Changes

===Removal of previous catheter===

*Check the position of the previous catheter tip with a few ml of iodinated contrast (enough to delineate the renal pelvis but yet not obscuring the catheter tip), preferably in two projections such as a lateral and a more frontal one.* <br>''[[#Troubleshooting|Troubleshooting: Catheter in calyx]]''

*Insert a guidewire (such as Amplatz) into the renal pelvis or proximal ureter.* <br>''[[#Troubleshooting|Troubleshooting: Cannot advance guidewire]]''

*Remove the previous catheter while keeping the guidewire in place<ref group="notes">Always keep at least one hand on the guidewire. The grip needs to be switched to just above the skin as the catheter tip exits.</ref>.* <br>''[[#Troubleshooting|Troubleshooting: Catheter stuck]]''