Urinary stone

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Classification according to ICD-10
N20 Kidney and ureteral stones
N21 Stone in the lower urinary tract
ICD-10 online (WHO version 2019)
X-ray image of a bladder stone

Urinary stones ( Latin : uroliths ) are crystalline deposits ( concrements ) of the lower urinary tract of various compositions and sizes that are formed from the urine . This must be distinguished from calcifications of the functional kidney tissue, e.g. B. in nephrocalcinosis that lie outside the hollow system. Depending on where they were found, a distinction is made between kidney stones (located in the renal pelvis or the kidney calyx), ureteral stones (located in the upper, middle or lower ureter ), bladder stones (located in the urinary bladder ) or urethral stones of the urethra . The disease is called stone disease , stone disease and urolithiasis referred.

Emergence

causes

Urinary stones can develop for a variety of reasons, for example as a result of inflammation of the kidneys or the lower urinary tract, due to a too narrow urethra , as a result of gout and diabetes or from consuming excessive amounts of oxalic acid in certain foods. Congenital metabolic disorders such as cystinuria or Crohn's disease can also lead to stone formation.

development

Urinary stones can develop when mineral salts are precipitated that are normally dissolved in the urine , such as calcium carbonate , calcium phosphate and calcium oxalate . If the acid content of the urine is sufficiently high , small crystals (bladder grit, urine grit) can initially form, which gradually combine to form larger structures. In extreme cases, the entire renal pelvis can be filled with these hard deposits (pouring stone).

Chemical composition and naming

Since in the past mineralogists were often used to analyze urinary stones, the mineralogical name has prevailed over the chemical name for many types of stone. The following urinary stones are distinguished:

Clinical picture

Urinary stones often go unnoticed for a long time and only become noticeable when they become jammed in the renal pelvis or ureter (usually with extremely severe, cramp-like pain ( colic )).

Urinary stones made from calcium salts can be detected by X-rays , urinary stones made from uric acid (urate stones) by ultrasound .

treatment

Pain-relieving medication is given to treat colic, which in most cases (around 80%) is sufficient to remove the stone (s). If not, the stones must either be surgically removed or crushed by shock wave destruction ( extracorporeal shock wave lithotripsy ) so that they come off on their own. The shock waves are focused on the stone from outside the body in such a way that it breaks into small fragments.

Drinking large amounts alone to expel the stones without additional drug treatment is not promising. The spontaneous loss of small ureteral stones can be facilitated by medication such as alpha blockers (e.g. tamsulosin ) or nifedipine . However, this is an off-label use . The surgical removal of bladder stones was an independent profession until the 19th century, that of the lithotomus .

prevention

As a prevention against recurring complaints ( metaphylaxis ), it is recommended to drink sufficiently large amounts of fluids (at least two liters per day) and to avoid certain foods: for calcium-containing stones on dairy products, for oxalate stones for example on rhubarb and for uric acid stones on foods rich in purine such as z. B. offal, liver and blood sausage.

Furthermore, citrate (citric acid) reduces the risk of the formation of urinary stones. The citrate excreted in the urine comes on the one hand from the metabolism, especially the citric acid cycle , on the other hand it is absorbed with food.

Urinary stones in domestic dogs

  • Bladder stones in dogs, surgical site

  • Ultrasound image of a urinary stone in the prostate part of the urethra in a dog. (Ur = urethra (urethra), Pr = prostate , St = urinary stone)

In domestic dogs , struvite stones dominate , they make up about 50% of all urinary stones, although their share has decreased slightly due to dietary measures in the last 20 years. The proportion of calcium oxalate stones has been rising continuously since the early 1980s, and current studies have shown that their proportion is around 30%. Ammonium urate stones make up about 10%, and due to a genetic defect, they occur more frequently in Dalmatians . Cystine stones make up about 5%. Diets that acidify and thus dissolve stones can often be used to treat struvite stones. In veterinary medicine, larger stones are mainly removed surgically by opening the abdominal wall and urinary bladder. The laser lithotripsy requires a high equipment and safety effort and is therefore only available in a few veterinary clinics. The Pneumolithotripsie under endoscopic control can be considered.

literature

  • S2k guideline urolithiasis: diagnostics, therapy and metaphylaxis of the German Society for Urology (DGU). In: AWMF online (as of 2015)
  • Joachim Frey : Clinic for diseases of the urinary tract. In: Ludwig Heilmeyer (ed.): Textbook of internal medicine. Springer-Verlag, Berlin / Göttingen / Heidelberg 1955; 2nd edition ibid. 1961, pp. 978–990, here: pp. 983–988 ( stone diseases ).
  • Albrecht Hesse, Dietmar Bach: urinary stones - pathobiochemistry and clinical-chemical diagnostics . (= Clinical chemistry in individual representations . Volume 5). Thieme, Stuttgart 1982, ISBN 3-13-488701-0 .
  • Albrecht Hesse, Andrea Jahnen, Klaus Klocke: Aftercare for urinary stone patients. A guide for medical practice . Urban & Fischer, 2002, ISBN 3-334-60832-8 .
  • Rolf Klemmt: Wilhelm von Lack's “Art of the Bladder Stone” and a few other recipes against urinary disorders by unknown authors from the Middle Ages. In: Sudhoffs Archiv 49, 1965, pp. 129–146.
  • Stefan C. Müller et al .: Epidemiology, Instrumental Therapy and Metaphylaxis of Urinary Stone Disease. In: Deutsches Ärzteblatt . Volume 101, No. 19, 2004, pp. A1331-A1336.
  • C. Schmaderer, M. Straub, K. Stock, U. Heemann: Urinary stone diseases, treatment and metaphylaxis. In: Nephrologist. 2010, 5, pp. 425-438.

Web links

Individual evidence

  1. ↑ A. Hesse: Urolithiasis in rabbits. The origin of the names. In: Animal Stone Letter. 7: 1/2013.
  2. ↑ uroliths in dogs. Retrieved February 28, 2020 .
  3. ↑ A. Hesse: Urinary stone composition in dogs in the course of 1979-2007. In: Animal Stone Letter. 1/2009. Urinary Stone Analysis Center Bonn.
  4. ↑ Peter Pantke and Klaus Flaig: Intracorporeal fragmentation of uroliths with a pneumatic lithotripter (StoneBreaker). In: Kleintierpraxis Volume 62, 2017, Issue 1, pp. 4-14.