Dear Editor,
I am writing to provide a thorough assessment of the recently published study titled "Cost-effectiveness of Endovascular Therapy for Acute Stroke with a Large Ischemic Region in Japan: Impact of the Alberta Stroke Program Early CT Score on Cost-effectiveness" [1]. While the study addresses important aspects of the economic implications of endovascular therapy (EVT) for acute ischemic stroke (AIS) in Japan, my analysis aims to delve deeper into specific methodological considerations and discuss the applicability of the study's findings in a broader context.
The primary focus of the study is the cost-effectiveness of EVT based on the Alberta Stroke Program Early CT Score (ASPECTS) for patients with AIS involving a large ischemic region. The conclusion that EVT is cost-effective for individuals with ASPECTS of 3–5 as determined by treating neurologists using MRI raises questions about the reliability and consistency of ASPECTS as a determinant of cost-effectiveness. Furthermore, the study acknowledges the variability in incremental costs and quality-adjusted life years (QALYs) associated with EVT in Japan compared to other countries. The higher incremental costs in Japan, attributed to the specific stroke care system and the frequent use of combined techniques and MRI, present challenges when applying these findings to healthcare systems with different cost structures and resource allocations.
The study acknowledges the variabilit...
Dear Editor,
I am writing to provide a thorough assessment of the recently published study titled "Cost-effectiveness of Endovascular Therapy for Acute Stroke with a Large Ischemic Region in Japan: Impact of the Alberta Stroke Program Early CT Score on Cost-effectiveness" [1]. While the study addresses important aspects of the economic implications of endovascular therapy (EVT) for acute ischemic stroke (AIS) in Japan, my analysis aims to delve deeper into specific methodological considerations and discuss the applicability of the study's findings in a broader context.
The primary focus of the study is the cost-effectiveness of EVT based on the Alberta Stroke Program Early CT Score (ASPECTS) for patients with AIS involving a large ischemic region. The conclusion that EVT is cost-effective for individuals with ASPECTS of 3–5 as determined by treating neurologists using MRI raises questions about the reliability and consistency of ASPECTS as a determinant of cost-effectiveness. Furthermore, the study acknowledges the variability in incremental costs and quality-adjusted life years (QALYs) associated with EVT in Japan compared to other countries. The higher incremental costs in Japan, attributed to the specific stroke care system and the frequent use of combined techniques and MRI, present challenges when applying these findings to healthcare systems with different cost structures and resource allocations.
The study acknowledges the variability in incremental costs and quality-adjusted life years (QALYs) associated with EVT in Japan compared to other countries. The higher incremental costs in Japan, attributed to the specific stroke care system and the frequent use of combined techniques and MRI, pose challenges when applying these findings to healthcare systems with different cost structures and resource allocations.
The discussion on the impact of baseline ASPECTS on cost-effectiveness draws parallels with a study conducted in the United States, suggesting that EVT for ASPECTS of 3 may not be cost-effective. However, caution is warranted when extrapolating these results to other countries due to substantial differences in patient characteristics, imaging modalities, and device strategies.
The study appropriately emphasizes the increasing importance of considering economic aspects as medical technology becomes more sophisticated and expensive, especially in aging populations. The adoption of cost-effectiveness analyses by the Central Social Insurance Medical Council in Japan reflects a growing awareness of the need to align healthcare expenditures with the value provided by medical technologies.
Nevertheless, the study's limitation in not examining the impact of various patient characteristics, such as age, time from stroke onset, stroke severity, and the involvement of eloquent areas, on the cost-effectiveness of EVT is a notable gap. Future research in this direction is crucial for understanding the nuanced factors that contribute to the economic viability of EVT in different patient cohorts.
In conclusion, while the study contributes valuable insights into the cost-effectiveness of EVT for a specific subgroup of stroke patients in Japan, its findings should be interpreted with caution when considering their broader applicability. Further research is needed to explore the generalizability of these conclusions to diverse healthcare settings and patient populations.
Reference:
1. Egashira S, Shin J, Yoshimura S, et alCost-effectiveness of endovascular therapy for acute stroke with a large ischemic region in Japan: impact of the Alberta Stroke Program Early CT Score on cost-effectivenessJournal of NeuroInterventional Surgery Published Online First: 10 December 2023. doi: 10.1136/jnis-2023-021068
Dear Editor,
I would like to commend the authors for their insightful study titled "Liquid embolic surface area as a predictor of chronic subdural hematoma resolution in middle meningeal artery embolization" [1]. The investigation into the correlation between liquid embolic surface area (LEA SA) and chronic subdural hematoma (cSDH) resolution in the context of middle meningeal artery embolization (MMAE) presents valuable contributions to the field. The authors employed a meticulous approach, retrospectively collecting data from 74 patients who underwent first-line MMAE with ethylene vinyl alcohol (EVOH) and utilizing 3D segmentation to quantify LEA SA. The observed correlation between greater LEA SA and enhanced cSDH resolution rates at 3 months and 6 months post-embolization is a noteworthy contribution to the field.
The study's strength lies in its unique focus on a patient group undergoing first-line MMAE for cSDH, a subset that has been relatively underrepresented in the existing literature. The authors rightly acknowledge the potential selection bias in this group, considering patients with greater midline shift or poor neurologic exams might be directed immediately to surgical treatment. Nonetheless, the results support the utilization of upfront MMAE in patients with riskier surgical profiles due to comorbidities or borderline radiographic and clinical features.
However, it is essential to scrutinize the limitations outlined by the a...
Dear Editor,
I would like to commend the authors for their insightful study titled "Liquid embolic surface area as a predictor of chronic subdural hematoma resolution in middle meningeal artery embolization" [1]. The investigation into the correlation between liquid embolic surface area (LEA SA) and chronic subdural hematoma (cSDH) resolution in the context of middle meningeal artery embolization (MMAE) presents valuable contributions to the field. The authors employed a meticulous approach, retrospectively collecting data from 74 patients who underwent first-line MMAE with ethylene vinyl alcohol (EVOH) and utilizing 3D segmentation to quantify LEA SA. The observed correlation between greater LEA SA and enhanced cSDH resolution rates at 3 months and 6 months post-embolization is a noteworthy contribution to the field.
The study's strength lies in its unique focus on a patient group undergoing first-line MMAE for cSDH, a subset that has been relatively underrepresented in the existing literature. The authors rightly acknowledge the potential selection bias in this group, considering patients with greater midline shift or poor neurologic exams might be directed immediately to surgical treatment. Nonetheless, the results support the utilization of upfront MMAE in patients with riskier surgical profiles due to comorbidities or borderline radiographic and clinical features.
However, it is essential to scrutinize the limitations outlined by the authors and contemplate potential strategies for addressing these constraints in future work. The retrospective nature of the study introduces inherent biases and limitations associated with patient selection. The inclusion of patients who underwent MMAE as a first-line therapy may skew the results, as this subgroup may not have as sizable hematomas as those managed with surgery initially. To overcome this limitation, future studies should be designed in a prospective manner with clinical equipoise, allowing for a more comprehensive and unbiased comparison between MMAE and surgical management. This would help in better understanding the relative efficacy of MMAE in different patient populations.
The study's focus on radiographic data is another limitation, as it did not include crucial clinical datapoints such as hematologic laboratory values, corticosteroid usage, antiplatelet or anticoagulation therapy, the etiology of cSDH, and comorbidities. Future research endeavors could benefit from incorporating a more comprehensive set of clinical parameters to provide a holistic understanding of the factors influencing cSDH resolution.
A notable limitation highlighted by the authors is the absence of pre-embolization DynaCT scans in the segmentation process, leading to potential artifacts from overlying bone. To enhance the accuracy of LEA SA calculation and verification, future studies should consider including both pre- and post-DynaCT scans. This approach would mitigate the impact of artifacts and provide a clearer understanding of LEA penetration into the microvasculature of the subdural membranes.
The authors' acknowledgment of these limitations demonstrates their commitment to transparency and scientific rigor. As we move forward, the field could benefit from collaborative efforts to standardize imaging protocols, ensuring consistency and comparability across studies. Additionally, exploring advanced imaging or reconstruction methods, such as dual-energy CT or secondary reconstructions with a smaller volume of interest, could further enhance the precision of LEA SA measurements.
In conclusion, while celebrating the significant insights derived from this study, it is crucial to recognize the outlined limitations as opportunities for improvement. Addressing these limitations in future research endeavors will not only strengthen the robustness of findings but also contribute to advancing the understanding of the intricate interplay between LEA SA and cSDH resolution in the context of MMAE.
Reference
1. John K, Syed S, Kaestner T, et alLiquid embolic surface area as a predictor of chronic subdural hematoma resolution in middle meningeal artery embolizationJournal of NeuroInterventional Surgery Published Online First: 28 November 2023.
I am writing to discuss the recent article titled "Incidence of intracranial hemorrhagic complications after anterior circulation endovascular thrombectomy in relation to occlusion site: a nationwide observational register study" (1). This study provides valuable insights into intracranial hemorrhage (ICH) as a potential complication of endovascular thrombectomy (EVT) in patients with anterior circulation vessel occlusion stroke. The authors conducted a comprehensive analysis, considering different occlusion sites and their associations with the incidence and severity of ICH, specifically symptomatic (sICH) and non-symptomatic (non-sICH) cases. While the study presents crucial findings, it is essential to discuss its implications and limitations.
The study's key finding of a 4.5% incidence of sICH after EVT for anterior circulation vessel occlusion stroke is consistent with previous research in this area. The recognition of differences in the frequency and severity of ICH across occlusion sites, particularly in the internal carotid artery (ICA), middle cerebral artery's first segment (M1), and the M2 and beyond, is a significant contribution to our understanding of EVT outcomes. The study suggests that ICA occlusions, despite their lower overall hemorrhage frequency, tend to result in more severe ICH, including intraventricular hemorrhages and space-occupying intracerebral hemorrhages. This observation aligns with prior stud...
I am writing to discuss the recent article titled "Incidence of intracranial hemorrhagic complications after anterior circulation endovascular thrombectomy in relation to occlusion site: a nationwide observational register study" (1). This study provides valuable insights into intracranial hemorrhage (ICH) as a potential complication of endovascular thrombectomy (EVT) in patients with anterior circulation vessel occlusion stroke. The authors conducted a comprehensive analysis, considering different occlusion sites and their associations with the incidence and severity of ICH, specifically symptomatic (sICH) and non-symptomatic (non-sICH) cases. While the study presents crucial findings, it is essential to discuss its implications and limitations.
The study's key finding of a 4.5% incidence of sICH after EVT for anterior circulation vessel occlusion stroke is consistent with previous research in this area. The recognition of differences in the frequency and severity of ICH across occlusion sites, particularly in the internal carotid artery (ICA), middle cerebral artery's first segment (M1), and the M2 and beyond, is a significant contribution to our understanding of EVT outcomes. The study suggests that ICA occlusions, despite their lower overall hemorrhage frequency, tend to result in more severe ICH, including intraventricular hemorrhages and space-occupying intracerebral hemorrhages. This observation aligns with prior studies and may be attributed to various factors, including the larger affected brain area and differences in vascular supply.
The study emphasizes the complexity of managing blood pressure following EVT, as it plays a critical role in achieving optimal reperfusion while minimizing the risk of adverse events, particularly in cases involving proximal vessel occlusions. Furthermore, the authors shed light on the administration of antithrombotic medication during EVT for ICA occlusions and its potential impact on sICH. This is particularly relevant given the rising concern regarding the risk of hemorrhagic complications associated with procedural antithrombotic medication.
The findings regarding EVT for occlusions in the M2 and beyond are promising, with a relatively lower incidence of sICH. The study suggests room for improvement in revascularization efficacy for these distal vessels. This is a significant consideration as it indicates that EVT should not be discouraged for the treatment of more distal vascular domains within the middle cerebral artery territory.
However, it is crucial to acknowledge the study's limitations. The definition of sICH in this study differs from the Heidelberg Bleeding Classification, which may affect the frequency of sICH cases. The categorization of sICH and δ-NIHSS was not complete in the registry, which might result in an underestimation of sICH. Additionally, the use of a modified ASPECT score for the estimation of the affected brain area is subject to inherent limitations, and further research may benefit from a more precise approach.
In conclusion, this study provides valuable insights into the incidence and severity of ICH following EVT for anterior circulation vessel occlusion stroke, with a particular focus on different occlusion sites. The findings have important implications for clinical practice, especially in managing blood pressure and antithrombotic medication during and after EVT. While the study's limitations should be considered, its contributions to our understanding of EVT outcomes are noteworthy and may guide future research in this area.
References:
1. Hall E, Ullberg T, Andsberg G, et alIncidence of intracranial hemorrhagic complications after anterior circulation endovascular thrombectomy in relation to occlusion site: a nationwide observational register studyJournal of NeuroInterventional Surgery Published Online First: 05 October 2023. doi: 10.1136/jnis-2023-020768
We have read with great interest the article entitled “Efficacy and mid-term outcome of middle meningeal artery embolization with or without burr hole evacuation for chronic subdural hematoma compared with burr hole evacuation alone” by Onyinzo, C., et al, published in Journal of NeuroInterventional Surgery (2021).
The article has compared the Surgical and Endovascular management of (CSDH) in the elderly population who are at high risk to developing (CSDH) due to their co-morbidities and the use of anti-thrombotic agents.
It is noted that the anti-thrombotic agents were stopped to both management arms. Upfront Middle meningeal artery embolization without stopping the anti-thrombotics, might be a strategy to mitigate the risk of cardio-embolic events.
In regards to the evaluation of the patients outcome, clinical parameters did not include motor assessment, which is a significant factor to favor a rapid surgical evacuation in these delicate patients.
As to the radiological follow up, cured (CSDH) were defined in the article with a thickness less than 10 mm. This is debatable as there are a lot of variations exists for this population in regards to brain volume and brain elasticity.
Finally, we would like to point out the timing of the follow up was not defines for all patients. This need to be harmonized better to a well-defined follow up timeline. Joyce, MD, et al,2 a suggested a time frame of 6 weeks after the treatment...
We have read with great interest the article entitled “Efficacy and mid-term outcome of middle meningeal artery embolization with or without burr hole evacuation for chronic subdural hematoma compared with burr hole evacuation alone” by Onyinzo, C., et al, published in Journal of NeuroInterventional Surgery (2021).
The article has compared the Surgical and Endovascular management of (CSDH) in the elderly population who are at high risk to developing (CSDH) due to their co-morbidities and the use of anti-thrombotic agents.
It is noted that the anti-thrombotic agents were stopped to both management arms. Upfront Middle meningeal artery embolization without stopping the anti-thrombotics, might be a strategy to mitigate the risk of cardio-embolic events.
In regards to the evaluation of the patients outcome, clinical parameters did not include motor assessment, which is a significant factor to favor a rapid surgical evacuation in these delicate patients.
As to the radiological follow up, cured (CSDH) were defined in the article with a thickness less than 10 mm. This is debatable as there are a lot of variations exists for this population in regards to brain volume and brain elasticity.
Finally, we would like to point out the timing of the follow up was not defines for all patients. This need to be harmonized better to a well-defined follow up timeline. Joyce, MD, et al,2 a suggested a time frame of 6 weeks after the treatment and then at 90 days
We believe these points will bridge the findings of the authors to the real-world practice, by accounting for more clinical and radiological parameters to consolidate recommendations of practice.
References
Catapano, J. S., Nguyen, C., Wakim, A., Albuquerque, F., & Ducruet, A. (2020). Joshua S. Catapano. Frontiers in Neurology , 11. https://doi.org/10.3389/fneur.2020.557233
Joyce, E., Bounajem, M. T., Scoville, J., Thomas, A. J., Ogilvy, C. S., Riina, H. A., Tanweer, O., Levy, E. I., Spiotta, A. M., Gross, B. A., Jankowitz, B. T., Cawley, C. M., Khalessi, A. A., Pandey, A. S., Ringer, A. J., Hanel, R., Ortiz, R. A., Langer, D., Levitt, M. R., … Grandhi, R. (2020). Middle meningeal artery embolization treatment of nonacute subdural hematomas in the elderly: a multiinstitutional experience of 151 cases. Neurosurgical Focus, 49(4). https://doi.org/10.3171/2020.7.focus20518
Jumah, F., Osama, M., Islim, A. I., Jumah, A., Patra, D. P., Kosty, J., Narayan, V., Nanda, A., Gupta, G., & Dossani, R. H. (2020). Efficacy and safety of middle meningeal artery embolization in the management of refractory or chronic subdural hematomas: a systematic review and meta-analysis. Acta Neurochirurgica, 162(3), 499–507. https://doi.org/10.1007/s00701-019-04161-3
Srivatsan, A., Mohanty, A., Nascimento, F. A., Hafeez, M. U., Srinivasan, V. M., Thomas, A., Chen, S. R., Johnson, J. N., & Kan, P. (2019). Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: Meta-Analysis and Systematic Review. World Neurosurgery, 122, 613–619. https://doi.org/10.1016/j.wneu.2018.11.167
I read with interest the paper by Pierot et al [1]. They conducted a prospective study to examine factors of delayed thromboembolic events in 335 patients after coiling of unruptured intracranial aneurysms. The number of delayed TEEs was 8. The adjusted odds ratios (95% confidence intervals) of autosomal dominant polycystic kidney disease and post-procedure aneurysm remnant at procedure completion for delayed TEEs were 27.3 (3.9 to 190.2) and 9.9 (1.0 to 51.3), respectively. They understand the lack of statistical power in the multivariate analysis and did not intend to examine the causal association. I present a comment regarding the number of events in logistic regression analysis.
The limitation in the total number of events for logistic regression analysis was simulated to improve statistical power [2]. In addition, Peduzzi et al. evaluated the effect of the number of events per variable (EPV) on the outcome in logistic regression analysis [3], concluding that the number of EPV less than 10 has some problems for the prediction of dependent variable. There is an opinion that EPV value less than 10 is also acceptable to evaluate the association by logistic regression analysis [4]. Pierot et al. observed 8 events, which was not appropriate for multivariate analysis even for examining the association instead of prediction in a prospective study. I think that wide ranges of 95% confidence intervals may reflect unstable estimates in a logistic regr...
I read with interest the paper by Pierot et al [1]. They conducted a prospective study to examine factors of delayed thromboembolic events in 335 patients after coiling of unruptured intracranial aneurysms. The number of delayed TEEs was 8. The adjusted odds ratios (95% confidence intervals) of autosomal dominant polycystic kidney disease and post-procedure aneurysm remnant at procedure completion for delayed TEEs were 27.3 (3.9 to 190.2) and 9.9 (1.0 to 51.3), respectively. They understand the lack of statistical power in the multivariate analysis and did not intend to examine the causal association. I present a comment regarding the number of events in logistic regression analysis.
The limitation in the total number of events for logistic regression analysis was simulated to improve statistical power [2]. In addition, Peduzzi et al. evaluated the effect of the number of events per variable (EPV) on the outcome in logistic regression analysis [3], concluding that the number of EPV less than 10 has some problems for the prediction of dependent variable. There is an opinion that EPV value less than 10 is also acceptable to evaluate the association by logistic regression analysis [4]. Pierot et al. observed 8 events, which was not appropriate for multivariate analysis even for examining the association instead of prediction in a prospective study. I think that wide ranges of 95% confidence intervals may reflect unstable estimates in a logistic regression analysis.
Their study is important for clarifying risk factors of delayed thromboembolic events even though the prevalence of adverse effect is low. I recommend that EPV should be kept higher by making larger sample sizes for keeping stable risk estimation.
REFERENCES
[1] Pierot L, Barbe C, Herbreteau D, et al. Delayed thromboembolic events after coiling of unruptured intracranial aneurysms in a prospective cohort of 335 patients. J Neurointerv Surg 2021;13(6):534-540.
[2] Novikov I, Fund N, Freedman LS. A modified approach to estimating sample size for simple logistic regression with one continuous covariate. Stat Med 2010;29(1):97-107.
[3] Peduzzi P, Concato J, Kemper E, et al. A simulation study of the number of events per variable in logistic regression analysis. J Clin Epidemiol 1996;49(12):1373-1379.
[4] Vittinghoff E, McCulloch CE. Relaxing the rule of ten events per variable in logistic and Cox regression. Am J Epidemiol 2007;165(6):710-718.
We read with great interest the recent paper by Vargas, et al. describing a novel beveled tip aspiration catheter with improved recanalization and patient outcome compared to conventional non-beveled tip catheters in a single-center retrospective study.[1] We want to express our sincere congratulations to the authors on this finding but also want to respectively present our disagreement on the mechanisms explaining the improved performance of the beveled tip catheter as compared to standard catheters.
The authors conclude that a primary reason for higher rate of complete clot ingestion for the beveled tip catheter relates to the area of the catheter tip. It is widely accepted that ingestion force predicts recanalization efficacy, and this force is proportional to tip area (A) and pressure drop (P). The authors note that the beveled tip leads to an ovalized tip area with a total tip area that is approximately 15% larger than a catheter with an equivalent inner diameter but standard non-beveled tip. They then propose that this 15% increase in tip area leads to a corresponding increase of ingestion force, using the standard F=A*P equation. However, this proposition is flawed. While it is true the total force is larger for the beveled tip catheter than a standard catheter, this total force includes two separate force components that are orthogonal to each other, including the ingestion force component (along the catheter’s length) that corks or ingests the clot and...
We read with great interest the recent paper by Vargas, et al. describing a novel beveled tip aspiration catheter with improved recanalization and patient outcome compared to conventional non-beveled tip catheters in a single-center retrospective study.[1] We want to express our sincere congratulations to the authors on this finding but also want to respectively present our disagreement on the mechanisms explaining the improved performance of the beveled tip catheter as compared to standard catheters.
The authors conclude that a primary reason for higher rate of complete clot ingestion for the beveled tip catheter relates to the area of the catheter tip. It is widely accepted that ingestion force predicts recanalization efficacy, and this force is proportional to tip area (A) and pressure drop (P). The authors note that the beveled tip leads to an ovalized tip area with a total tip area that is approximately 15% larger than a catheter with an equivalent inner diameter but standard non-beveled tip. They then propose that this 15% increase in tip area leads to a corresponding increase of ingestion force, using the standard F=A*P equation. However, this proposition is flawed. While it is true the total force is larger for the beveled tip catheter than a standard catheter, this total force includes two separate force components that are orthogonal to each other, including the ingestion force component (along the catheter’s length) that corks or ingests the clot and a perpendicular force directed against the catheter wall, which does not affect ingestion. In fact, the ingestion force is exactly the same between the beveled catheter and standard tip catheters, and is calculated as A*P, where A is simply the area of the ID of the catheter, as with standard catheters.
We think several other possible mechanisms underlie the improved recanalization outcome with the beveled tip catheter as compared to standard catheters. First, as the authors addressed in the discussion, the beveled tip enables better alignment of the catheter’s main axis and the ingestion force to the clot’s main axis , which allows a larger force transmitted to the clot than those with standard catheters.[2] Second, the bevel could partially separate the clot from the vessel wall, reducing the friction and enabling easier clot ingestion. Third, in the cases of the beveled tip advanced to be flush with the clot face, the space between the bevel tip and the bevel base can enable non-contact aspiration,[3] where the clot ingestion is enhanced by the retrograde aspiration blood flow. In comparison, for contact aspiration with standard catheters, the clot blocks the entire catheter tip and no retrograde flow will be created to facilitate clot ingestion.
Overall, the clinical results are very encouraging, and we hope our comments can benefit our community to achieve a more comprehensive understanding of the action mechanism of the beveled tip catheter in our community. Additional mechanistic study is warranted.
References
1. Vargas J, Blalock J, Venkatraman A, et al. Efficacy of beveled tip aspiration catheter in mechanical thrombectomy for acute ischemic stroke. J Neurointerv Surg. Published online 2020:1-5.
2. Bernava G, Rosi A, Boto J, et al. Direct thromboaspiration efficacy for mechanical thrombectomy is related to the angle of interaction between the aspiration catheter and the clot. J Neurointerv Surg. 2020;12(4):396-400.
3. Haussen DC, Bouslama M, Grossberg JA, Nogueira RG. Remote aspiration thrombectomy in large vessel acute ischemic stroke. J Neurointerv Surg. 2017;9(3):250-252.
We congratulate Drs. Srivatsan and colleagues on their paper examining the effects of endovascular coiling of unruptured intracranial aneurysms (UIAs) on cognition using the Montreal Cognitive Assessment (MoCA).1 In particular, we appreciate the efforts made to sample the patients at multiple time points including pre-intervention and at 1-month and 6-months post-intervention. The study found that coiling did not diminish neurocognitive function per the MoCA, with there also being no correlation between follow-up MoCA scores and imaging findings, the overall results being comparable to the authors’ previous paper on MoCA scores following flow diversion for UIAs.2 Intriguingly, the MoCA scores at baseline were on average below the typical cut-off of 26 points, especially given the relatively young population (mean age 55.5 years).
However, as acknowledged by the authors, the ability of the study to discern post-coiling imaging changes was limited by both the small subset of the population that received follow-up imaging (17 of 33 patients, 51.5%) and the smaller subset that underwent MRI (9 patients, 27.3%).1 Diffusion-weighted imaging (DWI) sequences of MRI are most sensitive to identifying post-procedural ischemic injury following neuro-interventional procedures like coiling.3 DWI lesions occur quite frequently; for example, in the ENACT trial (Evaluating Neuroprotection in Aneurysm Coiling Therapy), 68% of patients had new lesions post-procedure, with an average o...
We congratulate Drs. Srivatsan and colleagues on their paper examining the effects of endovascular coiling of unruptured intracranial aneurysms (UIAs) on cognition using the Montreal Cognitive Assessment (MoCA).1 In particular, we appreciate the efforts made to sample the patients at multiple time points including pre-intervention and at 1-month and 6-months post-intervention. The study found that coiling did not diminish neurocognitive function per the MoCA, with there also being no correlation between follow-up MoCA scores and imaging findings, the overall results being comparable to the authors’ previous paper on MoCA scores following flow diversion for UIAs.2 Intriguingly, the MoCA scores at baseline were on average below the typical cut-off of 26 points, especially given the relatively young population (mean age 55.5 years).
However, as acknowledged by the authors, the ability of the study to discern post-coiling imaging changes was limited by both the small subset of the population that received follow-up imaging (17 of 33 patients, 51.5%) and the smaller subset that underwent MRI (9 patients, 27.3%).1 Diffusion-weighted imaging (DWI) sequences of MRI are most sensitive to identifying post-procedural ischemic injury following neuro-interventional procedures like coiling.3 DWI lesions occur quite frequently; for example, in the ENACT trial (Evaluating Neuroprotection in Aneurysm Coiling Therapy), 68% of patients had new lesions post-procedure, with an average of 4.3 new lesions in the NA-1 arm and 6.7 lesions in the placebo arm when considering just the 147 patients with UIAs.4 Future studies will need to examine the relationship between the burden of such DWI lesions and post-procedural cognitive outcomes in further detail.
Furthermore, although the MoCA is a useful global assessment of cognitive impairment, we suspect that it may have more limited sensitivity in identifying mild post-procedural cognitive changes. As the studies by Drs. Strivatsan and colleagues with post-coiling and post-flow-diversion outcomes have shown, any potential changes are likely to be subtle. As we seek to uncover the phenotype of potential cognitive deficits after endovascular procedures for UIAs, we may seek guidance from the existing literature on vascular cognitive impairment (VCI), which is known to have a preponderance of executive dysfunction, including slowed information processing, impaired set-/task-shifting, and deficits in working memory.5 6 To help assess such domains with greater granularity, the National Institute of Neurological Disorders and Stroke (NINDS) and the Canadian Stroke Network (CSN) have proposed cognitive testing protocols as part of the NINDS-CSN VCI Harmonization Standards.7 Of the 5-minute, 30-minute, and 60-minute protocols proposed, the 30-minute test protocol (applied in the ENACT trial)4 appears to offer a helpful balance of length and granularity, with specific measures of the aforementioned domains like the Controlled Oral Word Association Test (COWAT – phonemic fluency), semantic fluency, Digit Symbol-Coding, the Hopkins Verbal Learning Test (HVLT), the Trail Making Test, as well as brief assessments of neuropsychiatric symptoms through the Center for Epidemiologic Studies – Depression (CES-D) scale and the Neuropsychiatric Inventory, Questionnaire Version (NPI-Q).7 Future studies of post-procedural cognitive changes should seek to incorporate some or all of these additional tests into their follow-up testing protocols.
References
1. Srivatsan A, Mohanty A, Saleem Y, et al. Cognitive outcomes after unruptured intracranial aneurysm treatment with endovascular coiling. J Neurointerv Surg 2020 doi: 10.1136/neurintsurg-2020-016362 [published Online First: 2020/07/24]
2. Wagner K, Srivatsan A, Mohanty A, et al. Cognitive outcomes after unruptured intracranial aneurysm treatment with flow diversion. J Neurosurg 2019:1-6. doi: 10.3171/2019.9.JNS191910 [published Online First: 2019/11/30]
3. Iosif C, Camilleri Y, Saleme S, et al. Diffusion-weighted imaging-detected ischemic lesions associated with flow-diverting stents in intracranial aneurysms: safety, potential mechanisms, clinical outcome, and concerns. J Neurosurg 2015;122(3):627-36. doi: 10.3171/2014.10.JNS132566 [published Online First: 2015/01/07]
4. Hill MD, Martin RH, Mikulis D, et al. Safety and efficacy of NA-1 in patients with iatrogenic stroke after endovascular aneurysm repair (ENACT): a phase 2, randomised, double-blind, placebo-controlled trial. Lancet Neurol 2012;11(11):942-50. doi: 10.1016/S1474-4422(12)70225-9
5. Garrett KD, Browndyke JN, Whelihan W, et al. The neuropsychological profile of vascular cognitive impairment--no dementia: comparisons to patients at risk for cerebrovascular disease and vascular dementia. Arch Clin Neuropsychol 2004;19(6):745-57. doi: 10.1016/j.acn.2003.09.008 [published Online First: 2004/08/04]
6. Nyenhuis DL, Gorelick PB, Geenen EJ, et al. The pattern of neuropsychological deficits in Vascular Cognitive Impairment-No Dementia (Vascular CIND). Clin Neuropsychol 2004;18(1):41-9. doi: 10.1080/13854040490507145 [published Online First: 2004/12/15]
7. Hachinski V, Iadecola C, Petersen RC, et al. National Institute of Neurological Disorders and Stroke-Canadian Stroke Network vascular cognitive impairment harmonization standards. Stroke 2006;37(9):2220-41. doi: 10.1161/01.STR.0000237236.88823.47
After reading the interesting article by Jeon et al, indeed, the first series of cases of revascularization in cerebral infarction, it is important to point out several aspects related to the cancer patient. Cancer is a heterogeneous group of diseases with some points in common related to cellular behavior in the face of cell division controls and their local and systemic effects. Its incidence and prevalence are increasing, and the borders of treatment are changing, as is the disease itself. Patients with active cancer, therefore, should be approached in a multidisciplinary strategy, for the management of their oncological pathology or associated patient comorbidities. Stroke does not escape this strategy, because it does not have the same clinical impact to treat a patient with an oncological disease in early staging compared to one in advanced staging or in disease progression in palliative care and short calculated survival. It is not possible to establish a general rule of treatment in stroke with active cancer for these reasons, and a careful analysis of which primary tumors, their staging or clinical evolution of response to treatment, are necessary to clarify the clinical picture of stroke treatment in the oncological disease context.
The response from the Stenting and Aggressive Medical Management for
the Prevention of Recurrent Ischemic Stroke (SAMMPRIS) trial principal
investigators (PIs) is greatly appreciated. Healthy debate helps us weed
out the details that are important in these studies and future trial
design. Although the PIs label some of the editorial comments as
"inaccuracies", one could disagree based on the information listed below....
The response from the Stenting and Aggressive Medical Management for
the Prevention of Recurrent Ischemic Stroke (SAMMPRIS) trial principal
investigators (PIs) is greatly appreciated. Healthy debate helps us weed
out the details that are important in these studies and future trial
design. Although the PIs label some of the editorial comments as
"inaccuracies", one could disagree based on the information listed below.
So let's look at the numbers and the facts.
First, they state the SAMMPRIS population was the right population to
test, based on the Warfarin versus Aspirin for Symptomatic Intracranial
Disease (WASID) trial data. However, they base this statement on the
criteria of the degree of stenosis, and some standard, but relatively
artificial epidemiological criteria, not focusing on some other important
clinical criteria. For example, the mean time of enrollment from
qualifying event to enrollment was 17 days in the WASID trial and 7 days
in the SAMMPRIS trial, so these are not exactly the same patient
populations. The patients who were stented in SAMMPRIS within 7 days of
their qualifying event did remarkably worse than the patients stented
after day 7, indicating that either these patients had unstable plaque or
some other factor that increased their risk for complications when treated
early. The Wingspan safety trial that led to FDA approval of the Wingspan
stent did NOT include patients who had stroke less than 7 days, so to
stent patients at less than 7 days from the event was another variable
introduced by the SAMMPRIS trial design that was not a part of the
original Food and Drug Administration (FDA) approval of the stent.
Second, they state that the Wingspan stent was not used off-label.
This is not exactly true. The Investigational Device Exemption (IDE) use
of the Wingspan stent in the SAMMPRIS trial was used for expanded
indications compared to the Humanitarian Device Exemption (HDE) FDA
approval. In fact, this was exactly one of the reasons that an IDE
approval was necessary for the trial. Interestingly, if one analyzes the
presenting symptoms, time to treatment, medical failure, and other
factors, only 8% of the patients enrolled in SAMMPRIS would have qualified
for the original Wingspan safety study upon which the FDA granted approval
(FDA Panel Review, March 2012, Baltimore, MD). Therefore, practices such
as treating patients before day 7 post-event, allowing TIA versus stroke
only as an entry criteria, and allowing patients who had not failed
medical therapy into the trial, were markedly expanded indications for the
stent in this trial. For this reason, one could argue that this trial was
not designed for stenting to succeed. Typically, every device trial is
initially designed for the on-label indication, and only later are there
considerations for expanded indications. This was not the paradigm used
in SAMMPRIS. In the subgroup of the 8% of patients in SAMMPRIS that
actually would have qualified for the original Wingspan safety trial,
there was no statistical difference in clinical outcomes between the
stenting and the medical therapy groups.
Third, the argument that even the subgroup of patients who previously
failed anti-platelet therapy did worse with stenting than medical therapy
is easily predictable, if you look how stented patient were managed in the
study. Many major centers test patients for anti-platelet therapy
resistance prior to stent placement, since there is a documented 15%
relative clopidogrel resistance in the population and 10% aspirin
resistance. Patients who are resistant to anti-platelet therapy are more
likely to have a thromboembolic event with a fresh stent placement, as a
nidus for platelet aggregation than someone with a chronic atherosclerotic
stenosis. The SAMMPRIS trial failed to account for possible anti-platelet
therapy resistance as many coronary stenting trials current address. In
fact, it was a protocol violation in SAMMPRIS even to measure the anti-
platelet therapy resistance.
Finally, the argument that interventionalist experience did not play
a role in the results is very short-sighted and is based on poorly
stratified data. It would be difficult to believe that anyone would argue
that less experienced stenters could have equivalent clinical results than
more experienced stenters. The average number of Wingspan stents placed
by interventionalists to qualify as a stenter in the study was 10 Wingspan
stents. This low number, as a distinction between low and high volume
stenters, would not be acceptable in any current stenting trial:
coronary, carotid, peripheral, etc. So technically, both "low volume" and
"high volume" groups analyzed by the PIs were low volume users.
The goals for the future should be to focus our attention on defining
which population will benefit most with revascularization, what is the
best timing for the procedure, and what medical therapy regimen is best
for patients with newly placed intracranial stents, which may not be the
same as the best therapy for those without stents. SAMMPRIS gives a
significant amount of information, but it is a starting point, not an end
to this therapy.
Conflict of Interest:
Dr. Alexander was an investigator in the SAMMPRIS clinical trial. He is a device proctor and consultant for Styker Neurovascular which manufactures the Wingspan stent.
We read with great joy the recent article by Kuhn et al entitled, “ Distal radial access in the anatomical snuffbox for neurointerventions: a feasibility, safety, and proof-of-concept study.” The authors should be congratulated on their work, as well as the use and maturation of the distal radial technique from diagnostic to interventional procedures. The authors detail their use of the Prelude sheaths which we agree are excellent low profile large lumen sheaths for radial access. We typically utilize the Glide Slender sheaths (Terumo) but both are excellent options. We also agree that the distal radial approach can be used for numerous interventions with access sizes from 4 to 6F, including 6F sheathless long 088 guides. Our choice for distal radial sheathless long 088 guides is Infinity LS (Stryker), and for 071 guides the Benchmark (penumbra) via a 6F sheath.
The authors noted their series was the first series to cover numerous neurointerventions with distal transradial access, however we would like to respectfully point out that we published on this topic in January of 2019 (accepted in March of 2019). Our paper by Rajah et al entitled, “ Snuff box radial access: A technical note on distal radial access for neuroendovascular procedures” can be found in Brain Circulation at the following citation available in PUBMED.
Rajah G, Garling RJ, Hudson M, Luqman A. Snuff box radial access: A technical note on distal radial access for neuroe...
We read with great joy the recent article by Kuhn et al entitled, “ Distal radial access in the anatomical snuffbox for neurointerventions: a feasibility, safety, and proof-of-concept study.” The authors should be congratulated on their work, as well as the use and maturation of the distal radial technique from diagnostic to interventional procedures. The authors detail their use of the Prelude sheaths which we agree are excellent low profile large lumen sheaths for radial access. We typically utilize the Glide Slender sheaths (Terumo) but both are excellent options. We also agree that the distal radial approach can be used for numerous interventions with access sizes from 4 to 6F, including 6F sheathless long 088 guides. Our choice for distal radial sheathless long 088 guides is Infinity LS (Stryker), and for 071 guides the Benchmark (penumbra) via a 6F sheath.
The authors noted their series was the first series to cover numerous neurointerventions with distal transradial access, however we would like to respectfully point out that we published on this topic in January of 2019 (accepted in March of 2019). Our paper by Rajah et al entitled, “ Snuff box radial access: A technical note on distal radial access for neuroendovascular procedures” can be found in Brain Circulation at the following citation available in PUBMED.
Rajah G, Garling RJ, Hudson M, Luqman A. Snuff box radial access: A technical note on distal radial access for neuroendovascular procedures. Brain circulation. 2019 Jan;5(1):36.
Our paper details our technique, the pros of anatomic orientation of the hand for both the patient and surgeon, as well as the theoretical safety of the distal radial approach with regards to ischemia. We detail how our access is performed with ultrasound, and depict 4 illustrative case examples with imaging including aneurysm stent coiling, head and neck embolization, posterior fossa parent vessel sacrifice, and carotid stenting via a sheathless approach. We had switched over our entire practice for surgeon (AL) to distal radial access in November of 2018. Since that time all diagnostic angiograms and most interventions were performed via distal radial access including ischemic strokes. We have a distal radial manuscript currently accepted to Brain Circulation detailing our use of a Balloon guide catheter for ischemic stroke, which we admit still has its limitations with the available current guides due to outside diameter (OD) and stiffness. However with newest Balloon guides recently approved by the FDA, such as those made by Q’Apel, Medical boasting an 087 ID with a flexible design may provide for sheathless radial use. A 7F 072 balloon guide is also advertised by the Q’Apel. Kuhn et al explains distal radial access can provide enough support for flow divertor deployment intracranially, we echo this finding, as we have also treated aneurysms and carotid cavernous fistulas via a distal radial approach with flow divertors in tandem or stacked fashion.
We again applaud the authors on their work, and are excited to see the field moving toward more distal radial access during the current radial revolution in the neuro endovascular world. We agree with the authors this technique is a safe and effective way to perform a variety of endovascular procedures and should be in every surgeons armamentarium.
Dear Editor,
Show MoreI am writing to provide a thorough assessment of the recently published study titled "Cost-effectiveness of Endovascular Therapy for Acute Stroke with a Large Ischemic Region in Japan: Impact of the Alberta Stroke Program Early CT Score on Cost-effectiveness" [1]. While the study addresses important aspects of the economic implications of endovascular therapy (EVT) for acute ischemic stroke (AIS) in Japan, my analysis aims to delve deeper into specific methodological considerations and discuss the applicability of the study's findings in a broader context.
The primary focus of the study is the cost-effectiveness of EVT based on the Alberta Stroke Program Early CT Score (ASPECTS) for patients with AIS involving a large ischemic region. The conclusion that EVT is cost-effective for individuals with ASPECTS of 3–5 as determined by treating neurologists using MRI raises questions about the reliability and consistency of ASPECTS as a determinant of cost-effectiveness. Furthermore, the study acknowledges the variability in incremental costs and quality-adjusted life years (QALYs) associated with EVT in Japan compared to other countries. The higher incremental costs in Japan, attributed to the specific stroke care system and the frequent use of combined techniques and MRI, present challenges when applying these findings to healthcare systems with different cost structures and resource allocations.
The study acknowledges the variabilit...
Dear Editor,
Show MoreI would like to commend the authors for their insightful study titled "Liquid embolic surface area as a predictor of chronic subdural hematoma resolution in middle meningeal artery embolization" [1]. The investigation into the correlation between liquid embolic surface area (LEA SA) and chronic subdural hematoma (cSDH) resolution in the context of middle meningeal artery embolization (MMAE) presents valuable contributions to the field. The authors employed a meticulous approach, retrospectively collecting data from 74 patients who underwent first-line MMAE with ethylene vinyl alcohol (EVOH) and utilizing 3D segmentation to quantify LEA SA. The observed correlation between greater LEA SA and enhanced cSDH resolution rates at 3 months and 6 months post-embolization is a noteworthy contribution to the field.
The study's strength lies in its unique focus on a patient group undergoing first-line MMAE for cSDH, a subset that has been relatively underrepresented in the existing literature. The authors rightly acknowledge the potential selection bias in this group, considering patients with greater midline shift or poor neurologic exams might be directed immediately to surgical treatment. Nonetheless, the results support the utilization of upfront MMAE in patients with riskier surgical profiles due to comorbidities or borderline radiographic and clinical features.
However, it is essential to scrutinize the limitations outlined by the a...
To the Editor,
I am writing to discuss the recent article titled "Incidence of intracranial hemorrhagic complications after anterior circulation endovascular thrombectomy in relation to occlusion site: a nationwide observational register study" (1). This study provides valuable insights into intracranial hemorrhage (ICH) as a potential complication of endovascular thrombectomy (EVT) in patients with anterior circulation vessel occlusion stroke. The authors conducted a comprehensive analysis, considering different occlusion sites and their associations with the incidence and severity of ICH, specifically symptomatic (sICH) and non-symptomatic (non-sICH) cases. While the study presents crucial findings, it is essential to discuss its implications and limitations.
The study's key finding of a 4.5% incidence of sICH after EVT for anterior circulation vessel occlusion stroke is consistent with previous research in this area. The recognition of differences in the frequency and severity of ICH across occlusion sites, particularly in the internal carotid artery (ICA), middle cerebral artery's first segment (M1), and the M2 and beyond, is a significant contribution to our understanding of EVT outcomes. The study suggests that ICA occlusions, despite their lower overall hemorrhage frequency, tend to result in more severe ICH, including intraventricular hemorrhages and space-occupying intracerebral hemorrhages. This observation aligns with prior stud...
Show MoreDear Editor,
We have read with great interest the article entitled “Efficacy and mid-term outcome of middle meningeal artery embolization with or without burr hole evacuation for chronic subdural hematoma compared with burr hole evacuation alone” by Onyinzo, C., et al, published in Journal of NeuroInterventional Surgery (2021).
The article has compared the Surgical and Endovascular management of (CSDH) in the elderly population who are at high risk to developing (CSDH) due to their co-morbidities and the use of anti-thrombotic agents.
Show MoreIt is noted that the anti-thrombotic agents were stopped to both management arms. Upfront Middle meningeal artery embolization without stopping the anti-thrombotics, might be a strategy to mitigate the risk of cardio-embolic events.
In regards to the evaluation of the patients outcome, clinical parameters did not include motor assessment, which is a significant factor to favor a rapid surgical evacuation in these delicate patients.
As to the radiological follow up, cured (CSDH) were defined in the article with a thickness less than 10 mm. This is debatable as there are a lot of variations exists for this population in regards to brain volume and brain elasticity.
Finally, we would like to point out the timing of the follow up was not defines for all patients. This need to be harmonized better to a well-defined follow up timeline. Joyce, MD, et al,2 a suggested a time frame of 6 weeks after the treatment...
Dear Editor,
I read with interest the paper by Pierot et al [1]. They conducted a prospective study to examine factors of delayed thromboembolic events in 335 patients after coiling of unruptured intracranial aneurysms. The number of delayed TEEs was 8. The adjusted odds ratios (95% confidence intervals) of autosomal dominant polycystic kidney disease and post-procedure aneurysm remnant at procedure completion for delayed TEEs were 27.3 (3.9 to 190.2) and 9.9 (1.0 to 51.3), respectively. They understand the lack of statistical power in the multivariate analysis and did not intend to examine the causal association. I present a comment regarding the number of events in logistic regression analysis.
The limitation in the total number of events for logistic regression analysis was simulated to improve statistical power [2]. In addition, Peduzzi et al. evaluated the effect of the number of events per variable (EPV) on the outcome in logistic regression analysis [3], concluding that the number of EPV less than 10 has some problems for the prediction of dependent variable. There is an opinion that EPV value less than 10 is also acceptable to evaluate the association by logistic regression analysis [4]. Pierot et al. observed 8 events, which was not appropriate for multivariate analysis even for examining the association instead of prediction in a prospective study. I think that wide ranges of 95% confidence intervals may reflect unstable estimates in a logistic regr...
Show MoreWe read with great interest the recent paper by Vargas, et al. describing a novel beveled tip aspiration catheter with improved recanalization and patient outcome compared to conventional non-beveled tip catheters in a single-center retrospective study.[1] We want to express our sincere congratulations to the authors on this finding but also want to respectively present our disagreement on the mechanisms explaining the improved performance of the beveled tip catheter as compared to standard catheters.
The authors conclude that a primary reason for higher rate of complete clot ingestion for the beveled tip catheter relates to the area of the catheter tip. It is widely accepted that ingestion force predicts recanalization efficacy, and this force is proportional to tip area (A) and pressure drop (P). The authors note that the beveled tip leads to an ovalized tip area with a total tip area that is approximately 15% larger than a catheter with an equivalent inner diameter but standard non-beveled tip. They then propose that this 15% increase in tip area leads to a corresponding increase of ingestion force, using the standard F=A*P equation. However, this proposition is flawed. While it is true the total force is larger for the beveled tip catheter than a standard catheter, this total force includes two separate force components that are orthogonal to each other, including the ingestion force component (along the catheter’s length) that corks or ingests the clot and...
Show MoreWe congratulate Drs. Srivatsan and colleagues on their paper examining the effects of endovascular coiling of unruptured intracranial aneurysms (UIAs) on cognition using the Montreal Cognitive Assessment (MoCA).1 In particular, we appreciate the efforts made to sample the patients at multiple time points including pre-intervention and at 1-month and 6-months post-intervention. The study found that coiling did not diminish neurocognitive function per the MoCA, with there also being no correlation between follow-up MoCA scores and imaging findings, the overall results being comparable to the authors’ previous paper on MoCA scores following flow diversion for UIAs.2 Intriguingly, the MoCA scores at baseline were on average below the typical cut-off of 26 points, especially given the relatively young population (mean age 55.5 years).
However, as acknowledged by the authors, the ability of the study to discern post-coiling imaging changes was limited by both the small subset of the population that received follow-up imaging (17 of 33 patients, 51.5%) and the smaller subset that underwent MRI (9 patients, 27.3%).1 Diffusion-weighted imaging (DWI) sequences of MRI are most sensitive to identifying post-procedural ischemic injury following neuro-interventional procedures like coiling.3 DWI lesions occur quite frequently; for example, in the ENACT trial (Evaluating Neuroprotection in Aneurysm Coiling Therapy), 68% of patients had new lesions post-procedure, with an average o...
Show MoreAfter reading the interesting article by Jeon et al, indeed, the first series of cases of revascularization in cerebral infarction, it is important to point out several aspects related to the cancer patient. Cancer is a heterogeneous group of diseases with some points in common related to cellular behavior in the face of cell division controls and their local and systemic effects. Its incidence and prevalence are increasing, and the borders of treatment are changing, as is the disease itself. Patients with active cancer, therefore, should be approached in a multidisciplinary strategy, for the management of their oncological pathology or associated patient comorbidities. Stroke does not escape this strategy, because it does not have the same clinical impact to treat a patient with an oncological disease in early staging compared to one in advanced staging or in disease progression in palliative care and short calculated survival. It is not possible to establish a general rule of treatment in stroke with active cancer for these reasons, and a careful analysis of which primary tumors, their staging or clinical evolution of response to treatment, are necessary to clarify the clinical picture of stroke treatment in the oncological disease context.
The response from the Stenting and Aggressive Medical Management for the Prevention of Recurrent Ischemic Stroke (SAMMPRIS) trial principal investigators (PIs) is greatly appreciated. Healthy debate helps us weed out the details that are important in these studies and future trial design. Although the PIs label some of the editorial comments as "inaccuracies", one could disagree based on the information listed below....
Dear Editor:
We read with great joy the recent article by Kuhn et al entitled, “ Distal radial access in the anatomical snuffbox for neurointerventions: a feasibility, safety, and proof-of-concept study.” The authors should be congratulated on their work, as well as the use and maturation of the distal radial technique from diagnostic to interventional procedures. The authors detail their use of the Prelude sheaths which we agree are excellent low profile large lumen sheaths for radial access. We typically utilize the Glide Slender sheaths (Terumo) but both are excellent options. We also agree that the distal radial approach can be used for numerous interventions with access sizes from 4 to 6F, including 6F sheathless long 088 guides. Our choice for distal radial sheathless long 088 guides is Infinity LS (Stryker), and for 071 guides the Benchmark (penumbra) via a 6F sheath.
The authors noted their series was the first series to cover numerous neurointerventions with distal transradial access, however we would like to respectfully point out that we published on this topic in January of 2019 (accepted in March of 2019). Our paper by Rajah et al entitled, “ Snuff box radial access: A technical note on distal radial access for neuroendovascular procedures” can be found in Brain Circulation at the following citation available in PUBMED.
Rajah G, Garling RJ, Hudson M, Luqman A. Snuff box radial access: A technical note on distal radial access for neuroe...
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