Ultrasonography monitoring with Superb Microvascular Imaging during cerebrovascular surgery.

INTRODUCTION: Ultrasonography (US) is used as a real-time dynamic imaging modality during neurosurgery. A novel Doppler US technique, Superb Microvascular Imaging (SMI), can be used to visualize low-velocity flow of small vessels at high resolution with high frame rates. We visualized vessel flow using this US SMI technique and contrast agent during cerebrovascular surgery. METHODS: Forty-three patients with an unruptured cerebral aneurysm (control), ischemic and hemorrhagic moyamoya disease, carotid artery stenosis, hemangioblastoma, severe stenosis of the middle cerebral artery, venous angioma, and intracerebral hemorrhage (ICH) underwent neurosurgery with US SMI monitoring using a contrast agent. The diameter, length, and number of penetrating vessels were analyzed in patients with an unruptured cerebral aneurysm (control), moyamoya disease, and ICH. RESULTS: Diameter and length of cerebral penetrating vessels were significantly increased in patients with moyamoya disease and ICH compared to control patients. The number of penetrating vessels was increased in moyamoya disease patients compared to control and ICH patients. In hemorrhagic moyamoya disease, flow in the penetrating vessels originated from a deep periventricular point and extended to the cerebral surface. Pulsatile cerebral aneurysms during clipping surgery and carotid artery stenosis during carotid endarterectomy were easily identified by SMI. Drastically increased vessel flow in patients with a hemangioblastoma or a venous angioma was observed. CONCLUSION: Using the US SMI technique and contrast agent, we obtained useful flow information of the vascular disease structure and intracerebral deep small vessels during cerebrovascular surgery. Further quantitative analysis will be informative and helpful for cerebrovascular surgery.

The Early Postoperative Course of Cognitive Function and Preoperative Cerebrovascular Reserve.

BACKGROUND: Patients with severe steno-occlusive disease of a main cerebral artery without causative lesions on magnetic resonance imaging (MRI) often develop cognitive impairment. However, the effects of revascularization surgery and the source of the cognitive impairment remain unclear. Therefore, we investigated the early postoperative course of cognitive function and its association with cerebral blood flow (CBF), cerebrovascular reserve (CVR), white matter disease (WMD), lacunar infarction, and cerebrovascular risk factors. METHODS: Cognitive function was examined using neurobehavioral cognitive status examination (COGNISTAT) in 52 patients with steno-occlusive disease of a main cerebral artery before and at 6 months after superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis. We examined how cognition changed before and at 1, 3, and 6 months after STA-MCA anastomosis in 27 of 52 patients. CVR and CBF were calculated from 123I-N-isopropyl-p-iodoamphetamine single photon emission computed tomography, in addition to other cerebrovascular risk factors in 34 of 52 patients. Cerebral infarction and WMD (periventricular hyperintensity [PVH] and deep subcortical white matter hyperintensity) were also evaluated preoperatively by MRI. RESULTS: COGNISTAT scores improved at 1 month after STA-MCA anastomosis in patients with severe steno-occlusive disease of a main cerebral artery. Multiple stepwise regression analysis revealed that CVR (regression coefficient = -2.237, p = 0.0020) and PVH (regression coefficient = 2.364, p = 0.0029) were the best predictors of postoperative improvement in COGNISTAT scores (R 2 = 0.415; p = 0.0017). CONCLUSION: Cognitive function improves in relation to preoperative CVR and PVH early after STA-MCA anastomosis in patients with steno-occlusive disease of a main cerebral artery.

Superficial Temporal Artery-middle Cerebral Artery Anastomosis for Ischemic Stroke due to Dissection of the Intracranial Internal Carotid Artery with Middle Cerebral Artery Extension.

A 31-year-old man presented with a sudden-onset headache, right hemiparesis, and dysarthria on day 0 and was diagnosed with acute ischemic stroke due to dissection of the left intracranial internal carotid artery with middle cerebral artery extension. His symptoms progressed despite the institution of treatment, suggesting progression of the dissection. On day 5 after symptom onset, the patient underwent superficial temporal artery-middle cerebral artery anastomosis. No new ischemic stroke event occurred after surgery. Cerebral angiography performed 6 months after surgery showed spontaneous resolution of the dissection. The patient recovered to a modified Rankin Scale score of 2 and was able to return to work. The results of the present case suggest that superficial temporal artery-middle cerebral artery anastomosis is an effective treatment for ischemic stroke due to dissection of the intracranial internal carotid artery with middle cerebral artery extension.

Early diagnosis of cerebral ischemia in cerebral vasospasm by oxygen-pulse near-infrared optical topography.

PURPOSE: Early diagnosis of vasospasm is a key factor in the choice of treatment after subarachnoid hemorrhage (SAH). However, a noninvasive method of diagnosing delayed ischemic neurological deficit (DIND) has not been established. We therefore propose a new method of diagnosing cerebral ischemia using near-infrared optical topography (OT) with oxygen inhalation. MATERIALS AND METHODS: We used a 44-channel OT system that covers the bilateral front otemporoparietal areas to assess 29 patients who underwent surgery within 72 h of the onset of SAH. The patients inhaled room air followed by oxygen for 2 min, and then peripheral oxygen saturation (SpO2) was continuously monitored at the index fingertip. The patients were assessed by N-isopropyl-p-[¹²³I]iodoamphetamine (IMP)-SPECT and OT on the same day. Ischemic findings were confirmed using principal component analysis with reference to the systemic SpO2value. RESULTS: Seven of 29 patients developed DIND. Evidence of ischemia was identified by OT in all seven of these patients before the onset of DIND. The OT and SPECT findings agreed in 27 (93 %) of the 29 patients. DISCUSSION AND CONCLUSIONS: Our method might detect cerebral ischemia before the onset of DIND and thus be clinically useful for assessing cerebral ischemia with vasospasm.