Mechanical Thrombectomy for Tandem Vertebrobasilar Stroke: Characteristics and Treatment Outcome

Endovascular Treatment for Acute Posterior Circulation Tandem Lesions: Insights From the BASILAR and PERSIST Registries

BACKGROUND AND PURPOSE

Limited evidence exists on the effectiveness of endovascular treatment (EVT) for acute posterior circulation tandem lesion (PCTL). This study aimed to explore the role of extracranial vertebral artery (VA) stenting in patients with PCTL stroke undergoing EVT.

METHODS

Individual patient data were pooled from the BASILAR (EVT for Acute Basilar Artery Occlusion Study) and PERSIST (Posterior Circulation Ischemic Stroke) registries. Patients with PCTLs who underwent EVT were included in the present cohort and divided into the stenting and nonstenting groups based on the placement of extracranial VA stents. The primary efficacy outcome was the modified Rankin Scale (mRS) scores at 90 days and 1 year. Safety outcomes included 24-hour symptomatic intracranial hemorrhage (sICH) and all-cause mortality at 90 days and 1 year post-surgery.

RESULTS

A combined dataset of 1,320 patients with posterior circulation artery occlusion, including 263 (19.9%) with tandem lesions, of whom 217 (median age, 65 years; 82.9% male) met the inclusion criteria for the analysis. The stenting group had 84 (38.7%) patients, while the non-stenting group had 133 (61.3%). After adjustment for the potential confounders, extracranial VA stenting was associated with favorable shifts in mRS scores at both 90 days (adjusted common odds ratio [OR], 2.30; 95% confidence interval [CI], 1.23-4.28; P<0.01) and 1 year (adjusted OR [aOR], 2.04; 95% CI [1.05-3.97]; P=0.04), along with lower rate of mortality at both 90 days (aOR, 0.45; 95% CI [0.21-0.93]; P=0.01) and 1 year (aOR, 0.36; 95% CI [0.16-0.79]; P=0.01), with no significant difference in sICH incidence (aOR, 0.35; 95% CI [0.06-1.98]; P=0.24).

CONCLUSION

Extracranial VA stenting during EVT may improve functional outcomes and reduce mortality in patients with PCTL strokes.

A Case of Acute Atherosclerotic Basilar Artery Occlusion Treated by Angioplasty with a Stent Retriever and Combined Antithrombotic Therapy

Objective

The optimal treatment strategy for large-vessel occlusion (LVO) related to intracranial atherosclerotic disease (ICAD), particularly for tandem lesions that complicate access and device delivery, remains unclear. We report a case in which angioplasty with a stent retriever (SR) and combined antithrombotic therapy was effective in treating re-occlusion associated with dissection of the residual stenosis after thrombectomy for acute atherosclerotic occlusion of the basilar artery (BA) with the left vertebral artery (VA) stenosis.

Case Presentation

An 80-year-old woman was brought to our hospital with progressively worsening consciousness and tetra-paresis. MRA revealed occlusion of the middle to proximal portion of the BA. The patient underwent percutaneous transluminal angioplasty using a balloon catheter for severe stenosis at the origin of the left VA, followed by mechanical thrombectomy for the BA occlusion. While initial recanalization was achieved, residual stenosis in the proximal portion of the BA led to re-occlusion. An attempt at angioplasty with a balloon catheter failed to reach the stenotic segment due to stenosis and tortuosity of the left VA. Consequently, the SR was redeployed into the BA, and a loading dose of antiplatelet agents and intravenous anticoagulant were administered during prolonged deployment. Following the confirmation of BA patency, the SR was re-sheathed and removed. The patient achieved remarkable improvement in consciousness and tetra-paresis without postoperative re-occlusion of the BA.

Conclusion

Angioplasty with a SR and combined antithrombotic therapy may be a useful treatment option for ICAD-related LVO, particularly in cases such as tandem lesions that hinder access and make distal balloon catheter navigation challenging.

Thrombectomy in ischemic stroke patients with tandem occlusion in the posterior versus anterior circulation

BACKGROUND

Mechanical thrombectomy (MT) was found to be beneficial in acute ischemic stroke patients with anterior tandem occlusion (a-TO). Instead, little is known about the effectiveness of MT in stroke patients with posterior tandem occlusion (p-TO). We aimed to compare MT within 24 h from last known well time in ischemic stroke patients with p-TO versus a-TO.

METHODS

We conducted a cohort study on prospectively collected data of patients registered in the Italian Registry of Endovascular Treatment in Acute Stroke (IRETAS) who were treated with MT within 24 h from last known well time for acute ischemic stroke with p-TO (n = 275) or a-TO (n = 1853).

RESULTS

After adjustment for unbalanced pre-procedure variables (year 2015-2021, age, sex, NIHSS score, ASPECTS, and time strata for puncture groin) and pre-stroke mRS score as pre-defined predictor, p-TO was significantly associated with lower probability of mRS score 0-2 (OR 0.415, 95% CI 0.268-0.644) and with higher risk of death (OR 2.813, 95% CI 2.080-3.805) at 3 months. After adjustment for unbalanced procedural and post-procedure variables (IVT, general anesthesia, TICI 3, and 24-h HT) and pre-stroke mRS score as pre-defined predictor, association between p-TO and lower probability of mRS score 0-2 (OR 0.444, 95% CI 0.304-0.649) and association between p-TO and with higher risk of death (OR 2.971, 95% CI 1.993-4.429) remained significant.

CONCLUSIONS

MT within 24 h from last known well time in ischemic stroke patients with p-TO versus a-TO was associated with worse outcomes at 3 months.

Endovascular revascularization of vertebrobasilar tandem occlusions in comparison to isolated basilar artery occlusions: A multi-center experience

BACKGROUND

Acute basilar artery occlusion (BAO) is a severe disease that is associated with an 85% mortality rate if untreated. Several studies have analyzed the use of mechanical thrombectomy (MT) in the different scenarios of BAO. However, the results remain conflicting and the role of MT as standard of care for vertebrobasilar tandem occlusions (VBTO) has not been confirmed. Our goal was to assess technical feasibility, safety, and functional outcome of endovascular treatment of VBTO in comparison to isolated BAO (IBAO).

METHODS

We retrospectively reviewed all prospectively collected patients with acute BAO from six tertiary centers between September 2016 and November 2021. Patients were subsequently divided into two groups: VBTO and IBAO. Baseline data, procedural details, and outcomes were compared between groups.

RESULTS

A total of 190 patients were included, 55 presenting with a VBTO and 135 with IBAO. Successful recanalization was equally common in both groups (89.1% and 86.0%). Rates of favorable functional outcome (modified Rankin Scale: 0-2) were higher in patients with VBTO compared to IBAO (36.4% vs. 25.2%, p = 0.048) and mortality was lower (29.1% vs. 33.3%). However, these associations faded after adjustment for confounders (adjusted odds ratio [aOR] 0.86, 95% CI 0.35-2.05; aOR 0.93, 95% CI 0.35-2.45). Rates of symptomatic intracranial hemorrhage did not differ between the groups (VBTO: 7.3% vs. IBAO: 4.2%; p = 0.496).

CONCLUSION

Endovascular treatment of VBTO is technically feasible and safe with similar rates of successful recanalization, favorable functional outcome, and mortality to those in patients with IBAO.

Effects and safety of endovascular recanalization for non-acute symptomatic intracranial vertebral artery occlusion with different risks

There is no consensus on the optimal treatment for non-acute symptomatic intracranial vertebral artery occlusion, and endovascular recanalization is a challenging procedure. We report our clinical experience of endovascular recanalization in patients with non-acute symptomatic intracranial vertebral artery occlusion to assess the feasibility and safety of endovascular recanalization and determine the candidate patients for this procedure. Ninety-two patients with non-acute symptomatic intracranial vertebral artery occlusion who underwent endovascular recanalization from January 2019 to December 2021 were retrospectively analyzed. we grouped all patients according to imaging examination findings, occlusion length, duration, nature, calcification, and angulation to evaluate the risk of endovascular recanalization. The overall success rate of endovascular recanalization was 83.7% (77/92), and the perioperative complication rate was 10.9% (10/92). Among the 3 classification groups, the recanalization success rate gradually decreased from the low-risk group to the high-risk group (low-risk: 100%, medium-risk: 93.3%, high-risk group: 27.8%, P = .047), while the overall perioperative complication rate showed the opposite trend (0%, 10.0%, 38.9%, respectively, P = .001); the proportion of patients with 90-day modified Rankin Scale scores of 0-2 decreased successively (100%, 83.3%, and 22.2%, respectively, P < .026); 77 patients with successful recanalization were followed; the rate of restenosis/reocclusion increased sequentially (0%, 17.9%, and 80%, respectively, P = .000). Patients in the low- and medium-risk groups showed a good clinical course after endovascular recanalization. Among 88 patients (four patients lost to follow-up), with a median clinical follow-up of 13 months (interquartile range ¼, 7-16), the rate of stroke or death after 30 days was 17.4% (16/92). Endovascular recanalization is safe and feasible for low- and medium-risk patients with non-acute symptomatic intracranial vertebral artery occlusion; it is also an alternative to conservative therapy for the patients.

Effect of endovascular treatment on patients with basilar artery occlusion presenting with different pathologic mechanisms: a systematic review and meta-analysis

OBJECTIVE

This study aimed to summarize the clinical outcomes of endovascular treatment in patients with basilar artery occlusion (BAO) with different pathologic mechanisms.

METHODS

Two independent reviewers searched PubMed/MEDLINE, Embase and Cochrane Library database up to December 2022, patients with different BAO pathological mechanisms (BAO with in situ atherosclerosis vs. embolism alone without vertebral artery steno-occlusion vs. embolism from tandem vertebral artery steno-occlusion) were collected and analyzed. We calculated the odds ratios (ORs) and 95% confidence intervals (CIs) to assess the associations between clinical outcomes and BAO pathological mechanisms.

RESULTS

A total of 1163 participants from 12 studies were identified. Compared with embolism alone, patients with in situ atherosclerotic BAO had a lower favorable outcome rate (modified Rankin score [mRS] 0-2: 34.5% vs. 41.2%; OR 0.83, 95% CI 0.70-0.98; P = 0.03) and moderate outcome rate (mRS 0-3: 45.8% vs. 55.4%; OR 0.65, 95% CI 0.47-0.90; P = 0.01) at 3 months and a higher risk of mortality (29.9% vs. 27.2%; OR 1.31, 95% CI 0.96-1.79, P = 0.09; adjusted OR 1.46, 95% CI 1.08-1.96). Tandem BAO had a comparable mortality risk to that of in situ atherosclerotic BAO (OR 1.37, 95% CI 0.84-2.22; P = 0.48) or embolism alone (OR 1.44, 95% CI 0.65-3.21; P = 0.43), and there were no significant differences in favorable or moderate outcomes between tandem BAO and each of the other two BAO mechanisms.

CONCLUSION

Among BAO patients with endovascular treatment, embolism mechanism had better clinical outcomes than in situ atherosclerosis, and atherosclerotic mechanism was associated with a higher mortality at 3 months. RCTs are needed to further confirm clinical outcomes of BAO by different mechanisms.

Basilar artery occlusion: A review of clinicoradiologic features, treatment selection, and endovascular techniques

Basilar artery occlusion (BAO) is an infrequent but often fatal subtype of stroke. Predicting outcomes and selecting patients for endovascular therapy (EVT) remains challenging. Advances in neuroimaging and the development of prognostic scoring systems have augmented clinical decision-making over time. Recent randomized trials, BEST (Basilar Artery Occlusion Endovascular Intervention vs. Standard Medical Treatment), BASICS (Basilar Artery International Cooperation Study), BAOCHE (Basilar Artery Occlusion CHinese Endovascular Trial) and ATTENTION (Endovascular Treatment for Acute Basilar Artery Occlusion), compared EVT and medical management for patients with BAO. These trials yielded mixed results. The former two suggested unclear benefit while the latter two supported a benefit of EVT. While all had limitations, most providers agree caution should be exercised when excluding patients from EVT who may stand to benefit. Further studies are therefore needed to determine the effectiveness, safety, selection criteria, and optimal technical approach for EVT among patients with BAO. Hyperacute-phase advanced imaging can offer several benefits to aid decision making. It is reasonable to exclude patients with low National Institutes of Health Stroke Scale (NIHSS), large imaging-proven cores, and evidence of perforator occlusion by branch atheromatous disease. Herein, we review the clinical presentation, imaging work-up, treatments, and clinical outcomes for BAO, while highlighting knowledge gaps in treatment selection and technique.

Management of posterior circulation tandem occlusions in acute ischemic stroke: Recanalize the dominant vertebral artery with priority

PURPOSE

To illustrate the characteristics of acute ostial vertebral artery (VA) and basilar artery (BA) tandem occlusions. The endovascular treatment strategy for ostial VA-BA tandem occlusion was reported.

MATERIALS AND METHODS

We conducted a retrospective analysis of patients with ostial VA-BA tandem occlusion who underwent endovascular treatment in our center between November 2018 and February 2022. We preferred to recanalize the dominant vertebral artery with priority. The imaging characteristics, treatment strategy, clinical outcomes, and complications were analyzed.

RESULTS

In total, 9 patients with ostial VA-BA tandem occlusion were enrolled in this study. All the VA-BA tandem occlusion was caused by acute occlusion of the dominant VA. Endovascular revascularization was performed through the occluded dominant VA in 8 patients and was performed through contralateral non-dominant VA in 1 patient. Successful recanalization (mTICI 2b/3 grade) was achieved in all 9 patients, and 5 patients (55.5%) achieved functional independence with a mRS score of 0-2 at 90 days.

CONCLUSIONS

In this case series, the occurrence of ostial VA-BA tandem occlusions was mainly caused by acute occlusion of the dominant VA. Endovascular revascularization of ostial VA-BA tandem occlusions through occluded dominant VA was feasible and recommended.

Comprehensive classifications for the endovascular recanalization of vertebral artery stump syndrome

Background

and purpose: To share our single-center vertebral artery stump syndrome (VASS) treatment experience and assess the role of comprehensive classification based on anatomic development, proximal conditions, and distal conditions (PAD).

Materials and methods

Data were retrospectively collected from patients who underwent endovascular thrombectomy (EVT) at the Stroke Center of the First Hospital of Jilin University between January 2016 and December 2021. Among patients with acute ischemic stroke in the posterior circulation, those with acute occlusion of the intracranial arteries and occlusion at the origin of the vertebral artery confirmed by digital subtraction angiography were selected. The clinical data were summarized and analyzed.

Results

Fifteen patients with VASS were enrolled in the study. The overall success rate of surgical recanalization was 80%. The successful proximal recanalization rate was 70.6%, and the recanalization rates for P1, P2, P3, and P4 were 100%, 71.4%, 50%, and 66.67%, respectively. The mean operation times for the A1 and A2 types were 124 and 120 ​min, respectively. The successful distal recanalization rate was 91.7%, and the recanalization rates for types D1, D2, D3, and D4 were 100%, 83.3%, 100%, and 100%, respectively. Five patients experienced perioperative complications (incidence rate: 33.3%). Distal embolism occurred in three patients (incidence rate: 20%). No dissection or subarachnoid hemorrhage occurred in any patient.

Conclusion

EVT is a technically feasible treatment for VASS, and comprehensive PAD classification can, to a certain extent, help initially estimate the difficulty of surgery and provide guidance for interventional procedures.

Acute reperfusion therapy via occluded vertebral artery using a guiding sheath for posterior circulation tandem occlusion: illustrative case

BACKGROUND

Vertebral artery (VA) size, anatomy, and occlusion status should be considered when selecting endovascular access for basilar artery mechanical thrombectomy. In a patient with concomitant basilar artery and VA occlusion and a patent but hypoplastic contralateral VA, the occluded VA should be selected. The authors report a technique that utilizes advancing a guiding sheath with attached dilator via an occluded VA.

OBSERVATIONS

A 65-year-old male presented with disturbed consciousness because of an acute infarction of the brainstem and cerebellum caused by a basilar artery occlusion. Cerebral angiography showed a hypoplastic right VA and occlusion of the left VA at the origin. A regular wire was easily advanced through the occlusion and a 4-Fr diagnostic catheter was advanced into the distal left VA. A 6-Fr guiding sheath with attached dilator was placed in the left VA beyond the occlusion by exchanging it over a long wire. After removing the basilar artery thrombus, balloon angioplasty was performed at the left VA origin. Complete revascularization of the posterior circulation was achieved.

LESSONS

A guiding sheath with dilator can advance across and dilate a VA occlusion at the origin to provide rapid access to the basilar artery.

Mechanical thrombectomy for vertebral and basilar artery occlusions: An institutional experience with 17 patients

Acute ischemic stroke of the posterior circulation as a result of vertebrobasilar artery occlusions is often associated with severe morbidity and mortality rates. Vertebrobasilar artery occlusion retrieval via mechanical thrombectomy (MT) is a novel treatment modality for occlusive strokes. Nevertheless, factors associated with positive outcomes have not yet been adequately investigated. Thus, the present study focused on factors associated with good prognosis following this type of treatment. The present study retrospectively analyzed a series of 17 patients with acute vertebral artery occlusions (VAOs) and basilar artery occlusions (BAOs) treated with MT. In all patients, information such as sex and age, time from admission to the onset of femoral artery access, the number of thrombi removed, the time of femoral artery access to recanalization, pre- and post-operative National Institutes of Health Stroke Scale (NIHSS) scores, pre- and post-operative thrombolysis in cerebral infarction, as well as modified Rankin scale scores were documented and analyzed. The analysis comprised of 11 patients with BAOs and 6 patients with VAOs. A recanalization rate of 70.6% was achieved with an overall good functional outcome of 58.8% at 90 days. Observationally, there was a notable improvement in outcomes when comparing the NIHSS prior to surgery with NIHSS at 1 week after the surgery. A lower NIHSS score prior to MT may be a good prognostic factor. An average time of ~5.5 h from patient admittance to recanalization with a 70.6% recanalization rate with an overall good functional outcome of 58.8% at 90 days suggested that, patients for whom the surgeries were performed within 5 h of admittance may still have hope for recanalization compared to an initial 1.5-h average time for recanalization.

Endovascular Treatment for Posterior Circulation Stroke: Ways to Maximize Therapeutic Efficacy

The efficacy of endovascular treatment (EVT) in patients with posterior circulation stroke has not been proven. Two recent randomized controlled trials failed to show improved functional outcomes after EVT for posterior circulation stroke (PC-EVT). However, promising results for two additional randomized controlled trials have also been presented at a recent conference. Studies have shown that patients undergoing PC-EVT had a higher rate of futile recanalization than those undergoing EVT for anterior circulation stroke. These findings call for further identification of prognostic factors beyond recanalization. The significance of baseline clinical severity, infarct volume, collaterals, time metrics, core-penumbra mismatch, and methods to accurately measure these parameters are discussed. Furthermore, their interplay on EVT outcomes and the potential to individualize patient selection for PC-EVT are reviewed. We also discuss technical considerations for improving the treatment efficacy of PC-EVT.

Non-invasive Detection of Diffuse Intracranial Vertebrobasilar Artery Stenosis: A Prospective Comparison with Digital Subtraction Angiography

The aim of this study was to prospectively evaluate diffuse intracranial vertebrobasilar artery stenosis by ultrasonic examination with digital subtraction angiography as the reference. Five hundred forty-one vertebrobasilar arteries with a normal lumen or intracranial stenosis were enrolled. Peak systolic velocity, mean flow velocity and end-diastolic velocity (EDV) at the intracranial vertebrobasilar arteries and extracranial vertebral arteries (VAs) were measured. The resistance index (RI) at extracranial VAs and the difference between the RI of extracranial VAs and the RI of the extracranial internal carotid artery (RI_ica) were calculated. Compared with normal arteries, all stenotic arteries were divided into the high-velocity group (focal stenosis, multiple-segment stenosis and multiple-artery stenosis) and low-velocity group (critical stenosis and long stenosis). The consistency between ultrasonic examination and digital subtraction angiography for evaluation of vertebrobasilar arteries with multiple-segment stenosis and multiple-artery stenosis was not favorable when applying the widely used Stroke Outcomes and Neuroimaging of Intracranial Atherosclerosis criteria (κ = 0.442 and 0.438, respectively). The optimal low-velocity criteria for identifying intracranial vertebrobasilar arteries with critical stenosis and long stenosis were determined by receiver operating characteristic curve analysis and were as follows: EDV ≤15 cm/s and RI ≥0.68 at the extracranial VA and RIica ≥0.10.

Outcomes of Endovascular Therapy in Acute Basilar Artery Occlusion With Severe Symptoms

IMPORTANCE

Endovascular therapy (EVT) has been reported to be safe and effective in improving clinical outcomes among patients with acute basilar artery occlusion (ABAO). The benefits associated with EVT remain uncertain for patients with ABAO with severe symptoms (ie, National Institutes of Health Stroke Scale [NIHSS] score ≥ 21).

OBJECTIVES

To assess the outcomes associated with EVT and identify factors associated with outcomes among patients with ABAO and severe symptoms.

DESIGN, SETTING, AND PARTICIPANTS

This prospective, nationwide cohort study was conducted using data from January 2014 to May 2019 in China from the Endovascular Treatment for Acute Basilar Artery Occlusion Study Registry (BASILAR). Included patients had ABAO and underwent EVT or standard medical treatment (SMT) alone in routine clinical practice. Patients were dichotomized into severe symptoms (ie, NIHSS score ≥ 21) and minor to moderate symptoms (NIHSS score < 21) groups. Patients were followed up for 90 days. Data were analyzed from December 2020 through June 2021.

EXPOSURES

EVT with SMT vs SMT alone.

MAIN OUTCOMES AND MEASURES

The primary outcome was improvement in modified Rankin Scale (mRS) score at 90 days, defined as a decrease by 1 grade in mRS score. Secondary outcomes included favorable functional outcome (ie, mRS score, 0-3) and mortality.

RESULTS

Among 542 patients with ABAO and severe symptoms (median [IQR] age, 65 [57-74] years; 147 [27.1%] women), 431 patients (79.5%) received EVT and 111 patients (20.5%) received SMT. Compared with SMT, EVT was associated with increased odds of improved mRS score (adjusted common odds ratio [OR], 3.44 [95% CI, 2.05-5.78]; P < .001), with increased odds of a favorable functional outcome (ie, mRS score, 0-3; adjusted OR, 4.52 [95% CI, 1.64-12.43]; P = .004) and decreased odds of mortality (adjusted OR, 0.27 [95% CI, 0.15-0.50]; P < .001). Among patients receiving EVT, baseline NIHSS score was associated with decreased odds of a favorable functional outcome (adjusted OR per 1-point increase in score, 0.90 [95% CI, 0.85-0.95]; P < .001) and increased odds of mortality (adjusted OR per 1-point increase in score, 1.13 [95% CI, 1.07-1.19]; P < .001), while posterior circulation Acute Stroke Prognosis Early Computed Tomography Score (pc-ASPECTS) was associated with increased odds of a favorable functional outcome (adjusted OR per 1-point increase in score, 1.71 [95% CI, 1.41-2.07]; P < .001) and decreased odds of mortality (adjusted OR per 1-point increase in score, 0.74 [95% CI, 0.64-0.85]; P < .001). Different occlusion sites, compared with distal basilar artery, were associated with decreased odds of favorable functional outcome (eg, middle basilar artery: adjusted OR vs distal basilar artery, 0.36 [95% CI, 0.17-0.80]; P = .01).

CONCLUSIONS AND RELEVANCE

This study found that EVT was associated with increased odds of functional favorable outcomes among patients with ABAO and severe symptoms. Baseline NIHSS score, pc-ASPECTS, and occlusion site were independent factors associated with clinical outcomes.

Revascularization of vertebrobasilar tandem occlusions: a meta-analysis

PURPOSE

To investigate the difference in mechanical thrombectomy (MT) outcomes between vertebrobasilar tandem occlusion (VBTO) and isolated basilar artery (BA) occlusion (non-VBTO) and the difference in rates of successful recanalization between the clean-road and dirty-road pathways, in VBTO.

METHODS

We conducted a meta-analysis after searching PubMed, EMBASE, and Google Scholar databases as of April 2021. We only included adult patients who underwent MT to treat acute ischemic stroke (AIS) due to VBTO, and the following outcomes should be reported: successful recanalization, functional outcome at 90 days, and symptomatic intracerebral hemorrhage (sICH). The main effect size measures were odds ratio and risk difference, and the software used was RevMan 5.4.

RESULTS

The analysis included 81 VBTO and 324 non-VBTO patients (seven studies). We found no significant difference regarding 3 m functional independence [4 studies: OR = 1.71 (95% CI, 0.54, 5.43), I² = 75%], 3 m mortality [4 studies: OR = 1.62 (95% CI, 0.62, 4.25), I² = 66%], sICH [4 studies: OR = 1.71 (95% CI, 0.67, 4.39), I² = 0%], and successful recanalization [3 studies: OR = 0.81 (95% CI, 0.12, 5.57), I² = 80%]. A subgroup analysis of 118 VBTO patients (five studies) showed no significant difference in successful recanalization between clean-road and dirty-road pathways [RD = 0.07 (95% CI, - 0.09, 0.24), I² = 40%].

CONCLUSION

The results of this meta-analysis support the use of MT for AIS patients with VBTO. In VBTO patients, none of the clean-road or dirty-road pathways proved to be superior to the other.