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Mechanical Thrombectomy Using Solitaire in Acute Ischemic Stroke Patients with Vertebrobasilar Occlusion: A Prospective Observational Study
Original Article
Mechanical Thrombectomy Using Solitaire in Acute Ischemic Stroke Patients with Vertebrobasilar Occlusion: A Prospective Observational Study Hong-Fei Sang, Cong-Guo Yin, Wen-Qing Xia, Huan Huang, Ke-Qin Liu, Tian-Wen Chen, Xiao-Li Si, Lin Jiang
BACKGROUND: The safety and effectiveness of endovascular mechanical thrombectomy in patients with acute vertebrobasilar occlusion (VBO) are debatable and undergoing evaluation. We report the clinical outcome and prognostic factors in a prospective cohort of acute ischemic stroke patients with VBO.
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METHODS: In total, 48 consecutive patients with acute VBO underwent mechanical thrombectomy using Solitaire. We analyzed clinical and imaging data and searched for predictors of good clinical outcome (modified Rankin scale score: 0e3).
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RESULTS: The median prethrombectomy National Institutes of Health Stroke Scale score was 22.0. The median duration from symptom onset to recanalization was 493.5 minutes. A total of 35.4% of the patients received rescue therapy. Recanalization (modified Thrombolysis In Cerebral Infarction: 2be3) was successful in all patients. Clinically relevant intracranial hemorrhage was observed in 2 patients. After 90 days, good outcomes were obtained in 27 patients. The baseline National Institutes of Health Stroke Scale score, posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS), anesthesia type, and posterior communicating artery (PComA) patency were significantly associated with outcomes at 90 days in univariate analysis. Multivariate logistic regression indicated
that high pc-ASPECTS at admission and PComA patency were independent predictors of good outcome at 90 days. CONCLUSIONS: Up to 60.4% of the patients reached good outcomes after endovascular treatment and 35.4% of the patients received rescue therapy, suggesting that mechanical thrombectomy using Solitaire in patients with stroke with VBO is safe and effective and that rescue therapy is readily required and employed. High baseline pc-ASPECTS and PComA patency were associated with better outcomes after thrombectomy in these patients.
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Key words Acute ischemic stroke - Endovascular treatment - Mechanical thrombectomy - Posterior circulation - Vertebrobasilar occlusion -
Abbreviations and Acronyms AIS: Acute ischemic stroke BA: Basilar artery BASICS: Basilar Artery International Cooperation Study IAT: intra-arterial therapy ICH: intracerebral hemorrhage IQR: interquartile range mRS: Modified Rankin scale score MT: Mechanical thrombectomy mTICI: Modified thrombolysis in cerebral infarction score NIHSS: National Institutes of Health Stroke Scale
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INTRODUCTION cute ischemic stroke (AIS) caused by vertebrobasilar occlusion (VBO) accounts for approximately 20% of all cases of ischemic stroke; however, it is the most devastating type of stroke, having mortality and disability rates of up to 90% in the absence of recanalization.1 Conclusive evidence from several recent randomized controlled trials have suggested that stent retriever thrombectomy improves the outcome of patients with AIS with anterior circulation large-vessel occlusion.2-4 However, the safety and effectiveness are less clear in patients with stroke with acute VBO. To date, to the best of our knowledge, there are no data from randomized controlled trials comparing intravenous
A
pc-ASPECTS: Posterior circulation Acute Stroke Prognosis Early CT Score PComA: Posterior communicating artery SICH: symptomatic intracerebral hemorrhage TOAST: Trial of ORG 10172 in Acute Stroke Treatment VBO: Vertebrobasilar occlusion Department of Neurology, Hangzhou First People’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, P.R. China To whom correspondence should be addressed: Lin Jiang, M.D. [E-mail: [email protected]] Hong-Fei Sang and Cong-Guo Yin contributed equally to this article and are coefirst authors. Citation: World Neurosurg. (2019). https://doi.org/10.1016/j.wneu.2019.04.152 Journal homepage: www.journals.elsevier.com/world-neurosurgery Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2019 Elsevier Inc. All rights reserved.
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MT USING SOLITAIRE IN AIS WITH VBO
Table 1. Baseline, Procedural, and Outcome Parameters Patient Characteristics
Overall (n [ 48)
Good Outcome (n [ 29)
Poor Outcome (n [ 19)
P Value
Age, years, median (IQR)
70.5 (62.0e80.0)
67.0 (60.5e80.0)
79.0 (63.0e80.0)
0.237
Female, % (n) Baseline NIHSS score, median (IQR) pc-ASPECTS, median (IQR)
25.0 (12/48)
20.7 (6/29)
31.6 (6/19)
0.501
22.0 (12.5e26.0)
19.0 (9.0e23.0)
25.0 (22.0e27.0)
0.002*
9.0 (8.0e10.0)
9.0 (9.0e10.0)
9.0 (7.0e9.0)
0.005*
37.5 (18/48)
41.4 (12/29)
31.6 (6/19)
Occlusion site, % (n)
0.588
Distal BA Mid-BA
16.7 (8/48)
13.8 (4/29)
21.1 (4/19)
Proximal BA
35.4 (17/48)
30.1 (9/29)
42.1 (8/19)
VA
10.4 (5/48)
13.8 (4/29)
5.3 (1/19)
Atrial fibrillation, % (n)
43.8 (21/48)
34.5 (10/29)
57.9 (11/19)
0.110
Hypertension, % (n)
72.9 (35/48)
69.0 (20/29)
78.9 (15/19)
0.447
Diabetes, % (n)
16.7 (8/48)
13.8 (4/29)
21.1 (4/19)
0.695
IHD, % (n)
4.2 (2/48)
3.4 (1/29)
5.3 (1/19)
1.000
Previous stroke/TIA, % (n)
12.5 (6/48)
10.3 (3/29)
15.8 (3/19)
0.669
Hyperlipidemia, % (n)
20.8 (10/48)
13.8 (4/29)
31.6 (6/19)
0.164
TOAST, % (n)
0.256
Atherosclerosis
60.4 (29/48)
62.1 (18/29)
57.9 (11/19)
Cardioembolic
33.3 (16/48)
27.6 (8/29)
42.1 (8/19)
6.3 (3/48)
10.3 (3/29)
0.0 (0/19)
Conscious sedation, % (n)
85.4 (41/48)
93.1 (27/29)
73.7 (14/19)
0.097*
IV rt-PA, % (n)
20.8 (10/48)
20.7 (6/29)
21.1 (4/19)
1.000
Others Reperfusion therapy
Number of retrieval passes, median (IQR)
2.0 (1.0e3.0)
2.0 (1.0e3.0)
2.0 (1.0e3.0)
0.665
Procedure duration, minutes, median (IQR)
83.5 (60.0e128.5)
73.0 (58.0e103.5)
101.0 (67.0e144.0)
0.114
493.5 (383.6e850.0)
470.0 (376.5e852.0)
510.0 (380.0e867.0)
0.975
mTICI, score ¼ 3, % (n)
Onset to recanalization duration, minutes, median (IQR)
93.8 (45/48)
96.6 (28/29)
89.5 (17/19)
0.554
Vessel perforation, % (n)
4.2 (2/48)
6.9 (2/29)
0.0 (0/19)
0.512
PComA patency, % (n)
64.6 (31/48)
79.3 (23/29)
42.1 (8/19)
0.008*
Balloon angioplasty or stenting, % (n)
35.4 (17/48)
27.6 (8/29)
47.4 (9/19)
0.161
Residual stenosis, % (n)
58.3 (28/48)
58.6 (17/29)
57.2 (11/19)
0.960
75.0 (0.0e90.0)
50.0 (0.0e90.0)
90.0 (0.0e90.0)
0.474
Tirofiban, % (n)
56.3 (27/48)
55.2 (16/29)
57.9 (11/19)
0.853
Any ICH, % (n)
16.7 (8/48)
17.2 (5/29)
15.8 (3/19)
1.000
SICH, PH-2 decline, % (n)
4.2 (2/48)
0.0 (0/29)
10.5 (2/19)
0.152
10.0 (2.3e23.0)
5.0 (2.0e11.0)
25.0 (18.0e27.0)
<0.001*
Residual stenosis rate, median (IQR)
24-hour NIHSS score, median (IQR)
The P value was calculated by the c test for categorial variables and ManneWhitney U test for continuous variables. IQR, interquartile range; NIHSS, National Institutes of Health Stroke Scale; pc-ASPECTS, posterior circulation Alberta Stroke Program Early CT Score; BA, basilar artery; VA, vertebral artery; IHD, ischemic heart disease; TIA, transient ischemic attack; TOAST, Trial of ORG 10172 in Acute Stroke Treatment; IV, intravenous; rt-PA, recombinant tissue plasminogen activator; mTICI, Modified Thrombolysis In Cerebral Infarction; PComA, posterior communicating artery; ICH, intracerebral hemorrhage; SICH, symptomatic intracerebral hemorrhage; PH, parenchymal hematoma. *P < 0.05. 2
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ORIGINAL ARTICLE HONG-FEI SANG ET AL.
MT USING SOLITAIRE IN AIS WITH VBO
Figure 1. Distribution of the modified Rankin scale (mRS) score for all patients at 90 days.
thrombolysis with intra-arterial therapy (IAT) in patients with AIS with VBO. In the past decade, case series and observational studies have described using IAT for patients with acute basilar artery (BA) occlusion. These studies have suggested that patients with acute posterior circulation stroke also benefit from IAT. However, data on IAT in Chinese patients with AIS and VBO are insufficient.5-8 Therefore, the objective of the present study was to evaluate the effectiveness and safety of modern mechanical thrombectomy (MT) using Solitaire (ev3, Irvine, California, USA) for acute VBO among Chinese patients with AIS and to identify prognostic factors that may influence the clinical outcome.
METHODS Study Design and Patients This prospective study enrolled 48 consecutive patients with AIS confirmed to have acute VBO at the Department of Neurology of Hangzhou First People’s Hospital between January 1, 2016, and July 15, 2018. Hangzhou First People’s Hospital is affiliated to Zhejiang University and is a comprehensive stroke center in eastern China. This study was reviewed and approved by the local institutional review board. Written informed consent was obtained from the patients or their legal representatives before participating. Patients who were aged 18 years and presented with stroke due to acute VBO within 24 hours that was confirmed by computed tomography angiography or magnetic resonance angiography posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS) score 6, baseline National Institutes of Health Stroke Scale (NIHSS) score 6 were eligible to participate. Wake-up stroke onset was calculated from the last normal time to the time of discovery, less than 24 hours. The exclusion criteria were as follows: 1) intracerebral hemorrhage when noncontrastenhanced computed tomography was performed at admission; 2) history of intracerebral hemorrhage, subarachnoid hemorrhage, arteriovenous malformation, or tumor; 3) pre-existing dependency with modified Rankin Scale (mRS) score of 3; 4) pc-ASPECTS
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score <6; and 5) renal failure as indicated by serum creatinine levels of >2.0 mg/dL (177 mmol/L). Clinical Assessment Clinical and radiologic data were prospectively collected. Demographic characteristics, cerebrovascular risk factors, pcASPECTS, and NIHSS score at admission were evaluated and documented by 2 neurologists. After clinical and neuroimaging evaluations, patients with acute VBO were considered eligible to undergo IAT based on the judgment of the interventional neurologists. Our protocol recommended IAT for patients with acute VBO up to 24 hours after symptom onset. Factors related to treatment outcomes were investigated. These factors were TOAST classification (Trial of ORG 10172 in Acute Stroke Treatment), anesthesia type, arterial occlusion site, collateral circulation, tirofiban usage, estimated stroke-onset duration, procedure duration, onset-to-recanalization duration, and reperfusion therapy status. A method for determining the symptom onset duration was the last known normal time. Collateral circulation is defined as the patency of posterior communicating artery (PComA). Endovascular Procedures Because Solitaire has the following advantages, e.g., it first entered the Chinese market; there are many sizes to choose from; the commonly used ones are 4 20 mm and 6 30 mm; it has no head end and the safety is greater; and its invalid area is short, this study used Solitaire as a first-line treatment. All patients underwent IAT using Solitaire combined with or without additional angioplasty for reperfusion either directly or after intravenous thrombolysis with recombinant tissue plasminogen activator. All interventions were performed by experienced neurointerventionalists on a biplane system in a neuroangiography suite with the patient under conscious sedation or general anesthesia. When MT using Solitaire failed to achieve successful reperfusion in patients (modified Thrombolysis In Cerebral Infarction Score [mTICI] score: 0e2a), the neurointerventionalists switched to
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MT USING SOLITAIRE IN AIS WITH VBO
Table 2. Details of Patients Who Were Treated by a Combined Method Patient Characteristics Age, years, median (IQR) Male, % (n) Baseline NIHSS score, median (IQR) pc-ASPECTS, median (IQR)
67.0 (60.5e78.0) 86.2 (25/29) 22.0 (11.5e27.0) 9.0 (8.0e10.0)
Occlusion site, % (n) Distal BA
13.8 (4/29)
Mid-BA
17.2 (5/29)
Proximal BA
51.7 (15/29)
VA
17.2 (5/29)
TOAST, % (n) Atherosclerosis Others
93.1 (27/29) 6.9 (2/29)
Reperfusion therapy IV rt-PA, % (n)
20.7 (6/29)
Number of retrieval passes, median (IQR)
2.0 (1.0e3.0)
Procedure duration, minutes, median (IQR)
101.0 (67.5e141.0)
Onset to recanalization duration, minutes, median (IQR)
569.0 (417.0e833.0)
Outcome Measures In accordance with the Basilar Artery International Cooperation Study (BASICS) registry, stroke severity was dichotomized as severe or mild-to-moderate.9 The primary outcome was a good 90day outcome defined as an mRS score of 0e3. The mRS score at 90 days was assessed by 2 independent trained neurologists who were unaware of treatment information during face-to-face interviews. Other outcomes included successful recanalization with an mTICI score of 2b or 3 and symptomatic intracerebral hemorrhage (SICH). SICH was defined as hemorrhage on the follow-up computed tomography/magnetic resonance imaging scan associated with an increase of the NIHSS score by 4. Statistical Analysis Statistical analyses were performed using IBM SPSS Statistics 21 (IBM Corp., Armonk, New York, USA). Baseline data of categorical variables were described using frequencies and proportions, whereas continuous variables were described using mean (standard deviation) or median (interquartile range [IQR]: 25%e75%). Patients with good outcomes were compared with those with poor outcomes. The c2 test or Fisher exact test was used for categorical variables, and the Student t test or ManneWhitney U test was used for continuous variables. Multivariate logistic regression analysis for predictors of good clinical outcome was performed for all variables significant at P < 0.1 in the univariate analysis. A P value of <0.05 was considered significant.
mTICI, score ¼ 3, % (n)
89.6 (26/29)
RESULTS
PComA patency, % (n)
68.9 (20/29)
Balloon angioplasty, % (n) Stenting, % (n)
20.7 (6/29) 37.9 (11/29)
Tirofiban, % (n)
93.1 (27/29)
Any ICH, % (n)
20.7 (6/29)
Baseline Characteristics There were 36 male and 12 female patients, with a mean age of 70.5 years. The median NIHSS score and pc-ASPECTS at admission are shown in Table 1. The occlusion sites confirmed by angiography also are presented in Table 1. In total, 29 patients (60.4%) reached a good clinical outcome at 90 days (Figure 1).
SICH, PH-2 decline, % (n)
6.9 (2/29)
24-hour NIHSS score, median (IQR) mRS score after 3months (0e3), % (n)
13.0 (2.0e22.0) 62.1% (18/29)
IQR, interquartile range; NIHSS, National Institutes of Health Stroke Scale; pc-ASPECTS, posterior circulation Alberta Stroke Program Early CT Score; BA, basilar artery; VA, vertebral artery; TOAST, Trial of ORG 10172 in Acute Stroke Treatment; IV, intravenous; rt-PA, recombinant tissue plasminogen activator; mTICI, Modified Thrombolysis In Cerebral Infarction; PComA, posterior communicating artery; ICH, intracerebral hemorrhage; SICH, symptomatic intracerebral hemorrhage; PH, parenchymal hematoma; mRS, modified Rankin scale.
either balloon or stent percutaneous transluminal angioplasty. mTICI scores were estimated from angiographic runs before and after the procedure. Angiographic images were assessed, and 2 trained neuroradiologists reached a consensus. Tirofiban, which is a fast-acting glycoprotein IIb/IIIa inhibitor that prevents platelet aggregation and improves cerebral perfusion, was intravenously administered in patients undergoing stent-assisted angioplasty at a first dose of 6.7 mg/kg and continued at a dosage of 0.08 mg/kg/ min for 24 hours.
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Periprocedural Characteristics Among the 48 patients, 41 (85.4%) were treated under conscious sedation and 10 (20.8%) underwent intravenous thrombolysis using recombinant tissue plasminogen activator before MT. The median number of retrieval passes using Solitaire was 2 (IQR: ;1e 3). The median duration from onset to recanalization was 493.5 minutes (IQR: 383.6e850.0 minutes), and the median procedure duration was 83.5 minutes (IQR: 60.0e128.5 minutes). Forty-five patients (93.8%) achieved successful recanalization with an mTICI score of 3, 3 patients (6.2%) had an mTICI score of 2b after the procedure, and 2 patients (4.2%) had their vessels perforated. PComA patency was observed in 31 patients (64.6%). During the procedure, 17 patients (35.4%) underwent angioplasty after MT; of these, 6 underwent balloon dilation and 11 underwent Apollo stent placement. Twenty-eight patients (58.3%) had residual stenosis, and the median residual stenosis rate was 75%. To sustain recanalization, tirofiban was used in 27 patients (56.3%) during and/or after the procedure. According to the TOAST classification, the etiology of stroke was large-vessel atherosclerosis in 29 patients (60.4%), cardioembolic in 16 (33.3%), and undetermined in 3 (6.3%).10 SICH occurred in 8 patients (11.8%), and all cases of
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ORIGINAL ARTICLE HONG-FEI SANG ET AL.
MT USING SOLITAIRE IN AIS WITH VBO
Table 3. Multivariable Logistic Regression for Predictors of Good Outcomes Patient Characteristics
OR
95% CI
P Value
Baseline NIHSS score
1.075
0.960e1.204
0.21
Conscious sedation
1.543
0.209e11.373
0.67
PComA patency
0.164
0.034e0.785
0.02*
pc-ASPECTS
0.406
0.184e0.895
0.03*
OR, odds ratio; CI, confidence interval; NIHSS, National Institutes of Health Stroke Scale; PComA, posterior communicating artery; pc-ASPECTS, posterior circulation Alberta Stroke Program Early CT Score. *P < 0.05.
SICH (parenchymal hematoma 2 subtype) occurred in the severe group. The median NIHSS score at 24 hours after MT was 10 (IQR: 2.3e23.0). A summary of the patients’ clinical and periprocedural characteristics is presented in Table 1. In total, 60.4% of patients were treated by combined methods; patient clinical and treatment details are shown in Table 2.
Factors Associated with Good Clinical Outcome In univariate analysis, patients with good clinical outcome had a lower baseline NIHSS score and greater baseline pc-ASPECTS than those with poor clinical outcome. The PComA patency rate was greater in patients with functional independence than in those with dependence at 90 days. Two other factors helped predict a good clinical outcome. These were conscious sedation and lower NIHSS score at 24 hours after the procedure (Table 1). Multivariate analysis showed that baseline pc-ASPECTS and PComA patency were independent predictors of good outcome at 90 days (Table 3). Good functional outcome was reached in 25 of
Figure 2. Distribution of the modified Rankin scale (mRS) score at 90 days stratified by Posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS), posterior communicating artery
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35 patients (71.4%) with pc-ASPECTS of 9 at admission and in 4 of 13 patients (30.8%) with pc-ASPECTS of <9 (Figure 2). DISCUSSION In the present study, 48 patients underwent MT using Solitaire after acute VBO in posterior circulation, and 35.4% of the patients received rescue therapy. We achieved greater successful revascularization rates (100.0% vs. 69.8%), good clinical outcomes (60.4% vs. 20%e24%), and lower mortality rates (20.8% vs. 50%e 56%) than a previous study in which patients underwent intravenous or intra-arterial thrombolytic therapy.11 This is considerably greater than the rate of 25.7% achieved in the group of patients receiving intra-arterial thrombolytic therapy in the BASICS registry completed in 2007.9 Our results were better than those of recent studies on patients with acute posterior circulation stroke who underwent MT (at 90 days, the following were obtained: recanalization rate: approximately 80%, good clinical outcome: in approximately 30% of patients, and mortality rate: 21%e 33%).12 Our results indicate the effectiveness and safety of MT
(PComA) patency, anesthesia type, baseline National Institutes of Health Stroke Scale (NIHSS) score, and 24-hour NIHSS score.
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MT USING SOLITAIRE IN AIS WITH VBO
using Solitaire for restoring blood flow and improving clinical outcomes after acute VBO and rescue therapy is readily required and employed. A meta-analysis of 5 randomized controlled trials published in 2015 showed that 46.0% of patients in the intra-arterial group had mRS scores of 0e2 after 3 months.13 This value is comparable with our results, which is remarkable because the baseline NIHSS score was greater and the prognosis was worse based on the natural history of acute posterior circulation occlusion. Accordingly, the clinical outcome obtained in our study is completely acceptable. Some studies have investigated predictors of good clinical outcome after procedures for patients with acute posterior circulation occlusion. However, the results are inconsistent.14,15 In the present study, there was no significant correlation between successful recanalization and clinical outcome. Some studies have shown that the status of the collateral vessel influences recanalization and clinical outcomes in patients with acute anterior circulation stroke.16,17 Our study demonstrated that PComA patency has a positive influence on good clinical outcome. This was in accordance with results from previous studies that acute BA occlusion with a good status of the collateral vessel at baseline can benefit from MT.18,19 Other authors detecting the effect of collateral vessels on clinical outcome did not find such a correlation; this discrepancy might be due to heterogeneous scores used to evaluate the status of collateral vessels.6,20 The posterior circulation has some peculiar anatomical characteristics, such as PComA patency and posterior inferior cerebellar arteryesuperior cerebellar artery anastomosis, which may give rise to lower dependency, maintain the vital function of the brainstem for a considerable duration, and prolong the time window for recanalization in case of acute VBO.21 The present study also showed that the pc-ASPECTS is an independent predictor of good functional outcome in patients with acute VBO who underwent MT using Solitaire, which was in agreement with the result of a previous study.22 However, some studies failed to show a significant relationship between pcASPECTS and clinical outcome.23,24 The possible reasons for the different results may be due to different patient selection criteria and different pathologic mechanisms of stroke considered among different studies. Patients with poor clinical outcomes after stent retrieval at 90 days had longer mean procedure durations than those with good outcome (101 minutes vs. 73 minutes). In situ thrombosis of large intracranial arteries caused by atherosclerotic stenosis is
REFERENCES 1. Pfefferkorn T, Mayer TE, Opherk C, et al. Staged escalation therapy in acute basilar artery occlusion: intravenous thrombolysis and on-demand consecutive endovascular mechanical thrombectomy: preliminary experience in 16 patients. Stroke. 2008;39:1496-1500.
2. Berkhemer OA, Fransen PS, Beumer D, et al. A randomized trial of intraarterial treatment for acute ischemic stroke. N Engl J Med. 2015;372: 11-20.
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particularly prevalent in Asian populations, and the incidence of underlying intracranial atherosclerosis in acute VBO was 60.4% in our study. Thrombi originating from ulcerated atherosclerotic plaques are usually stick and may require repeat thrombectomy.25 In our results, the factor making the procedure more complicated may be the higher-graded stenosis in patients with severe neurologic deficits. Intracranial atherosclerosis/stenosis is likely to be associated with re-occlusion after stent retrieval, and rescue treatments such as angioplasty with balloon dilation and/or stenting are always used.26,27 These procedures may sustain vascular recanalization but increase the risk of complications due to the occlusion and avulsion of small penetrating branches from the major artery.28 Owing to the high rate of residual stenosis even after MT, 60.4% of the patients underwent intra-arterial infusion of tirofiban to avoid reocclusion. In the present study, no significant relationship was found between tirofiban use and clinical outcome, suggesting that tirofiban use might be safe to avoid reocclusion of stenosed vessels during procedure. Compared with the rate of SICH occurrence in the BASICS registry, the rate in our study is much lower, possibly reflecting the modern IAT devices and techniques and the experienced neurointerventionalists who are acquainted with these procedures. This study has all the limitations of an observational study. This was a single-center study with a small sample size. However, we did not have strict restrictions, such as the therapeutic time window and periprocedure medication, for IAT; therefore, our cohort might have a good representation of the real world. Moreover, this was a single-arm study, and we had few patients with acute VBO not undergoing MT. To the best of our knowledge, there are 3 activated randomized controlled trials, BASICS (NCT01717755), BEST (Acute Basilar Artery Occlusion: Endovascular Interventions vs. Standard Medical Treatment; NCT02441556), and BAOCHE (Basilar Artery Occlusion Chinese Endovascular Trial; NCT02737189), which aim to confirm the effectiveness and safety of IAT for patients with AIS and BA occlusion. We hope that the data from these trials provide better management protocols for these patients. To conclude, we demonstrated that MT using Solitaire can be used to treat Chinese patients with acute VBO within 24 hours of symptom onset. We emphasized that rescue therapy was readily required and employed. PComA patency and greater initial pcASPECTS were 2 significant predictors of good outcome in these patients prognostically.
3. Saver JL, Goyal M, Bonafe A, et al. Stent-retriever thrombectomy after intravenous t-PA vs. t-PA alone in stroke. N Engl J Med. 2015;372:2285-2295.
occlusion in the modern era: a single institution experience. Neuroradiology. 2018;60:1-9.
4. Goyal M, Demchuk AM, Menon BK, et al. Randomized assessment of rapid endovascular treatment of ischemic stroke. N Engl J Med. 2015; 372:1019-1030.
7. Luo G, Mo D, Tong X, et al. Factors associated with 90-day outcomes of patients with acute posterior circulation stroke treated by mechanical thrombectomy. World Neurosurg. 2018;109: e318-e328.
5. Huo X, Gao F, Sun X, et al. Endovascular mechanical thrombectomy with the solitaire device for the treatment of acute basilar artery occlusion. World Neurosurg. 2016;89:301-308. 6. Li C, Zhao W, Wu C, et al. Outcome of endovascular treatment for acute basilar artery
8. Castaño C, Dorado L, Guerrero C, et al. Mechanical thrombectomy with the solitaire AB device in large artery occlusions of the anterior circulation: a pilot study. Stroke. 2010;41: 1836-1840.
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9. Schonewille WJ, Wijman CAC, Michel P, et al. Treatment and outcomes of acute basilar artery occlusion in the Basilar Artery International Cooperation Study (BASICS): a prospective registry study. Lancet Neurol. 2009;8:724-730. 10. Adams HP Jr, Bendixen BH, Kappelle LJ, et al. Classification of subtype of acute ischemic stroke. Definitions for use in a multicenter clinical trial. TOAST. Trial of Org 10172 in Acute Stroke Treatment. Stroke. 1993;24:35-41. 11. Jung S, Mono ML, Fischer U, et al. Three-month and long-term outcomes and their predictors in acute basilar artery occlusion treated with intraarterial thrombolysis. Stroke. 2011;42:1946-1951. 12. Phan K, Phan S, Huo YR, et al. Outcomes of endovascular treatment of basilar artery occlusion in the stent retriever era: a systematic review and meta-analysis. J Neurointerv Surg. 2016;8:1107-1115. 13. Goyal M, Menon BK, van Zwam WH, et al. Endovascular thrombectomy after large-vessel ischaemic stroke: a meta-analysis of individual patient data from five randomised trials. Lancet. 2016;387:1723-1731. 14. Gory B, Mazighi M, Labreuche J, et al. Predictors for mortality after mechanical thrombectomy of acute basilar artery occlusion. Cerebrovasc Dis. 2018; 45:61-67. 15. Bouslama M, Haussen DC, Aghaebrahim A, et al. Predictors of good outcome after endovascular therapy for vertebrobasilar occlusion stroke. Stroke. 2017;48:3252-3257. 16. Berkhemer OA, Jansen IG, Beumer D, et al. Collateral status on baseline computed
MT USING SOLITAIRE IN AIS WITH VBO
tomographic angiography and intra-arterial treatment effect in patients with proximal anterior circulation stroke. Stroke. 2016;47:768-776. 17. Bang OY, Saver JL, Kim SJ, et al. Collateral flow predicts response to endovascular therapy for acute ischemic stroke. Stroke. 2011;42:693-699. 18. van de Hoeven EJ, Mcverry F, Vos JA, et al. Collateral flow predicts outcome after basilar artery occlusion: the posterior circulation collateral score. Int J Stroke. 2016;11:768-775. 19. Alemseged F, Shah DG, Diomedi M, et al. The basilar artery on computed tomography angiography prognostic score for basilar artery occlusion. Stroke. 2017;48:631-637. 20. van Houwelingen RC, Luijckx GJ, Uyttenboogaart M. Intra-arterial treatment for basilar artery occlusion-reply. JAMA Neurol. 2016; 74:130-131. 21. Lindsberg PJ, Pekkola J, Strbian D, et al. Time window for recanalization in basilar artery occlusion: speculative synthesis. Neurology. 2015;85: 1806-1815. 22. Zhang X, Luo G, Mo D, et al. Predictors of good outcome after endovascular treatment for patients with vertebrobasilar artery occlusion due to intracranial atherosclerotic stenosis [e-pub ahead of print]. Clin Neuroradiol. 2018. https://doi.org/ 10.1007/s00062-018-0731-z. 23. Mohlenbruch M, Stampfl S, Behrens L, et al. Mechanical thrombectomy with stent retrievers in acute basilar artery occlusion. AJNR Am J Neuroradiol. 2014;35:959-964.
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24. Karameshev A, Arnold M, Schroth G, et al. Diffusion-weighted MRI helps predict outcome in basilar artery occlusion patients treated with intraarterial thrombolysis. Cerebrovasc Dis. 2011;32: 393-400. 25. Mordasini P, Brekenfeld C, Byrne JV, et al. Technical feasibility and application of mechanical thrombectomy with the solitaire FR revascularization device in acute basilar artery occlusion. AJNR Am J Neuroradiol. 2013;34:159-163. 26. Bang OY. Intracranial atherosclerosis: current understanding and perspectives. J Stroke. 2014;16: 27-35. 27. Lee JS, Hong JM, Lee KS, et al. Primary stent retrieval for acute intracranial large artery occlusion due to atherosclerotic disease. J Stroke. 2015; 18:96-101. 28. Jiang WJ, Suh DC, Wang Y, et al. Angioplasty and Stenting. West Sussex, UK: Wiley-Blackwell; 2001. Conflict of interest statement: This study was supported by Zhejiang Provincial Natural Science Foundation of China (GF18H090036) and Hangzhou Science and Technology Plan Guiding Project (20181228Y01). Received 8 March 2019; accepted 17 April 2019 Citation: World Neurosurg. (2019). https://doi.org/10.1016/j.wneu.2019.04.152 Journal homepage: www.journals.elsevier.com/worldneurosurgery Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2019 Elsevier Inc. All rights reserved.
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Mechanical Thrombectomy Using Solitaire in Acute Ischemic Stroke Patients with Vertebrobasilar Occlusion: A Prospective Observational Study Hong-Fei Sang, Cong-Guo Yin, Wen-Qing Xia, Huan Huang, Ke-Qin Liu, Tian-Wen Chen, Xiao-Li Si, Lin Jiang
BACKGROUND: The safety and effectiveness of endovascular mechanical thrombectomy in patients with acute vertebrobasilar occlusion (VBO) are debatable and undergoing evaluation. We report the clinical outcome and prognostic factors in a prospective cohort of acute ischemic stroke patients with VBO.
-
METHODS: In total, 48 consecutive patients with acute VBO underwent mechanical thrombectomy using Solitaire. We analyzed clinical and imaging data and searched for predictors of good clinical outcome (modified Rankin scale score: 0e3).
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RESULTS: The median prethrombectomy National Institutes of Health Stroke Scale score was 22.0. The median duration from symptom onset to recanalization was 493.5 minutes. A total of 35.4% of the patients received rescue therapy. Recanalization (modified Thrombolysis In Cerebral Infarction: 2be3) was successful in all patients. Clinically relevant intracranial hemorrhage was observed in 2 patients. After 90 days, good outcomes were obtained in 27 patients. The baseline National Institutes of Health Stroke Scale score, posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS), anesthesia type, and posterior communicating artery (PComA) patency were significantly associated with outcomes at 90 days in univariate analysis. Multivariate logistic regression indicated
that high pc-ASPECTS at admission and PComA patency were independent predictors of good outcome at 90 days. CONCLUSIONS: Up to 60.4% of the patients reached good outcomes after endovascular treatment and 35.4% of the patients received rescue therapy, suggesting that mechanical thrombectomy using Solitaire in patients with stroke with VBO is safe and effective and that rescue therapy is readily required and employed. High baseline pc-ASPECTS and PComA patency were associated with better outcomes after thrombectomy in these patients.
-
-
Key words Acute ischemic stroke - Endovascular treatment - Mechanical thrombectomy - Posterior circulation - Vertebrobasilar occlusion -
Abbreviations and Acronyms AIS: Acute ischemic stroke BA: Basilar artery BASICS: Basilar Artery International Cooperation Study IAT: intra-arterial therapy ICH: intracerebral hemorrhage IQR: interquartile range mRS: Modified Rankin scale score MT: Mechanical thrombectomy mTICI: Modified thrombolysis in cerebral infarction score NIHSS: National Institutes of Health Stroke Scale
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INTRODUCTION cute ischemic stroke (AIS) caused by vertebrobasilar occlusion (VBO) accounts for approximately 20% of all cases of ischemic stroke; however, it is the most devastating type of stroke, having mortality and disability rates of up to 90% in the absence of recanalization.1 Conclusive evidence from several recent randomized controlled trials have suggested that stent retriever thrombectomy improves the outcome of patients with AIS with anterior circulation large-vessel occlusion.2-4 However, the safety and effectiveness are less clear in patients with stroke with acute VBO. To date, to the best of our knowledge, there are no data from randomized controlled trials comparing intravenous
A
pc-ASPECTS: Posterior circulation Acute Stroke Prognosis Early CT Score PComA: Posterior communicating artery SICH: symptomatic intracerebral hemorrhage TOAST: Trial of ORG 10172 in Acute Stroke Treatment VBO: Vertebrobasilar occlusion Department of Neurology, Hangzhou First People’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, P.R. China To whom correspondence should be addressed: Lin Jiang, M.D. [E-mail: [email protected]] Hong-Fei Sang and Cong-Guo Yin contributed equally to this article and are coefirst authors. Citation: World Neurosurg. (2019). https://doi.org/10.1016/j.wneu.2019.04.152 Journal homepage: www.journals.elsevier.com/world-neurosurgery Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2019 Elsevier Inc. All rights reserved.
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ORIGINAL ARTICLE HONG-FEI SANG ET AL.
MT USING SOLITAIRE IN AIS WITH VBO
Table 1. Baseline, Procedural, and Outcome Parameters Patient Characteristics
Overall (n [ 48)
Good Outcome (n [ 29)
Poor Outcome (n [ 19)
P Value
Age, years, median (IQR)
70.5 (62.0e80.0)
67.0 (60.5e80.0)
79.0 (63.0e80.0)
0.237
Female, % (n) Baseline NIHSS score, median (IQR) pc-ASPECTS, median (IQR)
25.0 (12/48)
20.7 (6/29)
31.6 (6/19)
0.501
22.0 (12.5e26.0)
19.0 (9.0e23.0)
25.0 (22.0e27.0)
0.002*
9.0 (8.0e10.0)
9.0 (9.0e10.0)
9.0 (7.0e9.0)
0.005*
37.5 (18/48)
41.4 (12/29)
31.6 (6/19)
Occlusion site, % (n)
0.588
Distal BA Mid-BA
16.7 (8/48)
13.8 (4/29)
21.1 (4/19)
Proximal BA
35.4 (17/48)
30.1 (9/29)
42.1 (8/19)
VA
10.4 (5/48)
13.8 (4/29)
5.3 (1/19)
Atrial fibrillation, % (n)
43.8 (21/48)
34.5 (10/29)
57.9 (11/19)
0.110
Hypertension, % (n)
72.9 (35/48)
69.0 (20/29)
78.9 (15/19)
0.447
Diabetes, % (n)
16.7 (8/48)
13.8 (4/29)
21.1 (4/19)
0.695
IHD, % (n)
4.2 (2/48)
3.4 (1/29)
5.3 (1/19)
1.000
Previous stroke/TIA, % (n)
12.5 (6/48)
10.3 (3/29)
15.8 (3/19)
0.669
Hyperlipidemia, % (n)
20.8 (10/48)
13.8 (4/29)
31.6 (6/19)
0.164
TOAST, % (n)
0.256
Atherosclerosis
60.4 (29/48)
62.1 (18/29)
57.9 (11/19)
Cardioembolic
33.3 (16/48)
27.6 (8/29)
42.1 (8/19)
6.3 (3/48)
10.3 (3/29)
0.0 (0/19)
Conscious sedation, % (n)
85.4 (41/48)
93.1 (27/29)
73.7 (14/19)
0.097*
IV rt-PA, % (n)
20.8 (10/48)
20.7 (6/29)
21.1 (4/19)
1.000
Others Reperfusion therapy
Number of retrieval passes, median (IQR)
2.0 (1.0e3.0)
2.0 (1.0e3.0)
2.0 (1.0e3.0)
0.665
Procedure duration, minutes, median (IQR)
83.5 (60.0e128.5)
73.0 (58.0e103.5)
101.0 (67.0e144.0)
0.114
493.5 (383.6e850.0)
470.0 (376.5e852.0)
510.0 (380.0e867.0)
0.975
mTICI, score ¼ 3, % (n)
Onset to recanalization duration, minutes, median (IQR)
93.8 (45/48)
96.6 (28/29)
89.5 (17/19)
0.554
Vessel perforation, % (n)
4.2 (2/48)
6.9 (2/29)
0.0 (0/19)
0.512
PComA patency, % (n)
64.6 (31/48)
79.3 (23/29)
42.1 (8/19)
0.008*
Balloon angioplasty or stenting, % (n)
35.4 (17/48)
27.6 (8/29)
47.4 (9/19)
0.161
Residual stenosis, % (n)
58.3 (28/48)
58.6 (17/29)
57.2 (11/19)
0.960
75.0 (0.0e90.0)
50.0 (0.0e90.0)
90.0 (0.0e90.0)
0.474
Tirofiban, % (n)
56.3 (27/48)
55.2 (16/29)
57.9 (11/19)
0.853
Any ICH, % (n)
16.7 (8/48)
17.2 (5/29)
15.8 (3/19)
1.000
SICH, PH-2 decline, % (n)
4.2 (2/48)
0.0 (0/29)
10.5 (2/19)
0.152
10.0 (2.3e23.0)
5.0 (2.0e11.0)
25.0 (18.0e27.0)
<0.001*
Residual stenosis rate, median (IQR)
24-hour NIHSS score, median (IQR)
The P value was calculated by the c test for categorial variables and ManneWhitney U test for continuous variables. IQR, interquartile range; NIHSS, National Institutes of Health Stroke Scale; pc-ASPECTS, posterior circulation Alberta Stroke Program Early CT Score; BA, basilar artery; VA, vertebral artery; IHD, ischemic heart disease; TIA, transient ischemic attack; TOAST, Trial of ORG 10172 in Acute Stroke Treatment; IV, intravenous; rt-PA, recombinant tissue plasminogen activator; mTICI, Modified Thrombolysis In Cerebral Infarction; PComA, posterior communicating artery; ICH, intracerebral hemorrhage; SICH, symptomatic intracerebral hemorrhage; PH, parenchymal hematoma. *P < 0.05. 2
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ORIGINAL ARTICLE HONG-FEI SANG ET AL.
MT USING SOLITAIRE IN AIS WITH VBO
Figure 1. Distribution of the modified Rankin scale (mRS) score for all patients at 90 days.
thrombolysis with intra-arterial therapy (IAT) in patients with AIS with VBO. In the past decade, case series and observational studies have described using IAT for patients with acute basilar artery (BA) occlusion. These studies have suggested that patients with acute posterior circulation stroke also benefit from IAT. However, data on IAT in Chinese patients with AIS and VBO are insufficient.5-8 Therefore, the objective of the present study was to evaluate the effectiveness and safety of modern mechanical thrombectomy (MT) using Solitaire (ev3, Irvine, California, USA) for acute VBO among Chinese patients with AIS and to identify prognostic factors that may influence the clinical outcome.
METHODS Study Design and Patients This prospective study enrolled 48 consecutive patients with AIS confirmed to have acute VBO at the Department of Neurology of Hangzhou First People’s Hospital between January 1, 2016, and July 15, 2018. Hangzhou First People’s Hospital is affiliated to Zhejiang University and is a comprehensive stroke center in eastern China. This study was reviewed and approved by the local institutional review board. Written informed consent was obtained from the patients or their legal representatives before participating. Patients who were aged 18 years and presented with stroke due to acute VBO within 24 hours that was confirmed by computed tomography angiography or magnetic resonance angiography posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS) score 6, baseline National Institutes of Health Stroke Scale (NIHSS) score 6 were eligible to participate. Wake-up stroke onset was calculated from the last normal time to the time of discovery, less than 24 hours. The exclusion criteria were as follows: 1) intracerebral hemorrhage when noncontrastenhanced computed tomography was performed at admission; 2) history of intracerebral hemorrhage, subarachnoid hemorrhage, arteriovenous malformation, or tumor; 3) pre-existing dependency with modified Rankin Scale (mRS) score of 3; 4) pc-ASPECTS
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score <6; and 5) renal failure as indicated by serum creatinine levels of >2.0 mg/dL (177 mmol/L). Clinical Assessment Clinical and radiologic data were prospectively collected. Demographic characteristics, cerebrovascular risk factors, pcASPECTS, and NIHSS score at admission were evaluated and documented by 2 neurologists. After clinical and neuroimaging evaluations, patients with acute VBO were considered eligible to undergo IAT based on the judgment of the interventional neurologists. Our protocol recommended IAT for patients with acute VBO up to 24 hours after symptom onset. Factors related to treatment outcomes were investigated. These factors were TOAST classification (Trial of ORG 10172 in Acute Stroke Treatment), anesthesia type, arterial occlusion site, collateral circulation, tirofiban usage, estimated stroke-onset duration, procedure duration, onset-to-recanalization duration, and reperfusion therapy status. A method for determining the symptom onset duration was the last known normal time. Collateral circulation is defined as the patency of posterior communicating artery (PComA). Endovascular Procedures Because Solitaire has the following advantages, e.g., it first entered the Chinese market; there are many sizes to choose from; the commonly used ones are 4 20 mm and 6 30 mm; it has no head end and the safety is greater; and its invalid area is short, this study used Solitaire as a first-line treatment. All patients underwent IAT using Solitaire combined with or without additional angioplasty for reperfusion either directly or after intravenous thrombolysis with recombinant tissue plasminogen activator. All interventions were performed by experienced neurointerventionalists on a biplane system in a neuroangiography suite with the patient under conscious sedation or general anesthesia. When MT using Solitaire failed to achieve successful reperfusion in patients (modified Thrombolysis In Cerebral Infarction Score [mTICI] score: 0e2a), the neurointerventionalists switched to
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MT USING SOLITAIRE IN AIS WITH VBO
Table 2. Details of Patients Who Were Treated by a Combined Method Patient Characteristics Age, years, median (IQR) Male, % (n) Baseline NIHSS score, median (IQR) pc-ASPECTS, median (IQR)
67.0 (60.5e78.0) 86.2 (25/29) 22.0 (11.5e27.0) 9.0 (8.0e10.0)
Occlusion site, % (n) Distal BA
13.8 (4/29)
Mid-BA
17.2 (5/29)
Proximal BA
51.7 (15/29)
VA
17.2 (5/29)
TOAST, % (n) Atherosclerosis Others
93.1 (27/29) 6.9 (2/29)
Reperfusion therapy IV rt-PA, % (n)
20.7 (6/29)
Number of retrieval passes, median (IQR)
2.0 (1.0e3.0)
Procedure duration, minutes, median (IQR)
101.0 (67.5e141.0)
Onset to recanalization duration, minutes, median (IQR)
569.0 (417.0e833.0)
Outcome Measures In accordance with the Basilar Artery International Cooperation Study (BASICS) registry, stroke severity was dichotomized as severe or mild-to-moderate.9 The primary outcome was a good 90day outcome defined as an mRS score of 0e3. The mRS score at 90 days was assessed by 2 independent trained neurologists who were unaware of treatment information during face-to-face interviews. Other outcomes included successful recanalization with an mTICI score of 2b or 3 and symptomatic intracerebral hemorrhage (SICH). SICH was defined as hemorrhage on the follow-up computed tomography/magnetic resonance imaging scan associated with an increase of the NIHSS score by 4. Statistical Analysis Statistical analyses were performed using IBM SPSS Statistics 21 (IBM Corp., Armonk, New York, USA). Baseline data of categorical variables were described using frequencies and proportions, whereas continuous variables were described using mean (standard deviation) or median (interquartile range [IQR]: 25%e75%). Patients with good outcomes were compared with those with poor outcomes. The c2 test or Fisher exact test was used for categorical variables, and the Student t test or ManneWhitney U test was used for continuous variables. Multivariate logistic regression analysis for predictors of good clinical outcome was performed for all variables significant at P < 0.1 in the univariate analysis. A P value of <0.05 was considered significant.
mTICI, score ¼ 3, % (n)
89.6 (26/29)
RESULTS
PComA patency, % (n)
68.9 (20/29)
Balloon angioplasty, % (n) Stenting, % (n)
20.7 (6/29) 37.9 (11/29)
Tirofiban, % (n)
93.1 (27/29)
Any ICH, % (n)
20.7 (6/29)
Baseline Characteristics There were 36 male and 12 female patients, with a mean age of 70.5 years. The median NIHSS score and pc-ASPECTS at admission are shown in Table 1. The occlusion sites confirmed by angiography also are presented in Table 1. In total, 29 patients (60.4%) reached a good clinical outcome at 90 days (Figure 1).
SICH, PH-2 decline, % (n)
6.9 (2/29)
24-hour NIHSS score, median (IQR) mRS score after 3months (0e3), % (n)
13.0 (2.0e22.0) 62.1% (18/29)
IQR, interquartile range; NIHSS, National Institutes of Health Stroke Scale; pc-ASPECTS, posterior circulation Alberta Stroke Program Early CT Score; BA, basilar artery; VA, vertebral artery; TOAST, Trial of ORG 10172 in Acute Stroke Treatment; IV, intravenous; rt-PA, recombinant tissue plasminogen activator; mTICI, Modified Thrombolysis In Cerebral Infarction; PComA, posterior communicating artery; ICH, intracerebral hemorrhage; SICH, symptomatic intracerebral hemorrhage; PH, parenchymal hematoma; mRS, modified Rankin scale.
either balloon or stent percutaneous transluminal angioplasty. mTICI scores were estimated from angiographic runs before and after the procedure. Angiographic images were assessed, and 2 trained neuroradiologists reached a consensus. Tirofiban, which is a fast-acting glycoprotein IIb/IIIa inhibitor that prevents platelet aggregation and improves cerebral perfusion, was intravenously administered in patients undergoing stent-assisted angioplasty at a first dose of 6.7 mg/kg and continued at a dosage of 0.08 mg/kg/ min for 24 hours.
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Periprocedural Characteristics Among the 48 patients, 41 (85.4%) were treated under conscious sedation and 10 (20.8%) underwent intravenous thrombolysis using recombinant tissue plasminogen activator before MT. The median number of retrieval passes using Solitaire was 2 (IQR: ;1e 3). The median duration from onset to recanalization was 493.5 minutes (IQR: 383.6e850.0 minutes), and the median procedure duration was 83.5 minutes (IQR: 60.0e128.5 minutes). Forty-five patients (93.8%) achieved successful recanalization with an mTICI score of 3, 3 patients (6.2%) had an mTICI score of 2b after the procedure, and 2 patients (4.2%) had their vessels perforated. PComA patency was observed in 31 patients (64.6%). During the procedure, 17 patients (35.4%) underwent angioplasty after MT; of these, 6 underwent balloon dilation and 11 underwent Apollo stent placement. Twenty-eight patients (58.3%) had residual stenosis, and the median residual stenosis rate was 75%. To sustain recanalization, tirofiban was used in 27 patients (56.3%) during and/or after the procedure. According to the TOAST classification, the etiology of stroke was large-vessel atherosclerosis in 29 patients (60.4%), cardioembolic in 16 (33.3%), and undetermined in 3 (6.3%).10 SICH occurred in 8 patients (11.8%), and all cases of
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ORIGINAL ARTICLE HONG-FEI SANG ET AL.
MT USING SOLITAIRE IN AIS WITH VBO
Table 3. Multivariable Logistic Regression for Predictors of Good Outcomes Patient Characteristics
OR
95% CI
P Value
Baseline NIHSS score
1.075
0.960e1.204
0.21
Conscious sedation
1.543
0.209e11.373
0.67
PComA patency
0.164
0.034e0.785
0.02*
pc-ASPECTS
0.406
0.184e0.895
0.03*
OR, odds ratio; CI, confidence interval; NIHSS, National Institutes of Health Stroke Scale; PComA, posterior communicating artery; pc-ASPECTS, posterior circulation Alberta Stroke Program Early CT Score. *P < 0.05.
SICH (parenchymal hematoma 2 subtype) occurred in the severe group. The median NIHSS score at 24 hours after MT was 10 (IQR: 2.3e23.0). A summary of the patients’ clinical and periprocedural characteristics is presented in Table 1. In total, 60.4% of patients were treated by combined methods; patient clinical and treatment details are shown in Table 2.
Factors Associated with Good Clinical Outcome In univariate analysis, patients with good clinical outcome had a lower baseline NIHSS score and greater baseline pc-ASPECTS than those with poor clinical outcome. The PComA patency rate was greater in patients with functional independence than in those with dependence at 90 days. Two other factors helped predict a good clinical outcome. These were conscious sedation and lower NIHSS score at 24 hours after the procedure (Table 1). Multivariate analysis showed that baseline pc-ASPECTS and PComA patency were independent predictors of good outcome at 90 days (Table 3). Good functional outcome was reached in 25 of
Figure 2. Distribution of the modified Rankin scale (mRS) score at 90 days stratified by Posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS), posterior communicating artery
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35 patients (71.4%) with pc-ASPECTS of 9 at admission and in 4 of 13 patients (30.8%) with pc-ASPECTS of <9 (Figure 2). DISCUSSION In the present study, 48 patients underwent MT using Solitaire after acute VBO in posterior circulation, and 35.4% of the patients received rescue therapy. We achieved greater successful revascularization rates (100.0% vs. 69.8%), good clinical outcomes (60.4% vs. 20%e24%), and lower mortality rates (20.8% vs. 50%e 56%) than a previous study in which patients underwent intravenous or intra-arterial thrombolytic therapy.11 This is considerably greater than the rate of 25.7% achieved in the group of patients receiving intra-arterial thrombolytic therapy in the BASICS registry completed in 2007.9 Our results were better than those of recent studies on patients with acute posterior circulation stroke who underwent MT (at 90 days, the following were obtained: recanalization rate: approximately 80%, good clinical outcome: in approximately 30% of patients, and mortality rate: 21%e 33%).12 Our results indicate the effectiveness and safety of MT
(PComA) patency, anesthesia type, baseline National Institutes of Health Stroke Scale (NIHSS) score, and 24-hour NIHSS score.
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using Solitaire for restoring blood flow and improving clinical outcomes after acute VBO and rescue therapy is readily required and employed. A meta-analysis of 5 randomized controlled trials published in 2015 showed that 46.0% of patients in the intra-arterial group had mRS scores of 0e2 after 3 months.13 This value is comparable with our results, which is remarkable because the baseline NIHSS score was greater and the prognosis was worse based on the natural history of acute posterior circulation occlusion. Accordingly, the clinical outcome obtained in our study is completely acceptable. Some studies have investigated predictors of good clinical outcome after procedures for patients with acute posterior circulation occlusion. However, the results are inconsistent.14,15 In the present study, there was no significant correlation between successful recanalization and clinical outcome. Some studies have shown that the status of the collateral vessel influences recanalization and clinical outcomes in patients with acute anterior circulation stroke.16,17 Our study demonstrated that PComA patency has a positive influence on good clinical outcome. This was in accordance with results from previous studies that acute BA occlusion with a good status of the collateral vessel at baseline can benefit from MT.18,19 Other authors detecting the effect of collateral vessels on clinical outcome did not find such a correlation; this discrepancy might be due to heterogeneous scores used to evaluate the status of collateral vessels.6,20 The posterior circulation has some peculiar anatomical characteristics, such as PComA patency and posterior inferior cerebellar arteryesuperior cerebellar artery anastomosis, which may give rise to lower dependency, maintain the vital function of the brainstem for a considerable duration, and prolong the time window for recanalization in case of acute VBO.21 The present study also showed that the pc-ASPECTS is an independent predictor of good functional outcome in patients with acute VBO who underwent MT using Solitaire, which was in agreement with the result of a previous study.22 However, some studies failed to show a significant relationship between pcASPECTS and clinical outcome.23,24 The possible reasons for the different results may be due to different patient selection criteria and different pathologic mechanisms of stroke considered among different studies. Patients with poor clinical outcomes after stent retrieval at 90 days had longer mean procedure durations than those with good outcome (101 minutes vs. 73 minutes). In situ thrombosis of large intracranial arteries caused by atherosclerotic stenosis is
REFERENCES 1. Pfefferkorn T, Mayer TE, Opherk C, et al. Staged escalation therapy in acute basilar artery occlusion: intravenous thrombolysis and on-demand consecutive endovascular mechanical thrombectomy: preliminary experience in 16 patients. Stroke. 2008;39:1496-1500.
2. Berkhemer OA, Fransen PS, Beumer D, et al. A randomized trial of intraarterial treatment for acute ischemic stroke. N Engl J Med. 2015;372: 11-20.
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particularly prevalent in Asian populations, and the incidence of underlying intracranial atherosclerosis in acute VBO was 60.4% in our study. Thrombi originating from ulcerated atherosclerotic plaques are usually stick and may require repeat thrombectomy.25 In our results, the factor making the procedure more complicated may be the higher-graded stenosis in patients with severe neurologic deficits. Intracranial atherosclerosis/stenosis is likely to be associated with re-occlusion after stent retrieval, and rescue treatments such as angioplasty with balloon dilation and/or stenting are always used.26,27 These procedures may sustain vascular recanalization but increase the risk of complications due to the occlusion and avulsion of small penetrating branches from the major artery.28 Owing to the high rate of residual stenosis even after MT, 60.4% of the patients underwent intra-arterial infusion of tirofiban to avoid reocclusion. In the present study, no significant relationship was found between tirofiban use and clinical outcome, suggesting that tirofiban use might be safe to avoid reocclusion of stenosed vessels during procedure. Compared with the rate of SICH occurrence in the BASICS registry, the rate in our study is much lower, possibly reflecting the modern IAT devices and techniques and the experienced neurointerventionalists who are acquainted with these procedures. This study has all the limitations of an observational study. This was a single-center study with a small sample size. However, we did not have strict restrictions, such as the therapeutic time window and periprocedure medication, for IAT; therefore, our cohort might have a good representation of the real world. Moreover, this was a single-arm study, and we had few patients with acute VBO not undergoing MT. To the best of our knowledge, there are 3 activated randomized controlled trials, BASICS (NCT01717755), BEST (Acute Basilar Artery Occlusion: Endovascular Interventions vs. Standard Medical Treatment; NCT02441556), and BAOCHE (Basilar Artery Occlusion Chinese Endovascular Trial; NCT02737189), which aim to confirm the effectiveness and safety of IAT for patients with AIS and BA occlusion. We hope that the data from these trials provide better management protocols for these patients. To conclude, we demonstrated that MT using Solitaire can be used to treat Chinese patients with acute VBO within 24 hours of symptom onset. We emphasized that rescue therapy was readily required and employed. PComA patency and greater initial pcASPECTS were 2 significant predictors of good outcome in these patients prognostically.
3. Saver JL, Goyal M, Bonafe A, et al. Stent-retriever thrombectomy after intravenous t-PA vs. t-PA alone in stroke. N Engl J Med. 2015;372:2285-2295.
occlusion in the modern era: a single institution experience. Neuroradiology. 2018;60:1-9.
4. Goyal M, Demchuk AM, Menon BK, et al. Randomized assessment of rapid endovascular treatment of ischemic stroke. N Engl J Med. 2015; 372:1019-1030.
7. Luo G, Mo D, Tong X, et al. Factors associated with 90-day outcomes of patients with acute posterior circulation stroke treated by mechanical thrombectomy. World Neurosurg. 2018;109: e318-e328.
5. Huo X, Gao F, Sun X, et al. Endovascular mechanical thrombectomy with the solitaire device for the treatment of acute basilar artery occlusion. World Neurosurg. 2016;89:301-308. 6. Li C, Zhao W, Wu C, et al. Outcome of endovascular treatment for acute basilar artery
8. Castaño C, Dorado L, Guerrero C, et al. Mechanical thrombectomy with the solitaire AB device in large artery occlusions of the anterior circulation: a pilot study. Stroke. 2010;41: 1836-1840.
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9. Schonewille WJ, Wijman CAC, Michel P, et al. Treatment and outcomes of acute basilar artery occlusion in the Basilar Artery International Cooperation Study (BASICS): a prospective registry study. Lancet Neurol. 2009;8:724-730. 10. Adams HP Jr, Bendixen BH, Kappelle LJ, et al. Classification of subtype of acute ischemic stroke. Definitions for use in a multicenter clinical trial. TOAST. Trial of Org 10172 in Acute Stroke Treatment. Stroke. 1993;24:35-41. 11. Jung S, Mono ML, Fischer U, et al. Three-month and long-term outcomes and their predictors in acute basilar artery occlusion treated with intraarterial thrombolysis. Stroke. 2011;42:1946-1951. 12. Phan K, Phan S, Huo YR, et al. Outcomes of endovascular treatment of basilar artery occlusion in the stent retriever era: a systematic review and meta-analysis. J Neurointerv Surg. 2016;8:1107-1115. 13. Goyal M, Menon BK, van Zwam WH, et al. Endovascular thrombectomy after large-vessel ischaemic stroke: a meta-analysis of individual patient data from five randomised trials. Lancet. 2016;387:1723-1731. 14. Gory B, Mazighi M, Labreuche J, et al. Predictors for mortality after mechanical thrombectomy of acute basilar artery occlusion. Cerebrovasc Dis. 2018; 45:61-67. 15. Bouslama M, Haussen DC, Aghaebrahim A, et al. Predictors of good outcome after endovascular therapy for vertebrobasilar occlusion stroke. Stroke. 2017;48:3252-3257. 16. Berkhemer OA, Jansen IG, Beumer D, et al. Collateral status on baseline computed
MT USING SOLITAIRE IN AIS WITH VBO
tomographic angiography and intra-arterial treatment effect in patients with proximal anterior circulation stroke. Stroke. 2016;47:768-776. 17. Bang OY, Saver JL, Kim SJ, et al. Collateral flow predicts response to endovascular therapy for acute ischemic stroke. Stroke. 2011;42:693-699. 18. van de Hoeven EJ, Mcverry F, Vos JA, et al. Collateral flow predicts outcome after basilar artery occlusion: the posterior circulation collateral score. Int J Stroke. 2016;11:768-775. 19. Alemseged F, Shah DG, Diomedi M, et al. The basilar artery on computed tomography angiography prognostic score for basilar artery occlusion. Stroke. 2017;48:631-637. 20. van Houwelingen RC, Luijckx GJ, Uyttenboogaart M. Intra-arterial treatment for basilar artery occlusion-reply. JAMA Neurol. 2016; 74:130-131. 21. Lindsberg PJ, Pekkola J, Strbian D, et al. Time window for recanalization in basilar artery occlusion: speculative synthesis. Neurology. 2015;85: 1806-1815. 22. Zhang X, Luo G, Mo D, et al. Predictors of good outcome after endovascular treatment for patients with vertebrobasilar artery occlusion due to intracranial atherosclerotic stenosis [e-pub ahead of print]. Clin Neuroradiol. 2018. https://doi.org/ 10.1007/s00062-018-0731-z. 23. Mohlenbruch M, Stampfl S, Behrens L, et al. Mechanical thrombectomy with stent retrievers in acute basilar artery occlusion. AJNR Am J Neuroradiol. 2014;35:959-964.
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24. Karameshev A, Arnold M, Schroth G, et al. Diffusion-weighted MRI helps predict outcome in basilar artery occlusion patients treated with intraarterial thrombolysis. Cerebrovasc Dis. 2011;32: 393-400. 25. Mordasini P, Brekenfeld C, Byrne JV, et al. Technical feasibility and application of mechanical thrombectomy with the solitaire FR revascularization device in acute basilar artery occlusion. AJNR Am J Neuroradiol. 2013;34:159-163. 26. Bang OY. Intracranial atherosclerosis: current understanding and perspectives. J Stroke. 2014;16: 27-35. 27. Lee JS, Hong JM, Lee KS, et al. Primary stent retrieval for acute intracranial large artery occlusion due to atherosclerotic disease. J Stroke. 2015; 18:96-101. 28. Jiang WJ, Suh DC, Wang Y, et al. Angioplasty and Stenting. West Sussex, UK: Wiley-Blackwell; 2001. Conflict of interest statement: This study was supported by Zhejiang Provincial Natural Science Foundation of China (GF18H090036) and Hangzhou Science and Technology Plan Guiding Project (20181228Y01). Received 8 March 2019; accepted 17 April 2019 Citation: World Neurosurg. (2019). https://doi.org/10.1016/j.wneu.2019.04.152 Journal homepage: www.journals.elsevier.com/worldneurosurgery Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2019 Elsevier Inc. All rights reserved.
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