Technical and Clinical Outcomes at a Thrombectomy-Capable Stroke Center in Poland in the Context of the Center’s Growing Experience, Expanding Treatment Guidelines and the Rise in Acute Ischemic Stroke Patient Volume: A Comparative Analysis of Initial and Subsequent Endovascular Procedures

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This revised manuscript presents a thorough and clinically relevant analysis of a newly established Thrombectomy-Capable Stroke Center and addresses important questions regarding learning curves, workflow models, and expanded treatment indications. The authors are commended for the comprehensive dataset, clear stratification of patient cohorts, and benchmarking against national registry data.

To further strengthen the manuscript, the authors are encouraged to:

1. Add a clearly delineated limitations paragraph in the Discussion, explicitly acknowledging the retrospective, single-center design, lack of multivariable adjustment, and limited sample size in some subgroups.

2. Slightly tone down causal or non-inferiority language where differences are statistically non-significant, emphasizing the observational nature of the findings.

3. Improve clarity and consistency in terminology (e.g., drip-and-ship, IVT/rtPA) and address minor grammatical and stylistic issues to enhance readability.

4. Clarify early in the Methods that “door time” refers to admission at the first stroke center, particularly for drip-and-ship patients, to avoid misinterpretation of time metrics.

Overall, the study provides valuable real-world evidence supporting the role of TCSCs in contemporary stroke care and, after minor revisions, is suitable for publication.

Comments on the Quality of English Language

The manuscript is generally understandable and uses appropriate scientific terminology. However, the English language would benefit from minor professional editing, particularly to improve sentence structure, reduce overly long or complex sentences, and correct occasional grammatical and stylistic inconsistencies. These issues do not impede comprehension but addressing them would significantly enhance clarity and readability.

Author Response

Dear Editors and Reviewers,

 

We express our gratitude for your interest in our publication and for the insightful comments provided during the review process. We have carefully considered all of these valuable suggestions and have made the recommended revisions to the manuscript. Below, we address each reviewer's comments.

 

Response to Reviewer 1:

Ad 1. “The English could be improved to more clearly express the research”.

The English was improved with professional editiorial help with MDPI Author’s services.

Ad 2. “This revised manuscript presents a thorough and clinically relevant analysis of a newly established Thrombectomy-Capable Stroke Center and addresses important questions regarding learning curves, workflow models, and expanded treatment indications. The authors are commended for the comprehensive dataset, clear stratification of patient cohorts, and benchmarking against national registry data”.

 

We greatly appreciate the overall summary and feedback on our manuscript.

Ad 3. “Add a clearly delineated limitations paragraph in the Discussion, explicitly acknowledging the retrospective, single-center design, lack of multivariable adjustment, and limited sample size in some subgroups”.

The paragraph has been added to manuscript.

Ad 2. “Slightly tone down causal or non-inferiority language where differences are statistically non-significant, emphasizing the observational nature of the findings.”

The manuscript has been updated with these changes, as suggested above.

Ad 3. “Improve clarity and consistency in terminology (e.g., drip-and-ship, IVT/rtPA) and address minor grammatical and stylistic issues to enhance readability.”

The manuscript has been updated with those corrections were made, as suggested.

Ad 4. Clarify early in the Methods that “door time” refers to admission at the first stroke center, particularly for drip-and-ship patients, to avoid misinterpretation of time metrics.

The clarification has been added to manuscript.

Kind regards,

Artur Dziadkiewicz

on behalf of all authors.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The study addresses key organizational issues in stroke care: implementation of new centers, the learning curve, transition to a «drip-and-ship» model, and extension of the treatment time window. The work provides real-world, data about the challenges and successes of launching a new service, which is valuable for other institutions planning similar projects.

- It is necessary to clearly state whether the study was approved by an ethics committee and whether informed consent was obtained from patients.

- The rationale for dividing into the first 100 and subsequent 150 patients (May 2023) is explained (new operator, 24/7 service). However, the presented results lack a direct comparison of the outcomes achieved by the two different operators. All analyses are between patient groups, not between operators. To study the «learning curve of the new operator» a direct comparison of his/her first, say, 50 cases with subsequent 50 cases, or with a similar volume by the experienced operator, would strengthen the work.

- All presented comparisons are univariate. Logistic regression analysis was not performed to identify independent predictors of good functional outcome (mRS 0-2) or successful recanalization, adjusting for age, baseline NIHSS, occlusion site etc. This diminishes the scientific value of the work.

- A substantial part of the discussion is devoted to a review of literature not directly linked to the interpretation of the authors' own data. It is better to focused on explaining the authors' own results, their alignment with or contradiction to existing literature, and hypothesis generation.

- Authors need to check punctuation, especially before and after links.

Author Response

Dear Editors and Reviewers,

 

We express our gratitude for your interest in our publication and for the insightful comments provided during the review process. We have carefully considered all of these valuable suggestions and have made the recommended revisions to the manuscript. Below, we address each reviewer's comments.

Response to Reviewer 2:

We greatly appreciate all comments and the overall summary on our manuscript.

Ad 1.  “It is necessary to clearly state whether the study was approved by an ethics committee and whether informed consent was obtained from patients.”

This clarification has been added to manuscript, before reference section.

Ad 2. “The rationale for dividing into the first 100 and subsequent 150 patients (May 2023) is explained (new operator, 24/7 service). However, the presented results lack a direct comparison of the outcomes achieved by the two different operators. All analyses are between patient groups, not between operators. To study the «learning curve of the new operator» a direct comparison of his/her first, say, 50 cases with subsequent 50 cases, or with a similar volume by the experienced operator, would strengthen the work”.

This comment is highly appreciated. The primary objective of the study was to showcase general findings and compare the initial and later groups of patients treated in our TCSC. A more detailed analysis of the learning curve and the varying experiences of operators would be more compelling if more operators were compared. Therefore, we plan to conduct such a study in collaboration with other centers, considering this publication as the initial step in this comparison.

Ad 3. “All presented comparisons are univariate. Logistic regression analysis was not performed to identify independent predictors of good functional outcome (mRS 0-2) or successful recanalization, adjusting for age, baseline NIHSS, occlusion site etc. This diminishes the scientific value of the work.”

Given the significance of this state, we opted to focus solely on univariate comparisons due to the large amount of statistically analyzed data and tables, particularly since the study is conducted at a single center. In future multi-center articles, we plan to incorporate multivariate analysis and regression for comparison.

Ad 4. “A substantial part of the discussion is devoted to a review of literature not directly linked to the interpretation of the authors' own data. It is better to focused on explaining the authors' own results, their alignment with or contradiction to existing literature, and hypothesis generation”.

The discussion section has been upgraded and these comparative information has been added. The initial paragraphs of the Discussion section were dedicated to summarizing the results and setting the stage for the subsequent presentation of additional information and comments drawn from the literature. This is then presented in a step-by-step manner, connected to the results previously discussed.

Ad 5. “Authors need to check punctuation, especially before and after links.”

These corrections have been added to the manuscipt.

Kind regards,

Artur Dziadkiewicz

on behalf of all authors.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

In this study, the effect of thrombectomy capable stroke centers (TCSC) is investigated on the patient population with acute stroke due to large vessel occlusion. A retrospective study is conducted with a patient population of 250 from August 2020 to May 2025. The primary objective is to examine the practice changes and development of newly established thrombectomy capable stroke centers. Using the retrospective data, patients admitted directly to a TCSC and via the drip-ship-model are compared. Another comparison focused on the patients treated within a 6-hour early time window and within an extended time window of 6-24 hours. Time intervals and procedural aspects indicated the role of enhanced operator experience. This study shows the importance of optimized work flow and positive impact of TCSC for acute ischemic stroke patients.  In my opinion, the methods and results are properly defined and the paper includes the necessary details. However, I recommend the following revisions in order to improve the clarity of the manuscript: 

1. For the subheadings of the abstract, the style provided in the template document should be used. For example, (1) Introduction: ….
2. There are several typos in the document. The paper should be revised to avoid typos.
3. The total population of patients and the number of medical centers can be increased in future papers to understand whether the comparison yields reliable results. This can be stated as a limitation.
4. Instead of “see the table below” at line 127, the table number should be indicated for better readability.
5. The paragraph starting at line 145 seems to have a different font. Please use a single font in the manuscript.
6. In the references part, a tab seems in front of the first reference. The font of references should be the same with text.

Author Response

Dear Editors and Reviewers,

 

We express our gratitude for your interest in our publication and for the insightful comments provided during the review process. We have carefully considered all of these valuable suggestions and have made the recommended revisions to the manuscript. Below, we address each reviewer's comments.

Response to Reviewer 3:

Ad 1. “In my opinion, the methods and results are properly defined and the paper includes the necessary details”.

We are thankful to this statement and all comments and feedback provided.

Ad 2. “For the subheadings of the abstract, the style provided in the template document should be used. For example, (1) Introduction: ….”

This changes have been added to the manuscript.

Ad 2. “There are several typos in the document. The paper should be revised to avoid typos.”

The English was improved with professional editiorial help with MDPI Author’s services.

Ad 3. “The total population of patients and the number of medical centers can be increased in future papers to understand whether the comparison yields reliable results. This can be stated as a limitation”.

The limitations section has been incorporated into the Discussion. As you suggested, exploring future directions for the studies is an excellent idea, and we will aim to collaborate with more stroke centers.

Ad 4. “Instead of “see the table below” at line 127, the table number should be indicated for better readability.”

This sentences have been upgraded, as suggested.

Ad 5. “The paragraph starting at line 145 seems to have a different font. Please use a single font in the manuscript”.

The font has been changed.

Ad 6. “In the references part, a tab seems in front of the first reference. The font of references should be the same with text.”

The change hase been done, as suggested.

Kind regards,

Artur Dziadkiewicz

on behalf of all authors.

Author Response File: Author Response.docx

Reviewer 4 Report

Comments and Suggestions for Authors

The title is too long. Please make it short and catchy. Avoid using country name in the title.

The abstract is too long. Please follow journal’s instructions and curtail it to 250 words.

There is no need to split the abstract into paragraphs.

Keywords are incorrect. Please check from MeSH database.

The last paragraph of the introduction section should be rewritten. Please summarize the gap in published literature and state the need to perform the present study in order to bridge the gap. No need to explain the study in the last paragraph.

How was the sample size calculated?

What can the ideal window time?

What happens if the transfer of the patients is slow?

Are there chances when thrombectomy may be delayed?

What can be ways to train neuro-interventionalists?

How to select specific stroke patients? Do all qualify?

Please add the cost effectiveness as it will benefit future health professionals.

How do the authors compare their treatment protocol with different protocols at other places in the world?

Author Response

Dear Editors and Reviewers,

 

We express our gratitude for your interest in our publication and for the insightful comments provided during the review process. We have carefully considered all of these valuable suggestions and have made the recommended revisions to the manuscript. Below, we address each reviewer's comments.

Response to Reviewer 4:

We greatly appreciate all valuable comments and feedback on our manuscript.

Ad 1. “The title is too long. Please make it short and catchy. Avoid using country name in the title.”

The title succinctly yet thoroughly encapsulates all the key features of the study. We believe it is essential to highlight that the TCSC discussed is situated in Poland and addresses Polish-specific challenges and issues in delivering endovascular stroke therapy to patients.

Ad. 2 “The abstract is too long. Please follow journal’s instructions and curtail it to 250 words. There is no need to split the abstract into paragraphs.”

The abstract has been shortened, as suggested. The abstract has been condensed without sacrificing any of its key elements.

Ad 3. “Keywords are incorrect. Please check from MeSH database.”

The keywords have been updated. They are based also on keywords of Special Issue’s own keywords list.

Ad 4 “The last paragraph of the introduction section should be rewritten. Please summarize the gap in published literature and state the need to perform the present study in order to bridge the gap. No need to explain the study in the last paragraph.”

The primary focus of the concluding paragraph was to outline the study's objectives along with a brief overview of its structure. Additionally, a section addressing the knowledge gap was included.

Ad 5. “How was the sample size calculated?”

The sample under analysis encompasses the entire group of patients who received treatment during the specified period.

Ad 5. “What can the ideal window time?”

The preferred time window of treatment was up to 6 hours. However, due to the well-known saying "time is brain," the procedure's start, known as "groin time," was initiated promptly to avoid any unnecessary delays. With the latest updates to guidelines based on recent clinical trial findings, the time window is no longer the primary factor in making decisions regarding endovascular stroke therapy.

Ad 6. “What happens if the transfer of the patients is slow?”

This question holds significant importance and warrants investigation, particularly in Poland, due to the inadequate transportation system for stroke patients and numerous delays. While some findings are included in our current study, we intend to carry out another study focused on this issue.

Ad 7. “Are there chances when thrombectomy may be delayed?”

Recent research indicates that patients who have experienced a stroke within the last 24 hours may still gain advantages from endovascular treatment and should be evaluated for this type of therapy. There are also some additional tools to assess the infarcted brain tissue or penumbra – like CT perfusion, that we can implemented in selected cases.

Ad 8. “What can be ways to train neuro-interventionalists?”

The research was also carried out to examine the outcomes of neurointerventional training, which was implemented through collaboration between a neurologist and a highly skilled cardiologist with expertise in neuro AngioSuites.

Ad 9. “How to select specific stroke patients? Do all qualify?”

The patient qualification procedures are described in the study: Patients presenting with stroke symptoms and LVO (defined as occlusion of the internal carotid artery; M1 or proximal M2 occlusion of the middle cerebral artery; occlusion of the basilar artery; and, in select cases, occlusion of A1 or A2 of the anterior cerebral artery, vertebral artery, and P1 of the posterior artery) were subjected to endovascular treatment, with or without intravenous thrombolysis (IVT), following an assessment by a stroke or interventional neurologist, radiologist, and interventional cardiologist. Prior to the intervention, all patients underwent plain computed tomography (CT) imaging and computed tomography angiography (CTA). MRI scans and computed tomography perfusion (CTP) were conducted among a select group of patients in cases of extended time window protocols. The early time window and primary MT inclusion criteria were as follows: over 18 years of age, a National Institutes of Health Stroke Scale (NIHSS) score of at least 6 or isolated aphasia, and prior functional independence with a modified Rankin scale of mRS 0-2. Additional criteria for extended time windows were based on the criteria of the Wake-up, Dawn, and Defuse clinical trials – explained in table 1.

Ad 10. “Please add the cost effectiveness as it will benefit future health professionals.”

The information about cos-effectiveness and conclusion that MT is a cost – effective procedure (with reference) have been added to the manuscript.

Ad 11. “How do the authors compare their treatment protocol with different protocols at other places in the world?”

The comparison of protocols is grounded in clinical trial protocols and aligns with Polish national standards for the care of stroke patients.

 

Kind regards,

Artur Dziadkiewicz

on behalf of all authors.

Author Response File: Author Response.docx