Catheter system with highly flexible distal portion for distal access and/or clot removal

A method for accessing a blood vessel using a catheter coupled at a proximal end to a handle, the method comprising:

• causing an elongated tube of the catheter coupled to the handle to assume a contracted state by moving a first actuator of the handle along a first channel to a distal most position, the first actuator coupled to an actuator tube of the catheter disposed within the elongated tube and configured to move axially with respect to the elongated tube, the elongated tube coupled at a distal end of the elongated tube to an actuation wire disposed within the actuator tube;
• engaging the first actuator with a second actuator positioned along a second channel of the handle to lock an axial position of the actuator tube with respect to the elongated tube thereby locking the elongated tube in the collapsed state, the second actuator coupled to an intermediate tube disposed within the elongated tube;
• navigating a distal end of the catheter distally towards a target site in the blood vessel while the elongated tube is locked in the contracted state;
• and
• unlocking the first actuator from the second actuator and moving the first actuator proximally with respect to the first channel to cause the elongated tube to transition from the contracted state to the expanded state at the target site.