Mechanical Thrombectomy with the Vecta 46 Catheter: A Safety and Outcome Analysis

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors proposed a retrospective single-center experience of the performance of new intermediate catheter in EVT. 

I have some comments about the data, aiming to improve the paper itself.

1. in the introduction MeVO trials are referred as ongoing, but at least the main three trials have been published and the findings are not positive in general. Then, EVT in primary MeVOs is not recommended
2. I suggest to separate M2 occlusions from MeVo categories, being different the inclusion criteria of LVO and MeVO trials, different the anatomical boundaries of M2 MCA in each trials and different the volume of hypoperfused territory in M2 vs M3-M4 occlusions
3. posterio circulation occlusions should be detailed (VA-BA occlusion is different than P2-P3 PCA occlusion)
4. I am not sure about gouping primary and secundary MeVOs in the same analysis. I understand the small cohort but I think that this issue deserves at least a comment in the discussion
5. Technically feasible and/or technically successful is not equal to clinically significant. I suggest to additionally report the number of patients with mRS 0-1 (or 0-2) (excellent vs good outcome) and the proportion of patients with mRS 6 at 3 months, if any.   

Author Response

in the introduction MeVO trials are referred as ongoing, but at least the main three trials have been published and the findings are not positive in general. Then, EVT in primary MeVOs is not recommended	Thank you for your feedback. We have updated the introduction to discuss the recently concluded DISTAL and ESCAPE-MeVO trials (Lines 59-61).
I suggest to separate M2 occlusions from MeVo categories, being different the inclusion criteria of LVO and MeVO trials, different the anatomical boundaries of M2 MCA in each trials and different the volume of hypoperfused territory in M2 vs M3-M4 occlusions	Thank you for your suggestion. We have separated M2 occlusions from MeVO categories.
posterior circulation occlusions should be detailed (VA-BA occlusion is different than P2-P3 PCA occlusion)	Posterior circulation occlusions have been expanded in detail in both the table 2 and figure 1
I am not sure about gouping primary and secundary MeVOs in the same analysis. I understand the small cohort but I think that this issue deserves at least a comment in the discussion	We appreciate and understand your concerns. We have added this important limitation to our discussion (Lines 249-251).
Technically feasible and/or technically successful is not equal to clinically significant. I suggest to additionally report the number of patients with mRS 0-1 (or 0-2) (excellent vs good outcome) and the proportion of patients with mRS 6 at 3 months, if any.	Thank you for this comment. Unfortunately, our center has many transfer patients who do not follow up, after discharge, so we were unable to achieve a reasonable number of followup mRS values. We now acknowledge this limitation in the discussion (line 253-255) and have removed this variable from the methods.

Reviewer 2 Report

Comments and Suggestions for Authors

The authors present a single center, retrospective cohort study of mechanical thrombectomy procedures assessing the results of the Vecta46 catheter.   The authors find no significant differences in the overall recanalization rates or times.  However, there is a statistically significant difference in the number of attempts needed for aspiration.  Regardless of these findings, it is very difficult to assess any significance from this trial given the lack of information provided on technique and reasons for choice of catheter use.  Without this procedural description, particularly in a single-center study with low numbers of usage, it is impossible to assess whether any true significance is reasonable to conclude.  Further, the overall trial (assessment of a single manufacturer catheter) fails to provide significant scientific merit (i.e. is this an attempt to assess MeVO results, use of smaller aspiration catheters vs. larger catheters, etc.).   

Author Response

Without this procedural description, particularly in a single-center study with low numbers of usage, it is impossible to assess whether any true significance is reasonable to conclude.  Further, the overall trial (assessment of a single manufacturer catheter) fails to provide significant scientific merit (i.e. is this an attempt to assess MeVO results, use of smaller aspiration catheters vs. larger catheters, etc.).

We have adjusted the final sentence in our introduction to clarify the aim of this project is specifically to compare Vecta 46, with its unique size (lines 86-89).

Reviewer 3 Report

Comments and Suggestions for Authors

Overall Assessment

This is a timely, clinically relevant single-center retrospective study addressing a genuine gap in the literature on intermediate aspiration catheters for mechanical thrombectomy. The topic is appropriate for the journal and the writing is generally clear. However, several methodological and structural weaknesses require substantive revision before this manuscript is suitable for publication.

 

The introduction is well-structured, progressing logically from established LVO thrombectomy evidence to the emerging MeVO landscape, and situating the Vecta 46 appropriately within that context. The clinical motivation is clearly articulated.

Baseline characteristics appear well-matched between groups and are clearly tabulated. The primary outcomes are transparently reported with p-values in the results section.

The discussion correctly identifies the key novel finding — that Vecta 46 requires more aspiration attempts and has higher SR failure rates — and contextualizes this within catheter design principles. The limitation paragraph is honest and appropriately cautious.

 

 

 

Critical concerns:

 1.The final sentence of the introduction ("Herein, we demonstrate that MT utilizing Vecta 46 is safe and efficacious for both LVO and MeVO strokes") pre-empts the results and is inappropriate for an empirical study. The introduction should end with aims and hypotheses, not conclusions.

The DISTAL and ESCAPE-MeVO trials are mentioned here without citations, which is an important omission given they are the primary ongoing trials the study situates itself within.

 

 

2.The Results section (Section 3) uses subsection numbering "4.1" and "4.2" — a clear copy-paste error that must be corrected throughout

.

3. Table 3 reports procedure duration (57.8 ± 43.92 and 47.6 ± 26.4) without specifying units — presumably minutes, but this must be stated explicitly in the table, not assumed from the text.

 

4.Follow-up outcomes absent. The methods section defines follow-up mRS as a planned outcome, but no follow-up mRS data appear in the results — only discharge mRS is reported. Either follow-up data should be presented or the methods section should be amended to remove this as an outcome.

 

5.No multivariate analysis. Given that Vecta 46 was more likely to be used in M2/M3 occlusions (41% vs 21% for M2), the occlusion location distribution, while not reaching significance, is clinically imbalanced. Outcomes such as recanalization success and ICH should be adjusted for occlusion location and technique used, even in a sensitivity analysis.

 

6.Figure 1 is unreadable. The bar charts in Figure 1 (A and B) are reproduced at very low resolution. Axis labels, legend text, and bar annotations are illegible. This figure must be resubmitted at a minimum of 300 DPI with clearly readable labels. This is a fundamental quality issue.

7.Legend description mismatch. The figure legend refers to "non-Vecta 46 vs Vecta 46 group" but also lists "All" as a separate category in the chart. The "All" category is neither defined in the methods nor explained in the legend.

 

8.In the discussion part of the manuscript, the term “ non-inferior “ is repeatedly used (e.g., lines 200, 224, 227), but a formal non-inferiority analysis with a pre-specified margin was never conducted. Failing to reach statistical significance on underpowered tests is not equivalent to demonstrating non-inferiority. This language must be replaced with more measured phrasing such as "no statistically significant difference was detected."

 

9.The citation supporting the claim that "similar functional outcomes reflect non-inferior time to revascularization" (line 212) is a collateral flow study, not a direct demonstration of this mechanistic link in the context of catheter comparison. A more appropriate reference should be identified or the inference reframed.

 

10."Secondary inclusion" on line 108 should read "secondary occlusion."

 

11.Abbreviations for TICI, NIHSS, and mRS are used in the abstract before being defined.

 

 

The study addresses an important clinical question and the core data are valuable, but the manuscript requires substantial revision addressing: the underpowered sample and absence of confidence intervals; the unreadable Figure 1; the inappropriate use of "non-inferiority" language; the inadequate discussion of the ICH signal; correction of multiple numbering and arithmetic errors; and updated guideline citations. The authors should also strongly consider adding a multivariate analysis adjusting for occlusion location

Author Response

The final sentence of the introduction ("Herein, we demonstrate that MT utilizing Vecta 46 is safe and efficacious for both LVO and MeVO strokes") pre-empts the results and is inappropriate for an empirical study. The introduction should end with aims and hypotheses, not conclusions.	This sentence has been removed to make more realistic claims.
The DISTAL and ESCAPE-MeVO trials are mentioned here without citations, which is an important omission given they are the primary ongoing trials the study situates itself within.	Thank you for finding this error. Appropriate discussion of the trials has been added with citations to in line 61.
The Results section (Section 3) uses subsection numbering "4.1" and "4.2" — a clear copy-paste error that must be corrected throughout	Thank you for finding this error. We have fixed this issue in lines 131, 153, and 181.
Table 3 reports procedure duration (57.8 ± 43.92 and 47.6 ± 26.4) without specifying units — presumably minutes, but this must be stated explicitly in the table, not assumed from the text.	Thank you for finding this error. We have added a (minutes) description to table .
Follow-up outcomes absent. The methods section defines follow-up mRS as a planned outcome, but no follow-up mRS data appear in the results — only discharge mRS is reported. Either follow-up data should be presented or the methods section should be amended to remove this as an outcome.	Thank you for this comment. Unfortunately, our center has many transfer patients who do not follow up, after discharge, so we were unable to achieve a reasonable number of followup mRS values. We now acknowledge this limitation in the discussion (line 253-255) and have removed this variable from the methods.
No multivariate analysis. Given that Vecta 46 was more likely to be used in M2/M3 occlusions (41% vs 21% for M2), the occlusion location distribution, while not reaching significance, is clinically imbalanced. Outcomes such as recanalization success and ICH should be adjusted for occlusion location and technique used, even in a sensitivity analysis.	Please see the multivariate analysis in the supplemental. The trend in no significant differences between the groups persists when controlling for vessel location and secondary thrombus aspirated.
Figure 1 is unreadable. The bar charts in Figure 1 (A and B) are reproduced at very low resolution. Axis labels, legend text, and bar annotations are illegible. This figure must be resubmitted at a minimum of 300 DPI with clearly readable labels. This is a fundamental quality issue.	The figure has been updated to a higher resolution.
Legend description mismatch. The figure legend refers to "non-Vecta 46 vs Vecta 46 group" but also lists "All" as a separate category in the chart. The "All" category is neither defined in the methods nor explained in the legend.	Thank you for this comment to increase our clarity. The category has been renamed in the figure to “non-Vecta 46.”
In the discussion part of the manuscript, the term “ non-inferior “ is repeatedly used (e.g., lines 200, 224, 227), but a formal non-inferiority analysis with a pre-specified margin was never conducted. Failing to reach statistical significance on underpowered tests is not equivalent to demonstrating non-inferiority. This language must be replaced with more measured phrasing such as "no statistically significant difference was detected."	Thank you for your feedback. We have changed the language to be more conservative in lines 197, 199-201, 226, and 241.
The citation supporting the claim that "similar functional outcomes reflect non-inferior time to revascularization" (line 212) is a collateral flow study, not a direct demonstration of this mechanistic link in the context of catheter comparison. A more appropriate reference should be identified or the inference reframed.	Thank you for your comment. We have replaced the citation to reference the MR CLEAN results that time to revascularization correlates with functional outcomes (lines 198, 199)
"Secondary inclusion" on line 108 should read "secondary occlusion."	We apologize for this error. It has been fixed in the updated manuscript. (line 108)
Abbreviations for TICI, NIHSS, and mRS are used in the abstract before being defined.	We do not use these abbreviations in the abstract.
Academic Editor Comments: 1. Please describe the clinical scenarios in which the AXS Vecta 46 Intermediate Catheter was selected. Was the selection determined by the target vessel size? 2. How many operators were involved in performing the procedures? 3. The manuscript suggests that a higher number of aspiration attempts and secondary thrombus aspiration. Does this imply that the AXS Vecta 46 Intermediate Catheter is less effective (i.e., requires more procedural attempts) and may contribute to thrombus migration necessitating additional aspiration?	Thank you for your comments. 1. Vecta 46 catheter choice was determined by operator preference for significant navigation to medium vessels based on angiography. 2. Three different operators performed the procedures (added in line 93). 3. Please see lines 241-245. Although there were no statistically significant differences in primary or secondary occlusion location between Vecta 46 and non-Vecta 46 thrombectomies, Vecta 46 was used to aspirate secondary occlusions more often, likely due to versatility and trackability in navigating distal vasculature while retaining sufficient aspiration force to provide good results for thrombectomy. This rationale has been added to lines 93-95.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have presented an updated revision to their article demonstrating the performance of the Vecta46 aspiration catheter.  Again, the manuscript is well written and presented clearly.  The single center nature of the study and non-systematic utilization of the device draws away from the merit.  Further, a manuscript detailing one company's product profile compared to others fails to show significant scientific rigor.  However, with the continued expanded profile of these devices, there is little firm data to separate performances and inform hospitals or physicians on which device to use.  By demonstrating a decreased combined performance of these catheters with stent retriever use the manuscript does allow for some differentiation.