Is the patient with a 6 mm x 4 mm left vertebral V2 segment aneurysm a candidate for coiling?

Management of Left Vertebral V2 Aneurysm: Coiling Candidacy Assessment

The patient with a 6 mm x 4 mm left vertebral V2 segment aneurysm is a suitable candidate for endovascular coiling, which should be considered as the first-line treatment option given its posterior circulation location and moderate size.

Factors Supporting Coiling for this Patient

Aneurysm Characteristics

• Location: Posterior circulation aneurysms, including vertebral artery aneurysms, have better outcomes with endovascular treatment compared to surgical approaches 1
• Size: At 6 mm x 4 mm, this aneurysm falls into the small-to-moderate size category, which has:
  • Lower recurrence rates after coiling compared to larger aneurysms 1
  • Lower risk of hemorrhage after treatment compared to larger aneurysms 1
  • Better complete occlusion rates with endovascular techniques 1

Evidence-Based Treatment Selection

• The American Heart Association/American Stroke Association guidelines specifically recommend endovascular coiling for posterior circulation aneurysms 1
• Subgroup analysis from randomized controlled trials shows a significant benefit of coiling over clipping for posterior circulation aneurysms with a relative risk of 0.41 (95% CI, 0.19-0.92) for death or dependency 1
• The prospective BRAT study demonstrated significantly better outcomes for posterior circulation aneurysms in the coil group compared to the clip group at both 1-year and longer-term follow-up 1

Technical Considerations

Procedural Planning

1. Pre-procedure evaluation:

   • Assess neck-to-dome ratio (important for coil stability)
   • Evaluate relationship to parent vessel
   • Determine need for adjunctive techniques (balloon or stent assistance)

2. Treatment goals:

   • Complete aneurysm obliteration should be the primary goal 1
   • For vertebral artery aneurysms, flow diversion may be considered as an alternative to standard coiling 2

3. Potential challenges:

   • If the aneurysm has a wide neck (>4 mm), incomplete coiling may occur in up to 59% of cases 1
   • Small aneurysms with small necks (<4 mm) have better complete occlusion rates (only 25.5% incomplete coiling) 1

Post-Treatment Management

Follow-up Protocol

• Immediate post-procedure angiography to assess occlusion status 1
• Regular angiographic follow-up is essential, particularly for posterior circulation aneurysms which have higher recurrence rates 2
• Initial follow-up imaging at 6-12 months, then periodically thereafter 2
• Consider retreatment if there is significant aneurysm remnant or recurrence 1

Blood Pressure Management

• Target systolic blood pressure <140 mmHg to reduce risk of complications 2
• Consider more aggressive targets (<120 mmHg) if other risk factors are present 2

Important Caveats

1. Risk of incomplete occlusion: Even with optimal technique, complete occlusion may not be achieved in the first treatment session, particularly if the aneurysm has a wide neck 1

2. Need for multidisciplinary decision-making: Treatment decisions should involve both experienced cerebrovascular surgeons and endovascular specialists 1

3. Potential need for retreatment: If incomplete occlusion occurs, retreatment may be necessary to prevent growth or rupture 1

4. Facility considerations: Treatment at high-volume centers (>35 aSAH cases per year) with experienced cerebrovascular specialists is associated with better outcomes 1

By following these evidence-based recommendations, the patient with a 6 mm x 4 mm left vertebral V2 aneurysm can receive optimal care with endovascular coiling as the preferred treatment modality.