Blood supply to the kidneys and its disorders. What diseases affect the renal artery Renal arteries and veins

Antipyretics for children are prescribed by a pediatrician. But there are emergency situations with fever when the child needs to be given medicine immediately. Then the parents take responsibility and use antipyretic drugs. What is allowed to be given to infants? How can you lower the temperature in older children? What medications are the safest?

Renal artery stenosis (RAS) is a serious disease accompanied by narrowing of the lumen of the vessel supplying the kidney. The pathology is the responsibility of not only nephrologists, but also cardiologists, since the main manifestation is usually strong and difficult to correct.

Patients with renal artery stenosis are predominantly older people (after 50 years), but stenosis can also be diagnosed in young people. Among older people with vascular atherosclerosis, there are twice as many men as women, and with congenital vascular pathology, females predominate, in whom the disease manifests itself after 30-40 years.

Every tenth person suffering from high blood pressure has stenosis of the main renal vessels as the main cause of this condition. Today, more than 20 different changes are already known and described, leading to narrowing of the renal arteries (RA), an increase in pressure and secondary sclerotic processes in the parenchyma of the organ.

The prevalence of pathology requires the use of not only modern and accurate diagnostic methods, but also timely and effective treatment. It is recognized that the best results can be achieved when carrying out surgical treatment stenosis, while conservative therapy plays a supporting role.

Causes of VA stenosis

Most common reasons narrowing of the renal artery - atherosclerosis and fibromuscular dysplasia of the artery wall. Accounting for up to 70% of cases, fibromuscular dysplasia accounts for approximately a third of cases.

Atherosclerosis renal arteries with narrowing of their lumen is usually found in elderly men, often with existing coronary disease heart, diabetes, obesity. Lipid plaques are more often located in the initial segments of the renal vessels, near the aorta, which can also be affected by atherosclerosis; the middle section of the vessels and the branching zone in the organ parenchyma are much less often affected.

Fibromuscular dysplasia is a congenital pathology in which the wall of the artery thickens, which leads to a decrease in its lumen. This lesion is usually localized in the middle part of the VA, is diagnosed 5 times more often in women and can be bilateral.

atherosclerosis (right) and fibromuscular dysplasia (left) are the main causes of VA stenosis

About 5% of RAS is caused by other reasons, including inflammatory processes of the vascular walls, aneurysmal dilation of the renal arteries, compression by a tumor located externally, and prolapse of the kidney. Intrauterine developmental disorders occur in children vascular system with VA stenosis, which will manifest itself as hypertension in childhood.

Both unilateral and bilateral stenosis of the renal arteries is possible. Damage to both vessels is observed in congenital dysplasia, atherosclerosis, and is more malignant, because two kidneys are in a state of ischemia at once.

When blood flow through the renal vessels is disrupted, the system that regulates the level of blood pressure. The hormone renin and angiotensin-converting enzyme contribute to the formation of a substance that causes spasm of small arterioles and an increase in peripheral vascular resistance. The result is hypertension. At the same time, the adrenal glands produce excess aldosterone, under the influence of which fluid and sodium are retained, which also increases blood pressure.

If even one of the arteries is damaged, right or left, the mechanisms of hypertension described above are triggered. Over time, the healthy kidney “rebuilds” to a new level of pressure, which continues to be maintained even if the diseased kidney is removed completely or blood flow in it is restored by angioplasty.

In addition to activation of the pressure maintenance system, the disease is accompanied by ischemic changes in the kidney itself. Against the backdrop of a lack of arterial blood, tubular degeneration occurs and the connective tissue in the stroma and glomeruli of the organ, which over time inevitably leads to atrophy and nephrosclerosis. The kidney becomes denser, shrinks and is unable to perform its assigned functions.

Manifestations of SPA

For a long time, SPA can exist asymptomatically or in the form of benign hypertension. Bright Clinical signs diseases appear when the narrowing of the vessel reaches 70% . Among the symptoms, the most typical are renal arterial hypertension and signs of parenchymal dysfunction (decreased urine filtration, intoxication with metabolic products).

Persistent increase in pressure, usually without hypertensive crises, in young patients, leads the doctor to think about possible fibromuscular dysplasia, and if the patient has crossed the 50-year mark, atherosclerotic damage to the renal vessels is most likely.

Among the complaints of patients with renal hypertension are:

Severe headaches, tinnitus, flashing “spots” before the eyes;
Decreased memory and mental performance;
Weakness;
Dizziness;
Insomnia or daytime sleepiness;
Irritability, emotional instability.

A constant high load on the heart creates conditions for it; patients complain of chest pain, palpitations, a feeling of interruptions in the functioning of the organ, shortness of breath appears, and in severe cases, pulmonary edema develops, requiring emergency care.

In addition to hypertension, heaviness and pain in the lumbar region, blood in the urine, and weakness are possible. In case of excess secretion of aldosterone by the adrenal glands, the patient drinks a lot, excretes a large amount of unconcentrated urine not only during the day, but also at night, and convulsions are possible.

At the initial stage of the disease, kidney function is preserved, but hypertension already appears, which, however, can be treated with medication. Subcompensation is characterized by a gradual decrease in kidney function, and in the stage of decompensation, signs of renal failure are clearly visible. Hypertension in the terminal stage becomes malignant, the pressure reaches its maximum levels and is not “knocked down” by medications.

SPA is dangerous not only for its manifestations, but also for complications in the form of cerebral hemorrhages, myocardial infarction, pulmonary edema due to hypertension. In most patients, the retina of the eyes is affected, and its detachment and blindness are possible.

Chronic renal failure, as the final stage of pathology, is accompanied by intoxication with metabolic products, weakness, nausea, headache, a small amount of urine that the kidneys can filter on their own, and an increase in edema. Patients are susceptible to pneumonia, pericarditis, inflammation of the peritoneum, damage to the mucous membranes of the upper respiratory tract and digestive tract.

How to detect renal artery stenosis?

Examination of a patient with suspected stenosis of the left or right renal artery begins with a detailed clarification of complaints, the time of their onset, and the response to conservative treatment of hypertension, if it has already been prescribed. Next, the doctor will listen to the heart and large vessels, prescribe blood and urine tests and additional instrumental examinations.

stenosis of both renal arteries on angiography

During the initial examination, it is already possible to detect an enlargement of the heart due to hypertrophy of the left parts, and an increase in the second sound above the aorta. A murmur is heard in the upper abdomen, indicating narrowing of the renal arteries.

Main biochemical indicators with SPA there will be levels and , which increase due to insufficient filtration capacity of the kidneys. Red blood cells, white blood cells, and protein casts can be found in the urine.

From additional methods diagnostics are used Ultrasound(kidneys are reduced in size), and dopplerometry allows you to record the narrowing of the artery and the change in the speed of blood movement through it. Information about the size, location, and functionality can be obtained through radioisotope research.

The most informative diagnostic method is recognized when the localization, degree of stenosis of the VA and hemodynamic disturbances are determined using contrast radiography. It is also possible to carry out CT And MRI.

Treatment of renal artery stenosis

Before starting treatment, the doctor will recommend that the patient give up bad habits, start following a diet with reduced salt intake, limit fluids, fats and easily accessible carbohydrates. In atherosclerosis with obesity, weight loss is necessary, since obesity can create additional difficulties when planning surgical intervention.

Conservative therapy for renal artery stenosis is auxiliary, it does not eliminate the underlying cause of the disease. At the same time, patients need correction of blood pressure and urination. Long-term therapy is indicated for elderly people and persons with widespread atherosclerotic vascular disease, including coronary arteries.

Since the main manifestation of renal artery stenosis is symptomatic hypertension, treatment is aimed primarily at reducing blood pressure. For this purpose, diuretics are prescribed. It is worth considering that with a strong narrowing of the lumen of the renal artery, a decrease in pressure to normal levels contributes to the worsening of ischemia, because in this case even less blood will flow to the parenchyma of the organ. Ischemia will cause the progression of sclerotic and dystrophic processes in the tubules and glomeruli.

The drugs of choice for hypertension against the background of VA stenosis are (capropril), but for atherosclerotic vasoconstriction they contraindicated including persons with congestive heart failure and diabetes mellitus, therefore the following are replaced:

Cardioselective (atenolol, egilok, bisoprolol);
(verapamil, nifedipine, diltiazem);
Alpha adrenergic blockers (prazosin);
Loops (furosemide);
Imidazoline receptor agonists (moxonidine).

Doses medicines are selected individually, while it is advisable to avoid a sharp decrease in pressure, and when selecting correct dosage The drug controls the level of creatinine and potassium in the blood.

Patients with atherosclerotic stenosis need to be prescribed to correct lipid metabolism disorders; for diabetes, lipid-lowering drugs or insulin are indicated. To prevent thrombotic complications, aspirin and clopidogrel are used. In all cases, the dosage of drugs is selected taking into account the filtration capacity of the kidneys.

In case of severe renal failure due to atherosclerotic nephrosclerosis, patients are prescribed hemodialysis or peritoneal dialysis on an outpatient basis.

Conservative treatment often does not give the desired effect, because stenosis cannot be eliminated with drugs, so the main and most effective measure can only be surgery, the indications for which are:

Severe stenosis, causing hemodynamic disturbances in the kidney;
Narrowing of the artery in the presence of a single kidney;
Malignant hypertension;
Chronic failure organ when one of the arteries is damaged;
Complications (pulmonary edema, unstable angina).

Types of interventions used in SPA:

Stenting involves installing a special tube made of synthetic materials into the lumen of the renal artery, which is strengthened at the site of stenosis and allows blood flow to improve. With balloon angioplasty, a special balloon is inserted through a catheter through the femoral artery, which is inflated in the area of stenosis and thereby expands it.

Video: angioplasty and stenting - a minimally invasive method of treating SPA

For atherosclerosis of the renal vessels best effect will give bypass surgery, when the renal artery is sutured to the aorta, excluding the site of stenosis from the bloodstream. It is possible to remove a section of the vessel and subsequent prosthetics using the patient’s own vessels or synthetic materials.

A) Renal artery replacement and B) Bilateral RA bypass with a synthetic prosthesis

If it is impossible to perform reconstructive interventions and the development of atrophy and sclerosis of the kidney, removal of the organ (nephrectomy) is indicated, which is performed in 15-20% of cases of pathology. If stenosis is caused congenital causes, then the need for a kidney transplant is considered, while for vascular atherosclerosis such treatment is not carried out.

IN postoperative period Complications in the form of bleeding and thrombosis in the area of anastomoses or stents are possible. Restoring an acceptable level of blood pressure may require up to six months, during which conservative antihypertensive therapy continues.

The prognosis of the disease is determined by the degree of stenosis, the nature of secondary changes in the kidneys, the effectiveness and possibility of surgical correction of the pathology. With atherosclerosis, slightly more than half of patients return to normal indicators pressure, and in the case of vascular dysplasia, surgical treatment allows it to be restored in 80% of patients.

The blood supply to the kidney is significantly different from the blood supply to other parts of the body. This is primarily due to the fact that the blood must not only support the functioning of the organ, but also contribute to the accumulation and removal of urine, as well as the harmful substances it contains.

Although the total kidney mass is only 0.004% of the total body mass, it interacts with 1/5 of the body's total blood, in addition, it has its own system for maintaining a stable pressure that does not fluctuate with changes in blood pressure in the body .

Features of the renal blood supply

The main renal blood flow is provided by arteries connected to the abdominal aorta. There is only one main artery leaving the aorta, but when it enters the portal of the organ, it is divided into three parts:

This becomes possible, not least due to its extreme thickness, which allows the kidney to be fully saturated with blood. The secondary arteries are extremely short, and inside the organ they almost immediately divide into renal vessels, the so-called arterioles. The cortex and medulla are united by the arcuate artery, which is divided into several smaller ones, thus the blood supply to the kidney in part of the glomeruli is provided by arterioles.

Getting directly into the capsule that forms the base of the glomerulus, the kidney vessels are divided into a large number of capillary branches, which intertwine into the glomerulus itself, and then unite into the efferent artery. They also contribute to the nutrition of the cortex, gradually passing into the capillaries of the veins.

The renal vein removes blood from the kidneys, collecting it from several other veins that penetrate the entire renal parenchyma (i.e., the main functional tissue of the organ). Among these veins are the following:

star-shaped;
interlobular;
arc;
interlobar.

It is the fusion of the interlobar veins that forms the renal vein. Moreover, throughout the entire course of venous blood flowing from the kidneys, it is paralleled by arteries of the same name, which in turn carry blood to the kidneys.

A key feature of the blood supply to this organ is also the presence of two capillary systems at once:

System of communicating vascular glomeruli.
A system that connects the renal arteries and veins.

Thanks to this, the kidneys are able to perform their main functions of removing excess water and toxins from the body.

Kidney diseases related to the blood supply

Among the key diseases that impair the blood circulation of the kidney are the following:

Many of these abnormalities are quite common and treatable.

Kidney failure

This disease, characterized by the rapid destruction of kidney tissue, is usually caused by intoxication. It develops quite quickly and goes through 4 stages:

Stage	Externally noticeable symptoms	Internal changes
1. Shock	A sharp decrease in the amount of urine	Drop in blood pressure
2. Oligoanuric. At this stage, death due to poisoning is possible harmful substances which are no longer excreted from the body.	headaches and dizziness; urge to vomit; coating on the tongue; increased and weakened pulse; development of shortness of breath; decreased amount of urine; increasing lower back pain.	decrease in hemoglobin level (development of anemia); increase in residual ozone.
3. Diuretic-restorative. During this stage, you must carefully avoid all infectious diseases, they can cause severe complications.	Urine appears again, sometimes even in excessive quantities	Residual nitrogen exceeds the norm, but its level gradually decreases
4. Recovery. This stage is characterized by complete restoration of normal renal functions.	The amount of urine returns to normal	Nitrogen levels drop to normal

Accessory artery

The blood supply to the kidney is often associated with an anomaly such as an accessory artery. It is smaller in size than the main artery and, as a rule, is inferior or superior pole. Their number can reach three or more:

As a rule, the right renal artery, which is accompanied by an additional arterial canal, is mainly affected by this anomaly. Women experience this feature more often than men.

Accessory arteries do not cause any harm except in rare cases when they put pressure on the ureter. The concepts of “accessory artery” and “accessory vessel” should not be confused. The development of an accessory vessel can put severe pressure on the ureters, interfere with blood supply and require surgical intervention.

Thrombosis and aberrant arteries

Renal thrombosis is associated with a blockage of the veins or arteries that supply the organ. By itself, it almost never develops, and the treatment of thrombosis is closely related to the treatment of the underlying disease. There are several reasons for its appearance:

development of atherosclerosis;
formation of a malignant tumor;
nephrotic syndrome.

The appearance of arteries, the size and shape of which deviate from the usual, is usually associated with changes in the structure of the muscular walls of the vessels. There are two types of deviations:

Aneurysm (expansion).
Stenosis (narrowing).

Blood supply to the kidney

Such anomalies can be extremely dangerous. They call:

ruptures of blood vessels, accompanied by heavy bleeding;
decreased blood circulation to the kidney;
increase in blood pressure;
accumulation of toxic substances.

In the case of aneurysms and stenoses, surgical intervention is often required.

Venous anomalies

Venous anomalies are much more common than arterial ones, but surgical intervention, in this case is not required. As a rule, they have virtually no effect on the circulatory system in the kidneys.

Among them:

In addition to the listed diseases, problems with blood circulation in the kidneys can also be caused by general problems of the body and its cardiovascular system. Often the kidneys are affected by coronary heart disease. The vessels of the kidneys also suffer from the development of purulent inflammation associated with disturbances in the movement of urine.

Since it is almost impossible to accurately determine the cause of the disease on your own, and kidney problems develop extremely quickly, it is necessary to consult a doctor at the first signs of disturbances and undergo the appropriate examinations and the necessary course of treatment.

The prevalence of pathology requires the use of not only modern and accurate diagnostic methods, but also timely and effective treatment. It is recognized that the best results can be achieved with surgical treatment of stenosis, while conservative therapy plays a supporting role.

Causes of VA stenosis

The most common causes of narrowing of the renal artery are atherosclerosis and fibromuscular dysplasia of the artery wall. Atherosclerosis accounts for up to 70% of cases of the disease, fibromuscular dysplasia accounts for approximately a third of cases.

Atherosclerosis renal arteries with narrowing of their lumen is usually found in elderly men, often with existing coronary heart disease, diabetes, and obesity. Lipid plaques are more often located in the initial segments of the renal vessels, near the aorta, which can also be affected by atherosclerosis; the middle section of the vessels and the branching zone in the parenchyma of the organ are much less often affected.

atherosclerosis (right) and fibromuscular dysplasia (left) are the main causes of VA stenosis

About 5% of RAS is caused by other reasons, including inflammatory processes of the vascular walls, aneurysmal dilatations, thrombosis and embolism of the renal arteries, compression by a tumor located externally, Takayasu's disease, and kidney prolapse. In children, there is an intrauterine developmental disorder of the vascular system with VA stenosis, which manifests itself as hypertension in childhood.

Both unilateral and bilateral stenosis of the renal arteries is possible. Damage to both vessels is observed in congenital dysplasia, atherosclerosis, diabetes and is more malignant, because two kidneys are in a state of ischemia at once.

When blood flow through the renal vessels is disrupted, the system that regulates blood pressure levels is activated. The hormone renin and angiotensin-converting enzyme contribute to the formation of a substance that causes spasm of small arterioles and an increase in peripheral vascular resistance. The result is hypertension. At the same time, the adrenal glands produce excess aldosterone, under the influence of which fluid and sodium are retained, which also increases blood pressure.

If even one of the arteries, right or left, is damaged, the mechanisms of hypertension described above are triggered. Over time, the healthy kidney “rebuilds” to a new level of pressure, which continues to be maintained even if the diseased kidney is removed completely or blood flow in it is restored by angioplasty.

In addition to activation of the pressure maintenance system, the disease is accompanied by ischemic changes in the kidney itself. Against the background of a lack of arterial blood, tubular degeneration occurs, connective tissue grows in the stroma and glomeruli of the organ, which over time inevitably leads to atrophy and nephrosclerosis. The kidney becomes denser, shrinks and is unable to perform its assigned functions.

Manifestations of SPA

For a long time, SPA can exist asymptomatically or in the form of benign hypertension. Vivid clinical signs of the disease appear when the narrowing of the vessel reaches 70%. Among the symptoms, the most typical are secondary renal arterial hypertension and signs of parenchymal dysfunction (decreased urine filtration, intoxication with metabolic products).

A persistent increase in pressure, usually without hypertensive crises, in young patients prompts the doctor to think about possible fibromuscular dysplasia, and if the patient has crossed the 50-year mark, most likely atherosclerotic damage to the renal vessels.

Renal hypertension is characterized by an increase in not only systolic but also diastolic pressure, which can reach 140 mmHg. Art. and more. This condition is extremely difficult to treat with standard antihypertensive drugs and creates a high risk of cardiovascular disasters, including stroke and myocardial infarction.

Among the complaints of patients with renal hypertension are:

Severe headaches, tinnitus, flashing “spots” before the eyes; Decreased memory and mental performance; Weakness; Dizziness; Insomnia or daytime sleepiness; Irritability, emotional instability.

A constant high load on the heart creates conditions for its hypertrophy; patients complain of chest pain, palpitations, a feeling of interruptions in the functioning of the organ, shortness of breath appears, and in severe cases, pulmonary edema develops, requiring emergency care.

At the initial stage of the disease, kidney function is preserved, but hypertension already appears, which, however, can be treated with medication. Subcompensation is characterized by a gradual decrease in kidney function, and in the stage of decompensation, signs of renal failure are clearly visible. Hypertension in the terminal stage becomes malignant, the pressure reaches maximum values and is not “knocked down” by medications.

SPA is dangerous not only for its manifestations, but also for complications in the form of cerebral hemorrhages, myocardial infarction, pulmonary edema due to hypertension. In most patients, the retina of the eyes is affected, and its detachment and blindness are possible.

How to detect renal artery stenosis?

stenosis of both renal arteries on angiography

The main biochemical indicators in SPA will be the level of creatinine and urea, which increase due to insufficient filtration capacity of the kidneys. Red blood cells, white blood cells, and protein casts can be found in the urine.

Of the additional diagnostic methods, ultrasound is used (the kidneys are reduced in size), and Doppler measurements make it possible to record the narrowing of the artery and changes in the speed of blood movement through it. Information about the size, location, and functionality can be obtained through radioisotope research.

Arteriography is recognized as the most informative diagnostic method, when the location, degree of VA stenosis and hemodynamic impairment are determined using contrast radiography. CT and MRI may also be performed.

Treatment of renal artery stenosis

Before starting treatment, the doctor will recommend that the patient give up bad habits, start following a diet with reduced salt intake, limit fluids, fats and easily accessible carbohydrates. In atherosclerosis with obesity, weight loss is necessary, since obesity can create additional difficulties when planning surgical intervention.

Since the main manifestation of renal artery stenosis is symptomatic hypertension, treatment is aimed primarily at reducing blood pressure. For this purpose, diuretics and antihypertensive drugs are prescribed. It is worth considering that with a strong narrowing of the lumen of the renal artery, a decrease in pressure to normal levels contributes to the worsening of ischemia, because in this case even less blood will flow to the parenchyma of the organ. Ischemia will cause the progression of sclerotic and dystrophic processes in the tubules and glomeruli.

The drugs of choice for hypertension against the background of VA stenosis are ACE inhibitors (capropril), however, in case of atherosclerotic vasoconstriction, they are contraindicated, including for persons with congestive heart failure and diabetes mellitus, therefore they are replaced by:

Cardioselective beta blockers (atenolol, egilok, bisoprolol); Blockers of slow calcium channels (verapamil, nifedipine, diltiazem); Alpha adrenergic blockers (prazosin); Loop diuretics (furosemide); Imidazoline receptor agonists (moxonidine).

Doses of medications are selected individually, and it is advisable to avoid a sharp decrease in blood pressure, and when selecting the correct dosage of the drug, the level of creatinine and potassium in the blood is monitored.

Patients with atherosclerotic stenosis need statins to correct lipid metabolism disorders; for diabetes, lipid-lowering drugs or insulin are indicated. To prevent thrombotic complications, aspirin and clopidogrel are used. In all cases, the dosage of drugs is selected taking into account the filtration capacity of the kidneys.

In case of severe renal failure due to atherosclerotic nephrosclerosis, patients are prescribed hemodialysis or peritoneal dialysis on an outpatient basis.

Severe stenosis, causing hemodynamic disturbances in the kidney; Narrowing of the artery in the presence of a single kidney; Malignant hypertension; Chronic organ failure due to damage to one of the arteries; Complications (pulmonary edema, unstable angina).

Types of interventions used in SPA:

Stenting and balloon angioplasty; Bypass; Resection and prosthetics of a section of the renal artery; Kidney removal;

angioplasty and stenting of VA

Transplantation.

Video: angioplasty and stenting - a minimally invasive method of treating SPA

For atherosclerosis of the renal vessels, shunting will give the best effect, when the renal artery is sutured to the aorta, excluding the site of stenosis from the bloodstream. It is possible to remove a section of the vessel and subsequent prosthetics using the patient’s own vessels or synthetic materials.

A) Renal artery replacement and B) Bilateral RA bypass with a synthetic prosthesis

If it is impossible to perform reconstructive interventions and the development of atrophy and sclerosis of the kidney, removal of the organ (nephrectomy) is indicated, which is performed in 15-20% of cases of pathology. If the stenosis is caused by congenital causes, then the need for a kidney transplant is considered, while in case of vascular atherosclerosis such treatment is not carried out.

In the postoperative period, complications are possible in the form of bleeding and thrombosis in the area of anastomoses or stents. Restoring an acceptable level of blood pressure may require up to six months, during which conservative antihypertensive therapy continues.

The prognosis of the disease is determined by the degree of stenosis, the nature of secondary changes in the kidneys, the effectiveness and possibility of surgical correction of the pathology. With atherosclerosis, slightly more than half of patients return to normal blood pressure after surgery, and in the case of vascular dysplasia, surgical treatment allows it to be restored in 80% of patients.

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Renal artery stenosis (RAS) is a fairly common disease that affects older men and women over 30 years of age. Why is that? The answer is ambiguous, but assumptions about such a development of events modern medicine provides.

Let us consider in detail what renal artery stenosis is and what types of this pathology are known. Causes of the disease and the most common symptoms. Modern methods treatment of pathology, including traditional methods.

What is a SPA and what is it like?

Renal artery stenosis is a nephropathic disease. It is caused by stenosis (narrowing) or permanent blockage (occlusion) of the arteries leading to the kidneys.

This disease can affect one or both kidneys. Unilateral pathology causes circulatory problems in one organ, but both suffer, since the second (healthy) kidney is subjected to increased stress.

Bilateral, or bilateral, stenosis is a very serious disease, since the functions of the paired organ are impaired and it is almost impossible to compensate for them. Patients with this pathology are often forced to regularly undergo a procedure such as hemodialysis - blood purification through an “artificial kidney” device.

There are two types of stenosis, which differ in the localization of arterial damage:

Atherosclerotic – accounts for up to 90% of cases of this disease and is typical for the older age group, mainly in the male population. General vascular atherosclerosis, caused by various factors, affects arteries throughout the body, including the kidneys. The highest risk group includes patients with diabetes mellitus and damage to the iliac arteries, aortic dysfunction and hypertension. It is this type of stenosis that is predicted to be the most unfavorable and requires hemodialysis in especially severe cases. Pathological narrowing is observed at the mouth of the arteries leading to the kidneys. Fibromuscular dysplasia - the lesion is localized in the middle and distal part of the arteries. This is quite a rare species pathological process, which is typical for the fair sex between the ages of 15 and 50 years. The exact causes of this pathology have not yet been established.

Renal vascular stenosis can be congenital. This is a consequence of intrauterine infections, pathological pregnancy or genetic predisposition. In this case, treatment begins immediately. In especially severe cases, a kidney transplant is required.

Causes and symptoms

Renal vascular stenosis is a vascular disease. His treatment is carried out not only by a nephrologist, but also by a cardiologist and a vascular surgeon.

Often, determining the causes of this pathology can help prescribe the correct therapy or surgical treatment:

Atherosclerosis is the most common and likely cause of stenosis, which is typical for older patients. Moreover, men over the age of 50 suffer from this disease 2 times more often than women. Fibromuscular dysplasias are mainly congenital defects in the vascular walls, leading over time to their spasm and the development of renal stenosis.

Heredity - as one of the possible development factors vascular pathologies, including kidney ones. Acute diseases kidneys or frequently recurrent chronic pathologies. Obesity or increased body mass index, which are characteristic of some endocrine pathologies - in particular, diabetes mellitus. Increased concentration of cholesterol in the blood, which provokes the risk of developing atherosclerosis and the formation of cholesterol plaques on the walls of blood vessels. Bad habits - smoking, drinking alcohol, even weak (but regularly and often). Hypertension. This disease is generally very “interesting” in connection with renal artery stenosis. In itself, it is the cause of the development of pathology of the renal vessels, but it is also a consequence of stenosis. The so-called “renal pressure” is one of the most uncontrollable and difficult to correct types of increased blood pressure.

Renal artery stenosis is not a specific disease in terms of symptoms. Each patient, depending on the cause of this pathology, may develop “its own” symptoms.

But the general clinical picture something like this:

blood pressure surges. Its indicators can reach 220-250/140-170 mm Hg. Art. Moreover, antihypertensive drugs provide a short-term effect; frequent headaches with dizziness, accompanied by “spots” before the eyes, as well as tinnitus; blurred vision, especially with high blood pressure. There is a painful feeling in eyeballs; general weakness, sudden mood swings, deterioration of concentration and memory, insomnia at night and drowsiness during the day; chest pain radiating to the heart and left arm. This symptom is especially characteristic if there is stenosis of the left renal artery; tachycardia, accompanied by shortness of breath even at rest; pain in the lower back in the projection of the kidneys, which is aching and pulling; A urine test reveals a small amount of protein.

One of characteristic features Renal artery stenosis can be called a significant discrepancy in blood pressure readings in the right and left arms.

Treatment

The main and most dangerous symptom of renal artery stenosis is considered to be increased blood pressure. All therapeutic measures will be aimed mainly at resolving this particular problem. However, renal artery stenosis, in the treatment of which only conservative therapy is used, remains a pathology. After all, the cause itself has not been eliminated - the narrowing of a vessel that feeds an important organ of the human body.

For this pathology, treat high blood pressure The following drugs are recommended:

cardioselective beta blockers - Atenolol, Bisoprolol and others; calcium channel blockers - Verapamil, Nifedipine and others; adrenergic blockers; diuretics.

What kind of drug will be prescribed, its dosage and frequency of administration will be determined by a specialist after a number of studies. However, surgical intervention will get rid of the problem itself, and there will be no need to carry out symptomatic treatment, at least in such doses of drugs and with such intensity.

Determination of surgical treatment tactics is carried out in each specific case after determining the stage of stenosis, general condition the patient, his age and the presence of contraindications.

Bilateral renal artery stenosis requires mandatory surgery to restore the function of at least one organ. Otherwise, the patient will be doomed to undergo hemodialysis throughout his life. After all, the kidneys filter the blood and remove toxins formed during life. If filtration is not forced during stenosis, then poisoning of the body will inevitably occur, which will lead to death.

Surgery is performed using several methods:

Shunting is the creation of “bypass” pathways for blood flow in the kidney. Angioplasty - the introduction of a special balloon, which is inflated inside the affected vessel and restores the lumen. Stenting – insertion of a spring stent to maintain the vessel in an “opened” state for the unimpeded passage of blood. Resection followed by prosthetics. The damaged section of the artery is removed and reconstruction is performed using an implant. Nephrectomy – removal of a damaged organ. This operation is performed only in extreme cases when there is significant damage to the organ and other types of intervention are ineffective.

Traditional medicine can offer its own treatment recipes, but rather for pressure rather than stenosis as such. These methods will be effective in case of a slightly pronounced process of damage to the renal arteries, when the functions of the kidneys have not been affected and their sizes have not changed - that is, at the most initial stages diseases.

An infusion of rosehip and hawthorn will have a mild diuretic effect, cleanse blood vessels, strengthen their walls and increase immunity.

To prepare you will need:

4 tbsp. l. rose hips, 8 tbsp. l. hawthorn; 2 liters of boiling water.

Pour boiling water over the plant material in a thermos and leave for 6 hours. Take a glass three times a day, preferably before meals.

A decoction of rowan bark has a similar effect.

To prepare you need:

100 g rowan bark; one and a half glasses of water.

In an enamel saucepan, bring water to a boil, add the bark and simmer over very low heat for about 2 hours. Then cool the broth, strain and squeeze. You need to store the liquid in the refrigerator, take 3 tbsp. l. before meals two to three times a day - depending on blood pressure readings.

Renal vascular pathologies are a serious disease. There is no need to ignore even the slightest symptoms in order to start treatment on time.

Renal artery – paired terminal blood vessel, extending from the lateral surfaces of the abdominal aorta and supplying blood to the kidney. The renal arteries bring blood to the apical (apical), posterior, inferior and anterior segments of the kidney. Only 10% of the blood goes to the renal medulla, and the majority (90%) goes to the cortex.

Structure of the renal artery

There are right and left renal arteries, each of which is divided into posterior and anterior branches, and these in turn are divided into segmental branches.

Segmental branches branch into interlobar branches, which break up into a vascular network consisting of arcuate arteries. From the arcuate arteries to renal capsule interlobular and cortical arteries depart, as well as medullary branches, from which blood flows to the lobes (pyramids) of the kidney. Together they form arches from which afferent vessels extend. Each afferent vessel branches into a tangle of capillaries, surrounded by a glomerular capsule and the base of the renal tubule.

The efferent artery also breaks up into capillaries. The capillaries weave around the tubules of the kidneys and then pass into the veins.

The right artery from the aorta runs forward and straight, and then goes to the kidney, obliquely and downwards, behind the inferior vena cava. The path of the left artery to the renal hilum is much shorter. It moves horizontally and behind the left renal vein flows into the left kidney.

Renal artery stenosis

Stenosis is the partial occlusion of an artery or its main branches. Stenosis develops as a result of inflammation or compression of the artery by a tumor, dysplasia or atherosclerotic narrowing of the vessel. Fibromuscular dysplasia is a group of injuries in which thickening of the middle, inner or subadventitial membranes of the vessel occurs.

With renal artery stenosis, the functioning of the kidney is impaired due to its inadequate blood supply. Impaired kidney function often leads to the development of renal failure. Renal artery stenosis sometimes manifests itself in a sharp increase in blood pressure. But most often this disease is asymptomatic. Long-term arterial stenosis can lead to azotemia. Azotemia manifests itself in confusion, weakness, and fatigue.

The presence of stenosis is usually determined using CT angiography, Dopplerography, urophragy, and arteriography. Additionally, to identify the causes of the disease, urine analysis, biochemical and general tests blood, determine the concentration of electrolytes.

To reduce blood pressure due to stenosis, a combination of antihypertensive drugs is usually prescribed. medicines with diuretics. When the lumen of the vessel is narrowed by more than 75%, it is used surgical methods treatment - balloon angioplasty, stenting.

Denervation of the renal arteries

To achieve a stable antihypertensive effect, endovascular surgeons use the method of catheter sympathetic denervation of the renal arteries.

Renal artery denervation is an effective bloodless technique for the treatment of resistant hypertension. During the procedure, a catheter is inserted into the patient's femoral artery and threaded into the arteries. Then, under short-term anesthesia, radiofrequency cauterization of the artery mouths is performed from the inside. Cauterization destroys the connection of the afferent and efferent sympathetic nerves of the arteries with nervous system, which leads to a weakening of the influence of the kidneys on indicators blood pressure. After cauterization, the conductor is removed and the puncture site femoral artery closed with a special device.

After denervation, there is a stable decrease in blood pressure by 30–40 mmHg. Art. throughout the year.

Renal artery thrombosis

Renal artery thrombosis is the blocking of renal blood flow by a thrombus detached from extrarenal vessels. Thrombosis occurs due to inflammation, atherosclerosis, and injury. In 20-30% of cases, thrombosis is bilateral.

With thrombosis of the renal artery, acute and strong pain in the lower back, kidney, back, which spreads to the stomach and side.

In addition, thrombosis can cause a sudden significant increase in blood pressure. Very often, with thrombosis, nausea, vomiting, constipation appear, and body temperature rises.

Treatment of thrombosis is complex: anticoagulant treatment and symptomatic therapy, surgery.

Renal artery aneurysm

A renal artery aneurysm is a sac-like expansion of the lumen of the vessel due to the presence of elastic fibers in its wall and the absence of muscle fibers. An aneurysm is most often unilateral. It can be placed either intrarenally or extrarenally. Clinically, this pathology can manifest itself as vascular thromboembolism and arterial hypertension.

For renal artery aneurysm, surgery is indicated. There are 3 types of surgery for this type of anomaly:

artery resection;
excision of the aneurysm with replacement of its defect with a patch;
aneurysmography - suturing the arterial wall with aneurysm tissue left after preliminary excision of its main part.

Aneurysmography is used for multiple vessel lesions and large aneurysms.

The structure of the kidney vessels

The renal arteries arise from the abdominal aorta just below the superior mesenteric artery - at the level of the second lumbar vertebra. Anterior to the renal artery is the renal vein. At the hilum of the kidney, both vessels are located anterior to the pelvis.

The RCA passes behind the inferior vena cava. The LPV passes through the “tweezers” between the aorta and the superior mesenteric artery. Sometimes a ring-shaped LPV occurs, in which case one branch is located in front and the other behind the aorta.

Click on pictures to enlarge.

To study the vessels of the kidney, a 2.5-7 MHz convex sensor is used. The patient is positioned supine, the sensor is placed in the epigastrium. Assess the aorta from the celiac trunk to the bifurcation in B-mode and color flow. Trace the course of the RAA and LPA from the aorta to the renal hilum.

Drawing. In the CD mode, on the longitudinal (1) and transverse (2) sections, the RAA and LPA extend from the aorta. The vessels are directed to the gates of the kidney. Anterior to the renal artery is the renal vein (3).

Drawing. The renal veins drain into the inferior vena cava (1, 2). The aortomesenteric “tweezers” may compress the left ventricular vein (3).

Drawing. At the hilum of the kidney, the main renal artery is divided into five segmental ones: posterior, apical, superior, middle and inferior. The segmental arteries are divided into interlobar arteries, which are located between the pyramids of the kidney. The interlobar arteries continue into the arcuate → interlobular → glomerular afferent arterioles → capillary glomeruli. Blood from the glomerulus drains through the efferent arteriole into the interlobular veins. The interlobular veins continue into the arcuate → interlobar → segmental → main renal vein → inferior vena cava.

Drawing. Normally, with CDK, the renal vessels are traced to the capsule (1, 2, 3). The main renal artery enters through the renal hilum; accessory arteries from the aorta or iliac artery may approach at the poles (2).

Drawing. Ultrasound of a healthy kidney: along the base of the pyramids (corticomedullary junction) linear hyperechoic structures with a hypoechoic track in the center are identified. These are arcuate arteries, which are mistakenly regarded as nephrocalcinosis or stones.

Video. Arc-shaped arteries of the kidney on ultrasound

Doppler of renal vessels is normal

The normal diameter of the renal artery in adults is 5 to 10 mm. If diameter<4,65 мм, вероятно наличие дополнительной почечной артерии. При диаметре главной почечной артерии <4,15 мм, дополнительная почечная артерия имеется почти всегда.

The renal artery should be assessed at seven points: at its exit from the aorta, in the proximal, middle and distal segments, as well as the apical, middle and lower segmental arteries. We evaluate peak systolic (PSV) and end-diastolic (EDV) blood flow velocities, resistivity index (RI), acceleration time (AT), acceleration index (PSV/AT). See more details.

The normal spectrum of the renal arteries has a pronounced systolic peak with antegrade diastolic flow throughout the cardiac cycle. In adults, the normal PSV on the main renal artery is 100±20 cm/sec, EDV is 25-50 cm/sec, in young children PSV is 40-90 cm/sec. In segmental arteries, PSV drops to 30 cm/sec, in interlobar arteries to 25 cm/sec, in arcuate arteries to 15 cm/sec and interlobular arteries to 10 cm/sec. RI at the renal hilum<0,8, RI на внутрипочечных артериях 0,34-0,74. У новорожденного RI на внутрипочечных артериях достигает 0,8-0,85, к 1 месяцу опускается до 0,75-0,79, к 1 году до 0,7, у подростков 0,58-0,6. В норме PI 1,2-1,5; S/D 1,8-3.

Drawing. Normal spectrum of renal arteries - high peak systolic, antegrade diastolic flow, low peripheral resistance - RI normal<0,8.

Drawing. The spectrum of renal vessels in newborns: renal artery - pronounced systolic peak and antegrade diastolic flow (1); high resistance in the intrarenal arteries is considered normal for newborns - RI 0.88 (2); renal vein - antegrade flow with a constant speed throughout the entire cardiac cycle, minimal respiratory fluctuations (3).

Doppler for renal artery stenosis

Renal artery stenosis can be found in atherosclerosis or fibromuscular dysplasia. With atherosclerosis, the proximal segment of the renal artery is most often affected, and with fibromuscular dysplasia, the middle and distal segments are most often affected.

Direct signs of renal artery stenosis

The aliasing indicates the location of the turbulent high-speed flow where measurements should be made. In the area of stenosis PSV >180 cm/sec. In young people, the aorta and its branches may normally have a high PSV (>180 cm/sec), while in patients with heart failure, the PSV is low even in the area of stenosis. These features are leveled by the renal-aortic ratio RAR (PSV in the area of stenosis/PSV in the abdominal aorta). RAR for renal artery stenosis >3.5.

Indirect signs of renal artery stenosis

Direct criteria are preferable; diagnosis should not be based solely on indirect signs. In the post-stenotic region, the flow attenuates - tardus-parvus effect. In renal artery stenosis on the intrarenal arteries, PSV is too late (tardus) and too small (parvus) - AT >70 ms, PSV/AT<300 см/сек². Настораживает значительная разница между двумя почками — RI >0.05 and PI >0.12.

Table. Criteria for renal artery stenosis on ultrasound

Drawing. A 60-year-old female patient with refractory arterial hypertension. PSV on the abdominal aorta 59 cm/sec. In the proximal part of the RAA with CDK aliasing (1), PSV is significantly increased 366 cm/sec (2), RAR 6.2. In the middle segment of the PPA with CDK aliasing, PSV 193 cm/sec (3), RAR 3.2. On segmental arteries without a significant increase in acceleration time: upper - 47 ms, middle - 93 ms, lower - 33 ms. Conclusion:

Drawing. Patient with acute renal failure and refractory arterial hypertension. Ultrasound of the abdominal aorta and renal arteries is difficult due to gas in the intestines. On the segmental arteries on the left RI is about.68 (1), on the right RI is 0.52 (2), the difference is 0.16. The spectrum of the right segmental artery has a tardus-parvus shape - acceleration time is increased, PSV is low, the apex is rounded. Conclusion: Indirect signs of stenosis of the right renal artery. CT angiography confirmed the diagnosis: at the mouth of the right renal artery there are atherosclerotic plaques with calcification, moderate stenosis.

Drawing. Patient with arterial hypertension. PSV in the aorta is 88.6 cm/sec (1). In the proximal part of the RPA there is aliasing, PSV 452 cm/sec, RAR 5.1 (2). In the middle section of the PPA there is aliasing, PSV 385 cm/sec, RAR 4.3 (3). IN distal section PSA PSV 83 cm/sec (4). On the intrarenal vessels tardus-parvus the effect is not determined, on the right RI is 0.62 (5), on the left RI is 0.71 (6), the difference is 0.09. Conclusion: Stenosis in the proximal part of the right renal artery.

Doppler of renal veins

The left renal vein passes between the aorta and the superior mesenteric artery. The aortomesenteric “tweezers” can compress the vein, leading to venous renal hypertension. In a standing position, the “tweezers” compress, and in a lying position, they open. With Nutcracker syndrome, outflow through the left testicular vein is difficult. This is a risk factor for the development of left-sided varicocele.

Due to compression, the spectrum of the left vein is similar to the portal vein - spectrum above the baseline, constant low speed, contour in smooth waves. If the ratio of the diameter of the left vein in front of and in the narrowing zone is more than 5 or the flow rate is less than 10 cm/sec, we conclude that the venous pressure in the left kidney is increased.

Task. On ultrasound, the left renal vein is dilated (13 mm), the area between the aorta and the superior mesenteric artery is narrowed (1 mm). Blood flow in the area of stenosis at high speed (320 cm/sec), reverse blood flow in the proximal segment. Conclusion: Compression of the left renal vein by aortomesenteric “tweezers” (Nutcracker syndrome).

Compression of the renal vein is possible due to its abnormal location behind the aorta. The diameter ratio and flow rate are evaluated according to the above rules.

The nature of the blood flow in the right renal vein approaches that of the caval vein. The shape of the curve changes when you hold your breath and can be flatter. Blood flow speed is 15-30 cm/sec.

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