Evaluation of the Grafted Fascia in the Vocal Fold of Dogs: A Histologic Study.
BACKGROUND
There is no consensus on the ideal graft for medialization surgery of the vocal folds in the literature. One of the most favorable proposals is the use of autologous fascia, which seems limited by the lack of information regarding the integration of grafted tissue. Our study aims to evaluate the degree of fully engrafted fascia integration in the vocal fold lamina propria of dogs.


METHODS
Fourteen adult mongrel dogs that underwent intravenous general anesthesia were selected and kept under spontaneous ventilation. A fascia lata fragment of 4 cm2was obtained from the right leg of each dog. The dogs underwent laryngoscopy; a 3 mm incision was made in the vocal process, next to the vestibular process, and the fascia was grafted into the right vocal fold. The left vocal fold was used as a control. The animals were divided into two groups: group A, evaluated after 2 months of the procedure, and group B, evaluated after 6 months of the procedure. Histologic analysis was made semiquantitatively regarding the presence of inflammatory reaction, fibrosis, and neovascularization.


RESULTS
Our final studied group comprised 12 dogs. Microscopic examination of the larynx revealed the absence of any detectable inflammation in the incision site. The lamina propria of the grafted vocal fold showed identifiable compact, thick, and eosinophilic collagen bands. The surrounding tissue showed thin collagen bands with some organization, similar to the contralateral vocal fold.


CONCLUSIONS
The grafted fascia integrates into the vocal fold lamina propria and seems not to cause inflammatory reaction response.
Department of Otorhinolaryngology, Head and Neck Surgery, University of Campinas, UNICAMP, Campinas, São Paulo, Brazil.
Eduardo G B
EGB
Carvalho
Department of Otorhinolaryngology, Head and Neck Surgery, University of Campinas, UNICAMP, Campinas, São Paulo, Brazil. Electronic address: h_pauna@hotmail.com.
Henrique F
HF
Pauna
Department of Otorhinolaryngology, Head and Neck Surgery, University of Campinas, UNICAMP, Campinas, São Paulo, Brazil.
Almiro J
AJ
Machado
Department of Otorhinolaryngology, Head and Neck Surgery, University of Campinas, UNICAMP, Campinas, São Paulo, Brazil.
Ester M D
EMD
Nicola
Department of Pathology, University of Campinas, UNICAMP, Campinas, São Paulo, Brazil.
Albina M A M
AMAM
Altemani
Department of Otorhinolaryngology, Head and Neck Surgery, University of Campinas, UNICAMP, Campinas, São Paulo, Brazil.
Agrício N
AN
Crespo
D000818:Animals; D064592:Autografts; D003094:Collagen / Q000378:metabolism; D004285:Dogs; D005206:Fascia Lata / Q000378:metabolism / Q000473:pathology / Q000637:transplantation*; D005260:Female; D005355:Fibrosis; D006085:Graft Survival; D007249:Inflammation / Q000209:etiology / Q000473:pathology; D008297:Male; D023421:Models, Animal; D018919:Neovascularization, Physiologic; D013997:Time Factors; D014182:Transplantation, Autologous; D014827:Vocal Cords / Q000378:metabolism / Q000473:pathology / Q000601:surgery*
D003094:Collagen
Animal model; Fascia lata; Inflammatory reaction; Vocal fold grafting; Vocal folds