Delayed Ischemic Stroke after Stent-assisted Coil Placement in Cerebral Aneurysm: Characteristics and Optimal Duration of Preventative Dual Antiplatelet Therapy

Published Online:https://doi.org/10.1148/radiol.14140070

Delayed ischemic stroke after stent-assisted coil repair of cerebral aneurysm is caused by embolism from the stent or thrombotic occlusion of the stent-containing vessel after early switch of dual antiplatelet therapy to monotherapy, and thus longer-term dual antiplatelet therapy for more than 9 months and late switch to monotherapy are necessary to prevent delayed ischemic stroke.

Purpose

To evaluate characteristics of delayed ischemic stroke after stent-assisted coil placement in cerebral aneurysms and to determine the optimal duration of dual antiplatelet therapy for its prevention.

Materials and Methods

This retrospective study was approved by the institutional review board, and the requirement to obtain written informed consent was waived. Of 1579 patients with 1661 aneurysms, 395 patients (25.0%) with 403 aneurysms (24.3%) treated with stent-assisted coil placement were included and assigned to groups stratified as early (126 patients [31.9%]; 3 months of coil placement), midterm (160 patients [40.5%]; 6 months), or late (109 patients [27.6%]; ≥9 months), according to the time points of switching dual antiplatelet therapy to monotherapy from coil placement. Cumulative rates of delayed ischemic stroke in each group were calculated by using Kaplan-Meier estimates that were compared with log-rank tests. Risk factors of delayed ischemic stroke were identified by using Cox proportional hazard analysis.

Results

Delayed ischemic stroke occurred in 3.5% of all cases (embolism, 3.0%; thrombotic occlusion, 0.5%) within 2 months following the switch. Late switch yielded no delayed ischemic stroke, unlike early (seven of 126 patients [5.6%]; P = .013) or midterm (seven of 160 patients [4.4%]; P = .028) switch. Incomplete occlusion (hazard ratio, 6.68 [95% confidence interval: 1.490, 29.900]) was identified as a risk factor.

Conclusion

Delayed ischemic stroke after stent-assisted coil placement is caused by embolism from or thrombotic occlusion of stent-containing vessels after switching from dual antiplatelet therapy to monotherapy. The stent-containing vessel with incomplete aneurysm occlusion presents as a long-term thromboembolic source. Therefore, dual antiplatelet therapy for more than 9 months and late switch to monotherapy are recommended for its prevention.

© RSNA, 2014

References

  • 1. Bodily KD, Cloft HJ, Lanzino G, Fiorella DJ, White PM, Kallmes DF. Stent-assisted coiling in acutely ruptured intracranial aneurysms: a qualitative, systematic review of the literature. AJNR Am J Neuroradiol 2011;32(7):1232–1236. Crossref, MedlineGoogle Scholar
  • 2. Mocco J, Fargen KM, Albuquerque FC, et al. Delayed thrombosis or stenosis following enterprise-assisted stent-coiling: is it safe? Midterm results of the interstate collaboration of enterprise stent coiling. Neurosurgery 2011;69(4):908–913; discussion 913–914. Crossref, MedlineGoogle Scholar
  • 3. Oxley TJ, Dowling RJ, Mitchell PJ, Davis S, Yan B. Antiplatelet resistance and thromboembolic complications in neurointerventional procedures. Front Neurol 2011;2:83. Crossref, MedlineGoogle Scholar
  • 4. Lee SJ, Cho YD, Kang HS, Kim JE, Han MH. Coil embolization using the self-expandable closed-cell stent for intracranial saccular aneurysm: a single-center experience of 289 consecutive aneurysms. Clin Radiol 2013;68(3):256–263. Crossref, MedlineGoogle Scholar
  • 5. Rossen JD, Chalouhi N, Wassef SN, et al. Incidence of cerebral ischemic events after discontinuation of clopidogrel in patients with intracranial aneurysms treated with stent-assisted techniques. J Neurosurg 2012;117(5):929–933. Crossref, MedlineGoogle Scholar
  • 6. Roy D, Milot G, Raymond J. Endovascular treatment of unruptured aneurysms. Stroke 2001;32(9):1998–2004. Crossref, MedlineGoogle Scholar
  • 7. Meyers PM, Schumacher HC, Higashida RT, et al. Reporting standards for endovascular repair of saccular intracranial cerebral aneurysms. Stroke 2009;40(5):e366–e379. Crossref, MedlineGoogle Scholar
  • 8. Arsava EM, Ballabio E, Benner T, et al. The Causative Classification of Stroke system: an international reliability and optimization study. Neurology 2010;75(14):1277–1284. Crossref, MedlineGoogle Scholar
  • 9. Ay H, Benner T, Arsava EM, et al. A computerized algorithm for etiologic classification of ischemic stroke: the Causative Classification of Stroke System. Stroke 2007;38(11):2979–2984. Crossref, MedlineGoogle Scholar
  • 10. Ay H, Furie KL, Singhal A, Smith WS, Sorensen AG, Koroshetz WJ. An evidence-based causative classification system for acute ischemic stroke. Ann Neurol 2005;58(5):688–697. Crossref, MedlineGoogle Scholar
  • 11. Fargen KM, Hoh BL, Welch BG, et al. Long-term results of enterprise stent-assisted coiling of cerebral aneurysms. Neurosurgery 2012;71(2):239–244; discussion 244. Crossref, MedlineGoogle Scholar
  • 12. Gentric JC, Biondi A, Piotin M, et al. Safety and efficacy of neuroform for treatment of intracranial aneurysms: a prospective, consecutive, French multicentric study. AJNR Am J Neuroradiol 2013;34(6):1203–1208. Crossref, MedlineGoogle Scholar
  • 13. Pierot L, Wakhloo AK. Endovascular treatment of intracranial aneurysms: current status. Stroke 2013;44(7):2046–2054. Crossref, MedlineGoogle Scholar
  • 14. Brilakis ES, Patel VG, Banerjee S. Medical management after coronary stent implantation: a review. JAMA 2013;310(2):189–198. Crossref, MedlineGoogle Scholar

Article History

Received January 11, 2014; revision requested February 19; revision received March 17; accepted April 3; final version accepted April 7.
Published online: June 11 2014
Published in print: Oct 2014