Usefulness of intraoperative laser Doppler flowmetry and thermography to predict a risk of postoperative hyperperfusion after superficial temporal artery-middle cerebral artery bypass for moyamoya disease.

We investigated whether postoperative hyperperfusion in moyamoya disease can be predicted using intraoperative laser Doppler flowmetry and/or thermography. A prospective study was conducted on 27 patients (39 hemispheres) with moyamoya disease who underwent superficial temporal artery-middle cerebral artery (STA-MCA) bypass. During surgery, regional cerebral blood flow (rCBF) was measured with a laser Doppler flowmeter and the temperature of the cortical surface was measured with an infrared thermograph. Postoperative hyperperfusion was assessed immediately after surgery based on CBF study under sedation (propofol) as >100% increase in corrected rCBF compared to preoperative values. Postoperative hyperperfusion on CBF was observed in two patients (7.4%). A significant correlation was observed between intraoperative rCBF changes and postoperative rCBF increase (Pearson's method: r=0.555, p=0.0003; simple regression: Y=1.22X+3.289, r (2)=0.308, p=0.0004). Furthermore, the rCBF changes measured by laser Doppler flowmetry were significantly greater in patients with postoperative hyperperfusion (p=0.0193) and CHS (p=0.0193). The present study suggests that intraoperative rCBF measurement using laser Doppler flowmetry may predict a risk of post-EC-IC bypass cerebral hyperperfusion in moyamoya disease.