Carotid endarterectomy (CEA) is a surgical procedure with proven efficacy against carotid artery stenosis. In order for surgery to be classified as advantageous over medical treatment, the technique must have a guaranteed lo complication rate. To ensure the safety and reliability of CEA, surgeons must perform risk evaluation of surgery by preoperative diagnostic imaging; furthermore, during surgery, the surgeons must define a sufficient surgical field, perform an accurate dissection based on anatomical knowledge, and perform protective manipulation of the arteries, including carotid plaques. Furthermore, reliable hemostasis and arterial suturing are important because the surgery is performed with continuous antiplatelet agents.

Background: Carotid endarterectomy (CEA) carries the risk of cerebral ischemia due to cross-clamping; however, the use of a shunt can effectively avoid this. At our institute, CEA following a standardized shunt procedure is routinely performed. In this study, we describe the treatment methods and results.

Methods: From April 2013 to March 2020, we used a shunt in 186 patients who underwent CEA at our institute. Cerebral ischemia was evaluated using intraoperative somatosensory evoked potential (SEP), and by determining the presence of symptomatic cerebral infarction.

Results: Shunt placement was difficult in four cases (2.2%). The average clamping time to insert the shunt was 4.4 min, and the removal-reperfusion time was 7.3 min. Intraoperative SEP reduction was observed in 15 patients (8.1%); however, postoperative cerebral infarction occurred in only one patient (0.5%). No obvious complications due to shunt use were observed.

Conclusions: CEA with shunt placement following the standardized procedure is a safe and secure method for surgeons.

Objective: We investigated the hypotheses that, when carotid artery stenting (CAS) is performed for soft plaques, the balloon used for predilatation should be close to the normal blood vessel diameter, and, furthermore, plaque scattering can be prevented by sufficiently aspirating blood before releasing protection. We report a representative case of 12 consecutive patients with soft plaques who underwent CAS using this method.

Methods: CAS was performed in 12 consecutive patients who showed a high degree of preoperative black blood (BB) on magnetic resonance imaging (MRI). Balloon protection was close to the diameter of normal blood vessels and was placed in the distal internal carotid artery or the common carotid artery. A closed-cell stent was the first choice.

Results: One of the 12 patients had cerebral infarction in a region unrelated to the treated vessel. Eleven patients showed no new neurological deficits after CAS. One patient had plaque protrusion during surgery; therefore, a closed cell stent was added, and no postoperative complications were noted.

Conclusion: Our method can be safely used for soft plaques.

It is important to confirm the epileptogenic nature of a cavernous angioma before performing epilepsy surgery. Although some patients with epilepsy have cavernous angiomas, the lesions may not always be responsible for their seizures, and resection may not result in postoperative seizure control.

For such patients, when the ictal symptoms are consistent with the localization of the cavernous angioma on both magnetic resonance imaging (MRI) and electroencephalography (EEG), the angioma may be considered epileptogenic. However, if the ictal symptoms are not consistent with imaging and EEG findings, simultaneous video-EEG recordings of the seizures or events can be useful. Intracranial electrocorticography recordings may also help to accurately verify the relationship between the electrical seizure onset and the localization of the cavernous angioma on MRI.

Considering the surgical strategies for the management of a cavernous angioma, it is important to not only resect the angioma itself but the surrounding hemosiderin deposits as well, which, according to several reports, are epileptogenic. When the cavernous angioma is located apart from eloquent areas such as the primary motor, sensory, and language cortices, the whole gyrus, including the cavernous angioma, can be removed. Further, when the cavernous angioma is located in the medial temporal lobe, resection of the hippocampus and amygdala, as well as the angioma, is likely to improve seizure outcomes in patients.

Subarachnoid hemorrhage (SAH) is an acute systemic event that not only affects the central nervous system but also other vital organs, especially in severe cases. Neuroresuscitation, as well as respiratory and circulatory stabilization, are essential prerequisites for radical aneurysm repair.

Poor outcomes in SAH are mainly caused by early brain injury (EBI) within 72 h of its onset. At our institution, we immediately start therapeutic hypothermia targeted at 33.5°C to mitigate EBI and accomplish radical treatment for a ruptured aneurysm for eligible patients, that is, patients with Grade V of the World Federation of Neurological Surgeons grading system, are under 75 years old, and whose pupils are not fixed and dilated. After maintaining a core temperature of 33.5°C using the surface cooling method for 3 days, patients are rewarmed at a rate of 1°C/day or slower. When the temperature reaches 36°C around Day 7, an endovascular cooling system is applied to maintain normothermia during the high-risk period of delayed cerebral ischemia until Day 14. Cardiopulmonary function, intravascular volume, blood glucose, serum electrolytes, and other parameters are carefully assessed and managed according to the recommendations of the Neurocritical Care Society's Multidisciplinary Consensus Conference. Shivering should be assessed and treated according to the protocol. Brain function was monitored using a simplified continuous amplitude-integrated electroencephalogram. The frequency and duration of fever above 38°C and cerebral infarction significantly decreased, and the rate of good outcome (good recovery and moderate disability, assessed by the Glasgow Outcome Scale at 6 months), showed a trend toward improvement from 32% to 55% after the introduction of endovascular fever control. Our attempts suggest that active temperature management together with neurocritical care is safe and beneficial.

Mechanical thrombectomy (MT) for emergent large vessel occlusion (ELVO) of the internal carotid artery and the M1 segment of the middle cerebral artery can improve patient prognosis compared to medical therapy alone. Although a high recanalization rate of approximately 90% has been reported for MT using a stent retriever (SR) or aspiration catheter (AC), in actual clinical practice, we sometimes encounter complex cases that require recanalization using conventional MT techniques due to anatomical factors and the complexity of the lesion. This article presents several complex cases of MT, describing the following six typical conditions that are likely to be encountered clinically and discussing the therapeutic strategies and techniques for these complicated lesions in the literature: (1) difficulty accessing the lesion due to tortuous vessel anatomy, (2) carotid artery and intracranial tandem lesion, (3) distal lesions beyond the M2 segment of the middle cerebral artery, (4) vertebra-basilar artery occlusion, (5) intracranial atherosclerotic stenosis (ICAS), and (6) cerebral artery dissection.

We generally adopted a combined technique with SR and AC as the first choice for these procedures. The advantages of this combined technique are as follows: (1) embolization in a new territory (ENT) is reduced by tightly catching the thrombus with both the SR and AC; (2) because the axis of the AC is aligned with the axis of the parent artery due to the distally placed stent, there is less vascular damage due to branch vessel withdrawal during SR retraction; and (3) distal advancement of the AC is facilitated by anchoring the SR distally. To improve patient outcomes, surgeons should aim to achieve complete recanalization at one pass (FPE: first-pass effect) using various treatment strategies and techniques adapted to the situation.

As the number of patients undergoing maintenance dialysis (MD) increases over time, the number of those with unruptured intracranial aneurysms is also assumed to increase. Treatment results and perioperative measures for unruptured intracranial aneurysmal clipping with MD at our hospital have been reported. Ten patients (11 surgeries) with MD treated by clipping of unruptured intracranial aneurysms in 17 years from January 2002 to December 2018 were examined. Clipping was completed in all cases. Of the 11 procedures, postoperative morbidity was observed in eight cases (73%). Among them, the most common complication was acute symptomatic seizure in seven patients (64%). The onset of acute symptomatic seizures was limited to within two days after surgery, and there were no prolonged cases. We concluded that patients undergoing aneurysmal clipping on MD are more likely to have postoperative acute symptomatic seizures than those without MD. Therefore, perioperative measures and informed consent focusing on the risk of postoperative seizures are required.

A 53-year-old man presented to our hospital with a chief complaint of headache with no neurological deficit. Computed tomography (CT) showed subarachnoid hemorrhage in the left ambient cistern. Cerebral angiography revealed a fusiform-shaped aneurysm at the origin of the left vertebral artery (VA). We performed endovascular treatment using stent with coiling. Left VA angiography showed the anterior spinal artery arising from the middle part of the true lumen and revealed contrast material retrograde inflow into the pseudo-lumen from the distal potion of the dissection. Therefore, we introduced a microcatheter to the left VA across the right VA and the entry at the distal side of the aneurysm, embolized the pseudo-lumen, and concomitantly deployed the stent from the left VA to the true lumen of the dissection to preserve the anterior spinal artery. After coil embolization of the aneurysm, the anterior spinal artery was preserved, and the parent artery was well reconstructed. Despite persistent truncal ataxia, the patient has been subjected to follow-up as an outpatient (modified Rankin Scale score: mRS 2) and remains recurrence-free three months postoperatively.

We report a case of progressive cerebral infarction due to middle cerebral artery (MCA) stenosis treated with balloon percutaneous transluminal angioplasty (PTA), followed by superficial temporal artery -to-middle cerebral artery (STA-MCA) bypass.

An 82-year-old man was admitted to our hospital for sudden left hemiparesis. Magnetic resonance imaging (MRI) demonstrated severe stenosis in his right MCA and multiple cerebral infarctions in the corresponding region. In spite of our initial aggressive medical management, the patient presented with left hemispatial neglect on day five. MRI showed enlarged lesions. Accordingly, we conducted urgent balloon PTA in order to avoid aggravation. Although the MCA was dilated sufficiently, restenosis was a concern from a long-term perspective because the lesion was longer than 10 mm. Therefore, we added STA-MCA bypass subsequently on day 11. No further infarction was detected after both treatments. The patient was discharged after four months of rehabilitation. Computed tomography angiography (CTA) on day 90 showed restenosis of the MCA. These observations suggest that early STA-MCA bypass may have prevented stroke progression.

Objective: Patients with moyamoya disease frequently develop ischemic and/or hemorrhagic events. A small number of patients with moyamoya disease, most of which are children or young adults, generate involuntary movements as an initial manifestation. However, the characteristics and clinical features are less known. In this case report, we present a geriatric case of moyamoya disease presenting with hemiballismus as a primary symptom, and a favorable clinical course achieved with oral haloperidol (D2 receptor antagonist).

Case presentation: A 79-year-old female developed unvoluntary choreoathetoid movement in the right upper and lower extremities. The gradually worsening symptom was accompanied with ballismus in two months. Head MR showed bilateral stenosis and occlusion of the terminal portions of the internal carotid arteries without any definitive destructive brain lesions. Abnormal vascular network at the base of the brain, so called moyamoya vessels, was confirmed in cerebral angiography. Moyamoya disease was diagnosed with these typical findings. After administration of haloperidol, the patient’s involuntary movement gradually disappeared.

Conclusion: Even though geriatric moyamoya with involuntary movement as an initial manifestation is extremely rare, meticulous evaluation including magnetic resonance (MR) is needed. We concluded that pharmacotherapy with a D2 receptor antagonist was adequate for symptom improvement, especially for the geriatric case that is not suitable for invasive vascular reconstructive surgery.

Delayed onset multiple white matter lesions is a rare pathology that has been reported in patients after endovascular coiling of cerebral aneurysms. This pathology was reportedly caused by nickel allergies or foreign body embolization of polyvinylpyrrolidone. Here, we report a case of white matter lesions in a patient which was diagnosed as a nickel allergy based on a positive reaction to the skin patch test. Steroid therapy improved symptoms and magnetic resonance imaging findings immediately. Clinical differential diagnosis of delayed multiple white matter lesions is difficult. Although biopsy is useful for obtaining a diagnosis, a skin patch test can also be helpful.

Superficial temporal artery to middle cerebral artery (STA-MCA) bypass surgery is currently widely performed for the prevention of the recurrence of occlusive cerebrovascular disease. In fact, the Japanese extracranial-intracranial (EC-IC) bypass Trial (JET study) has proved the superiority of EC-IC bypass surgery. STA-MCA bypass surgery is based on right-left handling and coordination and is the first microscopic procedure that young neurosurgeons should learn.

Flow diversion (FD) has become mainstream for cavernous carotid aneurysm (CCA) treatment owing to its high occlusion/low complication rate. Nevertheless, retreatment, including open surgery, is needed in some cases. To safely achieve open surgery, traditional balloon test occlusion (BTO) has been performed preoperatively. However, BTO has potential disadvantages such as patient burden and vascular access site complications. We devised a novel technique—intraoperative test occlusion—to evaluate ischemic tolerance intraoperatively. While the cervical internal carotid artery is occluded for 15 minutes, ischemic tolerance is evaluated using somatosensory evoked potential (SEP)/motor evoked potential (MEP). Herein, we present a case of CCA who developed progressive oculomotor nerve palsy after FD. Following low-flow bypass, intraoperative test occlusion was performed. After confirmation of unchanged SEP/MEP, the cervical internal carotid artery was ligated. The postoperative course was uneventful. Our surgical strategy may reduce patient burden and BTO-related complications. Further investigations are warranted to fully demonstrate the usefulness of intraoperative test occlusion.