Renal artery stenosis is the narrowing of the artery supplying the kidneys, which leads to secondary hypertension and which can be treated in Turkey before it is too late, either by catheterization or surgery.
What is renal artery stenosis? renal artery stenosis ?
Renal artery stenosis is the narrowing of the artery that supplies the kidneys, either from one side or from both sides (ie, in one or both kidney arteries).
Stenosis occurs in 80 % cases due to hardening of the arteries, the main artery (aorta) and artery branching from it (kidney).
As a result, arterial hypertension caused by activation of the renin-angiotensin-aldosterone system can develop.
Therefore, renal artery stenosis is often accompanied by high blood pressure.
This affects most elderly smokers as well. Also, 20 % patients had congenital renal artery stenosis (especially women).
In this condition, stenosis of the renal arteries is caused by the muscles of the vessel wall and the structure of the connective tissue in the vessel.
A distinction is made between the following types of renal artery stenosis:
Atherosclerotic stenosis of the renal arteries:
Renal artery stenosis is caused by atherosclerosis. This type of renal artery stenosis is particularly common in older adults.
Fibromuscular stenosis of the renal artery:
In this form of the disease, the thickness of the vascular wall of the renal artery increases, thus narrowing the opening of the blood vessels. This form mainly affects young people.
In 1% to 5% of all cases, renal artery stenosis is the cause of hypertension.
Causes of narrowing of the renal arteries:
It is the most common cause of renal artery stenosis, accounting for 60% to 90% cases.
It mainly occurs at the junction between the aorta and the renal arteries.
fibromuscular dysplasia (fibromuscular dysplasia):
It is a change in the vascular connective tissue.
Renal artery stenosis is more common in young patients and most likely occurs in the middle third of the renal artery.
Such as Takayasu's arteritis (unspecified aortitis).
Other rare causes
Such as injuries or aneurysms of the renal artery or thrombosis.
The pathophysiology of renal artery stenosis may be explained by the Goldblatt effect. If the diameter of the renal artery is reduced to less than 40 percent, the blood flow in the kidney is reduced.
The kidneys react to reduced blood flow leading to increased release of renin, which via the renin-angiotensin-aldosterone system leads to vasoconstriction (vasoconstriction) and increased sodium and water reabsorption.
This results in an increase in systemic blood pressure.
In this way, the diseased kidneys try to improve the restricted blood flow, but they also increase the pressure in the body's circulation to values that are considered satisfactory.
Symptoms of renal artery stenosis:
It is not always necessary for the disease to have symptoms, but it can also go without symptoms.
However, vascular hypertension occurs in many cases. And
It is high blood pressure caused by kidney disease. Additionally, blood flow to the kidneys is reduced, which can lead to kidney impairment.
In general, possible symptoms include:
- High blood pressure (particularly diastolic blood pressure).
- Decreased effect of the biological clock on vital processes (that is, it does not correspond to the day-night cycle).
- A sound of narrowing in the umbilical region (in about 40 percent of patients).
- In advanced patients, high blood pressure values often develop rapidly.
Diagnosis of renal artery stenosis
In lean people, renal artery stenosis can be observed with a stethoscope.
During the physical exam, a flowing noise is heard in the abdomen and waist area, which indicates changes in the blood vessels of the kidneys.
Vascular change is primarily diagnosed by ultrasound examination of the kidneys and blood vessels.
During the examination, the rate of blood flow through the vessels and the width of the vessel can be measured.
If significant constriction can be detected with a low flow velocity, treatment is necessary.
X-rays are not used in the ultrasound examination, which is why it is especially convenient for the patient.
Another option is what is known as magnetic resonance angiography, in which the renal vessels are shown very precisely.
Here the patient is injected with a contrast medium intravenously, with which the renal vessels can be clearly visible.
Renal artery stenosis treatment
The following treatment options are available:
ACE inhibitors are used with beta-blockers as medicine. But when drug treatment fails, and when there is no improvement in blood pressure values, surgical procedures become an option.
NoticeableIn the case of renal artery stenosis of both kidneys or if only one kidney is present, treatment with ACE inhibitors can lead to acute renal failure and is not recommended in this case.
Interventional Therapy - Percutaneous Angioplasty (Percutaneous Angioplasty)PTA):
Percutaneous angioplasty (PTA) is successful in 80% renal artery stenosis, often with subsequent temporary tube implantation. as with Cardiac catheterizationA balloon is pushed into the renal artery through a catheter. This balloon is then expanded at the site of the defect to expand the vessel.
If necessary, a temporary intravascular tube may be used. The temporary tube is intended to ensure that the blood vessel remains open
PTA is only performed if pharmacological treatment of hypertension does not lead to an adequate decrease in pressure or if the artery is more than 70% occluded and therefore no improvement in hypertension is expected.
Surgical treatment - aortic surgery (anatomical) or anatomical bypass surgery
In rare cases, surgery may be necessary, for example, if catheter treatment is unsuccessful.
During surgery, the narrowed portion of the blood vessel is removed and, if necessary, attached to an artificial vascular tip.
The cause of renal artery stenosis can usually be corrected.
In most cases, a normal blood pressure level can be reached
. But the longer the stenosis remains untreated and the higher the blood pressure, the less chance the blood pressure will drop again, as the body adjusts to the high blood pressure over time.
If high blood pressure persists, what is called persistent high blood pressure occurs.
In addition, if renal artery stenosis is not treated, there is a risk of shrinkage of the kidney and a gradual loss of its function.
An unaffected kidney can then enlarge.
The most important frequently asked questions about the treatment of renal artery stenosis in Turkey:
Is renal artery stenosis considered life threatening?
Renal artery stenosis caused by fibromuscular dysplasia is fatal and may eventually lead to kidney failure.
How does renal artery stenosis cause high blood pressure?
Because your kidneys don't get enough blood, they respond by making a hormone that raises your blood pressure.
How common is renal artery stenosis?
It is estimated that some degree of renal artery stenosis (more than 50%) is present in about 18% of people aged 65-75 years and 42% of those aged over 75 years.
What are the treatment methods for renal artery stenosis in Turkey?
Treatment methods for renal artery stenosis in Turkey are either by catheterization or surgery.