Real-World Angiographic and Clinical Outcomes of WEB, Coiling, and Stent-Assisted Coiling for Patients with Unruptured Saccular Intracranial Aneurysms: A Multicenter Study
This multicenter retrospective study from Colombia evaluates the real-world safety and efficacy of stent-assisted coiling, coiling, and WEB devices for unruptured intracranial aneurysms, finding that while stent-assisted coiling showed higher occlusion rates and ischemic complications in the overall cohort, favorable functional outcomes were consistent across all strategies and initial differences were largely attenuated in contemporary analyses, suggesting the results are descriptive rather than definitive evidence of comparative superiority.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
Inside the delicate network of blood vessels that feeds the human brain, a small, balloon-like bulge can sometimes form on the wall of an artery. This is an aneurysm. While many of these bulges sit quietly without causing trouble, they carry a hidden danger: if they burst, they can cause a devastating type of bleeding in the brain. Because modern brain scans are so sensitive, doctors now find these unruptured aneurysms more often than before, usually by accident while looking for something else. The central question for doctors is not just whether to treat them, but how. The goal is to seal the bulge off from the rest of the bloodstream so it cannot burst, while avoiding damage to the healthy vessels around it.
For decades, the standard way to fix these bulges involved threading a tiny wire through the blood vessels to pack the space with soft metal coils, essentially filling the sac until it clots. As technology advanced, two other approaches emerged to handle more difficult shapes. One method uses a tiny mesh tube, called a stent, to act as a scaffold across the neck of the aneurysm, holding the coils in place. The other uses a special woven device that sits entirely inside the bulge to disrupt the flow of blood, encouraging it to clot without needing a permanent tube in the main artery. Each method has its own strengths and risks, but until now, there has been limited real-world data comparing how well they actually work for patients in everyday clinical practice, particularly in Latin America.
A team of researchers from several major hospitals across Colombia set out to fill this gap. They looked back at the records of nearly 400 patients who had unruptured aneurysms treated between 2014 and 2025. These patients were divided into three groups based on the technique their doctors chose: simple coiling, stent-assisted coiling, or the woven intrasaccular device. The researchers followed these patients for a full year, checking their brain scans to see if the aneurysms were successfully sealed and monitoring them for any complications, such as strokes or bleeding.
The study revealed that all three methods are generally safe and lead to excellent long-term health outcomes for the vast majority of patients. More than 97 percent of the people in the study were able to return to their normal lives without significant disability a year after the procedure. However, when the researchers looked closely at the technical success of sealing the aneurysm, differences began to appear. The stent-assisted method, which involves placing a mesh tube, achieved the highest rate of complete sealing, successfully closing off the aneurysm in about 84 percent of cases. Simple coiling followed closely, sealing the bulge in about 75 percent of cases. The woven device, while innovative, resulted in a complete seal in roughly 68 percent of cases.
These numbers tell a story about the trade-offs doctors face. The method that used the stent was the most effective at creating a tight seal, but it came with a higher risk of a specific type of complication: a blockage in the blood vessel caused by a clot forming on the stent. About 12 percent of patients treated with stents experienced some form of this ischemic event, compared to only about 3 percent in the simple coiling group and 4 percent in the woven device group. The woven device had a lower risk of these clots, likely because it does not leave a permanent structure in the main artery that requires strong blood-thinning medication, but it was less likely to achieve a perfect seal on the first try.
The researchers also examined whether the shape or size of the aneurysm predicted which method would work best, but they found that no single factor could reliably predict the outcome across the board. The choice of treatment was heavily influenced by the specific anatomy of the patient's brain and the experience of the doctor performing the procedure. When the team looked at only the most recent cases treated in 2024 and beyond, the differences in success rates became less pronounced, suggesting that as doctors gain more experience with these newer tools, the gap between the methods may be narrowing.
Ultimately, this study suggests that there is no single "best" tool for every aneurysm. The stent-assisted approach offers the highest chance of a perfect seal but carries a higher risk of clot-related complications. The woven device offers a simpler path with fewer clot risks but may require more careful monitoring to ensure the seal holds. The simple coiling method remains a solid, reliable option for many cases. The decision, the researchers conclude, depends on balancing the specific shape of the aneurysm against the patient's ability to tolerate blood-thinning drugs and the doctor's judgment. The goal remains the same for all three: to protect the patient from a future rupture while ensuring they leave the hospital in the same condition they arrived.
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