Against the background of the development of urolithiasis, calculi form in the kidneys of a person. They can have not only different origins, but also composition. To determine these characteristics, an analysis of kidney stones is performed. Based on the results of the study, the doctor can judge the reasons for the formation of calculi, as well as draw up the most effective treatment regimen.
Types of Kidney Stones
The formation of dense formations is in most cases a lengthy process. In some it is faster, in others it is slower. In any case, the composition of all stones is represented by a mixture of minerals and organic substances.
Types of kidney stones:
- Phosphates and oxalates. Their basis is calcium salts. These calculi are considered the most common. They are found in most patients suffering from urolithiasis.
- Urata. These are calculi, the formation of which is a consequence of an excess of uric acid in the body. In addition, they can form against the background of the pathology of the digestive system.
- Cystines and xanthines. These types of stones are rarely diagnosed. The reason for their formation is anomalies in the development of the urinary system. In its pure form, cystine and xanthine are practically not found. As a rule, they contain various impurities.
- Phosphate-ammonium-magnesium stones and struvite. The reason for their formation is a long course of the infection process in the body.
Stones are classified by many other parameters. For the analysis of kidney stones, the following indicators are clinically significant: size, shape, quantity and localization.
Indications for the study
It is prescribed when the patient has urolithiasis. With the help of the analysis, the doctor can determine the cause of the pathology and draw up the most effective therapeutic scheme. Evaluation of the structure of calculi also allows you to assess the state of human health in general.
Do I need training?
An analysis of the composition of kidney stones is a study that is conducted on biological material obtained from the human body. The amount of substances in the stones does not change if a person does not observe the daily regimen and diet. Thus, before the study is not required to carry out any preparatory measures.
Obtaining biological material
Before donating kidney stones for analysis, they must be removed from the body. In order to get a sample for research after surgery, it is enough to inform the doctor about your desire. After the operation, the patient can freely return calculi extracted from the kidneys.
Sometimes the stones leave the body in an independent way along with the flow of urine. As a rule, very small calculi are excreted with urine, or those that in the recent past were subjected to crushing using modern medical techniques.
During urination, it is necessary to pass the stream through a dense, but thin tissue. You can also purchase a special filter at the pharmacy for this purpose. After completion of the act, the fabric must be carefully examined. Sometimes the size of the stones is so small that outwardly they look like tiny grains of sand.
The resulting sample must be dried on a cloth or filter. After that, it must be delivered to the laboratory or taken to the attending physician.
Instructions for the preparation of biomaterial
In order for the analysis of kidney stones to be as reliable and informative as possible, certain rules must first be observed.
Preparation of biomaterial consists of the following steps:
- After receiving the samples, rinse them with cold clean water (drinking can also be used).
- Then the stones must be placed on a cloth or filter and thoroughly dried.
- After this, the stones should be placed in a container with a tightly screwed lid. This medical product can be purchased both in the pharmacy and directly in the laboratory.
- The container must be signed. It is important to clearly indicate the name and surname of the patient, as well as the year of his birth. Some institutions have additional labeling guidelines. For example, in the famous Invitro laboratory there is the following requirement: if the linear size of the calculus is less than 1 mm, the word “micro” must be added on the container.
- The product with the sample should be placed where exposure to sunlight is excluded. He should be there constantly until he is sent to the laboratory.
Analysis of kidney stones is carried out only if the linear dimensions of calculi in 3 dimensions are more than 0.1 mm. Samples must be delivered to a medical facility within six months of their removal from the body.
Basic research methods
In most cases, classical laboratories do not perform chemical analysis of kidney stones. They send biological material to specialized medical institutions (pathological anatomical bureaus and research institutes).
Regarding which kidney stone tests are currently underway:
- Spectroscopy. In most cases, multi-structural calculi are the biological material. The essence of the method is the effect of infrared radiation on the stones, after which the degree of its light absorption is evaluated.
- Thermogravimetry. This study, during which the sample is exposed to various temperatures. After this, its changes in weight are fixed. This method is very expensive, because of the high cost it is carried out less often than others.
- Dry and wet chemistry. Before the analysis, ashing of the sample (its mineralization) is carried out. After that, the structure of the calculus is evaluated by the method of dry chemistry. To do this, the formation is maximally crushed and dried on a sheet of paper. Using this method, the structure of the nucleus, its consistency and heterogeneity are investigated.
- Chromatography During this study, the absorption capacity of the constituent substances, into which the calculus is previously divided, is analyzed.
- Neutron activation analysis. The essence of the method is neutron bombardment of the calculus, due to which the smallest inclusions can be detected in it.
- Determination of porosity. This is a characteristic by which it is easy to determine the type of stone. But carrying out only this method is impractical if the calculus has a mixed structure. In such cases, the method is combined with chromatography.
- Polarization microscopy. A light beam is directed to the calculus in different planes. After that, the nature of the reflected rays is evaluated. Each type of stone has a specific polarization index. Due to this, the structure of the calculus is easily determined.
In all cases, microscopy of urine sediment is also carried out, its acidity indicator is evaluated, bacteriological culture is carried out. In the process of chemical analysis of urinary stone, a cystine test is additionally made from the kidneys.
Indirect Analysis Methods
If it is impossible to obtain biological material, an X-ray examination is indicated. At the same time, you can take pictures not only in the laboratory.
The easiest way to detect oxalates and urates. These types of calculi contain uric and oxalic acid. Due to this, they are well visualized on an x-ray image. If calcium ions are present in the stones, the stones will also be clearly visible.
It is necessary to know that the staff of the radiology department cannot evaluate the chemical composition of the formation from the picture. To this end, a survey urography is shown. Using this method, it is possible to determine the structure of the stone, evaluate its shape, contours, as well as the configuration of the urinary ducts.
Interpretation of Results
The foundations of most calculi are: calcium oxalate, cystine, tripelfosphate and uric acid. The sizes of the stones may vary depending on their location. Some calculi grow to the size of the kidney itself.
If the stone contains calcium, the following pathological conditions may be the cause of its formation:
- Gout. In such cases, uric acid will also be present in the calculus. Less commonly, sodium and ammonium salt are found in the composition.
- Hyperparathyroidism.
- Osteoporosis.
In most cases, the nucleus of kidney stones consists of oxalate and calcium. Its outer part is represented by a struvite layer. The latter may contain about 6 dozen different compounds and the inclusion of pathogenic microorganisms. According to statistics, calcium stones are diagnosed in 85% of patients. As a rule, the formation of other types of calculi is associated with genetic defects or the vital activity of infectious agents.
Where to do
Analysis of kidney stones is not carried out in classical medical institutions. The patient can deliver the biological material to the laboratory, the staff of which will send it for analysis to the research institute or pathological office.
State polyclinics also study the chemical composition of calculi extracted from the kidneys. Stones can be sent to specialized laboratories immediately after surgery. As a rule, an assessment of the chemical composition of stones is necessary if the doctor has not decided on further treatment tactics.
Regarding the availability of services in private clinics, you need to be interested directly in the registry of the selected institution.
Cost and reviews
The price of analysis of kidney stones depends on the complexity and volume of the procedure. The average cost of quantitative spectroscopy in the capital varies between 2300 - 2500 rubles. The polarization microscopy method is the most affordable. Its minimum cost is 400 rubles.
The price of a comprehensive analysis of kidney stones in Moscow depends on the policy of the medical institution. In the clinic "Medicine" the cost of the study is 1800 rubles. The highest price was recorded at the Petrovskiy Mall. She is 4,000 rubles. The minimum cost revealed in the clinic Artis - 1000 rubles.
According to patient reviews, the price of the study is fully justified. This is due to the fact that, based on the results of the analysis, the doctor is guaranteed to determine the root cause of the formation of deposits and to make a really effective treatment regimen for the underlying ailment. Judging by the medical reviews, the study not only helps to correctly develop a treatment plan, but also significantly reduces the risk of relapses in the future.
Finally
The course of urolithiasis is accompanied by the formation of calculi. They can have a different structure, size, shape and consistency. After surgery, each patient has the right to take the extracted deposits and make an analysis of kidney stones. Also, such an initiative often comes from the attending physician. Based on the results of the studies, a specialist can determine the true cause of the development of urolithiasis and draw up the most effective therapeutic regimen. In addition, by assessing the chemical composition of the calculus, the doctor is given the opportunity to make adjustments to the previously prescribed treatment.