Photochemical repair of vocal fold microflap defects

Abstract

To bond vocal fold flaps using a sutureless, nonthermal laser-assisted method combining visible light and photosensitizing dyes to produce collagen crosslinks. In the ex vivo study, epithelial incisions were created in sheep vocal folds. The concentration of the Rose Bengal, and the laser fluence were varied and studied. The in vivo canine study evaluated the thickness of the basement membrane zone, density and distribution of collagen, elastin, and fibroblasts at time zero, 2 weeks, and 8 weeks. Ex Vivo: Rose Bengal at concentrations between 0.5% and 1.0% was applied to the free margins of the incision and irradiated with an Nd:YAG laser at fluences varying from 150 to 600 J/cm2 . The bonding was considered positive when the incision could withstand air at 2 pounds per square inch (psi) from a distance of 3 cm. In Vivo: 0.75% Rose Bengal was applied to the microflap edges and irradiated with an Nd:YAG laser for 140 seconds (100 J/cm2). The control side was not irradiated. Ex Vivo: Bonding was achieved with a minimum of 0.75% Rose Bengal and 300 J/cm2 . In Vivo: There was no difference in the amount of subepithelial reaction between the experimental and control sides at 8 weeks. Photochemical tissue bonding is effective at sealing vocal fold incisions and did not create long-term scarring of the vocal folds. Use of this technique may allow for more predictable healing after microflap resection and may reduce the need for postoperative voice rest.