Patent ID: 8888787

Claim:
A method for exchanging a puncture wire for a working wire in creating a tract for nephrostomy tube creation comprising the steps: a) providing a puncture wire having a tissue penetrating tip shielded in a sheath, the puncture wire slidable within the sheath and releasably lockingly engaged thereto and the sheath retractable with respect to the puncture wire in an antegrade direction; b) inserting the puncture wire and sheath in a retrograde direction through a working channel of an ureteroscope to exit a channel of the ureteroscope; c) releasing the puncture wire from the sheath; d) advancing retrograde the puncture wire from within a selected calyx through a flank of a patient; e) inserting over the puncture wire in the antegrade direction a flexible coaxial catheter having a length of between about 20 cm to about 50 cm, the coaxial catheter having an outer catheter and an inner catheter, the outer catheter positioned over the inner catheter, and the coaxial catheter inserted into the ureter, the coaxial catheter inserted over the puncture wire so that the flexible coaxial catheter is a first member inserted over an exposed penetrating tip of the puncture wire after the penetrating tip of the puncture wire extends from the flank of the patient; f) removing the puncture wire and inner catheter from the coaxial catheter; and g) inserting a wire in the antegrade direction through the coaxial catheter.