Endovascular treatment of cerebrovascular diseases and intracranial neoplasms

Combined intravenous and intra-arterial thrombolysis in hyperacute cerebral ischemia without significant corresponding vascular occlusion/stenosis: A Preliminary investigation

Objective

In this study, we assessed the efficacy and safety of various thrombolytic treatment protocols in patients with hyperacute cerebral infarction.

Methods

Patients diagnosed with acute ischemic stroke within 6 h of symptom onset and with brain computer tomography angiography confirming the absence of major vessel stenosis or occlusion were eligible for this study. The enrolled patients were subsequently randomized into two groups: all the groups received the standard intravenous thrombolysis treatment with rt-PA (0.9 mg/kg), and the experimental group underwent sequential intra-arterial thrombolysis treatment with alteplase (0.3 mg/kg, with a maximum dose of 22 mg), administered directly into the target vessel via a microcatheter. Both groups were closely monitored for changes in their National Institutes of Health Stroke Scale (NIHSS) score, modified Rankin scale score, hemorrhage rate, all-cause mortality rate, and the rate of favorable outcomes at 90 ± 7 days.

Results

Ninety-four participants were enrolled in this study, with both the control and experimental groups initiating intravenous injection of rt-PA at a median time of 29 min. For the experimental group, the median time for arterial puncture was 123 min. Baseline data for both groups were similar (P > 0.05). Hemorrhagic transformation occurred in 24.47 % (23 patients), with a lower intracranial hemorrhage rate observed in the experimental group compared to the control group (15.2 % vs 33.3 %, P < 0.05). Asymptomatic hemorrhage rates were 8.7 % for the experimental group and 12.5 % for the control group, with no hemorrhage detected in other locations. Post-treatment median NIHSS scores were lower in the experimental group than in the control group (7 vs 9, P < 0.05), but short-term NIHSS scores were similar (P > 0.05). A higher proportion of patients in the experimental group achieved favorable outcomes compared to the control group (87.0 % vs 43.8 %, P < 0.05).

Conclusion

In patients with acute ischemic stroke with an onset time of ≤6 h and no major intracranial vessel occlusion, combining rt-PA intravenous thrombolysis with intra-arterial thrombolysis via a microcatheter might yield superior functional outcomes.

Balloon-mounting stent versus balloon angioplasty for intracranial arterial stenosis: A systematic review and meta-analysis

BACKGROUND

Intracranial artery atherosclerotic stenosis (ICAS) is a major cause of stroke, especially in Asian countries. Current treatment options, including balloon-mounted stent (BMS) and balloon angioplasty (BA), lack sufficient evidence to determine a preferred approach. This systematic review and meta-analysis aimed to compare the efficacy and safety of BMS and BA in treating ICAS.

METHODS

Following PRISMA 2020 guidelines, we conducted a comprehensive search in PubMed, Web of Science, and Scopus up to December 1, 2023. Eligible studies compared BMS with BA in patients diagnosed with ICAS. Primary outcomes included the success rate and occurrence of stroke (ischemic or hemorrhagic). Secondary outcomes were perforator occlusion, in-stent thrombosis, death, and restenosis. Statistical analysis was conducted using R software version 4.3.1, employing a random-effects model.

RESULTS

Five high-quality studies involving 707 patients (515 males, 192 females) were included. BMS had a significantly higher success rate compared to BA (Risk Ratio [RR]: 1.13; CI: 1.03 to 1.24, p < 0.01; I2 = 14 %). The overall risk for stroke (ischemic and hemorrhagic) was significantly higher in BMS (RR: 2.97; CI: 1.32 to 6.67, p < 0.01; I2 = 0 %). However, no significant difference was found between BMS and BA regarding ischemic stroke (RR: 2.33; CI: 0.80 to 6.74, p = 0.12; I2 = 0 %). Additionally, no significant differences were observed in terms of perforator occlusion, in-stent thrombosis, dissection, minor and major strokes, and mortality rates. BMS was associated with a lower risk of restenosis (RR: 0.31; 95 % CI: 0.12 to 0.83, p = 0.02; I2 = 0 %).

CONCLUSION

Our results indicate that BMS might be associated with higher success and lower restenosis rates than BA in the treatment of ICAS but with an increased overall risk of stroke. No significant differences were observed in ischemic stroke, perforator occlusion, in-stent thrombosis, dissection, minor and major strokes, and mortality rates. The choice of treatment should consider these findings, alongside the technical challenges and desired angiographic outcomes. Future randomized controlled trials are necessary to further elucidate these results.

Bibliometric analysis of China's contribution to the knowledge system of cerebrovascular intervention

Background

Cerebrovascular disease has become the leading cause of death in China. The purpose of this article is to analyze China’s contribution to the interventional treatment of cerebrovascular diseases.

Methods

Bibliometric analysis was used for evaluating the quantity, quality, research hotspots, and cooperation network of publications regarding interventional treatment of cerebrovascular diseases from China. These articles were searched from the database of Web of Science Core Collection. The authors, publication years, citation times, regions, and source journals of retrieved articles were recorded. Network analysis and visualization were performed on Citespace5.6.

Results

From 1991 to 2019, a total of 5052 articles regarding cerebrovascular intervention were contributed by Chinese researchers. The number of publications from China grew fastest annually in the latest 5 years among countries. These publications were cited 61,216 times, with 12.12 average citations per item. The h-index was 82. Affiliated hospitals of Capital Medical University contributed most articles. Cerebral ischemia and intracranial aneurysm were the most popular keywords over the three decades. The timeline view of keywords indicated that cerebral ischemia always was a hot spot. Stent techniques were the main treatment tools and still had a strong developing trend. Neural regeneration and neuroprotection were the hot topics of basic researches related to cerebrovascular intervention.

Conclusions

The number of researches grows rapidly in China over the decades, but the quality still needs further improvement. The increasing contributions of Chinese researchers to the global knowledge system of cerebrovascular intervention are promising.

Traumatic epidural hematoma treated with endovascular coil embolization

Background:

Traumatic cerebrovascular injury may result in epidural hematoma (EDH) from laceration of the middle meningeal artery (MMA), which is a potentially life-threatening emergency. Treatment ranges from surgical evacuation to conservative management based on a variety of clinical and imaging factors.

Case Description:

A 14-year-old male presented to our institution after falling from his bicycle with traumatic subarachnoid hemorrhage and a right frontotemporal EDH. The patient did not meet criteria for surgical evacuation and endovascular embolization of the right MMA was performed. Rapid resolution of the EDH was observed.

Conclusion:

This case corroborates the sparse existing literature for the potential role of endovascular embolization to treat acute EDH in carefully selected patients who do not meet or have borderline indications for surgical management.

The 100 most cited articles in the endovascular treatment of brain arteriovenous malformations

BACKGROUND:

The literature base for endovascular treatment of brain arteriovenous malformations (BAVMs) has grown exponentially in recent decades. Bibliometric analysis has been used to identify impactful articles in other medical specialties. The aim of this citation analysis was to identify and characterize the top 100 most cited articles in the field of endovascular BAVM treatment.

METHODS:

The top-cited papers were identified by searching selected keywords (“endovascular treatment,” “interventional treatment,” “brain arteriovenous malformation,” “emboliz(s)ation”) on the Web of Science platform. The top 100 articles were ranked according to their number of citations. Each article was further evaluated to obtain predefined characteristics including citation(s) per year, year of publication, authorship, journal-title and impact factor, article topics, article type, and level of evidence.

RESULTS:

The top 100 most cited articles for endovascular BAVM treatment were published between 1960 and 2014. The total number of citations for these articles ranged from 56 to 471 (median 85.5). Most articles (76%) were published between 1990 and 2009 in three journals (56%), originated in the USA (52%) followed by France (16%). The most common topic related to embolization agents and the majority of articles constituted level IV or V evidence.

CONCLUSIONS:

This study provides a comprehensive overview of the most cited articles in the field of endovascular BAVM treatment. Our analysis recognizes key contributions from authors and institutions in the field and leads to a better understanding of the evidentiary framework for BAVM treatment.

National Trends in the Treatment of Ruptured Cerebral Aneurysms in Korea Using an Age-adjusted Method

BACKGROUND

Two primary treatment methods are used for ruptured cerebral aneurysms, surgical clipping and endovascular coiling. In recent decades, endovascular coiling has shown remarkable progress compared to surgical clipping, along with technological developments. The aim of this study was to investigate the recent trends in treatments for ruptured cerebral aneurysms in Korea.

METHODS

The data were obtained from the National Health Insurance database. We evaluated the trends in endovascular coiling and surgical clipping for ruptured aneurysms for the period 2000-2017. We obtained the number of prescriptions with International Classification of Diseases, 9th Revision, clinical modification codes related to nontraumatic subarachnoid hemorrhage and prescription codes S4641/4642 for surgical clipping and M1661/1662 for endovascular coiling. The medical expenses for each prescription were also obtained. The primary outcomes included the cumulative number of patients, patient rates per 100,000 people, and the correlation between patient rates and the percentage of the population in each age group.

RESULTS

In the case of surgical clipping, there were no increasing or decreasing trends in the cumulative number of patients when the population/age group was ignored. When examining the trends in patient rates per 100,000 population at each year in male, there was no increasing or decreasing trend in the number of surgical clippings between the age groups, in spite of a decreasing tendency in the number of surgical clipping in male in their 40s and older than 60. In females, the surgical clipping rates tended to decrease only in patients older than 60 years, but there was no tendency to increase or decrease in the other ages. In contrast, the cumulative number of patients who underwent endovascular coiling for ruptured cerebral aneurysms increased year by year regardless of the population/age group. In both male and female, there was no increasing or decreasing trend only in the group aged 40 or younger and there was an increasing tendency in the rest of the age groups. In the trend of medical expenses, both the cost of surgical clipping and endovascular coiling showed increases. Specifically, the medical expense trend in endovascular coiling increased more rapidly than that for surgical clipping.

CONCLUSION

There was a significant increase in the proportion of patients with ruptured aneurysms undergoing endovascular coiling between 2010 and 2017, whereas the use of surgical clipping decreased. The endovascular coiling was significantly increased in all age groups and surgical clipping was decreased in all age groups, especially in patients under 50 years of age.

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.

A multiscale computational modeling for cerebral blood flow with aneurysms and/or stenoses

A 1-dimensional (1D)-3-dimensional (3D) multiscale model for the human vascular network was proposed by combining a low-fidelity 1D modeling of blood circulation to account for the global hemodynamics with a detailed 3D simulation of a zonal vascular segment. The coupling approach involves a direct exchange of flow and pressure information at interfaces between the 1D and 3D models and thus enables patient-specific morphological models to be inserted into flow network with minimum computational efforts. The proposed method was validated with good agreements against 3 simplified test cases where experimental data and/or full 3D numerical solution were available. The application of the method in aneurysm and stenosis studies indicated that the deformation of the geometry caused by the diseases may change local pressure loss and as a consequence lead to an alteration of flow rate to the vessel segment.

Targeting NLRP3 Inflammasome in the Treatment of CNS Diseases

Central nervous system (CNS) is one of the largest killers of people’s health all over the world. The overactivation of the immune and inflammatory responses is considered as an important factor, contributing to the pathogenesis and progression of CNS disorders. Among all kinds of immune and inflammatory reaction, the inflammasome, a complex of proteins, has been drawn increasingly attention to by researchers. The initiation and activation of the inflammasome is involved in the onset of various kinds of diseases. The NLRP3 inflammasome, the most studied member of the inflammasome, is closely associated with many kinds of CNS disorders. Here in this review, the roles of the NLRP3 inflammasome in the pathogenesis and progression of several well-known CNS diseases would be discussed, including cerebrovascular diseases, neurodegenerative diseases, multiple sclerosis, depression as well as other CNS disorders. In addition, several therapeutic strategies targeting on the NLRP3 inflammasome for the treatment of CNS disorders would be described in this review.

Complete resection of hypervascularised extraventricular neurocytoma after preoperative embolisation

A 13-year-old female arrived at the Emergency Department with a two-week history of headache, and bilateral papilloedema on examination. The initial study with CT and MRI showed a large multicystic left frontal mass with calcification surrounded by peripheral oedema, subacute intralesional bleeding and association of multiple large vessels. She was initially operated on in another centre where a subacute haematoma was found, evacuating to multiple vessels and arteriolised veins. Despite the earlier neuroimaging findings, arteriovenous malformation (AVM) was suspected, so she was referred to our centre for further treatment. We performed angiography, MR angiography and MRI with advanced sequences, diagnosing a highly vascularised intra-axial tumour which was embolised. The patient was then definitively operated on, with the resulting finding of extraventricular neurocytoma (EVN). EVN are extremely rare lesions, not previously described in the literature as hypervascularised lesions, which in our case required prior angiography and embolisation for proper diagnosis and adequate management.

Ten Years of Advances in Neuroendovascular Procedures

Since the world was first introduced to the concept of endovascular aneurysm repair by Parodi's landmark procedures in 1990, stent-grafts have assumed a prominent role in the management of abdominal aortic aneurysm. Most modern systems are trackable, accurate, and secure. The resulting endovascular procedure is safe, durable, effective, and versatile. Perhaps the most significant increment in the applicability of the endovascular technique was achieved by the development of bifurcated stent-grafts, which dispensed with inadequate distal aortic implantation sites. Additional branches and fenestrations now permit endovascular repair in cases of thoracoabdominal, pararenal, juxtarenal, and bilateral iliac aneurysms. These advances in device performance have been accompanied by a rapid dissemination of necessary skills, leading to the development of a new superspecialty of vascular therapy, with elements of vascular surgery, interventional radiology, and interventional cardiology.

Plasmin (Human) Administration in Acute Middle Cerebral Artery Ischemic Stroke: Phase 1/2a, Open-Label, Dose-Escalation, Safety Study

BACKGROUND

This phase 1/2a, open-label, multicenter, dose-escalation, safety study describes the first evaluation of plasmin as an intracranial thrombolytic treatment for acute ischemic stroke in the middle cerebral artery. The rationale for intrathrombus administration is that plasmin would bind fibrin inside the targeted clot, protecting it from circulating inhibitors.

METHODS

Plasmin was given in escalating doses within 9 hours of stroke onset, and treatment efficacy was determined in 5 patient cohorts (N = 40): cohort 1 (20 mg, .5 mL/min), cohort 2a (40 mg, .05 mL/min), cohort 2b (40 mg, .33 mL/min), cohort 3a (80 mg, .67 mL/min), and cohort 3b (80 mg, .33 mL/min).

RESULTS

Plasmin was generally safe at doses as high as 80 mg. No symptomatic intracranial hemorrhage was observed, and the rate of asymptomatic intracranial hemorrhage (12.5%) was consistent with that expected under supportive care. No relationship was observed between the plasmin dose and the incidence or severity of bleeding events, any particular serious adverse events, nor death. Changes in clinical chemistry, hematology, and coagulation parameters following plasmin treatment were unremarkable and unrelated to the dose. Plasmin administration resulted in successful reperfusion of the occluded vessel in 25% of patients across all cohorts, with no relationship between successful perfusion and total plasmin dose but a potential increase in reperfusion with slower infusion rates.

CONCLUSIONS

Plasmin treatment of the occluded middle cerebral artery within 9 hours of stroke onset was well tolerated and did notincrease adverse outcomes; however, successful recanalization was achieved in only a limited number of patients.

Synthesis and characterization of shape-memory poly carbonate urethane microspheres for future vascular embolization

Two types of shape memory poly carbonate urethanes (PCUs) microspheres were synthesized by pre-polymerization and suspension polymerization, based on Polycarbonate diol (PCDL) as the soft segment, Isophorone diisocyanate (IPDI) and 1,6-hexamethylene diisocyanate (HDI) as the hard segments and 1,4-butanediol (BDO) as the chain expanding agent. The structure, crystallinity, and thermal property of the two synthesized PCUs were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Differential scanning calorimetery (DSC), respectively. The results showed that the two types of PCUs exhibited high thermal stability with phase separation and semi-crystallinity. Also, the results of the compression test displayed that the shape fixity and the shape recovery of two PCUs were more than 90% compared to the originals, indicating their similar bio-applicability and shape-memory properties. The tensile strength, elongation at break was enhanced by introducing and increasing content of HDI. The water contact angles of PCUs decreased and their surface tension increased by surface modified with Bovine serum albumin (BSA). Furthermore, the biological study results of two types of PCUs from the platelet adhesion test and the cell proliferation inhibition test indicated they had some biocompatibilites. Hence, the PCU microspheres might represent a smart and shape-memory embolic agent for vascular embolization.

Comparison of a Balloon Guide Catheter and a Non-Balloon Guide Catheter for Mechanical Thrombectomy

Purpose To evaluate the effectiveness of mechanical thrombectomy with the use of a stent retriever in acute ischemic stroke, performed by using a balloon guide catheter or non-balloon guide catheter. Materials and Methods In accordance with the institutional review board approval obtained at the two participating institutions, retrospective analysis was performed in 183 consecutive patients treated between 2013 and 2014 for occlusions in the middle cerebral artery or carotid terminus by using a stent retriever with a balloon guide catheter (n = 102) at one center and a non-balloon guide catheter (n = 81) at the other center. Data on procedure duration, number of passes, angiographic findings, type of stent retriever used, and expertise of the operators were collected. Successful recanalization was defined as grade 3 or 2b modified Treatment in Cerebral Ischemia recanalization accomplished in up to three passes. Univariate and multivariate subgroup analyses were conducted to control for the confounding variables of prior thrombolysis, location of occlusion, and operator expertise. Results Successful recanalization with the balloon guide catheter was achieved in 89.2% of thrombectomies (91 of 102) versus 67.9% (55 of 81) achieved with the non-balloon guide catheter (P = .0004). The one-pass thrombectomy rate with the balloon guide catheter was significantly higher than for that with the non-balloon guide catheter (63.7% [65 of 102] vs 35.8% [29 of 81], respectively; P = .001). The procedure duration was significantly shorter by using the balloon guide catheter than the non-balloon guide catheter (median, 20.5 minutes vs 41.0 minutes, respectively; P < .0001). Conclusion The effectiveness of mechanical thrombectomy with stent retrievers in acute ischemic stroke in the anterior circulation in terms of angiographic results and procedure duration was improved when performed in combination with the balloon guide catheter. (©) RSNA, 2016.

Development of a smart guide wire using an electrostrictive polymer: option for steerable orientation and force feedback

The development of steerable guide wire or catheter designs has been strongly limited by the lack of enabling actuator technologies. This paper presents the properties of an electrostrive actuator technology for steerable actuation. By carefully tailoring material properties and the actuator design, which can be integrated in devices, this technology should realistically make it possible to obtain a steerable guide wire design with considerable latitude. Electromechanical characteristics are described, and their impact on a steerable design is discussed.

Arteriovenous malformation within an isocitrate dehydrogenase 1 mutated anaplastic oligodendroglioma

Background:

The co-occurrence of intracranial arteriovenous malformations (AVMs) and cerebral neoplasms is exceedingly rare but may harbor implications pertaining to the molecular medicine of brain cancer pathogenesis.

Case Description:

Here, we present a case of de novo AVM within an isocitrate dehydrogenase 1 mutated anaplastic oligodendroglioma (WHO Grade III) and review the potential contribution of this mutation to aberrant angiogenesis as an interesting case study in molecular medicine.

Conclusion:

The co-occurrence of an IDH1 mutated neoplasm and AVM supports the hypothesis that IDH1 mutations may contribute to aberrant angiogenesis and vascular malformation.

Major publications in the critical care pharmacotherapy literature: January-December 2013

PURPOSE

Ten recently published articles with important implications for critical care pharmacotherapy are summarized.

SUMMARY

The Critical Care Pharmacotherapy Literature Update (CCPLU) group is a national assembly of experienced intensive care unit (ICU) pharmacists across the United States. Group members monitor 25 peer-reviewed journals on an ongoing basis to identify literature relevant to pharmacy practice in the critical care setting. After evaluation by CCPLU group members, selected articles are chosen for summarization and distribution to group members nationwide based on (1) applicability to critical care practice, (2) relevance to pharmacy practitioners, and (3) quality of evidence or research methodology. Hundreds of relevant articles were evaluated by the group during the period January-December 2013, of which 98 were summarized and disseminated nationally to CCPLU group members. Among those 98 publications, 10 deemed to be of particularly high utility to critical care practitioners were included in this review. The 10 articles address topics such as rapid lowering of blood pressure in patients with intracranial hemorrhage, adjunctive therapy to prevent renal injury due to acute heart failure, triple-drug therapy to improve neurologic outcomes after cardiac arrest, and continuous versus intermittent infusion of β-lactam antibiotics in severe sepsis.

CONCLUSION

There were many important additions to the critical care pharmacotherapy literature in 2013, including an updated guideline on the management of myocardial infarction and reports on advances in research focused on improving outcomes in patients with stroke or cardiac arrest and preventing the spread of drug-resistant pathogens in the ICU.

Acute endovascular reperfusion therapy in ischemic stroke: a systematic review and meta-analysis of randomized controlled trials

Background

Randomized controlled trials (RCTs) of endovascular therapy for acute ischemic stroke have had inconsistent results. We evaluated the efficacy and safety of endovascular therapy in published RCTs.

Methods

We performed a systematic review of RCTs of endovascular therapy with thrombolytic or mechanical reperfusion compared with interventions without endovascular therapy. Primary outcome was the frequency of good functional outcome (modified Rankin scale (mRS) of 0-2 at 90 days) and secondary outcomes were mortality at 90 days and symptomatic intracranial hemorrhage (sICH). Random-effects meta-analysis was performed and the Cochrane risk of bias assessment was used to evaluate quality of evidence.

Results

Ten studies involving 1,612 subjects were included. Endovascular therapy was not significantly associated with good functional outcome (Relative Risk [RR] =1.17; 95% CI, 0.97 to 1.42; p=0.10 and Absolute Risk Difference [ARD] =7%; 95%CI -0.1% to 14%; p=0.05); heterogeneity was moderate among studies (I²=30%). Mortality was unchanged with endovascular therapy (RR=0.92; 95 % CI, 0.75 to 1.13; p=0.45) and there was no difference in sICH (RR=1.20; 95 % CI, 0.79 to 1.82; p=0.39). The quality of evidence was low for all outcomes and the recommendation is weak for the use of endovascular therapy as per GRADE methodology.

Conclusions

Intra-arterial therapy did not show significant increase in good outcomes and no changes in either mortality or sICH in patients with acute ischemic stroke. We need further RCTs with better design and quality to evaluate the true efficacy of endovascular therapy.

Intra-arterial Thrombolysis in Second Trimester of Pregnancy. A Case Report

Here we present a successful intra-arterial thrombolysis performed in the second trimester of pregnancy (21 weeks). The intervention resulted in complete recanalization of the occluded right middle cerebral artery and favourable clinical and gestational outcome. Together with cases described in respective medical literature our report affirms that in pregnancy acute ischemic stroke could be treated effectively applying intra-arterial thrombolysis (using rt-PA). This therapy could provide opportunity to help in such desperate situations.

Intravenous versus intra-arterial thrombolysis in ischemic stroke: a systematic review and meta-analysis

BACKGROUND

Reperfusion following ischemic stroke can be attained by either intravenous thrombolysis (IVT) or intra-arterial thrombolysis (IAT). Only a limited number of randomized prospective studies have compared the efficacy and safety of IVT and IAT. This meta-analysis investigated possible clinical benefits of IAT relative to IVT in patients with acute ischemic stroke.

METHODS

We searched the PubMed, Cochrane, and Google Scholar databases through October 2013 for manuscripts that describe the findings of randomized controlled or prospective studies that evaluated the outcomes of patients with ischemic stroke who were treated with IVT or IAT. The clinical outcome measures were score on the modified Rankin scale (mRS) and mortality at 90 days. A favorable outcome was defined as an mRS score of 0 to 2.

RESULTS

For the mRS, the combined odds ratio (OR) of 3.28 (95% confidence interval (CI), 1.91 to 5.65, P < 0.001) indicated that patients who received IAT had a significantly higher chance for a favorable outcome than did those who received IVT. For mortality, the OR indicated that IAT therapy significantly reduced the proportion of patients who died within 90 days of the procedure (combined OR, 0.40; 95%CI, 0.17 to 0.92; P = 0.032).

CONCLUSION

This meta-analysis determined that IAT conferred a significantly greater probability of achieving a favorable outcome compared with IVT. There was also a significant difference in mortality rates between IAT and IVT. The studies included in this analysis were small and heterogeneous; therefore, larger randomized prospective clinical studies are necessary to further investigate this issue.

Comparing deflection measurements of a magnetically steerable catheter using optical imaging and MRI

PURPOSE

Magnetic resonance imaging (MRI) is an emerging modality for interventional radiology, giving clinicians another tool for minimally invasive image-guided interventional procedures. Difficulties associated with endovascular catheter navigation using MRI guidance led to the development of a magnetically steerable catheter. The focus of this study was to mechanically characterize deflections of two different prototypes of the magnetically steerable catheter in vitro to better understand their efficacy.

METHODS

A mathematical model for deflection of the magnetically steerable catheter is formulated based on the principle that at equilibrium the mechanical and magnetic torques are equal to each other. Furthermore, two different image based methods for empirically measuring the catheter deflection angle are presented. The first, referred to as the absolute tip method, measures the angle of the line that is tangential to the catheter tip. The second, referred to the base to tip method, is an approximation that is used when it is not possible to measure the angle of the tangent line. Optical images of the catheter deflection are analyzed using the absolute tip method to quantitatively validate the predicted deflections from the mathematical model. Optical images of the catheter deflection are also analyzed using the base to tip method to quantitatively determine the differences between the absolute tip and base to tip methods. Finally, the optical images are compared to MR images using the base to tip method to determine the accuracy of measuring the catheter deflection using MR.

RESULTS

The optical catheter deflection angles measured for both catheter prototypes using the absolute tip method fit very well to the mathematical model (R(2) = 0.91 and 0.86 for each prototype, respectively). It was found that the angles measured using the base to tip method were consistently smaller than those measured using the absolute tip method. The deflection angles measured using optical data did not demonstrate a significant difference from the angles measured using MR image data when compared using the base to tip method.

CONCLUSIONS

This study validates the theoretical description of the magnetically steerable catheter, while also giving insight into different methods and modalities for measuring the deflection angles of the prototype catheters. These results can be used to mechanically model future iterations of the design. Quantifying the difference between the different methods for measuring catheter deflection will be important when making deflection measurements in future studies. Finally, MR images can be used to reliably measure deflection angles since there is no significant difference between the MR and optical measurements.

Endovascular stroke therapy

BACKGROUND

Following the development of intravenous thrombolysis as a successful treatment for ischaemic stroke, advances in neurointerventional radiology have facilitated endovascular approaches to treatment. This article reviews the available endovascular therapeutic options and their evidence-base.

SUMMARY

Initial studies demonstrated that endovascular treatment of ischaemic stroke with intra-arterial thrombolysis and/or the use of clot-retrieval, thrombus aspiration and stent-retriever devices produced early recanalisation and reperfusion and improved neurological outcome. More recent randomised trials, however, have failed to show translation of recanalisation into successful clinical outcome with 'time to treatment' proving crucial. In this rapidly evolving field, combined therapy incorporating intravenous and intra-arterial thrombolysis in combination with endovascular clot-retrieval has been developed and further studies are expected to yield better evidence to guide the optimal treatment of acute cerebral ischaemia.

Intracranial atherosclerosis

Atherosclerotic disease often involves the intracranial arteries including those encased by cranial bones and dura, and those located in the subarachnoid space. Age, hypertension, and diabetes mellitus are independent risk factors for intracranial atherosclerosis. Intracranial atherosclerosis can result in thromboembolism with or without hypoperfusion leading to transient or permanent cerebral ischaemic events. High rates of recurrent ischaemic stroke and other cardiovascular events mandate early diagnosis and treatment. Present treatment is based on a combination of antiplatelet drugs, optimisation of blood pressure and LDL cholesterol values, and intracranial angioplasty or stent placement, or both, in selected patients.

Guidelines for the early management of patients with acute ischemic stroke: a guideline for healthcare professionals from the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

The authors present an overview of the current evidence and management recommendations for evaluation and treatment of adults with acute ischemic stroke. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators responsible for the care of acute ischemic stroke patients within the first 48 hours from stroke onset. These guidelines supersede the prior 2007 guidelines and 2009 updates.

METHODS

Members of the writing committee were appointed by the American Stroke Association Stroke Council's Scientific Statement Oversight Committee, representing various areas of medical expertise. Strict adherence to the American Heart Association conflict of interest policy was maintained throughout the consensus process. Panel members were assigned topics relevant to their areas of expertise, reviewed the stroke literature with emphasis on publications since the prior guidelines, and drafted recommendations in accordance with the American Heart Association Stroke Council's Level of Evidence grading algorithm.

RESULTS

The goal of these guidelines is to limit the morbidity and mortality associated with stroke. The guidelines support the overarching concept of stroke systems of care and detail aspects of stroke care from patient recognition; emergency medical services activation, transport, and triage; through the initial hours in the emergency department and stroke unit. The guideline discusses early stroke evaluation and general medical care, as well as ischemic stroke, specific interventions such as reperfusion strategies, and general physiological optimization for cerebral resuscitation.

CONCLUSIONS

Because many of the recommendations are based on limited data, additional research on treatment of acute ischemic stroke remains urgently needed.

Guidelines for acute ischemic stroke treatment: part II: stroke treatment

The second part of these Guidelines covers the topics of antiplatelet, anticoagulant, and statin therapy in acute ischemic stroke, reperfusion therapy, and classification of Stroke Centers. Information on the classes and levels of evidence used in this guideline is provided in Part I. A translated version of the Guidelines is available from the Brazilian Stroke Society website (www.sbdcv.com.br).

Remote control catheter navigation: options for guidance under MRI

BACKGROUND

Image-guided endovascular interventions have gained increasing popularity in clinical practice, and magnetic resonance imaging (MRI) is emerging as an attractive alternative to X-ray fluoroscopy for guiding such interventions. Steering catheters by remote control under MRI guidance offers unique challenges and opportunities.

METHODS

In this review, the benefits and limitations of MRI-guided remote control intervention are addressed, and the tools for guiding such interventions in the magnetic environment are summarized. Designs for remote control catheter guidance include a catheter tip electromagnetic microcoil design, a ferromagnetic sphere-tipped catheter design, smart material-actuated catheters, and hydraulically actuated catheters. Remote control catheter guidance systems were compared and contrasted with respect to visualization, safety, and performance. Performance is characterized by bending angles achievable by the catheter, time to achieve bending, degree of rotation achievable, and miniaturization capacity of the design. Necessary improvements for furthering catheter design, especially for use in the MRI environment, are addressed, as are hurdles that must be overcome in order to make MRI guided endovascular procedures more accessible for regular use in clinical practice.

CONCLUSIONS

MR-guided endovascular interventions under remote control steering are in their infancy due to issues regarding safety and reliability. Additional experimental studies are needed prior to their use in humans.

Angioplasty with stenting for intracranial atherosclerosis: a systematic review

OBJECTIVE

Intracranial artery stenosis can be fatal, requiring fast, safe and effective intervention. The introduction of the Wingspan™ stent system with Gateway™ percutaneous transluminal angioplasty balloon catheter has made intracranial intervention possible in a clinical trial setting. This systematic review planned to identify and review all randomized controlled trials comparing angioplasty and stenting of intracranial arteries with standard medical care.

METHODS

Electronic databases and relevant records were examined for possible trials using predefined inclusion and exclusion criteria.

RESULTS

A total of 3661 records were identified by searching several English language databases and other sources including Chinese academic journals. The recently discontinued Stenting and Aggressive Medical Management for Preventing Recurrent stroke in Intracranial Stenosis (SAMMPRIS) trial was the single qualifying study and showed clear advantage of medical management over percutaneous transluminal angioplasty and stenting (PTAS).

CONCLUSIONS

The SAMPRASS trial indicated that PTAS is associated with high complication and morbidity rates. Definitive recommendations cannot be made until convincing results from additional robustly designed randomized trials become available.

Emergency microsurgical embolectomy for the treatment of acute intracranial artery occlusion: report of two cases

Background

The main treatment for acute arterial ischemic stroke is intravenous or intra-arterial thrombolysis within a particular time window. Endovascular mechanical embolectomy is another treatment option in the case of major artery occlusion. Endovascular mechanical embolectomy is a useful technique for restoring blood flow in patients with large-vessel occlusion, and especially in those who are contraindicated for thrombolytics or in whom thrombolytic therapy has failed.

Case Report

We report herein two cases of emergency microsurgical embolectomy for the treatment of acute middle cerebral artery and internal carotid artery occlusion as an alternative treatment for major artery occlusion.

Conclusions

Emergency microsurgical mechanical embolectomy may be an alternative treatment option for restoring blood flow in selected patients with large-vessel acute ischemic stroke.

Stenting versus medical treatment for severe symptomatic intracranial stenosis

BACKGROUND AND PURPOSE

Intracranial atherosclerosis is especially prevalent in Asians, but intracranial stent placement and medical treatment for severe intracranial stenosis are controversial. Thus, we compared long-term outcomes of these 2 therapeutic approaches in an Asian population.

MATERIALS AND METHODS

Patients with angiographically proved severe (≥70%) symptomatic intracranial atherosclerosis, with or without stent placement, were retrospectively reviewed at a single center between 2002 and 2009, with adjustments for age, sex, vascular risk factors, degree of baseline stenosis, and baseline functional status.

RESULTS

Of the 114 patients followed from 3 to 36 months (mean, 17.3 months) after initial diagnosis, 53 received 56 stents in addition to medical treatment (stent-placement group), and 61 matched patients received only medical treatment (medical group). Total clinical events, including stroke, TIA, and vascular death, were 12 (22.6%) and 15 (24.6%) in the stent-placement and medical groups, respectively (P = .99). The stent-placement group had significantly better functional outcomes than the medical group (94.3% versus 78.7% for mRS scores of 0-3, P = .045). Most events in the stent-placement group occurred within the first week of the periprocedural period (17.0%) as minor embolic or perforator infarctions, and the rate of events decreased thereafter (5.7%, P = .07). Stent placement over the perforator-rich MCA and BA independently predicted periprocedural events on multivariate regression analysis. In the medical group, events increased in frequency (21.7%) and severity with time.

CONCLUSIONS

Although the total ischemic event rate was similar in the 2 groups during a 3-year follow-up, the stent-placement group had a more favorable functional outcome despite minor periprocedural strokes.

Impact of International Subarachnoid Aneurysm Trial results on treatment of ruptured intracranial aneurysms in the United States

Object

The utilization of endovascular treatment for ruptured intracranial aneurysms is expected to change since the publication of the International Subarachnoid Aneurysm Trial (ISAT) in 2002. The authors performed this analysis to determine the impact of ISAT results on treatment selection for ruptured intracranial aneurysms and associated in-hospital outcomes using nationally representative data.

Methods

We determined the national estimates of treatments used for ruptured intracranial aneurysms and associated in-hospital outcomes, length of stay, mortality, and cost incurred using the Nationwide Inpatient Survey (NIS) data. The NIS is the largest all-payer inpatient care database in the US and contains data from 986 hospitals approximating a 20% stratified sample of US hospitals. All the variables pertaining to hospitalization were compared between 2000–2002 and 2004–2006, and in-hospital outcomes were analyzed using multivariate analysis.

Results

In the 3-year periods prior to and after the ISAT, there were 70,637 and 77,352 admissions for ruptured intracranial aneurysms, respectively. There was a significant increase in endovascular treatment after publication of the ISAT (trend test, p < 0.0001) The in-hospital mortality for ruptured intracranial aneurysm admissions decreased from 27% to 24% (odds ratio [OR] 0.89, 95% CI 0.83–0.96, p = 0.003) after the publication of the ISAT. The cost of hospitalization after adjusting for procedures practices was not significantly higher after the publication of the ISAT ($21,437 vs $22,817, p < 0.89), but cost of hospitalization was higher in the post-ISAT period for patients undergoing endovascular procedure.

Conclusions

The results of the ISAT have been associated with a prominent change in practice patterns related to the treatment of ruptured aneurysms. The cost of hospitalization has increased and the mortality has decreased, presumably due to a larger proportion of patients receiving any treatment and endovascular treatment.

Predictors and Timing of Neurological Complications Following Intracranial Angioplasty and/or Stent Placement

BACKGROUND:

Transient or permanent neurological complications can occur in the periprocedural period following intracranial angioplasty and/or stent placement. Which patients are at risk and the time period for maximum vulnerability among those who undergo intracranial angioplasty and/or stent placement have not been formally studied.

OBJECTIVE:

To assess the predictors and timing of neurological complications following intracranial angioplasty and/or stent placement in the periprocedural period in a consecutive series of patients.

METHODS:

We reviewed medical records and angiograms of consecutive patients treated with intracranial angioplasty and/or stent placement in 3 academic institutions. We evaluated the effect of demographic, clinical, intraprocedural, and angiographic risk factors on subsequent development of periprocedural neurological complications. Periprocedural neurological complications were defined as new or worsening transient or permanent neurological complications that occurred during or within 1 month of the procedure. We also recorded the timing and nature of neurological complications in the periprocedural period.

RESULTS:

A total of 92 patients were included in the study (mean age ± standard deviation: 59 ± 14 years; 59 were men). The overall rate of in-hospital neurological complications was 9.8% (9 of 92 patients). Eight out of 9 neurological complications occurred either during the procedure or within 6 hours thereafter. Presence of diabetes mellitus (P = .003) and use of balloon-expandable stent (P = .09) were associated with periprocedural neurological complications. The degree of pre- and post-procedure stenosis, morphological appearance, and length of lesion were unrelated to periprocedural complications.

CONCLUSION:

Patients with diabetes mellitus and those treated with balloon expandable stents are at high risk for periprocedural neurological complications. The first 6 hours following intracranial angioplasty and stent placement represent the period of highest risk.

A Comparison of Computed Tomography Perfusion-Guided and Time-Guided Endovascular Treatments for Patients With Acute Ischemic Stroke

Background and Purpose— The role of CT perfusion (CT-P) imaging for the selection of patients with acute ischemic stroke who may benefit from endovascular treatment is not defined. The objective of this study was to determine whether CT-P-guided endovascular treatment improves clinical outcomes compared with standard endovascular treatment based on the time interval between symptom onset and presentation and noncontrast cranial CT imaging.

Methods— A retrospective study was performed comparing the clinical characteristics, complications, and clinical outcomes of patients with acute ischemic stroke who were treated using endovascular modalities based on either CT-P imaging (CT-P-guided) or time interval between symptom onset and presentation and absence of intracerebral hemorrhage or extensive ischemic changes on noncontrast cranial CT scan (time-guided).

Results— The rates of partial and complete recanalization were similar between the CT-P- and time-guided treatment groups (n=61 [88%] versus n=103 [81%]; P =0.52) regardless of whether they received intravenous recombinant tissue plasminogen activator before endovascular treatment. Comparing the CT-P-guided with the time-guided patients, favorable discharge outcome (modified Rankin Scale 0 to 2) was observed in 23 (32%) versus 41 (33%) of the patients, respectively ( P =0.9). In-hospital mortality was observed in 15 (21%) of CT-P- and 29 (23%) of time-guided patients ( P =0.74).

Conclusion— CT-P-guided endovascular treatment did not increase the rate of short-term favorable outcomes among patients with acute ischemic stroke. Prospective studies are required to validate the CT-P criteria and protocols currently in use before incorporating CT-P as a routine modality for patient selection for endovascular treatment.

The evolution and role of endovascular therapy for the treatment of intracranial atherosclerotic disease

Intracranial atherosclerotic disease (ICAD) is being seen as an increasingly important cause of transient ischemic attack and stroke. Attention on this disease entity has been focused as a result of two recent events: the publication of the WASID trial and the recent Food and Drug Administration approval of the Wingspan-Gateway stent system. This manuscript will review the evolution of the role of endovascular therapy in the management of ICAD. In addition, the available devices currently available for endovascular therapy will be reviewed with an eye toward peri-procedural and follow-up complication rates.

Intracranial atherosclerotic disease: an update

The consensus conference on intracranial atherosclerosis provides a comprehensive review of the existing literature relevant to the epidemiology, diagnosis, prevention, and treatment of intracranial atherosclerosis, and identifies principles of management and research priorities. Patients who have suffered a stroke or transient ischemic attack attributed to stenosis (50-99%) of a major intracranial artery face a 12 to 14% risk for subsequent stroke during the 2-year period after the initial ischemic event, despite treatment with antithrombotic medications. The annual risk for subsequent stroke may exceed 20% in high-risk groups. In patients with intracranial atherosclerotic disease, short-term and long-term anticoagulation is not superior to antiplatelet treatment. Overall, the subgroup analyses from randomized trials provide evidence about benefit of aggressive atherogenic risk factor management. Intracranial angioplasty with or without stent placement has evolved as a therapeutic option for patients with symptomatic intracranial atherosclerotic disease, particularly those with high-grade stenosis with recurrent ischemic symptoms, medication failure, or both. A multicenter randomized trial is currently under way to compare stent placement with intense medical management for patients with high-grade symptomatic intracranial atherosclerotic disease.

Challenging traditional beliefs: microsurgery for arteriovenous malformations of the basal ganglia and thalamus

OBJECTIVE

Arteriovenous malformations of the basal ganglia and thalamus are often managed with radiosurgery or observation, without consideration of microsurgery. Given the devastating effects of hemorrhage from these lesions, the accumulating evidence that they bleed more frequently than their lobar counterparts should prompt more creative thinking regarding their management.

METHODS

A review of the endovascular, microsurgical, and radiosurgical literature for arteriovenous malformations of the basal ganglia and thalamus was performed, with close attention to surgical approaches, obliteration rates, and procedure-related complications.

RESULTS

A complete resection rate of 91% and a mortality rate of 2.4% were found across surgical series of these lesions. These contrast with a 69% rate of complete obliteration and a 5.3% mortality rate (from latency-period hemorrhage) found when compiling results across the radiosurgical literature.

CONCLUSION

Given an appropriate surgical corridor of access, often afforded by incident hemorrhage, arteriovenous malformations of the basal ganglia and thalamus should be considered for microsurgical extirpation with preoperative embolization. In experienced hands, this approach presents an expeditious and definitive opportunity to eliminate the risk of subsequent hemorrhage and resultant morbidity and mortality.