A method of performing a percutaneous vascular procedure includes sliding a vascular constriction crossing mechanism in a proximal to distal direction over a wire guide having a wire guide tip positioned at a proximal side of a vascular constriction, and rotating a sheath of the vascular constriction crossing mechanism about an axis of rotation relative to another sheath of the vascular constriction crossing mechanism. The method further includes advancing a constriction crossing tip by way of helically engaging the sheaths during the steps of rotating, and guiding an intraluminal treatment device into or past the vascular constriction for performing a vascular procedure within the patient. The vascular constriction crossing mechanism includes a first sheath and a second sheath, and a constriction crossing tip coupled with a distal segment of the first sheath. The vascular constriction crossing mechanism further includes a helical coupling between the first and second sheaths, which is configured to convert a torque on one of the sheaths to an axial force on the other of the sheaths for crossing a vascular constriction with the constriction crossing tip. An anchoring mechanism may be coupled with one of the sheaths and includes a deployed state at which the anchoring mechanism contacts a vascular wall of the patient for resisting displacement of the second sheath within a vascular structure of a patient.
