Japanese Registry Of Neuroendovascular Therapy Research Articles

Early neurological changes following endovascular therapy for acute stroke due to intracranial atherosclerotic disease

BackgroundEndovascular therapy (EVT) reduces functional disability in patients with acute large vessel occlusion (LVO). However, the early neurological change after EVT may be limited in patients with intracranial atherosclerotic disease (ICAD). MethodsWe analyzed the Japanese Registry of NeuroEndovascular Therapy (JR-NET) 4 which was a retrospective, nationwide, multicenter registry of patients with LVO between 2015 and 2019. We compared the early neurological change, efficacy and safety of EVT for acute LVO in ICAD and other etiologies. The primary outcome was NIHSS improvement ≥10 points, and secondary outcome were NIHSS worsening ≥4 points 7 days after EVT, effective reperfusion rate, 30-day functional outcomes, and safety outcomes. ResultsAmong the 6710 enrolled patients, 610 (9.1%) had ICAD. The ICAD group was younger (mean 72.0 vs. 75.8 years) and predominantly male (63.4% vs. 56.0%), had lower NIHSS scores before EVT (median 16 vs. 18), and underwent percutaneous transluminal angioplasty and stenting more frequently (43.0% vs. 4.4%, 12.3% vs. 4.4%). In the ICAD group, NIHSS improvement was significantly lower (adjusted odds ratio (aOR) [95% confidence interval (95%CI)] 0.52 [0.41–0.65]), NIHSS worsening was significantly higher (aOR [95%CI] 1.76 [1.31–2.34]), and effective reperfusion was significantly lower (aOR [95%CI] 0.47 [0.36–0.60]). Fewer patients with ICAD had modified Rankin scale 0–2 at 30 days (aOR [95%CI] 0.60 [0.47–0.77]). The risk of acute reocclusion was more prominent in the ICAD group (aOR [95%CI] 4.03 [1.98–8.21]). ConclusionsImprovement in neurological severity after EVT was lower in patients with LVO and ICAD.

Real-world Data of Antithrombotic Therapy in Neuroendovascular Therapy: Analysis of JR-NET 4.

As the number of neuroendovascular therapies in Japan increases, the current trends in periprocedural antithrombotic therapy must be understood.We retrospectively analyzed data on periprocedural antithrombotic therapy in the Japanese Registry of Neuroendovascular Therapy (JR-NET) 4, a nationwide survey carried out in Japan between January 2015 and December 2019. Details on antithrombotic therapy in neuroendovascular therapy for ruptured cerebral aneurysms, unruptured cerebral aneurysms, and percutaneous transluminal angioplasty or stenting were collected from the JR-NET 4 database. These data were analyzed and compared with those from the JR-NET 2 (January 2008 to December 2009) and JR-NET 3 (January 2010 to December 2014). A total of 36,560 cases were analyzed in the JR-NET 4. The frequency of preprocedural dual antiplatelet therapy (DAPT) significantly increased from the JR-NET 2 to 4 (48.1%, 53.4%, and 62.3%, respectively; P < 0.001), whereas the frequency of monotherapy significantly decreased (15.7%, 13.9%, and 8%, respectively; P < 0.001). Postprocedural antiplatelet therapy exhibited similar trends, and postprocedural anticoagulant therapy was discontinued. Particularly, heparin use significantly decreased from the JR-NET 2 to 4 (23.4% vs. 12.7% vs. 7.9%, respectively; P < 0.001). In terms of periprocedural complications, the incidence of ischemic complications increased from the JR-NET 3 to 4 (5.8% vs. 6.2%; P = 0.05). In the JR-NET 4, severe adverse events and hemorrhagic and all complications were significantly more frequent in the preprocedural triple or more therapy group.The rate of postprocedural anticoagulant therapy decreased, whereas that of antiplatelet therapy increased. Overall, in Japan, periprocedural DAPT has become increasingly common.

Trends and Progress in Neuroendovascular Treatment in Japan: Japanese Registry of Neuroendovascular Therapy (JR-NET) 4. Main Report.

We reported the main results of the Japanese Registry of Neuroendovascular Therapy (JR-NET) 4, a nationwide surveillance of therapy (NET) in Japan from January 2015 to December 2019. JR-NET 4 registered consecutive patients who underwent NETs by Japan Society of Neuroendovascular Therapy (JSNET) -certified specialists. The primary endpoint was functional independence (mRS score of 0-2) at 30 days post-NET, with secondary endpoints focusing on technical success and major adverse events within 30 days.A total of 63,230 patients and 60,354 NET procedures from 166 participating centers were analyzed. During the study period, NET cases have consistently increased, with an increase in the proportion of elderly patients. A significant trend shift was observed in the distribution of NET procedures, with endovascular treatment for acute ischemic stroke that showed a dramatic increase in 5 years. This trend aligns with key randomized clinical trials from 2015 that presented the efficacy of this treatment. Clinical outcomes at 30 days posttreatment revealed that endovascular treatment for acute ischemic stroke and other NETs maintained safety and effectiveness despite varying prevalence of functional independence between target diseases. The study also observed a steady increase in emergency treatment cases, reflecting the increase in acute ischemic stroke, a time-sensitive medical condition.This comprehensive surveillance highlights the trend of NET practices in Japan, driven by clinical evidence and advancements in treatment devices. Although these findings were specific to Japan, they offer valuable insights into the broader trends in NETs and acute stroke care.

The Current Status of Endovascular Treatment for Extracranial Vertebral Artery Stenosis in Japan: A Subanalysis of the Japanese Registry of Neuroendovascular Therapy 4.

Endovascular treatment (EVT) is a potential therapeutic option for extracranial vertebral artery (VA) stenosis; however, its efficacy or optimal procedures remain unknown. This study aimed to investigate the recent status of EVT for extracranial VA stenosis in Japan using a nationwide registry. We conducted a post hoc analysis of the Japanese Registry of Neuroendovascular Therapy 4 that enrolled patients who underwent EVT at 166 hospitals in Japan from 2015 to 2019. The outcomes of this study were as follows: procedural success indicating that the planned procedure was completed, modified Rankin Scale (mRS) score at 30 days, and procedure-related complications evaluated according to the procedure during EVT (percutaneous transluminal angioplasty vs. stenting and with or without the use of embolic protection devices [EPDs]). Of 308 eligible patients, 301 (95%) were treated for atherosclerotic stenosis, predominantly by stenting (74%). EPDs were used in 43%, primarily with the distal balloon (63%). The proportion of procedural success was 98%. Functional independence (mRS of 0-2) at 30 days was achieved in 80% of the total cohort, and there were no differences between patients treated with or without stenting or EPDs (74% vs. 82%, p = 0.12, and 80% vs. 80%, p = 0.93). Procedural complications occurred in 28 (9.1%) patients similarly in each group, with distal embolism and vessel dissection being common. In conclusion, EVT is a reasonable option for extracranial VA stenosis as a daily clinical practice. This study emphasizes the potential of EVT in managing extracranial VA stenosis and the need for further research to refine treatment strategies.

Factors related to adverse events during endovascular coil embolization for ruptured cerebral aneurysms

Background and purposeThe risk factors for adverse events for example, intraprocedural rupture (IPR), ischemic complication within 24 hours, and rebleeding after endovascular coil embolization for a ruptured cerebral aneurysm remain...

Coil Embolization for Unruptured Intracranial Aneurysms at the Dawn of Stent Era: Results of the Japanese Registry of Neuroendovascular Therapy (JR-NET) 3

Endosaccular coiling is recognized as a feasible method for treating unruptured intracranial aneurysms (UIAs). We retrospectively reviewed cases of UIAs treated by coiling in the Japanese Registry of Neuroendovascular Therapy (JR-NET) 3, a nationwide survey of NET between 2010 and 2014, the beginning period of intracranial stents in Japan. Data were extracted for 6844 UIAs (6619 procedures) from 40,169 registered records of all NETs in the JR-NET 3 databases. The features of the aneurysms and procedures, immediate radiographic findings, procedure-related complications, and clinical outcomes at 30 days after the procedures were assessed. Of 6844 UIAs, 81.8% were located in the anterior circulation. The mean patient age was 61.3 years (72.4% females). Compared with the preceding JR-NET 1 and 2, there were significant increases (P <0.05) in the rates of the following in JR-NET 3: wide-necked and small UIAs measuring <10 mm (from 56.4% to 58.8%), adjunctive techniques (54.8% to 71.8%), and stent usage (1.1% to 22.1%). Both pre- (85.6% to 96.7%) and post-procedural (84.0% to 94.6%) antiplatelet therapy were more frequently administered in JR-NET 3. Although procedure-related complication rates did not differ between the two groups, ischemic complication rates increased from 4.6% to 5.9%, leading to an increase in the 30-day morbidity (modified Rankin Scale >2) from 2.1% to 2.8%. In conclusion, introduction of neck-bridge stent was associated with an increase in cases of wide-necked aneurysms. However, the ischemic complication rate increased despite the greater use of periprocedural antiplatelet therapy.

Endovascular Therapy for Intracranial Artery Stenosis: Results from the Japanese Registry of Neuroendovascular Therapy (JR-NET)3.

A total of 907 patients enrolled in the Japanese Registry of Neuroendovascular Therapy (JR-NET)3, a surveillance study in Japan, who underwent intracranial percutaneous transluminal angioplasty (PTA)/stenting for intracranial stenosis during the period from 2010 to 2014 were investigated. Technical success was achieved in 97.5% of the patients, and 6.8% had a residual stenosis of ≥50%. The incidence rates of ischemic and hemorrhagic complications were as low as 5.3% and 3.1%, respectively, and the mortality rate was 1.9%. However, the mortality rate of cases with either complications was higher at 10.7%. About half of the treatment cases were performed between 24 h and 14 days after onset, and the incidence of perioperative complications was similar to that after at least 15 days. Although it is necessary to verify the effectiveness of PTA/stenting within 14 days, the results of this treatment were stable regardless of the intervention period.

Trends in Endovascular Reperfusion Therapy for Acute Stroke after Introduction of Mechanical Thrombectomy Devices: Japanese Registry of NeuroEndovascular Therapy (JR-NET)3.

In Japan, the era of thrombectomy for acute stroke started when the Merci retriever was approved in 2010 and the Penumbra system in 2011. New-generation Penumbra catheters (MAX series) and stent retrievers were introduced in 2013 and 2014, respectively. The aim of this study was to clarify the general status and trends in endovascular reperfusion therapy for stroke in Japan from 2010 to 2014. We extracted a total of 3705 patients (72.1 ± 12.2 years, 1482 women) from a nationwide study of patients receiving any neuroendovascular treatment, the Japanese Registry of NeuroEndovascular Therapy 3. Reperfusion therapy resulted in a successful reperfusion rate of 59%, and 31% of patients achieved a favorable outcome at 30 days of onset. The frequency of Merci-including procedures increased to 52% in the first half of 2011, but conversely decreased to 1% in the second half of 2014. The frequency of Penumbra-including procedures increased from 18% in the second half of 2011 to 67% in the first half of 2014, decreasing to 38% in the second half of 2014. The reperfusion rate and 30-day clinical outcomes remained almost unchanged until June 2013, and started to improve thereafter, coincident with the introduction and spread of newer-generation devices. The rate of successful reperfusion reached 71–76%, and 36–38% of patients achieved a favorable outcome in 2014. After multivariate adjustment for preprocedure variables, the calendar period from 2013 to 2014 was significantly associated with improvement in reperfusion rates and clinical outcomes.

Analysis of Puncture Site-related Complications in Japanese Registry of Neuroendovascular Therapy (JR-NET)3.

A subgroup analysis of puncture site-related complications listed in the Japanese Registry of NeuroEndovascular Therapy 3, based on retrospective studies, was performed. Puncture site-related complications occurred in 315 (0.73%, average age: 65.2) of 36,708 patients out of all 43,303 registered cases. Carotid artery stenting (CAS, 95 patients, 1.1%, P <0.01) and extracranial percutaneous transluminal angioplasty (PTA, 21 patients, 1.4%, P <0.01) were associated with significantly higher incidence of puncture site-related complications. The incidence of complications correlated with the number of antiplatelet drugs (P <0.001). Although 40% of the puncture complications were treated conservatively, 13% were treated endovascularly and 5% underwent open surgery.

Results of 1940 embolizations for dural arteriovenous fistulas: Japanese Registry of Neuroendovascular Therapy (JR-NET3).

Embolization is the most common treatment for dural arteriovenous fistulas (dAVFs). A retrospective, multicenter observational study was conducted in Japan to clarify the nature, frequency, and risk factors for complications of dAVF embolization. Patient data were derived from the Japanese Registry of Neuroendovascular Therapy 3 (JR-NET3). A total of 40,169 procedures were registered in JR-NET3, including 2121 procedures (5.28%) in which dAVFs were treated with embolization. After data extraction, the authors analyzed complication details and risk factors in 1940 procedures performed in 1458 patients with cranial dAVFs treated with successful or attempted embolization. Transarterial embolization (TAE) alone was performed in 858 cases (44%), and transvenous embolization (TVE) alone was performed in 910 cases (47%). Both TAE and TVE were performed in one session in 172 cases (9%). Complications occurred in 149 cases (7.7%). Thirty-day morbidity and mortality occurred in 55 cases (2.8%) and 16 cases (0.8%), respectively. Non-sinus-type locations, radical embolization as the strategy, procedure done at a hospital that performed dAVF embolization in fewer than 10 cases during the study period, and emergency procedures were independent risk factors for overall complications. Complication rates of dAVF embolization in Japan were acceptable. For better results, the risk factors identified in this study should be considered in treatment decisions.

Changing Paradigms of Periprocedural Antithrombotic Therapy in Neuroendovascular Therapy: Analysis of JR-NET 3.

To evaluate the changing paradigms of periprocedural antithrombotic management in neuroendovascular therapy in Japan, we analyzed the details of the current periprocedural antithrombotic therapy and compared it with those of the previous generations. We retrospectively analyzed the data from the Japanese Registry of Neuroendovascular Therapy (JR-NET) 3, a nationwide survey in Japan for neuroendovascular therapy between January 2010 and December 2014. A total of 26,233 patients underwent endovascular treatments to usually perform periprocedural antithrombotic therapy were retrospectively analyzed. We compared the results of JR-NET 3 with those of JR-NET 1 (January 2005 and December 2007) and JR-NET 2 (January 2008–December 2009). Post-procedural anticoagulant therapy was less utilized in JR-NET 3 than in JR-NET 2 (53.9% vs. 60.6%, P <0.001). Pre-procedural antiplatelet therapy became more frequent and more intensive with each generation. The frequency of aggressive therapy (dual, and triple or more therapy) was 65.2% in JR-NET 3, which was significantly higher than that of JR-NET 1 and JR-NET 2 (41.5% and 61.2%, respectively, P <0.001). However, periprocedural ischemic complications (2.0% vs. 5.8%, P <0.001) significantly increased, despite aggressive antiplatelet therapy. Neuroendovascular periprocedural antithrombotic therapy is focused more on antiplatelet therapy than on anticoagulant therapy. Currently, antiplatelet therapy is more frequently used with a larger number of multiple agents, however, periprocedural ischemic complications significantly increased.

Safety and Feasibility of Neuroendovascular Therapy for Elderly Patients: Analysis of Japanese Registry of Neuroendovascular Therapy 3.

Japan has a rapidly aging population and the application of neuroendovascular therapy (NET) for cerebrovascular diseases among elderly patients has increased, but feasibility and safety of NET for elderly patients are still debated. Therefore, this study aimed to elucidate feasibility and safety of NET by analyzing the Japanese nationwide database, the Japanese Registry of Neuroendovascular Therapy 3 (JR-NET 3). In total, 35,972 patients in the JR-NET 3 were analyzed retrospectively. “Elderly patients” were defined as those aged ≥75 years. Approximately one-quarter of patients who received NET were elderly patients. The proportion of patients with modified Rankin Scale (mRS) 0–2 before treatment and 30 days after NET was significantly low across all diseases in the elderly patients. Technical success rates were generally high across all procedures, but complication rate was significantly higher among elderly patients; ischemic complications were significantly higher with NET for unruptured aneurysms (UA) and carotid artery stenosis (CAS). Multivariate analysis revealed that mRS 0–2 before treatment [odds ratio (OR): 0.56, 95% confidence interval (CI): 0.34–0.94, P = 0.03], middle cerebral artery aneurysm (OR: 0.33, 95% CI: 0.12–0.92, P = 0.04), and complete obliteration (OR: 0.66, 95% CI: 0.44–0.97, P = 0.03) were associated with ischemic complications with NET for UA. Moreover, mRS 0–2 before treatment (OR: 0.55, 95% CI: 0.36–0.86, P < 0.01), high intensity with time-of-flight magnetic resonance angiography (OR: 1.55, 95% CI: 1.03–2.32, P = 0.04), open-cell stent (OR: 2.20, 95% CI: 1.50–3.22, P <0.01) were associated with ischemic complications with NET for CAS. Taken together, our findings indicate that cautious and precise selection of patients suitable for NET is necessary.

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.

Treatment Outcome of Intracranial Tumor Embolization in Japan: Japanese Registry of NeuroEndovascular Therapy 3 (JR-NET3).

Embolization for intracranial tumor is performed as a standard endovascular treatment. A retrospective, multicenter, observational study was conducted to clarify the nature, frequency, and risk factors of complications in intracranial tumor embolization. Patients were derived from the Japanese Registry of NeuroEndovascular Therapy (JR-NET3) using data taken from January 2010 through December 2014 in Japan. A total of 40,169 patients were enrolled in JR-NET3, of which, 1,545 patients (3.85%) with intracranial tumors underwent embolization. The primary end point was the proportion of patients with a modified Rankin scale (mRS) score of 0–2 (independency) at 30 days after embolization. The secondary end point was the occurrence of complications related to the procedures. The risk factors of the development of complications were analyzed. The proportion of patients with mRS scores ≤2 at 30 days after procedure was 89.5%. Complications occurred in 57 of the 1544 patients (3.7%). Multivariate analysis showed that target vessels other than external carotid artery (ECA) (OR, 3.56; 95% CI, 2.03–6.25; P <0.001) and use of liquid material (OR, 2.65; 95% CI, 1.50–4.68; P <0.001) were significantly associated with the development of complications. In JR-NET3, the primary end point was 89.5%, and the procedure-related complication rate was 3.7%. Embolization from other than ECA was significant risk factor of the complications. In addition, increasing usage of liquid embolic material worsened the risk of complications.

Real-world Experience of Carotid Artery Stenting in Japan: Analysis of 8458 Cases from the JR-NET3 Nationwide Retrospective Multi-center Registries

We aimed to clarify the outcomes of carotid artery stenting (CAS) in the Japanese population. For this purpose, we reviewed data from the Japanese Registry of NeuroEndovascular Therapy 3 (JR-NET3), a retrospective, nation-wide, multi-center, observational study of neuroendovascular treatments in Japan. Of the 9207 patients who underwent CAS between January 2010 and December 2014, 8458 satisfied the inclusion criteria for our analysis. The outcome statistics of this JR-NET3 cohort were compared to those of JR-NET1 and 2 cohorts fitting the same inclusion criteria. Of the 8458 JR-NET3 patients analyzed, 8042 (95.1%) were treated by surgeons with board certification from the Japanese Society for NeuroEndovascular Therapy. Technical success was achieved in 8417 patients (99.5%), whereas 198 patients (2.3%) had clinically significant complications (CSCs). These findings mirrored those obtained for the JR-NET1 and 2 cohorts. On multivariate analysis, risk factors for CAS-associated CSC included symptomatic lesion [odds ratio (OR), 1.91; 95% confidence interval (CI), 1.23–3.00; P = 0.003] and hypoechoic lesion on carotid artery ultrasound (OR, 1.85; 95% CI, 1.21–2.84; P = 0.005), whereas use of closed-cell stents was a predictor of better outcome (OR, 0.53; 95% CI, 0.35–0.79; P = 0.002). The findings of JR-NET3 reflect good outcomes of CAS, but non-modifiable risk factors reflecting lesion characteristics remain of concern. Using closed-cell stents is advisable. Technological advances such as the introduction of new materials may help further improve CAS outcomes in Japanese patients.

Parent Artery Occlusion for Unruptured Cerebral Aneurysms: Results of the Japanese Registry of Neuroendovascular Therapy 3.

Although the current standard treatment for unruptured aneurysms comprises surgical clipping or endovascular coiling, these techniques are not suitable for some cases, such as large, giant, and fusiform aneurysms. Endovascular parent artery occlusion (PAO), which includes internal trapping and proximal occlusion, is a well-established alternative treatment for such cases. Here, we retrospectively reviewed PAO cases from the Japanese Registry of Neuroendovascular Therapy 3, a nation-wide survey of all neuroendovascular therapy cases between 2010 and 2014. This dataset included 274 procedures with a mean patient age of 57.1 years and 55.4% female patients. For the treatment strategy, internal trapping was selected in 213 aneurysm cases (77.7%) and proximal occlusion in 61 aneurysm cases (22.2%). Most of the procedures were successfully completed (272/274: 99.2%). Immediately after treatment, angiographical complete occlusion was achieved in 248 cases (90.5%). Although the feasibility of this technique was excellent, there were 60 periprocedural complications (21.8%), including 48 ischemic complications (17.5%), seven hemorrhagic complications (2.5%). Overall, morbidity and mortality at 30 days postoperative were 5.8% and 0.7%, respectively. Among the pretreatment variables, a patient age of 70 and older was associated with ischemic complications [odds ratio (OR); 2.34, 95% confidence interval (CI); 1.02–5.25; P = 0.04] and a small aneurysm size (<5 mm) was associated with hemorrhagic complications (OR; 9.85, 95% CI; 1.07–221.0; P = 0.04) by multivariate analysis. In conclusion, PAO for unruptured cerebral aneurysms is feasible, but is associated with a complication rate of approximately 20%. Various alternative treatment options should be carefully considered with deconstructive strategies.

Endovascular Treatment for Vasospasm after Aneurysmal Subarachnoid Hemorrhage Based on Data of JR-NET3.

Endovascular treatments for vasospasm after subarachnoid hemorrhage are typically performed for patients who are refractory to recommended medical therapies. We analyzed the current status of endovascular treatments based on the data of Japanese Registry of Neuroendovascular Therapy (JR-NET)3, and evaluated factors related to improvement of imaging findings and neurological condition, and to mechanical hemorrhage complications. We collected data of 1211 treatments performed from 2010 to 2014. Target vessels for treatments were anterior circulation (n = 1079), posterior circulation (n = 91), and both (n = 32); the distribution of vasospasm was the proximal vessel (n = 754) to the Circle of Willis, distal vessel (n = 329), and both (n = 119). Of the treatments, 948 cases (78.3%) were intra-arterial administration of vasodilators and 259 (21.4%) were percutaneous transluminal angioplasty (PTA); 879 cases were the first intervention. The treatment time from onset was within 3 h in 378 (31.2%) cases, between 3 and 6 h in 349 (28.8%) cases, and over 6 h in 245 (20.2%) cases. The statistically significant factors associated with improvement on imaging findings was the first treatment, and treatment within 3 h from onset compared with that after 6 h. Additionally, the first and early treatments after the symptoms were associated with significantly improved neurological condition. All complications of mechanical hemorrhage occurred along with PTA. The findings show that endovascular treatment for vasospasm was effective, especially for cases who suffered from symptomatic vasospasm with a short interval after onset.

CONTENTS

The present study retrospectively analyzed the database of the Japanese Registry of Neuroendovascular Therapy 1 and 2 (JR-NET1&2) to determine annual trends, including adverse events and clinical outcomes at 30 days after undergoing neuroendovascular therapy. JR-NET1&2 are surveys that targeted all patients in Japan who underwent neuroendovascular therapy delivered by physicians certified by the Japanese Society of Neuroendovascular Therapy (JSNET) between 2005 and 2009. Medical information about the patients was anonymized and retrospectively registered via a website. Data from 32,608 patients were analyzed. The number of treated patients constantly increased from 5,040 in 2005 to 7,406 in 2009 and the rate of octogenarians increased from 7.0% in 2005 to 10.4% in 2009. The proportion of procedures remained relatively constant, but ratios of angioplasty slightly increased from 32.8% in 2005 to 33.7% in 2009. Procedural complications were associated more frequently with acute stroke (9.6%), ruptured aneurysms (7.4%), intracranial artery disease (ICAD) (5.4%), and arteriovenous malformation (AVM, 5.2%). The number of patients requiring neuroendovascular treatment in Japan is increasing and the outcomes of such therapy are clinically acceptable. Details of each type of treatment will be investigated in sub-analyses of the database.

Endovascular Treatment for Ruptured Vertebral Artery Dissecting Aneurysms: Results from Japanese Registry of Neuroendovascular Therapy (JR-NET) 1 and 2

In treating ruptured vertebral artery dissecting aneurysms (VADAs), neuroendovascular therapy (NET) represented by coil obliteration is considered to be a reliable intervention. However, there has been no multi-center based study in this setting so far. In this article, results of NET for ruptured VADA obtained from Japanese Registry of Neuroendovascular Therapy (JR-NET) 1 and 2 were assessed to elucidate the factors associated with favorable outcome. A total of 213 in JR-NET1 and 381 patients in JR-NET2 with ruptured VADA were included, and they were separately analyzed because several important datasets such as vasospasm and site of dissecting aneurysms in relation to the posterior inferior cerebellar artery (PICA) were collected only in JR-NET1. The ratio of poor World Federation of Neurosurgical Societies (WFNS) grade (4 and 5) was 48.8% and 53.9%, and the ratio of favorable outcome (modified Rankin scale, mRS 0 to 2) at 30 days after onset was 61.1 % and 49.1% in JR-NET1 and 2, respectively. In both studies, poor WFNS grade and procedural complication were independently correlated as negative factors for favorable outcome. In JR-NET1, PICA-involved lesion was also designated as a negative factor while elderly age and absence of postprocedural antithrombotic therapy was detected as other negative factors in JR-NET2. The ratios of favorable outcome in poor grade patients were 25.4% in JR-NET1 and 31.3% in JR-NET2, which seemed compatible with the previous studies. These results may provide a baseline data for the NET in this disease and could be useful for validating the benefits of novel devices.

Endovascular Treatment of Aneurysmal Subarachnoid Hemorrhage in Japanese Registry of Neuroendovascular Therapy (JR-NET) 1 and 2

To distinguish the characteristics of ruptured cerebral aneurysm that are suitable for endovascular treatment from those that are not, we evaluated factors that influenced the results of aneurysm embolization in patients with ruptured cerebral aneurysm, based on data from the Japanese Registry of Neuroendovascular Therapy (JR-NET) 1 and 2. The multivariate analysis revealed that young patients, patients with low modified Rankin Scale (mRS) scores before onset, and patients with low World Federation of Neurosurgical Societies (WFNS) grades had good outcome. Compared to proximal internal carotid artery (ICA) aneurysms, the odds ratio of middle cerebral artery (MCA) aneurysms was 1.67, indicating poorer outcome for MCA aneurysms, and patients with small, wide-neck cerebral aneurysms had poor outcome. Patients treated after 15 days had better outcome than during other periods. The timing of treatment, however, did not influence the outcome in patients treated within 14 days. The outcome was poorer when the responsible doctor for the treatment was a specialist or a non-specialist than a supervisory doctor. The outcome of patients treated with bare platinum coils, and three dimensional (3D) rotational angiography was better, and the outcome of patients who completed treatment with body filling was poorer than in patients with complete occlusion. Perioperative hemorrhagic complications, all ischemic complications, and rebleeding occurred in 4.5%, 6.4%, and 1.4% of patients, respectively. All these complications had poor outcome factors on day 30, with odds ratios of 2.72, 2.96, and 25.49, respectively. We must be fully aware of these risk factors and determine indications for the treatment when endovascular treatment is performed as the treatment of choice for ruptured cerebral aneurysm.