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

• Grant number: 15/25095-0
• Support Opportunities: Regular Research Grants
• Start date: April 01, 2016
• End date: February 28, 2018
• 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: Carina Yuri Fussuma ; Helena Hotz Arroyo ; Thais Mauad

Abstract

Diode laser has excellent hemostatic properties, as a result of better absorption by melanin and hemoglobin less than water. These characteristics lead to incision and coagulation with minimal necrosis. Compared with the most commonly used lasers in larynx pathologies - CO2 and Nd: YAG - the diode laser is more lightweight and portable, has long durability and is relatively inexpensive. The diode laser could be successfully used in phonosurgery in order to achieve minimally invasive procedures, time saving and low cost. However, the scar reaction to the use of different parameters of this instrument, although impact on postoperative voice quality, is still unknown. Studies about the healing after using this tool is important, hence the vocal fold scarring is a significant factor of dysphonia following phonosurgery. Objective: The aim of this study is to compare the healing of rabbit vocal fold after incisions using 980 nm wavelength diode laser between different parameters (power, frequency, mode). Material and Methods: Experimental study - 21 New Zealand white adult rabbits will undergo the laryngoscopy. The laser diode is adjusted to the wavelength of 980 nm and optical fiber 400 micrometers. In each vocal fold is caused spot injury 20s into 3 groups of 7 rabbits. At group 1, different frequencies will be compared; in group 2, different power and group 3 different modes of energy. The rabbits will be sacrificed a week after surgery. Histological sections stained by HE will be evaluated for the integrity of the epithelium, lesion length in depth, degree of inflammation, vertical and horizontal extent of the injury. Concentration of eosinophils will be evaluated by Congo-Red staining, while concentration and organization of elastic fibers through Resorcin-Fucsin staining. Finally, concentration and collagen organization will be evaluated by immunohistochemistry. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ARROYO-RAMOS, HELENA HOTZ; NERI, LARISSA; MANCINI, MARILIA WELLICHAN; DUARTE NETO, AMARO NUNES; MAUAD, THAIS; IMAMURA, RUI. Effects of diode laser setting for laryngeal surgery in a rabbit model. EUROPEAN ARCHIVES OF OTO-RHINO-LARYNGOLOGY, v. 276, n. 5, p. 1431-1438, MAY 2019. (15/25095-0)