Porcine Mesothelium-Wrapped Diced Cartilage Grafts for Nasal Reconstruction

Background: Fascia-wrapped diced cartilage grafts have become a useful tool in modern rhinoplasty surgery. Unfortunately, fascial harvest is associated with donor site morbidity; therefore, a nonautologous alternative to fascia would be ideal. Decellularized porcine mesothelium (PM), Meso BioMatrix, is an acellular scaffold that could potentially fill this need. To determine if PM could serve as an acceptable alternative, we histologically compared diced cartilage grafts wrapped in fascia versus PM. Methods: Human rib cartilage and temporoparietal fascia were obtained under an IRB-approved protocol. Cartilage was diced into 0.5mm pieces and implanted in subcutaneous pockets in nude rats. Implanted materials included cartilage alone, cartilage wrapped in fascia, cartilage wrapped in PM, fascia alone, or PM alone. Specimens were harvested at 8 weeks and stained with hematoxylin and eosin, Masson's trichrome, Safranin-O, and Verhoeff's stain to assess cartilage viability, architecture, and regenerative potential. Results: Unwrapped diced cartilage showed the highest cartilage viability, but was associated with loss of contour and dispersion of the cartilage pieces. Meso BioMatrix-wrapped grafts maintained contour and cartilage pieces had not dispersed; however, there was a significantly lower number of nucleated lacunae and a greater amount of basophilia than both fascia-wrapped cartilage and unwrapped cartilage. There was no significant difference in cartilage resorption between fascia-wrapped cartilage and Meso BioMatrix-wrapped cartilage or in the proteoglycan or collagen content between all groups. Conclusion: Off-the-shelf decellularized PM was associated with lower cartilage viability than unprocessed fascial allograft. No cartilage piece dispersion, fibrosis, resorption, or a foreign body reaction to Meso BioMatrix was observed. PM, although not equivalent to autologous tissue, may be utilized to achieve acceptable clinical results and be a viable alternative that limits donor side morbidity. This experimental study supports further clinical investigation of this material in rhinoplasty procedures.