Calcinosis (calcification) is a common limited accumulation of calcium in the form of salts in the structure of various tissues, followed by a pathological change in their function. With satisfactory functioning of the organs of the digestive tract and urinary system, a normal metabolic exchange of calcium is provided in the form of its absorption in the small intestine and excretion with faeces and urine.
Mediated regulation of calcium metabolism is carried out by parathyroid glands by secretion of hormonal substances that enhance or inhibit the absorption and excretion of calcium, as well as the accumulation of its salts in the blood or bone tissue (calcification, hypercalcemia , osteoporosis ).
In a situation in which a generalized accumulation of calcium salts in one or another tissue is noted in a person due to general metabolic disturbances, specialists establish the conclusion of a "lime type metastasis". The formation of calcareous metastases is promoted by the increased leaching of calcium from bone tissue, which is observed in severe osteoporosis, fractures and malignant tumors of the bones, calcium salts accumulating in tissues that normally should not be.
When the limited accumulation of calcium in any part of healthy tissue is not caused by systemic disturbances in mineral metabolism, it is necessary to assume the presence of calcification of the dystrophic type. Not necessarily, even pronounced calcinosis means an aggravation of the patient's health, for example, with tuberculosis lesions, the appearance of signs of calcification indicates a transition to the period of convalescence.
Causes of calcification
At the heart of the pathogenetic mechanism of calcification of any localization is the transition of calcium from the soluble liquid state to the excessive accumulation of its salts in the tissues of the human body. This pathological condition can develop as a result of a variety of provoking factors, but the trigger mechanism for the development of calcification is the failure of calcium metabolic processes in the body.
Most often, the exchange of calcium is disrupted as a result of an incorrect function of the regulatory hormonal substances produced by the parathyroid glands that arise with various endocrinopathies. In addition, the process of absorption and utilization of calcium salts is affected by the level of calcium in the blood, which can vary significantly both in the direction of increase and a sharp decrease. In the process of metabolic transformations of calcium, an enormous number of enzymes take part, so if a person has fermentopathy, conditions are created for excessive accumulation of his salts in the body.
There are different categories of provoking factors that affect the development of signs of calcification, which can be divided into exogenous and endogenous. Exogenous causes of calcification include various types of trauma to bones and soft tissues, as well as excessive intake of vitamin D in the human body, which occurs when the dosage is not met in pediatrics. Endogenous are internal pathological conditions of the human body, accompanied by systemic metabolic disturbances not only of calcium, but also of other minerals (polycystosis, nephropathies, myeloma , malignant neoplasms, endocrinopathies).
A good substratum for excessive accumulation of calcium is connective scar tissue, so any pathological changes in the organs, accompanied by proliferation of fibrous tissue, sooner or later provoke calcification (valvular heart disease , atherosclerotic vascular changes, grafts).
Symptoms and signs of calcification
Pathological calcification or calcification can manifest itself in the combined damage of several groups of tissues and organs of the human body or limitedly affect one or another structure. Each of the forms of calcification has specific clinical and laboratory-instrumental features, therefore one should consider the variants of the course of this pathology according to the localization of pathological changes.
As a secondary localization of the process of calcification, calcification of the skin is considered, since its formation is facilitated by the preliminary accumulation of calcium in the parenchyma of the internal organs, followed by excessive intake of calcium into soft tissues. The main source of "pathological calcium" is the calcified kidney. In rare cases, the pathological process is primarily localized in the skin and with its further spread develop calcification of the tendon.
The development of calcification is facilitated by vascular disease and various collagenases, in which there is an overgrowth of the interstitial component. The initial manifestations of cutaneous calcification do not worsen the patient's condition and have only a cosmetic defect in the form of the appearance of many dense nodules that are painless on palpation and do not have inflammatory signs with predominant localization in the projection of the distal limbs.
The appearance of inflammatory changes in the calcitic region is accompanied by the formation of fistulas with purulent contents, as well as regional edema of soft tissues. Calcification of the skin can occur in both limited and widespread form, occupying most of the total surface of the skin. The most informative way to establish a reliable diagnosis is a histological study of a biomaterial containing a site of calcification.
The development of signs of excessive accumulation of calcium salts can be observed in any age period, both in the body of a healthy person, and in various pathologies. A separate form of this pathology that requires careful attention is calcification of the placenta, which in most cases accompanies the complicated course of pregnancy and belongs to one of the criteria for the development of fetoplacental insufficiency. The pathogenesis of the development of uteroplacental insufficiency is the violation of the supply of blood saturated with oxygen and nutrients due to the obstruction of the lumen of the placental vascular bundle by large calcification. However, in some cases, the presence of foci of calcification in the placenta does not have a significant effect on the process of normal fetal development, therefore this deviation does not need specific treatment and is subject to dynamic ultrasound observation only.
The development of calcification of the placenta is facilitated by a history of urogenital infection, an unbalanced dietary intake of a pregnant woman, and a pregnancy delay. Thus, the presence of signs of calcification of the placenta is not an unfavorable prognostic sign and is considered as a risk factor that provokes uteroplacental insufficiency in a combination of other predisposing factors.
When performing an ultrasound examination of a pregnant woman, the detection of even single calcifications should be reflected in the final examination protocol, since under conditions of other changes in thickness, size, and contours of the placenta, the presence of calcifications is considered as an indirect sign of "premature aging of the placenta".
It should be borne in mind that the appearance of calcification in the uterine cavity can be triggered not only by the aggravated pregnancy and the presence of calcifications of the placenta during pregnancy. Uterine calcification in most cases is a consequence or residual phenomenon of an inflammatory process, localized in endometrium or myometrium. No exception is the appearance of calcifications in the existing myomatous nodes, which is an unfavorable prognostic sign and is an indication for surgical treatment.
The influence of calcification on the health of the male sexual sphere is radically opposite, since the presence of calcinates in the prostate gland is considered an unfavorable sign of the development of possible complications in the form of various kinds of inflammatory diseases. The structure of the prostate gland is a favorable substrate for the accumulation of calcium salts, as it secrete a thick secret containing a mucus component. In addition, the presence of signs of uretero-prostatic reflux in 90% of cases provokes calcification of the prostate.
With widespread calcification with the defeat of most internal organs, spleen calcinosis can be observed, which is detected by screening ultrasound and does not have specific clinical manifestations.
Calcification of the aorta and aortic valve
According to most theories and scientific studies, calcification of the aorta in an isolated form is extremely rare, but if this occurs, the calcification of the valvular apparatus of the heart develops rapidly enough in the patient. The appearance of signs of calcification of aortic valve structures in the patient over time leads to severe hemodynamic disorders and diseases of an organic nature ( myocardial infarction , chronic heart failure ).
Most often calcification of the aortic valve flaps develops on the basis of the existing degenerative change in the rheumatic nature. Flabby, welded together valve flaps become a substrate for the formation of formless calcareous outgrowths overlapping the aortic lumen. With the long course of the disease, the pathological process of calcification extends to nearby structures and mitral calcification develops.
Diagnosis of calcification of the aortic valve in most situations is not difficult, provided the use of high-quality x-ray and ultrasound equipment. In this case, calcinosis foci are areas of increased density, with clear contours in the form of a solitary or multiple formation.
In a situation where the calcification process extends to the interventricular septum and reaches the valves of the mitral valve, calcification of the mitral valve develops. These pathological changes are not manifested by specific clinical and laboratory symptoms and are diagnosed only with the help of instrumental imaging techniques. Procrastination in terms of establishing the correct diagnosis inevitably leads to the development of gross cardiac malformations with severe hemodynamic disorders, which significantly worsens the patient's quality of life and shortens life expectancy. Provided early diagnosis and timely surgical correction of the defect, it comes the restoration of normal cardiac activity and a significant improvement in the patient's well-being.
When examining a patient by echocardioscopy, it should be borne in mind that the process of calcification can affect not only the valvular apparatus of the heart, but also spread on the myocardium in the field of physiological chords and be called "calcification of the heart." This localization of the pathological process of calcification is dangerous with complications consisting in sudden damage to the endothelium and concomitant valvular thrombosis . The danger of thrombosis is the rapid progression of thromboendocarditis and the development of signs of generalized sepsis.
According to the etiopathogenetic principle, atrial calcification is divided into the primary, which is a physiological manifestation of the aging of the organism, and secondary, which is provoked by any chronic pathological process in the body (heart diseases, metabolic disorders, endocrinopathies). Calcification of intracardiac localization is accompanied by clinical manifestations only in the late stage of the disease, when the processes of calcification have a negative effect on cardiohemodynamics. In this case, the patient may be disturbed by intermittent irregularities in the rhythm of cardiac activity, cardialgia and dizziness. The appearance of progressive dyspnoea indicates that the patient has an extreme degree of intracardiac calcification, in need of immediate surgical correction.
The widespread or localized parietal accumulation of calcium salts in vascular interstitia causes the disturbance of the normal blood flow and the occurrence of hemodynamic disorders in certain organs. Expressed changes in the human body provokes widespread calcification of large-sized arteries, which causes the development of ischemic damage to vital structures. The prevalence of a mechanism for the formation of calcification in the lumen of the vessels provokes the development of the calcification process in several ways (metastatic, interstitial and dystrophic). There is also a separate category of intravascular calcification, which debuts in the child's age period and causes congenital anomalies in the development of the vasculature.
The most severe and dangerous localization of intravascular calcification is the abdominal aorta, the calcification of which leads to the development of an aneurysm. The danger of this pathology lies in its latent clinical course and simultaneous threat of massive intra-abdominal bleeding when the integrity of the vascular wall is violated. In the case of timely diagnosis of calcification of the abdominal aorta, which is at the stage of aneurysm formation, the patient should undergo the resection of the altered aorta with subsequent defect plasty in the shortest possible time.
Calcification of kidneys (nephrocalcinosis)
With excess calcium content in the human body or a violation of its metabolic transformations, conditions are created for the excessive accumulation of its salts in the tissues of the parenchymal organs, and the kidneys in this situation are no exception. As a rule, nephrocalcinosis is a diffuse process of calcification combined with inflammatory changes in the renal parenchyma, which during a prolonged course inevitably provokes the development of all signs of renal insufficiency.
As with other forms of calcification, nephrocalcinosis can develop against a background of unchanged renal parenchyma or in absolutely unchanged kidneys. The primary form of nephrocalcinosis is not a separate nosological unit, and the mechanism of its development is based on the excessive intake of calcium in the body with food, medicines, and a violation of the total calcium metabolism in the endocrinopathy of the parathyroid glands. The substratum for the development of secondary nephrocalcinosis is necrotically altered renal parenchyma, ischemic damage to the kidneys and kidneys exposed to radiation exposure.
With the unchanged metabolism of calcium, the process of removing its residues from the body is placed on the organs of the urinary system, but with its excessive content, the kidneys are not able to release calcium in the urine in sufficient quantities, which results in the accumulation of calcium in the cells of the renal parenchyma. In the initial phase of the disease, excess calcium is deposited only on the epithelial cells of the tubules, and with prolonged flow, the calcification process is observed in the lumen of the renal tubules. In a situation where calcareous layers completely enclose the lumen of the tubules, the patient has signs of a violation of the urine-forming and urinary function of the kidneys. The final stage of calcification of the kidneys is the development of nephrosclerosis with concomitant renal failure.
Given the complete absence of timely diagnosis and treatment of calcification of the kidneys, the disease progresses and is accompanied by inflammatory changes and the development of urolithiasis. Unfortunately, specific manifestations of nephrocalcinosis are observed in the patient only in the terminal stage of the disease and more characterize the development of renal failure (pronounced edematous syndrome, malignant arterial hypertension , difficulty urinating).
The most informative diagnostic method for determining nephrocalcinosis in the initial phase of the pathological process is targeted puncture biopsy, the application of which does not apply to the screening algorithm of the patient. In the unfolded clinical-laboratory nephrocalcinosis stage, signs of calcification are well visualized when performing intravenous excretory urography, as well as ultrasonic scanning of the kidneys.
The detection of calcification in the lung tissue is a frequent finding of specialists in radiation imaging methods and in most clinical episodes patients do not even have an idea of their presence. This pattern takes place, since the appearance of calcareous changes in the pulmonary parenchyma can be provoked by a wide range of pathological conditions and, with limited localization, in no way affect lung function.
At risk for the development of signs of calcification of the lungs are people who have had at least one of the following pathologies in the history: tuberculosis lung infection, foreign body aspiration, pneumonic infiltration, parasitic lung infections, abscessed infiltrates and malignant neoplasms. Of course, in the predominant majority of cases, the process of calcification formation occurs in the altered pulmonary parenchyma, however, in pediatric practice, there are cases of the congenital nature of calcifications.
Experienced therapists and radiologists consider the process of formation of calcifications in the pulmonary parenchyma as a "key mechanism" that indicates the end of an acute period of a pulmonary disease and its transition to a subacute or latent stage, but it should be borne in mind that many pathogens of specific infections can be inactive for a long time state in the focus of calcification and show its activity at the slightest decrease in the immune natural protective properties of the organism.
Treatment of calcification
Due to the fact that calcification, as a systemic or limited pathological tissue change, is irreversible, the question of drug correction of this condition remains open and the only radical method for eliminating calcification sites is considered surgical. In any situation, therapeutic measures for calcification of one or another localization should be pathogenetically grounded and consistent in each individual situation.
Since calcification is prone to progressing and replacing the healthy tissue of any connective organ containing dense areas of calcification, with their multiple accumulation, the function of the organ can suffer significantly, which immediately reflects on the patient's state of health. In this regard, the primary therapeutic measure for calcification of any form, localization and intensity, is the correction of eating behavior, as well as the elimination of factors contributing to excessive intake of calcium in the body (taking medications, etc.).
In some situations, when the foci of pathological calcification are small and localized in a single order in the parenchyma of the organ, calcification does not pose a threat to the health of the patient and does not require the use of specific medications. However, there are a number of pathological forms of calcification accompanied by a pronounced impairment of the function of the organ, and therefore, the use of conservative or surgical measures in one or another volume is a prerequisite for maintaining the patient's normal quality of life.
Skin calcification usually has a widespread generalized character and provokes the development of a cosmetic defect, which is why, patients of this category need more than others the appointment of an adequate volume of therapeutic measures. In a situation where calcification is manifested by large subcutaneous nodes that are dense in structure and often accompanied by infection, the first and only effective method of treatment is surgery with electrocoagulation. This technique allows not only the most careful excision of calcinous foci, but also simultaneously disinfect the wound surface, thereby improving the healing process of the postoperative wound. If the calcification of the skin is localized in the area of large joints, the patient is recommended to use various methods of physiotherapeutic treatment to prevent the development of arthrosis-arthritis (galvanotherapy, application with ozocerite, ultraviolet irradiation).
Nephrocalcinosis also belongs to the category of rapidly progressing pathology, which, provided that there is no timely medication, provokes severe disorders of the urine-forming and urinary functions of the kidneys. In a situation where nephrocalcinosis is not accompanied by signs of renal failure, the patient should recommend compliance with the rules of dietary nutrition, as well as provide drug treatment for the underlying disease. With the existing signs of renal failure, the only effective method of treatment is hemodialysis followed by kidney transplantation.
Pregnant women who have foci of calcinosis in the placenta need dynamic ultrasound observation and when signs of fetoplacental insufficiency appear, it is recommended to prescribe drugs whose action is aimed at improving blood flow through the vascular network of the placenta and uterus (Trental 100 mg 2 times a day orally). In order to prevent premature detachment of the placenta in pregnant women suffering from calcification, it is advisable to prescribe drugs that reduce the uterine tone (Ginipral 5 μg intravenously). As a preventive treatment aimed at eliminating the progress of the calcification process, antiviral specific therapy is used.
The volume of therapy of calcification, localized in the projection of the valvular heart apparatus or large arterial vessels, is determined by its clinical form, as well as by the severity of hemodynamic disorders. So, single calcints in the projection of the subvalve department do not need specific treatment and it is enough to conduct dynamic echocardiographic observation. However, it should be borne in mind that intracardiac calcification is one of the pathologies of risk for the emergence of bacterial endocarditis , therefore, when signs of bacterial damage to the heart appear, an adequate antibiotic regimen should be immediately used.
Due to the fact that the centers of pathological calcification located in the vascular wall are a favorable substrate for thrombotic complications, all patients with signs of calcification of the heart and vessels are recommended lifelong administration of antiplatelet agents (Cardiomagnil 1 capsule once a day). Indication for the use of operative treatment of calcification is the development of signs of severe cardiohemodynamics.