There are now many methods of treating stones in the kidney or ureter.
Lithotripsy is one method. Stones can be broken up by focusing pressure waves onto them from a lithotriptor – this is known as ‘Shock Wave Lithotripsy’ – SWL for short.
The Stone Management Unit at Southmead Hospital has been treating patients with lithotripsy since 1988. In November 1999 we installed a new lithotriptor – a Dornier Lithotriptor S – which has the ability to visualise stones either by x- ray or ultrasound.
The energy waves produced by the machine are accurately focused on the stone and travel through the body tissues without damaging them; the energy is dispersed to break up the stone – reducing it to ‘sand’ or ‘gravel’ – which is then passed in the urine usually with no pain.
Before treatment you may receive a pre-med, this is not a sedative but a mild pain killer. Once in the treatment room you are positioned on the treatment table and the exact position of the stone checked by x-ray or ultrasound. The pressure wave generator is placed against the skin and the energy waves produced. This may cause mild discomfort. If you experience pain treatment will be stopped and medication to control the pain given.
The majority of patients are treated as day cases, spending 3-4 hours on the ward. Please bring your own dressing gown and slippers. You will not be able to drive yourself home after treatment. Please tell the Co-ordinator of the Stone Management Unit if transport is a problem (0117 959 5175).
The treatment usually takes between 45 and 60 minutes, during which time you can listen to CDs on headphones (you can bring your own CDs if you wish). During the treatment you will be aware of the noise of the pressure wave generation but this sound is not disturbing. You will be required to lie still through the treatment so that the position of the stone does not alter.
It is quite common for more than one treatment to be necessary.
Complications are unusual after SWL. Occasionally there is a small amount of bruising of the skin. Immediately after treatment many people notice that they pass a small amount of blood in their urine but this clears up within a few hours; we will ask you to remain on the ward until your urine has cleared.
There may be some discomfort for up to a couple of weeks as stone fragments pass. This is usually controlled by simple pain killers but if these do not work or if you feel you have any flu-like symptoms with a high temperature or other complaint suggestive of urinary tract infection, please contact the unit between 8am and 5pm. If out of hours, or if you fail to make contact with the unit, contact your G.P and give him/her the information sheet supplied on your discharge.
Limitations Of Lithotripsy
Lithotripsy works in two patients out of three. If the stone fails to fragment it may be necessary to proceed to a ureteroscopy under a separate admission. This involves general anaesthetic and usually a two night stay hospital. The procedure does not involve an incision of any kind and may involve insertion of an internal stent (see link). You will receive more details of this treatment upon admission.