Aneurysms are pretty uncommon to most of us. It might come out as a surprise when diagnosed with one. It simply doesn’t give any warning signs. To be more clear, it is an incidental finding. Let us get to know about these silent time bombs in this article.
Aneurysms are basically dilations of the blood vessels. Increased stress to the vessel wall causes these dilations. In simple words, it is the bulging or ballooning of the arteries.
HOW DO ANEURYSMS DEVELOP?
Arteries are basically blood vessels that carry oxygen-rich blood from the heart to the other parts of the body. As we already read in the previous lines, there is an increase in stress to the blood vessel walls. This increased stress in turn weakens the vessel wall. In addition, this may cause an outpouching of the vessel wall. Further, this abnormal dilation of the vessel wall causes an aneurysm.
Aneurysms especially the cerebral type tend to occur around a weak spot. These weak spots develop as a result of,
- Brain injury
- Congenital defects
The circle of Willis is the main region of formation of weak spots. The circle of Willis is nothing but a confluence of blood vessels that are found at the base of the brain. Several arteries join together at the base of the brain to form this structure. It provides collateral circulation to the anterior and posterior regions of the brain. It provides almost 80% of the blood supply to the cerebrum.
The weak spots usually forms at the region where arteries branch out. The pressure of blood flowing through the arteries pressurises the weak spot. This constant blood pressure in the arteries causes the weak spot to balloon out and form a bulge. This is how a cerebral aneurysm develops. Also known as a circular or berry aneurysm. Let us look at some common underlying aneurysm triggering factors.
1. HAEMO-DYNAMIC STRESS:
Aneurysms may grow and push the nearby brain tissue or nerves. Also, blood from the aneurysm may leak if the walls get too thin. Moreover, it can burst and spill the high-pressure blood into the space around the brain pressurising the brain tissue and causing injury to the cells of the brain. Further, chemicals in the escaped blood irritate brain arteries and cause narrowing, leading to brain swelling and increased intracranial pressure. This causes serious brain injury.
Smoking is a major risk factor for aneurysms. Chronic smokers have a greater risk of developing aneurysms. These types of aneurysms are more likely to rupture. The reason behind this is the blood volume and the thickness of the blood (viscosity) that is created due to smoking. Other mutual additions like consuming way more alcohol along with smoking speeds up the process.
High blood pressure is also a major risk factor of aneurysm. Stress further aggravate this condition. Kidney diseases paired with hypertension is also a major risk factor.
Unlike occlusive diseases, an aneurysm has a genetic factor. Further, they tend to run in families. Gender also greatly influences the likelihood of rupture of the aneurysm. Females have a greater tendency for rupturing of aneurysms than their male counterparts.
Once an aneurysm becomes 10 mm or more it is more likely to rupture.
GENETIC AND GENERAL CONDITIONS THAT PREDISPOSE TO ANEURYSM:
Certain genetic condition and general body conditions and syndromes have a higher likelihood to predispose a patient to aneurysms. These include,
1. POLYCYSTIC KIDNEY DISEASE (PKD):
When a person has existing PKD, they are more likely to get aneurysms all over the body. It is an inherited disorder that causes a lot of cysts primarily in the kidney. This causes your kidney and gradually over a period of time the kidney loses its function.
However, these are non-cancerous and these sacs mostly contain fluid. They vary in size greatly and can grow to a large extent.
Studies show that comparatively people with PKD have a 5 fold greater risk of developing aneurysms than general population.
2. CONNECTIVE TISSUE DISORDERS:
Connective tissue disorders like osteogenesis imperfecta, Marfan’s syndrome, Ehler’s-Danlos syndrome also predispose a person greatly to aneurysms.
This is an age-related disease. Plaque deposits mainly that of fat, cholesterol, calcium and other substances build up in the walls of the arteries. Over time they harden and narrow the blood vessels and restrict blood flow.
When these plaques rupture they form small blood clots called thrombus that further block the arteries limiting oxygen-rich blood flow to organs and tissues.
Hence, atherosclerosis could also cause aneurysms.
For having an easy and good understanding, we should have some idea of the layers of the blood vessels. Basically, there are 3 layers of blood vessels they are,
- Tunica intima (Innermost layer of the blood vessel)
- Tunica media (Intermediate or the middle layer between intima and adventitia)
- And the tunica adventitia (Outermost layer of the blood vessel)
Aneurysms can be broadly divided into 2 types as,
- True aneurysm
- False aneurysm
This broad and rough classification is generally based on the number of layers that causes the outpouching of the vessel wall
The most commonplace for the occurrence is the aorta. Also, it is the main artery that runs from the heart through the chest and abdomen. Further, not only the aorta but aneurysms can also occur in the arteries of the brain, heart and other parts of the body.
Further, if an aneurysms grows large and uncontrollably it can burst suddenly and can cause death of the victim.
SYMPTOMS OF ANEURYSMS:
Aneurysms can develop and become large before they show any symptoms. This makes them extremely dangerous. If detected and treated early aneurysms have a better prognosis. Also, it is important to understand that the symptoms and presentation change according to the location of the artery and the blood vessel that the aneurysm develops in.
This is one of the most common locations for the development of an aneurysm.
- The patient can have the very worse kind of headache they have ever experienced. Further, it could be sudden and severe (Thunderclap headache).
- Vision problems are common
- Nausea and vomiting
- Stiffness and pain in the neck region
- Mental confusions
- Aneurysms might cause strokes
- Apart from these, sub-arachnoid bleeding and intra cranial bleeding are very common.
SYMPTOMS OF AN UN ERUPTED CEREBRAL ANEURYSMS:
- Headache or pain behind any one of the eyes
- Drooping eyelids or vision problems
- Further, weakness or numbness on one side of the face.
The most common site of non-specific aneurysm is the infra-renal abdominal aorta.
In cases of abdominal aneurysms the pain mostly presents in the
- Central abdomen
- Loin or groin region
- The iliac fossa
Aneurysms can be pretty tricky to detect. Most of the aneurysms are incidental findings. Usually seen on,
- Physical examination
- Plain X-ray
- And most commonly on abdominal ultrasound (in case of abdominal aneurysm)
- But, family history and symptoms play a major role. Once, a patient meets general criteria for having an aneurysm through a specially designed questionnaire, an MRA (Magnetic resonance angiogram) can be taken.
A MRA shows the arteries of the brain. There is no radiation, no dye used. This can tell us whether there is an aneurysm.
Firstly, in cases of a ruptured aneurysm surgery is the only option of treatment. Further, a ruptured aneurysm is a medical emergency. A ruptured aneurysm includes surgical options like,
- Endo vascular coiling
- Surgical clipping
The surgeon decides the stream of treatment based on the emergency, type of aneurysm and location of the aneurysm.
ENDO VASCULAR COILING:
Endo vascular coiling is an option of treatment mainly in case of abdominal or lower body aneurysms. In endovascular coiling, the surgeon inserts a large plastic tube called a catheter into the artery. This tube is inserted through the artery. Further, the catheter is advanced till it reaches the aneurysm. Imaging devices check the advancing of the catheter into the artery.
After reaching the catheter reaches the aneurysm the coil in the catheter is released into the aneurysm. Over time, a blood clot forms over the coil, thus cutting off the aneurysm and preventing further damage.
Surgical clipping is done in cases of cerebral aneurysm. In this procedure, a small opening is made by removing a piece of bone from the skull. This opening is made near the location of the aneurysm. Once the aneurysm is reached a small metal clip-like device clip off the erupted aneurysm. The clip is placed at the base of the aneurysm (the stem) that connects the aneurysm to the artery. This prevents the flow of blood from the artery to the aneurysm.
UN ERUPTED ANEURYSMS:
After confirming the aneurysm through imaging modalities, depending on the size and location of the aneurysm, the treatment is decided.
If the aneurysm is un erupted but might be a potential threat either an endo vascular coiling or surgical clipping has to be performed. If the aneurysm is small, the patient might be kept under constant observation over a period of time before performing either of these procedures.
REDUCING RISK OF DEVELOPING ANEURYSMS:
As we already saw, aneurysms rarely show symptoms. When they show symptoms it might be too late to treat them. Therefore, the best way to battle this condition is prevention. And, the only way to prevent an aneurysm is by maintaining a healthy lifestyle.
- If you are a person who has high blood pressure or cholesterol, regular exercise, medications and diet modifications can be of great help in preventing aneurysms.
- Try quitting smoking and consume alcohol only in moderation. However, preventing or avoiding these habits is the best thing for a healthy lifestyle.
- People who are at a higher risk from the aforementioned conditions or syndromes can get a regular evaluation from their physician just to be on a safer side.
To sum up, aneurysms are quite risky. Hence, to stay away from these follow a healthy lifestyle. Get regular general health checkups. Even a small heads-up can go a long way in saving our lives.