A brain aneurysm is an abnormal, outward bulging of an artery in the brain caused by weakness in the arterial wall. The main 2 categories of aneurysms include fusiform and berry. Aneurysms can occur at any age, however, aneurysms are most often detected in patients between the ages of 40 and 60 years. In addition, aneurysms are more prevalent among women (60%) and approximately 20% of patients have 2 or more aneurysms. Many patients have no symptoms or complaints until the aneurysm ruptures. In some cases however, there are warning signs. Some patients experience limited eye movement, dilated pupils, double vision, pain above and/or behind the eye(s) or headache.
What causes brain aneurysms?
There are various causes for brain aneurysms. Some people may be genetically prone to aneurysms which is why your physician is interested in your family history. An estimated 6 million people in the US have an unruptured brain aneurysm (1 in 50 people). These risk factors may also contribute to the development of a brain aneurysm. Most patients with brain aneurysms have no underlying disorder. On the other hand, many known disorders are associated with increased risk of forming aneurysms: polycystic kidney disease, sickle cell disease, and various connective tissue disorders. Common conditions which encourage aneurysm growth and increase the likelihood of rupture include hypertension and smoking.
How are brain aneurysms treated?
The two main options are endovascular treatment (which is performed through catheters inserted into the arteries under x-ray guidance) and open surgery. Which option is best depends on many factors: aneurysm location, size, patient condition, patient preference, and local expertise. This decision has to be made on an individual basis. Endovascular (catheter-based) treatments continue to evolve so that more and more aneurysms are now amenable to durable treatment.
Endovascular Coil Therapy
Minimally invasive endovascular techniques have revolutionized the treatment of brain aneurysms previously treatable only with open brain surgery. An increasing number of patients with aneurysms can potentially benefit from the coil treatment. This treatment is less invasive and safer than traditional surgical clipping. In addition, it usually requires a shorter hospital stay and has a shorter recovery time. Patients who benefit the most from coiling are those whose aneurysm sacs hang off the blood vessel by a narrow neck. During endovascular treatment, a catheter is inserted into the femoral artery and is advanced through the body to the aneurysm. Small soft platinum coils are inserted through the catheter until the flow of blood into the aneurysm is blocked. This reduces pulsation and over time, new tissue will cover the opening of the aneurysm, preventing the aneurysm from growing or bleeding. This procedure is performed under angiography which allows the Neuro Interventional Radiologist to visualize vessels to assist with properly placing the coils. By blocking the flow, the pressure on the aneurysm is reduced. In some cases, the neck or opening in the aneurysm is very large and it is possible that the coils can prolapse or migrate out of the aneurysm sac. In these cases, a stent may be placed inside the artery and provide a bridge to keep the coils inside the aneurysm. Occasionally, a balloon catheter may assist with inserting the coils into the aneurysm.