What is an aneurysm?
Localized bulging of the blood vessels due to thinning of the wall is known as aneurysm. The most common sites of aneurysms are the brain (cerebral aneurysm) and the aorta (thoracic and abdominal aortic aneurysm). Aortic aneurysms (both thoracic and abdominal aortic) usually do not produce symptoms apart from occasional pain in the back, but cerebral aneurysms can produce wide variety of symptoms. Rupture and large amount of blood loss is the main complication. Depending upon the size, rate of growth watchful monitoring or surgery is recommended.
What are the symptoms?
The site of aneurysm decides the nature of the symptoms. Aortic aneurysms are largely asymptomatic. Cerebral aneurysm symptoms depend on whether the aneurysm is intact or ruptured.
- Intact aneurysms: small intact aneurysms do not produce any symptoms. But due to their growth subsequent pressure on the surrounding brain tissue or neurons can cause symptoms (pressure symptoms) like :
– Pain behind the eye
– Occasional headache
– Visual disturbance (double vision)
– Drooping of eye lids (ptosis)
– Weakness of limbs
– Deviation of mouth
- Ruptured aneurysms: Presenting features are quite different. Initially when the aneurysm just begins to leak blood, sudden excruciating headaches occur. Later with increased complete rupture the following symptoms are noted :
– Severity of headache increases
– Stiffness of neck
– Nausea and vomiting
– Double vision
– Sensitivity to light (photophobia)
– Convulsions (seizures)
– Drowsiness, confusion and finally a complete black out
- Aortic aneurysm: like brain aneurysm small aortic aneurysms do not produce any symptom.Both thoracic and abdominal aneurysms upon enlargement produce common symptoms like pain in the back, chest and abdomen.
What are the causes?
Cerebral aneurysms most commonly occur at the base of the brain. Aorta is the major artery of the body arising from the heart (left ventricle), runs through chest and abdomen and ends into terminal branches (iliac arteries) to the legs. Depending upon the location, an aortic aneurysm can be thoracic, abdominal and rarely thoraco-abdominal. An aneurysm occurs due to weakening (thinning) of the vessel wall especially at the point of branching where the wall is the weakest. The weakening is caused by atherosclerosis (fatty deposits “plaques” on the arterial walls) or an infection like third stage of syphilis.
In case of thoracic aneurysm additional causes are :
- Connective tissue disorder: like Marfan’s disease.
- Disease of heart valve: aortic valve (guiding flow of blood from left ventricle to aorta) consists of three cusps, when there is two cusps (bicuspid) risk of aneurysm increases.
Risk factors include :
- Old age
- High blood pressure
- Family history
- Drug addiction: cocaine
- Polycystic kidney disease
- Cerebral arterio-venous malformation: abnormal connection between artery and vein
How is an aneurysm treated?
Surgery is the most definitive treatment and involves procedures like :
- Surgical clipping
- Endovascular coiling
Drug therapy (symptomatic treatment) includes :
- Painkillers, calcium channel blockers, anti seizure drugs
Monitoring is recommended by regular imaging to see the size.
Drug therapy: blood pressure lowering, statins (cholesterol lowering) and ACE inhibitors.
Surgery to prevent rupture (size>5.5cm) and manage ruptured aneurysms :
- Open chest/ open abdomen
- Open heart: with co-existent heart disease (thoracic aneurysm)