2025 Volume 19 Issue 1 Article ID: oa.2025-0099
Objective: In recent years, mechanical thrombectomy and aspiration catheter technology have advanced significantly, with newer aspiration catheters (ACs) featuring larger lumens and improved outcomes. However, the specific features driving these improvements remain unclear. The aim of this study was to compare treatment outcomes between the latest-generation large-bore ACs (LACs) and conventional aspiration catheters (CACs) in patients undergoing mechanical thrombectomy.
Methods: In this retrospective single-center cohort study conducted at the authors’ institution, we analyzed data from patients who underwent mechanical thrombectomy using ACs for internal carotid artery (ICA) or M1 segment middle cerebral artery (M1) occlusions between November 2017 and October 2022. Cases were classified into LAC (inner diameter ≥0.0710 inches) and CAC groups. Patient demographics and procedural features were evaluated, including 1st-pass effect (FPE), catheter-to-vessel match (CVM), and clot contact rates. Group comparisons were performed using the Mann–Whitney U-test or the chi-squared test. Univariate and multivariate logistic regression analyses were conducted for M1 occlusion cases treated with LACs.
Results: The study cohort comprised 159 patients who underwent mechanical thrombectomy using ACs. The FPE success rate was significantly higher in the LAC group (52.8%) than in the CAC group (34.0%). With regard to the occlusion site, this rate was not significantly different between the LAC and CAC groups for ICA occlusions; however, for M1 occlusions, the LAC group demonstrated a significantly higher FPE rate than the CAC group (P = 0.009). CVM and clot contact rates were significantly higher in the LAC group (P = 0.001 and P ≤0.0001, respectively). In the LAC group, both CVM and clot contact were independently associated with FPE success in cases of M1 occlusion (odds ratio, 10.9; 95% confidence interval, 3.3–36.7; P <0.0001; odds ratio, 18.0; 95% confidence interval, 1.9–172.9; P = 0.013, respectively).
Conclusion: LACs yielded significantly better outcomes for M1 occlusions than CACs. The enhanced FPE rate appears attributable to 2 design advantages: increased bore size, which improves CVM, and superior trackability, which enhances clot contact. These findings suggest that, given the vessel diameter variations caused by factors beyond anatomical location, tailoring mechanical thrombectomy methods and device selection to individual vascular anatomy, rather than relying on fixed vessel-based criteria, may improve treatment outcomes.
The efficacy of mechanical thrombectomy (MT) for acute large-vessel occlusion was established in 2016.1) Since then, various techniques, stent retrievers (SRs), and aspiration catheters (ACs) have been developed to improve the odds of achieving the 1st-pass effect (FPE). The FPE is based on evidence that successful recanalization with a single pass of an MT device is an independent predictor of favorable outcomes.2) The proportional increase in suction force with inner luminal area has guided the evolution of ACs toward larger inner diameters (IDs); many current large-bore models in commercial lineups feature IDs exceeding 0.070 inches while maintaining similar outer diameters (ODs). Although favorable clinical results with these large-bore devices have been reported,3,4) few studies have directly compared treatment outcomes between conventional and large-bore ACs.
In this study, we aimed to examine the treatment outcomes of MT procedures using ACs and evaluate the specific characteristics contributing to their proposed advantages. In addition, we aimed to determine whether the latest-generation large-bore ACs (LACs) are associated with improved treatment outcomes compared with conventional ACs (CACs).
This retrospective cohort study was conducted at a thrombectomy-capable center between November 2017 and October 2022. We analyzed data from patients who underwent MT for internal carotid artery (ICA) or M1 segment middle cerebral artery (M1) occlusions. In this study, the ICA was defined as the segment extending from the neck to the terminal portion, while the M1 segment was defined as the segment extending from the bifurcation of the anterior cerebral artery to the curvature of the insular cortex.
Exclusion criteria included cases treated >24 h after symptom onset, procedures concluded with angiography only due to spontaneous recanalization, MT performed solely with an SR, and cases requiring emergent carotid artery stenting or percutaneous transluminal angioplasty/stenting. Patients were classified into 2 groups: those treated with CACs and those treated with LACs.
Endovascular procedureAll procedures were performed under local anesthesia by board-certified neurointerventional specialists using a biplane angiography system (Artis Zee Biplane; Siemens Healthineers, Erlangen, Germany). An 8- or 9-Fr balloon guide catheter (Optimo; Tokai Medical, Aichi, Japan) or an 8-Fr guide catheter (FUBUKI; ASAHI INTECC, Aichi, Japan) was advanced to the internal or common carotid artery. Cerebral angiography was first conducted to confirm the occlusion site and assess vascular access. In angiography, the normally visualized proximal vessel diameter closest to the occlusion site was considered the occluded vessel diameter.
Contact aspiration (CA) with an AC was used as the 1st-line approach (Fig. 1A–1C). When AC navigation was difficult, a microcatheter was advanced across the lesion, and an SR was deployed as an anchor to guide the AC to the occlusion site for clot retrieval using a combined technique (Fig. 1D–1G). For CA, aspiration was applied for 90 s prior to catheter retrieval. In combined technique cases, the SR was retracted into the AC until suction cessation, after which both devices were retrieved together as a unit.
CACs included the 5MAX ACE (distal ID 0.060 inch, OD 1.80 mm; Penumbra, Alameda, CA, USA) and 5MAX ACE68 (distal ID 0.068 inch, OD 2.03 mm; Penumbra). The LAC group used the following devices: SOFIA FLOW Plus (distal ID 0.070 inch, OD 2.10 mm; Terumo Neuro, Tustin, CA, USA), JET 7 (distal ID 0.072 inch, OD 2.16 mm; Penumbra), REACT 71 (distal ID 0.071 inch, OD 2.17 mm; Medtronic, Minneapolis, MN, USA), and AXS Catalyst 7 (ID 0.068 inch, OD 2.08 mm; Stryker Neurovascular, Fremont, CA, USA). For the AC, we selected the one with the largest ID from those with an OD smaller than the occluded vessel diameter. SRs used included Solitaire X or Solitaire Platinum (Medtronic), with size selected on the basis of the vessel diameter.
Data collectionDemographic and clinical data included age, sex, vascular risk factors (hypertension, diabetes mellitus, dyslipidemia, current smoking, and cardiopathy including atrial fibrillation), and pre-stroke antithrombotic medication. Clinical stroke characteristics included baseline National Institutes of Health Stroke Scale (NIHSS) score, diffusion-weighted imaging–Alberta Stroke Program Early CT Score (DWI-ASPECTS), occlusion site, prior use of intravenous tissue-type plasminogen activator (IV-tPA), 1st-line technique, puncture-to-reperfusion time, number of passes, and occluded vessel diameter.
Study definitionsSiphon tortuosity was assessed using the Zhong classification,5) with Types U and S indicating tortuosity and Types C and V indicating no tortuosity. “Catheter-to-vessel match” (CVM) was defined as an AC OD that was 85%–100% of the occluded vessel’s diameter (Fig. 2). For both the CA and combined techniques, “clot contact” was defined as advancement of the AC tip beyond the most distal point reached by the contrast medium in the target occluded vessel.
FPE was defined as near-complete or complete reperfusion (modified Thrombolysis in Cerebral Infarction [mTICI] 2c–3) after a single pass. Successful reperfusion was defined as a final mTICI of 2b–3. Post-procedural CT scans were performed immediately and 24 h after MT to assess intracranial hemorrhage (ICH). Symptomatic ICH was defined as any hemorrhage associated with a ≥4-point increase in NIHSS within 24 h after MT. Moreover, 90-day all-cause and stroke-related mortality rates were recorded.
Statistical analysisData are presented as numbers (%), means ± standard deviations, or medians (interquartile ranges [IQRs]), as appropriate. Baseline characteristics were compared between groups using the Mann–Whitney U-test for continuous variables and the chi-squared test for categorical variables.
To clarify the features of LACs that influence FPE, including trackability, we performed univariate logistic regression analysis for patients with M1 occlusions treated with LACs after navigating the internal carotid artery siphon. Analyzed variables included age, sex, cardiogenic embolism, pre-stroke antithrombotic medication, prior use of IV-tPA, siphon tortuosity, and factors that showed significant differences between the LAC and CAC groups. Variables that were significant in the univariate analysis were included in a multivariate logistic regression model. A P-value of <0.05 was considered statistically significant. Analyses were conducted using JMP version 14.1.0 (SAS Institute, Cary, NC, USA).
EthicsThis study was conducted as a noninterventional, retrospective investigation using anonymized personal data. General consent for the academic use of clinical information was obtained, and an opt-out statement was also made publicly available. The research presented within our submission was approved by the Ethics Institutional Review Board of IMS Tokyo-Katsushika General Hospital (Approval No. 89). This study was conducted in accordance with relevant regulations and guidelines, including the ethical principles for medical research involving human participants outlined in the World Medical Association’s Declaration of Helsinki.
During the study period, 269 MT procedures were performed at our institution, of which 190 targeted the ICA or M1 segment of the middle cerebral artery. A total of 79 cases were excluded for the following reasons: 57 involved more distal M2 or beyond, 21 involved the posterior circulation, and 1 involved the anterior cerebral artery. Additional exclusions included procedures using SR only (n = 10), procedures using an AC with an ID of <0.070 inch in the LAC group (n = 2), procedures that concluded with angiography alone due to spontaneous recanalization (n = 4), and cases treated >24 h after symptom onset (n = 2). Emergency carotid artery stenting (n = 8) and percutaneous transluminal angioplasty with stenting (n = 5) were also excluded. The final study cohort comprised 159 patients who underwent MT using ACs. The median age was 79 (IQR, 73–84) years, and 77 (48.4%) patients were women. The median NIHSS score at presentation was 19 (IQR, 14–23), and the median DWI-ASPECTS was 8 (IQR, 6–10). Of these, 53 patients were treated with CACs (22 ICA, 31 M1), and 106 were treated with LACs (31 ICA, 75 M1).
Procedural characteristicsThe CACs used were 5MAX ACE (Penumbra) in 5 cases (9.4%) and 5MAX ACE68 (Penumbra) in 48 cases (90.6%). The LACs used were SOFIA Flow Plus (Terumo Neuro) in 14 cases (13.2%), AXS Catalyst 7 (Stryker Neurovascular) in 3 cases (2.8%), JET 7 (Penumbra) in 11 cases (10.4%), and React 71 (Medtronic) in 78 cases (73.6%). Patient demographics are presented in Table 1. The CAC and LAC groups exhibited no significant differences in baseline characteristics, including NIHSS score and DWI-ASPECTS. For procedural features, there were no significant differences in the procedure time, number of passes, or occluded vessel diameter. However, CVM and clot contact rates were significantly higher in the LAC group than in the CAC group. The FPE success rate was significantly higher in the LAC group (52.8%) than in the CAC group (34.0%). Considering the occlusion site, this rate was not significantly different between groups for ICA occlusions; however, for M1 occlusions, the FPE success rate was significantly higher in the LAC group (60.0%) than in the CAC group (32.3%). Final mTICI 2b–3 was achieved in 96.2% of CAC cases and 99.1% of LAC cases, indicating a nonsignificant difference. In terms of safety, there were no significant differences in the rates of any ICH, symptomatic ICH, or mortality between the groups.
| Overall | CAC | LAC | P-value | |
|---|---|---|---|---|
| Demographics | ||||
| No. of patients, n (%) | 159 | 53 (33.3) | 106 (66.7) | |
| Age (years), median (IQR) | 79 (73–84) | 78 (69–84) | 79.5 (73–85) | 0.244 |
| Female, n (%) | 77 (48.4) | 24 (45.3) | 53 (50.0) | 0.575 |
| Clinical and imaging features | ||||
| Hypertension, n (%) | 121 (76.1) | 40 (75.5) | 81 (76.4) | 0.895 |
| Diabetes mellitus, n (%) | 43 (27.0) | 13 (24.5) | 30 (28.3) | 0.614 |
| Dyslipidemia, n (%) | 70 (44.0) | 26 (49.1) | 44 (41.5) | 0.366 |
| Current smoking, n (%) | 33 (20.8) | 12 (22.6) | 21 (19.8) | 0.678 |
| Pre-stroke antithrombotic medication, n (%) | 56 (35.2) | 20 (37.7) | 36 (34.0) | 0.639 |
| NIHSS score at admission, median (IQR) | 19 (14–23) | 18 (12–23) | 19 (14–24) | 0.134 |
| DWI-ASPECTS at admission, median (IQR) | 8 (6–10) | 9 (6–10) | 8 (6–9) | 0.154 |
| Site of occlusion | 0.122 | |||
| ICA, n (%) | 53 (33.3) | 22 (41.5) | 31 (29.3) | |
| M1, n (%) | 106 (66.7) | 31 (58.5) | 75 (70.8) | |
| Etiology of occlusion | 0.196 | |||
| Cardiogenic embolism, n (%) | 125 (78.6) | 37 (69.8) | 88 (83.0) | |
| Arteriosclerosis, n (%) | 18 (11.3) | 9 (17.0) | 9 (8.5) | |
| Embolic stroke of undetermined source, n (%) | 13 (8.2) | 5 (9.4) | 8 (7.5) | |
| Other, n (%) | 3 (1.9) | 2 (3.8) | 1 (0.6) | |
| Procedural features | ||||
| IV-tPA, n (%) | 5 (3.1) | 4 (7.8) | 1 (0.9) | 0.025 |
| Arterial puncture to reperfusion time (min), median (IQR) | 42 (26–65) | 44 (30–70.5) | 39 (24–56.5) | 0.13 |
| Number of passes, median (IQR) | 1 (1–2) | 2 (1–2) | 1 (1–2) | 0.366 |
| 1, n (%) | 81 (50.9) | 21 (39.6) | 60 (56.6) | |
| 2, n (%) | 47 (29.6) | 25 (47.2) | 22 (20.8) | |
| >2, n (%) | 31 (19.5) | 7 (13.2) | 24 (22.6) | |
| 1st line contact aspiration, n (%) | 84 (52.8) | 12 (22.6) | 72 (67.9) | <0.0001 |
| FPE (mTICI 2c–3), n (%) | 74 (46.5) | 18 (34.0) | 56 (52.8) | 0.025 |
| In ICA occlusion, n (%) | 19 (35.8) | 8 (36.4) | 11 (35.5) | 0.948 |
| In M1 occlusion, n (%) | 55 (51.9) | 10 (32.3) | 45 (60.0) | 0.009 |
| Final mTICI ≥2b, n (%) | 156 (98.1) | 51 (96.2) | 105 (99.1) | 0.216 |
| Occluded vessel diameter (mm), median (IQR) | 2.4 (2.2–3.1) | 2.5 (2.1–3.7) | 2.4 (2.2–2.9) | 0.555 |
| Catheter to vessel match rate, n (%) | 68 (42.8) | 13 (24.5) | 55 (51.9) | 0.001 |
| Clot contact rate, n (%) | 109 (68.6) | 17 (32.1) | 92 (86.8) | <0.0001 |
| Any ICH, n (%) | 84 (52.8) | 28 (52.8) | 56 (52.8) | 1 |
| Symptomatic ICH, n (%) | 11 (6.9) | 6 (11.3) | 5 (4.7) | 0.122 |
| Mortality at 90 days | ||||
| All cause, n (%) | 20 (12.9) | 5 (9.4) | 15 (14.7) | 0.353 |
| Stroke related, n (%) | 10 (6.5) | 4 (7.6) | 6 (5.9) | 0.689 |
ASPECTS, Alberta Stroke Program Early CT Score; CAC, conventional aspiration catheter; DWI, diffusion-weighted imaging; FPE, 1st-pass effect; ICA, internal carotid artery; ICH, intracranial hemorrhage; IQR, interquartile range; IV-tPA, intravenous tissue-type plasminogen activator; LAC, large-bore aspiration catheter; M1, M1 segment middle cerebral artery; mTICI, modified Thrombolysis in Cerebral Infarction; NIHSS, National Institutes of Health Stroke Scale
The sub-analyses of M1 occlusions in the LAC group are summarized in Table 2.
| No FPE | FPE | Univariate regression analysis | Multiple regression analysis | |||
|---|---|---|---|---|---|---|
| OR (95% CI) | P-value | OR (95% CI) | P-value | |||
| No. of patients | 30 | 45 | ||||
| Age (years), median (IQR) | 80 (74.75–85) | 82 (74.5–86.5) | 0.317 | |||
| Female, n (%) | 17 (56.7) | 22 (48.9) | 1.4 (0.5–3.5) | 0.509 | ||
| Cardiogenic embolism, n (%) | 22 (73.3) | 39 (86.7) | 0.4 (0.1–1.4) | 0.147 | ||
| Pre-stroke antithrombotic medication, n (%) | 9 (30.0) | 17 (37.8) | 0.7 (0.3–1.9) | 0.488 | ||
| IV-tPA, n (%) | 0 | 0 | — | — | ||
| 1st-line contact aspiration, n (%) | 18 (60.0) | 34 (75.6) | 0.5 (0.2–1.3) | 0.152 | ||
| Occluded vessel diameter (mm), median (IQR) | 2.25 (2.1–2.6) | 2.3 (2.2–2.5) | 0.602 | |||
| Clot contact rate, n (%) | 21 (70.0) | 44 (97.8) | 18.9 (2.2–158.7) | 0.0005 | 18.0 (1.9–172.9) | 0.013 |
| Catheter-to-vessel match rate, n (%) | 11 (36.7) | 39 (86.7) | 11.2 (3.6–35.0) | <0.001 | 10.9 (3.3–36.7) | 0.0001 |
| Siphon tortuosity, n (%) | 17 (56.7) | 23 (51.1) | 0.8 (0.3–2.0) | 0.637 | ||
Siphon tortuosity was defined as Types U and S according to the Zhong classification.5) CI, confidence interval; FPE, 1st-pass effect; IQR, interquartile range; IV-tPA, intravenous tissue-type plasminogen activator; M1, M1 segment middle cerebral artery; OR, odds ratio
In the univariate logistic regression analysis, CVM (odds ratio [OR], 11.2; 95% confidence interval [CI], 3.6–35.0; P <0.001) and clot contact (OR, 18.9; 95% CI, 2.2–158.7; P = 0.0005) were significantly more frequent in cases showing FPE success. FPE success was not significantly associated with patient age, sex, presence of cardiogenic embolism, pre-stroke antithrombotic medication, prior use of IV-tPA, 1st-line CA, occluded vessel diameter, or siphon tortuosity.
Multivariate logistic regression analysis confirmed CVM (OR, 10.9; 95% CI, 3.3–36.7; P <0.0001) and clot contact (OR, 18.0; 95% CI, 1.9–172.9; P = 0.013) as independent positive predictors of FPE success.
Successful reperfusion ratesSuccessful reperfusion, defined as a final mTICI score of 2b–3, was achieved in nearly all cases in the LAC group (99.1%). Furthermore, the LAC group demonstrated a significantly higher FPE rate than the CAC group (52.8% vs. 34.0%; P = 0.025).
This study showed that while LACs and CACs resulted in comparable treatment outcomes for ICA occlusions, LACs significantly improved the FPE rate for M1 occlusions, and that this improvement was associated with increased CVM and clot contact rates.
A comparison of MT outcomes across major previous studies is summarized in Table 3. The 2016 Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials (HERMES) collaboration was the first to comprehensively demonstrate the efficacy of thrombectomy for acute ischemic stroke, reporting a final mTICI ≥2b rate of 71.0% (402 of 570 patients).1) Subsequent advances in instrumentation and procedural technique have shifted the focus toward more stringent reperfusion goals, particularly achieving mTICI ≥2c in a single pass. Early studies that confirmed FPE as a strong predictor of favorable clinical outcomes include those by Zaidat et al., who reported an FPE rate of 25.1%,2) and Ducroux et al., whose sub-analysis of the Contact Aspiration vs Stent Retriever for Successful Revascularization (ASTER) trial showed an FPE rate of 28.9%.6) These treatment outcomes were comparable to those in the CAC group; however, in most studies conducted by 2019, the FPE rate rarely exceeded 40%.2,6–8) In line with these findings, the FPE rate in our CAC group was 34.0%, whereas it exceeded 50% in the LAC group; this represented a statistically significant improvement in reperfusion efficacy.
| Study | No. of patients | FPE mTICI 2c–3 (%) | Final mTICI 2b–3 (%) | Occlusion site | ||
|---|---|---|---|---|---|---|
| ICA (%) | M1 (%) | M2 (%) | ||||
| Goyal et al. (2016)1) | 634 | – | 71.0 | 21.0 | 69.0 | 8.0 |
| Zaidat et al. (2018)20) | 227 | 40.1 | 92.5 | 15.4 | 55.5 | 25.1 |
| Zaidat et al. (2018)2) | 354 | 25.1 | 72.0 | 23.2 | 55.4 | 11.0 |
| García-Tornel et al. (2019)7) | 542 | 24.9 | 84.5 | 32.7 | 49.8 | 18.1 |
| Ducroux et al. (2020)6) | 381 | 28.9 | 85.6 | 15.7 | 58.3 | 22.6 |
| Lapergue et al. (2021)8) | 405 | 37.3 | 87.9 | 17.4 | 64.1 | 16.1 |
| Bolognini et al. (2021)21) | 144 | 23.6 | 77.8 | 9.0 | 56.3 | 11.8 |
| Remollo et al. (2023)4) | 324 | 40.1 | 91.7 | — | 100 | — |
| Present study overall | 159 | 46.5 | 98.1 | 33.3 | 66.7 | — |
| CAC | 53 | 34.0 | 96.2 | 41.5 | 58.5 | — |
| LAC | 106 | 52.8 | 99.1 | 29.3 | 70.8 | — |
CAC, conventional aspiration catheter; FPE, 1st-pass effect; ICA, internal carotid artery; LAC, large-bore aspiration catheter; M1, M1 segment middle cerebral artery; M2, M2 segment middle cerebral artery; mTICI, modified Thrombolysis in Cerebral Infarction
CACs generally have IDs of 0.060–0.068 inch with ODs equivalent to 6 Fr. In comparison, LACs feature enlarged IDs (>0.070 inch) while maintaining similar ODs. As suction force is proportional to the product of pressure and cross-sectional area, it increases with the square of the catheter’s ID.9) Larger IDs enhance suction efficiency, resulting in higher recanalization rates and shorter procedural durations.10–13) Our findings, which show significantly greater FPE success in the LAC group (52.8%) than in the CAC group (34.0%), support the superior clinical outcomes attributed to larger IDs. However, the slightly increased ODs of LACs may also contribute to these improved outcomes.
Suction efficacy also depends on the surface area of the contact between the catheter tip and the thrombus. Optimal contact occurs when the catheter is aligned perpendicular to the vessel axis. When a substantial mismatch exists between the vessel diameter and catheter OD—as with CACs—axial misalignment becomes more likely. Conversely, a closer match, such as in LACs, promotes perpendicular alignment and improves thrombus engagement (Fig. 2). Kyselyova et al. demonstrated that CA success significantly improves when the catheter-to-vessel ratio (CVR) exceeds 85%.14) This may explain the superior performance of LACs observed in our study. Notably, we found no significant difference in the FPE rate between CACs and LACs in ICA occlusions. However, for M1 occlusions, the LAC group exhibited a significantly higher FPE rate. Anatomically, the ICA has a mean diameter of 4.74 ± 0.64 mm at the cervical segment and 3.40 ± 0.64 mm at the communicating segment, whereas the M1 segment averages 2.55 ± 0.42 mm.15) In our study, the ODs of CACs ranged from 1.8 to 2.0 mm, and those of LACs ranged from 2.08 to 2.16 mm. Due to the relatively large diameter of the ICA, both catheter types often failed to achieve a CVR ≥85%. In contrast, in the narrower M1 segment, LACs were more likely to achieve CVR ≥85%, enhancing CVM and thus improving FPE.
The higher FPE rate for M1 occlusions in the LAC group was significantly influenced by both improved CVM and a higher success rate in navigating to the occlusion site. While LACs were initially designed for increased suction area, newer models have enhanced trackability, improved torque response, and maintained tip flexibility. These characteristics facilitate catheter navigation even through tortuous anatomy, such as the ICA siphon. Koge et al.16) demonstrated that siphon tortuosity is an independent predictor of lower FPE rates, as per the Zhong classification,5) which designates Types U and S morphologies as tortuous and Types C and V as non-tortuous.
In our study, the clot contact rate in the CAC group was 32.1%, whereas the LAC group achieved a significantly higher rate of 86.8%. Notably, among M1 occlusion cases traversing the siphon, tortuosity (as per the Zhong classification) did not significantly affect FPE in the LAC group, highlighting the improved navigability of newer devices. The enhanced trackability of LACs has also been supported by techniques such as the SNAKE method,17) with similar approaches being reportedly feasible across multiple LAC models.18) Direct thrombus contact is well known to improve outcomes in CA and appears equally crucial for combined techniques.19) In our analysis, the FPE rates did not significantly differ between cases using CA as 1st-line therapy and those employing combined methods, reinforcing the fact that successful catheter navigation to the occlusion site is essential regardless of the thrombectomy approach.
However, there were several limitations in our study. This was a single-center, retrospective analysis without direct comparisons of LACs and CACs under identical procedural conditions. Additionally, our device selection was limited to certain commercial ACs, and the decision to switch from CA to the combined technique was left to the operator’s discretion; thus, our findings may not be generalizable across all currently available LACs.
Our results indicate that there are 2 critical factors for achieving FPE: selecting a catheter that achieves CVM appropriate to the occluded vessel diameter and successfully guiding it to the occlusion site. While vessel diameter varies with anatomic location, it is also influenced by individual factors such as age, sex, and race. Therefore, outcomes may be optimized by tailoring thrombectomy devices and strategies to each patient’s vascular anatomy rather than relying solely on predefined vessel segment classifications (e.g., ICA, M1, M2).
Daisuke Watanabe received lecture fees from Kaneka Medix. The remaining authors declare that they have no conflicts of interest.
