Clinical Neurology and Neurosurgery 115 (2013) 2471–2475

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CT perfusion-guided versus time-guided mechanical recanalization in acute ischemic stroke patients夽 Nohra Chalouhi a , George Ghobrial a , Stavropoula Tjoumakaris a , Aaron S. Dumont a , L. Fernando Gonzalez a , Samantha Witte a , Justin Davanzo a , Robert M. Starke a , Ciro Randazzo a , Adam E. Flanders b , David Hasan c , Rohan Chitale a , Robert Rosenwasser a , Pascal Jabbour a,∗ a

Department of Neurosurgery, Thomas Jefferson University and Jefferson Hospital for Neuroscience, Philadelphia, USA Department of Neuroradiology, Thomas Jefferson University Hospital, Philadelphia, USA c Department of Neurosurgery, University of Iowa, Iowa City, USA b

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Article history: Received 21 March 2013 Received in revised form 19 July 2013 Accepted 28 September 2013 Available online 12 October 2013 Keywords: Acute ischemic stroke Computed tomography perfusion Penumbra Selection Timing

a b s t r a c t Objective: Perfusion studies are increasingly used to triage acute stroke patients for endovascular recanalization therapies. We compare the safety and efficacy of CT perfusion (CTP)-guided to time-guided mechanical recanalization in acute ischemic stroke (AIS) patients. Methods: A review was conducted on 132 patients, 94 undergoing CTP-guided and 38 undergoing timeguided (maximum 8 h from symptom onset) mechanical recanalization at our institution. Results: The rate of partial-to-complete recanalization did not differ between the CTP and the non-CTP group (78.7% vs. 81.6%, respectively, p = 0.71). ICH occurred respectively in 18.1% in the CTP group versus 31.6% in the non-CTP group (p = 0.06). The overall in-hospital mortality rate was significantly lower in the CTP group (15.9% vs. 36.8%, p = 0.04). In multivariable analysis, CTP-guided patient selection was an independent negative predictor of in-hospital mortality (OR = 3.2; p = 0.01). CTP-guided patient selection, however, was not a predictor of favorable outcome (Modified Rankin Scale 0–2 or 0–3). Conclusions: CTP-based patient selection was associated with lower ICH and mortality rates. Favorable outcomes, however, did not differ between the 2 groups. These results may suggest a possible benefit in terms of in-hospital mortality with CTP-guided triage of AIS patients for endovascular treatment. © 2013 Elsevier B.V. All rights reserved.

1. Introduction The use of intra-arterial therapies, in general, and mechanical devices, in particular, has emerged as a powerful tool in the management of acute ischemic stroke (AIS) [1–4]. Traditionally, only patients presenting within the 8-h time window were eligible for endovascular mechanical recanalization. With recent advances in imaging techniques, particularly in the field of CT perfusion (CTP), a new approach to patient selection for acute stroke intervention has emerged. This approach takes into account the

夽 All authors have approved the final form of the manuscript and concur with the submission. The work has been approved by the responsible authorities at our institution. ∗ Corresponding author at: Department of Neurological Surgery, Division of Neurovascular Surgery and Endovascular Neurosurgery, Thomas Jefferson University Hospital, 901 Walnut Street 3rd Floor, Philadelphia, PA 19107, USA. Tel.: +1 2159557000; fax: +1 2155037038. E-mail addresses: [email protected], [email protected] (P. Jabbour). 0303-8467/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.clineuro.2013.09.036

extent of salvageable brain tissue or ischemic penumbra to determine a patient’s eligibility for endovascular recanalization [5,6]. Thus, regardless of the time from symptom onset, patients with a large perfusion mismatch and a small necrotic core are selected to undergo endovascular intervention. Conversely, those with a large infarct core and little salvageable tissue have a high risk of hemorrhagic conversion and thus are considered poor candidates for endovascular recanalization. However, the optimal approach for patient selection in the setting of AIS remains the subject of vigorous debate. A recent study by Hassan et al. [7] found no incremental benefit with CTP-guided patient selection as compared to time-guided patient selection, calling into question the utility and potential benefit of such an approach. Others have also questioned the inter-rater reliability of CTP and its capacity in differentiating between salvageable and unsalvageable brain tissue [8–10]. On the other hand, a number of reports have shown that CTP-guided endovascular treatment can efficiently be performed beyond the conventional time window with no additional risk of intracranial hemorrhage (ICH), suggesting that CTP may allow optimal patient selection in this setting [11,12].

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N. Chalouhi et al. / Clinical Neurology and Neurosurgery 115 (2013) 2471–2475

In this study, we compare two different approaches to patient selection for endovascular mechanical recanalization, one based on CTP criteria and the other on time from symptom onset. The two groups are compared with respect to short-term outcomes, namely recanalization rates, ICH rates, in-hospital mortality, and discharge outcomes. 2. Methods The Hospital Institutional Review Board approved the study protocol. We reviewed our prospectively maintained stroke database for all patients who underwent mechanical thrombectomy for AIS in our institution between April 2007 and January 2012. Patients who received chemical thrombolysis or balloon angioplasty/stenting without the use of mechanical devices were systematically excluded from the analysis. A total of 132 patients were identified and constituted our study population. 2.1. Patient selection Until March 2009 at our institution, we performed mechanical thrombectomy on patients with AIS only if they presented within 8 h from symptom onset and had no evidence of ICH, large territorial infarcts, and intraparenchymal tumors on noncontrast CT scan. Since then, we have implemented a new protocol for patient selection based primarily on CTP criteria, regardless of the time from symptom onset. Under this protocol, all patients undergo immediate noncontrast CT, CT angiography, and CTP upon referral to our center. Perfusion scans are performed on the General Electric 32-slice CT scanner. A total of 40 mL of iodinated contrast material is infused in an antecubital vein at a rate of 4 mL/s. Scanning begins 5 s after the start of contrast material infusion. Two 10-mm-thick transverse slices are imaged, one at the level of the basal ganglia and the other at a more caudal location to cover the posterior circulation. The perfusion parameters generated include cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT). CTP maps were qualitatively interpreted by the attending neurointerventionalists. Infarcted tissue, which lacks autoregulation, demonstrates increased MTT and decreased CBV on CTP. Patients with evidence of a large penumbra on CTP (i.e. decreased CBF, preserved CBV, and increased MTT in >30–50% of the affected territory) and NIHSS ≥8 in conjunction with firstorder vessel occlusion on CTA were selected to undergo mechanical thrombectomy. Patients with a large infarct core and a small area at risk (

CT perfusion-guided versus time-guided mechanical recanalization in acute ischemic stroke patients.

Perfusion studies are increasingly used to triage acute stroke patients for endovascular recanalization therapies. We compare the safety and efficacy ...
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