A method and dissecting device are disclosed for treating a stenotic vessel. The method including inserting a dissecting device into a subintimal space of a blood vessel； dissecting an inner side of the subintimal space from an outer side of the subintimal space over an entire circumference of the blood vessel with the dissecting device, the dissecting device including a first dissecting member having a first cutting member； and removing the dissected inner side of the subintimal space and a stenotic region attached to the inner side of the subintimal space from the blood vessel.
