Analysis of Cerebral Perfusion and Vascular Reserve after Combined Revascularization for Moyamoya Disease

Background and purpose: Moyamoya disease is a progressive occlusive disease of the cerebral arteries. Various vascular reconstruction surgeries have been reported, but the most appropriate procedure remains unclear. We have preferred to perform a combined direct and indirect bypass to the Rolandic region to prevent ischemic stroke. The purpose of this study was to evaluate the surgical results of our method using cerebral blood flow (CBF) from single photon emission computed tomography (SPECT). Methods: This study examined 29 hemispheres in 21 patients (6 males, 15 females; mean age, 33.25 ± 19.26 years; range, 9-67 years). All patients underwent combined vascular reconstruction using a superficial temporal artery (STA) -middle cerebral artery (MCA) anastomosis and encephaloduromyosynangiosis. Regional CBF (rCBF) and cerebrovascular reserve (CVR) were measured using N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) SPECT before and after the procedure. Results: Postoperatively, 28 direct bypasses were patent, but one became occluded within 3 months after surgery. Preoperative symptoms completely resolved in all except one case. Three months postoperatively, improvement of rCBF at rest was not evident in the ipsilateral frontal lobe after surgery, but CVR was widely and significantly improved in the frontal lobe involving the motor cortex (preoperative CVR, -1.1 ± 16.1%; postoperative CVR, 14.3 ± 19.7%, p<0.001) and premotor area (preoperative CVR, -2.14 ± 15.9%; postoperative CVR, 10.2 ± 15.9%, p<0.001). Conclusions: Our combined direct and indirect bypass effectively reduced ischemic symptoms of moyamoya disease and increased CVR. The possibility that transient ischemic attack was more strongly affected by CVR than by CBF was suggested.