Ureteral stones are kidney stones that have moved down into the ureter.
The stone begins as a tiny grain of undissolved material located where urine collects in the kidney. When the urine flows out of the kidney, this grain of undissolved material is left behind. The material deposited is usually a mineral called calcium oxalate. Over time, more undissolved material is deposited, and the stone becomes larger. Most stones enter the ureter when they are still small enough to move down into the bladder. From there, they pass out of the body with urination. Some stones, however, have grown larger by the time they leave the kidney. They may become lodged in a narrow part of the ureter, causing pain and possibly blocking the flow of urine.
How are ureteral stones diagnosed?
Usually the only symptom of a stone is extreme pain. Stones are found on an x-ray or sonogram. These diagnostic images provide urologists with valuable information about the stone’s size and location. If your doctor suspects a stone but is unable to make a diagnosis from a simple x-ray, he or she may scan the urinary system using a procedure called an intravenous pyelogram (IVP). Since an IVP requires preparation, it has been replaced in many hospitals by an abdominal/pelvic CT scan, an extremely accurate diagnostic tool that can detect almost all types of ureteral stones.
What are the treatment options?
Treating ureteral stone disease depends on the size, position and number of stones in your system. Fortunately, the majority of small stones (0.2 inch or 4 mm in diameter) that are not causing infection, blockage or symptoms will pass if you drink plenty of fluids each day. The sudden pain that occurs when small stones start down the ureter can usually be treated with rest and analgesics or painkillers. Surgery should be reserved for cases where all other approaches have failed.
Surgery may be needed if a stone:
- does not pass after a reasonable period of time and causes constant pain
- is too large to pass on its own
- blocks the flow of urine
- is associated with ongoing urinary tract infection
- damages kidney tissue or causes constant bleeding
- has grown larger (as seen on follow-up x-rays)
- is solitary
In the past, surgery to remove a urethral stone was very painful and required a lengthy recovery time (four to six weeks). Today, treatment is greatly improved, and most options require only minor outpatient procedures to break the stones into small pieces so they can either be removed or pass on their own.