ureteral stone is a stone that is in the ureter (the narrow duct that drains urine from the kidney to the bladder). Once a stone enters the ureter, it will either pass or it will need to be removed.
Ureteral stones and size
- Large stones generally cause symptoms as soon as they enter the ureter.
- Some larger stones are big enough to have irregular shapes, so they may not completely obstruct the ureter or cause severe symptoms.
- Smaller stones often make their way further down the ureter before they are noticed.
- Small smooth stones are often associated with more severe pain because they are more likely to completely obstruct the ureter.
Stone symptoms occur when a stone gets stuck. Stones are commonly discovered at these three locations:
- The start of the ureter
- Two-thirds of the way down the ureter
- Near the bladder
A single stone may cause symptoms at any or all of these locations. Unfortunately, the severity of pain and number of attacks vary from person to person and aren't good indicators if a stone will pass on its own.
Reasons to leave a ureteral stone untreated
- Smaller stones are more likely to pass
- Stone location - the farther a stone progresses, the better its chances of passing.
- Previous successful stone passage - patients who have successfully passed stones in the past will often do so again.
- Patient who wish to avoid surgical intervention will often tolerate episodes of discomfort.
These factors support pursuing a trial of passage.
What is "trial of passage"?
When a ureteral stone has a reasonable chance of passing by itself, we support the patient through this process. Depending on the size, location and symptoms, follow-up CT scans are performed every one to two weeks. Patients are closely monitored for signs of trouble.
What if I pass the stone?
If the stone passes, it is important to save it and bring it into the clinic. An analysis of the stone's composition may provide important information to help you prevent future stones.
When treatment is required
Treatment is always available if the stone fails to progress down the ureter or begins to cause more severe symptoms. Surgical stone removal is available on a prompt basis when necessary. In general, we allow about one month for a stone to pass if symptoms are tolerable.
Reasons to treat a ureteral stone
- Larger stones are less likely to pass
- Stone location - the farther a stone needs to move, the less likely it is to do so.
- Previous stones that didn't pass - patients who have had trouble in the past, often will again.
- Duration of symptoms - treatment is recommended if a stone hasn't progressed within one month.
- Patient preference - many patients want the stone removed as quickly as possible.