Patients with a ruptured brain aneurysm have a high risk of rebleeding in the first days, weeks, and months after the initial bleeding; this risk is approximately 30-50%. Therefore, an aneurysm that has bled must be treated as an emergency.

Aneurysm treatment can also be performed prophylactically for incidentally found aneurysms, which have not bled. In this case, the risk of surgery or intervention must be carefully weighed against the risk of bleeding if the aneurysm is left untreated. The size and location of the aneurysm, certain risk factors, and the patient's personal preference play a role in the decision process.

The main goal of aneurysm treatment is to prevent inflow of blood into the aneurysm. Two different methods for aneurysm treatment exist (clipping and coiling). During clipping, access to the ruptured aneurysm is gained after removing a section of the skull. The neurosurgeon then places a small metallic clip at the neck of the aneurysm to cut off any blood inflow and prevent a (re)bleeding. Coiling, on the other hand, is a minimally invasive technique where access to the aneurysm is gained with a small catheter inserted at the level of the groin (or wrist). The catheter is carefully navigated from the access site to the affected cerebral vessel harboring the aneurysm. Coils are then advanced through the catheter until the aneurysm is filled. The decreased inflow of blood favors clot formation between the coils. When an aneurysm is filled with coils, it can be considered protected and thus cannot burst. Coils are made of platinum and curl to a predetermined diameter that is adjusted to the size of the aneurysm.

In case of treatment of an incidental aneurysm, antiplatelet drugs (aspirin, clopidogrel) may be prescribed, depending on the type of procedure (e.g. additional use of a stent). Antiplatelets are prescribed to prevent the formation of blood clots during the procedure. If necessary, premedication will be prescribed accordingly by the physician.

For further observation after the intervention, patients are transferred to a monitoring ward. Usually, 6 months after treatment, patients are followed up with magnetic resonance imaging (MRI) and catheter angiography. These examinations are necessary because treated aneurysms can sometimes fill with blood again and grow. A further follow-up is usually done 2 years after the treatment with an MRI. The use of antiplatelet drugs varies according to the type of procedure performed and will be prescribed accordingly by your physician at discharge.