Patent ID: 8821485

Claim:
A method of performing a catheter-based procedure, the method comprising: introducing a delivery sheath inside a patient's body; advancing a secondary sheath through the delivery sheath, toward a treatment site inside the patient's body, wherein the secondary sheath is distinct from the delivery sheath, coaxial to the delivery sheath along at least a portion of a length of the delivery sheath, and has a default linear shape that is substantially free of radial bias, the secondary sheath having a length that is shorter than a length of the delivery sheath, the secondary sheath further comprising a push member having a distal end attached to a proximal end of the secondary sheath, wherein a combined length of the secondary sheath and the push member exceeds a length of the delivery sheath; introducing a catheter through the delivery sheath and secondary sheath, to the treatment site; and performing a procedure at the treatment site with the catheter, wherein performing the procedure comprises performing the procedure while maintaining at a relatively fixed position the secondary sheath.