Fumihiro Matano

Intraoperative Matas Test Using Microscope-Integrated Intraoperative Indocyanine Green Videoangiography with Temporary Unilateral Occlusion of the A1 Segment of the Anterior Cerebral Artery

OBJECTIVE The aim of the present study was to assess a new technique of surgical microscope-based indocyanine green (ICG) videoangiography (VAG) to confirm the patency of the anterior communicating artery (AcomA) after clipping AcomA aneurysms. METHODS Aneurysmal clipping of five cases of unruptured, broad-neck AcomA aneurysm was performed using the Carl Zeiss Surgical Microscope OPMI Pentero INFRARED 800. RESULTS In all five patients, after clipping AcomA aneurysms, the patency of AcomA was confirmed using ICGVAG findings and temporary unilateral occlusion of the A1 segment of the anterior cerebral artery using temporary clips. Images were excellent and enabled a real-time surgical assessment because the structures of interest, including vessels, perforating arteries, or residual aneurysm neck, were visible to the surgeons eye under the microscope in all five patients. CONCLUSIONS ICGVAG and temporary unilateral occlusion with clips provides a simple, reliable, real-time, and rapid intraoperative assessment of the patency of AcomA. This technique may help to improve the quality of neurosurgical procedures.

Surgical Treatment of 127 Paraclinoid Aneurysms with Multifarious Strategy: Factors Related with Outcome.

BACKGROUND Few reports have been published discussing surgical outcomes of paraclinoid aneurysms using multifarious treatments such as high-flow bypass. MATERIAL AND METHODS We retrospectively analyzed findings from 127 consecutive patients (19 males, mean age at surgery: 56.8 years, range: 19-81 years) at our hospital. The size of aneurysms ranged from 2.7-43.2 mm (mean: 6.9 mm). Extradural anterior clinoidectomy was used to clip small aneurysms. As large or giant aneurysms required a longer temporal occlusion period and often could not undergo simple clipping, high-flow bypass with anterior clinoidectomy or cervical internal carotid ligation was performed to reduce aneurysm blood flow and induce thrombosis. We reviewed a postoperative modified Rankin Scale (mRS), radiographic outcomes, cerebral infarction, and visual disturbance. In addition, we analyzed factors relating to the outcomes and complications, with focus on the aneurysm size, location, and type of surgical treatment. RESULTS Good outcomes were achieved in all patients, as follows: mRS 0:100, mRS 1:16, mRS 2:11, and mRS 3-6:0. Among the 127 patients, complete exclusion of aneurysm was achieved in 119 cases (93.7%). Postoperative morbidity included ischemic lesions in 11 (8.6%) and visual disturbance in 24 (18.8%). Significant statistical differences were observed between ischemic complication and aneurysm size and location (P = 0.0001) and surgical treatment (P < 0.0001). CONCLUSION Surgical treatment of unruptured paraclinoid aneurysm has high efficacy with good outcomes and a high rate of complete exclusion. However, the rate of visual disturbance is relatively high. Careful surgical techniques and intraoperative monitoring are therefore required.

Spontaneous angiographic regression of cerebral arteriovenous malformations: angiographic disappearance is not the real cure.

Angiographically occult arteriovenous malformations (AOAVMs) are poorly understood. AOAVMs include spontaneous regression of cerebral AVMs. Here we discuss spontaneous angiographical regression of cerebral arteriovenous malformations (SRAVM). We present the case of a 34-year-old male patient with SRAVM in whom an arteriovenous (AV) shunt remnant was revealed by intraoperative indocyanine green videoangiography (ICG-VAG). Preoperative angiography indicated spontaneous regression of AVM. We reviewed the literature for articles having specific citations or case histories of SRAVMs. On the basis of our ICG-VAG findings, we confirmed the possibility of an AV shunt remnant being present in patients with SRAVMs. In addition to our own case, we reviewed previously reported cases and analyzed the data from 132 patients with SRAVMs. Ninety-five (72%) such patients received conservative therapy without surgical removal, and 37 (28%) were treated surgically. Only three patients in whom an SRAVM recanalized after 39, 31, and 16 months have been reported. The rate of recanalization in SRAVM including 3 previously reported cases and the present case, is 3.0% (4/132). Intraoperative ICG-VAG can reveal more SRAVMs that recanalize within a short period even if AV shunts are not depicted by angiography. Therefore, surgical removal of the AOAVM should be considered in cases with low surgical risk.

Perioperative complications of superficial temporal artery to middle cerebral artery bypass for the treatment of complex middle cerebral artery aneurysms

OBJECT Only a few studies have reported the risk of ischemic complications occurring when superficial temporal artery (STA) to middle cerebral artery (MCA) anastomosis is performed during surgery for complex MCA aneurysms. SUBJECTS AND METHODS This is a retrospective study of 10 patients (age 52-73) with MCA aneurysms treated with revascularization surgery. The aneurysms were 10-50mm in size (mean: 21mm). We studied the causes and frequency of ischemic complications by analyzing postoperative magnetic resonance imaging. RESULTS Postoperative diffusion-imaging confirmed ischemic complications in six of the 10 patients (in two of the five ruptured aneurysms and in four of the five unruptured). The ischemic complications that observed were infarction of the lenticulostriate artery territory in three cases, cortical infarction in two cases, and cerebral infarction that was likely to be due to cerebral vasospasm in one case. In one case, both cortical infarction and infarction of the lenticulostriate artery territory were observed. The Glasgow Outcome Scale (GOS) scores at the time of discharge indicated good recovery (GR) and moderate disability (MD) in seven cases, severe disability (SD) in two cases, and death (D) in one case. CONCLUSIONS The present study suggests the possibility that STA-MCA anastamosis in surgeries for MCA aneurysms can be performed with comparatively better safety. However, the temporary occlusion time with this surgery is longer than that with a temporary clipping for aneurysmal surgery; thus, we believe that adequate countermeasures are required to prevent ischemic complications.

Quantitative Comparison of the Intraoperative Utility of Indocyanine Green and Fluorescein Videoangiographies in Cerebrovascular Surgery

BACKGROUND A quantitative analysis comparing indocyanine green videoangiography (ICG-VAG) and fluorescein videoangiography (FL-VAG) in cerebrovascular surgery has not been reported so far. OBJECTIVE To clear the differences of characteristics of ICG-VAG and FL-VAG by quantitative assessment. METHODS We prospectively analyzed results from 23 patients (3 males; mean age at surgery: 60.9 years, range: 14-75 years) at our hospital from August 2014 to July 2015. Eighteen patients had cerebral aneurysms for clipping, and 5 had intracranial arterial stenosis for superficial temporal artery (STA)-middle cerebral artery bypass. We imported data from the operative image data, converted by Audio Video Interleave to Aquacosmos as picture fluorescence intensity-analyzing software. Regions of interest were set at the parent artery, dome of aneurysms, and perforating artery in cases of clipping of aneurysms, and setting at 3 points in STA, in case of bypass. The transition of fluorescence intensity at each region of interest was calculated and plotted using Aquacosmos. RESULTS Thick-walled artery, such as parent artery ( P = .0017) and STA ( P = .0182), was more significantly visualized by ICG-VAG than FL-VAG, whereas the perforating artery, especially in deep surgical fields, such as anterior communicating artery, internal carotid artery, and basilar artery, was better visualized by FL-VAG than ICG-VAG ( P < .0001). CONCLUSION In this quantitative analysis of fluorescence study, ICG-VAG showed greater efficacy than FL-VAG in visualizing relatively thick arteries, such as parent artery and STA. However, FL-VAG has greater efficacy than ICG-VAG in visualizing perforating artery, especially in deep surgical fields with characteristic vessel walls.

Intracerebral Hemorrhage Caused by Cerebral Hyperperfusion after Superficial Temporal Artery to Middle Cerebral Artery Bypass for Atherosclerotic Occlusive Cerebrovascular Disease

Few papers have reported detailed accounts of intracerebral hemorrhage caused by cerebral hyperperfusion after superficial temporal artery to middle cerebral artery bypass (STA-MCA) bypass for atherosclerotic occlusive cerebrovascular disease. We report a case of vasogenic edema and subsequent intracerebral hemorrhage caused by the cerebral hyperperfusion syndrome (CHS) after STA-MCA bypass for atherosclerotic occlusive cerebrovascular disease disease without intense postoperative blood pressure control. A 63-year-old man with repeating left hemiparesis underwent magnetic resonance angiography (MRA), which revealed right internal carotid artery (ICA) occlusion. We performed a double bypass superficial temporal artery (STA)–middle cerebral artery (MCA) bypass surgery for the M2 and M3 branches. While the patient’s postoperative course was relatively uneventful, he suffered generalized convulsions, and computed tomography revealed a low area in the right frontal lobe on Day 4 after surgery. We considered this lesion to be pure vasogenic edema caused by cerebral hyperperfusion after revascularization. Intravenous drip infusion of a free radical scavenger (edaravone) and efforts to reduce systolic blood pressure to <120 mmHg were continued. The patient experienced severe left hemiparesis and disturbance of consciousness on Day 8 after surgery, due to intracerebral hemorrhage in the right frontal lobe at the site of the earlier vasogenic edema. Brain edema associated with cerebral hyperperfusion after STA-MCA bypass for atherosclerotic occlusive cerebrovascular disease should be recognized as a risk factor for intracerebral hemorrhage. The development of brain edema associated with CHS after STA-MCA bypass for atherosclerotic occlusive cerebrovascular disease requires not only intensive control of blood pressure, but also consideration of sedation therapy with propofol.

Pathophysiology and management of intracranial arterial stenosis around the circle of Willis associated with hyperthyroidism: case reports and literature review.

Cases of moyamoya disease or intracranial arterial stenosis around the circle of Willis (M/IAS) associated with hyperthyroidism have been reported. However, most of these previous reports were of the ischemic form of M/IAS and primary hyperthyroidism. To the best of our knowledge, no studies have documented therapy for M/IAS associated with hyperthyroidism. We discuss four previously unreported cases, including those involving the intracerebral hemorrhage form and thyroid-stimulating hormone (TSH) secretion from a pituitary adenoma (secondary hyperthyroidism). We analyzed data from 52 previously reported cases, including the 4 cases presented here, and discuss M/IAS associated with hyperthyroidism, treatment options, pathophysiology, the ischemic and hemorrhagic forms, secondary hyperthyroidism, and the relevant literature. Hyperthyroidism results in thyrotoxicosis and the stimulation of the superior cervical ganglion by TSH antibodies and f-T3/f-T4. Consequently, hypercoagulability and stenosis of the cerebral artery can occur. There are many reports of ischemic M/IAS associated with hyperthyroidism. A conservative approach to treatment is important in such cases; for example, antithyroid therapy should be the first choice to treat ischemic M/IAS. There have been only a limited number of reports on hemorrhagic M/IAS. We presume that hemorrhagic M/IAS tears the weakened vasculature in a manner similar to that of normal M/IAS (with no complicating hyperthyroidism). The authors also reported M/IAS associated with secondary hyperthyroidism due to pituitary thyroid secreting hormone secreting adenoma.

Microcystic Meningioma with Late-phase Accumulation on Thallium-201 Single-photon Emission Computed Tomography: Case Report

Microcystic meningiomas are rare but benign brain tumors. Previous reports have shown that Thallium-201 single-photon emission computed tomography (201Tl SPECT) demonstrated a higher late-phase accumulation of 201Tl in malignant or recurrent meningiomas than in nonaggressive meningiomas. No study has reported 201Tl SPECT findings in microcystic meningiomas. We here describe a case of a microcystic meningioma with a high 201Tl SPECT retention rate in a 62-year-old woman who complained of headache. Computed tomography revealed an intracranial tumor in the right frontal lobe. Moreover, 201Tl SPECT revealed a high uptake of 201Tl in the tumor, which was particularly prominent in the delayed phase. The uptake index on an early image was 1.46 and that on a delayed image was 1.35. Therefore, the retention index was 0.92. After 2 years of tumor growth, we performed successful radical resection, and histological examination revealed the presence of a microcystic meningioma. Therefore, we concluded that 201Tl SPECT may be useful for the preoperative diagnosis of microcystic meningiomas and that late-phase accumulation of 201Tl is not a specific finding of malignant brain tumors. Therefore, we need to be careful in the evaluation and judgment of high retention in a delayed image of 201Tl SPECT.

Reversible cerebral vasoconstriction syndrome associated with subarachnoid hemorrhage triggered by hydroxyzine pamoate

Abbreviations: CBF, cerebral blood flow; CT, computed tomography; CTA, comuted tomography angiography; FLAIR, fluid-attenuated inversion recovery; IMP, -isopropyl[123I]-p-iodoamphetamine; MRA, magnetic resonance angiography; RI, magnetic resonance imaging; RCVS, reversible cerebral vasoconstriction synrome; SAH, subarachnoid hemorrhage; SPECT, single photon emission computed omography. ∗ Corresponding author at: Department of Neurosurgery, Nippon Medical School, -1-5 Sendagi, Bunkyo-ku, Tokyo 113-8603, Japan. Tel.: +81 3 3822 2131; ax: +81 3 5685 0986. E-mail addresses: shunchan.ryouchan@gmail.com, s00-078@nms.ac.jp, 00-080@nms.ac.jp (F. Matano).

3.0-T diffusion images after clipping of middle cerebral artery aneurysm.

AIM Replacement of aneurysm clips or temporary parent artery occlusion during aneurysm clipping (AC) carries the risk of inducing postoperative neurologic deficits. When studying the risk of surgical complications associated with cerebral aneurysms, patients with similar conditions should be compared to eliminate the influence of rupture and location of aneurysm. MATERIAL AND METHODS We used 3.0-Tesla (3.0T) magnetic resonance diffusion-weighted imaging (DWI) and magnetic resonance angiography (MRA) to analyze surgical complications after AC. A total of 42 AC procedures for 40 unruptured and 2 delayed-phase ruptured MCA aneurysms were evaluated. RESULTS In six patients, temporary parent artery occlusion was performed. Asymptomatic hyperintensities were observed on DWI of three patients. In one patient, an asymptomatic lesion was most likely caused by a small contusion that occurred during dissection of an aneurysm attached to the brain surface. In two patients, asymptomatic cortical lesions were caused by brain surface contusions due to lacerations of the open dura. No symptomatic hyperintensities on DWI were observed after surgery. No fixed ischaemic neurologic deficits resulted from AC. CONCLUSION Although some postoperative abnormalities were observed with 3.0T DWI, we found clipping of MCA aneurysms to be a safe procedure with a low risk of ischaemic complications.