Effects of hepatocyte growth factor injection and reinjection on healing in the rabbit vocal fold.

OBJECTIVES/HYPOTHESIS: Hepatocyte growth factor (HGF) is a multifunctional polypeptide that plays various roles in embryogenesis and tissue regeneration and exhibits marked antifibrotic activity. The present study sought to assess the effects of HGF injection and reinjection coinciding with its peak of activity on collagen density, vessel density, inflammatory reaction in the lamina propria, and mean epithelial thickness in the injured rabbit vocal fold. STUDY DESIGN: Prospective, controlled, experimental animal study. METHODS: Fourteen rabbits were subdivided into two groups and underwent injury of the vocal folds. Immediately after injury, animals in group 1 received HGF injections into the right vocal fold (RVF), whereas those in group 2 received bilateral HGF injections and a single reinjection into the RVF 10 days after the first, to coincide with the peak of HGF activity. The left vocal folds (LVFs) served as controls in both groups. Histological assessment of laryngeal specimens was performed at 30 and 40 days, respectively. RESULTS: In both groups, collagen density was lower in the right (treated) vocal folds than in the left (control) folds (P=0.018). Vessel density was higher in the RVFs in group 2 (P=0.018). Differences were found in mean epithelial thickness and inflammatory reaction in the lamina propria but did not reach statistical significance. CONCLUSIONS: In the scarred rabbit vocal fold, HGF injection is associated with decreased collagen density in the lamina propria, whereas reinjection after 10 days produces decreased collagen density and higher vessel density.

Angiogenesis, fibrinogenesis and presence of synechiae after exeresis of a swine vocal fold mucosal microflap and use of topical mitomycin-C.

PURPOSE: To evaluate swine vocal fold healing in a period of 30 days after topical mitomycin-C application. METHODS: Twelve swine underwent exeresis of mucosal flaps from the free edge of the anterior third of both vocal folds with a cold instrument (laryngeal scissors). The animals were divided into two groups: EG (Experimental Group), consisting of 6 animals undergoing topical MMC application (4 mg/dL) on the operated area for 4 minutes; CG (Control Group), 6 animals undergoing topical saline solution application on the operated area for 4 minutes. After 30 days, the animals were sacrificed and the larynges were collected and examined for the presence of synechiae as well as a histological immunohistochemical assessment of immature and mature collagen deposition, number of blood vessels and myofibroblasts. RESULTS: Mature collagen deposition in the EG was 452.12 microm(2) and 1332.31 microm(2) in the CG; immature collagen deposition was 1511.73 microm(2) in the EG and 1020.61 microm(2) in the CG. The number of myofibroblasts was 1.556 in the EG and 3.583 in the CG. The number of blood vessels was 2.565 in EG and 6.917 in the CG. There were no synechiae in the two studied groups. CONCLUSIONS: There was an increase in immature collagen deposition in the experimental group when compared with the control group. There was a decrease in mature collagen deposition in the experimental group when compared with the control group. There was a decrease in the number of myofibroblasts in the experimental group when compared with the control group. A decrease in blood vessels was observed in the experimental group when compared with the control group. There was no synechia formation in either studied group.

Angiogenesis, fibrinogenesis and presence of synechiae after exeresis of a swine vocal fold mucosal microflap and use of topical mitomycin-C / Estudo da angiogênese, fibrogênese e presença de sinéquias após exérese de fragmento de mucosa de pregas vocais de suínos utilizando instrumental frio e mitomicina-C tópica

PURPOSE: To evaluate swine vocal fold healing in a period of 30 days after topical mitomycin-C application. METHODS: Twelve swine underwent exeresis of mucosal flaps from the free edge of the anterior third of both vocal folds with a cold instrument (laryngeal scissors). The animals were divided into two groups: EG (Experimental Group), consisting of 6 animals undergoing topical MMC application (4 mg/dL) on the operated area for 4 minutes; CG (Control Group), 6 animals undergoing topical saline solution application on the operated area for 4 minutes. After 30 days, the animals were sacrificed and the larynges were collected and examined for the presence of synechiae as well as a histological immunohistochemical assessment of immature and mature collagen deposition, number of blood vessels and myofibroblasts. RESULTS: Mature collagen deposition in the EG was 452.12 μm² and 1332.31μm² in the CG; immature collagen deposition was 1511.73μm² in the EG and 1020.61μm² in the CG. The number of myofibroblasts was 1.556 in the EG and 3.583 in the CG. The number of blood vessels was 2.565 in EG and 6.917 in the CG. There were no synechiae in the two studied groups. CONCLUSIONS: There was an increase in immature collagen deposition in the experimental group when compared with the control group. There was a decrease in mature collagen deposition in the experimental group when compared with the control group. There was a decrease in the number of myofibroblasts in the experimental group when compared with the control group. A decrease in blood vessels was observed in the experimental group when compared with the control group. There was no synechia formation in either studied group.

OBJETIVO: Avaliar a cicatrização de pregas vocais de suínos utilizando mitomicina-C tópica, em 30 dias. MÉTODOS: Doze suínos foram submetidos à exérese de mucosa do bordo livre do terço anterior de ambas as pregas vocais com instrumental frio (tesoura curva) e divididos em dois grupos: Grupo E (GE), composto por seis animais com utilização tópica de mitomicina-C(4 mg/dL) na área cruenta por quatro minutos e Grupo Controle (GC), composto por seis animais com utilização tópica de soro fisiológico na área cruenta por quatro minutos. Após 30 dias os animais foram sacrificados e coletadas amostras das pregas vocais para avaliação de sinéquias e análise histológica com quantificação da deposição de colágeno maduro e imaturo, quantificação do número de vasos sanguíneos e miofibroblastos, por método imunoistoquímico. RESULTADOS: A deposição do colágeno maduro no GE foi de 452,12 μm² e 1332,31μm² no GC. A do colágeno imaturo foi de 1511,73μm² no GE e de 1020,61μm² no GC. O número de miofibroblastos foi de 1,556 no GE e de 3,583 no GC. O número de vasos sanguíneos foi de 2,565 no GE e de 6,917 no GC. Não houve formação de sinéquias nos grupo s estudados. CONCLUSÕES: No grupo experimento, quando comparado ao controle, houve significativamente aumento da deposição do colágeno imaturo e diminuição da deposição do colágeno maduro, do número de miofibroblastos e de vasos sanguíneos. Não houve formação de sinéquias em ambos os grupos.

Blood vessels of vocal folds: a videolaryngoscopic study.

OBJECTIVE: To analyze and compare the incidence and visual characteristics of blood vessels on the superior surface of vocal folds with polyps, nodules, and minimal structural alterations (ie, sulci, cysts, and mucosal bridges). DESIGN: Cross-sectional study. SETTING: Academic research. PATIENTS: A total of 280 videolaryngoscopic images were randomly selected and classified into the following 4 groups of 70 patients each: the vocal nodule (VN) group, the polyp group, the minimal structural alterations (MSA) group, and the control group. MAIN OUTCOME MEASURES: Laryngoscopic images were assessed for visible blood vessels and for the orientation and characteristics of the vessels. Isolated ectasias with clear boundaries were excluded. RESULTS: The highest incidence of visible vessels was observed in the MSA group (91.4%), followed by the polyp (77.1%), VN (44.7%), and control (31.4%) groups. Longitudinal and transverse vessels were found more frequently in the MSA (74.3% and 37.1%) and polyp (65.7% and 22.9%) groups than in the VN (34.3% and 12.9%) and control (25.7% and 5.7%) groups. Tangled vessels were found only in the MSA group (8.6%). Abrupt changes in the caliber of the vessels and sinuous vessels were observed only in the polyp (21.4% and 5.7%) and MSA (61.4% and 27.1%) groups. CONCLUSIONS: The main differences in the incidence and characteristics of visible blood vessels occurred between 2 pairs of groups: MSA-polyp and VN-control. The incidence was significantly higher in the MSA group than in the polyp group, and the incidence in both the MSA group and the polyp group was also significantly higher than that in the VN and control groups. The greatest variations were found in the MSA group, including the presence of tangled blood vessels (which was observed only in this group).

Linfáticos da laringe / Lymphatics of the larynx

Realizamos 147 injeçöes de diferentes corantes e/ou contraste radiopaco, em 77 laringes de cäes a fim de se estudar os linfáticos da submucosa da laringe e suas eventuais vias preferencias de drenagem. Os corantess utilizados (Blue Patent V, Azul da Prússia e Tinta Nankin) e/ou contraste radiopaco (Hypaque) foram previamente injetados em regiöes topográficas selecionadas. O estudo foi realizado em cäes anestesiados ou recém-sacrificados, e em laringes extirpadas. A drenagem linfática foi também estudada em cäes submetidos a ligadura prévia de eferentes linfáticos aos linfonodos cervicais. Em laringes isoladas, o estudo dos linfáticos e suas vias de drenagem foi realizado sob lupa estereoscópica, antes e após a desidrataçäo e diafanizaçäo das peças. O autor descreve os caminhos descritos pelos linfáticos da submucosa da laringe até encontrar as vias de drenagem: via superior, via média e via inferior.