Medical stents having valves and their methods of manufacture are disclosed. The lower trigger body includes at the top a lower-and-upper body connecting piece, which further includes a screw hole and a positioning hole communicating with said screw hole. The flexi-PCB is configured, such as by virtue of cut-out portions or by inherent elasticity, to be bendable a out non-parallel axes. Each cutting edge of the center bit comprises first and second part edges joined by a transition edge portion.