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• RE: RE: The efficacy and safety of endovascular recanalization of occluded large cerebral arteries during the subacute phase of cerebral infarction: a case series report
  Shugui Shi, Kangning Chen
  Published on: 15 December 2017
• RE: The efficacy and safety of endovascular recanalization of occluded large cerebral arteries during the subacute phase of cerebral infarction: a case series report
  Jiangyong Min
  Published on: 15 December 2017

• Published on: 15 December 2017

  RE: RE: The efficacy and safety of endovascular recanalization of occluded large cerebral arteries during the subacute phase of cerebral infarction: a case series report

  • Shugui Shi, Doctor Department of Neurology, Southwest Hospital, Third Military Medical University
  • Other Contributors:
    • Kangning Chen, Doctor

  By Shugui Shi, MD & Kangning Chen, MD.

   

  To the Reader,

   

  We have reviewed your comments on our paper. For your opinion on the issue of penumbra not to be present in subacute phase of stroke, there are literature reporting its presence days after the initial stroke. Penumbra is a dynamic phenomenon without clear demarcation. For example, there is a zone of benign misery perfusion outside of penumbra with its CBF between 15 to 30ml/100g/min (1). This zone may not be viable if perfusion is not re-established. That is to say with a major cerebral arterial occlusion, even with the help of collaterals, brain tissue may die slowly over a period of time. In clinical practice and proven by imaging studies, the side of brain with a large arterial occlusion will significantly atrophy, a process perhaps related to cell apoptosis from chronic hypoxic state (2). Hence, re-opening the occluded artery may or may not help the immediate stroke, but likely help the large ipsilateral brain tissue in a long run. More longitudinal study is certainly needed to examine this issue.

   

  You have questioned our equipment on its ability to detect penumbra. We have had over 10 years of experience in performing MR perfusion with MRI scanner manufactured by Siemens.

   

  All of our patients have received guideline recommended best medical management including dual antiplatelet and statin therapy plus life style modificat...

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  By Shugui Shi, MD & Kangning Chen, MD.

   

  To the Reader,

   

  We have reviewed your comments on our paper. For your opinion on the issue of penumbra not to be present in subacute phase of stroke, there are literature reporting its presence days after the initial stroke. Penumbra is a dynamic phenomenon without clear demarcation. For example, there is a zone of benign misery perfusion outside of penumbra with its CBF between 15 to 30ml/100g/min (1). This zone may not be viable if perfusion is not re-established. That is to say with a major cerebral arterial occlusion, even with the help of collaterals, brain tissue may die slowly over a period of time. In clinical practice and proven by imaging studies, the side of brain with a large arterial occlusion will significantly atrophy, a process perhaps related to cell apoptosis from chronic hypoxic state (2). Hence, re-opening the occluded artery may or may not help the immediate stroke, but likely help the large ipsilateral brain tissue in a long run. More longitudinal study is certainly needed to examine this issue.

   

  You have questioned our equipment on its ability to detect penumbra. We have had over 10 years of experience in performing MR perfusion with MRI scanner manufactured by Siemens.

   

  All of our patients have received guideline recommended best medical management including dual antiplatelet and statin therapy plus life style modification. However, our series was not a clinical trial, the compliance of patient with the treatment plan was not closely tracked.

   

  Reference:

  1. Powers WJ Stroke Misery perfusion in cerebrovascular disease—is it important? Nature Reviews Neurology 2012;8:479-480

   

  2. Thanvi B, Robinson T. Complete occlusion of extracranial internal carotid artery: clinical features, pathophysiology, diagnosis and management Postgrad Med J. 2007; 83(976): 95–99.

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  Conflict of Interest:
  None declared.

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• Published on: 15 December 2017

  RE: The efficacy and safety of endovascular recanalization of occluded large cerebral arteries during the subacute phase of cerebral infarction: a case series report

  • Jiangyong Min, Doctor Mercy Health Neuroscience

  The article by Dr. Chen and his colleagues1 raises an important issue of managing intracranial stenosis or occlusion during the subacute phase of ischemic stroke. The authors concluded that selective percutaneous transluminal angioplasty (PTA) or percutaneous transluminal angioplasty and stenting (PTAS) for intracranial severe stenosis or occlusion is safe and effective in patients with subacute or subacute/chronic stroke. It should be extremely precaution while applying this conclusion into clinical practice. A couple of concerns need to be addressed: (1) there is large body of evidences and publications demonstrated that the ischemic penumbra can exist for only few hours 2. The authors provided the perfusion study in case 1 and commended that there is large area of low perfusion which might be salvageable. However, the authors did not mention which vendor and software have been utilized in the perfusion study. A different vendor and/or software can have significant variability on the result of cerebral perfusion study. I doubt the penumbra (aka, the mismatch on a perfusion study) can last for days in patients with ischemic stroke. (2) American Heart Association/American Stroke Association recommended3 aggressive medical management including dual antiplatelets of aspirin and clopidogrel as well as high-intensity Statin (Class IIB; level of Evidence B) for patients with ischemic stroke caused by 50% to 99% stenosis of a major intracranial artery. Intracranial artery angiop...

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  The article by Dr. Chen and his colleagues1 raises an important issue of managing intracranial stenosis or occlusion during the subacute phase of ischemic stroke. The authors concluded that selective percutaneous transluminal angioplasty (PTA) or percutaneous transluminal angioplasty and stenting (PTAS) for intracranial severe stenosis or occlusion is safe and effective in patients with subacute or subacute/chronic stroke. It should be extremely precaution while applying this conclusion into clinical practice. A couple of concerns need to be addressed: (1) there is large body of evidences and publications demonstrated that the ischemic penumbra can exist for only few hours 2. The authors provided the perfusion study in case 1 and commended that there is large area of low perfusion which might be salvageable. However, the authors did not mention which vendor and software have been utilized in the perfusion study. A different vendor and/or software can have significant variability on the result of cerebral perfusion study. I doubt the penumbra (aka, the mismatch on a perfusion study) can last for days in patients with ischemic stroke. (2) American Heart Association/American Stroke Association recommended3 aggressive medical management including dual antiplatelets of aspirin and clopidogrel as well as high-intensity Statin (Class IIB; level of Evidence B) for patients with ischemic stroke caused by 50% to 99% stenosis of a major intracranial artery. Intracranial artery angioplasty or stenting is not recommended and is investigational (Class III; level of Evidence B). The authors mentioned that the patient of case 1 received dual antiplatelet therapy of aspirin and clopidogrel. However, I cannot tell after reading the article whether the rest of patients in this case series received aggressive medical management. The purpose of medical treatment in patients with acute stroke is to save the ischemic tissue/penumbra. No doubt we can recanalize an occluded intracranial artery to restore normal flow with reaching TICI score 3 after an endovascular procedure, however, no convince rationale for pursuing interventional procedure if there is no or less than 20% mismatch on a perfusion study during the subacute phase of ischemic cerebral infarct without tried aggressive medical therapy. We pursue saving the tissue at risk not the vessel.

  1. Chen K, Hou X, Zhou Z, et al. The efficacy and safety of endovascular recanalization of occluded large cerebral arteries during the subacute phase of cerebral infarction: a case series report. Stroke and Vasc Neurol 2017 0:e000086. doi:10.1136/svn-2017-000086.
  2. Hakim AM. Ischemic penumbra: the therapeutic window. Neurology 1998; 51(Suppl 3): S44-S46
  3. Kernan WN, Ovbiagele B, Black HR, et al. Guidelines for the Prevention of Stroke in Patients With Stroke and Transient Ischemic Attack A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association The American Academy of Neurology affirms the value of this guideline as an educational tool for neurologists. Endorsed by the American Association of Neurological Surgeons and Congress of Neurological Surgeons. Stroke. Stroke 2014;45(7):2160-2236

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  Conflict of Interest:
  None declared.

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