Visual dysfunction and neurodegeneration caused by severe inflammatory optic neuropathy after coil embolization of a paraclinoid aneurysm: illustrative case.

BACKGROUND: Visual impairment due to delayed optic neuropathy is a rare complication of the endovascular treatment of paraclinoid aneurysms. An inflammatory response induced in the treated aneurysm wall is a known mechanism underlying this pathophysiology. The authors describe a case with severe and progressive optic neuropathy leading to neuronal degeneration and severe visual dysfunction. OBSERVATIONS: A 42-year-old female with a history of surgical clipping for a paraclinoid aneurysm presented with a recurrence. Although the patient was unaware of any visual dysfunction, a preoperative ophthalmological examination revealed mild inferior quadrantanopia in the left eye. The coil embolization procedure was uneventful; however, the following day, the patient experienced progressive visual impairment, which worsened despite the initiation of steroid therapy. Ophthalmological examination revealed a severe decrease in visual acuity and further deterioration of the visual field. Magnetic resonance imaging showed remarkable swelling and edema of the left optic nerve adjacent to the treated aneurysm. Despite continued steroid therapy, the patient's visual function did not recover well due to subsequent optic nerve degeneration. LESSONS: Optic neuropathy after endovascular procedures can lead to severe visual dysfunction. Careful management is essential, particularly when treating a symptomatic paraclinoid aneurysm, even if symptoms are only apparent on detailed examination.

Systemic immune-inflammation index in dural arteriovenous fistula: a feasible biomarker reflecting its clinical characteristics.

PURPOSE: The systemic immune-inflammation index (SII), a marker of systemic inflammation, can be calculated using peripheral blood tests. Although the SII has been reported as a feasible biomarker in various cerebrovascular diseases, no studies have explored in dural arteriovenous fistula (DAVF). A retrospective cohort study was performed to test whether the SII reflects the clinical characteristics of DAVF and whether this index could serve as a feasible biomarker. METHODS: This study included 28 patients who underwent endovascular treatment (39 sessions) for DAVF between 2014 and 2023. The SII was calculated using the following formula: platelet count multiplied by neutrophil count divided by lymphocyte count. We investigated the correlation between the SII and various clinical characteristics of DAVF, including symptom manifestation, and digital subtraction angiography findings. Additionally, we compared pre- and post-endovascular treatment changes in the SII. RESULTS: A significantly higher SII was observed in patients with multiple lesions, clinical symptoms (particularly aggressive symptoms), pseudophelebitic pattern (PPP), and sinus occlusion. Multivariate regression analysis revealed that the presence of symptoms (coefficient 270.9, P = 0.021) and PPP (coefficient 272.4, P = 0.017) were independent factors contributing to SII elevation. Notably, following endovascular treatment, there was a significant decrease in the elevated SII in patients whose symptoms resolved (P = 0.039) and where the DAVF was angiographically cured (P = 0.012). CONCLUSION: Elevation of the SII in patients with advanced DAVF and its decrease following endovascular treatment suggests that the SII reflects the disease condition and indicates its potential as a promising biomarker.

Optimal Transport System for Acute Ischemic Stroke Patients: A Cost-Effectiveness Analysis.

This study conducted cost utility analysis comparing 4 systems of transporting acute ischemic stroke patients in Hokkaido, Japan. Hypothetical patients were generated on a geographic information system, and their outcomes were estimated according to their transport time to hospitals administering tissue plasminogen activator and/or endovascular thrombectomy. The transport systems where a neurointerventionist traveled for earlier endovascular thrombectomy were most cost-effective in some rural areas, while direct transportation to comprehensive stroke centers was more cost-effective in other areas.

Allogeneic Stem Cell Therapy for Acute Ischemic Stroke: The Phase 2/3 TREASURE Randomized Clinical Trial.

Importance: Cell therapy is a promising treatment approach for stroke and other diseases. However, it is unknown whether MultiStem (HLCM051), a bone marrow-derived, allogeneic, multipotent adult progenitor cell product, has the potential to treat ischemic stroke. Objective: To assess the efficacy and safety of MultiStem when administered within 18 to 36 hours of ischemic stroke onset. Design, Setting, and Participants: The Treatment Evaluation of Acute Stroke Using Regenerative Cells (TREASURE) multicenter, double-blind, parallel-group, placebo-controlled phase 2/3 randomized clinical trial was conducted at 44 academic and clinical centers in Japan between November 15, 2017, and March 29, 2022. Inclusion criteria were age 20 years or older, presence of acute ischemic stroke (National Institutes of Health Stroke Scale [NIHSS] score of 8-20 at baseline), confirmed acute infarction involving the cerebral cortex and measuring more than 2 cm on the major axis (determined with diffusion-weighted magnetic resonance imaging), and a modified Rankin Scale (mRS) score of 0 or 1 before stroke onset. Data analysis was performed between May 9 and August 15, 2022. Exposure: Patients were randomly assigned to either intravenous MultiStem in 1 single unit of 1.2 billion cells or intravenous placebo within 18 to 36 hours of ischemic stroke onset. Main Outcomes and Measures: The primary end points were safety and excellent outcome at day 90, measured as a composite of a modified Rankin Scale (mRS) score of 1 or less, a NIHSS score of 1 or less, and a Barthel index score of 95 or greater. The secondary end points were excellent outcome at day 365, mRS score distribution at days 90 and 365, and mRS score of 0 to 1 and 0 to 2 at day 90. Statistical analysis of efficacy was performed using the Cochran-Mantel-Haenszel test. Results: This study included 206 patients (104 received MultiStem and 102 received placebo). Their mean age was 76.5 (range, 35-95) years, and more than half of patients were men (112 [54.4%]). There were no between-group differences in primary and secondary end points. The proportion of excellent outcomes at day 90 did not differ significantly between the MultiStem and placebo groups (12 [11.5%] vs 10 [9.8%], P = .90; adjusted risk difference, 0.5% [95% CI, -7.3% to 8.3%]). The frequency of adverse events was similar between treatment groups. Conclusions and Relevance: In this randomized clinical trial, intravenous administration of allogeneic cell therapy within 18 to 36 hours of ischemic stroke onset was safe but did not improve short-term outcomes. Further research is needed to determine whether MultiStem therapy for ischemic stroke has a beneficial effect in patients who meet specific criteria, as indicated by the exploratory analyses in this study. Trial Registration: ClinicalTrials.gov Identifier: NCT02961504.

Optimal allocation of physicians improves accessibility and workload disparities in stroke care.

BACKGROUND: Inequalities in access to stroke care and the workload of physicians have been a challenge in recent times. This may be resolved by allocating physicians suitable for the expected demand. Therefore, this study analyzes whether reallocation using an optimization model reduces disparities in spatial access to healthcare and excessive workload. METHODS: This study targeted neuroendovascular specialists and primary stroke centers in Japan and employed an optimization model for reallocating neuroendovascular specialists to reduce the disparity in spatial accessibility to stroke treatment and workload for neuroendovascular specialists in Japan. A two-step floating catchment area method and an inverted two-step floating catchment area method were used to estimate the spatial accessibility and workload of neuroendovascular specialists as a potential crowdedness index. Quadratic programming has been proposed for the reallocation of neuroendovascular specialists. RESULTS: The reallocation of neuroendovascular specialists reduced the disparity in spatial accessibility and the potential crowdedness index. The standard deviation (SD) of the demand-weighted spatial accessibility index improved from 125.625 to 97.625. Simultaneously, the weighted median spatial accessibility index increased from 2.811 to 3.929. Additionally, the SD of the potential crowdedness index for estimating workload disparity decreased from 10,040.36 to 5934.275 after optimization. The sensitivity analysis also showed a similar trend of reducing disparities. CONCLUSIONS: The reallocation of neuroendovascular specialists reduced regional disparities in spatial accessibility to healthcare, potential crowdedness index, and disparities between facilities. Our findings contribute to planning health policies to realize equity throughout the healthcare system.

Access to mechanical thrombectomy and ischemic stroke mortality in Japan: a spatial ecological study.

Background: Advances in stroke treatment have greatly improved outcomes; however, disparities in access to treatment might increase. Achieving equitable access to stroke treatment is a health policy challenge, as rapid treatment is essential for positive outcomes. This ecological cross-sectional study aimed to determine the relationship between the disparities in spatial accessibility to mechanical thrombectomy (SAMT) and stroke mortality rates in Japan, hypothesizing that disparities in SAMT may increase the differences in stroke mortality between regions. Methods: We used the average number of ischemic stroke (IS) deaths between 2020 and 2021 as the response variable; and SAMT, medical resources, and socioeconomic characteristics of each municipality as explanatory variables. A conditional autoregressive model was used to examine the association between the risk of stroke mortality and SAMT. The standardized mortality ratio (SMR) was mapped to understand the nationwide disparities in stroke mortality risk. Results: The median number of IS deaths was 17.5 persons per year in the municipalities (2020 to 2021). The study also found that municipalities with low SAMT were located in the northern part of Japan. The non-spatial regression model results indicated that poor accessibility, a small proportion of bachelor's degrees or higher, and a high proportion of workers in secondary industries were related to high IS mortality. Three models were evaluated using spatial analysis; Model 1 with accessibility indicators alone, Model 2 with medical resources added to Model 1, and Model 3 with socioeconomic characteristics added to Model 2. In Models 1 and 2, the population-weighted spatial accessibility index (PWSAI) showed a significant negative relationship with stroke mortality. However, this was not evident in Model 3. Mapping using Model 3 showed that the high-risk areas were predominantly located in northern Japan, excluding Hokkaido. Conclusion: Access to mechanical thrombectomy was estimated, and regional differences were observed. The relationship between accessibility and IS mortality is unknown; however, regardless of accessibility, municipalities with a high proportion of workers in secondary industries and a small proportion with bachelor's degrees or above are at risk of death from stroke.

Comparison of Access Route for Endovascular Treatment by Time-Spatial Labeling Inversion Pulse (Time-SLIP) MRA and Contrast-Enhanced MRA.

Objective: In endovascular treatment, it is important to evaluate the access route for placing a catheter into the common carotid artery (CCA) promptly and safely prior to the procedure. We examined whether non-contrast MRA using time-spatial labeling inversion pulse (Time-SLIP) can be used in patients prior to endovascular thrombectomy for acute ischemic stroke. We compared Time-SLIP MRA to contrast-enhanced (CE) MRA and evaluated the efficacy in the evaluation of access routes. Methods: We retrospectively reviewed 31 patients admitted between October 2018 and December 2018 for cerebral infarction at our hospital. Blood vessels were imaged from the aortic arch to the CCA. A radiologist blindly evaluated quality score, stenosis, shape of the aorta, and degree of tortuosity. Results: There were no "non-diagnostic" images. The sensitivity, specificity, positive predictive value, and negative predictive value for stenosis were 83%, 96%, 83%, and 96%, respectively. The sensitivity for the aorta type classification was 100%. The sensitivity for mild tortuosity was 93%, for moderate was 100%, and for severe was 100%. Conclusion: Time-SLIP MRA can be an alternative to CE MRA in access route assessment for patients with cerebral infarction who are not eligible for acute thrombectomy therapy.

Cost-effectiveness of seven-days-per-week rehabilitation schedule for acute stroke patients.

BACKGROUND: Rehabilitation is an essential medical service for patients who have suffered acute stroke. Although the effectiveness of 7-days-per-week rehabilitation schedule has been studied in comparison with 5- or 6-days-per-week rehabilitation schedule, its cost-effectiveness has not been analyzed. In this research, to help formulate more cost-effective medical treatments for acute stroke patients, we analyzed the cost-effectiveness of 7-days-per-week rehabilitation for acute stroke from public health payer's perspective, and public healthcare and long-term care payer's perspective in Japan. METHODS: Cost-effectiveness of 7-days-per-week rehabilitation for acute stroke patients was analyzed based on the result from a previous study using a Japanese database examining the efficacy of 7-days-per-week rehabilitation. Cost utility analysis was conducted by comparing 7-days-per-week rehabilitation with 5- or 6-days-per-week rehabilitation, with its main outcome incremental cost-effectiveness ratio (ICER) calculated by dividing estimated incremental medical and long-term care costs by incremental quality-adjusted life years (QALY). The costs were estimated using the Japanese fee table and from published sources. The time horizon was 5 years, and Markov modeling was used for the analysis. RESULTS: The ICER was $6339/QALY from public health payer's perspective, lower than 5,000,000 Yen/QALY (approximately US$37,913), which was the willingness-to-pay used for the cost-effectiveness evaluation in Japan. The 7-day-per-week rehabilitation was dominant from public healthcare and long-term care payer's perspective. The result of sensitivity analysis confirmed the results. CONCLUSION: The results indicated that 7-days-per-week rehabilitation for acute stroke rehabilitation was likely to be cost-effective.

Transferring neurointerventionalists saves time compared with interhospital transfer of stroke patients for endovascular thrombectomy: a collaborative pooled analysis of 1001 patients (EVEREST).

BACKGROUND: Interhospital transfer of stroke patients (drip and ship concept) is associated with longer treatment times compared with primary admission to a comprehensive stroke center (mothership concept). In recent years, studies on a novel concept of performing endovascular thrombectomy (EVT) at external hospitals (EXT) by transferring neurointerventionalists, instead of patients, have been published. This collaborative study aimed at answering the question of whether EXT saves time in the workflow of acute stroke treatment across various geographical regions. METHODS: This was a patient level pooled analysis of one prospective observational study and four retrospective cohort studies, the EVEREST collaboration (EndoVascular thrombEctomy at Referring and External STroke centers). Time from initial stroke imaging to EVT (vascular puncture) was compared in mothership, drip and ship, and EXT concepts. RESULTS: In total, 1001 stroke patients from various geographical regions who underwent EVT due to large vessel occlusion were included. These were divided into mothership (n=162, 16.2%), drip and ship (n=458, 45.8%), and EXT (n=381, 38.1%) cohorts. The median time periods from onset to EVT (195 min vs 320 min, p<0.001) and from imaging to EVT (97 min vs 184 min, p<0.001) in EXT were significantly shorter than for drip and ship thrombectomy concept. CONCLUSIONS: This pooled analysis of the EVEREST collaboration adds evidence that performing EVT at external hospitals can save time compared with drip and ship across various geographical regions. We encourage conducting randomized controlled trials comparing both triage concepts.

Spatial-temporal analysis of cerebral infarction mortality in Hokkaido, Japan: an ecological study using a conditional autoregressive model.

BACKGROUND: Accessibility to stroke treatments is a challenge that depends on the place of residence. However, recent advances in medical technology have improved health outcomes. Nevertheless, the geographic heterogeneity of medical resources may increase regional disparities. Therefore, evaluating spatial and temporal influences of the medical system on regional outcomes and advanced treatment of cerebral infarction are important from a health policy perspective. This spatial and temporal study aims to identify factors associated with mortality and to clarify regional disparities in cerebral infarction mortality at municipality level. METHODS: This ecological study used public data between 2010 and 2020 from municipalities in Hokkaido, Japan. We applied spatial and temporal condition autoregression analysis in a Bayesian setting, with inference based on the Markov chain Monte Carlo simulation. The response variable was the number of deaths due to cerebral infarction (ICD-10 code: I63). The explanatory variables were healthcare accessibility and socioeconomic status. RESULTS: The large number of emergency hospitals per 10,000 people (relative risk (RR) = 0.906, credible interval (Cr) = 0.861 to 0.954) was associated with low mortality. On the other hand, the large number of general hospitals per 10,000 people (RR = 1.123, Cr = 1.068 to 1.178) and longer distance to primary stroke centers (RR = 1.064, Cr = 1.014 to 1.110) were associated with high mortality. The standardized mortality ratio decreased from 2010 to 2020 in Hokkaido by approximately 44%. Regional disparity in mortality remained at the same level from 2010 to 2015, after which it narrowed by approximately 5% to 2020. After mapping, we identified municipalities with high mortality rates that emerged in Hokkaido's central and northeastern parts. CONCLUSION: Cerebral infarction mortality rates and the disparity in Hokkaido improved during the study period (2010-2020). This study emphasized that healthcare accessibility through places such as emergency hospitals and primary stroke centers was important in determining cerebral infarction mortality at the municipality level. In addition, this study identified municipalities with high mortality rates that require healthcare policy changes. The impact of socioeconomic factors on stroke is a global challenge, and improving access to healthcare may reduce disparities in outcomes.

Gluing blood into gel by electrostatic interaction using a water-soluble polymer as an embolic agent.

Liquid embolic agents are widely used for the endovascular embolization of vascular conditions. However, embolization based on phase transition is limited by the adhesion of the microcatheter to the embolic agent, use of an organic solvent, unintentional catheter retention, and other complications. By mimicking thrombus formation, a water-soluble polymer that rapidly glues blood into a gel without triggering coagulation was developed. The polymer, which consists of cationic and aromatic residues with adjacent sequences, shows electrostatic adhesion with negatively charged blood substances in a physiological environment, while common polycations cannot. Aqueous polymer solutions are injectable through clinical microcatheters and needles. The formed blood gel neither adhered to the catheter nor blocked the port. Postoperative computed tomography imaging showed that the polymer can block the rat femoral artery in vivo and remain at the injection site without nontarget embolization. This study provides an alternative for the development of waterborne embolic agents.

Spontaneous Obliteration of a Dissecting Aneurysm of Recurrent Artery of Heubner Monitored by Serial Magnetic Resonance Vessel Wall Imaging.

Aneurysms of the recurrent artery of Heubner (RAH) are known to be one of the uncommon cerebral aneurysms, predominantly presenting with bleeding symptoms. Previously, nine cases of the RAH aneurysms have been reported, all of which were treated surgically or endovascularly and most cases developed postoperative cerebral infarct in the ipsilateral caudate nucleus. Herein, we report a man presenting with transient ischemic attack due to diffuse cerebral vasospasm from a minor non-disabling subarachnoid hemorrhage (SAH) from an RAH aneurysm. He visited our hospital 7 days after the first experience of a thunderclap headache complaining with transient unilateral motor weakness and thin SAH in the right sylvian fissure. Diagnostic catheter angiography revealed a dissecting fusiform aneurysm (8 mm in size) originating from the left RAH contralateral to the thin SAH. Contrast-enhanced magnetic resonance vessel wall imaging (MR-VWI) helped to identify the ruptured nature of the RAH aneurysm. Owing to his delayed ischemic condition after minor SAH, he was conservatively treated with serial MR-VWI monitoring. The aneurysm was spontaneously obliterated with an asymptomatic lacunar infarct in the ipsilateral caudate nucleus in a month. Together, this case was considered as the dissecting aneurysm of RAH with a favorable outcome after the conservative management. Although long-term follow-up is mandatory because the disappearance of the vessel wall enhancement does not necessarily secure the permanent cure of the lesion, serial MR-VWI is helpful to diagnose the ruptured nature and monitor its chronological change in combination with conventional radiological imaging techniques.

The health economic effects of an imaging technology-based telemedicine system for rural neuro-emergency patient care.

OBJECTIVE: "Join," an imaging technology-based telemedicine system, allows simultaneous radiological information sharing between physically remote institutions, virtually connecting advanced medical institutions and rural hospitals. This study aimed to elucidate the health economics effect of Join for neurological telemedicine in rural areas in Hokkaido, Japan. METHODS: Information concerning 189 requests for patient transfer from Furano Kyokai Hospital, a regional rural hospital, to Asahikawa Medical University Hospital (AMUH), an advanced academic medical institution, was retrospectively collected. The Join system was established between Furano Kyokai Hospital and AMUH in February 2019. Data collected from patients between April 2017 and December 2018 were included in the non-Join group, and those collected between February 2019 and October 2020 were included in the Join group. Clinical variables, reasons for patient transfer requests, duration of hospital stay, and medical costs per patient were analyzed between these two groups. Furthermore, clinical characteristics were compared between patients who were transferred and not transferred based on Join. RESULTS: More patients were discharged < 7 days after transfer to AMUH in the non-Join group compared with the Join group (p = 0.02). When focusing on the Join group, more patients who were not transferred were discharged < 1 week (p < 0.01). On the other hand, more patients required surgery (p = 0.01) when transferred. The ratio of patients whose medical cost was < USD5000 substantially decreased, from 33% for the non-Join group to 13% for the Join group. CONCLUSIONS: An imaging technology-based telemedicine system, Join, contributed to reducing unnecessary neuro-emergency patient transfer in a remote rural area, and telemedicine with an integrated smartphone system allowed medical personnel to effectively triage at a distance neuro-emergency patients requiring advanced tertiary care.

Potential crowdedness of mechanical thrombectomy and cerebral infarction mortality in Japan: Application of inverted two-step floating catchment area method.

OBJECTIVES: This study aimed to evaluate a stroke medical delivery system based on population coverage and the potential crowdedness index (PCI) of mechanical thrombectomy and investigate the relationship between PCI and cerebral infarction mortality in Japan. MATERIALS AND METHODS: This cross-sectional study defined 662 facilities and 1605 neurointerventionalists as supply, population aged 55 years or older as demand, and set the reachable area for demand as 120 min in driving time. Multiple regression analysis adjusted for spatial autocorrelation was used to examine the relationship between PCI and cerebral infarction mortality. RESULTS: In the 2020 data, 99% of the population aged 55 years or older had access to mechanical thrombectomy (≤120 min), and the PCI ranged from 5876 to 129838, with a median of 30426. From 2020 to 2035, the PCI is estimated to increase (30426 to 32510), decreasing after 2035 (32510 to 29469). The PCI distribution exhibited geographical heterogeneity. High PCI values emerged in eastern Japan. According to regression analysis, the increase in PCI by 1% led to an increase of 0.13% in standardized mortality ratio of cerebral infarction in men. However, PCI did not significantly correlate with cerebral infarction mortality in women. CONCLUSIONS: PCI for hospitals based on supply and demand was geographically heterogeneous in Japan. Optimization of PCI contributes equalization of mechanical thrombectomy provision system and may improve cerebral infarction mortality.

Efficacy of the MRA-Based Road Mapping of the Para-Aortic Access Route before Mechanical Thrombectomy in Patients with Acute Ischemic Stroke.

INTRODUCTION: The aim of this study was to clarify whether magnetic resonance angiography (MRA)-based road mapping of the para-aortic transfemoral access route can reduce the procedural time of mechanical thrombectomy in patients with acute ischemic stroke. We further investigated the role of pre-procedural MRA-based road mapping in optimal initial catheter selection for rapid mechanical thrombectomy. MATERIALS AND METHODS: We retrospectively reviewed 57 consecutive patients with acute ischemic stroke who underwent mechanical thrombectomy at our hospital between April 2018 and May 2021. Twenty-nine patients underwent MRA-based road mapping to visualize the para-aortic access route, whereas 28 patients only underwent routine head magnetic resonance imaging/angiography without MRA-based road mapping before neuro-interventional procedures. We then compared the basic procedural times required for mechanical thrombectomy, such as the time from femoral artery puncture to recanalization ("puncture to recanalization time") and the time from the admission to recanalization ("door to recanalization time"), between the groups. RESULTS: MRA-based road mapping significantly reduced the "puncture to recanalization time" (52.0 min vs. 70.0 min; p = 0.019) and the "door to recanalization time" (146 min vs. 183 min; p = 0.013). CONCLUSION: MRA-based road mapping of the para-aortic access route is useful to reduce the procedural time of mechanical thrombectomy in acute stroke patients, possibly by enabling optimal initial catheter selection during the procedure.

Use of magnetic resonance venography for inferior petrosal sinus sampling.

BACKGROUND: Inferior petrosal sinus (IPS) sampling (IPSS) is a transvenous interventional procedure performed to diagnose Cushing's disease. The reported IPSS failure rate is approximately 10% because IPS catheter delivery is conducted blindly and is challenging because of IPS anatomical variations. This study aimed to evaluate the usefulness of preprocedural magnetic resonance venography (MRV) for assessing IPS access routes before IPSS. METHODS: Nineteen consecutive patients who underwent IPSS at a single university hospital in Japan were retrospectively studied. A preprocedural MRV protocol optimized to visualize the IPS before IPSS was established and utilized in the eight most recent cases. An IPSS procedure was considered successful when bilateral IPS catheterization was accomplished. Patient demographics, IPSS success rate, and radiation dose required during IPSS were compared between two groups: MRV group (N = 8) and no-MRV group (N = 11) before IPSS. RESULTS: There were no significant differences in age, sex, and IPSS success rates between the groups. The average radiation dose was 663.6 ± 246.8 (SD) mGy and 981.7 ± 389.5 (SD) mGy in the MRV group and no-MRV group, respectively. Thus, there was a significant reduction in radiation exposure in the MRV group (p = 0.044). Catheterization of the left IPS was unsuccessful in only one patient in the MRV group owing to IPS hypoplasty, as found on the MRV. CONCLUSIONS: Hypoplastic IPSs occur in patients and can complicate IPSS. Preprocedural MRV assessment is useful for understanding venous anatomy and preventing unnecessary intravenous catheter manipulation during IPSS, which involves blind manipulation around the IPS.

Efficacy of Carotid Artery Stenting Performed under General Anesthesia with Somatosensory Evoked Potential Monitoring.

OBJECTIVES: During carotid artery stenting (CAS), hemodynamics may be affected by the carotid sinus reflex in some cases. Although general anesthesia has been reported to stabilize intraoperative hemodynamics, the patient's neurological condition must be assessed indirectly. Therefore, we investigated the changes in intraoperative hemodynamics and perioperative complications of CAS under general anesthesia and evaluated the efficacy of somatosensory evoked potential (SEP) monitoring in detecting a reduction in perfusion during CAS. MATERIALS AND METHODS: From April 2011 to August 2016,57 consecutive patients who underwent CAS under general anesthesia were evaluated. The follow-up period ranged from 3 to 8 years. During CAS, anesthesiologists monitored and managed the hemodynamics. SEP monitoring was performed during the CAS procedure in all patients. RESULTS: Intraoperative hypotension (systolic blood pressure ≤ 100 mmHg) was evident in 16 patients (28.1%), and 13 patients (22.8%) experienced intraoperative bradycardia; however, all of these cases were promptly managed under general anesthesia. None of the patients showed systolic blood pressure < 50 mmHg from baseline. Regarding perioperative complications, none of the patients exhibited myocardial infarction or postoperative hyperperfusion symptoms, and there was no mortality. Among 21 patients (36.8%) with a decrease in the intraoperative SEP, 3 (5.3%) exhibited transient ischemic symptoms and 1 (1.8%) had postoperative infarction. CONCLUSIONS: CAS under general anesthesia is a safe and effective management option in terms of intraoperative hemodynamic stability. In addition, our findings indicate that SEP monitoring could be helpful in evaluating transient postoperative cerebral ischemia or cerebral infarction after CAS.

Intraoperative Identification of the Shunt Point of Spinal Arteriovenous Malformations by a Selective Arterial Injection of Saline to Subtract Signals of Indocyanine Green: Technical Note.

BACKGROUND: It is crucial to identify a shunt point for spinal arteriovenous malformation (AVM) treatment. For this purpose, some intraoperative supports have been reported-intravenous injection of indocyanine green (ICG), selective arterial injection of ICG, and selective arterial injection of saline with a high frame rate digital camera. However, there are difficulties in accurately identifying the shunt point, especially if the lesion has multiple feeders. The aim of this technical note was to report a novel method, selective arterial injection of saline to subtract signals of ICG, to precisely identify perimedullary arteriovenous fistula shunt points having multiple feeding arteries. METHODS: After exposing the lesion, a 4-F catheter was cannulated into the origins of the segmental artery. ICG was injected intravenously as a first step, and then heparinized saline solution was flushed from the catheter. RESULTS: Compared with other methods, this method could identify the exact shunt point and was effective for certain shunt point obliterations. CONCLUSIONS: Despite having similar invasiveness, selective arterial injection of saline to subtract signals of ICG is superior to previously described techniques, such as selective arterial injection of ICG. Therefore, it will be useful in spinal arteriovenous malformation surgical treatment.

Analyzing Cost-Effectiveness of Allocating Neurointerventionist for Drive and Retrieve System for Patients with Acute Ischemic Stroke.

OBJECTIVES: There are regional disparities in implementation rates of endovascular thrombectomy due to time and resource constraints such as endovascular thrombectomy specialists. In Hokkaido, Japan, Drive and Retrieve System (DRS), where endovascular thrombectomy specialists perform early endovascular thrombectomies by traveling from the facilities where they normally work to facilities closer to the patient. This study analyzed the cost-effectiveness of allocating a endovascular thrombectomy specialist for DRS to treat stroke patients. MATERIALS AND METHODS: he number of ischemic stroke patients expected to receive endovascular thrombectomy in Hokkaido in 2015 was estimated. It was assumed that an additional neutointerventionist was allocated for DRS. The analysis was performed from the government's perspective, which includes medical and nursing-care costs, and the personnel cost for endovascular thrombectomy specialist. The analysis was conducted comparing the current scenario, where patients received endovascular thrombectomy in facilities where endovascular thrombectomy specialists normally work, with the scenario with DRS within 60 min drive distance. Patient transport time was analyzed using geographic information system, and patient severity was estimated from the transport time. The primary outcome was incremental cost-effectiveness ratio (ICER) in each medical area which was calculated from the incremental costs and the incremental quality-adjusted life years (QALYs), estimated from patient severity using published literature. The entire process was repeated 100 times. RESULTS: DRS was most cost-effective in Kamikawachubu area, where the ICER was $14,173±16,802/QALY, significantly lower than the threshold that the Japanese guideline suggested. CONCLUSIONS: Since DRS was cost-effective in Kamikawachubu area, the area should be prioritized when a endovascular thrombectomy specialist for DRS is allocated as a policy.