We retrospectively evaluated the relationship between the collateral pathway defined 3D Time-of Flight Magnetic Resonance Angiogram (MRA) and intraoperative cerebral ischemia. As the collateral pathway, ACA collateral and PCA collateral were defined and analyzed. Intraoperative cerebral ischemia was assessed by the continuously monitored electroencephalographic (EEG) change. Internal shunt was inserted routinely. Carotid stump pressure (CSP) was measured through the inserted shunt on all cases.
In the cases except for contralateral carotid occlusion (n=100), incomplete pattern on both ACA collateral and PCA collateral was significantly related to the EEG change and CSP≤25 mmHg (p=0.003, p<0.0001, respectively). Individual evaluations showed the state of ACA collateral was significantly related to the EEG change and CSP≤25 mmHg (p=0.0025, p<0.0001, respectively). Conversely, the state of PCA collateral was not significantly related to them. Therefore, ACA collateral was a major pathway on carotid clamping except for the contralateral carotid occlusion case. Contralateral carotid occlusion (n=10) was significantly related to the EEG change and CSP≤25 mmHg (p<0.0001, p=0.0007, respectively), but no specific pattern of the collateral pathway related to them was found.
Incomplete pattern on ACA collateral and contralateral carotid occlusion might predict intraoperative cerebral ischemia.
