Treatment of Kidney Stones

There are various treatment options for kidney stones and the treatment depends on a variety of factors, including the size and location of the stone in the kidney, symptoms and attendant complications of stones such as hydronephrosis (dilation of collecting system of the kidney).

The options range from observation, medical expulsion therapy (MET), extracorporeal shockwave lithotripsy (ESWL), percutaneous nephrolithotomy (PNL), ureteroscopy (URS) and retrograde intrarenal surgery (RIRS)

Observation

Small stones that are asymptomatic i.e. no pain, bleeding, infection, etc can be observed. Sometimes, these stones may be passed out spontaneously. Nevertheless, these stones should preferrably be monitored with serial imaging.

Should the stone increase in size, migrate to the ureter (tube that connect the kidney to the bladder) or become symptomatic, treatment should then be considered.

Spontaneous passage & medical expulsion therapy (MET)

Small stones in the lower ureter can pass out spontaneously. The likelihood of spontaneous passage can be increased with medication. The medication usually used is an alpha antagonist. It may take a few weeks for the stone to pass out.

Should the stone remain despite medical expulsion therapy or become symptomatic, then other treatment options should be considered.

Extracorporeal Shockwave Lithotripsy (ESWL)

This method uses shockwaves to break stones. Shockwaves are applied from outside the body (extracorporeal) and directed towards the kidney stones. Under x-ray or ultrasound guidance, these shockwaves target at the kidney stones and cause stone fragmentation. The stone fragments are then passed out spontaneously.

Shockwaves are delivered through a machine called lithotripter and effective for kidney stones up to 20 mm in size or 10 mm if the stone is in the lower pole (lower aspect of the kidney collecting system). It is also effective for stones in the upper portion of the ureter and this process can be performed as an outpatient procedure.

Percutaneous Nephrolithotomy (PNL)

This is a procedure where stones in the kidney are accessed via a channel that is created from the surface of skin to the kidney. This is accomplished using x-ray and / or ultrasound imaging and a variety of specialised instruments. Upon accessing the stone, it can then be broken into small pieces and the stone fragments retrieved.

It is a minimally invasive surgery requiring hospitalisation and is effectively for larger stones in the kidney.

Ureteroscopy (URS)

This involves direct visualistion of the ureter via a ureteroscope. A ureteroscope is an instrument that is passed from outside the body into the bladder and thence into the ureter. Through the scope, stones in the ureter can be seen and then fragmented using a variety of stone-fragmentation devices. This is usually performed as a day-case.

Retrograde intrarenal surgery (RIRS)

This is a special type of ureteroscope and it can reach not only the upper portion of the ureter but also the kidney. Thus it is useful for remnant stones in the kidney, following other procedures, or stones in the upper ureter. Again, this is usually performed as a day-case.