School of Medicine Publications and Presentations

Reply to “Letter to the Editor: Assessing the Efficacy and Limitations of Rescue Thrombectomy in Acute Ischemic Stroke”

Document Type

Letter to the Editor

Publication Date

10-2024

Abstract

Our recent study on rescue therapy (RT) utilized data from the prospective Society of Vascular and Interventional Neurology (SVIN) observational registry. The method of patient admission—whether via interhospital transfer or direct admission—is a recognized factor affecting functional outcomes and could have influenced our results. However, in well-developed systems, the addition of intravenous thrombolysis in transfer patients delays thrombectomy but does not affect outcomes.1 As commonly noted in observational studies and emphasized in our limitations, many confounding factors often go unmeasured or unadjusted. These limitations are inherent to observational studies; therefore, our findings should be interpreted with caution and considered preliminary data useful for informing future randomized trials.

Due to the lack of current guidelines on antiplatelet therapy for refractory mechanical thrombectomy cases, each of the 14 participating centers followed different protocols. This substantial heterogeneity poses a challenge for performing stratified analyses comparing the various antiplatelet protocols. Although small differences in safety might occur, our study, which is a pragmatic registry, indicates that the overall safety rate is similar across protocols. To address different surgical approaches, we compared rescue stenting versus balloon angioplasty alone within the rescue therapy group. Additionally, within the rescue stenting group, we compared the efficacy of self-expandable stents versus balloon-mounted stents.

The superiority of functional outcomes in anterior circulation strokes compared to posterior circulation strokes is well-documented in the literature,2 with underlying pathological and physiological differences extensively published.3, 4 In our article, we stratified safety outcomes between anterior and posterior circulation strokes. Posterior circulation strokes have a distinct natural history, which is why clinical outcomes in this population are measured by the proportion of patients with a modified Rankin Scale (mRS) score of 0 to 3, rather than 0 to 2 mRS. Regarding safety outcomes, we found no significant differences, suggesting that these outcomes are unlikely to have influenced our results. The observed differences are more likely due to the severity of the disease and the small sample size.

Similar to the presence of unmeasured confounders, the absence of long-term outcomes of RT, such as arterial patency or stroke recurrence, was also mentioned in our study's limitations. We plan to conduct a randomized trial exploring the effects of RT on intracranial atherosclerosis to determine the true impact of this intervention. We appreciate Dr Xu's highly interesting and important comments.

Potential Conflicts of Interest

None of the authors have any affiliations with commercial firms whose products or services are utilized in this study.

Comments

© 2024 American Neurological Association.

https://onlinelibrary.wiley.com/share/FDVVB3J5ZU64HXUUDAJ4?target=10.1002/ana.27064

Publication Title

Annals of Neurology

DOI

https://doi.org/10.1002/ana.27064

Academic Level

faculty

Mentor/PI Department

Neurology

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