Submucosal injection of micronized acellular dermal matrix: analysis of biocompatibility and durability.

BACKGROUND Posterior pharyngeal augmentation is a recognized treatment for velopharyngeal insufficiency in selected candidates. To date, however, the procedure has failed to gain widespread acceptance because of the absence of an implant material with sufficient safety, durability, and biocompatibility. In this study, the use of micronized acellular dermal matrix injection for augmentation of the posterior pharynx was investigated. Using a porcine animal model, the safety and durability of posterior pharyngeal augmentation by micronized decellularized dermis was evaluated. METHODS Twelve Yorkshire piglets were used in this study. Under general anesthesia, porcine-derived micronized acellular dermal matrix was injected into the submucosa of the right side of the pharynx. At 30 days, the animals were euthanized, and the implants and surrounding tissues were assessed grossly for degree of augmentation and histologically to determine the extent of host cell infiltration, vascularization, and matrix deposition and remodeling. RESULTS No animal perioperative or postoperative morbidity resulted from the operations. When the animals were euthanized and the tissue was harvested at 30 days, there existed no evidence of gross augmentation on the experimental side of the pharynx in any of the specimens. Histologic analysis demonstrated trace amounts of residual implant, with extensive host lymphocytic infiltration of the material. CONCLUSIONS Although micronized acellular dermal matrix is a safe material when injected into the pharyngeal wall, this study demonstrated that it is not a durable implant at this site. The authors do not recommend its use for long-term soft-tissue augmentation of the posterior pharyngeal wall in patients with velopharyngeal insufficiency.