What are the symptoms of ureteral stones? Can they be removed through medication?

Author: Zhang Yi, Chief Physician, Peking University International Hospital

Reviewer: Han Sujun, deputy chief physician, Cancer Hospital, Chinese Academy of Medical Sciences

Ureteral stones are mostly the name for kidney stones that are discharged into the ureter. A very small number of stones are spontaneously generated in the ureter (primary stones).

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Ureteral stones and kidney stones can sometimes transform into each other. For example, a kidney stone may become a ureteral stone just after it falls into the ureter, but it may return to the kidney due to changes in body position, and the ureteral stone may turn back into a kidney stone.

Ureteral stones and kidney stones are collectively referred to as upper urinary tract stones, and their incidence is relatively high.

1. What are the factors that cause ureteral stones?

In fact, this question should refer to the cause of kidney stones. At present, the more consistent view is that multiple factors affect the body's internal metabolism or urinary tract structure. Simply put, there are three major factors: epidemiological factors, urine factors, and urinary tract factors.

Epidemiological factors come from surveys. For example, ureteral stones are very different in the north and south, with the incidence rate in the south being higher than in the north. In addition, men are more likely to be infected than women.

Urine factors: urine contains more components that produce crystals and fewer components that resist crystallization. Drinking less water can increase urine concentration. In addition, changes in urine pH also affect stone formation.

Urinary tract factors, such as ureteral obstruction, urine deposition above the obstruction site, forming stones.

2. What are the symptoms of ureteral stones?

"Kidney stones are like melons planted in the kidneys, but the ureters are unlucky." In the early stages of kidney stone formation, there may be no symptoms, or a little blood in the urine (red blood cells are found in the urine routine test). As the stones grow larger or suddenly fall off into the ureters, the hard and irregular shape stimulates ureteral spasms, which can cause obvious and severe waist and abdominal pain. The pain is usually paroxysmal and often accompanied by nausea and vomiting. It can radiate to the perineum and thigh roots, which is a characteristic of colic.

If ureteral stones can be discharged with urine, there is no problem. If the stones are large or cause ureteral obstruction, the stones are stuck here and cannot be discharged, which can also cause hydronephrosis on one side. Hydronephrosis will aggravate low back pain and lead to kidney damage if not treated.

In addition, stones can also cause scratches and inflammation, leading to ureteral stenosis. If combined with or triggering complications such as infection, it can also affect the whole body.

If the above symptoms occur and ureteral stones are suspected, first do a routine urine test to see if there are red blood cells. Then do a B-ultrasound or abdominal plain film to see if there is hydronephrosis. Ureteral stones can sometimes be found directly. If it is still unclear, a CT scan can be performed.

To diagnose ureteral stones, it is necessary to determine the number, size, and location of the stones, and also to determine whether the stones have caused renal damage on the corresponding side.

3. What are the treatments for ureteral stones?

Ureteral stones can be treated conservatively or surgically.

Conservative treatment, such as stone removal with drugs and antispasmodics to dilate the ureters; diuretics combined with drinking water to increase urine production; exercise is also a method of conservative treatment; anti-infection treatment, these methods combined may flush the stones out.

Generally, upper urinary tract stones smaller than 0.6 cm have a chance to be discharged from the renal pelvis and ureter on their own. For stones larger than 0.7 cm, the possibility of being discharged on their own is small, and conservative treatment will not be the first choice. Instead, surgical methods should be considered, such as extracorporeal shock wave lithotripsy, ureteroscopic lithotripsy and minimally invasive surgical stone removal.

Extracorporeal shock wave lithotripsy uses the energy of shock waves to concentrate on the stones and break them into pieces, turning large stones into small fragments, such as splitting one into two, then into four, or into more pieces, and combines it with stone removal treatment to expel the stones.

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For more complicated stones, various laparoscopy methods are required. For example, large stones in the upper ureter can be crushed with a percutaneous nephrolithotomy and flushed out or sucked out. For stones in the middle and lower ureter, a ureteroscope can be used to reach the stone site through the urethra, bladder, and ureter, and the stone can be crushed with a holmium laser or pneumatic ballistics. If the stone drifts back to the kidney during the lithotripsy process, there are special soft endoscopes to continue the lithotripsy and stone removal.

If the stone is very large and in the middle, and cannot be reached from above or below, laparoscopic minimally invasive surgery can be used to remove the stone.

Therefore, the specific treatment method for ureteral stones should be selected based on the size, location, and number of the stones, the patient's physical condition and age, and whether there are concurrent kidney stones.