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.