Lithotripsy
What is lithotripsy?
Extra corporeal Shock Wave Lithotripsy (EWSL) is a modern, non-surgical way of treating kidney stones. You will require some form of pain relief (for the treatment itself) but you do not need to have a general anaesthetic, unless stated otherwise by the Urology Consultant. Ultrasound equipment and x-ray screening is used to provide a precise image of your stone. Pulses of energy are then aimed at your stone (equipment explained later on) causing mini shock waves, which will break down the stone. Initially, these shock waves will ‘weaken’ the stone, not necessarily break it completely. Therefore, you may need more than one session of Lithotripsy to get rid of the stone.
What are the alternatives?
The main alternative treatment is telescopic surgery, open surgery or observation to allow spontaneous passage.
What will happen to me when I come into hospital?
When you arrive at the department the nursing staff will prepare you for the treatment. This usually involves a quick admission procedure when you will be asked some questions, sign a consent form and be given some form of pain relief. It is important that the staff know if you may be pregnant (Lithotripsy cannot be carried out if you think you are pregnant). The nursing staff will need to make sure that you are not taking any medications to thin your blood (also known as anti-coagulants – such as Warfarin or Aspirin), if you have a pace-maker in situ and if you have any problems with high blood pressure. If you are not feeling well, on the day of your treatment, and think you may have a temperature, please tell the nursing staff. During the admission feel free to ask the nursing staff any questions about the treatment. We will also be more than happy to answer any further questions you may have. It is important that, during the treatment, you are as relaxed as possible, so please feel free to talk about your anxieties.
Before the treatment you will be given some pain relief tablets and/or a pain relief suppository. It is important that you take these, as the procedure can be quite painful without them. Some of the painkillers can make you feel a bit ‘sleepy’, so please arrange for someone to pick you up after the treatment. The nursing team may give you a hospital gown to wear for the treatment. You do NOT need to take your underwear off – please keep them on!
What will happen to me during the treatment?
When you are ready you will come into a room where the Lithotripsy equipment has been set up (all equipment is mobile). You will be met by two, friendly technicians, who will explain things to you, if you have any questions. Once you are familiar with our set-up we will ask you to lie on our treatment table, usually face down. This is purely because the kidneys are situated towards the back of the body, and so we can treat you more effectively this way. However, if you have a stone in either of your ureters (the tubes from the kidneys to the bladder), then it may be easier to treat you if you are lying on your back. The ureters come down from the kidneys towards the front of the body, into the bladder. Once you are comfortable on the treatment table we will ask you not to move and also to keep your breathing as shallow as possible. This is important because we will locate the stone, using the x-ray or ultrasound machine. When that is done we will ‘line-up’ the Lithotripter (the machine that delivers the shock waves) to your back/front. The x-ray machine is linked, via sensors, to the Lithotripter so that we get a precise image of your stone as well as treat it accurately and effectively. Movement will hinder the effectiveness of shock wave delivery, which is why it is important that you do not move and control your breathing.
Before we put the Lithotripter treatment head (a cushion with water inside) to your back/front we will put some warm ultrasound jelly on the area where the treatment head will go. The purpose of this is to create a good seal between your skin and the cushion. The jelly is water-based and will wash off. When we are happy that the stone is in the correct target area (we can see this on a screen) we will start the treatment. The treatment will usually last about 20 minutes. You will hear a ‘clicking’ noise and feel something like a ‘flicking’ on your back/front. Some people have said that it feels a bit like a small electric shock. During the treatment time we will slowly increase the power/intensity. It is important that we get to a good level of power to ‘break/weaken’ the stone. It may feel uncomfortable but should be bearable so if it gets too painful, just let us know. We can adjust the level at any time.
During your treatment we will monitor the stone, to make sure that it hasn’t moved. We may need to move the table a little during the treatment to make sure we are accurately treating the stone. Sometimes a stone will change shape/start to fragment during the treatment. We may be able to see this on our x-ray machine. Other times the ‘breaking’ down’ process takes a bit longer. Some stones are very hard and need more than one treatment.
What happens after?
After your treatment session you will go back to the nursing staff who will give you refreshment and possible keep you on the ward for a while (depending on the pain relief you have had). The nursing staff will also advise you on what to do when you leave the hospital. Below are a few pointers:
• It is extremely important that you drink 2-3 litres of fluid each day after your treatment, for up to seven days. Increased fluid will ‘flush out’ the kidneys and aid the ‘breaking-down’ process. If you don’t drink, the treatment will NOT work!
• Stay as active as you can after the treatment. Swimming is particularly good as it aids the ‘flushing out’ of stone particles. Walking is also good.
You may see some blood in your urine, after treatment. This is quite normal – just increase your fluid intake.
A bruise on your back (where the treatment head was placed) is also quite normal. However, you must contact your GP if you experience any of the following:
• A fever or if you feel generally ‘unwell’.
• If you have difficulty or inability passing urine.
• If you have severe pain in your kidney, back or surrounding area.
You will most likely be given a ‘follow-up’ x-ray form so that the urology team can see how the treatment worked. If, after the x-ray, you still have the stone or some fragments, then you will need to have some more Lithotripsy. It is quite common to require more than one session to get rid of the stone.
What are the known risks of lithotripsy?
Common risks
• Bleeding on passing urine for a short time after treatment
• Pain in the kidney as small fragments of stone pass after fragmentation
• Urinary tract infection from bacteria released from the stone when fragmented needing antibiotic treatment
Occasional • Stone will not break as too hard requiring an alternative treatment
• Repeated ESWL treatments may be required
• Recurrence of stones
Rare • Kidney damage (bruising) or infection needing further treatment
• Stone fragments occasionally get stuck in the tube between the kidney and the bladder requiring hospital attendance and sometimes surgery to remove the stone fragment
• Severe infection requiring intravenous antibiotics and sometimes drainage of the kidney by a small drain placed through the back into the kidney
