Efficacy and Safety of Lumbar Drainage before Endovascular Treatment for Ruptured Intracranial Aneurysms

Objective

Intraoperative rebleeding during endovascular treatment for ruptured intracranial aneurysms is associated with poor prognosis. Lumbar drainage is performed preoperatively to control intracranial pressure; however, it is associated with a risk of brain herniation or rebleeding because intracranial pressure may change rapidly. Therefore, this study aimed to examine the efficacy and safety of preoperative lumbar drainage.

Methods

This retrospective study enrolled 375 patients who underwent endovascular treatment of ruptured intracranial aneurysms at our institution between April 2013 and March 2018. The incidence of rebleeding and clinical outcomes were compared between patients who did and did not undergo preoperative lumbar drainage.

Results

Among the 375 patients with ruptured intracranial aneurysms, 324 (86.0%) and 51 (14.0%) patients did and did not undergo lumbar drainage, respectively. The incidence of rebleeding was 11/324 (3.4%) and 2/51 (3.9%) in lumbar drainage and nonlumbar drainage groups, respectively, with no statistical differences (p = 0.98). Of the rebleeding cases, 9/11 (81%) and 2/2 (100%) in lumbar drainage and nonlumbar drainage groups, respectively, were due to intraoperative bleeding, and 2/11 (19%) in the lumbar drainage group, the causes of the rebleeding were undetermined. The incidence of symptomatic vasospasm did not differ significantly between the groups (13.2% vs. 11.8%, P = 0.776), while the incidence of hydrocephalus (24.6% vs. 11.8%, P = 0.043) and meningitis (15.2% vs. 5.9%, P = 0.075) were slightly higher in the lumbar drainage group. Favorable clinical outcomes (modified Rankin Scale score <2) at discharge were less frequent in the lumbar drainage group (55.3% vs. 70.0%, P = 0.051). No significant differences were observed in the propensity score-matched analysis.

Conclusion

Lumbar drainage before endovascular treatment for ruptured intracranial aneurysms is a safe procedure that does not increase the incidence of rebleeding.

Aneurysm Isolation is Associated with Complete Occlusion of Aneurysms After Flow Diverter Treatment

PURPOSE

Some aneurysms remain patent after treatment with flow diverters (FD) due to residual blood flow in the aneurysm. Several studies have proposed that branches and residual flow are associated with delayed aneurysm occlusion. We propose that aneurysm isolation (i.e., the complete disconnection of the aneurysm from surrounding vessels) might be a possible factor facilitating aneurysm occlusion. This study aimed to determine if aneurysm isolation was a factor associated with aneurysm occlusion after FD treatment.

METHODS

We reviewed 80 internal carotid artery (ICA) aneurysms treated with FDs between October 2014 and April 2021. Aneurysm isolation was assessed in high-resolution cone-beam computed tomograms at the end of each treatment. Aneurysms with incorporated branches and those with connections to other branches due to stent malapposition were deemed to be nonisolated. Other factors, such as patient age, sex, anticoagulant use, aneurysm size, adjunct coil use, and the presence of incorporated branches, were considered. The degree of aneurysm occlusion (complete or incomplete) was assessed by follow-up angiograms 12 months after treatment.

RESULTS

Complete occlusion was achieved in 57 of 80 aneurysms (71%). Completely occluded aneurysms had a significantly higher ratio of isolation compared to incompletely occluded aneurysms (91.2% vs. 69.6%, P = 0.032). Multivariate logistic regression analysis showed that aneurysm isolation was the sole significant predictor of complete aneurysm occlusion (odds ratio, OR 19.38; 95% confidence interval, CI 2.280-164.657; P = 0.007).

CONCLUSION

Aneurysm isolation is a significant factor contributing to complete occlusion after FD treatment.

The impact of SAH finding on CT to the clinical outcome after mechanical thrombectomy for large vessel occlusion

BACKGROUND AND PURPOSE

Whether subarachnoid haemorrhage (SAH) after mechanical thrombectomy affects the clinical outcomes of patients with acute large-vessel occlusion remains unclear. This study aimed to investigate the clinical impact of SAH on computed tomography (CT) after mechanical thrombectomy.

METHODS

The SKIP study was an investigator-initiated, multicentre, randomised, open-label clinical trial. This study was performed in 23 hospital networks in Japan from January 1, 2017, to July 31, 2019. Among the 204 patients, seven were excluded because they did not undergo mechanical thrombectomy (MT) and had a modified Rankin scale (mRS) score > 2. The main outcome was the association between SAH within 36 h after mechanical thrombectomy and the clinical outcome at 90 days.

RESULTS

Among 197 patients, the median age was 74 (67-79) years, 62.9% were male. Moreover, 26 (13.2%) patients had SAH (seven isolated SAH) on CT within 36 h. The SAH rate did not differ according to IV rt-PA administration (p = 0.4). The rate of favourable clinical outcomes tended to be lower in patients with SAH rather than patients without SAH (11 [42%] vs. 106 [62%], p = 0.08). Among the seven patients with isolated SAH, 6 showed favourable outcomes at 90 days. In the multivariate regression analysis, the presence of SAH within 36 h from onset was not associated with clinical outcome (Odd ratio, 0.59; 95% confidence interval, 0.18-1.95; p = 0.38).

CONCLUSIONS

Among patients with acute stroke treated with MT, SAH, especially isolated SAH findings on CT, were not associated with poor clinical outcomes after 90 days.

TRIAL REGISTRATION NUMBER

UMIN000021488.

Ultra-early rt-PA administration should improve patient outcome on mechanical thrombectomy: Post hoc analysis of SKIP

BACKGROUND

To investigate whether ultra-early recombinant tissue-plasminogen activator (rt-PA) administration can improve patient outcomes on mechanical thrombectomy (MT) in patients with large vessel occlusion (LVO).

METHODS

Participants comprised rt-PA-eligible 204 patients with internal carotid artery or middle cerebral artery occlusion in the SKIP trial, who were randomly assigned to receive mechanical thrombectomy alone or combined intravenous thrombolysis (rt-PA: alteplase at 0.6 mg/kg) plus mechanical thrombectomy. We assessed associations between onset-to-puncture time and onset-to-rt-PA administration time and frequency of favorable outcome at 90 days and any intracerebral hemorrhage (ICH) at 36 h after onset.

RESULTS

As a cut-off onset-to-puncture time for favorable outcome, receiver operating characteristic curves defined 2.5 h (57% sensitivity, 62% specificity). For onset-to-puncture times ≤2.5 h and > 2.5 h, frequencies of favorable outcomes were 72% and 63% (p = 0.402) in patients with rt-PA therapy and 44% and 58% (p = 0.212) in patients without rt-PA therapy, respectively. In terms of onset-to-rt-PA administration time, frequencies of favorable outcomes among patients with ultra-early rt-PA administration at ≤100, >100 min after onset, and without rt-PA therapy with onset-to-puncture time ≤ 2.5 h, and with and without rt-PA therapy with onset-to-puncture time > 2.5 h were 84% and 64%, 63%, and 44% and 58%, respectively (p = 0.025). Frequencies of any ICH among those patients were 37% and 32%, 32%, and 63% and 40%, respectively (p = 0.006).

CONCLUSION

Ultra-early rt-PA administration should improve patient outcomes on mechanical thrombectomy among patients with LVO. Relatively late rt-PA administration might increase the frequency of any ICH.

Comparison of the Clinical Outcome of Carotid Artery Stenting Between Institutions With a Treatment Strategy Based on Risk Factors and Those With First-Line Treatment

PURPOSE

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are recommended based on certain risk factors. The volume of an institution's treatment experience may be associated with good clinical outcomes. There is a dilemma between the treatment strategy based on risk factors and the experience volume. Therefore, we investigated the clinical outcomes of CAS performed at institutions that selected the treatment strategy based on risk factors and those that performed CAS at the first-line treatment.

MATERIALS AND METHODS

Patients who underwent CAS at 5 institutions were included in this retrospective case-control study. We defined CEA/CAS institutions as those that selected the treatment option based on risk factors, and CAS-first institutions as those that performed CAS as the first-line treatment. We investigated cases of ischemic stroke, hemorrhagic stroke, myocardial infarction, and deaths within 30 days of the intervention between the CEA/CAS- and CAS-first institution groups. One-to-one propensity score matching was performed to compare rates of ischemic and hemorrhagic strokes within 30 days of the intervention.

RESULTS

A total of 239 and 302 patients underwent CAS at the CEA/CAS institutions and CAS-first institutions, respectively; ischemic stroke occurred in 12 (5.0%) and 7 patients (2.3%), respectively (p=0.09). No differences in major ischemic strokes (0.8% vs 1.3%; p=0.59), hemorrhagic strokes (0.4% vs 0.3%; p=0.87), or deaths (0.0% vs 0.7%; p=0.21) were observed. Myocardial infarction did not occur in either group. Propensity score analysis showed that ischemic stroke (odds ratio: 1.845, 95% confidence interval: 0.601-5.668, p=0.28) and hemorrhagic stroke (odds ratio: 1.000, 95% confidence interval: 0.0061-16.418, p=1.00) were not significantly associated with either institution group.

CONCLUSIONS

The CAS-specific treatment strategies for CAS can achieve the same level of outcomes as the treatment strategy based on risk factors. The CAS performed based on risk factors in CEA/CAS institutions and the treatment of more than 30 patients/year/institution in CAS-first institutions were associated with good clinical outcomes.

Image Quality and Radiation Dose of Conventional and Wide-Field High-Resolution Cone-Beam Computed Tomography for Cerebral Angiography: A Phantom Study

There has been an increase in the use of interventional neuroradiology procedures because of their non-invasiveness compared to surgeries and the improved image quality of fluoroscopy, digital subtraction angiography, and rotational angiography. Although cone-beam computed tomography (CBCT) images are inferior to multi-detector CT images in terms of low-contrast detectability and lower radiation doses, CBCT scans are frequently performed because of their accessibility. This study aimed to evaluate the image quality and radiation dose of two different high-resolution CBCTs (HR CBCT): conventional (C-HR CBCT) and wide-field HR CBCT (W-HR CBCT). The modulation transfer function (MTF), noise power spectrum (NPS), and contrast-to-noise ratio (CNR) were used to evaluate the image quality. On comparing the MTF of C-HR CBCT with a 256 × 256 matrix and that of W-HR CBCT with a 384 × 384 matrix, the MTF of W-HR CBCT with the 384 × 384 matrix was larger. A comparison of the NPS and CNR of C-HR CBCT with a 256 × 256 matrix and W-HR CBCT with a 384 × 384 matrix showed that both values were comparable. The reference air kerma values were equal for C-HR CBCT and W-HR CBCT; however, the value of the kerma area product was 1.44 times higher for W-HR CBCT compared to C-HR CBCT. The W-HR CBCT allowed for improved spatial resolution while maintaining the image noise and low-contrast detectability by changing the number of image matrices from 256 × 256 to 384 × 384. Our study revealed the image characteristics and radiation dose of W-HR CBCT. Given its advantages of low-contrast detectability and wide-area imaging with high spatial resolution, W-HR CBCT may be useful in interventional neuroradiology for acute ischemic stroke.

Safety and efficacy of transgraft internal trapping after proximal internal carotid artery ligation with high-flow bypass

OBJECTIVE

Proximal internal carotid artery (ICA) ligation with high-flow bypass is an important vascular reconstructive technique for giant ICA aneurysms or skull base tumors involving the ICA to control intraoperative bleeding. Retrograde or collateral blood flow occasionally remains postoperatively and requires complete internal trapping. Although transgraft internal trapping is one of the options, there are few reports on transgraft treatment. The purpose of this study was to report our experience of transgraft internal trapping and evaluate the safety and efficacy of this procedure.

METHODS

We retrospectively selected patients who underwent transgraft internal trapping after proximal ICA ligation with high-flow bypass between January 2012 and June 2020.

RESULTS

We encountered five cases of this procedure (one aneurysm case and four tumor cases). The median duration between the bypass and transgraft internal trapping was 12 days. In four out of five cases, a guiding catheter could be placed in the graft. No disruption of the anastomosis was observed. Transgraft internal trapping was achieved in all five cases with detachable coils. All treatments could be completed safely without any adverse events, including ischemic and hemorrhagic complications.

CONCLUSIONS

Transgraft internal trapping after proximal ICA ligation with high-flow bypass may be an option for preventing residual retrograde blood flow.

The Influence of Aneurysm Size on the Outcomes of Endovascular Management for Aneurysmal Subarachnoid Hemorrhages: A Comparison of the Treatment Results of Patients with Large and Small Aneurysms

The influence of aneurysm size on the outcomes of endovascular management (EM) for aneurysmal subarachnoid hemorrhages (aSAH) is poorly understood. To evaluate the outcomes of EM for ruptured large cerebral aneurysms, we retrospectively analyzed the medical records of patients with aSAH that were treated with coiling between 2013 and 2020 and compared the differences in outcomes depending on aneurysm size. A total of 469 patients with aSAH were included; 73 patients had aneurysms measuring ≥10 mm in diameter (group L), and 396 had aneurysms measuring <10 mm in diameter (group S). The median age; the percentage of patients that were classified as World Federation of Neurological Surgeons grade 1, 2, or 3; and the frequency of intracerebral hemorrhages differed significantly between group L and group S (p = 0.0105, p = 0.0075, and p = 0.0458, respectively). There were no significant differences in the frequencies of periprocedural hemorrhagic or ischemic events. Conversely, rebleeding after the initial treatment was significantly more common in group L than in group S (6.8% vs. 2.0%; p = 0.0372). The frequency of a modified Rankin Scale score of 0-2 at discharge was significantly lower (p = 0.0012) and the mortality rate was significantly higher (p = 0.0023) in group L than in group S. After propensity-score matching, there were no significant differences in complications and outcomes between the two groups. Rebleeding was more common in large aneurysm cases. However, propensity-score matching indicated that the outcomes of EM for aSAH may not be affected markedly by aneurysm size.

An Initial High National Institutes of Health Stroke Scale Score and Any Intracranial Hemorrhage Are Independent Factors for a Poor Outcome in Nonagenarians Treated with Thrombectomy for Acute Large Vessel Occlusion: The Tokyo/Tama-REgistry of Acute Endovascular Thrombectomy (TREAT) Study

BACKGROUND

Mechanical thrombectomy (MT) is effective in acute ischemic stroke patients ≥80 years old with large vessel occlusion (LVO). However, data for patients ≥90 years old remain very limited, and factors influencing functional outcomes are unclear. This study aimed to investigate factors influencing functional outcomes in patients ≥90 years old treated with MT for acute LVO.

METHODS

This retrospective observational study used prospectively collected data from the Tokyo/tama-REgistry of Acute endovascular Thrombectomy (TREAT) study. Inclusion criteria were as follows: 1) patients ≥90 years old treated with MT for LVO and 2) prestroke modified Rankin Scale (mRS) score, 0-3. The functional outcome was defined based on the mRS score at 90 days after the procedure: good functional outcome, mRS score 0-3 and poor functional outcome, mRS score 4-6.

RESULTS

Data were analyzed for 104 patients ≥90 years old. The good functional outcome was observed in 25 patients (24.0%), and the poor functional outcome was observed in the remaining 79 patients. Significant differences were identified in initial National Institutes of Health Stroke Scale (NIHSS) score, modified Thrombolysis in Cerebral Infarction grade 2b-3, modified Thrombolysis in Cerebral Infarction grade 3, and any intracranial hemorrhage and hemorrhagic infarction in univariate analyses. Multivariable analysis confirmed the initial NIHSS score (odds ratio, 1.08; 95% confidence interval, 1.01-1.17; P = 0.045) and any intracranial hemorrhage (odds ratio, 11.6; 95% confidence interval, 1.43-95.0; P = 0.022) as independent factors for the functional outcome.

CONCLUSIONS

An initial high NIHSS score and any intracranial hemorrhage are independent factors for the poor functional outcome in acute ischemic stroke patients ≥90 years old treated with MT.

Evaluation of Peak Skin Doses and Lens Doses during Interventional Neuroradiology Using a Direct Measurement System

Objective

In interventional neuroradiology (INR), the evaluation of the peak skin dose (PSD) and lens dose is important because the patient radiation dose increases in cases in which the procedure is more difficult and complex. This study evaluated the radiation doses during INR procedures using a direct measurement system.

Methods

Radiation dose measurements during INR were performed in 332 patients with unruptured aneurysm (URAN), dural arteriovenous fistula (DAVF), and arteriovenous malformation (AVM). The PSD and bilateral lens doses were analyzed for each disease. The Pearson correlation test was used to determine whether the PSD and lens doses were linearly related to the reference air kerma (K_a,r).

Results

In all cases, the PSD and right and left lens doses were 2.36 ± 1.28 Gy, 114.2 ± 54.6 mGy, and 189.8 ± 160.3 mGy, respectively. The PSD and lens doses of the DAVF and AVM cases were significantly higher than those of the URAN case. The Pearson correlation test revealed statistically significant positive correlations between K_a,r and PSD, K_a,r and right lens dose, and K_a,r and left lens dose.

Conclusion

The characteristics of radiation dose in INR were clarified. Owing to the concern of increased radiation doses exceeding the threshold values in DAVF and AVM cases, protection from radiation is required. Simple regression analysis revealed the possibility of precisely predicting PSD using K_a,r.

Perioperative and long-term complications following therapeutic internal carotid artery occlusion

BACKGROUND

Parent artery occlusion (PAO) is an effective treatment for hemorrhagic diseases associated with the internal carotid artery. There are several reports of long-term cerebral infarction or the formation of de novo cerebral aneurysms following PAO.

MATERIALS AND METHODS

We retrospectively reviewed these complications in 38 patients who underwent PAO for therapeutic treatment. We investigated perioperative cerebral infarctions, long-term cerebral infarctions, and de novo aneurysms.

RESULTS

The mean age of the patients was 64.0 years, and 25 patients (65.8%) were female. The causative diseases were unruptured (n = 19; 50.0%) and ruptured (n = 8; 21.1%) aneurysms. PAO was performed after ischemic tolerance was assessed with balloon test occlusion (BTO), and BTO was performed in 34 patients, of whom 25 (73.5%) had ischemic tolerance. Twenty-six patients (68.4%) were treated with PAO alone, eight (23.5%) with low-flow bypass, and six (17.6%) with high-flow bypass. Perioperative complications occurred in five patients (13.2%): two of the 26 patients (7.7%) who underwent scheduled treatment and three of the 12 patients (25.0%) who underwent emergency treatment. One patient (2.6%) had long-term de novo aneurysm, and none developed cerebral infarction.

CONCLUSIONS

These results showed that the assessment of ischemic tolerance by performing BTO and appropriate revascularization in scheduled treatments are important to reduce perioperative and long-term cerebral infarctions. PAO must be performed with greater caution in emergency treatment.

Lens dose reduction with a bismuth shield in neuro cone-beam computed tomography: an investigation on optimum shield device placement conditions

This study aimed to determine the placement distance, number, and position of the bismuth shield for developing a lens protective device for cone-beam computed tomography (CBCT). To determine the dose reduction rate, the lens doses were measured using an anthropomorphic head phantom and a real-time dosimeter. The image quality assessment was determined by analyzing the change in the pixel value, caused by the bismuth shield, and the artifact index was calculated from the pixel value and image noise within various regions of interest in the head phantom. When the distance between the bismuth shield and the subject was increased, the image quality deteriorated less, but there was also a decrease in the lens dose reduction rate. Upon changing the number of bismuth shields from 1-ply to 2-ply, the dose reduction rate increased; however, there was a decrease in the image quality. Additionally, placing the bismuth shield outside of the subject improved the dose reduction rate without deteriorating the image quality. The optimum placement conditions of the bismuth shield were concluded as follows: positioned outside, placed 10 mm from the surface of the subject, and used a 1-ply bismuth shield. When these placement conditions were used, the lens dose reduction rate was 26.9 ± 0.36% (right-left average) for the "bismuth shield: separate". The protective device developed in this study will contribute to radiation dose reduction in CBCT scans.

Antiplatelet Therapy and Periprocedural Risk Factor Analysis for Pipeline Embolization Device Treatment of Unruptured Internal Carotid Artery Aneurysms: A Retrospective, Multicenter Analysis

BACKGROUND

Aneurysm treatment using the Pipeline Embolization Device has been established but appropriate maintenance of dual antiplatelet therapy (APT) is essential. This multicenter retrospective study assessed whether APT was properly adjusted for clopidogrel resistance and identified risk factors associated with periprocedural complications.

METHODS

Consecutive cases of use of the Pipeline Embolization Device for internal carotid artery aneurysms (>10 mm) between November 2015 and April 2020 were analyzed. Dual APT (aspirin + clopidogrel) was prescribed before treatment. If preprocedural P2Y12 reaction unit (PRU) values were >240, APT was adjusted. Periprocedural complications were compared between APT nonadjustment and adjustment groups and periprocedural risk factors were also analyzed.

RESULTS

A total of 162 procedures were assessed. The mean maximum aneurysm size was 15.35 mm. APT adjustment was required in 47 cases (29.0%), primarily by switching to prasugrel. There were no significant differences in complication incidence between the 2 groups even after propensity score matching. The risk factor independently associated with ischemic complications was a neck size of 8 mm or larger (odds ratio [OR], 5.25; P = 0.018) and restricting analysis to the APT nonadjustment group showed PRU values of 190 or higher (OR, 5.84; P = 0.047) and neck sizes of 8 mm or larger (OR, 7.05; P = 0.029) as significant factors. The risk factor independently associated with hemorrhagic complications was a neck size of 7 mm or larger (OR, 11.57; P = 0.023).

CONCLUSIONS

APT adjustment for clopidogrel resistance was safe and effective. Neck width was a risk factor for both ischemic and hemorrhagic complications. PRU values of 190 or higher were also associated with ischemic complications.

Intravenous Alteplase is Associated with First Pass Effect in Stent-retriever but not ADAPT Thrombectomy : Post Hoc Analysis of the SKIP Study

PURPOSE

To investigate the effect of alteplase, either combined with stent-retriever thrombectomy or a direct aspiration first pass technique (ADAPT), in patients with large-vessel occlusion stroke.

METHODS

This was a retrospective post hoc analysis of data from The Direct Mechanical Thrombectomy in Acute LVO Stroke (SKIP) study. Patients were divided into two groups according to the first-line thrombectomy technique: stent-retriever and ADAPT. Each group was further divided into two subgroups, namely MT and MT + alteplase. The procedural outcomes, such as first pass effect (FPE) ratio and number of passes, were evaluated. The clinical outcomes included mRS score at 3 months.

RESULTS

A total of 180 patients were included (116 in the stent-retriever group and 64 in the ADAPT group). No interaction was detected between the first-line technique and alteplase administration. In the stent-retriever group, after adjusting for factors associated with FPE, the adjusted odds ratio (95% confidence interval) of FPE of the MT + alteplase subgroup versus the MT subgroup was 3.57 (1.5-8.48) and in the ADAPT group it was 1.35 (0.37-4.91). With alteplase, the number of passes decreased with adjusted odds ratios of 0.59 (0.37-0.93) in the stent-retriever group but not in the ADAPT group. In both first-line technique groups, clinical outcomes did not differ between subgroups.

CONCLUSION

In the SKIP study, alteplase administration was associated with increased FPE when combined with stent-retriever thrombectomy, but not with ADAPT. We found no differences in the clinical outcomes.

Large cavernous carotid artery aneurysm with spontaneous thrombosis: is there more to a change in morphology than there seems to be? Illustrative case

BACKGROUND

The pathogenesis and endovascular treatment strategy for spontaneously thrombosed unruptured cerebral aneurysms have not yet been comprehensively described.

OBSERVATIONS

The authors reported on a 78-year-old woman who had large bilateral unruptured cavernous carotid artery aneurysms that induced chronic disseminated intravascular coagulation and acquired factor XIII deficiency. The right aneurysm was symptomatic and partially thrombosed. Hemorrhagic diathesis and abnormal values of laboratory data improved after administration of recombinant human thrombomodulin followed by endovascular treatment in which three pipeline embolization devices were deployed for the right aneurysm.

LESSONS

To the best of the authors’ knowledge, this was the first report of an unruptured cerebral aneurysm leading to coagulation disorders with clinical manifestation that was treated successfully by endovascular intervention after intensive perioperative management.

Small Unruptured Aneurysm Verification-prevention Effect against Growth of Cerebral Aneurysm Study Using Statin

Several basic experimental studies have demonstrated that statins have beneficial effects for intracranial aneurysm (IA). Clinical studies on unruptured IAs, however, remain limited to four retrospective studies that have reached different conclusions. This study was the first open-label, multicenter, randomized controlled trial to assess the preventive effects of atorvastatin. Patients with unruptured small saccular IAs were randomly assigned to statin and control groups. The primary endpoint was a composite of aneurysm growth of ≥0.5 mm, new bleb formation confirmed from magnetic resonance (MR) angiography, and rupture. Enrollment was prematurely terminated due to unexpectedly slow enrollment. Of 231 patients (275 target IAs), 110 patients (128 IAs) were randomly assigned to the statin group and 121 patients (147 IAs) to the control group. After excluding 22 dropout patients, 107 IAs in the 93 statin group patients and 140 IAs in the 116 control group patients were finally analyzed. No significant differences of basic characteristics were evident between groups, except for significantly higher systolic pressure in the statin group (P = 0.03). The primary endpoint occurred in 28 IAs (20.0%) in the control group and in 17 IAs (15.9%) in the statin group. No aneurysm rupture was confirmed in either group. Significant beneficial effects of statin for IAs were not demonstrated for the primary endpoint (log-rank P = 0.359). This randomized trial did not establish any preventive effects of atorvastatin for unruptured small IAs. Further studies of larger cohorts are required to clarify the efficacy of statins for patients with unruptured IAs.

Clinical trial registration: UMIN000005135

Long-term Durability of Coil Embolization for Unruptured Aneurysm after Introduction of the Neck-bridge Stent: Comparison between the Pre-stent Era and the Stent Era

More complex aneurysms can be treated by coil embolization with neck-bridge stent assistance. However, concerns about postprocedural ischemic or hemorrhagic complications remain. In this study, we assessed the long-term durability after introduction of neck-bridge stent in the context of coil embolization for unruptured aneurysm by comparing re-treatment and neurological events between the pre-stent and stent eras. Unruptured aneurysms treated by coil embolization between April 2005 and May 2018 were analyzed retrospectively. We divided cases into two groups: the pre-stent era and the stent era. The cumulative rate of re-treatment and neurological events were assessed and compared. During the period, 177 aneurysms were treated in the pre-stent era and 354 aneurysms were treated in the stent era. The median follow-up was 55 months. In the stent era, the dome/neck (D/N) ratio was significantly lower (P <0.001) and the number of aneurysms located at the posterior circulation was higher (P <0.001). A stent was used in 31.92% of cases in the stent era. The cumulative rate of re-treatment was significantly higher in the pre-stent era than it was in the stent era in univariate and multivariate analyses (P = 0.008, P = 0.008, respectively). The cumulative rate of neurological events was not significantly different between the two groups. The re-treatment rate has been improved without increasing neurological complications after introduction of the neck-bridge stent.

Comparisons of Characteristics and Outcomes after Mechanical Thrombectomy for Vertebrobasilar Occlusion with Cardioembolism or Atherosclerotic Brain Infarction: Data from the Tokyo-Tama-Registry of Acute Endovascular Thrombectomy (TREAT)

BACKGROUND

Some reports suggest the efficacy of mechanical thrombectomy (MT) for acute vertebrobasilar artery (VBA) occlusion. The major causes of VBA occlusion include cardioembolism (CE) and large-artery atherosclerosis (LAA). However, the clinical characteristics of each cause remain unclear, and they might be important for decision making related to the indications and strategy of MT.

OBJECTIVE

This study aimed to compare functional outcomes and factors affecting outcomes between patients with CE and LAA with acute VBA occlusion.

METHODS

This was a retrospective and prospective observational study using data from TREAT (Tokyo-Tama-Registry of Acute Endovascular Thrombectomy), a multicenter registry of MT for acute large-vessel occlusion in the Tokyo metropolitan area. Patients with VBA occlusion classified into CE and LAA groups were analyzed. The primary outcome was a modified Rankin Scale score of 0-2 at 90 days.

RESULTS

Seventy-nine patients (57 with CE and 22 with LAA) were eligible from January 2015 to March 2020. Despite significantly shorter puncture-to-recanalization and onset-or-last-well-known-to-recanalization times in the CE group, the primary outcome was not significantly different between the 2 groups (CE, 31.6% vs. LAA, 45.5%; P = 0.248). In the subgroup analysis, patients with CE had worse clinical outcomes in the onset-or-last-well-known-to-door time ≥180 minutes, onset-or-last-well-known-to-door time ≥300 minutes, and low posterior circulation Alberta Stroke Program Early CT Score (≤7) subgroups.

CONCLUSIONS

Functional outcomes of VBA occlusion were not significantly different between CE and LAA. Based on the subgroup analysis, patients with CE might have poorer collateral status than do patients with LAA, and earlier recanalization might therefore be desired.

Effect of Mechanical Thrombectomy Without vs With Intravenous Thrombolysis on Functional Outcome Among Patients With Acute Ischemic Stroke: The SKIP Randomized Clinical Trial

IMPORTANCE

Whether intravenous thrombolysis is needed in combination with mechanical thrombectomy in patients with acute large vessel occlusion stroke is unclear.

OBJECTIVE

To examine whether mechanical thrombectomy alone is noninferior to combined intravenous thrombolysis plus mechanical thrombectomy for favorable poststroke outcome.

DESIGN, SETTING, AND PARTICIPANTS

Investigator-initiated, multicenter, randomized, open-label, noninferiority clinical trial in 204 patients with acute ischemic stroke due to large vessel occlusion enrolled at 23 hospital networks in Japan from January 1, 2017, to July 31, 2019, with final follow-up on October 31, 2019.

INTERVENTIONS

Patients were randomly assigned to mechanical thrombectomy alone (n = 101) or combined intravenous thrombolysis (alteplase at a 0.6-mg/kg dose) plus mechanical thrombectomy (n = 103).

MAIN OUTCOMES AND MEASURES

The primary efficacy end point was a favorable outcome defined as a modified Rankin Scale score (range, 0 [no symptoms] to 6 [death]) of 0 to 2 at 90 days, with a noninferiority margin odds ratio of 0.74, assessed using a 1-sided significance threshold of .025 (97.5% CI). There were 7 prespecified secondary efficacy end points, including mortality by day 90. There were 4 prespecified safety end points, including any intracerebral hemorrhage and symptomatic intracerebral hemorrhage within 36 hours.

RESULTS

Among 204 patients (median age, 74 years; 62.7% men; median National Institutes of Health Stroke Scale score, 18), all patients completed the trial. Favorable outcome occurred in 60 patients (59.4%) in the mechanical thrombectomy alone group and 59 patients (57.3%) in the combined intravenous thrombolysis plus mechanical thrombectomy group, with no significant between-group difference (difference, 2.1% [1-sided 97.5% CI, -11.4% to ∞]; odds ratio, 1.09 [1-sided 97.5% CI, 0.63 to ∞]; P = .18 for noninferiority). Among the 7 secondary efficacy end points and 4 safety end points, 10 were not significantly different, including mortality at 90 days (8 [7.9%] vs 9 [8.7%]; difference, -0.8% [95% CI, -9.5% to 7.8%]; odds ratio, 0.90 [95% CI, 0.33 to 2.43]; P > .99). Any intracerebral hemorrhage was observed less frequently in the mechanical thrombectomy alone group than in the combined group (34 [33.7%] vs 52 [50.5%]; difference, -16.8% [95% CI, -32.1% to -1.6%]; odds ratio, 0.50 [95% CI, 0.28 to 0.88]; P = .02). Symptomatic intracerebral hemorrhage was not significantly different between groups (6 [5.9%] vs 8 [7.7%]; difference, -1.8% [95% CI, -9.7% to 6.1%]; odds ratio, 0.75 [95% CI, 0.25 to 2.24]; P = .78).

CONCLUSIONS AND RELEVANCE

Among patients with acute large vessel occlusion stroke, mechanical thrombectomy alone, compared with combined intravenous thrombolysis plus mechanical thrombectomy, failed to demonstrate noninferiority regarding favorable functional outcome. However, the wide confidence intervals around the effect estimate also did not allow a conclusion of inferiority.

TRIAL REGISTRATION

umin.ac.jp/ctr Identifier: UMIN000021488.

Suspected Cerebral Hyperperfusion Syndrome after Stenting for Intracranial Vertebral Artery Stenosis Associated with Reduced Cerebral Blood Flow to the Posterior Cerebral Artery Territory

Objective

Although several studies have reported on cerebral hyperperfusion syndrome (CHS)/hyperperfusion phenomenon (HPP) involving the anterior circulation after carotid artery stenting (CAS), little is known about CHS/HPP involving the posterior circulation after percutaneous transluminal angioplasty (PTA) and stenting of the vertebral artery (VA).

Case Presentation

A 79-year-old man with known chronic occlusion of the left VA (V4 segment) was admitted to another hospital with right-sided hemiplegia, mild disturbance of consciousness, and dysphagia. A head MRI revealed multiple infarcts in posterior circulation areas, and severe stenosis of the right VA (V4 segment). Single photon emission computed tomography (SPECT) indicated reduced cerebral blood flow (CBF) in the posterior circulation, and DSA revealed 76% stenosis of the right V4 segment. On day 18, PTA/stenting was performed under general anesthesia for the severe stenosis of the right VA. However, head MRI and CT on postoperative day (POD)1 showed intracranial hemorrhage (ICH) occupying an area measuring 2 cm in diameter in the left posterior lobe and a small subdural hematoma (SDH). SPECT on POD1 indicated increased CBF in the posterior lobe, and we diagnosed CHS might have caused ICH. Although SPECT on POD4 showed residual hyperperfusion, SPECT on POD11 revealed reduced CBF in the posterior circulation area.

Conclusion

Our patient developed ICH after undergoing PTA/stenting for known severe symptomatic stenosis of the right VA. CHS/HPP in the posterior cerebral artery territory might be one of the etiologies, and reduced CBF prior to the procedure could be a risk factor for CHS/HPP developing after PTA/stenting.

Mechanically Induced Vasospasm and Postoperative Cerebral Infarction after Coil Embolization of Unruptured Cerebral Aneurysms in Anterior Circulation

We occasionally encounter situations which requires retraction of the guiding system or administration of vasodilatory agents for mechanically induced vasospasm (MVS). However, whether MVS is associated with postoperative cerebral infarction has not been reported.To explore factors associated with MVS and to verify how MVS influences procedure outcomes,we reviewed consecutive cases of unruptured aneurysms in the anterior circulation treated with coil embolization between January 2017 and February 2020. Collected data included patients' clinical characteristics, devices, vessel tortuosity, severity of MVS, diameter of the parent vessel, and procedure duration. Significant MVS was defined as a condition necessitating a pause in the procedure. We also counted postoperative diffusion-weighted imaging (DWI) hyperintense spots (DHS). Parameters associated with MVS and postoperative DHS were investigated by multivariate logistic regression.A total of 103 cases met the eligibility criteria, with significant MVS occurring in 21 cases (20.3%), and postoperative DHS (≥3) confirmed in 30 cases (29.1%). Significant MVS was associated only with larger caliber at the tip of the guiding system compared with the parent vessel (p = 0.001). Postoperative DHS was associated with significant MVS (p = 0.002, OR: 5.313; 95% CI: 1.851-15.254).Significant MVS is a predictor of postoperative cerebral ischemia and occurs in patients with smaller caliber of the parent vessel. In patients with high-risk features for MVS, we should avoid navigating the guiding system forcibly through the narrow parent vessel. In other words, it is crucial to place the large-caliber guiding sheath/catheter proximally and only guide distally the intermediate catheter with better trackability.

Risk factors for medullary infarction after endovascular trapping of vertebral artery dissecting aneurysms

Internal trapping (IT) is a treatment option for intracranial vertebral artery dissecting aneurysms (VADAs). Medullary infarction (MI) is a complication linked to this treatment. This study aims to clarify the outcomes of IT for VADAs and the risk factors for MIs. We retrospectively reviewed the databases from 2010 to 2017 to identify patients with VADAs treated by IT at seven collaborating institutions. Radiological findings, clinical courses, and outcomes were analyzed. Perforating arteries were classified into terminal or longitudinal types using preoperative angiography. IT was completed in 90 patients (74 ruptured and 16 unruptured VADA). Postoperative rebleeding did not occur in any ruptured VADA patients. Postoperative MRI detected MIs in 26 patients (28.9%). The incidence of MIs in the ruptured VADA (32%) was higher compared with that in the unruptured VADA (13%), though it was not significant. In the MI group, the occlusion or blind alley of the terminal-type and longitudinal-type perforator was confirmed in 23 patients (88%) and 11 patients (42%), respectively. The occlusion or blind alley of the terminal-type perforator was an independent risk factor for MIs in the logistic regression analysis (OR 5.81; 95% CI 1.34-25.11; p = 0.018). In ruptured VADA, postoperative MI (OR 12.2; 95% CI 3.19-64.55; p = 0.0001) and high-grade SAH (OR 8.02; 95% CI 2.32-37.70; p = 0.0006) were independent risk factors of an unfavorable clinical outcome. In conclusion, MIs were an independent risk factor for unfavorable outcomes after IT, especially for a ruptured VADA. The occlusion or blind alley of the terminal-type perforator caused by the IT was associated with postoperative MIs.

Ruptured Mycotic Cerebral Aneurysm Secondary to Disseminated Nocardiosis

We report a case of a ruptured mycotic cerebral aneurysm caused by Nocardia infection. A 22-year-old immunocompromised woman with adult-onset Still's disease developed a subarachnoid hemorrhage (SAH). Digital subtraction angiography revealed a small aneurysm at the M2-3 bifurcation of the right middle cerebral artery. Cardiac ultrasonography showed vegetation at the posterior cardiac wall, suspecting infective endocarditis (IE). Gram-positive filamentous bacteria were observed in the necrotic tissue surrounding the aneurysm obtained during trapping surgery. Long-term blood culture showed that the cause of her cerebral mycotic aneurysm was nocardiosis. A mycotic ruptured cerebral aneurysm is an important cause of SAH in immunocompromised patients. Early diagnosis of IE, detection of gram-positive rods by Gram staining, and long-term culture to identify the bacteria is crucial in diagnosing nocardiosis.

Delineability and anatomical variations of perforating arteries from normal vertebral artery on 3D DSA: implications for endovascular treatment of dissecting aneurysms

BACKGROUND AND PURPOSE

Endovascular trapping of the vertebral artery dissecting aneurysms (VADAs) carries a risk of medullary infarction due to the occlusion of the perforating arteries. We evaluated the detectability and anatomical variations of perforating arteries arising from the vertebral artery (VA) using three-dimensional DSA.

METHODS

In 120 patients without VA lesions who underwent rotational vertebral arteriography, the anatomical configurations of perforating arteries from the VA were retrospectively evaluated on the bi-plane DSA and reconstructed images to reach the consensus between two experienced reviewers. The images were interpreted by focusing on the numbers and types of perforating arteries, the relationships between the number of perforators and the anatomy of the VA and its branches.

RESULTS

Zero, 1, 2, 3, 4, and 6 perforators were detected in 2, 51, 56, 9, 1, and 1 patient, respectively (median of 2 perforators per VA). The 200 perforators were classified into 146 terminal and 54 longitudinal course types and into 32 ventral, 151 lateral, and 17 dorsolateral distribution types. All ventral type perforators were also terminal type. In contrast, the longitudinal type was seen in 28.5% of lateral types and in 65% of dorsolateral types. Regarding the difference in the origin of the posterior inferior cerebellar artery (PICA), non-PICA type VAs gave off larger number of perforators than the other types of VAs.

CONCLUSIONS

Non-PICA type VAs give off a significantly larger number of perforators than other types, indicating that the trapping of non-PICA type VAs is associated with a risk of ischemic complications.

TREATMENT OF INTERNAL CAROTID ANEURYSMS USING PIPELINE EMBOLIZATION DEVICES: MEASURING THE RADIATION DOSE OF THE PATIENT AND DETERMINING THE FACTORS AFFECTING IT

The purpose of this study was to measure the peak skin dose (PSD) and bilateral lens doses using radiophotoluminescence glass dosimeters and to determine the factors influencing the radiation dose in cases of cerebral aneurysm treated with pipeline embolization devices (PEDs). The cumulative dose, PSD and right and left lens doses were 3818.1 ± 1604.6, 1880.0 ± 723.0, 124.8 ± 49.2 and 180.7 ± 124.8 mGy, respectively. Using multivariate analysis, body mass index (p < 0.01; odds ratio (OR) = 1.806; 95% confidence interval (CI) = 1.007-3.238) and deployment time of PED (p < 0.05; OR = 1.107; 95% CI = 1.001-1.224) were found to be the independent predictors of PSD exceeding 2 Gy. Measures such as collimation of the radiation field and optimization of radiation dose should be taken to reduce the radiation to the patient.

Clinical Outcome of Patients With Large Vessel Occlusion and Low National Institutes of Health Stroke Scale Scores

Background and Purpose—

The treatment and prognosis of acute large vessel occlusion with mild symptoms have not been sufficiently studied. The present study aimed to investigate the clinical or radiological predictors of clinical outcome in patients with stroke with mild symptoms due to acute large vessel occlusion.

Methods—

Of 2420 patients with acute large vessel occlusion in the RESCUE-Japan Registry 2 (Recovery by Endovascular Salvage for Cerebral Ultra-Acute Embolism-Japan Registry 2), a multicenter prospective registry in Japan, patients with modified Rankin Scale scores of 0 to 2 before onset and initial National Institutes of Health Stroke Scale (NIHSS) scores of 0 to 5 were examined in post hoc analysis. We examined the clinical and radiological characteristics associated with a favorable outcome (modified Rankin Scale score, 0–2 at 90 days) using multivariate analysis, as well as the factors associated with a favorable outcome in patients treated with endovascular therapy.

Results—

We analyzed 272 patients (median age, 73 years; median NIHSS score on admission, 3). Eighty-six (31.6%) patients were treated with intravenous recombinant tissue-type plasminogen activator, 54 (19.9%) underwent endovascular therapy, and 208 (76.5%) showed a favorable outcome. In multivariate analysis, age <75 years (odds ratio [OR], 2.42 [95% CI, 1.30–4.50]), initial NIHSS score 0 to 3 (OR, 3.08 [95% CI, 1.59–5.98]), intravenous recombinant tissue-type plasminogen activator (OR, 2. 86 [95% CI, 1.32–6.21]), and blood glucose level ≤140 mg/dL (OR, 2.37 [95% CI, 1.22–4.60]) were independently associated with a favorable outcome. However, endovascular therapy was not associated with a favorable outcome (OR, 1.65 [95% CI, 0.71–3.88]). Among 54 patients treated with endovascular therapy, good reperfusion status was more common in the favorable outcome group (88.6% versus 60.0%; P <0.05).

Conclusions—

Younger age, lower initial NIHSS score, intravenous recombinant tissue-type plasminogen activator, and absence of hyperglycemia were independently associated with a favorable outcome in patients with acute large vessel occlusion with low NIHSS scores.

Registration—

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02419794.

Retrograde three-dimensional rotational angiography: A novel method for the detection of plaque protrusion during carotid artery stenting under continuous distal balloon protection

BACKGROUND

To prevent ischemic complications during carotid artery stenting, accurate detection of plaque protrusion and appropriate additional treatment are essential. Here, we introduce a novel method for the detection of plaque protrusion under distal balloon protection using three-dimensional rotation angiography-"retrograde 3DRA." We evaluated the safety and efficacy of this method.

MATERIALS AND METHODS

We retrospectively analyzed 28 consecutive carotid artery stenting procedures under distal balloon protection at our hospital between July 2017 and August 2019. The first line of protection was dual balloon protection (proximal and distal balloon). After stent deployment, balloon dilatation, and subsequent blood aspiration, 3DRA was performed with the injection of diluted contrast medium from the aspiration catheter positioned just proximal to the distal protection balloon. The stent lumen was analyzed by obtaining the reconstruction maximum intensity projection image.

RESULTS

Among the 28 cases, all cases could be assessed for in-stent plaque protrusion using "retrograde 3DRA." We were able to evaluate the stent lumen clearly. There were three cases (10.7%) in which plaque protrusion could be confirmed. Since additional balloon dilatation was performed for all protrusion cases under continuing balloon protection, no ischemic complications occurred.

CONCLUSION

Retrograde 3DRA could be safe and useful for the detection of plaque protrusions and to avoid ischemic complication for tolerable cases of internal carotid artery transient balloon protection.

Clinical Characteristics and Endovascular Treatment for Spinal Dural Arteriovenous Fistula in Japan: Japanese Registry of Neuroendovascular Therapy 2 and 3

A subgroup analysis of spinal vascular lesions registered in the Japanese Registry of Neuroendovascular Therapy 2 (JR-NET2) and JR-NET3 was performed. About 172 analyzable cases of spinal dural arteriovenous fistula (SDAVF) were assessed, including the characteristics, treatment strategy, and treatment outcome. SDAVF was more common in middle-aged and older males. The most commonly affected area was the thoracolumbosacral region (83.7%), and most cases had a non-hemorrhagic onset (89.0%). Complete obliteration was achieved in 54.7%. Treatment-related complications occurred in three patients (7.0%). Post-treatment neurological improvement was achieved in 48.3%. The primary endpoint [modified Rankin Scale (mRS) score of 0–2 on postoperative day 30] was achieved in 60.5% of the cases. As a new discovery, the incidence of cervical SDAVF increased from 1.8% in JR-NET2 to 19.7% in JR-NET3. Compared with non-cervical SDAVF, cervical SDAVF was characterized by a higher proportion of hemorrhagic onset (P <0.01), incomplete obliteration of the shunt (P <0.01), and embolization-related complications (P = 0.01). Overall, a mRS of 0–2 on postoperative day 30 was correlated with a pre-treatment mRS of 0–2 (P <0.01) in a univariate analysis. Complete obliteration of the shunt was the only predictor of postoperative neurological improvement (P = 0.001) in a multivariate analysis. Endovascular treatment for SDAVF has been safely administered in Japan. The incidence of cervical SDAVF, which has more aggressive features, appears to be increasing. Early diagnosis and complete obliteration of the shunt are important for improving the treatment outcomes of patients with SDAVF.

Comparing Retreatments and Expenditures in Flow Diversion Versus Coiling for Unruptured Intracranial Aneurysm Treatment: A Retrospective Cohort Study Using a Real-World National Database

BACKGROUND

Flow diverters (FDs) have marked the beginning of innovations in the endovascular treatment of large unruptured intracranial aneurysms, but no multi-institutional studies have been conducted on these devices from both the clinical and economic perspectives.

OBJECTIVE

To compare retreatment rates and healthcare expenditures between FDs and conventional coiling-based treatments in all eligible cases in Japan.

METHODS

We identified patients who had undergone endovascular treatments during the study period (October 2015-March 2018) from a national-level claims database. The outcome measures were retreatment rates and 1-yr total healthcare expenditures, which were compared among patients who had undergone FD, coiling, and stent-assisted coiling (SAC) treatments. The coiling and SAC groups were further categorized according to the number of coils used. Retreatment rates were analyzed using Cox proportional hazards models, and total expenditures were analyzed using multilevel mixed-effects generalized linear models.

RESULTS

The study sample comprised 512 FD patients, 1499 coiling patients, and 711 SAC patients. The coiling groups with ≥10 coils and ≥9 coils had significantly higher retreatment rates than the FD group with hazard ratios of 2.75 (1.30-5.82) and 2.52 (1.24-5.09), respectively. In addition, the coiling group with ≥10 coils and SAC group with ≥10 coils had significantly higher 1-year expenditures than the FD group with cost ratios (95% CI) of 1.30 (1.13-1.49) and 1.31 (1.15-1.50), respectively.

CONCLUSION

In this national-level study, FDs demonstrated significantly lower retreatment rates and total expenditures than conventional coiling with ≥ 9 coils.

ESTIMATION OF PATIENT LENS DOSE ASSOCIATED WITH C-ARM CONE-BEAM COMPUTED TOMOGRAPHY USAGE DURING INTERVENTIONAL NEURORADIOLOGY

The purpose of this study was to investigate the dose distribution and lens doses associated with C-arm cone-beam computed tomography (CBCT), using a head phantom, and to estimate the contribution ratio of C-arm CBCT to each patient's lens dose during interventional neuroradiology ('lens dose ratio') in 109 clinical cases. In the phantom study, the peak skin doses and respective right and left lens doses of C-arm CBCT were as follows: 63.0 ± 1.9 mGy, 19.7 ± 1.4 mGy and 21.9 ± 0.8 mGy in whole brain C-arm CBCT and 39.2 ± 1.4 mGy, 4.7 ± 0.9 mGy and 3.6 ± 0.3 mGy in high-resolution C-arm CBCT. In the clinical study, the lens dose ratios were 25.4 ± 8.7% in the right lens and 19.1 ± 9.8% in the left lens. This study shows that, on average, ~25% of patients' total lens dose was contributed by C-arm CBCT.

Magnetic Resonance Angiography-based Prediction of the Results of Balloon Test Occlusion

Precautious balloon test occlusion (BTO) is sometimes performed in cases of high-risk intraoperative internal carotid artery injury. We investigated whether magnetic resonance angiography (MRA) findings could predict BTO results to thus avoid the use of precautious BTO. This retrospective study, included 96 patients who underwent BTO, eight of whom underwent bilateral BTO. The relationship between the BTO results for 104 internal carotid arteries and the MRA findings obtained in 96 patients were retrospectively evaluated. On MRA, anterior cerebral artery (A1)–anterior communicating artery–A1 was defined as anterior collateral circulation (ACC), and posterior cerebral artery–posterior communicating artery was defined as posterior collateral circulation (PCC). BTO was tolerated in all 27 sides with thick ACC regardless of PCC thickness. In 31 of 44 cases with a thin ACC, the tested sides were BTO-tolerant (70.5%). Of these 44 tested sides, all five with a thick PCC were BTO-tolerant, but eight with a thin PCC and 31 with an invisible PCC showed results other than tolerance. Among cases with an invisible ACC, 10 of 33 tested sides were BTO-tolerant (30.3%). Among these 33 tested sides, outcomes other than tolerance were observed regardless of PCC thickness. Thick, thin, and invisible ACCs were assigned 3, 1, and 0 points, respectively; and thick, thin, and invisible PCCs were assigned 2, 1, and 0 points, respectively. A sum of 3 points in the ACC and PCC indicated that all sides were BTO-tolerant. In conclusion, a thick ACC or a thin ACC with a thick PCC indicates BTO-tolerance. The BTO prediction score is useful for predicting results of BTO.

Treatment Outcomes of Cerebral Aneurysms Presenting with Optic Neuropathy: A Retrospective Case Series

Background:

Optic neuropathy due to an aneurysm is relatively rare, with only a few small case series on this topic, and no randomized trials having been published until now. As such, the functional prognosis and treatment for aneurysm-induced optic neuropathy remain controversial.

Objective:

We quantified optic nerve injuries using an objective index (the visual impairment score) and evaluated prognostic factors of postoperative visual function.

Materials and Methods:

Of 960 patients treated for an unruptured intracranial aneurysm, 18 (1.9%) patients had optic neuropathy. Visual acuity and visual field were assessed before surgery and 6 months’ postoperatively. Cases were classified on the basis of treatment modality (coil embolization or flow alteration [FA]) and prognostic factors of the two treatment groups.

Results:

Of the 18 patients with an intracranial aneurysm and optic neuropathy, 12 (67%) were treated using coil embolization and 6 (33%) were FA. Visual function improved after surgery in 8 patients (44%), 5 (42%) in the coil embolization group, and 3 (50%) in the FA group. The visual function remained stable after surgery in 6 (33%) patients and worsened in 4 (22%). Patients with an aneurysms <15 mm in size had a favorable outcome (P = 0.05).

Conclusions:

Surgical treatment improved vision in 44% of cases, with no difference in the prognosis of coil embolization and FA and no effect of the duration of symptoms on outcomes. Further, the prognosis of visual function recovery was better for aneurysms <15 mm in diameter.

Impact of Endovascular Therapy in Patients With Large Ischemic Core

Background and Purpose—

Endovascular therapy (EVT) is strongly recommended for acute cerebral large vessel occlusion with the Alberta Stroke Program Early CT Score (ASPECTS) ≥6 due to occlusion of the internal carotid artery or M1 segment of the middle cerebral artery. However, the effect of EVT for patients who have ischemic core with ASPECTS ≤5 (0–5) was not established. The purpose of this study was to elucidate the outcomes of EVT for patients with large ischemic core.

Methods—

Based on the data of The Recovery by Endovascular Salvage for Cerebral Ultra-Acute Embolism Japan Registry 2, patients with internal carotid artery or M1 segment of the middle cerebral artery occlusion and pretreatment ASPECTS 0 to 5 on noncontrast CT or diffusion-weighted image were extracted, and the outcomes by EVT were analyzed. Primary end point was defined as a good functional outcome (modified Rankin Scale score of ≤2) after 90 days.

Result—

Among 2420 registered patients, 504 patients were with internal carotid artery or M1 segment of the middle cerebral artery occlusion and ASPECTS 0 to 5. Among these 504 patients, 172 (34.1 %) were treated with EVT (EVT group) and 332 (65.9 %) without (no-EVT group). In the no-EVT group, elderly patients, females, poor prestroke modified Rankin Scale, high National Institutes of Health Stroke Scale, low ASPECTS, and late admission were significantly more observed. Good functional outcomes were significantly more observed in the EVT group than in the no-EVT group (19.8 % versus 4.2 %; P <0.0001; adjusted odds ratio, 2.33; 95% CI, 1.10–4.94). The incidences of symptomatic intracranial hemorrhage within 72 hours did not significantly different between the EVT group and the no-EVT group (3.7 % versus 4.9%; P =0.55; adjusted odds ratio, 0.50; 95% CI, 0.14–1.73).

Conclusions—

Although outcomes in this group of patients were usually poor, the data suggested EVT may increase the likelihood of a good functional outcome.

The Visualization Methods of Occluded Dural Sinus for Safe Transvenous Embolization of Dural AVFs

BACKGROUND

Transvenous embolization (TVE) via occluded sinus is one option for the treatment of dural arteriovenous fistulas. Understanding of the anatomical characteristics of the occluded sinus is difficult. It is often hard to reach the shunt point because of some risk of vessel perforation.

METHODS

We assessed usefulness of T1 Volumetric Isotropic TSE Acquisition (VISTA) Black Blood (BB) and 3D-T1 Fast Field Echo (FFE) for the evaluation and visualization of an occluded sinus. Evaluation of T1 VISTA BB and 3D-T1 FFE was performed preoperatively. TVE was performed via the occluded sinus while referring to the visualized reconstruction image.

RESULTS

Fourteen cases of TVE were performed between 2009 and 2015. The entire occluded sinus, including both thrombus and blood flow, was seen as the high-intensity region on 3D FFE T1 gadlinium (Gd). On the other hand, thrombus was seen as the iso- or high-intensity region and blood flow as the low-intensity region on T1 VISTA BB. The maximum intensity projection reconstruction image of 3D FFE T1Gd could visualize the whole occluded sinus and was useful for microcatheter maneuver. Total shunt obliteration was achieved in 13 cases (92.8%) except for one.

CONCLUSIONS

Magnetic resonance imaging evaluation of the occluded sinus using both T1 VISTA BB and 3D FFE T1Gd gives us valuable information of the occluded sinus regarding the development and the course of the occluded sinus, the length of the thrombotic occlusion, and leads to safer catheter maneuvers in TVE.

[Dissecting Internal Carotid Aneurysm Causing Epistaxis:A Case Report]

We report a rare case of a ruptured dissecting internal carotid aneurysm caused epistaxis without a history of trauma or infection. An 89-year-old woman experienced epistaxis and suffered from hemorrhagic shock at her previous hospital. Head computed tomography(CT)images revealed a ruptured internal carotid aneurysm protruding into the Onodi cell, the most posterior ethmoidal sinus, which extends superolaterally to the sphenoid sinus. Cerebral angiography demonstrated a multilobular-shaped dissecting aneurysm with a maximal diameter of 6.7mm at the cavernous portion of the internal carotid artery(ICA). Overlapping stenting was performed to prevent recanalization. However, a fatal subarachnoid hemorrhage occurred 2 days after the procedure due to the progression of the dissection to the intracranial ICA. The anatomical characteristics of the ethmoidal sinus could be associated with the occurrence of epistaxis. A ruptured small ICA aneurysm with an Onodi cell might cause epistaxis without a history of trauma or infection.

Spinal Cord Infarction in the Region of the Posterior Spinal Artery After Embolization for Vertebral Artery Dissection

BACKGROUND

Endovascular surgery for vertebral artery dissections (VADs) carries the risk of spinal cord infarction (SCI). Although SCI in the region of the anterior spinal artery (ASA) has been reported, SCI in the region of the posterior spinal artery (PSA) is rare.

OBJECTIVE

To investigate PSA infarction after endovascular surgery for VAD.

METHODS

Infarction in the region of the PSA after endovascular surgery for VADs carried out in consecutive 21 cases was investigated. The variables of aneurysmal location, status, intra-aneurysmal thrombosis, antithrombotic therapy, and endovascular procedure were investigated in relation to the occurrence of spinal cord or brain stem infarction.

RESULTS

Thirteen cases were unruptured aneurysms, and 8, ruptured aneurysms. The endovascular surgical method was internal trapping in 10 cases, stent-assisted coil embolization in 8 cases, and proximal occlusion (PO) in 3 cases. Periprocedural symptomatic infarction was detected in 4 of the 21 cases (19%): 3 SCIs and 1 lower medulla infarction, after 1 stent-assisted coil embolization and 3 PO. All 3 symptomatic SCIs were PSA infarction. On univariate analysis, the variables of posterior inferior cerebellar artery-involved-type, PO, and intraprocedural proximal flow arrest were significantly correlated with occurrence of PSA infarction.

CONCLUSION

PSA infarction after endovascular surgery for VAD seems not to be a rare potential complication. Insufficiency of collateral blood flow and artery-to-artery embolism due to intraprocedural flow stagnation of the VA seem to be the possible mechanisms of PSA infarction in addition to previously reported mechanisms such as direct obliteration by the embolic materials and extended thrombosis of the VA stump.

Abstract WMP119: Neurovascular Unit Protection Using Nitroxide Radicals-containing Nanoparticles (TEMPO-RNP) for Cerebral Ischemia-reperfusion Injury in Mice

Purpose: Reperfusion injury after thrombolytic therapy or mechanical thrombectomy would adverse neurological outcome. Generation of reactive oxygen species (ROS) due to reperfusion is relevant for aggravation. The development of drug therapy for scavenging free radical is expected to lead to better neurological prognosis. We developed a new core-shell type nanoparticle, RNP (radical containing nanoparticle), which consists of micelle containing 4-amino-TEMPO. The purpose of this study is to evaluate an efficacy of intra-arterial injection of RNP after reperfusion using tMCAO mice model.

Methods: C57BL/6J mice underwent tMCAO for 60 minutes and received RNP by intra-arterial injection from common carotid artery. We evaluated infarction size, neurological scale, and Evans blue extravasation at 24h after reperfusion. RNP distribution was detected by rhodamine labeling. We further examined immunofluorescense of CD31, Occludin, TUNEL, dihydroethydium, and 8-hydroxy-deoxyguanosine (8-OHdG). Multiple free radical scavenging capacity of ischemic hemisphere was analyzed by Electron Paramagnetic Resonance (EPR).

Results: RNPs were detected in endothelial cells and around neuronal cells in the ischemic lesion. The infarction size, neurological scale, Evans blue extravasation of the mice treated by RNP were significantly lower than the mice treated by PBS , control group. Intra-arterial RNP treatment preserved endothelium and expression of occludin in the ischemic brain. Further, apoptosis of neuronal cells and production of superoxide anions and 8OHdG were suppressed. By using EPR, multiple ROS scavenging capacity (•OH, •ROO, •O 2 - ) of the ischemic brain treated by RNP were higher.

Conclusions: These results suggest that intra-arterial injection of RNP have efficacy of neurovascular unit protection and reduce infarction volume by improving multiple ROS scavenging capacity.

Early retreatment after surgical clipping of ruptured intracranial aneurysms

BACKGROUND

Although a rerupture after surgical clipping of ruptured intracranial aneurysms is rare, it is associated with high morbidity and mortality. The causes for retreatment and rupture after surgical clipping are not clearly defined.

METHODS

From a prospectively maintained database of 244 patients who had undergone surgical clipping of ruptured intracranial aneurysms, we selected patients who experienced retreatment or rerupture within 30 days after surgical clipping. Aneurysm occlusions were examined by microvascular Doppler ultrasonography and indocyanine green video-angiography. Indications for retreatment included rerupture and partial occlusion. We analyzed the characteristics and causes of early retreatment.

RESULTS

Six patients (2.5%, 95% CI 0.9 to 5.3%) were retreated within 30 days after surgical clipping, including two patients (0.8%, 95% CI 0.1 to 2.9%) who experienced a rerupture. The retreated aneurysms were found in the anterior communicating artery (AcomA) (n = 5) and basilar artery (n = 1). Retreatment of the AcomA (7.5%) was performed significantly more frequently than that of other arteries (0.56%) (p < 0.01). A laterally projected AcomA aneurysm (17.4%) was more frequently retreated than were other aneurysm types (2.3%). Cases of laterally projecting AcomA aneurysms tended to result from an incomplete clip placed using a pterional approach from the opposite side of the aneurysm projection.

CONCLUSIONS

Despite developments, the rates of retreatment and rerupture after surgical clipping remain similar to those reported previously. Retreatment of the AcomA was significantly more frequent than was retreatment of other arteries. Patients underwent retreatment more frequently when they were originally treated for lateral type aneurysms using a pterional approach from the opposite side of the aneurysm projection. The treatment method and evaluation modalities should be considered carefully for AcomA aneurysms in particular.

Neurovascular Unit Protection From Cerebral Ischemia-Reperfusion Injury by Radical-Containing Nanoparticles in Mice

BACKGROUND AND PURPOSE

Reperfusion therapy by mechanical thrombectomy is used to treat acute ischemic stroke. However, reactive oxygen species generation after reperfusion therapy causes cerebral ischemia-reperfusion injury, which aggravates cerebral infarction. There is limited evidence for clinical efficacy in stroke for antioxidants. Here, we developed a novel core-shell type nanoparticle containing 4-amino-4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (nitroxide radical-containing nanoparticles [RNPs]) and investigated its ability to scavenge reactive oxygen species and confer neuroprotection.

METHODS

C57BL/6J mice underwent transient middle cerebral artery occlusion and then received RNPs (9 mg/kg) through the common carotid artery. Infarction size, neurological scale, and blood-brain barrier damage were visualized by Evans blue extravasation 24 hours after reperfusion. RNP distribution was detected by rhodamine labeling. Blood-brain barrier damage, neuronal apoptosis, and oxidative neuronal cell damage were evaluated in ischemic brains. Multiple free radical-scavenging capacities were analyzed by an electron paramagnetic resonance-based method.

RESULTS

RNPs were detected in endothelial cells and around neuronal cells in the ischemic lesion. Infarction size, neurological scale, and Evans blue extravasation were significantly lower after RNP treatment. RNP treatment preserved the endothelium and endothelial tight junctions in the ischemic brain; neuronal apoptosis, O₂^- production, and gene oxidation were significantly suppressed. Reactive oxygen species scavenging capacities against OH, ROO, and O₂^- improved by RNP treatment.

CONCLUSIONS

An intra-arterial RNP injection after cerebral ischemia-reperfusion injury reduced blood-brain barrier damage and infarction volume by improving multiple reactive oxygen species scavenging capacities. Therefore, RNPs can provide neurovascular unit protection.

[Dural Arteriovenous Fistula with Acute Visual Loss Manifestation:A Case Report]

In this report, we are describing a rare case of dural arteriovenous fistula(DAVF)followed by an isolated symptom of bilateral visual acuity disturbance. The patient was a 67-year-old man suffering from progressive bilateral visual acuity disturbance. Angiography revealed a diffuse arteriovenous fistula in the left transverse-sigmoid sinus affected by severe venous congestion. Visual acuity disturbance is likely to have been caused by increased intracranial pressure(IICP). Venous congestion as well as visual acuity were gradually improved following three transarterial embolizations. It is possible that a gradual progression of the clinical condition has caused only visual acuity disturbance without any other IICP symptoms, which is similar to pseudotumor cerebri. Should an unexplained visual acuity loss occur, the case should be investigated by considering DAVF.

Sodium Bicarbonate Facilitates Hemostasis in the Presence of Cerebrospinal Fluid Through Amplification of Platelet Aggregation

BACKGROUND

Appropriate hemostasis is essential for clear visualization of the neural structures and cleavage planes. It is also essential for avoiding heat-induced injury, minimizing blood loss, and reducing operative time.

OBJECTIVE

To determine the role of cerebrospinal fluid (CSF) in platelet-dependent hemostasis during neurosurgery.

METHODS

The amplification of aggregation, activation of integrin αIIbβ3, intrinsic and extrinsic coagulation pathways, and activation of signaling cascades in platelets were evaluated. For comparison, various concentrations of a commercially available artificial CSF solution (aCSF), an artificial CSF solution prepared by the authors, and normal saline (NS) were used. Differences between aCSF and NS in obtaining in vivo hemostasis were assessed by measuring the tail vein bleeding time in C57BL/6N mice.

RESULTS

Platelet aggregation was directly amplified by the addition of aCSF through increased activation of integrin αIIbβ3, phosphatidylserine exposure, and P-selectin expression. However, the prothrombin time and activated partial thromboplastin time were not primarily related to coagulation activity with the addition of aCSF. Activation of Src kinase was related to platelet activation by aCSF. The elimination of sodium bicarbonate from aCSF and the addition of the selective inhibitor of the HCO3/Cl exchanger, 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid disodium salt, significantly inhibited platelet aggregation. The bleeding time in aCSF-treated mice was significantly shorter than that in NS-treated mice.

CONCLUSION

Sodium bicarbonate facilitates hemostasis through the amplification of platelet aggregation function. The existence of CSF and irrigation with aCSF provide better conditions for physiological hemostasis and they have the potential of improving hemostasis by bipolar coagulation or with irrigation during neuroendoscopic procedures.

Photodynamic Diagnosis Using 5-Aminolevulinic Acid in 41 Biopsies for Primary Central Nervous System Lymphoma

We evaluated the feasibility of 5-aminolevulinic acid (5-ALA)-mediated photodynamic diagnosis (PDD) in the biopsy for primary central nervous system lymphoma (PCNSL). 5-ALA (20 mg kg(-1) ) was administered orally 4 hours preoperatively. Forty-one biopsies obtained under PDD in 47 consecutive biopsies (46 patients) that were finally pathologically diagnosed as PCNSL were evaluated. Positive fluorescence was observed in 34 of those 41 biopsies (82.9%). An intraoperative pathological diagnosis (IOD) of suspected PCNSL was made in 21 of the biopsies with positive fluorescence (61.8%). However, the eight IODs in the remaining 13 biopsies (23.5%) were not correct (atypical cell, 4; high-grade glioma, 1; gliosis, 1; unremarkable, 2). In those 8 biopsies, PCNSL was confirmed by the final pathological diagnosis. There was no difference in the mean Mib-1 labeling index between the biopsies with positive fluorescence (86.5%) and those without positive fluorescence (90.0%). IOD was not performed in 6 biopsies; however, 5 of those biopsies (83.3%) showed positive fluorescence and were finally pathologically diagnosed as PCNSL. Use of PDD in biopsies for patients with suspected PCNSL is a reliable way of obtaining specimens of adequate quality for the final pathological diagnosis and may lead to improved diagnostic yield in the biopsy of PCNSL.

[A Case of Traumatic Carotid Cavernous Fistula Treated with a Single Procedure Selective Transarterial Embolization Using Hydrogel Coils]

A 30-year-old man was admitted to our hospital after a bicycle accident. Proptosis, conjunctival congestion, and orbital vascular bruit appeared one month after the accident. Neuroradiological findings showed a traumatic carotid cavernous fistula(CCF). CCF is a pathologic arteriovenous shunt between the carotid artery and cavernous sinus. A detachable balloon was the standard device used for treatment of high flow direct CCF, although it is currently unavailable in Japan. Therefore, many other constructive strategies are being developed. We successfully treated this patient with single transarterial embolization using hydrogel coils. Hydrogel coils are platinum coils coated with polymeric water gels, and can be used at a prospect of delayed volume expansion. In our case, the patency of the internal carotid artery was maintained using the coils, and the symptoms improved shortly after the procedure. The use of hydrogel coils for the treatment of CCF appears to be safe and effective.

Anatomical risk factors for ischemic lesions associated with carotid artery stenting

The purpose of this study was to investigate the anatomical risk factors for ischemic lesions detected by diffusion-weighted imaging (DWI) associated with carotid artery stenting (CAS). DWI was performed within four days after CAS in 50 stenotic lesions between January 2008 and September 2013. We retrospectively analyzed the correlation between the anatomical factors and ischemic lesions associated with CAS. Post-procedural DWI revealed new ischemic lesions after 24 (48%) of the 50 CAS procedures. All three patients with common carotid artery tortuosity, defined as the presence of severe angulation (less than 90 degrees) in the common carotid artery, developed new ischemic lesions. However, there were no significant differences between the patients with and without tortuosity, likely due to the small number of cases. Meanwhile, seven of eight patients with internal carotid artery tortuosity, defined as the presence of severe angulation (less than 90 degrees) in the cervical segment of the internal carotid artery, developed new ischemic lesions. A multivariate analysis showed internal carotid artery tortuosity (odds ratio: 11.84, 95% confidence interval: 1.193-117.4, P= 0.035) to be an independent risk factor for the development of ischemic lesions associated with CAS. Anatomical factors, particularly severe angulation of the internal carotid artery, have an impact on the risk of CAS. The indications for CAS should be carefully evaluated in patients with these factors.

Analysis of closed-cell intracranial stent characteristics using cone-beam computed tomography with contrast material

The intracranial nitinol stent named the Enterprise Vascular Reconstruction Device has poor radiographic visibility. The characteristics of closed-cell intracranial stents were investigated and the efficacy of intraoperative stent visualization examined with the 80 kV high-resolution XperCT protocol, which is a flat detector C-arm volume acquisition functionality system integrated with the angiography equipment. We treated 39 aneurysms with stent-assisted coil embolization. The aneurysms were located on the internal carotid artery in 24 cases, the anterior communicating artery (AcomA) in three, the basilar artery (BA) in 10, and the vertebral artery in two. Intraoperative 80 kV XperCT was performed in all cases after deposition of the stent. We evaluated the coverage of the aneurysm neck, incomplete stent apposition (ISA), and shift of vessels. Accurate stent visualization was achieved in 29 of the 39 cases without coil and delivery wire artifact. Coverage of the aneurysm neck succeeded in 28 cases; there was one case of BA top Y-configuration stenting in which the stent was dislocated into the aneurysm. ISA was detected in nine cases, including seven kinks and one flattening in the carotid siphon and one kink in the BA top. We detected linearization of vessels due to stent deployment in three AcomA cases and three BA top cases. We conclude that intraoperative 80 kV XperCT is an efficient modality for the evaluation of ISA. Stent kinking in the carotid siphon and linearization in distal vessels can be detected with this protocol.

Endovascular Treatment of Spinal Vascular Lesion in Japan: Japanese Registry of Neuroendovascular Therapy (JR-NET) and JR-NET2

A subgroup analysis of spinal vascular lesions in the Japanese Registry of Neuroendovascular Therapy (JR-NET) and JR-NET2, retrospective registry studies conducted in 2005–2009, was performed to understand the current status of treatment in Japan. Of 201 spinal lesions enrolled, 98 analyzable cases of spinal dural arteriovenous fistula (SDAVF), 43 of spinal perimedullary arteriovenous fistula (SPAVF), and 23 of spinal intramedullary arteriovenous malformation (SIAVM) were assessed. Treatment was radical in the majority (83.6%) of SDAVF, palliative in the majority (70.6%) of SIAVM, and radical and palliative in a similar number of cases of SPAVF. Total occlusion was achieved in 26 (54.2%) SDAVF cases, 9 (29.0%) SPAVF, and 4 (23.5%) SIAVM. Treatment-related complications occurred in 3 (3.1%) SDAVF cases, 7 (16.3%) SPAVF, and 1 (4.3%) SIAVM. Post-treatment neurological improvement was achieved in 49 (50.0%) of SDAVF cases, 15 (34.9%) SPAVF, and 5 (21.7%) SIAVM. The modified Rankin Scale (mRS) of 0, 1, or 2 on postoperative day 30, the primary endpoint, was achieved in 62 (63.3%) SDAVF cases, 26 (60.5%) SPAVF, and 12 (52.2%) SIAVM. The mRS of 0–2 on postoperative day 30 was correlated with presymptomatic mRS of 0–2 [P<0.0001, odds ratio (OR): 42.88, 95% confidence interval (CI): 14.83–123.97] and postoperative neurological improvement (P=0.046, OR: 2.57, 95% CI: 1.02–6.48). In Japan, endovascular treatment of spinal vascular lesions was administered safely. Good mRS on postoperative day 30 was highly correlated with good pre-symptomatic mRS, suggesting necessity of early diagnosis and treatment.

Endovascular treatment of spinal vascular lesion in Japan: Japanese Registry of Neuroendovascular Therapy (JR-NET) and JR-NET2

A subgroup analysis of spinal vascular lesions in the Japanese Registry of Neuroendovascular Therapy (JR-NET) and JR-NET2, retrospective registry studies conducted in 2005–2009, was performed to understand the current status of treatment in Japan. Of 201 spinal lesions enrolled, 98 analyzable cases of spinal dural arteriovenous fistula (SDAVF), 43 of spinal perimedullary arteriovenous fistula (SPAVF), and 23 of spinal intramedullary arteriovenous malformation (SIAVM) were assessed. Treatment was radical in the majority (83.6%) of SDAVF, palliative in the majority (70.6%) of SIAVM, and radical and palliative in a similar number of cases of SPAVF. Total occlusion was achieved in 26 (54.2%) SDAVF cases, 9 (29.0%) SPAVF, and 4 (23.5%) SIAVM. Treatment-related complications occurred in 3 (3.1%) SDAVF cases, 7 (16.3%) SPAVF, and 1 (4.3%) SIAVM. Post-treatment neurological improvement was achieved in 49 (50.0%) of SDAVF cases, 15 (34.9%) SPAVF, and 5 (21.7%) SIAVM. The modified Rankin Scale (mRS) of 0, 1, or 2 on postoperative day 30, the primary endpoint, was achieved in 62 (63.3%) SDAVF cases, 26 (60.5%) SPAVF, and 12 (52.2%) SIAVM. The mRS of 0–2 on postoperative day 30 was correlated with pre-symptomatic mRS of 0–2 [P < 0.0001, odds ratio (OR): 42.88, 95% confidence interval (CI): 14.83–123.97] and postoperative neurological improvement (P = 0.046, OR: 2.57, 95% CI: 1.02–6.48). In Japan, endovascular treatment of spinal vascular lesions was administered safely. Good mRS on postoperative day 30 was highly correlated with good pre-symptomatic mRS, suggesting necessity of early diagnosis and treatment.