Illustration of bilateral aneurysm coiling technique.

Bilateral Approach for Aneurysm Treatment: A Game-Changer?

Reese Marlowe in Health & Wellness November 2025 • 4 min read.

"Discover how a novel approach to stent-assisted coiling can offer new hope for complex PICA aneurysms."

Aneurysms of the posterior inferior cerebellar artery (PICA) present a significant challenge to neurosurgeons, largely due to their complex anatomy and proximity to critical brain structures. Traditional treatment methods can be risky, leading to a continuous search for more effective and safer approaches.

Recent advances in endovascular techniques and tools have improved outcomes, with a focus on preserving PICA flow during treatment. Stenting into the PICA is often considered the best way to maintain this flow, but it is technically difficult to achieve through the ipsilateral vertebral artery (VA), especially when the PICA arises at an acute angle from the aneurysm sac.

In such cases, a bilateral approach for stent-assisted coiling presents a creative alternative. This method aims to achieve two critical goals: complete aneurysm occlusion and preservation of PICA flow. By using an ipsilateral approach for coil delivery and a contralateral cross-over approach for stent delivery via a retrograde smooth path into the PICA, this technique offers a promising solution for complex PICA origin aneurysms.

Why a Bilateral Approach?

Illustration of bilateral aneurysm coiling technique.

The conventional method for treating PICA aneurysms involves navigating through the vertebral artery on the same side as the aneurysm. However, this can be incredibly challenging when the PICA branches off at a sharp angle. Imagine trying to thread a needle through a tiny, angled opening—the bilateral approach offers a more direct route.

The bilateral approach utilizes both vertebral arteries to access the aneurysm. Here’s how it generally works:

Ipsilateral Access for Coiling: A catheter is inserted into the vertebral artery on the same side as the aneurysm to deliver coils that block blood flow into the aneurysm.
Contralateral Access for Stenting: A separate catheter is guided through the vertebral artery on the opposite side, crossing over to the affected side to deploy a stent. The stent provides support to the weakened artery wall and helps maintain PICA flow.

This technique allows for smoother navigation and more precise placement of the stent, reducing the risk of complications. Think of it as having two hands to complete a delicate task—one to stabilize and the other to perform the intricate work.

The Future of Aneurysm Treatment

The bilateral approach for stent-assisted coiling represents a significant step forward in the treatment of complex PICA aneurysms. While further research and long-term follow-up are essential, this innovative technique offers a promising avenue for achieving both aneurysm occlusion and PICA preservation, ultimately leading to better outcomes for patients facing this challenging condition.

About this Article -

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This article is based on research published under:

DOI-LINK: 10.7461/jcen.2012.14.3.223, Alternate LINK

Title: Bilateral Approach For Stent-Assisted Coiling Of Posterior Inferior Cerebellar Artery Aneurysms - Two Cases

Subject: Industrial and Manufacturing Engineering

Journal: Journal of Cerebrovascular and Endovascular Neurosurgery

Publisher: Korean Society of Cerebrovascular Surgeons/Korean Society of Endovascular Surgery

Authors: Se-Il Jeon, Bae Ju Kwon, Dae-Hee Seo, Hee In Kang, Sung-Choon Park, Il-Seung Choe

Published: 2012-01-01

Everything You Need To Know

What makes Posterior Inferior Cerebellar Artery (PICA) aneurysms so difficult to treat?

PICA aneurysms present a significant challenge due to their complex anatomical location and their proximity to critical brain structures. This complexity makes traditional treatment methods risky, leading to a continuous search for more effective and safer approaches. The acute angle at which the PICA branches off from the aneurysm sac can further complicate procedures, especially when attempting to thread devices through the ipsilateral vertebral artery (VA).

What is the bilateral approach for stent-assisted coiling, and how does it improve PICA aneurysm treatment?

The bilateral approach for stent-assisted coiling is an innovative technique used to treat complex PICA aneurysms. It involves using both vertebral arteries to access the aneurysm. Specifically, the ipsilateral vertebral artery is used for coil delivery to block blood flow into the aneurysm, while the contralateral vertebral artery is used for stent delivery, providing support to the weakened artery wall and maintaining PICA flow. This method allows for smoother navigation and more precise stent placement, reducing the risk of complications. By achieving complete aneurysm occlusion and preserving PICA flow, it offers better outcomes for patients.

Why is preserving Posterior Inferior Cerebellar Artery (PICA) flow so important during aneurysm treatment?

Preserving PICA flow during aneurysm treatment is crucial because the PICA supplies blood to critical areas of the brain, including parts of the cerebellum and brainstem. Maintaining adequate blood flow to these regions is essential for various functions, such as coordination, balance, and vital autonomic functions. If the PICA flow is compromised during treatment, it can lead to significant neurological deficits. Stenting into the PICA is often considered the best way to maintain this flow.

In the bilateral approach, what role does each vertebral artery (VA) play in treating PICA aneurysms?

In the bilateral approach, each vertebral artery (VA) plays a distinct role. The ipsilateral VA, which is on the same side as the aneurysm, is used for coil delivery. A catheter is inserted into this artery to deliver coils that block blood flow into the aneurysm. On the other hand, the contralateral VA, on the opposite side of the aneurysm, is used for stent delivery. A separate catheter is guided through this artery, crossing over to the affected side to deploy a stent, which provides support to the weakened artery wall and helps maintain PICA flow.

What are the potential implications of using the bilateral approach for stent-assisted coiling in the long term?

The bilateral approach for stent-assisted coiling holds significant promise for improving outcomes in complex PICA aneurysms by achieving both aneurysm occlusion and PICA preservation. However, the long-term implications, including the durability of the stent and coils, as well as the potential for delayed complications such as in-stent stenosis or aneurysm recurrence, need further evaluation. Continued research and long-term follow-up studies are crucial to fully understand the benefits and risks associated with this innovative technique. Understanding these aspects will determine its role in the broader landscape of aneurysm treatment.