Ureteral stent (double-J stent)

The ureteral stent does not treat stones by removing them, but may be necessary in some situations, in particular if acute kidney pain (renal colic) is present. A catheter is introduced into the ureter under cystoscopic guidance.

This ensures that the urine can flow from the kidneys into the urinary bladder, thereby treating the direct cause of the colicky pain. In most cases, the stone subsequently needs to be removed using one of the two techniques described below.

Abdominal x-ray image
On the right: Ureteral stent shown in red, cystoscope for cystoscopy in yellow, urinary bladder outlined in green

Ureterorenoscopy

This technique is used at the University Department of Urology Tübingen as the standard treatment of kidney and ureteral stones. Depending on the location of the stone, an endoscopy of the ureter and the renal pelvis is performed using a rigid or flexible instrument. The stone can usually be removed directly using a loop. Larger stones are first fragmented using a laser or a kind of pneumatic chisel and then removed. At the end of the procedure, a ureteral stent is usually placed to prevent intense pain (renal colic) caused by mucosal swelling after the procedure. This stent has to be removed again after a few days under cystoscopic guidance.

Rigid endoscope used for ureterorenoscopy (ureterorenoscope)

Removal through the skin (PNL, percutaneous nephrolitholapaxy)

Depending on the location and size of the stones, ureterorenoscopy is not always the best technique to use. In such cases, a small tube can be introduced into the kidneys via a skin incision of about 1 cm in size under ultrasound guidance. This tube allows for removing even larger stones without any problems. Conventional PNL has been increasingly superseded by the minimally invasive form of PNL using small instruments and access ways and is now also the preferred method of “percutaneous stone removal” at the University Department of Urology Tuebingen.

On the left: Special prone position required for PNL
On the right: Illustration of PNL using an endoscope for renoscopy (right hand of surgeon) and a lithotripter (left hand of surgeon)

Extracorporeal shock wave lithotripsy (ESWL)

Extracorporeal shock wave lithotripsy (ESWL) is a technique used to fragment kidney stones and some ureteral stones by means of shock waves. These shock waves are concentrated sound waves that are directed at kidney or ureteral stones under x-ray and ultrasound guidance.

This way, the stone is fragmented, enabling it to leave the kidney in a natural way without causing intense kidney pain (renal colic).

In the case of very large stones, ESWL can facilitate their subsequent surgical removal. The advantage of ESWL is that the treatment can be carried out without anaesthesia.