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Outcomes of manual aspiration thrombectomy for acute ischemic stroke refractory to stent-based thrombectomy Seul Kee Kim,1 Woong Yoon,1 Sung Min Moon,1 Man Seok Park,2 Gwang Woo Jeong,l Heoung Keun Kang1 1
Department of Radiology, Chonnam National University Medical School, Chonnam National University Hospital, Gwangju, Republic of Korea 2 Department of Neurology, Chonnam National University Medical School, Chonnam National University Hospital, Gwangju, Republic of Korea Correspondence to Professor Woong Yoon, Department of Radiology, Chonnam National University Hospital, 671 Jebong-Ro, Dong-gu, Gwangju 501-757, Republic of Korea; [email protected]
Received 7 March 2014 Revised 14 April 2014 Accepted 15 April 2014 Published Online First 8 May 2014
ABSTRACT Background and purpose The optimal treatment for patients with acute stroke refractory to stent-based thrombectomy (SBT) is unclear. This study aimed to report clinical outcomes of manual aspiration thrombectomy (MAT) for the treatment of acute ischemic stroke refractory to SBT. Methods We retrospectively analyzed clinical and angiographic data of 30 patients who underwent MAT with a Penumbra reperfusion catheter because of refractory occlusion after SBT with a Solitaire stent as ﬁrst-line endovascular therapy. Refractory occlusion was deﬁned by a lack of successful revascularization (deﬁned as Thrombolysis In Cerebral Infarction ≥2b) after ﬁve retrieval attempts. A good outcome was deﬁned as a modiﬁed Rankin scale score of ≤2 at 3 months. Results Successful revascularization was achieved in 83.3% (25/30) of the patients who underwent MAT after failed SBT. There was no arterial rupture or dissection or symptomatic intracranial hemorrhage. Two embolic occlusions in a new arterial territory and ﬁve subarachnoid hemorrhages occurred, neither of which caused neurological worsening. At the 3-month followup, 36.7% (11/30) of patients exhibited a good outcome. The mortality rate was 6.7% (2/30) at 3 months. Conclusions This study suggests that MAT with the Penumbra reperfusion catheter can further increase the revascularization rate without serious complications in patients with acute stroke with refractory occlusions after SBT with a Solitaire stent.
To cite: Kim SK, Yoon W, Moon SM, et al. J NeuroIntervent Surg 2015;7:473–477.
Mechanical thrombectomy with a stent-type thrombectomy device is increasingly used as ﬁrst-line endovascular therapy for the treatment of acute ischemic stroke secondary to an intracranial large vessel occlusion. Randomized controlled trials and several case series have demonstrated the efﬁcacy of stent-based thrombectomy (SBT) in the recanalization of occluded cerebral arteries.1–4 However, failure of SBT to achieve successful revascularization has been reported in 20–30% of treated cases.1–4 Rescue therapy for patients with an intracranial large vessel occlusion refractory to SBT include the use of an alternative mechanical device, intra-arterial thrombolysis, or mechanical clot disruption with a microguidewire.1–3 Manual aspiration thrombectomy (MAT) using a ﬂexible aspiration catheter is another mechanical thrombectomy technique for treating
acute ischemic stroke.5–7 Recent studies suggest that MAT with the newest generation of large-bore aspiration catheters is a promising technique that can reduce procedure times and provide superior costeffective value, with primary revascularization rates similar to SBT.8 9 Applying a different thrombectomy technique such as MAT may be a solution for persistent arterial occlusions in cases of failed SBT, but this treatment strategy has not yet been studied systematically. Since 2011 we have decided to perform SBT with a Solitaire stent (Covidien/ev3, Irvine, California, USA) as a ﬁrst-line revascularization approach in all acute stroke interventions based on our preliminary experience, which showed better revascularization rates in patients receiving SBT than those receiving MAT with a Penumbra reperfusion catheter (Penumbra, Alameda, California, USA). MAT was attempted as a rescue approach if SBT failed. In addition, we thought that the clot may be kept intact for subsequent mechanical revascularization approaches when SBT failed, whereas MAT may break the clot into smaller pieces which makes it more difﬁcult to use subsequent approaches such as SBT following failure of MAT. The aim of this study was to report clinical outcomes of MAT with a Penumbra reperfusion catheter in patients with acute stroke refractory to SBT with a Solitaire stent.
MATERIALS AND METHODS Patients From January 2011 to May 2013, 30 patients with acute ischemic stroke caused by intracranial large artery occlusion were treated with MAT using a Penumbra reperfusion catheter as second-line endovascular therapy after failure of the SBT. This retrospective study analyzed clinical and angiographic data from these 30 patients. During the same period, 163 consecutive patients were treated with SBT using the Solitaire stent as ﬁrst-line endovascular therapy. Upon admission, neurological assessments were performed by a stroke neurologist based on the National Institutes of Health Stroke Scale (NIHSS). All patients underwent a non-enhanced cranial CT scan and multimodal MRI before endovascular treatment. The inclusion criteria for endovascular therapy were: baseline NIHSS score ≥4; no intracerebral hemorrhage detected on the cranial CT or MRI; major arterial occlusion detected with MR
Kim SK, et al. J NeuroIntervent Surg 2015;7:473–477. doi:10.1136/neurintsurg-2014-011203
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Ischemic stroke angiography and catheter angiography; a target mismatch pattern on multimodal MRI based on visual estimation (time to peak map of perfusion imaging showing a lesion volume ≥30% larger than that detected with diffusion-weighted imaging (DWI)) for an anterior circulation stroke; infarct volume on the DWI or non-enhanced CT less than one-third of the middle cerebral artery (MCA) territory for anterior circulation stroke; and no bilateral diffuse pontine ischemia on the DWI for posterior circulation stroke. Eligible patients who met the standard National Institute of Neurological Disorders and Stroke (NINDS) criteria for intravenous recombinant tissue plasminogen activator (rtPA) were initially treated with 0.9 mg/kg intravenous rtPA. Subsequent endovascular therapy was considered within 1 h of intravenous rtPA for patients with no neurological improvement, which was deﬁned as an unchanged NIHSS score from baseline or a worsening neurological deﬁcit.
Endovascular treatment All endovascular therapy was performed by one interventional neuroradiologist with 11 years of experience in neurovascular intervention. Cerebral angiography and endovascular therapy were performed under conscious sedation. In cases of agitation, an intravenous bolus of midazolam was given and repeated if necessary. The details of the technique for SBT with a Solitaire stent have been described previously.10 Refractory occlusion was deﬁned by a lack of successful revascularization (deﬁned as Thrombolysis In Cerebral Infarction (TICI) ≥2b) after ﬁve retrieval attempts. When the refractory occlusion occurred, additional MAT was performed with a Penumbra reperfusion catheter. The details of the technique for MAT with a Penumbra reperfusion catheter have been described previously.5 A direct manual aspiration technique with a 50 mL syringe without a separator or vacuum pump was used in all patients. We used the 054 Penumbra aspiration catheter for occlusions in the distal intracranial internal carotid artery (ICA) or basilar artery or proximal M1 segment of the MCA, and the 041 catheter for occlusions in the distal M1 or M2 segment of the MCA or MCA bifurcation. When the additional MAT with a Penumbra reperfusion catheter was unsuccessful, low-dose intra-arterial urokinase infusion and clot disruption with a micro-guidewire was performed. When the patient had a tandem occlusion at the proximal cervical portion of the ICA, carotid angioplasty and stenting were performed prior to intracranial mechanical thrombectomy. If an underlying atherosclerotic stenosis was revealed during the procedure, balloon angioplasty with or without stenting was performed after mechanical thrombectomy. All patients underwent non-enhanced CT scans immediately after and 24 h after endovascular therapy. The start of endovascular therapy was deﬁned as the moment the needle punctured the common femoral artery. Revascularization status was assessed on the ﬁnal angiogram and classiﬁed according to the TICI scale.11 Successful revascularization was deﬁned as TICI grade 2b or 3. Angiographic images were assessed by two experienced neuroradiologists who were blinded to the procedure and decisions were made by consensus.
Outcome measures For all patients we analyzed the medical records to determine age, sex, vascular risk factors, stroke subtype according to TOAST (Trial of Org 10172 in Acute Stroke Treatment) classiﬁcation, baseline NIHSS score, use of intravenous rtPA, time to endovascular therapy, duration of the procedure, presence or 474
absence of symptomatic intracranial hemorrhage, revascularization status, procedure-related vessel perforation and dissection, NIHSS score at discharge, and clinical outcome. Symptomatic intracranial hemorrhage was deﬁned as any intracranial hemorrhage that caused neurological deterioration (increase of ≥4 points in the NIHSS score or a deterioration of 1 point in the level of consciousness on NIHSS). Major complications were deﬁned as the following events: any arterial perforation or dissection, symptomatic intracranial hemorrhage, periprocedural mortality, or any other complications causing neurological deterioration. Minor complications were deﬁned as any asymptomatic intracranial hemorrhage within 24 h of the procedure or any other complications without causing neurological deterioration. Neurological evaluation was performed immediately after treatment by a stroke neurologist, then again 24 h and 3 months after treatment, when any change occurred in clinical symptoms, and before the patient was discharged. Clinical outcome was assessed by a stroke neurologist using the modiﬁed Rankin scale (mRS) during an outpatient visit 3 months after treatment. If patients were unable to attend the outpatient clinic, outcomes were obtained via telephone interview. A good clinical outcome was deﬁned as an mRS score ≤2.
Statistical analysis Statistical analyses were performed with SPSS software V.20.0 (SPSS, Chicago, Illinois, USA). The relationship between the characteristics and 3-month clinical outcome was determined by bivariate analysis. The χ2 test was used for categorical variables and the Mann–Whitney U test for continuous variables. A p value