Renal arteriosclerosis, also known as renal artery stenosis in technical terms, is a type of arteriosclerosis in which one or both renal arteries are narrowed. If left untreated, the condition can, at worst, lead to kidney failure and thus become life-threatening.
What is renal arteriosclerosis?
By renal arteriosclerosis, physicians understand, as the name suggests, a calcification of the renal arteries. In this case, either one or both arteries become narrowed and in this way impair the blood flow. Renal arteriosclerosis can either be a trigger for other diseases or can occur itself as a secondary disease. In most cases, renal artery stenosis is directly related to high blood pressure. It can either precede it or occur later as a consequence of high blood pressure. Heart disease can also be related to renal artery stenosis, especially coronary artery disease or arterial occlusive disease, for example.
Causes
According to statistics, the causes of renal arteriosclerosis in about 80% of cases are a generally present calcification of the arteries in the body. This is caused by deposits in the vessels, which are promoted by an unhealthy lifestyle. If fat and cholesterol are consumed in large quantities and over a period of years, they are deposited on the inner walls of the vessels and thus lead to a slow narrowing. As a result of this, among other things, there is an increase in high blood pressure. This process usually takes place in various parts of the body and can thus also affect the renal arteries. Risk factors that promote renal artery calcification include diabetes, smoking, high cholesterol, lack of exercise and stress.
Symptoms; complaints and signs
Renal arteriosclerosis (renal artery stenosis) causes the renal arteries to narrow, resulting in an undersupply of blood to the kidneys. To prevent this, there is a release of hormones that increase blood pressure. Therefore, the main symptom of renal artery stenosis is initially high blood pressure. Initially, renal artery stenosis goes unnoticed. Both high blood pressure and renal artery stenosis do not form symptoms initially. Later, high blood pressure can cause such non-specific symptoms as dizziness, nausea, morning headaches, nervousness or visual disturbances. Sometimes so-called blood pressure crises also occur. Blood pressure crises are characterized by sudden phases of high blood pressure. In these hypertensive phases, pulmonary edema, decreasing physical capacity and severe shortness of breath often occur. During blood pressure crises, the second (diastolic) blood pressure value increases in isolation, while the first (systolic) blood pressure value remains unchanged. In the long term, the chronically high blood pressure and the constant hypertension crises damage the kidney tissue to the point of kidney insufficiency. The affected kidney shrinks and forms a shrunken kidney. To compensate, the healthy kidney enlarges. Thereafter, all the symptoms of progressive kidney failure occur. After an initial increase in urine output, the amount of urine excreted decreases in later stages of kidney disease. In addition to fatigue and decreased performance, pain in the kidney area, headache, edema, excruciating itching, nausea, vomiting, bad breath of ammonia, and more then occur.
Diagnosis and course
If renal arteriosclerosis is suspected, the treating physician will first measure blood pressure. A significantly elevated diastolic value may indicate calcification. Additional blood and urine tests provide further information about the patient’s state of health, as does an ultrasound of the kidney region. A detailed discussion of the patient’s medical history and lifestyle can also help to establish a diagnosis. A hissing sound may be heard when listening to the kidney region with a stethoscope. If renal artery stenosis is detected early, it can usually be treated well before permanent damage to the kidneys occurs. If renal artery stenosis has already occurred, the prognosis depends on the degree of damage.
Complications
In most cases, renal arteriosclerosis (renal artery stenosis) can be treated well with a variety of methods.However, if left untreated, the disease will progress. This may result in numerous complications. Due to the narrowing of the renal arteries, the kidneys are initially undersupplied with blood. In order to maintain a normal blood supply, a signal is sent that causes a general increase in blood pressure in the body. As a result, chronic hypertension develops. In addition, the renal artery may become completely blocked. As a result, chronic renal failure requiring dialysis is imminent. Detoxification of the blood can then no longer take place sufficiently without regular blood washing. Urinary substances are released into the bloodstream, where they can lead to a wide range of damage to various organs. In extreme cases, this can lead to multiple organ failure with a fatal outcome. But chronic high blood pressure can also lead to many secondary diseases, particularly affecting the cardiovascular system. The risk of heart attacks or strokes increases. However, even treatment of renal artery stenosis does not lead to success in every case. For example, blood pressure normalizes in about 75 percent of cases of fibromuscular renal artery stenosis. However, if it has been caused by arteriosclerosis, success may sometimes not be achieved. Furthermore, even after successful surgery, there remains a residual risk of reocclusion of the blood vessel.
When should you see a doctor?
Elevated blood pressure, gastrointestinal symptoms, and shortness of breath indicate renal artery calcification. Anyone who notices the symptoms described should consult a doctor. If the symptoms persist for more than two to three days or become more severe within a short time, medical advice must be sought immediately. Calcification of the renal arteries can usually be treated well, provided it is detected at an early stage. The physician will determine the condition by means of a physical examination and subsequently initiate treatment. People who have an unhealthy lifestyle or suffer from kidney disease are among the risk groups and must discuss the typical symptoms with their family doctor. People with hormonal or arterial complaints are also best advised to consult a general practitioner. Other points of contact are the nephrologist and other specialists for internal diseases. After the initial diagnosis by the specialist, further treatment is usually carried out by the general practitioner. Hospitalization is only necessary for serious complications such as severe kidney pain or blood in the urine.
Treatment and therapy
Once the attending physician has diagnosed renal arteriosclerosis, appropriate therapy must be initiated. In many cases, the disease can be treated quite well by dilating the abnormally narrowed arteries. This is done with the aid of a balloon catheter, which is pushed through the bloodstream to the narrowed area. There, a balloon is inflated so that the artery is widened again and the blood can flow at a normal rate. If necessary, it may be necessary for this procedure to take place in several places or even repeatedly. Especially if the renal arteriosclerosis is caused by permanently elevated blood pressure, the arteries can narrow again relatively quickly. If this type of treatment does not bring about any improvement, it is possible to perform a vascular operation in which a so-called bypass is inserted. The narrowed artery can thus be bypassed and regular blood flow restored. In addition, the attending physician can prescribe medication to lower blood pressure. However, the kidney function must always be checked, as the medication can have a negative effect on it. A healthy lifestyle also helps to improve the condition of the arteries and general health, and should therefore be adhered to in order to prevent the worsening of renal arteriosclerosis.
Outlook and Prognosis
People with renal artery calcification are in a life-threatening condition. The general well-being deteriorates continuously until the organism collapses. Without medical care and medical monitoring, the affected person is at risk of sudden premature death. Organ failure occurs, with ultimately no prospect of recovery. In acute cases, an emergency physician must be called so that life-prolonging measures can be initiated.For a good prognosis, it is crucial that a diagnosis is made as soon as the first irregularities and health impairments occur. Medical treatment is then initiated as quickly as possible. This is the only way to avoid an emergency situation and optimize the blood supply. In addition to organ failure of the kidneys, the affected person is also at risk of functional disorders of the heart. If other disorders of the circulatory system or cardiac activity are present, the prospect of recovery is vanishingly small. Nevertheless, with early treatment, stabilization of the organism can be initiated so that the patient can continue to live. Long-term therapy and regular check-ups are necessary to achieve relief. In many cases, the disease and the resulting health impairments cause severe emotional stress. Psychological sequelae may occur, contributing to further deterioration of overall health.
Prevention
Since the causes of renal arteriosclerosis in most cases lie in general arteriosclerosis, the prevention is to significantly minimize the risk factors if possible. In this context, smoking should be stopped and excess weight should be reduced. A low-fat and balanced diet has a positive effect on the arteries, as does regular exercise. If diseases such as diabetes, elevated cholesterol levels or high blood pressure already exist, these should be treated in any case so that renal artery calcification cannot develop in the first place.
Follow-up care
After stent implantation, regular use of anticoagulant medicine is necessary. A combination of aspirin (ASA) and clopidogrel (Plavix) is usually used for this purpose. While Plavix can usually be discontinued after several weeks, aspirin use is usually recommended for life. The drug aspirin reduces the risk of cardiovascular disease. Approximately four weeks after implantation, a further examination should be performed in the vascular surgery outpatient clinic and in the renal center. In the course of the examination, the renal artery is checked and the laboratory values are checked. In particular, arterial blood pressure and kidney values should be determined here. Further follow-up can be performed by the general practitioner or by renal specialists. Follow-up examinations should be performed at regular intervals in order to be able to detect various dysfunctions at an early stage. In the event of a suspected recurrence of the disease, further diagnostics should be performed as soon as possible. As a rule, the cause of renal artery stenosis can be successfully corrected – provided the disorder is recognized quickly and rapid steps are taken to treat it. This is because the longer the stenosis with high blood pressure has been untreated, the lower the chance of successfully lowering blood pressure. In addition, untreated renal artery stenosis is often associated with gradual loss of function and shrinkage of the kidney.
Here’s what you can do yourself
Often, renal artery stenosis is triggered by pre-existing arterial calcification in the body, which in turn is caused by permanently elevated blood pressure. To reduce high blood pressure and thus the risks of further calcification in the renal arteries, lifestyle changes are crucial in addition to drug treatment. To this end, it is important to reduce excess weight and avoid fatty and highly processed industrial foods, especially those containing saturated fatty acids, as they increase LDL cholesterol levels, which are considered dangerous. Saturated fatty acids are found in all animal products, but in large quantities especially in fast food, potato chips, pastries and confectionery. The diet should therefore be balanced and consist mainly of freshly prepared foods. Various studies have also demonstrated the positive effect of red wine on blood vessels, although consumption should be limited to a maximum of two glasses per day. In the case of existing renal arteriosclerosis, it is also advisable to refrain from smoking and to engage in physical activity. Sports such as swimming, cycling and Nordic walking, but above all walks in the woods, make sense, as they not only positively support the cardiovascular system, but have also been shown to help reduce stress.Reducing stress can also be achieved through regularly applied meditation, yoga, and adequate sleep.
