High blood pressure is a very common problem. Especially among the elderly and middle-aged people. There can be many causes of hypertension. Among them - heart disease, kidney disease, endocrine disorders. As you know, increased pressure can lead to stroke and heart attack. To understand how to deal with this symptom, it is necessary to establish the cause. In some cases, hypertension occurs against the background of such a pathology as renal artery stenosis. To begin treatment of this disease should be as early as possible. After all, arterial stenosis can lead not only to an increase in blood pressure, but also to other serious consequences. Pathology occurs both in men and among the female population. In some cases, the disease is congenital. More often it occurs against a background of vascular disorders.
More on Renal Artery Stenosis
Renal artery stenosis is a narrowing of the lumen of a vessel, due to various pathological conditions. The disease is attributed to nephropathic pathologies. Renal arteries are large vessels that supply blood to organ tissue. With stenosis, they noticeably decrease in diameter. As a result, the blood supply to the kidneys is disrupted. This pathology leads to such serious disorders as secondary arterial hypertension, chronic renal failure. There are 2 mechanisms for the development of stenosis. Among them:
- Atherosclerotic option. It is observed in most patients suffering from this pathology. A similar mechanism for the development of stenosis is the gradual blockage of the lumen of the vessel with cholesterol plaques. Often severe vessel occlusion is noted in old age.
- Fibromuscular dysplasia. This option for the development of pathology is less common. It can occur in middle-aged women, as well as among young girls. Muscle dysplasia is a hereditary birth defect.
Only after instrumental examination can a diagnosis of renal artery stenosis be established. ICD is a classification of pathologies used throughout the world. It includes many diseases, each of which has a specific code. Renal artery stenosis is encoded in 2 ways, depending on the cause of its occurrence. One option is the code I15.0, which means "renovascular hypertension." Another ICD code is Q27.1. It stands for "congenital stenosis of the renal artery." Both conditions require treatment by a urologist or vascular surgeon.
Renal Artery Stenosis: Causes of Pathology
The narrowing of the lumen of the peripheral arteries is referred to the pathology of the vascular system. There are various causes of stenosis. The most common of these is atherosclerosis. As you know, in most cases it is observed in people who are overweight, leading a sedentary lifestyle or suffering from diabetes. Atherosclerosis can develop over time. However, it is rarely diagnosed until symptoms of clogged arteries appear. Other causes of stenosis include:
- Fibromuscular dysplasia. This term refers to a congenital genetic defect that results in a lack of muscle fibers in the vessel wall. Pathology is observed in women of any age.
- Aneurysm of the arteries of the kidneys.
- Tumors of the peripheral vessels.
- Congenital and acquired vasculitis.
- Compression of the renal artery by neoplasms originating from tissues of neighboring organs.
The listed reasons are found in rare cases. Therefore, their diagnosis is started only after the exclusion of atherosclerosis.
The mechanism of hypertension
The main symptom of stenosis of the arteries of the kidneys is an increase in blood pressure. Therefore, with this clinical syndrome, an examination of the renal system is necessary. How are renal artery stenosis and hypertension related? 2 mechanisms are involved in increasing blood pressure:
- Activation of the renin-angiotensin system. Under the influence of these biological substances, narrowing of the arterioles develops. As a result, peripheral vascular resistance increases. Thus, blood pressure in the arteries rises.
- Action of aldosterone. This hormone is produced in the adrenal cortex. Normally, it is constantly present in the body. However, with artery stenosis, its production increases. Due to the excessive amount of aldosterone, fluid and sodium ions accumulate in the body. This, in turn, also causes an increase in blood pressure.
As a result of chronic hypertension, changes occur on the part of the cardiovascular system. The left ventricle gradually hypertrophies and stretches. This is another cause of hypertension.
Renal Artery Stenosis: Symptoms of the Disease
Narrowing of the arteries of the kidneys leads to many consequences. Symptoms of stenosis do not appear immediately, but only with severe occlusion. At the same time, conservative treatment is not always effective. In addition to vascular disorders, arterial stenosis leads to ischemic changes in the kidney. As a result, the filtration and concentration function of the organ suffers. Given this, we can distinguish 2 clinical syndromes that develop with stenosis. The first is arterial hypertension. This syndrome is characterized by a number of clinical manifestations. Among them:
- High blood pressure. It can be either episodic or permanent. Of particular importance for the diagnosis is an increase in diastolic blood pressure (more than 100 mm Hg).
- The appearance of tinnitus.
- Dizziness.
- Nausea that has nothing to do with eating.
- Flickering of "flies" before the eyes.
- Headache in the temples, forehead.
- Irritability.
The second clinical syndrome is ischemic nephropathy. Due to impaired renal blood flow, the ânutritionâ of the organ ceases. Especially dangerous is bilateral renal artery stenosis. Hypertension is a condition that can be partially controlled with medications. Unfortunately, expressed organ ischemia cannot be corrected using drugs. Symptoms of âoxygen starvationâ of the kidney include: pain in the lower back, changes in urination. Often there is a decrease in the amount of fluid released, general weakness. An admixture of blood, a cloudy precipitate may appear in the urine.
Diagnostics
Only after examination can a diagnosis of renal artery stenosis be made. Diagnosis of the pathology includes the collection of complaints and medical history, laboratory tests and instrumental methods. Most often, the leading syndrome is arterial hypertension, a poor response to antihypertensive therapy. Also, patients may complain of discomfort in the lower back (on one or two sides), a change in the nature of urination. The survey plan includes:
- KLA and urinalysis.
- ECG.
- Blood chemistry. The disease can be suspected with an increase in creatinine and urea.
- Ultrasound of the kidneys.
- Special tests: urine analysis according to Nechiporenko, Zimnitsky.
- X-ray contrast study of blood vessels - renography.
- Dopplerography of the renal arteries.
- Angiography.
- CT and MRI.
Differential diagnosis
Given the fact that hypertensive syndrome is leading, renal artery stenosis is differentiated from cardiac pathologies, aortic atherosclerosis. Symptoms may also resemble Itzingo-Cushing's disease and pheochromocytoma.
If signs of ischemic nephropathy prevail, then stenosis is differentiated with inflammatory pathologies of the kidneys. These include pyelo- and glomerulonephritis. Also, similar symptoms can be observed with a complication of diabetes.
Conservative therapy for renal artery stenosis
Treatment of renal artery stenosis begins with conservative methods. With hypertension caused by narrowing of the renal vessels, a combination of several drugs is necessary. Angiotensin converting enzyme inhibitors are preferred. But these drugs are not recommended for use with severe atherosclerotic vascular lesions. The combination consists of the following groups of medicines:
- Beta blockers. These include drugs âMetoprololâ, âCoronalâ, âBisoprololâ.
- Loop diuretics. The drug of choice is the medicinal substance Furosemide.
- Calcium channel blockers. Among them are medicines âVerapamilâ, âDiltiazemâ.
In addition, the patient should take the drugs necessary for the treatment of the underlying disease (atherosclerosis, diabetes mellitus).
Surgical treatment of stenosis
Unfortunately, in most cases, antihypertensive therapy is ineffective. In addition, a decrease in blood pressure only exacerbates ischemic nephropathy. Therefore, you have to resort to surgery. Depending on the extent of the lesion, the method of surgical treatment is chosen. Most often, stenting of the artery supplying the kidney is performed. If the entire lumen of the vessel is obturated for a large extent, shunting is performed - replacing the portion of the vessel with the graft. With the death of renal tissue, a nephrectomy is performed.
Prognosis after surgical treatment of stenosis
Regardless of which side the lesion was (stenosis of the left renal artery or the right), the prognosis after surgery depends on the recommendations of the doctor and the patient's physical condition. Often, surgical treatment can achieve a positive result. After a few months, normalization of blood pressure occurs in 60-70% of patients.
Complications of Renal Stenosis
Unfortunately, stenosis of the arteries of the kidneys is diagnosed only at a late stage of development. Therefore, you can not neglect the recommendations of a doctor. Indeed, without proper treatment, terrible complications can develop. Among them - myocardial infarction and stroke in the presence of a hypertensive crisis, acute and chronic renal failure. If surgery is not performed on time, the patient may lose an organ.
Prevention
Preventive measures include constant monitoring of blood pressure in the presence of complaints of dizziness and tinnitus, smoking cessation and alcohol. To avoid the progression of atherosclerosis, it is necessary to follow a special hypocholesterol diet, lead an active lifestyle. Some patients should take special medications - statins.