The Source for Neurovascular News and Education

June 13, 2024



The study corroborates prior findings showing flow diversion to be more efficacious than clipping or coiling, researchers say.


Flow-diverting stents are safe and effective for treating paraclinoid aneurysms, and they are the most effective treatment modality for patients presenting with visual symptoms of the aneurysms, according to the results of a new study.

“This study is a single center study that is not randomized, but may reflect the outcomes based on current practice patterns,” Alfred P. See, MD (Brigham and Women’s Hospital, Boston, MA), told Neurovascular Exchange. “This study corroborates prior findings that flow diverters may have better success in improving visual symptoms when compared to clipping and coiling.”

According to See, paraclinoid aneurysms are challenging because there are numerous treatment options available, including open microsurgical reconstruction, endovascular endosaccular occlusion, and endovascular endoluminal reconstruction.

“This leads to diverse treatment paradigms and can make it difficult to accumulate experience to guide the application for each of these techniques, which each have specific advantages and disadvantages,” he said.

In a previous meta-analysis, See and colleagues compared vision outcomes following clipping, coiling, or flow diversion of paraclinoid aneurysms in patients who presented with visual impairment. They found a clear change in clinical practice over time, with a greater representation of clipping than coiling and flow diversion.


More Vision Improvements With Flow Diversion

For their new study, published June 22, 2018, in the Journal of Neurosurgery, See and colleagues conducted a single-center, retrospective analysis of 115 patients with aneurysms of the cavernous to ophthalmic segments of the internal carotid artery. Treatment included flow diversion using the Pipeline Embolization Device (PED; Medtronic; n = 70), coiling (n = 23), or clipping (n = 23). All patients were treated by one interventionist, and postoperative outcomes were compared between the three groups.

The average aneurysm size was 8.2 mm, the average follow-up period was 18.4 months, and 14% were ruptured. Although most of the aneurysms were discovered incidentally, visual impairment was the most common presenting symptom and was present in 18% of patients.

Among those with visual impairment, 71% had improvement after treatment. Of those, 93% were treated with the PED. No patients treated with coiling had improvement. New visual symptoms occurred in 6% of patients, including three treated with PED, but there was no significant difference in occurrence of new symptoms between the three treatment groups.

Most patients had complete angiographic occlusion (89%). Procedural complications occurred in 16% of patients with PED, 9% with coiling, and 17% with clipping. There were significantly more procedural complications in patients with incomplete aneurysm occlusion (P = 0.02).

The flow-diverting PED stent has Food and Drug Administration approval in the United States for treatment of giant paraclinoid aneurysms, but its use has broadened to include smaller paraclinoid aneurysms as neurointerventionists have gained experience, allowing for improved predictability of outcomes and refined techniques to reduce risks and complications.




Silva MA, See AP, Khandelwal P, et al. Comparison of flow diversion with clipping and coiling for the treatment of paraclinoid aneurysms in 115 patients. J Neurosurg. 2018;Epub ahead of print.



See reports no relevant conflicts of interest.