Cerebrovascular neurosurgeons at Stanford University, led by Professor and Department Chair of Neurosurgery Dr. Gary Steinberg, treat their moyamoya patients through direct intraoperative revascularization of the affected territory with an extracranial to intracranial (EC-IC) superficial temporal artery (STA) to middle cerebral artery bypass (MCA).

In the large single-center study for direct revascularization for moyomoya, Stanford clinicians compiled hemodynamic data from 18 years (496 revascularization procedures in 292 patients) who underwent surgical revascularization to treat moyamoya disease. The data were analyzed retrospectively.

Fivefold Increase in Flow after Revascularization

The clinicians found that, before revascularization, mean blood flow in the cerebral recipient vessel was, on average, 4.4 +0.26 ml/min. After bypass augmentation, blood flow increased fivefold to an average mean flow of 23.9 +1.0 mL/min. They also found that the diameter of the STA bypass conduit was the main determinant for blood flow augmentation. High post-anastomosis middle cerebral artery (MCA) flow was associated with postoperative hemorrhage and transient neurologic deficits.

Both before and after completion of the EC-IC bypass, STA and MCA blood flow is measured with the Transonic Charbel Micro-Flowprobe^® and is recorded in the patient’s record. This data was retrospectively analyzed for this landmark study. The results of the study—the fivefold increase in flow—attest to the value of direct revascularization through an STA-MCA bypass to alleviate the effects of occlusive moyomoya disease by increasing blood flow to the affected territories of the brain. Secondly, the study demonstrated that measuring blood flow intraoperatively for hemodynamic assessment is integral to the direct revascularization protocol.

REFERENCE
Lee M, et al, “Intraoperative blood flow analysis of direct revascularization in patients with moyamoya disease,” J Cereb Blood Flow Metab. 2011 Jan;31(1):262-74.