Urolithiasis

Urinary calculi (Latin: uroliths ) are abnormal fixed structure ( calculus ) that may arise in the urinary tract, ie in the kidneys (kidney stones), the ureter ( ureteral stones, ureter ), in the urinary bladder ( bladder stones ) or in the urethra.

Formation

Causes

Urinary stones can occur for various reasons, for example due to an inflammation of the kidneys or urinary tract, due to a too narrow urethra, as a result of gout and diabetes or by eating an excessive amount of oxalic acid in certain foods. Furthermore, congenital metabolic disorders such as Crohn's disease or cystinuria one can lead to stone formation.

Development

Urinary stones can arise when mineral salts are precipitated, which are normally dissolved in the urine, such as calcium carbonate, calcium phosphate and calcium oxalate. With a sufficiently large acidity of urine, small crystals ( "bubble meal" ) can first form, which gradually merge to form larger structures. In extreme cases, the entire renal pelvis can be filled through these hard deposits ( " discharge block ").

Chemical composition and designation

As often mineralogists were consulted in the past for the analysis of urinary calculi, has prevailed in many types of stone to this day the mineralogical against the chemical name. We distinguish the following urinary stones:

• Whewellite ( calcium oxalate monohydrate )
• Weddellit ( calcium oxalate dihydrate )
• Carbonate apatite ( Dahlit, -carbonate hydroxyapatite)
• Brushite ( calcium hydrogen phosphate dihydrate )
• Struvite ( magnesium ammonium phosphate hexahydrate)
• Urate (salts of uric acid)
• Cystine
• Xanthine ( 2.6 Dihydroxypurin )

Clinical picture

Urinary stones often remain unnoticed for a long time and are only noticeable when they (usually under extremely strong, spasmodic pain ( colic ) ) in the renal pelvis or the ureter jam.

Urinary stones of calcium salts can be detected by ultrasound by X-ray, urinary stones from uric acid ( " Uratsteine ​​").

Treatment

As treatment of colic pain and antispasmodic drugs are given, which is sufficient in most cases ( about 80 % ) for a disposal of, or stones. If not, the stones must be either surgically removed or disintegrated by shock wave destruction ( Extracorporeal Shock Wave Lithotripsy ) so that it is disposed of independently. The shock waves are so focused from outside the body to the stone that he shatters into small fragments.

The sole drinking large quantities to the " expulsion " of the stones, without additional analgesic and anticonvulsant treatment is an outdated misconception holds up today even with some specialists still persistent.

The removal of urinary stones was to the 19th century, a profession in which the Lithotomus.

Prevention

As prevention against newly occurring symptoms ( metaphylaxis ) drinking plenty of large quantities of liquid ( at least two liters per day) is recommended and the waiver of certain foods: When calcium-containing stones on dairy products in oxalate, for example on rhubarb and uric acid stones on purine-rich foods such as z. B. giblets, liver and blood sausage.

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

Urinary stones in domestic dogs

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

In domestic dogs struvite stones dominate, accounting for some 50 % of all urinary stones from, where their share has fallen slightly by dietary measures in the last 20 years. Since the early 1980s, the proportion of calcium oxalate stones continues to increase, their share is in current clinical trials with approximately 30%. Ammonium urate stones make up about 10%, they are due to a genetic defect heaped before Dalmatians. Cystine stones account for about 5%.