Study of vocal fold healing with 980 nm and 1470nm wavelength diode laser in a rabbit model.

• Grant number: 18/09071-1
• Support Opportunities: Regular Research Grants
• Start date: March 01, 2019
• End date: February 29, 2020
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Rui Imamura
• Grantee: Rui Imamura
• Host Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated researchers: Thais Mauad

Abstract

Introduction: Phonosurgical procedures to remove laryngeal lesions should respect the vocal fold structure (1,2). In some cases, unfavorable outcomes of laryngeal microsurgery may result from inadequate healing (3), which may be minimized with the development of new technologies and therapies for scar prevention (4-6). The diode laser is one of such technologies; when compared to the most utilized lasers for treating laryngeal lesions, it is very light and, therefore, practical to be transported, it has long durability and it is relatively cheap. However, scar reactions caused by the use of different diode laser wavelengths (980nm and 1470nm) in the vocal folds have not been studied. Objective: To compare the rabbit vocal fold healing after lesion with diode laser of 980nm and 1470nm, under pulsed or continuous exposition mode. Methods and Material: Experimental study - 20 adult rabbits (divided into four groups) will be anesthetized and submitted to direct laryngoscopy. In each vocal fold, a punctate lesion will be performed with the laser adjusted to 980nm in one of the vocal folds and to 1470nm in the other. In groups 1 and 3, the laser will be used in pulsed mode, while in groups 2 and 4, in continuous mode. The time for sacrifice will be seven days for groups 1 and 2 and 30 days for groups 3 and 4. Histological sections stained by HE will be analyzed as to the integrity of the epithelium, extent of the process and degree of inflammatory process. The concentration and organization of elastic and collagen fibers will be analyzed with Resorcin-Fuchsin staining and immunohistochemistry, respectively. (AU)