Objective: We performed a percutaneous carotid artery stenting (CAS) under ultrasono-graphic (US) guidance without contrast in patients with impaired renal function. We present the CAS procedure, which avoids the simultaneous use of fluoroscopy and US examination, to reduce radiation exposure.

Methods: The carotid-stenotic lesion was marked on the skin of the neck based on preoperative US images. The distal protection balloon (DPB) was placed beyond the stenotic portion under fluoroscopy using magnetic resonance angiography and/or plain computed tomography images. The location of the DPB was confirmed by fluoroscopy. Subsequently, the DPB was expanded, and the carotid ultraso-nography confirmed that blood flow was restricted. Thereafter, a stent was placed on the stenotic portion, and the dilatation of the artery was also confirmed by US imaging.

Results: Among the six patients (mean age: 78.8 years) included in this study, three asymptomatic and three symptomatic cases were successfully treated using the US-guided CAS technique without complications. The operation time of this technique was similar to that of the conventional method. The average cumulative incident dose (CID) was 64.0 mGy (average CID value of the standard method: 162.4 mGy).

Conclusion: Percutaneous US-guided carotid stenting is useful for patients with carotid stenosis and impaired renal function. Avoiding the simultaneous use of fluoroscopy and ultrasonography can reduce radiation exposure for both technicians and patients.

Background: Appropriate preoperative patient evaluation and careful perioperative management are important to perform carotid artery stenting (CAS) safely. We aimed to investigate the usefulness of a preoperative checklist and a procedural routine.

Method: We evaluated patients who had undergone CAS at our hospital between April 2011 and March 2018. A preoperative checklist and procedural routine have been used since October 2014. The patients were divided into a non-checklist group and a checklist group. The clinical characteristics were statistically compared between the two groups.

Result: The non-checklist and checklist groups included 61 (mean age, 74 ± 9 years; 82% male) and 52 patients (mean age, 74 ± 8 years; 83% male), respectively. Comorbidities, hyperlipidemia, and diabetes mellitus occurred significantly more frequently in the checklist group than in the non-checklist group (p ＜ 0.01 and p = 0.03, respectively). Other comorbidities were similarly observed in both groups. Perioperative complications within 30 days after CAS occurred significantly less frequently in the checklist group (11% of the non-checklist group vs. none of the checklist group, p = 0.015).

Conclusion: Using the preoperative checklist for CAS and applying its procedural routine may improve treatment outcomes and result in fewer perioperative complications within 30 days after the procedure.

Purpose: Early diagnosis of cerebral vasospasm is a key factor for therapeutic management of cerebral vasospasm after subarachnoid hemorrhage (SAH). However, a noninvasive method of diagnosing delayed ischemic neurological deficit (DIND) has not been established. Therefore, we propose a new method of diagnosing cerebral ischemia by detecting changes in cerebral oxygenation using near infrared optical topography (OT) with oxygen inhalation.

Materials and Methods: We used a 44-channel OT system covering the bilateral fronto-temporo-parietal areas to assess 29 patients who underwent surgery within 72 h from the onset of SAH. The patients inhaled room air followed by oxygen for 2 min, after which peripheral oxygen saturation (SpO₂) at the index fingertip was continuously monitored. The patients were assessed using I-123 iodoamphetamine single photon emission computed tomography (IMP-SPECT) and OT on the same day. Ischemic findings were confirmed using principal component analysis with reference to the systemic SpO₂ value.

Results: Seven out of 29 patients developed DIND. Evidence of ischemia was identified by OT in all seven patients before the onset of DIND. The OT findings were consistent with SPECT findings in 26 (89.7%) of the 29 patients. Enhanced treatment of vasospasm improved ischemia in 65% of patients in whom early ischemic findings had been detected by OT, and consequently, DIND did not develop. After arterial fasudil injection, OT detected an improvement in ischemic findings.

Discussion and Conclusions: Our method might help in early detection of cerebral ischemia before the onset of DIND and, thus, be clinically useful in the assessment of cerebral ischemia with vasospasm and in the perioperative therapeutic management of cerebral vasospasm.

With the introduction of the diagnosis procedure combination (DPC) in Japan, it has become possible to study precise disease data. In this study, we analyzed the current state of subarachnoid hemorrhage (SAH) using the DPC data.

From the Ministry of Health, Labor, and Welfare website, we accessed the DPC evaluation subcommittee in the Central Social Insurance Medical Council. We examined the current treatment state of SAH using its aggregation from the MDC01 database for each diagnostic group classification from fiscal year (FY) 2012 to FY 2015.

From FY 2012 to FY 2015, the DPC data were obtained from 1,774, 1,804, 2,942, and 3,191 hospitals, respectively, and 17,131, 17,627, 18,468, and 17,246 patients with SAH discharged, respectively. Although the number of conservative and clipping treatments decreased from FY 2012 to FY 2015, the number of coiling and drainage treatments slightly increased. The proportion of clipping treatment for all surgical treatments declined from 70.3% to 63.5% during this period. The proportion of elderly people (≥ 80 years) increased from 14.3% to 18.0% between FY 2012 and FY 2015, and the mortality rate at discharge was similar between FY 2012 (18.9%) and FY 2015 (19.9%).

In FY 2015, of the 17,246 cases of SAH, the mild condition group had 8,976 (52.0%) cases (JCS < 10), while the severe group (JCS ≥ 10) had 8,270 (48.0%) cases. The conservative treatment, other operations, coiling, drainage, and clipping treatments were performed for 4,972 (29%), 331 (2%), 1,922 (11%), 2,439 (14%), and 7,582 cases (44%), respectively, and the proportion of severe cases was 42.5%, 53.2%, 37.9%, 63.4%, and 48.9%, respectively. In the severe group, the proportion of elderly people with conservative treatment was 42.4% and was highest in all treatments. At discharge, the mortality rate was 38.2% with conservative treatments and particularly high in the severe group (82.0%). On the contrary, the mortality rate at discharge in clipping treatment was 10.0% which was lowest among all treatments.

The analysis of the DPC data clarified the current state of SAH treatment in Japan. The DPC data may be an essential tool for monitoring disease trends.

Although stent-assisted embolization is useful for wide-neck aneurysms, this technique is not permitted for acutely ruptured aneurysms in Japan. Consequently, the treatment of choice tends to be staged embolization, in which partial embolization without a stent and stent-assisted tight embolization are used for first and second stages, respectively. Recently, we encountered a case of acutely ruptured aneurysm in which the patient had a very wide neck and partial embolization without a stent was impossible. Instead, we performed stent-assisted embolization; moreover, this procedure was performed in three other cases thereafter. All of the patients presented with acutely ruptured internal carotid artery aneurysms and had very wide necks. Although balloon-assisted embolization was attempted, this approach failed in all cases. Stent-assisted embolization was then performed following rapid clopidogrel loading. We tightly packed the rupture point while loosely packing the portion at the neck. Neuroform EZ® and Atlas® stents were used in one and three cases, respectively. The rupture point was cleared immediately after embolization in all cases, and no rerupture was observed. There was one instance of thrombotic complication due to protrusion of the coil. Additional embolization was required in two cases more than six months later. In conclusion, stent-assisted embolization should be performed for acutely ruptured aneurysms if the use of other methods is not possible.

The treatment outcomes of unruptured cerebral aneurysms (UA) have improved due to a combination of open surgery and endovascular surgery. However, it remains unclear which patients should be screened for UAs. Thus, we clarified the risk factors associated with the detection of UAs to be treated. Five hundred and sixty-six patients examined by brain dock and 35 patients treated for UAs were included in this study. Results: The UAs detected by brain dock were 14 (2.4%). Hypertension, hyperlipidemia, history of cerebrovascular disease, and headache were risk factors for UAs that reuire treatment. In conclusion, for detecting UAs that should be treated, brain screening for patients with hypertension, hyperlipidemia, history of cerebrovascular disease, and headache is important.

Background and Purpose: The natural history and therapeutic management of patients with unruptured vertebral dissections presenting with headache remains unclear. We retrospectively assessed 41 consecutive patients treated for unruptured vertebral dissections that presented with headaches.

Methods: We identified 41 patients diagnosed with vertebral artery dissection through magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), and angiography between April 2008 to March 2017 and who experienced only headache at the time of onset. All patients underwent MRI, MRA, or three-dimensional computed tomography (CT) every 1-4 weeks for 3 months, every 1-3 months between 3 and 6 months, every 3-6 months 6 months post-onset, or more often depending on the situation. Clinical characteristics, morphological changes, and treatments were analyzed.

Results: Headaches were posteriorly located in 39 cases, however, there were no specific findings other than location. Primary radiographic investigations showed dilatation in 13 cases, pearl and string signs in 20 cases, and stenosis or occlusion in 8 cases. Following the initial conservative treatment, morphologic changes were improved in 27 cases, dilated and occluded in 8 cases, and remained unchanged in 6 cases. The most morphological changes were seen within 3 months for 35 cases, with a mean time of 1.6 months, however, for 6 cases the mean time was 11.2 months. These 6 patients showed dilation and occlusion as morphological changes. Five of these 6 patients' dissection sites enlarged and 3 underwent surgical treatment at a mean of 7.7 months post-onset. The remaining 2 patients were treated conservatively; their dissection sites healed and decreased. None of the patients experienced bleeding or neurological deficits during follow-up.

Conclusion: Clinicians should monitor patients with unruptured vertebral dissections who present with headache to prevent stroke development. It should be noted that even if the dissection site enlarges without new symptoms, acute intervention is not always required and patients should be treated with careful radiographic follow-up.

Thrombectomy is currently recommended for eligible patients with acute stroke who are treated within 6 hours of onset. However, wake-up stroke or stroke with an unclear onset of symptoms is known to occur in approximately 25% of all patients diagnosed with ischemic stroke. Acute stroke with unknown time of onset or onset more than 6 hours prior to detection is not considered for thrombectomy because the effectiveness is uncertain. However, recent trials of endovascular treatment for acute ischemic stroke more than 6 hours after onset have been successful due to the use of accurate perfusion imaging of the penumbral region of tissue, calculated using an automated image post-processing system. In this study, we determined the efficacy and safety of endovascular treatment in patients with acute ischemic stroke onset of more than 6 hours, in whom the indications for thrombectomy had been determined by the mismatch between diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR).

We reviewed the clinical records of 29 consecutive patients who underwent thrombectomy for acute ischemic stroke between January 2016 and December 2017. Of the 29 patients, 9 had presented more than 6 hours after stroke onset, and 20 had presented within 6 hours. The indication for thrombectomy was decided using DWI-FLAIR mismatch, which was defined as a new hyperintense lesion on DWI without any hyperintense signal change on FLAIR. The rates of favorable outcome and mortality at discharge, recanalization rate, and symptomatic intracranial hemorrhage did not differ significantly between the two groups.

In conclusion, with the use of DWI-FLAIR mismatch, thrombectomy for acute strokes detected more than 6 hours after onset appears to be as safe and efficient as thrombectomy for strokes detected within 6 hours of onset.

Objective: To examine whether antithrombotic therapy affects the incidence of postoperative hemorrhage after endoscopic hematoma removal for hypertensive intracerebral hemorrhage (ICH), and whether prothrombin complex concentrate (PCC) is useful in reducing adverse events.

Methods: We retrospectively reviewed 193 patients who underwent endoscopic hematoma removal for ICH between January 2004 and July 2018. Patients with vascular abnormalities, including moyamoya disease and arteriovenous malformation were excluded. Contributing clinical factors of postoperative hemorrhage were analyzed, and the effectiveness of the preoperative use of PCC for patients receiving anticoagulants was evaluated.

Results: Among the 193 patients, 35 were taking antithrombotic agents (18%), including 19 on anticoagulants (warfarin=14, direct oral anticoagulants=5) and 21 taking antiplatelet agents. Postoperatively, 13 patients (6.7%) showed hemorrhage at the surgical site, which was associated with worse clinical outcome. Among the clinical factors analyzed, only anticoagulants showed a statistically significant relationship to postoperative hemorrhage. The effect of antiplatelet agents was not significant. For patients receiving warfarin, vitamin K2 was routinely administered before surgery, and as of 2012, PCC was additionally administered to 9 patients. After the introduction of PCC, no further patients on anticoagulants experienced postoperative hemorrhage.

Conclusion: Patients receiving anticoagulants are at higher risk of postoperative hemorrhage after endoscopic intracerebral hematoma removal, however, the preoperative use of PCC effectively prevented postoperative hemorrhage.

Objective: We aimed to investigate whether it is necessary to interrupt antithrombotic drug administration at the time of cranioplasty after decompressive craniectomy for cerebral infarction.

Methods: We retrospectively examined 18 patients who underwent cranioplasty for cerebral infarction due to main trunk occlusion at our hospital between December 2008 and December 2016.

Results: The mean age of the patients was 68.8 years, with 14 men. Regarding the administration of antithrombotic drugs as maintenance therapy for cerebral infarction, 2 patients were given antiplatelet drugs, while 13 patients were given anticoagulant drugs. Owing to their general condition, 3 patients received no antithrombotic drugs. After cranioplasty, we interrupted the administration of antithrombotic drugs in 11 patients. These patients in addition to the 3 patients who were not given antithrombotic drugs were referred to as the interruption group. Heparin was given to 3 patients who we collectively referred to as the heparin group. Lastly, the administration group was composed of 4 patients who continued to take antithrombotic drugs. After cranioplasty, a total of 13 patients experienced either subcutaneous or epidural hematomas. Among them, 55% were in the interrupted group, while the remaining 45% of cases occurred in all of the patients in the heparin and administration groups. However, none of the hematomas needed to be removed.

Conclusion: Both antiplatelet drug administration and the replacement of anticoagulants with heparin can be considered prior to major surgery (Japanese Guidelines for the Management of Stroke 2015, grade C1). However, the worsening of symptoms due to interruptions in antithrombotic drug administration must also be considered. Nonetheless, hemostasis is easily achieved at the time of cranioplasty, and continued antithrombotic drug use is unlikely to result in bleeding requiring reoperation. While the prevailing guidelines regarding the interruption of medications should be adhered to, the respective risks of hemorrhagic and ischemic complications must be carefully considered.

Superficial temporal artery to middle cerebral artery (STA-MCA) bypass is an essential technique, not just for treating cerebral ischemia but also for assisting aneurysm clipping and compensating for unexpected vascular injuries during surgery.

Although it is becoming a more fundamental surgery technique because of the provision of off-the-job training, there are several points that should be considered to achieve successful anastomosis. In this article, we describe important points and tips to consider during STA-MCA bypass.

To perform a successful anastomosis, it is important to ensure the following: (1) creation of an operative view without blood and cerebrospinal fluid, (2) selection of a suitable recipient artery, and (3) prevention of anastomosis occlusion.

A recipient artery that runs downward from right to left (when the operator is right-handed) is considered suitable because of easier needle handling while suturing. Suturing the backside and inversion of the anastomosis should be avoided to prevent anastomosis occlusion. To avoid suturing the backside, we perform an oval arteriotomy on the recipient artery instead of a linear incision. Furthermore, difficult anastomosis is prioritized, and stay sutures and bilateral sutures are performed by the marked pin method and T-junction bypass when anastomosing in part with a large-diameter branch. To avoid inversion, we require the stitch interval of the donor and recipient arteries to be at a ratio of 6:4. We also tie a knot by pulling the thread from the donor side, which ensures that the inner membranes are attached together.

Anastomosis is the most important procedure because the ultimate goal of this operation is to prevent cerebral ischemia by achieving long-term patency. The technique should be unified and simplified so that it is available for even young neurosurgeons.

The techniques we have introduced are not difficult or complicated, although they can only be put into practice after acquiring the basic skills. Therefore, young neurosurgeons must continue training and preparing for surgeries.