A stent includes a first longitudinally extended cylinder having a C-shaped cross-section and a second longitudinally extended cylinder having a C-shaped cross-section. The first cylinder includes a plurality of first longitudinal struts and an array of first radial struts extending between the first longitudinal struts. The second cylinder includes a plurality of second longitudinal struts and an array of second radial struts extending between the second longitudinal struts. The first cylinder and the second cylinder are configured to form a dense mesh structure when assembled. When assembled, the second cylinder may be disposed in the first cylinder. The first cylinder may overlap with the second cylinder to form the dense mesh structure.
