A B C D E F G H I J K L M N O P R S T U V W

LITHOTRIPSY

Why is Lithotripsy performed ?

Stone can develop in any part of the urinary tract: from the kidney and the ureters (the tubes which take the urine from the kidneys to the bladder), to the bladder itself. Stones which are lower in the tract can often be removed comparatively easily, or pass by themselves. To avoid the need for either operation or a wait-and-see approach, the technique of lithotripsy was developed, a process to disintegrate the stone from outside the body.

Preparations needed for Lithotripsy

Sometimes the urologist will advise that a small internal tube (J stent) be inserted prior to lithotripsy. This is to help the passage of the stone fragments produced by the lithotripter. It is inserted through the external opening of the bladder under a general anaesthetic.

What Happens during Lithotripsy

Lithotripsy is also known as ESWL (extracorporeal shock wave lithotripsy). There are many different types of machine, but they all rely on the same principle. A shock wave is generated electrically and is focused precisely on the stone. X-rays or ultrasound are first used to visualize the stone so that the target can be at the focus of the shock waves throughout the treatment. The shock wave is a physical source of energy. No electric current passes through the body. The energy of the shock wave is only delivered to the hard surface of the stone and passes harmlessly through the soft tissues of the body. Most lithotripter machines are designed to work on an outpatient basis. Either no form of anaesthesia or sedation alone is required during treatment. This means that you will be able to return home after a 2-hour recovery period. Each treatment takes about an hour to complete. You will need to lie on a couch and your loin positioned over a water-filled pad or dish and the stone is located. If sedation is required, an intravenous injection is given. The shock waves are delivered at one second intervals. A clicking noise is evident and there may be discomfort in your loin or your back. Pain should not occur. The operator is present throughout the procedure so that the treatment can be stopped if the discomfort is severe. The number of treatments required is entirely dependent on the size and consistency (hardness) of the stone and on the power of the lithotripter. The urologist and the operator will be able to tell you exactly how the treatment is progressing: after each treatment or before the next, an x-ray is taken to see how the stone has changed. Some lithotripters may require you to have a general anaesthetic. This is usually because they are more powerful and the shock waves would therefore cause pain. These machines tend to treat the stones more quickly but at the cost of a general anaesthetic.

Possible Complications during Lithotripsy

Sometimes the stone fragments do not pass easily. This may cause a colicky pain and be a signal that the urologist should be contacted. Because this is not uncommon, precise plans will be made with you, should there be any complication. Occasionally if the stone fragments become stuck, a procedure will be required to remove them (ureteroscopy). Some degree of bleeding is common after lithotripsy. This is seldom heavy, and should settle by itself. Urinary infection may have existed (because of the stone) even before treatment commenced. Generally antibiotics will be prescribed during lithotripsy. If symptoms of infection such as pain, fever or a burning sensation on passing urine develop during treatment, contact the urologist. If an internal tube has been passed (J stent) prior to lithotripsy, you may experience discomfort. This can be severe and consists of a severe burning when passing urine and extreme urgency. It is impossible to predict which patients will be affected badly by a J stent. Patients who do experience these problems are treated quickly so that the stent can be removed early.

After Lithotripsy

Follow-up is always necessary. Stone recurrence is not uncommon. At the first x-ray sign of a further stone developing, you will be advised to have lithotripsy before the stone becomes a problem.

If Lithotripsy is not performed

Although this method of dealing with stones in the urinary tract is very satisfactory, an operation through the abdomen is a possible alternative way of removing them. This of course requires a general anaesthetic. Small stones may pass through to the bladder and be passed with the urine of their own accord, but this is not an acceptable approach except with the smaller stones. If left behind, larger stones can lead to infection in the kidney and also to temporary or permanent damage to kidney function.