conclusions: From the results, decellularized cartilage showed accelerated osteogenesis for reconstruction of postoperative temporal bone defects. These results might provide a basis for the clinical application of decellularized cartilage in mastoid obliteration.