Intrasaccular Aneurysm Treatment

What Is Intrasaccular Treatment?

An intrasaccular device is placed entirely inside the aneurysm, the sac that bulges out from the artery. Once released, it expands to fit the aneurysm, and its dense mesh sits across the aneurysm's opening, or neck. The mesh disrupts blood flow into the aneurysm so that it clots off, and over time tissue grows across the neck to seal it.

This is a different approach from the other minimally invasive options. Coiling fills the aneurysm with many soft platinum coils. A flow diverter is placed in the parent artery. An intrasaccular device does its work from inside the aneurysm, and usually nothing is left in the main artery.

Why It Matters

Aneurysms that form where an artery divides into branches, called bifurcation aneurysms, are among the hardest to treat. When their necks are wide, coils tend to spill back into the artery, so coiling often requires a stent to hold them in place. A stent in the artery means months of blood-thinning medication. An intrasaccular device can often treat these aneurysms without a stent, so many patients avoid long-term dual antiplatelet therapy. Most patients still take aspirin or another antiplatelet medication around the procedure and for a period afterward.

In the United States, the WEB device is FDA-approved for certain wide-necked bifurcation aneurysms, and it has become an important option alongside coiling, clipping, and flow diversion.

Technique, Not Just a Device

The WEB is the most established intrasaccular device in the United States, and newer designs are being studied. Whatever the device, results depend on technique: measuring the aneurysm precisely on three-dimensional imaging, choosing the right size and shape, and confirming the device sits correctly across the neck before it is released. Small differences in sizing make a real difference in how well an aneurysm seals.

I am a certified proctor for the WEB device, which means I work with the device's manufacturer to train other physicians in its use. I have also published a review of intrasaccular flow disruption in JAMA Neurology, which you can find on my research page.

Who Is a Candidate?

Intrasaccular devices work best for wide-necked aneurysms at branch points, including those at the middle cerebral artery bifurcation, the tip of the basilar artery, the anterior communicating artery, and the end of the internal carotid artery. The aneurysm's size and shape matter: some aneurysms are too small, too large, or too irregular for current devices. Your imaging determines whether intrasaccular treatment is a good fit, or whether coiling, flow diversion, or clipping would be better.

What to Expect

The procedure is performed under general anesthesia. Through a small puncture in an artery in the wrist or groin, I guide a microcatheter into the aneurysm and deploy the device. There is no incision in the scalp or skull. Most patients spend one night in the hospital and return to normal activities within about a week. Follow-up imaging checks how well the aneurysm has sealed.

Results and Follow-Up

Most aneurysms treated with an intrasaccular device are adequately sealed on follow-up imaging, though a small remnant at the neck is common and is often simply monitored. Some aneurysms partially reopen over time, often because the device compresses, and may need additional treatment. Regular follow-up imaging allows any change to be caught early.

Risks

Every procedure carries risks, including stroke, bleeding, and small risks at the puncture site. Rarely, the aneurysm ruptures during treatment, or a stent or coils are needed during the procedure. Serious complications, including permanent disability or death, are uncommon but possible. I review your individual risks in detail before we decide on treatment.

Why Choose Dr. Walcott for Intrasaccular Treatment?

• Certified WEB Proctor: Trains other physicians in intrasaccular aneurysm treatment
• Published Expertise: Author of a JAMA Neurology review of intrasaccular flow disruption
• The Full Range of Options: Coiling, flow diversion, intrasaccular devices, and microsurgical clipping, so your treatment fits your aneurysm
• Experience: Over 750 brain aneurysms treated
• Harvard and MGH Residency: Neurosurgical training at Massachusetts General Hospital and Harvard Medical School