Pieces of tissue are fused together and simultaneously cut by compressing the pieces together at an interface, delivering an impulse of electrical power which is converted into sufficient thermal energy to fuse the pieces together at the interface and simultaneously cut the fused tissue pieces along a well-defined linear path. The impulse, and the fusion and the simultaneous cutting, occur within a preferable time of 1.5-2.0 seconds but no greater than 4.0 seconds. The temperature of the thermal energy is regulated between 220° C.-320° C. The force applied on the tissue pieces is sufficient to fuse the tissue at the interface followed by further compression to cut the fused tissue along the linear path as a result of the thermal energy and a zero distance gap between jaws which compress the tissue pieces. The jaws have smooth working surfaces with an Ra of 0.15 or less microns up to 0.40 microns.