What is Kidney Stone Disease?
Kidney stone disease is a common disease that tends to be endemic in nature. In the USSR, nephrolithiasis is often found in the Volga and Don basins, in the North Caucasus, and in Central Asia. Men get sick more often than women.
Causes of Kidney Stone Disease
The etiology of kidney stone disease is not well understood. The factors predisposing to the occurrence of stones include congenital and acquired changes in the urinary tract, creating impaired dynamics of urine and its stasis, various neurogenic dyskinesias and urinary tract infections (pyelonephritis, urethritis, etc.). A special role is played by metabolic disorders, uric acid and purine, oxalate and calcium phosphorus, sometimes called diathesis.
Dysfunction of the endocrine glands, primarily hyperfunction of the parathyroid glands, can cause the formation of stones in the urinary system. Hyperparathyroidism is characterized by hypercalcemia, hypercalciuria, hyperphosphaturia.
Hypervitaminosis D and hypovitaminosis A create the preconditions for the deposition of salts in the kidneys. Renal stone disease also contributes to liver, gastrointestinal tract dysfunction (hepatitis, gastritis, colitis). Diseases requiring prolonged rest of the body, in particular para- and hemiparesis, extensive bone fractures, diseases of the osteoarticular system are also often accompanied by stone formation in the urinary tract. The role of a hot and dry climate in the formation of stones is explained by a significant loss of fluid and an increase in urine concentration. Highly mineralized drinking water as a constant source of exogenous introduction of salts into the body is capable of causing renal lithiasis. The role of a hereditary predisposition in the origin of kidney stone disease cannot be completely ruled out.
Pathogenesis during Kidney Stone Disease
Stone formation is a complex physicochemical process, which is based on the violation of colloidal equilibrium in the tissues of the body, changes in the renal parenchyma.
With an insufficient concentration of protective colloids, a grouping of a number of molecules may form that form the so-called unit cell – the “micelle”, which is the nucleus of the future stone. The material for the formation of the nucleus can be an amorphous precipitate, fibrin, blood clot, cell detritus, bacteria, any foreign bodies in the urine. Further deposition of salts on the initial core will depend on the concentrations of the base salt and other salts contained in the urine, the concentration of hydrogen ions (pH) and, finally, the quantitative and qualitative composition of urinary colloids.
The location of the stones does not always coincide with the place of their formation. So, ureter stones are most often formed in the kidneys. Often, the process of stone formation begins in the papillae of the kidneys. Initially, the smallest primary micro calculi form in the lumen of the collecting tubules, most of which are freely excreted in the urine. In cases of a high concentration of urine, its supersaturation, and pH changes, crystallization occurs in the collecting tubules and the delay of microclumps at the mouth of the tubules with inlaid papillae. Subsequently, a small stone, first attached to the mouth of the papilla, disappears and becomes the secondary center of stone formation in the urinary tract.
According to the chemical composition of the stones can be homogeneous – oxalate, urate ,. phosphate, carbonate, cystine, xanthine, cholesterol and mixed. In acidic urine, stones from uric acid salts – urate, are found in alkaline urine – phosphates. Oxalates can be found in both acidic and alkaline urine. The sizes of stones vary from very small to the size of a large egg. Stones can be single and multiple. The presence of stones causes organic changes in the kidneys, depending on the duration of the stone in the kidney, its size, location, mobility, whether the stone is an obstacle to the passage of urine. With aseptic stones, pathological changes in the kidneys are characterized by a picture of calculous pyelonephritis, pyonephrosis, and sometimes perinephritis.
Symptoms of Kidney Stone Disease
Most often, kidney stone disease is observed at the age of 20-50 years.
The main symptoms of nephrolithiasis are: pain (renal colic), hematuria, pyuria, spontaneous discharge of stones with urine. Pain in the lumbar region is due to a violation of the normal passage of urine through the urinary tract, their intensity depends on the degree of violation of the outflow of urine. Large stones in the kidney (especially the so-called coral stones) cause mild, dull pains and, conversely, small, small stones in the upper urinary tract often cause sharp pain, the so-called renal colic.
Renal colic is accompanied by typical, sharp, sudden-onset pains in the lumbar region with irradiation along the ureter and into the genitals. Pain is accompanied by rapid and painful urination, vomiting, nausea, flatulence and other reflex phenomena. The patient behaves uneasily, rushing around. The pains are often so severe that they are second only to drug administration. The duration of the attack, as a rule, does not exceed a day. Most often, renal colic is caused by a pinched stone in the ureter, which leads to a delay in urine output, pyeloectasia, and an increase in intrarenal pressure. An attack of colic can be accompanied by a decrease in the amount of urine released, up to anuria of a reflex nature. Fever of the wrong type is observed.
An objective examination determines pain in the lumbar region, a positive symptom of Pasternatsky, sharp pain during palpation of the kidneys and along the ureter. In the urine after or less often during an attack, a small amount of protein, fresh red blood cells, white blood cells are found. In the peripheral blood during an attack, leukocytosis with a shift to the left, an increase in ESR, can be observed.
One of the signs of nephrolithiasis is the passage of stones with urine. Typically, the stones go away after an attack of renal colic.
Hematuria occurs due to damage to the mucous membrane of the urinary tract and small capillaries in the submucosal layer. Smooth stones (phosphates) less damage the urinary tract and less often cause hematuria. Stones with sharp edges (oxalates) often injure the mucous membrane and, therefore, often cause hematuria.
Hematuria as a symptom of kidney stone disease is common, and macrohematuria is less common than microhematuria. Macrohematuria is often observed at the end of an attack of renal colic or shortly after the end of it and is observed in 92% of patients with urolithiasis. The pyuria observed in some cases is due to the attachment of the inflammatory process in the urinary tract and in the kidneys.
The asymptomatic course of nephrolithiasis was observed in approximately 13% of patients. In this case, usually not finding significant morphological changes in the kidneys, as well as severe pyelonephritis.
The course of kidney stone disease
The course of kidney stone disease in most cases is favorable. Sometimes after the stone has passed away, the disease does not recur for a long time. A complication of nephrolithiasis infection significantly aggravates the course of the disease, leads to a chronic course of the process, to the development of calculous pyelonephritis with severe pyuria, symptomatic hypertension, chronic renal failure or hydropionephrosis. A particularly severe course with a tendency to massive bilateral stone formation with an outcome in renal failure is kidney stone disease caused by parathyroid adenoma with symptoms of hyper-parathyroidism. With bilateral nephrolithiasis and bilateral occlusion with stones of the ureters, excretory anuria often occurs.
The prognosis of most cases of kidney stone disease is favorable and becomes serious only with the addition of chronic pyelonephritis, or pyonephrosis, as well as with the development of persistent symptomatic hypertension or renal failure.
Diagnosis of Kidney Stone Disease
The diagnosis of kidney stone disease is based on anamnesis (colic), changes in urine (hematuria, pyuria), characteristic pains and their irradiation, urinary disorders, discharge of stones with urine, as well as data from x-ray and instrumental studies.
In typical cases, the diagnosis of renal colic is not difficult. However, with right-sided colic and atypical course, it is necessary to differentiate it with acute appendicitis or acute cholecystitis. In these cases, localization of pain, the absence of dysuric phenomena, changes in the urine, symptoms of peritoneal irritation, absent in renal colic, help.
Great difficulties arise when it is necessary to differentiate kidney stone disease with kidney infarction. It should be remembered that renal infarction occurs as a result of cardiovascular diseases, mainly atherosclerosis and rheumatic heart diseases, occurring with rhythm disturbances and heart failure. In these cases, despite back pain and hematuria, dysuric phenomena are usually not noted, pain rarely reaches extreme intensity, as is the case with kidney stones.
The main method for recognizing urinary tract stones is an X-ray. With the help of overview pictures, it is possible to identify most of the stones. However, soft uric acid or protein stones that do not delay x-rays do not give a shadow in the survey picture. To identify them, tomography, pneumo-pyelography, excretory urography are used.
Following a panoramic image (regardless of the presence or absence of a calculus shadow on the radiograph), excretory urography is necessary to determine the functional ability of the kidneys and urinary tract.
In cases where excretory urography does not give an idea of functional and anatomical changes in the kidney (calculous hydronephrosis, pyonephrosis), retrograde pyelography and isotopic renography are used. With the help of urography, it is possible to clarify the localization of the calculus (calyx, pelvis, ureter), to reveal the degree of functional disorders in the kidney and upper urinary tract, which is necessary for the correct choice of treatment.
Treatment of Kidney Stone Disease
To combat urinary infection Prescribe antibiotics, sulfa drugs, nitrofurans.
In some patients, stone formation in the kidneys is caused by abnormalities of calcium metabolism and is observed with hyperfunction of the parathyroid glands, hypervitaminosis D, and prolonged immobility of the body. Under these conditions, various disorders of calcium metabolism occur. With parathyroid adenoma, its removal is necessary.
With uric acid diathesis in the diet, the amount of purine bases should be reduced. Fried meat, brains, liver, meat broth are excluded from food. A patient with urate stones is prescribed a milk-vegetable diet, since it, alkalizing urine, lowers acidosis. With oxaluria, foods that promote the excretion of oxalate salts and alkalize urine are recommended. With phosphate stones, acidic mineral waters of Kislovodsk, Truskavets, Zhelezno-Vodsk are recommended (all year round), with uraturia – alkaline waters of Borjomi, Zheleznovodsk, Essentuki, Truskavets, with oxaluria – Essentuki, Zheleznovodsk, Pyatigorsk (all year round); patients with kidney and ureter stones with an acid reaction of urine – water of Zheleznovodsk, Borjomi,
Truskavets, Essentukov, with an alkaline reaction – Truskavets, Zheleznovodsk (all year round).
Spa treatment is indicated after removal of kidney stones, as well as for patients who have anatomical and physiological conditions of the urinary tract, which allows us to hope for an independent passage of stones.
With renal colic in the case of mild pain, you can limit yourself to injecting 1 ml of 2 ° 7 ° pantopone or morphine in combination with 1 ml of a 0.1% atropine solution, at the same time with a warm bath or a heating pad on the belt ~ the area. With pronounced renal colic, as well as in cases where the pain does not quickly disappear after injection of opiates, it is necessary to apply novocaine anesthesia of the spermatic cord or uterine round ligament. In cases where there is no effect from the above measures, endovascular manipulations are necessary – catheterization of the ureter or dissection of the ureteral orifice, if the stone is infringed in the intramural part of the ureter.
Indications for the operation are: strong, often recurring attacks of renal colic, acute and chronic pyelonephritis, complicating kidney stone disease, when it is difficult to count on stone discharge, large ureter stones and stones complicated by stricture; kidney blockage caused by a stone, if after a week the kidney function is not restored; ureteral stones that do not migrate for 3 months; single kidney stones; hematuria, life-threatening patient.
Prevention of Kidney Stone Disease
In the prevention of urolithiasis, attention should be paid to concomitant infectious and inflammatory processes in the urinary tract, bearing in mind that they are most often caused by pyelonephritis, which tends to occur latently for a long time.
For the prevention of calculous pyelonephritis, it is necessary to carry out early surgical intervention on the urinary tract in order to extract calculus, and in the presence of a virulent infection – drainage of the pelvis, chemotherapy.