What is a Brain Aneurysm?
Aneurysm is a ballooning that occurs as a result of weakening of the arterial wall in the brain and is often seen in the bifurcation areas of the vessels. This ballooning structure is more unstable than a normal vessel, and under some conditions, it can rupture and cause bleeding into the brain, threatening life. Aneurysms may be due to congenital vascular malformations, or they may develop after high blood pressure, atherosclerosis, infections (inflammation of the vessel) or head trauma. Aneurysms are mostly located at the base of the brain and cause bleeding in the cerebrospinal fluid there. The annual risk of bleeding from aneurysms is approximately 1%.
Types of Aneurysms
Saccular (pouch-shaped) aneurysms
It is the most common type of aneurysm and occurs in the bifurcation of the great vessels at the base of the brain. At these bifurcation points, the vessel wall is exposed to more pressure. This constant pressure can cause ballooning as a result of damage to the vessel wall over time. Saccular aneurysms develop over the years and therefore the risk of rupture of the aneurysm increases with age. We can liken this development of aneurysm to the ballooning seen in tire inner tubes used in vehicles in the past. Loss of flexibility of the vessel wall as a result of deterioration of the vascular structure in advanced ages is another important reason for the formation of aneurysms.
Fusiform (spindle-shaped) aneurysms
This aneurysm appears as a spindle-shaped enlargement involving a long section of the vessel. This type of aneurysm may also rupture and bleed, and may cause stroke-like complaints when it expands and causes pressure on the surrounding brain tissue, or when clots develop and can be separated from it, causing obstruction (embolism) in normal brain vessels.
Mycotic (developing as a result of inflammation) aneurysms
It is rare and develops as a result of microbial disease of the vessel. They are usually sac shaped. Inflammation causes damage to the vessel wall, thus increasing the risk of aneurysm formation and rupture as a result of weakening of the wall. It is often a complication of subacute bacterial endocarditis (known as ‘cardiac rheumatism’ in our society).
Traumatic (accidental) aneurysms
It is a type of aneurysm that develops after an accident in the blood vessels of the brain. The damaged vessel wall at the trauma site weakens and may subsequently rupture.
Prevalence and Frequency in the Community
The frequency of cerebral hemorrhage due to brain aneurysm is around 10-15 per 100,000 people in a year. It can be accepted that an average of 10,000 people per year in our country are at risk of cerebral hemorrhage due to aneurysm. About 1/3 of these patients die before they can apply to any health institution. The mortality rate in patients with bleeding who can apply to a health institution is between 25-40%. Therefore, almost half of the patients whose aneurysm bleed die. An important point here is the early diagnosis and treatment of brain aneurysms that have not yet bled but still put the patient at risk. Aneurysm can be seen in all age groups, but the frequency increases gradually in the age of 25 and above. Its prevalence is most common between the ages of 50-60 and it is seen 3 times more in women than in men. Having a family history of aneurysm increases the risk of having aneurysm in other family members. Having more than one aneurysm at the same time increases this risk even more.
Although the exact cause of aneurysm is not known, it is known that many factors play a role in its development.
1) Hypertension (high blood pressure)
2) Smoking/nicotine use
3) Diabetes
4) Excessive alcohol consumption
5) Congenital (genetic) predisposition
6) Damage to blood vessels (especially atherosclerosis) or trauma
7) Certain infections
Symptoms/Warning Signs
Some warning signs may be seen in patients with aneurysm rupture/bleeding.
Headache that persists in any region
Nausea and vomiting,
Stiffness in the neck (person can’t bend his head easily),
Blurred or double vision
Sensitivity to light (photophobia)
Defects of sensation
Most people with non-bleeding aneurysms may have no symptoms.
Some or all of the following symptoms may be seen in a small group of patients:
Ocular nerve paralysis (such as drooping eyelid, inability to move the eye freely)
Unilateral dilated pupil
Double vision, pain behind or above the eye
Headache that persists in one area
Progressive weakness and numbness
Risks and Complications
Aneurysms When ruptured, subarachnoid hemorrhage (SAH) often develops. Blood passing from the vein to the subarachnoid space with high pressure can accumulate here and cause pressure on the brain, bleeding can also occur inside the brain; blood elements can also reach the lower-pressure spinal cord periphery. Bleeding from aneurysm can sometimes be in the form of oozing; In this case, a small clot can form at the leak point and stop the bleeding and the patient can live. However, this process caused by the clot does not prevent the risk of bleeding again; With each additional bleeding, life is more endangered and survival is reduced. Most spontaneous SAHs are caused by aneurysms. Precise determination of the location, size and configuration of the aneurysm is a critical point in its treatment and therefore prevention of rebleeding. The probability of re-bleeding after a bleeding is around 20% for the first 14 days. As mentioned above, aneurysm bleeding is fatal at rates of up to 50%. In addition, it causes permanent neurological disorders at a rate of 25% in living patients. In addition to mental functions, deterioration in all bodily functions (for example, partial paralysis) may occur. In more serious cases, bleeding can cause severe damage to brain cells and put the patient in a coma. If the aneurysm is large, it may cause damage by causing pressure on the surrounding brain tissue without bleeding. In addition, clots may develop in large aneurysms and fragments may cause multiple strokes. Blood leaking around the brain can cause narrowing of the vessels (vasospasm). This can cause a decrease in blood flow to the brain tissue and thus a stroke. Vasospasm usually develops 5-8 days after bleeding. It is very difficult to treat and can endanger the patient’s life. The blood leaking from a bleeding aneurysm may cause hydrocephalus (excessive fluid accumulation in the brain) by preventing the circulation of cerebrospinal fluid (CSF). In this case, excess fluid may accumulate in the spaces called ventricles in the brain, causing an increase in intracranial pressure. In order to prevent this increase in fluid, a drain should be placed in these spaces and the accumulated fluid and leaking blood should be taken out. Aneurysm bleeding can also cause brain edema or swelling. This affects the brain functions and causes very serious problems. Swelling and increased pressure of the brain tissue damage the brain tissue. Cerebral edema can cause pressure on blood vessels, slowing blood flow to the brain.
Diagnostic Methods
According to the medical regulations in force in our country, patients with brain aneurysms can only be admitted to hospitals under the control of neurosurgeons (neurosurgeons). The diagnosis of a bleeding brain aneurysm can be accurately determined by examination, but additional tests are needed to confirm the diagnosis. In this regard, the history of the disease should be well explained to the physician (all related diseases in the past should be reported). Since there is a possibility of additional aneurysms in such a patient, it is vital to use accurate diagnostic tests. The physician needs the right information for the right test to reach the diagnosis.
Brain Angiography: This test is the most valid method for detecting aneurysms. To perform the test, it is necessary to know the patient’s blood picture; This test cannot be performed in a patient with a tendency to bleed. Angiography is generally applied by the radiology department, but with the new regulation, neurology and neurosurgery departments have also started to do this practice. Although a slight sedation with medication is sometimes needed during the procedure, it can usually be done while the patient is awake. While the patient is lying on the examination table, the person who will take the angiography enters the artery with a thin needle from the groin. A small plastic tube (catheter) is then inserted into the vein. The passage of the catheter is visualized under X-rays and it is advanced to the head and neck region where the four main cerebral vessels are located. There is no pain during this procedure. Intravenous dye that can be visualized is given to each cerebral artery separately, and X-ray images are taken during this time. This application allows the vessels to be seen clearly. After the angiography images are taken, the catheter is removed and a pressure dressing is applied to the removed area to prevent blood leakage. After a period of observation, the patient is sent to bed. The patient does not feel the passage of the catheter during the procedure, but a faint sensation may occur on one side of the head during the administration of the dye used, or it may cause temporary star-flying or neck cramps. Although the angiography procedure is sensitive and specific in detecting brain aneurysms that can put the person’s life at risk, it is an invasive procedure for the patient, and there is a risk of damage to the vessel wall, stroke and allergic reaction to the dye used, albeit at low rates.
Computed Tomography-Angiography (CTA): It is a newer technology, and images similar to conventional angiography are obtained by administering the dye from a vein in the patient’s arm. The risk of the procedure is the allergy caused by the dyestuff described in conventional angiography and the potential damage to the kidneys. An important advantage of this method is that there is no need to transfer the patient to the angiography unit and there is no need for additional personnel. In just less than a minute, the shooting process is completed and there is no risk of stroke.
Magnetic Resonance Imaging (MRI): It is a diagnostic test that provides three-dimensional images of the organs of the body by using magnetic field and computer technology. Provides clear images of brain anatomy. Brain MRI can also show signs of pre-existing minor strokes. It is a test that is not harmful to the patient, but since the device is narrow, some people may experience fear of being indoors (claustrophobia). In addition, people who are inconvenient to enter the magnetic field (such as those with a coronary stent or magnetic prosthesis in their body) may encounter problems.
Magnetic Resonance Angiography (MRA): It is a test that can be performed with an MR imaging device and is not harmful to the patient. Magnetic images are analyzed by a computer and the vessels of the head and neck region are displayed. MRA shows true blood vessels and can provide clear information about clogged, narrow vessels and aneurysms.
Treatment Options
Today, there are three important treatment options for patients diagnosed with aneurysm.
Observation and/or non-surgical treatment (monitoring only)
Surgical treatment and aneurysm closure (clip)
Stenting and/or occlusion with intravenous (endovascular) therapy
As in all diseases, the treatment of an aneurysm should be decided by the patient and physician together. If the situation is urgent or if the patient is unconscious as a result of bleeding from the aneurysm, this decision should be made with the patient’s closest relative(s). The treating physician should discuss the risks and benefits of each option with the patient (or relatives). According to the patient’s condition, the most appropriate of these options should be recommended to the patient by the physician. In complex and inappropriate aneurysms, both surgery and intravenous therapy may be required. Neurosurgeons and intravenous therapists can discuss and determine the best treatment option for the patient or their relatives. Today, the best method in the treatment of aneurysm is still a controversial issue, but it should not be forgotten that the treatment should be performed as soon as possible. Surgical risks are also related to whether the aneurysm has bled or not. The size of the aneurysm, its location, and the age and general condition of the patient are other important factors in the success of the treatment.
Observation and/or Non-Surgical Treatment
If the aneurysm is small and has less risk of growth and bleeding due to its location, only follow-up may be a good option. Diagnostic tests should be repeated in the follow-up of these patients. In these people, the risk of annual bleeding continues, albeit small. Additional drug therapy can be given to patients with non-bleeding aneurysms. Follow-up patients should stop smoking and keep their blood pressure under control. These factors are important in aneurysm formation, growth and/or bleeding. If high blood pressure is an important complaint, antihypertensive therapy and/or diet and exercise program may reduce blood pressure. Radiological examination (cerebral angiography, MRA, or CTA) at regular intervals shows changes in aneurysm size and enlargement. Follow-up should be planned in patients with non-bleeding aneurysm after the following factors are thoroughly examined and questioned.
Size and location
Age and health status of the patient
Family history
Treatment risks
Surgical Treatment and Clipping (Latch Closure )
Open surgical treatment is an intervention that has been applied to patients with aneurysms for a long time and is still the gold standard. This surgery is performed to close the aneurysm and is performed under general anesthesia by opening a small window in the skull. The bone is placed back in place at the end of the surgery. The aneurysm is stripped from the surrounding brain tissue and vessels, and the neck is closed with a small metal clip (a kind of small metal clip), usually made of titanium. Normal blood flow is maintained in the vessel where the aneurysm originated. During the surgery, it can be controlled by various techniques that the latch completely closes the neck of the aneurysm and that the flow in other blood vessels continues normally. The clips are permanent, left in place and do not cause any harm to the body. MRI can be performed for people who have undergone this surgery. Under normal conditions, after aneurysm surgery, the patient stays in the hospital for 3 to 5 days, and then home rest for 3-4 weeks is appropriate. The hospital stay for bleeding aneurysms is 7 or more days. After surgical closure of the aneurysm, follow-up angiography may be required 5 years after surgery.
Surgical Treatment and Advantages and Disadvantages of Clipping Advantages of clipping; treatment is often permanent, it does not require reoperation for the same aneurysm, the aneurysm is seen directly (this is important for aneurysms with complex structure), the aneurysm can be deflated after clip application and the pressure of the aneurysm on the brain tissue can be surgically removed and if there is another aneurysm(s) during surgery, it can be seen and treated directly . In those who have bleeding, blood elements and clots in the brain tissue and around the aneurysm can be cleaned during surgery; this cleaning is important in the rapid recovery of some patients. In addition, part of the skull can be removed by craniectomy (removal of some bone from the skull) during surgery and increase in intracranial pressure (such as cerebral edema) that can lead to worsening of patients can be prevented. Disadvantages of surgery; It is an invasive (intrusive) intervention, the skull needs to be opened and related complications may develop. During clip application, surrounding structures and important vessels may be damaged.
Intravenous Therapy -Occupation
Intravenous therapy is a method developed in the last 15 years; It is similar to the process of cardiologists to open blocked vessels in the heart or the great vessels of the body. Especially in the last 5 years, it has come to the fore as an acceptable alternative to surgical clip application. Intravascular treatment may be a suitable option in patients with high surgical risk and poor neurological status, or in some difficult-to-lose aneurysms such as the basilar artery (the great cerebral artery supplying the brain stem and deep brain regions). In a recent study, it was found that in bleeding aneurysms that are suitable for both clip application and intravenous treatment, better results are obtained if intravascular occlusion is applied, at least in the early period (the rate of death or sequelae is 23.5% in patients with occlusion in 1 year, % in surgical clipping. found to be 30). The intravenous occlusion method can be performed under general anesthesia or sedation. The arterial system is accessed through a large vein in the groin (femoral artery in the thigh). A needle is inserted into the artery. Proceeding with a small catheter, four main vessels feeding the brain are reached under the guidance of x-rays. The aneurysm is reached with a smaller catheter (microcatheter) through it. A thin wire or coil is placed inside the aneurysm by positioning the catheter within the aneurysm. Made of bendable platinum, this coil takes the shape of the aneurysm it is in. Additional coils are sent to fill the inside of the aneurysm and the passage of blood flow into the aneurysm is prevented. A clot forms inside the aneurysm, and in the long term, the newly developed tissues fill the base of the coils at the base of the aneurysm and a full recovery is expected. Coil placement with the help of a balloon is another method; here, during the procedure, a balloon is inflated in the neck of the aneurysm with the help of another catheter, preventing the coils from escaping into the vein and keeping them in the aneurysm. Similarly, a small flexible cylindrical cage is used during coil placement with the help of a stent, and this serves as a scaffold for coiling. Both the stent or balloon method described above can be used as treatment options for large-based complex aneurysms.
Advantages and Disadvantages of Intravenous Therapy-Coiling Advantages of intravenous therapy; First of all, it is minimally invasive (with few intervention-related side effects), does not require opening the skull, and has fewer early postoperative complications. Patients with non-bleeding aneurysms can be sent home within a day or two and can return to work within a week or two. Disadvantages of coiling; The aneurysm is less likely to close in the early period and recurrence is more likely. Therefore, an additional intervention may be required and longer follow-up may be required for full treatment.
Recovery and Follow-up
Although recovery varies from patient to patient, aneurysm type, location, whether there is bleeding, type of treatment and general condition of the patient are among the important factors. Neurological losses are more and more pronounced in those who have had a cerebral hemorrhage, and these patients require a longer recovery period. Although each patient has unique findings, some of the side effects that can be seen after surgery are listed below.
Headaches
Drowsiness and fatigue
Pain at the operation site
Jaw pain
Clock ticking sound in the head
Visual disturbances
Partial or complete blindness
Visual field loss
Fine motor movement disorders
Emotional problems
Depression
Conceptual difficulties
Speech problems
Perceptual problems
Behavioral changes
Balance and coordination disorders
Concentration difficulties
Short-term memory problems
As in stroke patients, the recovery and rehabilitation period has an important place in the treatment of aneurysms. In some cases, functions that are lost when the aneurysm bleeds or are treated can be taken over by undamaged brain areas. In rehabilitation, applications can be made in areas such as physical therapy, speech therapy and vocational training.
Screening Tests
It has not yet been proven whether screening for other family members is necessary when an aneurysm is detected in one person. However, if aneurysm is detected in more than one sibling or when multiple aneurysms are detected in one member of the family, screening may be recommended to other members of the family.
