How does an aneurysm form?
In places where the artery divides into branches, the wall experiences the greatest blood pressure. If the muscle layer of the wall at this point is weakened - congenital or due to many years of hypertension and smoking - the area begins to gradually stretch and a pouch is formed. Most often, aneurysms form on the arteries at the base of the brain. Most remain small and never rupture, but as they grow in size and have irregular contours, the risk increases. The rupture leads to subarachnoid hemorrhage, an extremely dangerous condition that requires emergency care.
- Saccular aneurysm is the most common option
- Fusiform - uniform expansion of the vessel
- Giant aneurysm larger than 25 mm
- Mycotic aneurysm in infective endocarditis
- Dissecting aneurysm after trauma
Risk factors
The main controllable factors are smoking and high blood pressure: they both contribute to the formation of an aneurysm and increase the likelihood of rupture. Heredity matters: if two or more close relatives have had an aneurysm or subarachnoid hemorrhage, the risk is significantly higher and a screening examination is discussed. A separate group consists of hereditary connective tissue diseases and polycystic kidney disease. Alcohol and stimulant abuse also increases the risk.
- Smoking is the most significant controllable factor
- Arterial hypertension
- Aneurysms in close relatives
- Polycystic kidney disease, connective tissue syndromes
- Female gender, age over 40 years
- Alcohol and stimulant abuse
- Previous hemorrhage
Symptoms
An unruptured aneurysm is usually silent: it is found by chance. Large formations can put pressure on the cranial nerves and brain tissue, and then double vision, drooping of the eyelid, dilation of the pupil on one side, pain in the eye area, and, less often, visual field impairment or convulsions appear. Sometimes, days or weeks before a rupture, a so-called signal headache occurs - an unusual, sudden and intense pain that goes away on its own. When a rupture occurs, the picture is dramatic: instant severe headache, vomiting, photophobia, neck stiffness, and often loss of consciousness.
- Most often - complete absence of symptoms
- Double vision and drooping of the eyelid with a large aneurysm
- Pupil dilation on one side
- Pain behind the eye and in the temple area
- Seizures
- Signal headache before rupture
- Sudden severe headache upon rupture
Diagnostics
For routine search for aneurysms, MRI of the brain with vascular examination is best suited: it does not require contrast or radiation exposure. If a rupture is suspected, the first step is always a CT scan of the brain, which quickly shows blood under the membranes. To accurately determine the shape, neck and size of the aneurysm before surgery, CT angiography of intracranial arteries or direct cerebral angiography is performed - the most accurate method. The found aneurysm is described by size and location, and these data determine the tactics.
- MRI of the brain and cerebral vessels
- MSCT of intracranial arteries with contrast
- MSCT of the brain for suspected rupture
- Cerebral angiography before surgery
- Examination by a neurologist and ophthalmologist
- Control of blood pressure and lipid spectrum
Treatment and observation
Not every aneurysm needs to be closed. If they are small in size, have the correct shape and have a low risk of rupture, they choose observation with repeated studies at certain intervals, plus mandatory smoking cessation and strict blood pressure control. If the risk of rupture is assessed as significant, two approaches are discussed: endovascular embolization, when the aneurysm is filled with coils through a catheter from a vessel on the thigh, and open clipping, when a clip is applied to the neck of the aneurysm. The choice depends on anatomy, age and concomitant diseases and is made by the neurosurgeon together with the patient.
- Complete smoking cessation
- Targeted blood pressure control
- Planned follow-up with repeated vascular MRI
- Endovascular embolization with coils
- Microsurgical clipping
- Avoiding sudden straining and heavy lifting until the issue is resolved
- Examination of close relatives in family cases