Sheathed catheter system for fluoroscopically guided retrograde catheterization, and brush and forceps biopsy of the upper urinary tract.

A sheathed (coaxial) ureteral catheter has been designed for use in fluoroscopically guided retrograde procedures. Once the catheter has been inserted into the ureter the inner section is removed, leaving a semiflexible sheath as a conduit for biopsy forceps, curved catheters and other instruments. The sheath facilitates ureteral stenting, forceps biopsy of the renal pelvis and brush biopsy of all calices. The sheath also helps in percutaneous stone extraction by allowing retrograde passage and removal of balloon catheters with the patient in the prone position. Cystoscopy is needed initially to insert the catheter but not to pass instruments through the sheath. Thus, procedures can be completed in a standard fluoroscopy room.