Fig. 1

(A) Energy devices employed in this study: ENSEAL™ G2 Curved Tissue Sealer, HARMONIC^® HD1000i Shears, and ENSEAL™ X1 Curved Jaw Tissue Sealer (from top to bottom). (B) Six-channel model of AM-9000 K thermocouple. (C) An ex-vivo model analyzing the direct thermal effect. A pin electrode was placed into the tissue, and the temperature was recorded at 1, 3, and 5 mm away from the energy device. (D) An ex-vivo model analyzing the indirect steam thermal effect. A pin electrode was placed above the jaw grasping tissue, and the temperature of the surrounding space was recorded at six different points from the grasping site (1, 5, and 10 mm of the outside (a) and inside (b). (E) An ex-vivo model analyzing the steam thermal spread of energy devices. Versatile Training Tissue (VTT), whose color changes from brown to white at approximately 50 °C, was located horizontally (a) and vertically (b). The center of the VTT was grasped and activated once an energy device was used. (F) VTT after activation of energy device (a: horizontal sheet, b: vertical sheet). The steam spread area was calculated by the sum of the white areas of both horizontal and vertical sheets.