Preliminary results of tissue‐engineered injection laryngoplasty material in a rabbit model

Objectives/Hypothesis Design and test a novel biomaterial for injection laryngoplasty aimed to increase the duration of effectiveness of micronized acellular dermis. Study Design Animal model. Methods Injection laryngoplasty was performed in three groups (n = 5) of New Zealand White rabbits. Acellular dermis was either used alone as a control (group 1), was combined with undifferentiated stem cells (group 2), or with predifferentiated chondrocytic cells (group 3). Groups 2 and 3 were supplemented with growth factors. Animals were sacrificed 4 and 12 weeks after laryngoplasty and histologic analysis was completed. The major outcome measure was volume of tissue remaining. Results After 4 weeks, the mean volume of tissue remaining was 341 ± 89 mm3, 295 ± 102 mm3, and 133 ± 15 mm3, for groups 1 to 3, respectively. At the 12‐week time point, volumes were 62 ± 62 mm3, 235 ± 35 mm3, and 107 ± 99 mm3. After 12 weeks, there was a significantly higher volume in group 2 compared to group 1 or 3 (P = .01, P = .04). Volumes between week 4 and week 12 were significantly lower in group 1 (P = .02), but not significantly different for groups 2 and 3 (P = .38, P = .74). Histologic evaluation revealed a robust lymphocytic infiltration in all cases as well as morphologic and immunophenotypic features suggestive of chondrogenic differentiation in a single animal. Conclusions Micronized acellular dermis combined with stem cells and growth factors showed significantly less resorption 12 weeks after injection laryngoplasty compared to micronized acellular dermis alone. Groups using novel tissue‐engineered biomaterial showed a lower resorption rate over time compared with acellular dermis alone. Level of Evidence NA. Laryngoscope, 128:160–167, 2018