Small kidney and ureter stones often come off by themselves. As long as they do not cause severe discomfort or complications, no intervention is necessary. Larger stones usually have to be treated. Depending on their position and size, they are then shattered or removed by endoscopic surgery.
Most stones with a diameter of less than 5 millimeters come off on their own, as do half of all stones between 5 and 10 millimeters. Such small stones are often excreted with urine after one to two weeks.
If it is foreseeable that a stone will be washed out by itself, one usually waits. If discomfort occurs while the stone is moving through the ureter, pain killers such as ibuprofen or diclofenac can help.
Larger stones cause discomfort and usually have to be shattered or removed by surgery. This is necessary if
a stone is not excreted within four weeks,
it comes to complications,
strong colics occur or
the stone is larger than 10 millimeters.
Uric acid stones can sometimes be dissolved by medication.
Do medicines help with kidney and ureter stones?
Medications from the alpha blocker group are intended to facilitate the excretion of the stones. They relax the muscles in the lower part of the bladder. Alpha blockers are drugs for the treatment of benign prostate enlargement. They are not approved for the treatment of kidney and ureter stones. In particular, the alpha blocker Tamsulosin is sometimes used off-label.
According to current research, alpha blockers can support the elimination of stones. This is shown by an evaluation of 67 studies for urinary stones with a size of about 5 to 10 millimeters:
Without alpha blockers, about 50 out of 100 people lost the stones within four weeks.
With alpha blockers, about 73 out of 100 people lost the stones within four weeks.
The therapy thus helped 23 out of 100 people to remove the stone.
Temporary side effects of alpha blockers are low blood pressure, dizziness and fatigue. In a large study, 4 out of 100 people discontinued treatment due to such side effects. In 5 out of 100 men, the drugs also temporarily led to a “dry ejaculation” (retrograde ejaculation). The seminal fluid is released into the urinary bladder and hardly or not at all to the outside.
Dissolving uric acid stones
Uric acid stones are the only stones that can sometimes be dissolved with medication. Alkalicitrates or sodium carbonate, sometimes allopurinol, can be used. Alkalicitrates and sodium carbonate increase the pH value of the urine, allopurinol lowers the uric acid level. Drinking a lot supports the effect of the medication: If more urine is formed, uric acid can dissolve better. In the case of a urinary tract infection, it is not possible to treat uric acid stones with medication.
If the treatment is successful, it saves the need for an operation to remove the stones. However, it is unclear how often uric acid stones can be dissolved with medication. So far, there have been no sufficiently conclusive studies.
How are kidney and ureter stones removed?
If stones are not excreted on their own, they are either shattered with shock waves or removed during a small operation. Which method is best depends mainly on the size, location and composition of the stones.
Shock wave therapy
In shock wave therapy, the stones are shattered by sound waves. The debris then goes off with the urine. The treatment is also called extracorporeal shock wave lithotripsy (ESWL). A sound probe is placed on the skin and sends sound waves through the tissue to the stones. In the case of uncomplicated kidney stones, shock wave therapy takes about 30 to 60 minutes. It is often possible on an outpatient basis. The success of the treatment is checked with an ultrasound or X-ray.
Shock wave therapy is particularly appropriate for kidney stones smaller than 20 millimetres. However, if the stones are located in the upper third of the ureter, they should not be larger than 10 millimetres.
Removal with an endoscopic procedure
When urinary stones are removed by surgery, two methods are commonly used: uretero-renoscopy (URS) and percutaneous nephrolithotripsy (PCNL).
Uretero-renoscopy (URS): This method uses an endoscope to guide fine instruments through the urethra and bladder up into the ureter and up to the stone. There the stone is crushed mechanically or by laser so that the debris can be excreted or removed endoscopically. The URS is used for urinary stones that are larger than 10 millimeters and lie in the middle or lower third of the ureter. Kidney stones up to 20 millimetres in diameter are also frequently removed by URS.
Percutaneous nephrolithotripsy (PCNL): In this method, the endoscope is inserted into the renal pelvis or kidney through a small incision in the back. There the stones are also crushed mechanically or by laser and then removed with small forceps. This method is mainly used for kidney stones with a diameter of 10 millimetres or more.
Both methods require a general anaesthetic and a short hospital stay.
Today, a major operation is rarely necessary for the removal of kidney stones.
What are the advantages and disadvantages of the different treatments?
In the case of kidney and ureter stones, different treatments are possible depending on the situation. Studies have so far only compared the following treatments.
Shock wave therapy and percutaneous nephrolithotripsy (PCNL) for kidney stones
Some small studies have tested the shock wave therapy and the PCNL. In comparison, endoscopic surgery was more successful than shock wave therapy. Three months after the treatment it turned out:
After shock wave therapy, 44 out of 100 people were free of kidney stones.
After PCNL, 95 out of 100 people were free of kidney stones.
However, the chances of success of shock wave therapy also depend on the size, position and composition of the kidney stones: stones with a diameter of less than 10 millimeters are easier to shatter. This is less often the case with larger or harder stones. Stones in the lower part of the kidney can also be treated less well with shock wave therapy.
Shock wave therapy involves the risk that the stone debris remains too large and gets stuck in the ureter on its way to the bladder. Then further treatment is necessary. Sometimes a small tube (a so-called ureteral splint) is inserted into the ureter as a preventive measure. It should ensure that the stone remains can flow off well.
The shock waves can be painful. Therefore one receives painkillers before the treatment. The kidney tissue can also be injured, which can lead to bleeding, for example. However, serious complications and long-term consequential damage are rare.
Percutaneous nephrolithotripsy can also lead to bleeding. This can sometimes require a blood transfusion. Fever and wound infections can also occur after the operation. Other organs can also rarely be injured. A hospital stay of several days is also necessary.
Since there are only a few small studies comparing these two treatments, the frequency of complications cannot be quantified well. However, shock wave therapy is generally considered the gentler treatment.
Shock wave therapy and ureterorenoscopy (URS) for ureteral stones
When kidney stones have migrated into the ureter, we speak of ureter stones. These stones are usually treated with shock wave therapy or endoscopically via the bladder and ureter. Several studies have compared the success rates of these methods with ureter stones. It has been shown that most stones can be successfully treated with shock wave therapy. In ureterorenoscopy, however, the success rate is somewhat higher:
78 out of 100 people were free of ureteral stones after shock wave therapy.
93 out of 100 people were free of ureteral stones after endoscopic treatment.
After shock wave therapy, a second intervention is more often necessary.
The advantage of shock wave therapy is that it leads to complications less frequently than URS: Complications occurred after 19 out of 100 endoscopic procedures, but only after 10 out of 100 shock wave therapies.
Possible complications of ureterorenoscopy are bleeding and urinary tract infections. The urethra can also be injured. However, serious complications are rare overall.
Supporting treatments such as a ureter splint or a temporary artificial renal outlet were also much less necessary after shock wave therapy. However, pain occurred more frequently during and after the treatment. In addition, postoperative bleeding and infections seem to occur more frequently after shock wave therapy.