Semi-Quantitative Assessment of Regional Cerebral Blood Flow Changes Following Extracranial-Intracranial Bypass Using...

Area of Science:

• Neurosurgery
• Neuroradiology
• Cerebrovascular Surgery

Background:

• Extracranial-intracranial (EC-IC) bypass, specifically STA-MCA anastomosis, is utilized to enhance cerebral blood flow in patients with moyamoya disease or atherosclerotic steno-occlusive conditions.
• Assessing the impact of STA-MCA bypass on regional cerebral perfusion is crucial for optimizing patient outcomes.

Purpose of the Study:

• To evaluate the effect of STA-MCA bypass on regional cerebral perfusion using a semi-quantitative SPECT area-based method.
• To determine changes in perfusion in the basal ganglia and temporal regions post-bypass.

Main Methods:

• A cohort of 15 patients with complete pre- and postoperative CTA and SPECT data were analyzed.
• Semi-quantitative SPECT imaging was used to calculate the proportional perfusion area in the basal ganglia and temporal regions.
• Image analysis involved Labelme annotation, Canny edge detection, and Green's theorem, normalized to total brain area.

Main Results:

• Postoperative SPECT revealed a significant increase in perfusion area in the basal ganglia (p=0.0003) and temporal regions (p=0.012).
• All 16 STA-MCA anastomoses were patent.
• No significant difference was observed between ipsilateral and contralateral basal ganglia perfusion improvements in unilateral cases (p=0.839).

Conclusions:

• STA-MCA bypass is associated with significant improvements in semi-quantitative cerebral perfusion, particularly in the basal ganglia.
• The observed perfusion changes may indicate a global hemodynamic effect, though this requires further research.
• The SPECT-based method is feasible for perioperative monitoring but needs further validation in larger studies.