Anterior clinoidectomy (ACD) is an essential technique that is of utmost importance in direct surgery for paraclinoid aneurysm. ACD is usually performed using an extradural or intradural procedure. As for the choice between extradural and intradural clinoidectomy, 24 cases of paraclinoid internal carotid artery (IC) aneurysm were reviewed. These cases were categorized according to the Al-Rodhan classification. As a matter of principle, we chose extradural ACD for unruptured cases that require more decompression of the optic nerve and mobilization of the IC artery and intradural ACD for ruptured cases. Nine cases (ruptured, 1 case; un-ruptured, 8 cases) of group III aneurysm (carotid cave) and a relatively large unruptured case of group Ia aneurysm (superior hypophyseal), were treated with external ACD. In group III, ruptured in 1 case; group Ib (ventral paraclinoid), 4 cases (ruptured in 3 and unruptured in 1); group II (ophthalmic), unruptured in 1 case; group Ia, unruptured in 4 cases; and IC lateral (C2C3), unruptured in 2 cases, intradural ACD was performed. In a ruptured large case of group Ia, combined (extradural and intradural) ACD and multi-clipping using a suction and decompression method were performed. Aneurysm clipping was performed in all the cases except for 2 unruptured cases of wrapping after each ACD. Postoperative optic nerve injury occurred in 2 unruptured cases of group III. Each ACD was not thought to be a direct factor of postoperative optic nerve injury. Removal of the anterior clinoid process and optic unroofing, and circumferential dissection of the distal dural ring are key surgical procedures for ACD. The benefit of intradural ACD is the early exposure of the lesion and tailored anterior clinoid process resection. If an unintended event occurs during surgery, surgeons would be more able to control that event. The advantage of extradural ACD is minimal brain retraction. Extradural ACD will leave the dura intact until ACD is completed. Thus, the dura provides a natural protective barrier from neurovascular injury on drilling. Knowledge of the characteristics of each procedure is required in direct surgery for paraclinoid aneurysm. In conclusion, extradural ACD is appropriate for unruptured cases that require more decompression of the optic nerve and more mobilization of the IC artery, and intradural ACD is adequate for other unruptured cases. For ruptured cases, intradural ACD is safer than extradural ACD.

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Paraclinoid aneurysms can be defined as intracranial aneurysms arising from the internal carotid artery, between the distal dural ring and the posterior communicating artery. They include carotid-ophthalmic artery aneurysms, carotid-superior hypophyseal artery aneurysms, carotid cave aneurysms, etc. Paraclinoid aneurysms are considered as one of the most suitable lesions for endovascular treatment. However, surgical treatment is often necessary in cases with wide-neck and/or large aneurysms. When surgical clipping is performed for such aneurysms, the following skull-base techniques are considered in accordance with particular aneurysmal characteristics: extradural, intradural, and partial anterior clinoidectomy; opening the distal dural ring; and control of bleeding from the cavernous sinus. In the present report, we describe our experience with and the clinical outcome of paraclinoid aneurysms treated surgically. Twenty-three consecutive patients who underwent surgical neck clipping between January 1, 2010 and March 31, 2016, were included in this study. Three out of 23 patients presented with subarachnoid hemorrhage, and four had visual disturbances. The aneurysms of 16 patients were identified incidentally. Complete exclusion was confirmed in all patients on follow-up angiography. New visual complications were not detected in patients who had no preoperative ophthalmological symptoms. On the other hand, out of the four patients who had visual disturbances before surgery, one experienced improved symptoms, two indicated no change, while the visual acuity of one patient deteriorated to blindness. The present study shows that surgical clipping is still one of the therapeutic options in most cases of paraclinoid aneurysms. Basic skull base technique is an indispensable factor for successful clinical results.

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The risk of complications is reportedly high after surgical clipping of aneurysms (ANs) in the middle cerebral artery (MCA-AN), on the medial side of the limen insulae. These are classified as M1 segment aneurysms or short M1 aneurysms. We named these aneurysms medial insulae MCA-ANs and classified them into four types as follows: 1) lenticulostriate artery (LSA) M1 ANs, 2) cortical M1 ANs, 3) short M1 ANs, and 4) anterior temporal artery (ATA) M1 ANs. Subsequently, we analyzed the surgical outcomes for each type. We had 21 cases of medial insulae MCA-ANs (including 5 ruptured cases) treated with surgical clipping and monitoring using motor-evoked potential (MEP) and indocyanine green video-angiography (ICG-VAG). Of the patients, 8 were men and 13 were women. Their mean age was 66 years (range, 35-83 years). The mean aneurysm size was 5.5 ± 2.2 mm. Of the cases, 3 (14.3%) were LSA M1 ANs; 6 (28.6%), cortical M1 ANs; 10 (47.6%), short M1 ANs; and 2 (9.5%), ATA M1 ANs. Two patients had surgical ischemic complications from the perforating arteries. One had a case of short M1 AN with an asymptomatic left striatum infarction, while the other had a case of cortical M1 AN with postoperative transient paralysis, although the intraoperative MEP decreased. No permanent neurological deficit remained. Medial insulae MCA-ANs are considered hemiparetic complications. Thus, surgeons must accurately judge the type of aneurysm and understand the relationship between the neck and the perforators before clipping.

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The options for treating unruptured aneurysms in elderly patients have increased, and are discussed herein. We statistically analyzed the outcomes of 69 unruptured aneurysms in patients aged under 75 and over 76 years old treated between October 2013 and March 2016. Treatment in those under 75 years old resulted in modified Rankin Scale (mRS) scores of 0-1. In contrast, treatment in those over 76 years old resulted in mRS scores of 4 in 1 patient with a cerebral infarction and 1 with a cerebral hemorrhage (40%, 2/5) (p<0.05). An aneurysm in a 79-year-old was treated with refuge embolization, and she is now well. We conclude that unruptured aneurysms in patients over 76 years old should be managed carefully. If necessary, refuge coil embolization is an option.

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Background: Aneurysms less than 5 mm in diameter (small aneurysms) are generally believed to have a low rupture rate. In our clinical experience, they are often found ruptured, causing subarachnoid hemorrhage (SAH). Herein, we report our investigation on the characteristics, severity, and prognosis of cases of ruptured small aneurysm.
Patients and Methods: We reviewed the data of 158 consecutive patients with aneurysmal SAH (except for those with dissecting aneurysms) treated in our hospital between 2009 and 2014. The maximum size, configuration, location, and distribution of aneurysms were examined using computed tomography angiography or digital subtraction angiography. We chose the following 7 risk factors for rupture to examine 53 cases of small ruptured aneurysms: age (< 50 years old), aneurysm with daughter sac, past medical history of hypertension, multiple aneurysms, family history of SAH, smoking habits, and excessive alcohol intake. In addition, we compared these 53 cases to the rest of the group with regard to symptoms (Hunt and Hess grade [H&H]), amount of hemorrhage (modified Fisher grade [mFisher]), prognosis (modified Rankin Scale [mRS]), and number of risk factors.
Results: Of the 158 cases of ruptured aneurysms, 49 involved the anterior communicating artery (Acom), 41 involved the middle cerebral artery (MCA), 29 involved the internal carotid-posterior communicating artery (IP-PC), and 39 involved other locations. The average maximum diameter was 6.6 mm (range: 1.2-30 mm). Among the 53 small aneurysm cases (34% of the total), 33% were located in the Acom, 28% in the IC-PC, and 17% in the MCA. In low sites with infrequent aneurysms such as the internal carotid-anterior choroidal artery (IC-ACh) or the basilar top artery (BA top), small aneurysms accounted for more than 50%. After analysis of the risk factors for the 53 small aneurysm cases, 4 patients (8%) had no risk factors. There was no statistically significant difference between H&H grade, mFisher grade, mRS, and the number of risk factors between the groups with small aneurysms and aneurysms 5 mm or larger.
Conclusion: Cases with ruptured small aneurysms (<5 mm in diameter) accounted for approximately one-third of aneurysmal SAH cases in our institution. Many ruptured small aneurysms were located in the Acom or IC-PC. Four patients (8%) with ruptured small aneurysms had no risk factors. Further study is needed to identify the characteristics of ruptured small aneurysms.

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A 33-year-old man presented with subarachnoid hemorrhage (Hunt and Kosnik grade II, World Federation of Neurological Surgeons [WFNS] grade I, Fisher group 3). Cerebral angiography revealed two anterior choroidal arteries and an aneurysm in a distal branch, in addition to an occlusion at the beginning of the right middle cerebral artery (MCA) and ipsilateral moyamoya vessels (unilateral moyamoya disease). On day 5, proximal ligation and bypass (superficial temporal artery [STA]-MCA anastomosis and encephalo-myo-synangiosis [EMS]) was performed. After surgery, neither symptomatic cerebral vasospasm nor hydrocephalus occurred. The patient was discharged without any neurological deficits. According to several reports, in cases of ruptured aneurysms associated with main trunk artery occlusion, it is important to operate both the aneurysm and STA-MCA anastomosis simultaneously in the acute phase to prevent re-rupture of the aneurysm and improve the cerebral blood flow. Thus, combination surgery consisting of proximal ligation and direct/indirect bypass in the acute phase is considered useful for hemorrhagic moyamoya disease.

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We report a case of an unruptured true posterior inferior cerebellar artery (PICA) aneurysm forming kissing aneurysms with a ruptured vertebral artery-posterior inferior cerebellar artery (VA-PICA) aneurysm in a 49-year-old woman that was successfully treated with direct surgery. Left vertebral angiogram revealed a VA-PICA aneurysm and an adjacent small bulge in the PICA. Intraoperatively, these two aneurysms adhered tightly to one another, necessitating complete dissection and clipping of both aneurysms. This is the first case of kissing aneurysms at the VA-PICA junction to be reported. It is important to remember that we may encounter kissing aneurysms of VA-PICA and PICA. As in the present case, preoperative diagnosis may be difficult.

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Objective: We designed a direct road map method during carotid artery stenting (CAS) in March 2015. We evaluated the effectiveness of this method for 13 lesions in 12 patients who underwent CAS between March 2015 and May 2015. Patient ages ranged from 54 to 97 years (average: 74.9 years). Ten patients were male, and 7 lesions were symptomatic.
Methods: The Mo.Ma Ultra (Mo.Ma) is used as an introducing catheter. Both balloons of the Mo.Ma (the distal balloon in the external carotid and the proximal balloon in the common carotid), are inflated and a tolerance test is performed. If the tolerance test is negative, a PercuSurge GuardWire (PSGW) is advanced to the internal carotid artery (ICA) as a distal embolic protection device. Contrast medium is slowly injected from the Mo.Ma, and the ICA is filled with contrast medium. The PSGW is inflated during this injection, and contrast medium is trapped in the ICA. CAS is performed with reference to the trapped contrast medium.
Results: Mo.Ma could be advanced to the target vessel in 8 lesions. One case did not tolerate ICA occlusion and a filter device was substituted. Combined use of Mo.Ma and PSGW was performed in the remaining 7 lesions. Direct road mapping was clinically useful in 5 lesions.
Discussion: The image in conventional road mapping is sometimes tilted with straightening of the vessel. This phenomenon occasionally occurs during stent deployment. Direct road mapping solves this problem.
Conclusions: Direct road map using Mo.Ma and PSGW is useful during CAS.

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Background: Internal carotid artery stenosis (ICS) is relatively common in elderly people and is a major cause of disabling stroke. We examined surgical treatment and clinical features in elderly patients with ICS.
Methods: A total of 157 consecutive patients with ICS and a mean age of 73.3 years were enrolled at Kyushu Rosa Hospital between 2013 and 2015, and 3-month follow-up was performed to assess postoperative outcomes.
Results: Of 57 surgically treated patients (mean age 73.1 years), 52 underwent carotid endarterectomy (CEA) and 5 underwent carotid artery stenting (CAS). Of these, 47 patients were symptomatic and 10 were asymptomatic. All 15 patients older than 80 years underwent CEA for unstable plaques. The morbidity rate at 3 months was 3.5% (2 patients aged >80 years who underwent CEA).
Conclusion: CEA achieves acceptable outcomes regarding stroke prevention in elderly patients, but appropriate perioperative management is mandatory.

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Introduction: Monitoring for intra-operative patency of the extracranial (EC)-M2 bypass is important to avoid ischemic complications. Tools such as ultrasound micro-flow probe and indocyanine green videoangiography are commonly used for EC-M2 monitoring. Middle cerebral artery pressure (MCAP) monitoring is another tool to assess the patency of the EC-intracranial (IC) bypass. We retrospectively analyze and discuss a series of cases of EC-M2 bypass with MCAP monitoring.
Methods: We performed EC-M2 bypass with MCAP monitoring in 84 patients at our institution. Before EC-M2 bypass, we performed superficial temporal artery (STA)-MCA bypass, and MCAP was measured through another branch of the STA.
Initial MCAP (iMCAP), MCAP after clamping of the ICA (cMCAP), and MCAP after releasing the graft (actual gMCAP) were intraoperatively monitored. The MCAP ratio was defined as gMCAP/iMCAP. On the basis of the Hagen-Poiseuille's law, the expected MCAP ratio (expected gMCAP/iMCAP) was hypothesized as: (1－cMCAP/iMCAP)(graft radius/ICA radius)² + cMCAP/iMCAP. Graft malfunction was defined as a discrepancy between the expected gMCAP and actual gMCAP.
Results: Eight of 84 cases were judged to have graft malfunction by MCAP monitoring and had to be re-anastomosed.
The cause of graft malfunction was twisting of the graft in one case, insufficient graft length in 2 cases, severe atherosclerosis of the external carotid artery in 3 cases, M2 proximal twisting owing to pressure of the EC-M2 bypass in one case, and kinking due to an elongated styloid process in one case. After re-anastomosis, the MCAP in 7 cases improved, whereas in 1 case, acute graft occlusion after operation was seen.
Conclusions: MCA pressure monitoring, combined with other monitoring tools, is effective for assessing graft malfunction during surgery and can help achieve favorable patency of the EC-M2 bypass.

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Objective: Vertebral arteriovenous fistulas (VAVFs) are uncommon lesions and are caused by traumatic or spontaneous origin. Tinnitus or bruit is the most common symptom of VAVFs, but there are no reported cases that weight loss is a chief complaint.
Case presentation: A 26-year-old man presented with weight loss and a supraclavicular pulsatile mass. Seven years prior to this admission, his right jugular vein had been catheterized for treatment of Guillain-Barré syndrome. Digital subtraction angiography showed a high-flow VAVF between segment V1 of the right vertebral artery and the paravertebral venous plexus. The fistula was successfully trapped internally by using detachable coils. The postprocedural course was good, and there has been no recurrence during the 31 months of follow-up. The body weight of the patient recovered by 10 kg in the year after treatment. It is considered that the mechanisms of the weight loss in VAVF are similar to the mechanisms of the weight loss which is one of the complications in the cases of heart failure.
Conclusion: Endovascular treatment may be considered the treatment of choice for VAVFs.

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