What is extra corporeal shock wave lithotripsy?

Extra corporeal shock wave lithotripsy is a technique for treating stones in the kidney and ureter (without surgery). High-energy shock waves are used to break stones into pieces as small as grains of sand. Because of their small size, these pieces can pass from the body along with the urine.

What does the treatment involve?

Using x-rays or ultrasound to pinpoint the location of the stones, the body is positioned so that the stones are targeted precisely. About 2500 pulses are usually needed to crush the stones. The complete treatment takes about 45 to 60 minutes.

What are the advantages and disadvantages of this treatment?

The main advantage of this treatment is that many patients may be treated for kidney stones without surgery. As a result, complications, hospital stays, costs and recovery time are reduced. Unfortunately, not all types of kidney stones can be treated this way. In addition, stone fragments are occasionally left in the body and additional, treatments are needed.

Does the patient need anesthesia?

In general, some type of sedation is used to help the patient remain still and to reduce any discomfort. Anaesthesia may be necessary in young persons and for persons who are very sensitive to pains. Usually, the patient will be asked not to drink or eat anything for 6 hours prior to the procedure, or after midnight of the previous night, if the procedure is in the morning. If he take regular medicines, he should ask his consultant if they are safe to take before the procedure. For instance, the patient may be asked to stop taking ASPIRIN and similar other drugs that interfere with blood clotting several days before the treatment.

The patient should tell her consultant if she is pregnant, because lithotripsy must not be performed during pregnancy.

Does the patient need to be hospitalized?

Lithotripsy may be done on an outpatient basis. In some cases patients are hospitalized for a day.

Larger stones can cause a blockage in the ureter if the fragments jam the ureter after being broken. To avoid this a tube known as a JJ or Double J stent can be used at the discretion of the Urologist.

Double J Stent

Double J stents are small tubes, which pass from the kidney to the bladder.

They are called JJ stents because the top and bottom have a curled end to prevent migration of the stent.

Some times stents irritate the bladder and make the patient feel as if there is need to pass urine more often. This sensation usually pass off after a few days.

The stent also stop the normal one-way valve at the base of the bladder, urine therefore can pass up to the kidney when the patient passes urine, and this is felt as an ache during passing urine.

At the end of passing urine an odd sensation is usually felt in the lower abdomen.

Stents are removed under local anesthetic with a small cystoscope. The procedure is not painful.

Stones can form on the end of stents if they are left in the body too long. The patient should make sure that their stent is removed in time.

What can the patient expect after treatment?

After treatment is complete, the patient can move about almost immediately. Many people can fully resume daily activities within a day. Special diets are not required, but drinking plenty of water helps the stone fragments pass. Some pain may occur when the fragments pass, which begins soon after treatment and may last for up to one to two weeks. Oral pain medications and drinking lots of water will help relieve the symptoms.

What are the complications or side effects?

Most patients have some blood in the urine for a few days. The shattered stone fragments may cause discomfort as they pass through the urinary tract.

Can all kidney stone patients have this kind of treatment?

No. The size, number and location of the stones are factors that must be taken into account when exploring treatment options. The doctor can decide whether this is the best treatment for the patient. In some cases, extra corporeal shock wave lithotripsy may be combined with other forms of treatment.

How successful is this type of treatment?

In those patients who are thought to be good candidates for this treatment, about 80 to 90 percent are found to be free of stones within three months of treatment. The highest success rates seem to be in those patients with mobile stones that are located in the upper portions of the urinary tract (kidney and upper ureter). After treatment, some patients may still have stone fragments that are too large to be passed. These can be treated again if symptoms persist.