Hemodynamic changes in arteriovenous malformations after radiosurgery: transcranial Doppler evaluation

Area of Science:

• Neurosurgery
• Vascular Neurology
• Medical Imaging

Background:

• Arteriovenous malformations (AVMs) pose risks due to abnormal blood flow.
• Gamma Knife surgery (GKS) is a treatment option for AVMs.
• Monitoring hemodynamic changes post-GKS is crucial for assessing treatment efficacy.

Observation:

• Patients with AVMs exhibited higher mean blood flow velocity (Vm) and lower pulsatility index (PI) in ipsilateral middle cerebral arteries (MCAs) compared to contralateral MCAs.
• Vm in ipsilateral MCAs decreased significantly at 6 months and approached contralateral levels by 2 years post-GKS.
• Pulsatility index (PI) in ipsilateral MCAs increased by 2 years post-GKS, nearing contralateral values.

Findings:

• Transcranial Doppler (TCD) measurements of Vm and PI normalized over time after GKS for AVMs.
• Hemodynamic normalization correlated with the completeness of AVM obliteration confirmed by cerebral angiography.
• Significant hemodynamic improvements were observed even before complete obliteration was evident on imaging.

Implications:

• TCD is a valuable tool for monitoring AVM treatment response after GKS.
• Hemodynamic normalization via TCD can indicate treatment success and guide further management.
• Early hemodynamic changes detected by TCD may predict successful AVM obliteration.