Brain aneurysm treatment depends on whether the aneurysm has ruptured or not. A ruptured aneurysm is a medical emergency requiring immediate intervention, while an unruptured aneurysm may be treated with surgery, a catheter-based procedure, or careful monitoring over time. The choice between these options hinges on the aneurysm’s size, location, shape, and your overall health.
When Treatment Is Needed vs. Monitoring
Not every brain aneurysm requires surgery. Many small, unruptured aneurysms are discovered incidentally during brain scans for other reasons, and a significant number of these can be safely monitored with periodic imaging rather than treated right away.
Doctors use a scoring system called the PHASES score to estimate rupture risk and guide treatment decisions. It weighs six factors: your ethnic background (Japanese and Finnish populations carry higher risk), whether you have high blood pressure, your age, the aneurysm’s size, whether you’ve had a previous brain bleed from a different aneurysm, and where in the brain the aneurysm sits. Aneurysms smaller than 7 millimeters score lower, while those 20 millimeters or larger add substantially to the risk calculation. Patients scoring below 3 are generally observed, those above 4 are more likely to be offered treatment, and scores of 3 or 4 fall into a gray zone where the decision depends on individual circumstances.
If your aneurysm is being monitored, controlling blood pressure is essential. The American Heart Association recommends that patients with unruptured aneurysms actively treat hypertension, since elevated blood pressure may contribute to aneurysm growth and rupture. Quitting smoking is equally important: smoking increases the risk of both forming new aneurysms and rupturing existing ones.
Surgical Clipping
Surgical clipping is the older and more established approach. A neurosurgeon makes a small opening in the skull (a craniotomy), locates the aneurysm under a microscope, and places a tiny titanium clip across the base, or “neck,” of the aneurysm. The clip cuts off blood flow into the bulge while preserving the normal artery underneath. Modern techniques allow for smaller openings than in the past, which means less scarring and potentially faster healing.
Clipping’s major advantage is durability. The long-term recurrence rate for clipped aneurysms is roughly 1 to 3 percent, making it the most permanent fix available. This is why clipping is often preferred for younger patients who would otherwise need decades of follow-up imaging, or for aneurysms with shapes that make catheter-based treatments difficult.
The trade-off is that it’s open brain surgery. Recovery takes longer than catheter-based alternatives, and some patients experience jaw pain for several weeks afterward from the surgical approach. Physical therapy, occupational therapy, and speech therapy can all play a role in recovery, even when deficits seem minor. Persistent jaw pain beyond six weeks may need targeted physical therapy or gentle stretching.
Endovascular Coiling
Endovascular coiling avoids open surgery entirely. A doctor threads a thin catheter through an artery in the groin, guides it up to the brain using real-time imaging, and feeds tiny platinum coils into the aneurysm. These coils pack together into a mesh-like structure that fills the aneurysm sac, causing blood inside it to clot and sealing it off from circulation.
Because there’s no incision in the skull, recovery is generally faster and less painful. The procedure is also the preferred first-line treatment for many ruptured aneurysms, since speed matters in an emergency. However, coiling has a notable weakness: recurrence. The long-term recurrence rate for coiled aneurysms ranges from 15 to 34 percent, meaning a substantial number of patients will need follow-up procedures. About 29.5 percent of coiled aneurysms show some degree of reopening at one year. This is why regular imaging follow-up, typically with MRI, is standard after coiling.
The overall rate of neurological complications from endovascular treatment of unruptured aneurysms is about 5.7 percent. These complications can include small strokes, coil migration, or bleeding at the catheter insertion site, though many of these events resolve without lasting effects.
Flow Diverters
Flow diverters are a newer category of device, used mainly for large or complex aneurysms that don’t respond well to standard coiling. These are fine mesh stents placed inside the parent artery, across the opening of the aneurysm. Rather than filling the aneurysm with coils, the mesh redirects blood flow past it. Over time, the aneurysm clots off on its own and the artery wall heals over the device.
Several FDA-cleared flow diverters exist, including the Pipeline and Surpass devices. They work best for sidewall aneurysms (those that bulge off the side of an artery rather than sitting at a branch point). Their role in treating aneurysms at artery branch points or ruptured aneurysms is still evolving and not yet standard practice. Patients with flow diverters need to take blood-thinning medication for months afterward to prevent clots from forming on the device.
The WEB Device for Wide-Neck Aneurysms
Some aneurysms have a wide opening, or “neck,” that makes coiling difficult because the coils tend to slip out into the parent artery. The Woven EndoBridge (WEB) device was designed specifically for this problem. It’s a small, ball-shaped mesh cage that a doctor deploys inside the aneurysm through a catheter, where it disrupts blood flow and promotes clotting without needing coils or stents.
The WEB device is used for aneurysms at specific branch points in the brain’s arterial system. Five-year data show it produces better long-term sealing than coiling does for wide-neck aneurysms. In one comparison, coiling achieved complete or adequate closure in fewer than half of wide-neck cases at one year, while WEB devices maintained stronger results out to five years. Because no stent is involved, patients typically don’t need long-term blood thinners afterward.
Emergency Treatment for Ruptured Aneurysms
A ruptured aneurysm causes sudden, severe bleeding around the brain, called a subarachnoid hemorrhage. This is a life-threatening emergency. The immediate priority is securing the aneurysm (with either clipping or coiling) to stop further bleeding, followed by intensive care to manage the cascade of complications that follow.
One of the most dangerous complications after a rupture is vasospasm, where arteries in the brain constrict days later, potentially causing a stroke. Patients are given medication to help prevent this, though the optimal dosing is still not fully standardized and doesn’t account for individual differences in body weight or organ function. The critical window for vasospasm is typically the first two weeks after a rupture, during which patients remain in the intensive care unit under close monitoring.
Recovery After Treatment
Recovery varies significantly depending on whether the aneurysm ruptured and which procedure was used. After an uncomplicated endovascular procedure for an unruptured aneurysm, many patients go home within a day or two and return to normal activities within a few weeks. Open clipping requires a longer hospital stay and a more gradual return to daily life, with fatigue being one of the most common lingering issues.
Recovery from a ruptured aneurysm is a different experience entirely. Patients often spend weeks in the hospital, and the road back can involve physical, occupational, and speech therapy. Low back pain is common after prolonged bed rest and can be managed with gentle stretching or a heating pad. Cognitive effects like difficulty concentrating, memory issues, and emotional changes are frequent even when the physical recovery goes well. These deficits can improve over months to years, and rehabilitation therapy helps even when the problems seem subtle.
Long-term follow-up is essential regardless of the treatment method. Coiled aneurysms require periodic imaging to check for recurrence. Clipped aneurysms are more durable but still warrant occasional screening, especially since having one aneurysm increases the chance of developing another elsewhere in the brain.