What are my treatment options for urinary stones?
This depends on several factors including stone size, hardness and location. It also depends on the problems the stone may be causing such as damaging a kidney or presence of infection. A CT scan (sometimes combined with an X-ray) will give your doctor most of this information. Some stones may even dissolve with medication over time and some may just require observation. This article focuses on the surgical management of stones.
For stones in the ureter
The ureter is the tube which drains urine from your kidney to your bladder. Stones in this location may be very painful. They can cause blood in the urine and can become infected, causing fever and sepsis. In uncomplicated cases, where there is no kidney damage or infection, and your pain settles, your urologist may recommend that you give the stone a chance to pass. This is usually done for stones less than 1cm and is particularly useful for stones which have moved closer to the bladder. Your doctor may prescribe pain medication as well as a special tablet to help relax the ureter (kidney tubes) and aid in the passage of the stone.
If however, you don’t pass your stone or if your stone is too large, you will require an intervention. You may require intervention if your pain does not settle, if you get an infection, if your doctor thinks you may have kidney damage or if you only have one kidney.
If your kidney is blocked and you have kidney damage or a fever, your urologist may opt to place a stent into your kidney. This is usually done under anaesthesia and we do this via your urine passage – there is no cut. The stent allows urine to drain from the kidney to the bladder. Stents may cause irritation and even some bleeding. Alternatively, if stenting is not possible or you are particularly ill, your urologist may place a tiny tube through your back in order to drain urine. This is called a nephrostomy tube and you will need to wear a bag temporarily. Neither of these options will treat your stones, however, and you will eventually need definitive treatment. Please note that a stent should not stay in longer than a few months without being exchanged and is not a permanent treatment. Keeping it in longer than prescribed may result in stones forming on the stent and could lead to loss of a kidney.
What are the surgical options for treating ureteric stones?
Ureteroscopy: This involves passing a very long, thin instrument up the ureter. You will need anaesthesia for this procedure. The instrument has a camera at the end of it and we can therefore look at the stone directly. This enables us to break the stone with a laser or special stone breaker. Often, the urologist may leave a stent in place for a few days. Your urologist will be happy to discuss the procedure and its potential complications which are uncommon and include bleeding, infection and injury to the ureter.
Extracorporeal shock wave lithotripsy (ESWL): This machine generates shock waves to break up kidney stones without making a cut. This is a same day procedure and you do not need to go to sleep but may require some sedation. The San Fernando General Hospital has an ESWL machine which is accessible to the public free of charge. Not everyone is suitable for ESWL and if your stone is too hard or you are very overweight, this may not be right for you. Once the stone breaks, you will pass out the tiny pieces. Occasionally multiple sessions are necessary to clear the stone and sometimes fragments get stuck, requiring further surgery. Your urologist will be happy to discuss this with you.
If neither of these options are available at your hospital, your urologist may opt to make a cut and remove the stone.
What are the options for treating stones in the kidney?
Both ureteroscopy and ESWL may also be used for stones in the kidney but are generally used for smaller stones. We generally do not offer ESWL for stones larger than 2cm and for stones which are in the lower part of the kidney, our limit is usually 1cm. Larger stones may require a nephrolithotomy which simply means extracting the stones from your kidney via a cut. This was previously done via a cut on the side of your body just below your ribs and many urologists still offer this method – the size of the cut varies considerably with surgeon skill, varying from an inch-and-a-half to almost 12 inches in some cases.
Fortunately, the procedure may also be done via a tiny cut through which a camera is passed into the kidney – this is called a Percutaneous Nephrolithotomy (PCNL). The stone is then shattered using a stone breaker or laser. A tube may be left in the kidney and if all goes well, is removed the following day. Occasionally, for very large stones, you may need a second procedure or even a session of ESWL to treat residual stones. If this is the case, the urologist may leave a tube in place to allow him easy entry into the kidney next time. You will need blood donors for this procedure as bleeding is a risk.
Dr Satyendra Persaud is a lecturer in urology at the University of the West Indies and is responsible for both undergraduate and post graduate teaching. He is a consultant based at the San Fernando General Hospital and is co-ordinator of the Residency Program in Urology. He is a Fellow of the Royal College of Surgeons of England.