Introduction: Although improvements in endovascular treatment have decreased the frequency of bypass surgery, cerebral vascular reconstructions are still important. Many critical points are required to achieve a reliable bypass patency. We describe our experience and techniques for bypass surgery, especially focusing on the superficial temporal artery to middle cerebral artery (STA-MCA) bypass.
Materials and methods: Over a period of 5 years, STA-MCA bypass was performed for 42 patients with atherosclerotic internal carotid artery or middle cerebral artery occlusion, or hemodynamic ischemia; 35 patients with moyamoya disease; and 97 patients with complex cerebral aneurysms. Mean occlusion time, bypass patency, hyperperfusion, ischemic complication, and postoperative delayed wound healing were assessed.
Results: Within 42 ischemic cases, the mean occlusion time of the STA-MCA procedure was 20 minutes 16 seconds. No ischemic complications due to temporal occlusion occurred. Acute bypass occlusion (occlusion within 2 weeks after operation) occurred in 1 case of STA-MCA for moyamoya disease and 1 case of STA-MCA bypass for a patient with ischemic occlusion. Perioperative ischemic stroke was observed in 4 patients with ischemic occlusion and 1 patient with moyamoya disease.
Conclusion: To perform a safe and reliable vascular reconstruction, off-the-job training, a bloodless operative field, selection of an appropriate donor and recipient artery, use of the “fish mouth” method for trimming the donor artery, and an intima-to-intima everting suture are necessary.

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Because of a high tendency toward rebleeding, we treat all ruptured aneurysms of the anterior wall of the supraclinoid internal carotid artery (ICA) with trapping of the rupture site through vascular reconstruction of the distal internal carotid artery. However, according to the site and size of a ruptured aneurysm, some patients are treated with trapping of the posterior communicating artery (PCoA) or proximal clipping of the ICA to create a blind end. We reviewed and analyzed the clinical records of 12 patients treated between 2009 and 2015 at our hospital. We divided aneurysm locations into 3 types. Four patients with an aneurysm located between the origin of the ophthalmic artery and PCoA (Type 1) were treated with trapping between the cervical ICA and the ICA distal to the aneurysm. Four patients with an aneurysm located on the opposite wall at the origin of the PCoA (Type 2) were treated with trapping that included the origin of an adult type PCoA. Among 4 patients with an aneurysm located distal to the PCoA (Type 3), 2 were treated with clipping of the ICA proximal to the PCoA, and 2 were treated with direct fenestrated clipping. Only 1 patient (Type 3) had a postoperative ischemic complication. In conclusion, surgical outcomes of bypass and trapping for treating ruptured anterior wall ICA aneurysms were favorable, but the management of Type 3 aneurysms remains challenging.

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With aging of the population in Japan, the incidence of aneurysmal subarachnoid hemorrhage (SAH) has been increasing among the elderly. We analyzed the outcomes of SAH in patients over 75-years-old. We retrospectively evaluated medical records and imaging studies of 124 patients treated with clipping, coiling, or conservative therapy between January 2000 and December 2015. Patient ages ranged from 75 to 96 years (average, 80.4 years). Thirteen patients were male (10.5%). The patients were graded on admission according to the Hunt and Kosnik (H/K) scale, and the modified Rankin scale (mRS) at discharge.
Eighty-four patients (67.7%) underwent coil embolization, and 31 (25%) underwent surgical clipping. Nine patients (7.3%) received conservative therapy. The mortality rate of surgically treated patients was only 6.1%, even though the overall mortality rate was 10.5%. For assessment of factors related to outcomes, 115 surgically treated patients were divided into a good outcome group (mRS 0-2, n=43) and a poor outcome group (mRS 3-6, n=72). A preoperative low H/K grade of 1-3 was significantly associated with outcomes (95.3% in the good outcome group versus 55.6% in the poor outcome group, p<0.001). Findings of intracerebral hematoma, intraventricular hemorrhage, and acute hydrocephalus on initial computed tomography were also significantly associated with a poor outcome.
Radical surgical treatment resulted in low mortality and good outcomes, even in patients aged over 75-years-old, especially those with a low preoperative H/K grade.

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Fever in subarachnoid hemorrhage (SAH) is associated with vasospasm and poor outcome. To mitigate early brain damage in SAH, we have been treating World Federation of Neurological Surgeons (WFNS) Grade 5 patients with rapid induction of therapeutic hypothermia (TH) initiated immediately following onset of SAH and continued for approximately 7 days. Management after rewarming has been problematic. Rebound fever, especially during the period of post-SAH vasospasm, may increase the risk of cerebral infarction. We prospectively studied the feasibility and safety of endovascular cooling for maintaining prophylactic normothermia following initial TH in patients with severe SAH.
TH (core body temperature 34.0°C) using surface cooling was initiated immediately after a diagnosis of WFNS Grade 5 SAH was made. All ruptured aneurysms were surgically clipped as soon as possible within 6 hours after arrival. At approximately postoperative day 7, after rewarming to 36°C, an endo- vascular catheter with 2 cooling balloons (Cool Line^® Catheter, Asahi Kasei ZOLL Medical Corp., Tokyo, Japan) was inserted into the left internal jugular vein and connected to the Thermogard XP^® Temperature Management System (Asahi Kasei ZOLL Medical Corp.) for the following 7 days. Temperature recordings in 11 SAH patients immediately before the period of endovascular cooling served as the control.
Eleven patients (6 women; mean age of 63.8 ± 6.4 years [range, 50-73 years]) were enrolled in the study. Endovascular cooling was initiated at 7.9 ± 1.4 days (range, 6-11 days) after admission and continued for 6.7 ± 0.9 days (range 4-7 days). Unfavorable outcomes were associated with minimal shivering and good temperature control, whereas favorable outcomes were associated with vigorous shivering and increased temperature. Nine patients manifested shivering with increased temperature and were treated with acetaminophen, dexmedetomidine, and/or propofol. During the study period, two patients developed fevers above 38°C, and 8 of 11 patients without endovascular cooling developed fevers (p=0.03, two-tailed Fisher's exact test). There was no evidence of cerebral infarction related to vasospasm during endovascular cooling, and no catheter-related sepsis or thromboembolic events. In one patient, fasudil hydrochloride was administered intra-arterially for angiographic vasospasm, resulting in no cerebral infarction. In another patient, intensive treatment was withdrawn because of massive brain swelling; however, slight but extensive early ischemic change was retrospectively confirmed on computed tomography prior to endovascular cooling. Vasospasm-related cerebral infarction occurred in one patient 2 days after removal of the cooling catheter. In one patient, fatal bacterial meningitis related to spinal drainage occurred on Day 29. Three-month outcomes showed good recovery in 2, moderate disability in 4, severe disability in 2, vegetative state in 1, and death in 2. Amelioration of fever burden during the first 14 days after onset of SAH was safe and feasible with combined surface and endovascular cooling in patients with WFNS Grade 5 SAH.

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Some reports have addressed the use of three-dimensional (3-D) models in simulated clipping of cerebral aneurysms. To report on the effectiveness of these models, for this study, we developed two types of 3-D models for use in clipping simulations and for clarifying angioarchitecture and surgical approaches.
The two types of model, one made of acrylic polymer and the other made of hollow silicone, were fabricated with a 3-D printer using data obtained with 3-D digital subtraction angiography (3D-DSA). The hollow silicone model was used for simulated clipping, whereas the acrylic model was used as a tool for clarifying angioarchitecture and surgical approaches. We performed simulated clipping of cerebral aneurysms with the two types of 3-D model for 10 patients with 11 cerebral aneurysms.
In 6 of the 11 aneurysms, the first clips accorded with the clipping simulations. The remaining 4 aneurysms exhibited only slight variation from the simulations. In 1 of the 11 aneurysms, the lengths and shapes of the first clips did not accord with the clipping simulations. The hollow silicone model was effective at aiding in the proper selection and manipulation of the clips. The acrylic model was effective at confirming the surgical approach, aneurysm depth, and backside angioarchitecture. Moreover, the procedures were performed smoothly with a microscope without the need to use the monitor, as it was utilized in a clean field.
These two types of 3-D model helped the surgeons gain a clear and intuitive understanding of aneurysm and angioarchitecture in three dimensions. As a result, they were highly useful for simulating clip application.

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Appropriate surgical treatment for partially thrombosed giant cerebral aneurysms compressing the brainstem remains unclear. Between 2011 and 2015, 4 patients with progressive neurological deterioration due to these complex lesions underwent direct neck clipping followed via intraaneurysmal thrombectomy in our institution. Postoperatively, the aneurysm size immediately decreased significantly, in association with early significant improvement in the surrounding brainstem edema. All patients showed neurological improvement after surgery. Our experience introduces this technique as a safe and more durable treatment option for the management of partially thrombosed giant cerebral aneurysms, especially in critical locations that require prompt decompression of vital structures.

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To identify the best surgical strategies, we analyzed our experience with distal posterior inferior cerebellar artery aneurysms (distal PICA AN) and reviewed the literature. We treated 6 patients with ruptured distal PICA ANs. The ANs were located at the anterior medullary segment (AMs: 2 cases), lateral medullary segment (LMs: 2 cases), televelotonsillar segment (TTs: 1 case), and cortical segment (Cs: 1 case). The AN at the Cs was a feeder aneurysm of a cerebellar arteriovenous malformation (AVM). All patients underwent direct surgery. Prior to surgery, 3 ANs were diagnosed as saccular type, and the remaining 3 were considered fusiform types, based on digital subtraction angiography or computed tomography angiography. However, one case of fusiform type appeared saccular during intraoperative observation. Neck clipping for saccular type ANs and trapping combined with occipital artery-PICA bypass for fusiform type ANs were successfully performed. Sparing of perforating branches adjacent to the ANs was attempted as much as possible during the trapping procedure. A transcondylar fossa approach was selected for the proximal segment (AMs, LMs) of the distal PICA ANs to decrease the risk of lower cranial nerve palsies. Standard lateral suboccipital craniotomy for a TTs AN and midline suboccipital craniotomy for a Cs AN were performed. All patients recovered favorably without ischemic complications or lower cranial nerve palsies. Preparation for revascularization with bypass, preservation of the perforators, and approaches using skull base techniques enable a good surgical result for distal PICA ANs.

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This is a case report of microsurgical removal of a ruptured intracranial infectious aneurysm with surrounding brain tissue based on the indocyanine green (ICG) videoangiography and histopathological evidence of adhesion between the aneurysm and brain. A 43-year-old man presented with sudden loss of consciousness and left hemiparesis. Computed tomography (CT) findings revealed an intraparenchymal hematoma in the right fronto-parietal lobe. Three dimensional CT angiography and digital subtraction angiography demonstrated a fusiform aneurysm of the distal middle cerebral artery (MCA) at the surface of the hematoma. Echocardiography revealed vegetation at the mitral valve, and he was diagnosed with infective endocarditis. The patient underwent superficial temporal artery (STA)-MCA anastomosis, excision of the aneurysm with surrounding brain tissue, and evacuation of the hematoma. Although the aneurysm could not be detected on the surface of the brain through microscopy, ICG videoangiography clearly revealed the aneurysm and the recipient artery, hidden by a thick subarachnoid hemorrhage and strong adhesions. ICG videoangiography was an effective procedure in this case. Histopathological findings demonstrated destruction of the aneurysmal wall structure and strong adhesions between the aneurysm and the brain tissue. These were consistent with the intraoperative findings.

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Introduction: Pediatric cerebral infarct is rare and sometimes difficult to diagnose and treat correctly. In this article, we report 4 cases of pediatric cerebral infarct caused by non-moyamoya disease, and discuss problems in the treatment and the specialties involved in care.
Case Presentation:〈Case 1〉 A 9-year-old girl developed left hemiparesis and was diagnosed with a cerebral infarct in the right internal capsule. She was treated with aspirin for 20 months without recurrence.
〈Case 2〉 A 13-year-old boy developed altered consciousness and was admitted to another hospital. Right carotid artery occlusion and stenosis of the left carotid artery and renal artery were diagnosed. He was treated with steroid and heparin for arteritis. At 3 days after onset, he was transferred to our hospital and underwent external decompression for cerebral infarcts in the right middle cerebral artery territory 5 days after onset. After cranioplasty, he was in status epilepticus and required barbiturate coma for 2 weeks. At 5 months after cranioplasty, he was transferred to the rehabilitation hospital for gait training.
〈Case 3〉 A 10-month-old girl developed left hemiparesis and was transferred to our hospital 3 days later. She was diagnosed with a cerebral infarct in the right putamen with agenesis of the carotid artery. She experienced cerebral infarcts twice and was finally diagnosed with embolic infarcts. She was treated with warfarin and aspirin for 12 months without recurrence.
〈Case 4〉 A 2-year-old girl with Klippel-Trenaunay syndrome had recurrent left hemiparesis and epilepsy. She was diagnosed with right carotid artery occlusion and was treated with aspirin for 12 months without recurrence.
Results: All 4 patients received medication and rehabilitation with subsequent functional recovery, although Case 2 underwent external decompression 5 days after onset. Team medical care involving the departments of Emergency Medicine, Pediatrics, Pediatric Neurology, and Neurological Surgery were needed for all patients. Mental health care was needed for both the patients and their patients.
Conclusion: There is no standard evidence-based treatment for pediatric cerebral infarct. The diagnosis and treatment are difficult. Individualized therapy is required because of unexpected complications. Team medicine involving multiple departments is needed for pediatric cerebral infarct.

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Carotid endarterectomy (CEA) is an effective stroke prevention strategy. However, carotid artery stenting (CAS) is widely performed as an alternative treatment because of its minimally invasive nature. Use of an embolic protection device (EPD) is essential during stenting to reduce surgical complications. Although these devices are designed such that they focus on the management of emboli traveling into the internal carotid artery, emboli traveling through the external carotid artery should also be considered, particularly in patients having severe arteriosclerosis with dangerous anastomosis. We report the case of a patient who developed postoperative cerebellar infarction following CAS for symptomatic stenosis. In this case, the patient demonstrated an anastomosis between the external carotid and vertebral artery that facilitated the transmission of emboli to the cerebellum. Collateral pathways and dangerous anastomosis must be considered prior to selecting surgical procedures.

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The interhemispheric approach after frontal craniotomy is a fundamental technique in microneurosurgery. However, it is quite difficult to employ without injuring the pia mater or pial capillary vessels, if the operator does not have precise and stable microsurgical technique. Itoh et al. described an interhemispheric approach in 1983 in which they recommended a 3-step procedure for the dissection of the interhemispheric approach. In the first step, the pericallosal cistern should be exposed; second, the arachnoid trabeculae between the cingulate gyrus and anterior part of the gyrus rectus should be dissected; and third, the bilateral residual gyrus rectus should be separated, exposing the aneurysm. A meticulous technique is required in the second and third steps to visualize the arachnoid trabeculae between the pia mater and vessels because of the compact microanatomical structures. The author describes technical suggestions for the effective use of microscissors and a cerebral retractor.

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