The Preoperative Functional Downgrading of Brain AVMs

Area of Science:

• Neurosurgery
• Interventional Neuroradiology
• Vascular Neurology

Background:

• The role of preoperative embolization for brain arteriovenous malformations (AVMs) is often underestimated.
• Endovascular techniques are increasingly utilized to manage complex AVMs.

Purpose of the Study:

• To evaluate the effectiveness, safety, techniques, and outcomes of endovascular-based functional downgrading of brain AVMs.
• To assess the impact of preoperative embolization on surgical management and patient results.

Main Methods:

• Retrospective review of 31 Spetzler-Martin grade III AVMs treated with combined endovascular-surgical approach.
• Utilized low-density Onyx for embolization with an average of 1.6 procedures per patient.
• Embolization-to-surgery interval averaged 3.7 days; outcomes assessed by modified Rankin Scale (mRS) and angiography.

Main Results:

• Average AVM obliteration rate of 29.6% with negligible morbidity.
• Complete AVM exclusion achieved in 83.4% of cases post-surgery.
• 77.5% of patients achieved favorable mRS scores (0-2), with best outcomes in small to medium-deep malformations.

Conclusions:

• Endovascular functional downgrading of brain AVMs is an effective and safe strategy.
• Specific technical aspects, including superselective catheterization and Onyx use, are crucial for optimizing surgical outcomes.
• This approach facilitates easier dissection and leads to successful AVM exclusion and improved patient functional status.