What was the usual treatment of aneurysms in the past?
Until a few years ago the aneurysm was treated surgically. Today, for certain aneurysms, surgery is still valid; however, treatment is moving towards less invasive techniques that make it possible not to open the skull and to access the aneurysm endovascularly.
What is the objective of intervening on aneurysms?
The aim is to fill the aneurysm and isolate it. Endovascular treatment began in the 1990s when a system of very flexible platinum coils was devised that were placed inside the aneurysm. Over time, blood flow compacted the coils and the neck of the aneurysm reopened, resulting in possible rebleeding of the aneurysm.
How has aneurysm intervention evolved?
Gradually, techniques appeared that allowed further filling of the aneurysm. These techniques used an inflated balloon in front of the aneurysm, which could increase the density of coils in the aneurysmal neck. The chances of reopening were lower, but they were still observed.
What solution was sought?
It was thought necessary to change the direction of flow. To change it, the only possible option was endovascular stents, such as those placed in the coronary arteries, which would allow the flow, instead of going towards the aneurysm, to continue through the artery.
What are these stents like?
These new prostheses have a dense mesh that allows a slowing of blood flow to the aneurysm. At the same time, the stents should allow blood to flow to areas where there is a call effect, such as in the arteries that may be around the aneurysm. It is the revolution of the new Stents.
Are there varieties of stents?
There are two types of stents; some are made of dense mesh and others are covered by a multiperforated membrane. Both keep the arteries open but plug the aneurysm.
Disadvantages of Stents
The stent is a foreign body that the body tends to reject and create clots. To prevent this from happening, it is necessary to medicate the patient with antiplatelet agents: two for a few months (clopidogrel and aspirin) and one (aspirin) thereafter. This fact limits the number of people to whom we can perform this intervention, which is contraindicated in patients with gastric ulcer, digestive problems or bleeding.
In what type of aneurysms are stents indicated?
Stents are indicated above all in giant aneurysms or those with a wide neck, which if not treated with this technique frequently revascularize after treatment. In small aneurysms and with a small neck, the traditional technique (platinum coils) can be used, which is still valid. The coils have been shown to be a far superior technique to open surgery. Moreover, the quality of life of patients treated endovascularly has been superior to those treated surgically.
Can the treatment of giant aneurysms be performed in all centers?
Nowadays there is a tendency to resolve aneurysms endovascularly, but there are not enough teams trained to operate on any type of aneurysm. In Spain, most hospitals can resolve standard aneurysms, but to treat highly complex aneurysms, the number of trained teams is lower. It is necessary to master all techniques in the treatment of aneurysms: the traditional, the use of balloons, the Stent or combine several. In addition, it is necessary to have access to an important infrastructure: Intensive Care Unit, Neurology Service, Neurosurgery and Radiology that allows access to high-definition resonance imaging and computed tomography.
Which aneurysms should be treated?
The tendency is to keep under control (although without intervening) aneurysms of less than five millimeters, asymptomatic and with a low probability of bleeding. When they exceed that size there is a greater probability of bleeding. Then it is advisable to indicate a treatment.
Treatment of aneurysms
It is preferable that the treatment be endovascular rather than surgical. The risk of bleeding is cumulative over the years. Although the risk increases by only 2.5% each year, it should be noted that the figure after a decade reaches 25%. Half of the patients do not reach the hospital when their aneurysm starts to bleed. Of those who arrive, only half remain in good condition. The rest are left with a serious deficit or end up needing assistance to continue with a normal development in their lives.
For more information, consult a specialist in Neuroradiology.