What is the next step for a 52-year-old male with a 2-week history of severe headaches, no evidence of brain bleed on CT (Computed Tomography) head, and a 5 mm saccular aneurysm with a wide neck off the communicating segment of the left Internal Carotid Artery (ICA) on CTA (Computed Tomography Angiography)?

Management of Unruptured 5mm Wide-Neck ICA Aneurysm

This patient requires urgent neurosurgical and endovascular consultation for treatment planning, with digital subtraction angiography (DSA) as the next diagnostic step to definitively characterize the aneurysm anatomy and determine optimal treatment approach. 1

Immediate Next Steps

Urgent Specialist Consultation

• Patients with unruptured intracranial aneurysms should be evaluated immediately by physicians with expertise in cerebrovascular disease management, ideally at centers with both neurosurgical and endovascular capabilities. 1
• Transfer to a high-volume center (>35 aneurysm cases per year) should be strongly considered, as these centers demonstrate superior outcomes. 1

Definitive Vascular Imaging with DSA

• DSA with 3-dimensional rotational angiography is indicated for definitive characterization of the aneurysm to determine treatment feasibility and planning. 1
• While CTA has already identified the aneurysm, DSA provides superior spatial resolution (>98% sensitivity and specificity) and is essential for determining whether the wide-necked morphology is amenable to endovascular coiling versus surgical clipping. 1
• The wide-neck characteristic is particularly important because CTA can artificially widen the aneurysmal neck due to partial volume averaging, potentially leading to erroneous conclusions about treatment options. 1
• 3-dimensional rotational angiography identifies aneurysms in 25% of cases where standard 2-dimensional angiography was negative, highlighting its superior anatomical detail. 1

Treatment Decision Framework

Size and Rupture Risk Considerations

• At 5mm, this aneurysm falls into an intermediate risk category where treatment is generally favored over observation. 2
• Aneurysms <5mm have very low rupture rates, while those >10mm have significant rupture risk; 5mm represents a threshold where intervention is typically recommended, especially in symptomatic patients. 2
• The patient's symptomatic presentation (two weeks of severe headaches) elevates concern and supports intervention over conservative management. 1

Wide-Neck Morphology Impact

• Wide-neck aneurysms (neck width ≥4mm or dome-to-neck ratio <2) present technical challenges for standard endovascular coiling. 3
• Adjunctive techniques such as balloon-assisted coiling or stent-assisted coiling may be required for successful endovascular treatment of wide-necked aneurysms. 3
• Surgical clipping remains highly effective for wide-necked aneurysms when endovascular options are limited. 1

Blood Pressure Management

Pre-Treatment Blood Pressure Control

• Between aneurysm diagnosis and definitive treatment, blood pressure should be controlled with titratable agents to balance stroke risk, potential rupture from hypertension, and maintenance of adequate cerebral perfusion. 1
• Avoid excessive blood pressure reduction that could compromise cerebral perfusion, but prevent hypertensive surges that increase rupture risk. 1

Treatment Timing

Early Intervention Rationale

• Definitive treatment (surgical clipping or endovascular coiling) should be performed as early as feasible to eliminate rupture risk. 1
• Complete obliteration of the aneurysm is the goal whenever technically possible. 1
• For aneurysms amenable to both approaches, endovascular coiling should be considered first, though wide-neck morphology may favor surgical clipping. 1

Critical Caveats

Avoid These Pitfalls

• Do not delay specialist consultation or definitive imaging—unruptured aneurysms can rupture at any time, with catastrophic consequences (>40% mortality within 30 days). 1
• Do not rely solely on CTA for treatment planning in wide-necked aneurysms, as partial volume averaging can misrepresent neck anatomy. 1
• Do not assume the headaches are unrelated to the aneurysm—symptomatic unruptured aneurysms warrant more aggressive management than truly incidental findings. 1
• Ensure the patient is managed at a center with regular experience treating aneurysms using both endovascular and surgical techniques, as outcomes are operator and volume-dependent. 1