What is the management of a 3mm inferior basilar artery (BA) aneurysm?

From the Guidelines

For a 3mm inferior basilar artery aneurysm, observation with regular imaging follow-up is typically recommended rather than immediate intervention. This approach is based on the guidelines for the management of patients with unruptured intracranial aneurysms, which suggest that the treatment risk is related to advancing age, medical comorbidities, and aneurysm location and size 1. Given the small size of the aneurysm (3mm), the rupture risk is considered relatively low, and the risks of intervention may outweigh the benefits.

Key Considerations

• The size of the aneurysm is a critical factor in determining the risk of rupture, with smaller aneurysms (< 10mm) having a lower risk of rupture 1.
• The location of the aneurysm, in this case, the inferior basilar artery, is also an important consideration, as aneurysms in this location may have a higher risk of rupture 1.
• The patient's age, medical comorbidities, and other factors should also be taken into account when determining the best course of management 1.

Management Approach

• Observation with regular imaging follow-up is recommended, with periodic imaging surveillance using MRA or CTA at 6-12 month intervals initially, then annually if the aneurysm remains stable.
• Controlling modifiable risk factors, such as maintaining normal blood pressure, quitting smoking, limiting alcohol consumption, and maintaining healthy cholesterol levels, is also important.
• Surgical intervention would only be considered if the aneurysm shows growth (beyond 7mm), changes in morphology, or if the patient develops symptoms specifically related to the aneurysm.

Rationale

• The risks of intervention, including endovascular coiling or surgical clipping, often outweigh the natural rupture risk for aneurysms this small, particularly in challenging locations like the basilar artery 1.
• The conservative approach is preferred, as it allows for monitoring of the aneurysm's size and morphology, while minimizing the risks associated with intervention.

From the Research

Management of Basilar Artery Aneurysms

The management of a 3mm inferior basilar artery (BA) aneurysm can be approached through various methods, including endovascular therapy and microsurgical clipping.

• Endovascular therapy has become a preferred treatment option for basilar tip aneurysms, as it offers a less invasive approach with favorable outcomes 2.
• The choice between endovascular coiling and microsurgical clipping depends on factors such as aneurysm size, location, and patient age 2, 3.
• For small aneurysms like the 3mm inferior BA aneurysm, endovascular coiling may be a suitable option, considering the aneurysm's size and location 2, 4.
• However, microsurgical clipping may still be considered for aneurysms with complex neck morphologies or in young patients desiring a more durable treatment 2, 3.

Treatment Outcomes

• Studies have shown that endovascular treatment can yield good clinical and angiographic outcomes for patients with BA aneurysms 2, 3, 4.
• The outcomes of endovascular coiling and microsurgical clipping have been found to be comparable in terms of neurologic outcome, with good outcomes achieved in the majority of patients 3.
• However, the risk of residual lesions and recurrences may be higher with endovascular coiling, emphasizing the need for close follow-up and potential re-treatment 2, 3.

Considerations for Treatment Planning

• A detailed understanding of the aneurysm morphology and its relation to the surrounding anatomy is crucial for treatment planning 5, 4.
• The use of 3D imaging techniques, such as 3D-DSA, can help characterize the aneurysm and guide treatment decisions 5.
• New devices and techniques, such as flow diverter deployment and intrasaccular flow disruptors, may offer additional treatment options for BA aneurysms 4.