Renovascular hypertension, also known as renal hypertension, is characterized by a narrowing of the arteries that transport blood to the kidneys. In reaction to not receiving the amount of blood they need, the kidneys will secrete a hormone that causes hypertension. When diagnosed in its early stages, renal hypertension is treatable.
Renovascular hypertension causes
Renal hypertension is caused by a narrowing in the arteries that provide blood to your kidneys. The body recognizes this lack of proper supply as dehydration and, as a consequence, releases a hormone that traps water and sodium. Then, blood vessels will fill up with this extra fluid, causing your blood pressure to rise.
When one or both arteries become narrow, this condition is known as renal artery stenosis. It can be caused by a condition known as atherosclerosis, which is characterized by hardened arteries.
Another cause for renovascular hypertension can be fibromuscular dysplasia, although it’s not that common. This condition reflects an abnormal structure of the renal arteries.
Renovascular hypertension symptoms
As with most other forms of hypertension, this one is also symptomless, unless it’s in a more advanced stage.
Preventively, you can pay attention to the following signs which may indicate renal hypertension:
- Hypertension which cannot be kept under control by at least three different medications.
- Fluctuations in blood pressure which occur suddenly.
- Sudden malfunctioning of the kidneys.
- Pulmonary edema, which is lung fluid build-up.
Renovascular hypertension diagnosis
The doctor could suspect that you suffer from renal hypertension by examining your current health state, as well as the result of your blood pressure test. If you suffer from another form of vascular diseases, you are more exposed to renal hypertension.
During consultation, doctors can listen to the belly or the neck in order to identify any narrow arteries. When blood flow is irregular, it can make a sound called a bruit, indicating a blood pressure more elevated than normal.
- A duplex ultrasound is an imaging test that reveals blockages in the renal artery. It can also determine if blood flows faster than normal in the nearby arteries. This ultrasound is a non-invasive test, but it isn’t always sufficient, as it cannot identify every case of renal artery stenosis. Also, it doesn’t provide any information on how much the arteries have narrowed, and sometimes takes a very skilled technician to identify all the details of this problem.
- Another imagining test which can be performed to identify renal hypertension is the CTA (short for “computerized tomographic angiography”). By using computer imaging and X-ray technology, this test involves injecting contrast medium in the patient’s veins, so that the artery structure can be more visible. The test doesn’t take very long, but there are people that may feel uncomfortable with it, as they lie down on a table which slides into the CTA machine, giving some people a sense of suffocation. However, there is no real suffocation threat, as this is mostly a psychological fear.
- MRA (short for “magnetic resonance angiogram) tests don’t use X-ray technology, but they can identify blood flow situation and give a clearer image on how the organs function. It still used contrast medium to make the artery structure more visible. Compared to a CTA test, an MRA involves sliding the patient into a much narrowed device, which could trigger claustrophobia.
- Catheter angiograms are more invasive X-ray tests, which involve sticking a flexible tube in the body, which has to reach the renal artery. The tube, which is called a catheter, is typically inserted through the groin. Some patients require muscle relaxer administration, for anxiety purposes. Contrast medium is also used, to expose the structure of the renal artery. While invasive and uncomfortable, this test is also very accurate, and offers the benefit of allowing doctors to dilate the blood vessels, if needed. Due to the discomfort caused by this procedure, it’s typically reserved for people that have tested positive for renal hypertension, and will require an immediate dilation of the blood vessels.
Renovascular hypertension treatment
People who have renovascular hypertension are prescribed meds for keeping blood pressure under control. The medication will depend on the patient’s state and bodily reaction, and will differ from one person to another. Because of that, these meds are not transmittable, meaning that if you take hypertension meds, you should never borrow them from, or lend to, someone else who suffers from the same condition.
In a lot of cases, patients are required to take several hypertension meds, which often include ACE inhibitors or angiotensin receptor blockers. People who have renal hypertension will require a medical consult about one or two weeks after starting their treatment with high blood pressure meds. Doctors will have to examine the kidney function and, if need be, adjust medication accordingly.
In some cases, a specialist may choose to perform an angioplasty which, as described above, is an invasive procedure that involves inserting a catheter into the renal artery, and dilating it. Angioplasty can be performed with either a balloon or a stent:
- The narrow vessels can be dilated with the help of a balloon, which is inflated inside the artery to help widen it. The balloon is deflated and removed, alongside the catheter, once the procedure is finished.
- A stent, on the other hand, is permanently inserted inside the blood vessels, keeping the artery open at all times.