The aim of this study is to evaluate the differences between forward-firing and multidirectional lasers and to evaluate the effects of exposure times and power on laser ablation of thyroid tissue. This is an experimental, ex vivo study. The experiments were conducted on 3 thyroid glands using 2 power levels (3 and 5 W) and exposure times (3 and 5 minutes) with forward-firing and multidirectional lasers. The length and width of the demarcated zone were measured to assess the size of thermal effect. NADPH staining was performed to determine tissue viability. Thermal transformation caused by the forward-firing laser produced oval necrotic zones, whereas thermal transformation caused by the multidirectional-firing laser produced clear round necrotic zones, which clearly demarcated in both hematoxylin and eosin staining and NADH staining.
Keywords: forward-firing fiber; laser ablation; multidirectional fiber; thyroid gland.