Described herein are systems and methods for securing sutures that obviate the need for tying knots. Instead of tying two ends of a suture or two sutures together with a knot, two or more suture portions can be fused or cauterized together using heat. A device can be applied to adjacent suture portions that heats the suture portions and causes the suture portions to fuse together, effectively securing the suture portions together without a knot. Such devices can include a shaft, a heating element positioned within the shaft, and a suture holder at the distal end of the shaft. The holder in an open position receives sutures and in a closed position holds the sutures. Actuation of the device causes the heating element to apply heat and fuse together sutures held by the holder. The holder can separate from the fused sutures after the sutures are fused together.