Postoperative vascular event prediction using angiography and ultrasonography in patients with Moyamoya disease.

OBJECTIVE

Indirect revascularization surgery reduce the risk of recurrent vascular events in patients with moyamoya disease (MMD), but the roles of postoperative angiography and ultrasonography in predicting these events remain unclear.

METHODS

This prospective study enrolled patients with MMD who would undergo their first unilateral indirect revascularization surgery. They received preoperative and postoperative ultrasound examination at 1, 3, and 6 months and conventional cerebral angiography. On ultrasonography, postoperative emerging flow (PEF) in an intracranial artery was defined as emerging flow postoperatively with absence of flow preoperatively. Predictors of vascular event frequency reduction were identified from angiographic and ultrasonographic parameters.

RESULTS

In total, 52 patients (including 24 pediatric and 24 male patients), who underwent 52 preoperative and 82 postoperative ultrasound examinations, were enrolled. Significant postoperative changes were noted in all the ultrasonographic parameters of ipsilateral superficial temporal artery (STA) and the end-diastolic velocity and flow volume in contralateral STA. During a median follow-up of 5.3 years, indirect revascularization surgery significantly reduced the occurrence of ipsilateral vascular events. Predictors of vascular event frequency reduction included Matsushima grade A or B on the ipsilateral side on angiography (odds ratio [OR] = 22.00, P = 0.002) and lower resistance index (RI) in ipsilateral STA (OR = 0.0001, P = 0.012) but no PEF pattern in ipsilateral middle cerebral artery (OR = 0.14, P = 0.029) on ultrasonography performed within 6 months.

CONCLUSIONS

Reduction of long-term vascular event frequency probably can be predicted through postoperative angiography and ultrasonography within 6 months after indirect revascularization surgery.