Ureteroscopic lithotripsy (URS)

Ureter stone
Rigid vs flexible ureteroscope

This is the endoscopic treatment of ureter stones using a mini-scope. Under general anaesthesia and fluoroscopic xray guidance, a rigid or flexible ureteroscope is passed up the ureter via the urethra.

The stone is broken into smaller pieces with the Holmium laser. These tiny stone pieces will pass out on their own. A wire basket can also be used to trap the stone or extract the broken pieces. This surgery takes 30 mins on average and can be done as a day case under general anaesthesia.

Holmium laser to break the stone
Dormia basket to trap / extract the stone

Occasionally, a double-J (DJ) stent may need to be inserted after the procedure should there is any injury to the ureter wall or if there is prior gross hydronephrosis of the kidney from an impacted stone. The success rate for stones lodged in the lower ureter is near 100%. For stones lodged at the mid- to upper ureter, there is a chance they may float up into the kidney. If the flexible ureteroscope is used, this is not an issue as the scope can flex backwards within the kidney calyces to find the stone. However, if the rigid ureteroscope is only available, then the floated-up stone cannot be treated and a DJ stent is inserted for subsequent ESWL.

Dr Chin doing URS surgery

The advantages of URS over ESWL is that even hard stones can be broken and the ureter opening can be dilated to facilitate subsequent stone passage. However, URS is a more expensive and more invasive way of breaking ureter stones.

Complications include:

  • bloody urine. This should clear in a few days.
  • infection This occurs post-operatively and is due to bacteria released when the stone is broken. This can be minimised by giving antibiotics prior to surgery.
  • perforation of the ureter. If this happens, urine leak and pain results. A DJ stent will need to be inserted to prevent further urine leak and avoid a late stricture
  • stone migration. Because pressurised water is used to access the ureter and visualise the stone, the pressure may accidentally push the stone up beyond the reach of the ureteroscope.

Desired outcomes:

  • no ureter injury
  • complete stone breakage