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Abstract
Background Balloon guide catheter (BGC) in stent retriever based thrombectomy (BGC+SR) for patients with large vessel occlusion strokes (LVOS) improves outcomes. It is conceivable that the addition of a large bore distal access catheter (DAC) to BGC+SR leads to higher efficacy. We aimed to investigate whether the combined BGC+DAC+SR approach improves angiographic and clinical outcomes compared with BGC+SR alone for thrombectomy in anterior circulation LVOS.
Methods Consecutive patients with anterior circulation LVOS from June 2019 to November 2020 were recruited from the ROSSETTI registry. Demographic, clinical, angiographic, and outcome data were compared between patients treated with BGC+SR alone versus BGC+DAC+SR. The primary outcome was first pass effect (FPE) rate, defined as near complete/complete revascularization (modified Thrombolysis in Cerebral Infarction (mTICI) 2c–3) after single device pass.
Results We included 401 patients (BGC+SR alone, 273 (66.6%) patients). Patients treated with BGC+SR alone were older (median age 79 (IQR 68–85) vs 73.5 (65–82) years; p=0.033) and had shorter procedural times (puncture to revascularization 24 (14–46) vs 37 (24.5–63.5) min, p<0.001) than the BGC+DAC+SR group. Both approaches had a similar FPE rate (52% in BGC+SR alone vs 46.9% in BGC+DAC+SR, p=0.337). Although the BGC+SR alone group showed higher rates for final successful reperfusion (mTICI ≥2b (86.8% vs 74.2%, p=0.002) and excellent reperfusion, mTICI ≥2 c (76.2% vs 55.5%, p<0.001)), there were no significant differences in 24 hour National Institutes of Health Stroke Scale score or rates of good functional outcome (modified Rankin Scale score of 0–2) at 3 months across these techniques.
Conclusions Our data showed that addition of distal intracranial aspiration catheters to BGC+SR based thrombectomy in patients with acute anterior circulation LVO did not provide higher rates of FPE or improved clinical outcomes.
- stroke
- thrombectomy
- stent
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Introduction
The ultimate goal of mechanical thrombectomy (MT) in acute ischemic stroke (AIS) is to achieve fast and complete reperfusion (modified Thrombolysis in Cerebral Infarction (mTICI) 2c–3), ideally with a single device pass, an outcome measure that has been referred to as first pass effect (FPE). FPE is an independent predictor of favorable functional outcomes and has therefore been proposed as a new metric for the evaluation of thrombectomy devices and techniques.1 Recent guidelines have recommended the use of stent retrievers (SRs) in patients with acute ischemic stroke due to large vessel occlusion (LVO) on the basis that these were the predominant devices used in the recent MT randomized clinical trials.2–8 However, the evolution of aspiration thrombectomy technology with flexible and highly navigable large bore distal access catheters (DACs) has also resulted in faster and more efficient revascularization and subsequent improved clinical outcomes.9 10 Recently, combined techniques with the use of balloon guide catheter (BGC) with stent retriever (SR) and distal access catheter (DAC) (BGC+DAC+SR) has gained increasing acceptance and has largely replaced the more traditional approaches based on BGC+SR alone. The arrested proximal flow provided by the BGC reduces the risk of distal embolization and embolization to unaffected vascular territories, and has been demonstrated to lead to better angiographic and clinical outcomes.11–23 However, while the cervical flow control might be enough for cases of internal carotid occlusion, it theoretically has more limited efficacy in the setting of middle cerebral artery occlusions due to the continuous antegrade flow provided by the circle of Willis collaterals. In this setting, the addition of intracranial aspiration with DAC may optimize flow control. Furthermore, adding a DAC to an SR may allow better capture of the thrombus by means of mechanical 'pinning' or continuous distal aspiration after SR removal, further diminishing the risk of distal thrombus embolization.
The main techniques of MT implemented clinically include: (i) use of an SR by incorporation of the clot through its struts and withdrawal of the device under flow arrest by a BGC (BGC+SR), (ii) direct aspiration first pass thrombectomy with a large bore aspiration DAC, and (iii) a combination of both, where the SR is usually partially or completely withdrawn into an intracranially placed aspiration catheter (BGC+DAC+SR). Failure of MT is typically related to the inability of effectively removing the thrombus and/or its fragmentation with distal migration.
Theoretically, combined thrombectomy techniques may increase rates of fast and complete recanalization. We sought to investigate whether the combined BGC+DAC+SR approach improves angiographic and clinical outcomes compared with the simpler BGC+SR alone approach for thrombectomy in anterior circulation stroke in the ROSSETI registry.
Materials and methods
The ROSSETTI registry is an ongoing investigator initiated prospective study collecting deidentified demographic, clinical, and procedural variables as well as site adjudicated angiographic and clinical outcomes in AIS consecutive patients treated with MT across 10 comprehensive stroke centers in Spain. The main objective of the ROSSETTI registry is to evaluate the efficacy and safety of the different stent retriever based MT techniques used in AIS patients with anterior circulation LVO strokes (LVOS). The registry started in June 2019 and therefore incorporates the more recent device technology with SRs, including the Trevo, Solitaire, Catch, Aperio, Neva, and Embotrap devices, and intracranial aspiration catheters of up to 0.071 inches (inner diameter). We collected data from June 2019 to November 2020. Inclusion criteria in the current analysis were: age ≥18 years; baseline National Institutes of Health Stroke Scale (NIHSS) score ≥2, documented proximal anterior circulation LVOS (intracranial carotid artery or middle cerebral artery–M1 segment) confirmed on DSA, time from last seen well to treatment up to 24 hours, and premorbid modified Rankin Scale (mRS) score ≤2. The stroke neurology team decided whether or not to administer intravenous thrombolysis based on standard indications according to institutional guidelines. The type of thrombectomy approach was mainly dependent on the institution's or physician’s preferences and was not driven by patient or vascular specific characteristics. All participating centers received institutional review board approval from their respective institutions, and patients or representatives signed informed consent. Prospectively gathered data were then retrospectively analyzed. Only CE marked SR and DAC were included, with the specific device choice at the discretion of the operator. Qualifying patients were categorized according to the use of BGC+SR alone versus BGC+DAC+SR techniques (figure 1).
Balloon guiding catheter approaches.
The primary clinical outcome was the rate of functional independence (mRS score ≤2) at 3 months. The primary technical outcome was the rate of FPE, defined as achieving near complete/complete revascularization (modified Thrombolysis in Cerebral Infarction (mTICI) 2c–3) after a single treatment pass.
Secondary outcomes included 24 hour NIHSS score, symptomatic intracranial hemorrhage (sICH, according to ECCASS-II definition),24 final number of passes, modified FPE (defined as mTICI 2b–3 after a single treatment pass), successful (mTICI 2b–3) and complete (mTICI 2c–3) reperfusion at the end of the procedure, and 90 day mortality. Groin puncture to first run, first run to final revascularization (MT time), and groin puncture to revascularization were also compared across both groups. Reperfusion scores, sICH evaluation, and clinical outcome were self-adjudicated by experienced neurointerventionalists and neurologists.
Statistical analysis
Quantitative variables are reported as medians (IQR) and nominal variables as number (percentage). Demographic, clinical data, procedure details, angiographic outcomes, and clinical outcomes were compared between the two groups. The χ2 test and Fisher's exact test were used for categorical variables and the Student’s t test/F test for continuous variables. A p value <0.05 was considered to be statistically significant. All statistical analyses were performed using R (V.3.6.1).
Results
A total of 401 patients (median age 77 (IQR 67–85) years; 53.4% women) were included in the analysis. Median (IQR) presenting NIHSS score and Alberta Stroke Program Early CT Score were 18 (IQR 13–21) and 8 (7–10), respectively. In all patients, BGC and SR were used. The BGC+SR alone group encompassed 273 (66.6%) out of the 401 patients. Table 1 outlines the characteristics of the study cohort and online supplemental figure 1 shows the crossover between the groups. The BGC+SR alone group had a higher median age (79 (IQR 68–85) vs 73.5 (65–82) years; p=0.033), lower use of intravenous tissue plasminogen activator (16.1% vs 42.2%; p<0.001), and higher frequency of general anesthesia utilization (44% vs 12.5%; p<0.001) compared with the BGC+DAC+SR group. Online supplemental table 1 summarizes the rate of each MT approach according to the recruiting centers.
Supplemental material
Sample characteristics according to balloon guiding catheter techniques in patients with anterior proximal circulation stroke as firstline thrombectomy
The BGC+SR alone approach had a shorter median MT time (17 (9–34) vs 26 (16–50.5) min; p<0.001) and groin puncture to revascularization time (24 (14–46) vs 37 (24.5–63.5) min; p<0.001). The FPE rate (BGC+SR alone 52% vs BGC+DAC+SR 46.9%), mFPE (BGC+SR alone 60.1% vs BGC+DAC+SR 54.7%), and final number of passes were comparable among the two groups. Even though the BGC+SR alone approach showed higher rates of both successful revascularization (mTICI ≥2b, 86.8% vs 74.2%; p=0.002) and excellent revascularization (mTICI ≥2c, 76.2% vs 55.5%; p<0.001) at the end of the procedure, there were no significant differences in NIHSS scores at 24 hours, sICH rates, functional independence (mRS ≤2), or mortality at 3 months. The online supplemental table 2 shows the type and size of the devices used.
Discussion
The current interim analysis of the ongoing ROSSETTI registry was designed to compare the performance across two commonly employed thrombectomy techniques: BGC+DAC+ SR versus the simpler BGC+SR alone approach. There are potential advantages of combining local aspiration with an SR. The addition of the continuous and localized suction and the mechanical 'pinning' effect provided by the DAC should, at least theoretically, enhance clot engagement. Moreover, the DAC optimizes the retrieval forces by better aligning the vector of movement into a more desirable angle. These techniques have achieved improved successful final recanalization (mTICI ≥2b) rates, according to previous retrospective studies.22 23 25 26 The rate of FPE (TICI 3) has been shown to be 43–72% of cases, depending on the technique. In our analysis, we found that the BGC+DAC+SR and BGC+SR alone techniques yielded similar rates of FPE (46.9% vs 52%, respectively). Likewise, there were no significant differences in mFPE or number of device passes. Despite the fact that procedure times were shorter and the rates of both successful and excellent recanalization were higher with the BGC+SR alone approach, clinical outcomes at 3 months were comparable for the two techniques. However, further re-evaluation of the ROSSETTI registry after inclusion of more patients may show a clinical benefit in the BGC+SR cohort due to the higher rate of good and excellent revascularization at the end of the procedure versus the BGC+DAC+ SR group (86.8% vs 74.2% and 76.2% vs 55.5%, respectively). Our overall results are in alignment with the recent ASTER 2 trial27 and add to the body of literature questioning the advantage of the combined BGC+DAC+SR approach, at least as a firstline modality.
Improvements in device technology have increased the rates of recanalization and subsequent functional clinical outcomes. However, in the clinical real world there is uncertainty about which frontline endovascular strategies should be adopted to treat acute stroke patients with LVO in order to optimize reperfusion and clinical outcome. Recent evidence has shown, for instance, no significant differences in the rates of recanalization and good outcomes at 3 months between aspiration thrombectomy and SR techniques.28 In a recent survey, 40% of neurointerventionalists reported aspiration thrombectomy with DAC as frontline therapy followed by nearly 28% for combined DAC+SR, and BGC+SR used by approximately 23%.29 Nearly two-thirds of respondents indicated an increase in MT indications, treating older patients, milder strokes, and/or providing treatment in the late window.30 Determining the optimal technique for MT would be of the utmost importance in this scenario with incremental numbers of patients.
Proximal flow arrest with BGC has been shown to reduce the number and size of distal emboli.28 Overall, in previous studies, BCG has been associated with shortened procedure time, a higher rate of FPE, better clinical outcomes, and lower risk of mortality.11–23 However, while BGC use is more common in SR mediated thrombectomy, the potential benefit of simultaneously use of large bore DAC for intracranial aspiration remains unclear. Distal aspiration may increase the suction effect by reducing the effect of collateral flow through ophthalmic, anterior cerebral, and posterior communicating arteries, which may decrease the aspiration effect in the BGC only method.
Clot retrieval combined with the distal aspiration technique can be performed through a large bore DAC positioned with its tip intracranially at the proximal clot interface (aspiration-retriever technique for stroke (ARTS), also previously referred to as Solumbra technique). Using the ARTS technique, TICI 3 recanalization was achieved in 54.7% of patients. The authors reported an overall successful revascularization rate (TICI ≥2b) of 97.6% of cases.25 In our study, final revascularization, according to mTICI ≥2b, was 93.6% for the BGC+SR alone group and 90.6% for the BGC+DAC+SR group. Combined techniques with the use of BGC plus distal aspiration and SR, as in the SAVE (stent retriever assisted vacuum locked extraction) technique, achieved FPE reperfusion in 23 of 32 patients (72%), resulting in a good clinical outcome (mRS 0–2) in 59% of patients.26 Despite these initially promising results, our study failed to demonstrate any clinical benefits in combining contact aspiration with SR based thrombectomy in anterior circulation LVOS when BGC was universally used.
The study has some limitations. The nature of the registry was non-randomized and there was no independent adjudication of the clinical outcome and angiographic results for each patient. The fact that different types and sizes of stent retrievers and aspiration catheters were used (online supplemental table 2), at variable positions, is a potential bias. Nevertheless, all thrombectomy devices used were the latest generation. Another possible limitation is that there were some imbalances between the two groups concerning the rate of intravenous thrombolysis and use of general anesthesia. Notably, the choice of the firstline endovascular strategy was determined by the treating neurointerventional team. Therefore, we must acknowledge that the operator’s proficiency with the different techniques might have served as a confounder. One of the concerns with using the combined technique is the higher complexity of the procedure which can increase procedure time. Despite the fact that shorter times for MT and from groin puncture to revascularization were seen in the BGC+SR alone group, the time from groin puncture to first run was similar between cohorts. This might indicate that the experience of the different neurointerventionalists may be comparable. Neither imaging data nor thrombus histology were available to further characterize the relationship of reperfusion with thrombus characteristics.
Conclusion
Our data showed that the addition of intracranial aspiration catheters to BGC+SR based thrombectomy in patients with acute anterior circulation LVO did not result in higher rates of FPE or in improved clinical outcomes. Given the reduced procedural time associated with BGC+SR alone along with the overall comparable angiographic and functional outcomes across both techniques, an initial attempt with BGC+SR without DAC may be a more sensible option, mostly when considering the added device costs
Supplemental material
Ethics statements
Patient consent for publication
Ethics approval
ROSSETTI Registry has been approved by the IEC of the corresponding author's institution (HCB/2019/0152).
Acknowledgments
Lydia Gregg, MA, CMI, FAMI, Associate Professor, Medical Illustrator, Department of Art as Applied to Medicine and Division of Interventional Neuroradiology, Johns Hopkins University School of Medicine.
References
Supplementary materials
Supplementary Data
This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.
Footnotes
Twitter @jordiblascoa, @AntonioLR81, @manumoreu, @oscarsabino
Collaborators ROSSETTI Group: González Díaz E, Labayen Azparren I, Fondevila Monsó J, Manso del Caño X, Vega P, Murias E, Jiménez Pérez JM, Chaviano Grajera J, Castañon Apilanez M, Lopez Cancio E, Oteros Fernández R, Jiménez-Gómez E, Bravo Rey I, Romero Saucedo V, Delgado Acosta F, San Román L, López-Rueda A, Macho J, Macías N, Zarco F, Renú Jornet A, Blasco J, Moreu M, Perez-García C, Rosati S, López-Frias A, Chirife Chaparro O, Aixut S, Rodríguez Caamaño I, de Miquel Miquel MA, Barranco Pons R, Aja Rodríguez L, Cuba Camasca V, Terceño M, Bashir S, Paul L, Werner M, Castaño C, Remollo S, Pumar JM, Mosqueira A, Aguilar Tejedor Y, Cubillo Prieto D, Bravo de Laguna Toboada A, Méndez JC, Bermúdez-Coronel I, Fandiño E, Gallego Leon JI, López Hernandez N, Moliner S, Rayon JC.
Contributors All authors contributed equally to the design, writting, and reviewing of the manuscript.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial, or not-for-profit sectors.
Competing interests RGN reports consulting fees for advisory roles with Anaconda, Biogen, Cerenovus, Genentech, Imperative Care, Medtronic, Phenox, Prolong Pharmaceuticals, and Stryker Neurovascular, and stock options for advisory roles with Astrocyte, Brainomix, Cerebrotech, Ceretrieve, Corindus Vascular Robotics, Vesalio, Viz-AI, and Perfuze.
Provenance and peer review Not commissioned; externally peer reviewed.
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