Kidney stone

Kidney stones or Nephrolithen ( gr νεφρός nephros, kidney ' and λίθος líthos ' stone' ) are deposits ( urinary stones ) in the kidneys or urinary passages and corridors are also known as ureter and bladder stones. Other names are Nierenkonkrement or renal calculus. A collection of many small kidney stones is also called renal gravel. The medical term for kidney stones is nephrolithiasis.

• 7.1 Herbalists

Frequency

The disease incidence of kidney stones is in Central and Western Europe, five per cent. The ratio of affected men to women is 7 to 5 Most commonly, the disease between 30 and 50 years of age occurs. In industrialized countries, 20 % of men and 7% of women living with an increased risk of stone. Is this a kidney stone occurred, the risk of recurrence ( recurrence ) is 60 %.

Classification

Most common is the classification of kidney stones by their outward appearance or their chemical composition:

• Classification according to shape: valve stones
• Stag Stones
• Coral stones

• Classification according to chemical composition: Calcium oxalate stones ( 65%)
• Urate stones ( uric acid stones, 15 %)
• Magnesium ammonium phosphate stones ( struvite stones, 11 %) occur mainly in connection with infections and are therefore also called infection stones.
• Calcium phosphate blocks ( 9%)
• Cystine (ca. 1%)
• Xanthine stones (1 %)

Causes

The formation of kidney stones depends on many factors that lead depending on the extent to different composite concretions. Many metabolic processes are still unclear in this context. At the molecular level, there is an increase in the concentration of sparingly soluble compounds or ions other urinary components to exceed the so-called solubility product. Thus, these substances begin to fail (salts ) and to form conglomerates, the urinary tract can no longer pass a certain size.

The increase in the stone-forming ( lithogenic ) urine components can have many causes. In addition to dehydration (dehydration ) and dehydration diseases come here in question, leading to an increased urinary concentration of metabolites or ions, such as hyperparathyroidism, hyperoxaluria, hyperuricemia (increased uric acid, gout ), or certain infectious diseases. An abundant supply of purines through diet can increase uric acid levels. There are also disorders of renal function, in which too much calcium phosphate is excreted ( Tubular Acidosis ). Anatomical peculiarities of the kidney Harnleitersystems as horseshoe kidney and ectopic ureter and Abstrombehinderungen promote stone formation.

In kidney stones increased by a gastric bypass surgery suggests a study with 24 patients whose oxalate excretion was measured before and after the surgery. Previously, she was daily at 31 mg, then 41 mg. The relative saturation of urine with calcium oxalate was significantly increased (1.73 before bypass surgery versus 3.5 after). Every fourth patient was a hyperoxaluria with Exkretionswerten of 63 mg per day. Prior to surgery, no patient had an increased risk of kidney stones.

Symptoms

Hiking stones in the ureter, a, they can clamp at the constrictions. The cramping muscle contraction leads to strong wave-like pain in the flank ( renal colic ). In general, blood is visible or biochemically detectable in the urine. It usually comes to a urine storage and the affected kidney can be damaged. It threatens pyelitis ( pyelonephritis ) to uremia. Small stones (maximum diameter up to 6 mm ) can also happen without special complaints.

Diagnostics

• Physical examination
• Examination of the urine (preferably on traces of blood = hematuria)
• Ultrasound, with smaller stones can be easy to overlook this
• X-ray contrast imaging of the kidney and urinary tract (so-called i - v. pyelogram ), not suitable for the representation of urate and xanthine stones as well as the rare indinavir stones
• CT also shows the so-called non shaded by concretions, which are not seen in conventional radiographs
• MRI
• Retrograde contrast media presentation of urinary tract
• Endoscopic procedures

Most often, the ultrasound examination, the urine test and the i v.- pyelogram be performed.

Therapy

Small kidney stones ( less than 6 mm ) have a good chance to create by itself the passage through the ureter to the bladder. Pure urate and cystine stones can often be resolved by alkalizing drugs ( Urolitholyse ). Other measures include:

Percutaneous nephrolithotomy (PNL )

This method is primarily used for larger stones, which cause pronounced Harnstauungen, used. Here, an endoscope is inserted through a small incision through which the stone is then smashed with shock waves.

Ureterorenoskopische stone removal (URS )

Such operational method is used with ureteral stones. A rigid but flexible, thin tube with an optical instrument is inserted further (similar to cystoscopy ) via the urethra into the bladder and the ureter. About the working channel of the optical instrument, different devices for destruction and removal of ureteral stones can be introduced. These may be ultrasonic, laser, special probes or clamps.

Loop extraction

Because of the high risk of injury it is now performed only in exceptional cases. About the urethra, a sling is introduced and the doctor tried to pull out the stone. The method is applied only when the stone in the lower third of the ureter. In the EU directives for Applied Medical will not be mentioned because of the risk of injury to the ureter.

Extracorporeal shock wave lithotripsy (ESWL )

Lithotripsy (from Greek λίθος 'stone' and τρίβειν, rub ') or ESWL is the shattering of urinary stones by shock waves. This can usually be dispensed with a stationary interference. In this method, an attempt is made with the help of bundled sound waves that are directed to the affected area without a percutaneous interface to crush the foreign body so far that it can be either naturally or surgically removed.

The treatment method was first time in 1980 by doctors at the University Hospital Grosshadern (Munich, Germany ), and engineers and technicians of the company Dornier System (Friedrichshafen, Germany ) carried out successfully (see Dornier lithotripter ). This plant is on display at the German Medical History Museum in Ingolstadt.

While the first devices ( see Figure 1 HM ) still had a water-filled tub in which the patient was, the newer devices now resemble a modern x-ray machine with only one sun. The patient lies on a movable table and is moved up to the coupling bellows or this to the patient. The consists of the shock wave generator with a water-filled silicone sleeve ( bladder ) and is slightly pressed against the patient's body to make good contact with the body. Do so, a hydrous gel is still placed between the surface of the Koppelbalges and skin to ensure a smooth passage of the shock wave. During the treatment, the unit automatically acquires the location of the stone and corrects the position of the patient, if the stone during shock wave treatment in the kidney shifts slightly. This ensures that the stone is always in the shock wave center and surrounding tissue is spared.

In this method, the patient does not require general anesthesia, as a rule only a mild analgesic is administered intravenously, the patient remains responsive. Against the noise resulting from the treatment ( approximately 3000 low-frequency impulses in 30 minutes), the patient receives hearing protection. Very often, this treatment can be performed on an outpatient basis. The exposure to the patient is low and by the targeted convergence of the shock waves less painful than the first type devices with a bathtub.

Also, for newer devices, in addition to X-ray cameras and ultrasonic devices for stone setting are used. Established methods for shock wave generation are electrohydraulic ( spark gap ), electromagnetic and piezoelectric generators. Today, more than 3000 devices ( lithotripters ) are used worldwide, about 90 % of all kidney stones are crushed in the industrialized countries in this way. In 2008 there were around 21,892 in Germany ESWL treatments.

Laser lithotripsy

The fragmentation of urinary stones has become possible through the development of flexible thin optical fibers with high damage threshold. In this case, a quartz optical fiber is inserted endoscopically under direct vision until shortly before the to -be-crushed stone., The transported by the fiber laser pulse of a flashlamp-pumped dye laser is now focused on the surface of a kidney stone, it is caused by the rapid evaporation of the surface material, a shock wave in the surrounding liquid that leads to a plurality of shots to the destruction of the stone. For the required laser power and the right choice of the wavelength at which the absorption of the stone material is maximum, depend on the chemical composition of the stone, which can vary. Therefore, it is useful to know its composition. This can be spectroscopically (see spectroscopy) to determine if, in less laser energy emitted from the irradiated stone fluorescent light is collected via a separate fiber and displayed on an optical multichannel analyzer. A downstream computer can then be determined from the spectral distribution of the fluorescence immediately the chemical composition. This was first demonstrated on kidney stones in a glass of water (in vitro) and then successfully tested on patients (in vivo).

Ureteral stent

In almost all of these applications while a catheter is often (even double-J catheter, stent or ureteral stent called ) left to expand and hold open the ureter for a few days or weeks in the ureter to facilitate the natural expulsion of another brick fragments. The catheter is rolled up at the top of the renal pelvis, at the lower end in the bladder for a few centimeters. The thus-formed double " curly tail " ( pigtail ) fixes the catheter in the ureter. The ureter is thereby also protected because the outgoing stone fragments are partially sharp edges and the walls of the ureter may be injured.

Prophylaxis

Had a patient for more than a kidney stone, it is more likely to form more stones. To prevent the formation of new blocks, it is important to find the cause of the formation. This is done by medically prescribed laboratory, blood and urine tests, including the medical history, the profession and eating behavior are included in the investigations. The stone should be analyzed according to its distance or its spontaneous voiding for its composition. To find the cause of stone formation, sometimes an examination of the urine collected over 24 hours in terms of volume, pH and the concentrations of calcium, sodium salts, uric acid, oxalate, citrate, and creatinine is performed by the doctor.

The simplest and most effective way to reduce the risk of the formation of blocks, is the dilution of the urine, by increasing the daily intake of liquid (water, tea). It should be 2.5 liters of urine are excreted daily.

Recent studies show that adequate amounts of calcium in the diet help (1000-1200 mg / day) in preventing the formation of oxalate stones. Calcium binds oxalate in the gut, through which it can be disposed of easily. People who tend to form such stones, the consumption of dairy products and other calcium-rich foods do not have to limit it. However, it is advised to avoid food with added vitamin D and calcium- based antacids.

As a protection against kidney stones has also been for many decades the alkalinizing potassium proven.

Persons with an acidic urine should be meat, fish and poultry because this kind of food contains high levels of purines to uric acid lowers too much their degradation urinary pH. An elevated uric acid levels may be a sign of an increased risk of stone formation, which must be treated with medication may.

People who have a tendency to formation of calcium oxalate stones should reduce following oxalatreiche food:

• Beet
• Chocolate
• Coffee
• Cola
• Rhubarb
• Spinach
• Strawberries
• Tea (black and green to less extent )
• Wheat bran

To prevent cystine stones, lots of water should be drunk, which reduces the cystine in the urine. To this end, each day more than three liters of water must be drunk, a third of them in the night.

Herbalists

It should be able to be brought kidney stones with the help of tea made ​​of genuine bedstraw for resolution. Just to assist in the removal of the stones, a tea made from dandelion roots. Genuine cat's whiskers or Orthosiphon relaxes the urinary Harngefäße, acts against the inflammation caused by kidney stones and decreased as total pain in the outgoing stones. Serology can be observed a decrease in the nitrogen levels in the serum. Even in ordinary inflammation of the kidney from carryover Blasenkatarrhe good results are possible.

Research News

The presence of the bacterium Oxalobacter formigenes in the intestinal tract can get the risk of kidney stones to reduce up to 70 percent. This says a study by a working group of the Boston University 's Slone Epidemiology Center. The Boston researchers indicate that the protective effect of the bacterium probably due to metabolism of oxalate in the digestive tract.