[Vocal fold superficial layer of lamina propria histology after the position of mucosa pediculated flap: canine experimental study]

Abstract

Many techniques were applied to treat patients with sulcus vocalis and scarred vocal folds. Their results were not good enough. In the Technique of Vocal Fold Pediculated Mucosa Flap, an anterior pediculated flap of vocal fold is positioned on the superficial layer of the lamina propria, below the free margin. Aim: To describe histological postoperative findings on the superficial layer of lamina propria during the application of the technique Vocal Fold Pediculated Mucosa Flap. The following parameters were compared between tested and control groups: total, type I and type III collagen and number of cellular nucleus. Study design: experimental. Material and Method: Fifteen dogs were used. One vocal fold was submitted to the intervention and the other was left as control. Each group of three dogs was sacrificed on 10, 30, 90, 180 and 360 days after the experimental surgery. Hematoxylin and eosin (H.E.) and Syrius Red were the staining techniques used. Results: Type I and total collagen suggested increased results in the tested group on postoperative days 90 and 180, nevertheless there was statistical significance only on postoperative day 180 (p<0.05). Type III collagen group area was less significant than the control group on postoperative day 180 (p<0.05). The number of cellular nucleus was increased on the 10th postoperative day, but decreased after the 30th day. Discussion: The findings about total and type I collagen and the amount of cellular nucleus on the superficial layer of lamina propria were similar to laryngeal postoperative studies in dogs. More complex studies would contribute with new data about the present subject.

Figure 1

Incision made on the upper surface of the vocal fold and subepithelial detachment.

Figure 2

Incision on the upper surface of the vocal fold, 2 millimeters laterally to the first incision and detachment under the region delimited by two incisions.

Figure 3

Performance of pediculated graft, positioning on subepithelial region and fixation with fibrin glue.

Figure 4

Pediculated flap placed on the submucous bed of the tested dog (postoperative day 10). Staining: Syrius Red under polarized light and HE.

Figure 5

Pediculated flap placed on the submucous bed of the tested dog (postoperative day 30). Staining: Syrius Red under polarized light and HE.

Figure 6

Pediculated flap placed on the submucous bed of the tested dog (postoperative month 12). Staining: Syrius Red under polarized light and HE.

Graph 1

Variation of mean area of total, Type I and Type III collagen in postoperative period (n=3 for each period of observation).