Occurence and Variability in Acute Formation of Leptomeningeal Collaterals in Proximal Middle Cerebral Artery Occlusion

Abstract

Background: We performed this study to semi-quantitatively characterize the formation of leptomeningeal collaterals in acute middle
cerebral artery (MCA) occlusion caused by intravascular balloon inflation.
Methods: The anatomic extent of leptomeningeal collateral blood flow from the anterior cerebral artery territory to the MCA territory
during occlusion of the M1 segment was graded based on angiographically visible retrograde reconstitution of the MCA segments on
the delayed venous phase prior to and during inflation of the balloon.
Results: During MCA occlusion, the leptomeningeal collaterals markedly improved in 5 of 7 patients and were graded as 1 (retrograde
filling of distal M1 segment) in 3 patients, 2 (retrograde filling of proximal M2 segment) in 1 patient, 4 (retrograde filling of M3 segment) in 1 patient and 5 (none or minimal) in 2 patients.
Conclusion: Leptomeningeal collaterals from the anterior cerebral artery can form rapidly during MCA occlusion with considerable
individual variability.