Abstract: A negative pressure suction sheath includes a sheath, a negative pressure joint, and a dilator; the negative pressure joint includes a main channel cavity and a negative pressure suction channel cavity located at one side of the main channel cavity, a proximal end of the sheath is connected to a distal end of the main channel cavity, the dilator is inserted from a proximal end of the main channel cavity and extends out of a distal end of the sheath, and is detachably connected to the main channel cavity; the main channel cavity is provided with a side channel port, the negative pressure suction channel cavity is communicated with the side channel port; a cavity wall of the main channel cavity is provided with a pressure regulating port. Therefore, an operator only needs to adjust the size of the pressure regulating port to adjust the negative pressure.

Abstract: A sheath includes: a ring-shaped inner layer structure, a ring-shaped outer layer structure and a frame structure, which can be radially expanded with the inflation of a balloon inside the inner layer structure. When the inner layer structure, the frame structure and the outer layer structure are not radially expanded, a radial dimension of an inner channel of the inner layer structure is at a first radial dimension, and the first radial dimension is greater than or equal to a radial dimension of the balloon that is not inflated. After the inner layer structure, the frame structure, and the outer layer structure are radially expanded, and the balloon is removed or deflated, the radial dimension of the inner channel of the inner layer structure is at a second radial dimension, and the second radial dimension is greater than the first radial dimension.

Abstract: A sheath includes: a ring-shaped inner layer structure, a ring-shaped outer layer structure and a frame structure, which can be radially expanded with the inflation of a balloon inside the inner layer structure. When the inner layer structure, the frame structure and the outer layer structure are not radially expanded, a radial dimension of an inner channel of the inner layer structure is at a first radial dimension, and the first radial dimension is greater than or equal to a radial dimension of the balloon that is not inflated. After the inner layer structure, the frame structure, and the outer layer structure are radially expanded, and the balloon is removed or deflated, the radial dimension of the inner channel of the inner layer structure is at a second radial dimension, and the second radial dimension is greater than the first radial dimension.