Local cortical cerebral blood flow and response to carbon dioxide during anesthesia in patients with moyamoya disease.

PURPOSE: The CO(2) reactivity of cortical cerebral vessels and local cortical blood flow (l-CoBF) were evaluated during anesthesia in patients with moyamoya disease who were undergoing revascularization surgery.

METHODS

Using laser-Doppler flowmetry, the CO(2) reactivity of cortical cerebral vessels and l-CoBF were measured continuously in five patients at the local surgical field of the middle cerebral artery (MCA) territory.

RESULTS

Local-CoBF values obtained during the normocapnic condition varied from site to site of gyrus in the MCA region (0-73 ml. 100 g(-1).min(-1)). Local-CoBF was maximal at 39-43 mmHg of the PaCO(2) range, and decreased above and below this range. The response of l-CoBF to CO(2) was larger at the sites where the maximal level was obtained during normocapnia. In two patients, l-CoBF decreased by about 50%, and remained law even 40 min after administration of acetazolamide.

CONCLUSION

In patients with moyamoya disease, l-CoBF values obtained during the normocapnic condition varied from site to site of gyrus, and not only hypocapnia but also hypercapnia decreased l-CoBF within the MCA region.