Kidney stones and ureteral stones

Kidney stones and ureteral stones are very common. In Germany, the incidence of kidney stones is 4-5%, making it a widespread disease. Affected patients usually show acute pain as a symptom. The stones may also be discovered by chance in an unrelated ultrasound or computer tomography (CT scan). Kidney stones can be treated through surgery in which the stones are crushed and removed. They can also be treated with medication. There is a high risk of recurrence, up to 50%, though this can be reduced by changing dietary habits and certain lifestyle habits, among other things. Treatment of urinary stones is in the hands of an experienced urologist.

Questions about the diagnosis and treatment of kidney stones

The development of kidney stones depends on the specific type of stone. According to current scientific knowledge, the most common kidney stones, calcium oxalate stones, form due to microscopic changes in the kidney tissue. Smallest crystals are formed, which are fixed to the kidney tissue and grow over time into larger kidney stones through the accumulation of further crystals. If these deposits detach from the kidney tissue, a renal calculus is present. If this stone moves into the ureter, it is referred to as a ureteral stone. Other types of kidney stones are caused by changes in the pH value of the urine (uric acid stones) or due to infections (infectious stones). An additional, rare type of stone, cystine stones, have hereditary causes.

The type of treatment depends on the size, location, and composition of the kidney stone. Options range from a simple urinary diversion by means of a ureteral splint, external kidney stone disintegration by shock waves, ureteroscopy stone treatment (URS- Ureterorenoscopy), or a puncture from the outside (Mini-PCNL), to surgery. Nowadays, stone removal is mainly done by minimally invasive procedures such as ureterorenoscopy or mini-PCNL.

Normally, urine flows unhindered from the kidney through the ureter into the bladder. If there is a stone in the kidney, the flow of urine into the ureter is not interrupted. However, if a stone slips from the kidney into the ureter, urine backs up and the wall of the ureter and renal pelvis is stretched. This stretching, known as renal colic, is very painful. Depending on the level of urinary obstruction, the pain is felt in the side (flank), lower abdomen, or genitals.

Strong, colicky pain in the side (flank) area often leads to a visit to the doctor. In any case, a doctor or hospital should be consulted if the pain is accompanied by a fever. Kidney stones are also detected during general urological screening examinations.

The composition of kidney stones is varied. The most common stones are made of calcium oxalate or uric acid. Infectious stones vary as well, such as magnesium-ammonium-phosphate stones. Additionally, there are stones caused by genetic metabolic changes, such as cystine stones. The term “small calcifications” does not refer to a specific kidney stone composition but describes an accumulation of tiny crystals in the kidney that are considered to be able to pass spontaneously.

Kidney stones are completely unrelated to gallstones, and even the formation is different.

A basic measure to prevent kidney stones is dietary changes, which applies to nearly everyone. General recommendations include: increasing fluid intake to about 2 litres a day, reducing meat consumption, increasing the consumption of diluted citrus-containing fruit juices (such as orange and lemon juice), and drinking bicarbonate-rich mineral water (HCO3 -> 15000 mg/l). Under no circumstances is a low-calcium diet recommended.