An intracranial aneurysm is the equivalent of an untimely bomb in the skull. It is untimely because there is no telling when it will break, but once it ruptures, the death or disability rate is extremely high. There is no way to prevent the occurrence of intracranial aneurysms, and most patients are diagnosed with intracranial aneurysms only when they have brain hemorrhage. In recent years, many health screening units have included magnetic resonance imaging (MRA) as a routine screening treatment item, increasing the diagnosis rate of unruptured aneurysms. So, how should ruptured or unruptured aneurysms be treated and how should treatment options be chosen?
What is a cerebral aneurysm?
An intracranial aneurysm is not a tumor, but a localized bulge in the wall of an intracranial blood vessel, just like a bicycle tire that bulges out locally before it bursts, and the wall of this bulge will be very thin. Clinically, aneurysm patients also often have aneurysm rupture when they are emotionally excited, forceful and other blood pressure fluctuations, and some patients bleed when they are calm, often with severe headache as the prominent manifestation, and the patient describes the pain as cracking or exploding. Once an intracranial aneurysm ruptures and bleeds, the death and disability rate is extremely high.
The death rate of the first hemorrhage is as high as 35% and the death rate of the second hemorrhage is 60% to 80%, and the survivors are mostly disabled. Patients with suspected aneurysm of brain hemorrhage should be examined as early as possible and treated for the aneurysm as soon as possible. Of course, aneurysms are also benign diseases, and if diagnosed in time and treated with modern neurointerventional or surgical procedures, patients can be cured for life after surgery.
What are the symptoms of aneurysm patients?
Intracranial aneurysms that do not rupture usually do not cause any clinical symptoms, with a few symptoms such as headache and droopy eyelids, which causes many patients to visit the hospital only after the aneurysm ruptures and bleeds. Once an aneurysm ruptures and bleeds it often presents with a severe headache, along with frequent vomiting, profuse sweating, body temperature may rise, and neck stiffness. There may also be impaired consciousness and coma, and some patients may even die suddenly before they can get medical attention.
What is the incidence of aneurysms?
The prevalence of intracranial aneurysms in the population ranges from 2% to 7% and can develop at any age, with common occurrences between the ages of 40 and 60, but there are significant geographic and racial differences in their incidence. Studies have shown that the prevalence of intracranial aneurysms in Asian populations is 2.5%-3.0%, but the majority of patients remain asymptomatic throughout their lives, and about 0.5%-3.0% will rupture and bleed, which can have serious consequences if they do.
Are aneurysms congenital? Do I need to check my brain for aneurysms during my regular physical examination?
Aneurysms are usually not congenital and most aneurysms do not appear until the age of forty. It is controversial whether to screen for intracranial aneurysms in a healthy population. The Chinese expert consensus is that MRA or CTA is feasible in people with a family history or genetic disorders associated with the development of aneurysms, such as patients with polycystic liver, polycystic kidney or Marfan syndrome, especially in women, age >30 years, smoking or with hypertensive disease, to rule out the presence of intracranial aneurysms, and that digital subtraction angiography (DSA) is mandatory if intracranial aneurysms are found or suspected ) to confirm the diagnosis.
How is an aneurysm diagnosed?
A ruptured cerebral aneurysm causing subarachnoid hemorrhage can cause severe headache, coma and other typical symptoms, which can be confirmed by immediate cerebral angiography.
It is difficult to diagnose cerebral aneurysm without any symptoms before it ruptures because patients usually do not go to the hospital for these special tests without any physical discomfort. For those who have the following symptoms, they should be alert: ptosis of one upper eyelid without other symptoms or triggers; sudden onset of headache on one side with pulsating pain located around the orbit; visual field loss on one side, etc. When any of the above symptoms occur, be sure to go to a hospital in a condition to have a CT or MRI examination and, if necessary, a cerebral angiography (DSA) examination.
What conditions can lead to aneurysm rupture?
Prof. Shih: At present, we are not sure why or when an aneurysm will rupture, but it is generally believed that the following conditions may increase the risk of aneurysm rupture: firstly, high blood pressure, weight bearing or constipation in the toilet will increase the pressure in the brain, which will lead to aneurysm rupture and bleeding. The second is emotional stress, when there is a lot of joy or anger, which can lead to an increase in cerebral blood pressure, which can lead to a ruptured aneurysm. We often encounter patients arguing with others before aneurysm rupture, or even some patients when playing mahjong hokum. The third is oral anticoagulant drugs, such as warfarin.
What kind of aneurysm is prone to rupture?
There are many factors that determine how likely an aneurysm is to rupture, such as the size, shape and location of the aneurysm, as well as the clinical symptoms caused by the aneurysm. International studies have concluded that the risk of bleeding is significantly increased for aneurysms >7mm in diameter. Studies in Asian populations have concluded that the risk of aneurysm rupture is greatly increased for aneurysms >5 mm in diameter. For irregularly shaped aneurysms, the risk of rupture is significantly higher than for regularly shaped aneurysms. Once an aneurysm has ruptured, it is prone to re-rupture; therefore, the sooner it is treated, the better.
Should an unruptured aneurysm be treated aggressively?
The management of unruptured aneurysms is still one of the controversial topics both nationally and internationally. For asymptomatic unruptured aneurysms, the size of the aneurysm mentioned by Prof. Shih is an important deciding factor, and treatment is generally recommended for aneurysms with a diameter of 5mm or more. For aneurysms less than 5mm in diameter, a variety of other factors should be considered, including the location and shape of the aneurysm, to fully assess the risk of aneurysm rupture.
For some patients who know they have an aneurysm and are under more psychological stress, which seriously affects their normal work life, a more aggressive treatment approach can be taken. Aneurysms treated conservatively should be followed up with long-term review.
For unruptured aneurysms with symptoms, all should be treated actively, which has been agreed at home and abroad. Regardless of the size of the aneurysm, any aneurysm that causes associated neurological symptoms and signs should be treated aggressively surgically. Because the appearance of these symptoms may be associated with the rapid increase of aneurysm size or a small amount of blood leakage, which indicates a high possibility of aneurysm rupture and bleeding.
Therefore, symptomatic intracranial aneurysms are an absolute indication for treatment and should be treated as soon as possible to avoid delays that could lead to fatal and extensive bleeding. Studies have shown that 10-43% of patients may develop a warning headache prior to a brain hemorrhage, and that patients who develop this headache are ten times more likely to have a recent rebleed, which occurs mostly 2-8 weeks prior to an apparent brain hemorrhage.
What are the consequences or symptoms of a ruptured aneurysm?
When an aneurysm ruptures, blood can exit the cavity around the brain tissue in what is known clinically as a “subarachnoid hemorrhage”. Depending on the amount of bleeding, the following symptoms may occur: first, a sudden, severe headache that may last for hours or days; second, nausea and vomiting; third, drowsiness or even coma; and fourth, or, in the most severe cases, sudden death.
The bleeding can also directly damage the brain, called “hemorrhagic stroke”, which may result in the following symptoms: first, weakness or hemiparesis of the arms or legs; second, inability to speak or understand speech; third, visual impairment; and fourth, epilepsy.
After a ruptured aneurysm bleeds, in addition to the brain tissue injury caused by the bleeding itself, it can also trigger cerebral vasospasm, which mostly occurs 3-14 days after subarachnoid hemorrhage and may occur in about 15-20% of patients. The blood clot irritates the vessel wall, causing strong vasoconstriction, which in severe cases can lead to ischemic necrosis of brain tissue, and the patient becomes comatose and hemiplegic. Some other secondary problems that may occur include hydrocephalus, cerebral edema, respiratory distress, and infection.
In conclusion, for a ruptured aneurysm, even if the aneurysm itself is no longer bleeding through intervention or open surgery, the blood that has already been removed itself is more difficult to treat. The patient’s prognosis depends on the amount of bleeding that starts and is most visually evident in the severity of the patient’s clinical symptoms after bleeding.
What treatment options are available for aneurysms? How to choose?
Treatment of intracranial aneurysms includes minimally invasive interventional therapy and surgical craniotomy. A large foreign study showed that interventional treatment is significantly less fatal and disabling than craniotomy. Since the publication of the results of this study, more and more physicians in China and abroad tend to use interventional methods to treat aneurysms. Our recommendation is that for unruptured aneurysms, interventional treatment is preferred. For ruptured aneurysms, the treatment should be determined by the site and shape of the aneurysm. Some aneurysms are suitable for interventional treatment and some aneurysms are suitable for surgical open clamping. For aneurysms for which both interventional and surgical treatments are suitable, it is internationally accepted that interventional treatment is preferred, after all, it is less traumatic and risky, and recovery after surgery is faster. Of course, each family has to choose according to their financial ability, because the cost of interventional treatment is slightly higher than that of surgical opening.
Can you briefly introduce the interventional treatment of aneurysm?
Interventional treatment is to fill the aneurysm from inside the artery with a metal spring coil made of a special alloy material so that blood cannot enter the aneurysm and the wall of the aneurysm is not subjected to the pressure of the impact of blood flow, and no further bleeding occurs. Interventional treatment is minimally invasive and involves puncture through the femoral artery, postoperative compression dressing, and wound healing the day after surgery. For unruptured aneurysms, the patient can be discharged two or three days after surgery. For ruptured aneurysms, the length of stay depends on the amount of bleeding, usually one to two weeks.
What are the possible complications of aneurysm treatment?
The complication rate of interventional treatment is very low. The most important one is intraoperative aneurysm re-rupture and bleeding, which is related to the characteristics of the aneurysm itself and the level of the operator. The location and shape of some aneurysms are too large for intervention, which increases the incidence of intraoperative bleeding; the skill level of the operator is also an important factor in the incidence of intraoperative complications, and the rate of intraoperative bleeding may be relatively high for beginners, while there have been no cases of intraoperative aneurysm rupture in our department in recent years. Another possible major complication is that the blood vessels in the brain are affected, and sometimes the spring coil can compress the normal blood vessels in the brain, which can cause cerebral ischemia and lead to clinical symptoms such as speech dysfunction and hemiparesis. Of course, the incidence of these complications is extremely low.
What should I pay attention to after aneurysm treatment?
The most crucial point is to have regular review. Although the rate of recurrence after aneurysm treatment is not very high, the possibility of recurrence or even re-rupture does exist. We suggest patients to review cerebral angiography about six months after aneurysm treatment to understand the condition of the aneurysm, and then decide when to review it again and how to review it based on the results of the review. Another thing is to control blood pressure and avoid abnormal life style.
Besides aneurysm, what other diseases can cause brain hemorrhage? How to diagnose and treat?
There are many diseases that cause cerebral hemorrhage, including hypertensive hemorrhage, dural arteriovenous fistula, cerebrovascular malformation, smoldering disease, cavernous hemangioma, and so on. The most reliable way to diagnose hemorrhage due to vascular disease is to perform a whole brain angiogram. Interventional treatment is now available for dural arteriovenous fistulas and cerebrovascular malformations.