A ureteric stent involves the insertion of a thin tube into the ureter to prevent the obstruction of urine flow from the kidney. A doctor often uses a ureteric stent after the ureter becomes obstructed during a procedure or due to kidney stones, tumors, infection or blood clots, states the Radiological Society of North America.
Prior to insertion of a ureteric stent, it is common for the patient to receive an ultrasound, a CT scan or an MRI. A health care worker shaves and sterilizes the area where the catheter is to be inserted and covers the area with a drape. During the procedure, the patient lies on his stomach, and the doctor uses a fluoroscope to find the ureter. He inserts a guide wire into the ureter and then runs the stent over the guide wire, directing it to its permanent position inside of the ureter. The doctor removes the guide wire after placing the stent, but sometimes a nephrostomy catheter remains in place for a few days, according to the Radiological Society of North America.
A doctor inserts a nephrostomy catheter using a similar method to the ureteric stent. Upon completion of the procedure, the doctor removes the catheter and applies pressure to the insertion area to stop any bleeding. A nephrostomy catheter is usually connected to an external bag that collects urine, explains the Radiological Society of North America.