ESWL is delivered in a medical bath or via a water cushion.
Extracorporeal shock wave lithotripsy refers to a method of breaking up kidney stones. The theory is that shock, or sound, waves directed at the kidney will pass through soft tissue but will hit the hard material of the stone and break it up into fragments that can pass easily through the rest of the urinary system. There are many advantages to this procedure over alternatives, but it is not without risks.
Major Risk
The kidney is the target of lithotripsy.
Kidney stones are formed from small crystals that accumulate in the kidney or other parts of the urinary tract. These stones -- also called renal calculi -- are common and have several causes. In ESWL, shock or sound waves fragment the stones so they can pass more easily. In rare occasions the kidneys may be damaged by the procedure and may shut down. Bruising to the kidneys can also cause pain and blood in the urine. ESWL is not possible during pregnancy or severe obesity and may be contraindicated for people with pacemakers.
Minor Risks
There are several minor risks associated with the procedure. There may be some pain as the fragments pass down the ureter -- tube that leads to the bladder -- but this will be less than the pain caused by a larger stone. In some patients there may be a resulting urinary infection. The possibility of discomfort from the procedure itself is remote. Some studies have shown increased rates of type 2 diabetes and hypertension, but the American Urological Association asserts those conditions may have been pre-existing.
Unsuccessful Procedure
On rare occasions ESWL does not work. Either the stone is not broken up into small enough pieces, leaving larger pieces that can lodge in the urinary tract and cause pain, or the procedure may have to be repeated. If the procedure does not work, surgery may be necessary to remove the stone or fragments manually.
Risks of Recurrence
Many types of kidney stones are more common in men, with the exception of those caused by urinary tract infections, which are more common in women. The stones tend to recur and they seem to run in families. Many people have more than one episode, particularly if there is an underlying disease causing the stones, such as gout.
Advantages of ESWL
According to the American Urological Association, the advantages of ESWL outweigh the risks. Surgery and other mechanical procedures -- such as ureteroscopy -- are more risky than ESWL, and passing the stone whole is very painful. Watchful waiting can lead to swelling of the kidneys and extreme pain, even kidney failure. Though ESWL is not without some risk, hundreds of procedures are performed each year with no adverse long-term consequences. The AUA says about one person in 10 experiences problems.
Tags: risks, eswl, urinary tract, American Urological, American Urological Association, cause pain, does work, more common, rare occasions, shock sound, shock sound waves
