Histologic Evaluation of Micronized AlloDerm After Injection Laryngoplasty in a Rabbit Model

Abstract

NA Laryngoscope, 127:E166-E169, 2017.

Histone Variants as Stem Cell Biomarkers for Long‐Term Injection Medialization Laryngoplasty

“…In previous work, we tested the efficacy of a MACD+ADSCs bioreagent for promoting VF medialization post RLN sectioning. We noted that compared to MACD alone, a medialization promoting volume three times larger was observed in the MACD+ADSC group at 12 weeks postinjection . Here, we focus on protein biomarkers of ADSC proliferation associated with the increased ellipsoid volume that correlate with the duration of clinical benefit.…”

“…To distinguish exogenous from endogenous cells, injected stem cells have been labeled, but dyes and biologicals are rapidly extruded and the signal fades within days. We previously showed that a combination of micronized acellular dermis (MACD) and adipose mesenchymal stem cells (ADSCs) increased long‐term IML medialization volume . We hypothesized that continued in vivo proliferation of ADSCs was mostly responsible for these results, but inflammatory processes may have also played a part.…”

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

“…These revealed significant differences in volume retention between groups. For group 1, the mean volume at 4 weeks postlaryngoplasty was 341 ± 89 mm 3 , and at 12 weeks the mean volume was 62 ± 62 mm 3 , a difference of 81% in mean volumes ( P = .02) . In contrast, in the group that received undifferentiated ADSCs (group 2), there was no significant difference in volumes after 4 weeks compared to 12 weeks, with mean volumes of 295 ± 102 mm 3 and 235 ± 35 mm 3 , respectively ( P = .38).…”

“…The size of deposited material at each time point was estimated as previously described . Briefly, the volume of injection was approximated to an ellipse with the formula V = 4/3*π*( L /2* W /2* H /2), where L = length, W = width, and H = height.…”

“…W and L corresponded to the maximal axial dimensions of the stained material, whereas H was determined from the number of 5‐μm sections necessary to completely evaluate the stained area. As described previously, when making histologic measurements, the maximal dimensions were measured to the border of the injected area including the inflammatory infiltrate, as this represents the clinical bulk of the material . This is a similar method to previous studies on subdermal injection of micronized AlloDerm, when they used dimensions taken from clinical photographs and estimated the injected area as a cylinder, with results reported as percentage of tissue lost over time …”