Vocal Fold Epithelium Research Articles

Células de Langerhans no epitélio da prega vocal humana: estudo imunoistoquímico

Células de Langerhans (CL) são um tipo de células dendríticas que têm funções que envolvem apresentação de antígeno e a estimulação de resposta T dependente. Elas representam aproximadamente 4% das células do epitélio laríngeo. OBJETIVO: Identificar a presença de CL no epitélio das pregas vocais, comparar suas subpopulações, bem com comparar a capacidade de quatro marcadores imunoistoquímicos. FORMA DE ESTUDO: Experimental. CASUÍSTICA E MÉTODO: Seis cadáveres, 3 homens e 3 mulheres foram estudados. Foram analisadas amostras de pele e das pregas vocais coradas e imunomarcadas para vimentina, proteína S-100, CD-68 e fascina. Após análise histológica, foi realizado o teste t de Student e análise de variância no estudo estatístico. RESULTADOS E CONCLUSÕES: Foi possível identificar a presença de CL no epitélio das pregas vocais de humanos não fumantes de ambos os sexos. A fascina, a vimentina o CD-68 mostraram-se bons marcadores das CL, enquanto a proteína S-100 teve estatisticamente menor poder de marcação tanto na prega vocal (p=0,01) como na pele (p=0,02). Foi possível identificar três diferentes subpopulações de CL presentes tanto na prega vocal como na pele destes indivíduos, contudo apenas na pele observarmos maior quantidade estatisticamente significante na camada basal do epitélio.

Phonomicrosurgery for benign vocal Fold lesions - our experience

Benign lesions of glottis creates stiffness of the vocal fold and inefficient glottal valve, aerodynamically effecting the vocal quality by preventing smooth vocal edge closure. Introduction of phonomicrosurgical techniques based on Hirano 's principle of vocal fold epithelium have revolutionized results of voice surgery. Our experience in the management of benign vocal fold lesions by phonomicrosurgical techniques with pre and post operative stroboscopic, perceptual and computerized acoustic voice analysis is described.

Cell biology of laryngeal epithelial defenses in health and disease: further studies.

This is the second annual report of an international collaborative research group that is examining the cellular impact of laryngopharyngeal reflux (LPR) on laryngeal epithelium. The results of clinical and experimental studies are presented. Carbonic anhydrase (CA), E-cadherin, and MUC gene expression were analyzed in patients with LPR, in controls, and in an in vitro model. In patients with LPR, we found decreased levels of CAIII in vocal fold epithelium and increased levels in posterior commissure epithelium. The experimental studies confirm that laryngeal CAIII is depleted in response to reflux. Also, cell damage does occur well above pH 4.0. In addition, E-cadherin (transmembrane cell surface molecules, which have a key function in epithelial cell adhesion) was not present in 37% of the LPR laryngeal specimens. In conclusion, the laryngeal epithelium lacks defenses comparable to those in esophageal epithelium, and these differences may contribute to the increased susceptibility of laryngeal epithelium to reflux-related injury.

Accuracy of Histological Examination following Endoscopic CO2 Laser-Assisted Laryngectomy

We reviewed 242 cordectomy or supraglottic laryngectomy cases operated since 1989. The vocal fold epithelium removed during subepithelial cordectomy with diagnostic intent or biopsies of the operative site after tumor resection underwent frozen section examination. However, the surgical specimen never underwent frozen section analysis. Conventionally, the histopathologist examined the margin area free of laser coagulation. Using the Acuspot micromanipulator alone, coagulation depth was less than or equal to 100 µm; with the Acublade, it was less then 20 µm. Of 181 frozen sections, 154 (85.1%) had negative margins, 23 (12.7%) had positive margins and 1 (0.6%) had moderate dysplasia of the section margin. Reading was inconclusive in 2 cases (1.1%) and impossible in 1 (0.6%). The second examination of the margins during examination of the surgical specimen did not reveal false-positive or false-negative results. Of the 23 patients with positive resection margins at frozen section analysis, 8 (34.8%) underwent immediate and more extensive cordectomy. Frozen section analysis is reliable and cost-effective in oncology for endoscopic partial laryngectomy.

Regulation of vocal fold transepithelial water fluxes.

Vocal fold hydration is critical to phonation. We hypothesized that the vocal fold generates bidirectional water fluxes, which are regulated by activity of the Na(+)-K(+)- ATPase. Western blots and immunohistochemistry demonstrated the presence of the alpha-subunit Na(+)-K(+)-ATPase in the canine vocal fold (n = 11). Luminal cells, basal and adjacent one to two layers of suprabasal cells within stratified squamous epithelium, were immunopositive, as well as basolateral membranes of submucosal seromucous glands underlying transitional epithelia. Canine (n = 6) and ovine (n = 14) vocal fold mucosae exhibited transepithelial potential differences of 8.1 +/- 2.8 and 9.3 +/- 1.3 mV (lumen negative), respectively. The potential difference and short-circuit current (ovine = 31 +/- 4 microA/cm(2); canine = 41 +/- 10 microA/cm(2)) were substantially reduced by luminal administration of 75 microM acetylstrophanthidin (P < 0.05). Ovine (n = 7) transepithelial water fluxes decreased from 5.1 +/- 0.3 to 4.3 +/- 0.3 microl x min(-1) x cm(-2) from the basal to luminal chamber and from 5.2 +/- 0.2 to 3.9 +/- 0.3 microl x min(-1) x cm(-2) from the luminal to basal chamber by luminal acetylstrophanthidin (P < 0.05). The presence of the Na(+)-K(+)-ATPase in the vocal fold epithelium and the electrolyte transport derived from its activity provide the intrinsic mechanisms to regulate cell volume as well as vocal fold hydration.

Phonomicrosurgical management of vocal fold polyps: The subepithelial microflap resection technique

Vocal fold polyps are typically caused by acute and chronic trauma to the microvasculature of the superficial lamina propria (SLP). Shearing stresses that are induced by hyperfunctional glottal sound production lead to bleeding into the SLP and malformed neo-vascularized masses. Because the primary process does not involve the epithelium, the authors designed a technique to resect hemorrhagic polyps by epithelial cordotomy with partial or complete preservation of the vocal fold epithelium. This approach is different from the traditional microsurgical resection of hemorrhagic polyps by amputation with or without the carbon dioxide laser. Forty patients who underwent microlaryngoscopic resection of hemorrhagic polyps from 1996 through 1998 were reviewed retrospectively. Thirty-six of the 40 procedures were by epithelial cordotomy and subepithelial removal of the polyp contents. Sixteen of 36 were assisted by a subepithelial infusion of saline and epinephrine, and all were 3 mm to 6 mm. Four of 40 polyps were amputated; all of these were less than 3 mm and were pedicled on a narrow base. Cold instruments were used exclusively in all 40 patients. Postoperative laryngeal stroboscopy within 2 weeks revealed improved mucosal wave propagation and improved glottal closure in all 33 patients in whom postoperative strobovideolaryngoscopy was available. The epithelial cordotomy technique was introduced to minimize disturbance of normal SLP and epithelium. Despite the hemorrhagic nature of these lesions, cold instruments could be used exclusively with facility due to careful microdissection between the polyp and the residual normal SLP and the enhanced hemostasis provided by the subepithelial infusion of saline and epinephrine. The rapid return to improved glottal function is the result of this ultra tissue-sparing technique.

Voice and healing after vocal fold epithelium removal by CO 2 laser vs. microlaryngeal stripping

Controversy exists regarding voice recovery after the use of laser vs. microforceps techniques in the removal of benign vocal fold lesions. The purpose of this study is to compare recovery of voice and healing between groups of cats undergoing vocal fold epithelium removal by CO 2 laser and those having vocal fold stripping. Fourteen adult female cats underwent standardized unilateral vocal fold injuries by CO 2 laser ablation or stripping. After a 6-week recovery period, phonations were evoked by electrical stimulation of the midbrain periaqueductal gray area. Phonations were recorded for acoustic analysis. The larynges were harvested, fixed, and sectioned for histologic correlation. Acoustic analysis showed the mean signal-to-noise ratios in the laser group (19.72) to be significantly higher than those in the stripped group (13.51) ( p = 0.04). The stripped group showed significantly greater amplitude perturbation (8.68% vs. 2.43%, p = 0.02). No between-group difference was found for period perturbation. Histologically, the laser group showed minimal Reinke's space scarring and near-normal epithelial regeneration, and the stripped group showed marked subepithelial scarring, often involving the vocalis muscle. These results demonstrate superior recovery of voice and healing in animals undergoing vocal fold epithelium removal with the CO 2 laser. Inferior outcomes seen in the stripped group may be related to difficulty in preserving Reinke's space during epithelium removal. (Otolaryngol Head Neck Surg 1996;115:352-9.)

Vocal Fold Submucosal Infusion Technique in Phonomicrosurgery

Phonomicrosurgery is optimized by maximally preserving the vocal fold's layered microstructure (laminae propriae). The technique of submucosal infusion of saline and epinephrine into the superficial lamina propria (SLP) was examined to delineate how, when, and why it was helpful toward this surgical goal. A retrospective review revealed that the submucosal infusion technique was used to enhance the surgery in 75 of 152 vocal fold procedures that were performed over the last 2 years. The vocal fold epithelium was noted to be adherent to the vocal ligament in 29 of the 75 cases: 19 from previous surgical scarring, 4 from cancer, 3 from sulcus vocalis, 2 from chronic hemorrhage, and 1 from radiotherapy. The submucosal infusion technique was most helpful when the vocal fold epithelium required resection and/or when extensive dissection in the SLP was necessary. The infusion enhanced the surgery by vasoconstriction of the microvasculature in the SLP, which improved visualization during cold-instrument tangential dissection. Improved visualization facilitated maximal preservation of the SLP, which is necessary for optimal pliability of the overlying epithelium. The infusion also improved the placement of incisions at the perimeter of benign, premalignant, and malignant lesions, and thereby helped preserve epithelium uninvolved by the disorder.

Premalignant epithelium and microinvasive cancer of the vocal fold: The evolution of phonomicrosurgical management

Phonomicrosurgical treatment of premalignant vocal fold epithelium and microinvasive cancer combines principles of surgical oncology with advanced laryngoscopic microsurgical-techniques. This treatment is guided by mucosal-wave theory of voice production and strives not only to cure the disease but also to achieve optimal vocal function. Surgical techniques developed during the past two centuries have improved methods for vocal fold visualization, tissue retrieval, and tissue evaluation. Examination of the evolution of these surgical techniques reveals the incomplete convergence of laryngoscopic surgical theory with both the concept of premalignancy and the anatomical-physiological principles of voice production. This historical review, which helps to explain the lack of consensus about current treatment options, led to a series of four investigations. They were conducted with the aim of developing a laryngoscopic (phonomicrosurgical) management approach for improving the treatment of premalignant and microinvasive vocal fold epithelium. In the first of four investigations, 42 patients (each of whom had a significant smoking history) underwent microlaryngoscopic biopsy of 52 vocal fold lesions. These lesions, which were suspicious for atypia or malignancy and were confined to the musculomembranous vocal fold, were mapped according to surface involvement and depth of penetration. Review of the maps revealed that 27 of the 52 lesions involved only the superior/ventricular surface. For these patients, the entire layered vocal fold structure could potentially be preserved on the medial/vocalizing surface. Twenty-five of the 52 lesions involved both the superior/ventricular surface and the medial/vocalizing surface. No lesion involved only the medial surface. These data suggest that (in smokers) geographic localization of keratotic and erythroplastic lesions on the superior/ventricular surface of the musculomembranous vocal fold are likely to contain atypia. This characteristic facilitates the appropriate selection of patients for biopsy and may spare individuals, who have lesions resulting from hyperfunctional dysphonia and/or gastroesophageal reflux, from unnecessary biopsy. These two disorders typically result in pathology on the medial and/or posterior glottal surfaces. In order to determine whether a directed biopsy or an excisional biopsy approach is preferable for obtaining an accurate diagnosis, all specimens underwent whole-mount sectioning for three-dimensional histopathological analysis. Keratosis was noted: without atypia in 14; with atypia in 27; and with carcinoma in 11. The severity of the atypia usually varied throughout each specimen. The surface appearance of the lesion was not a reliable prognosticator of the severity of dysplasia either between patients or in different areas of the same lesion; therefore, excisional biopsy and whole-mount, multiple-section histopathological analysis were necessary for obtaining an accurate diagnosis.(ABSTRACT TRUNCATED AT 400 WORDS)

声帯嚢胞の臨床統計

Seventy-five patients with vocal fold cyst who visited our clinic between 1981 and 1990were studied. Almost half of the cases were male and 83% were between thirty and seventy years of age. Only two cases were younger than twenty years of age. Surgery was performed for 38 patients and 97% of those patients showed vocal improvement after surgery. Vocal function tests and acoustic analyses revealed significant improvements after surgery. There was no difference in results between the complete removal of the cyst with preservation of vocal fold epithelium and removal of the superficial cyst wall covered by vocal fold epithelium. Recurrence occurred in only one case after surgery.