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Delayed enhancing lesions after coil embolization of aneurysms: clinical experience and benchtop analyses
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  • Published on:
    Re:Comment on “Delayed enhancing lesions after coil embolization of aneurysms: clinical experience and benchtop analyses”
    • Se Won Oh, Radiologist Department of Radiology, Soonchunhyang University College of Medicine, Cheonan, Korea
    • Other Contributors:
      • Dong Joon Kim, Radiologist, Neurointerventionist

    We would like to thank Dr. Shotar and colleagues for their interest in our article. As highlighted by Dr. Shotar, delayed enhancing lesions (DEL) after coil embolization of aneurysm are suspected as a result of foreign body reaction 1-5. We agree with their opinion that the catheter coating of the inner wall of guiding catheter and/or the outer wall of microcatheter may be the source of foreign body. However, according to our experiences and analysis, it is our opinion that the coating material of the inner wall of microcatheter may also be the source.
    Dr Shotar suggests that the distribution of the MR lesions in the territory of the parent artery (i.e.: ICA) in our series suggests the guiding catheter as the culprit. However, in all our cases 6, the aneurysms were located at the distal ICA (Ophthalmic artery, IC-anterior choroidal artery, superior hypophyseal artery). Thus, we believe that the distribution of the DELs on MR is not in conflict with our claim that the inner wall of the microcatheter is the source. Foreign body fragments from the microcatheter probably migrated into the aneurysmal sac during multiple coil introduction attempts under unusual friction and were swept downstream. Our benchtop analyses also support this finding.
    Regarding Dr Shotar’s suggestion that "the patient treated with the microcatheter that showed coating fragments at the location of the friction on bench tests did not have DELs", this microcatheter was withdrawn imme...

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    Conflict of Interest:
    None declared.
  • Published on:
    Comment on “Delayed enhancing lesions after coil embolization of aneurysms: clinical experience and benchtop analyses”
    • Eimad Shotar, Interventional Neuroradiologist Department of Interventional Neuroradiology Pitié-Salpêtrière Hospital. APHP. Paris VI University. Paris. FRANCE.
    • Other Contributors:
      • Nader-Antoine Sourour, Interventional Neuroradiologist
      • Frédéric Clarençon, Interventional Neuroradiologist

    We read with interest the article entitled: “Delayed enhancing lesions after coil embolization of aneurysms: clinical experience and benchtop analyses” by Oh et al [1]. This interesting case series deals with a recently described complication of intracranial endovascular procedures [2–8]: delayed enhancing lesions (DELs), also known as NICE (non-ischemic cerebral enhancing) lesions [8]. This rare complication consists in delayed appearance of cortical leptomeningeal enhancement associated with vasogenic subcortical edema [8]. The authors describe 3 more cases, in addition to the 19 previously reported [8]. We congratulate the authors for their efforts to understand the mechanism of this rare complication by performing benchtop tests.
    Numerous hypotheses have been proposed to explain this complication.
    First, an allergic reaction to nickel has been suggested [4,7]. In a series we recently published in Neuroradiology [8], we did not find any allergic reaction to the devices used for the embolization of the patients who presented NICE lesions. The fact that, in the series of Oh et al [1], none of the three patients had an allergic background, seems to confirm the absence of any relationship between these lesions and allergy.
    The second hypothesis is a reaction to foreign bodies (catheter coating) released during the embolization. We do believe that, according to our experience [8] and to the data of the literature [2,3,5,6], these lesions are more likely to...

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    Conflict of Interest:
    None declared.