Introduction: Coil migration during endovascular treatment of intracranial aneurysms occurs in 2-6% of cases. As endovascular coiling of aneurysms has become increasingly popular and as endovascular technology continues to rapidly evolve, the prevalence of intraprocedural coil migration will invariably rise. Since coil masses are highly thrombogenic, migration out of the aneurysm sac into the parent artery may result in large territory infarcts which subsequently manifest as significant neurological morbidity. Therefore safe and timely retrieval of migrated coils is essential to avoiding poor angiographic and clinical outcomes.

Methods: A 66 year-old female with an unruptured 5x3 mm, wide-necked posterior communicating artery aneurysm was referred for endovascular treatment. During coiling with the dual catheter technique, both initially deployed coils dislodged from the aneurysm sac and migrated distally into the middle cerebral artery.

Results: After failed retrieval with an Alligator device, we used two Trevo devices, in succession, to successfully retrieve the migrated coils. The aneurysm was then occluded with stent-assisted coil embolization. There were no post-procedural angiographic or clinical complications. The patient was subsequently discharged home without neurological deficit.

Conclusions: This case illustrates the first use of the Trevo device for retrieval of migrated coils during endovascular treatment of an intracranial aneurysm. Due to the lack of guidelines defining the standard management of intraprocedural coil migration, current strategies are based on retrospective review of published reports and expert opinion. We present a unique and effective method for endovascular retrieval of displaced coils using a Trevo stentriever device.

Patient Care: Significant intraprocedural coil migration during endovascular aneurysm may result in large, devastating territorial infarcts therefore necessitating rapid and successful retrieval of the errant coil(s). The Trevo device may safely and effectively perform this task and should be considered in carefully selected cases.

Learning Objectives: By the conclusion of this session, participants should be able to 1) Describe the importance of rapidly and successfully significantly migrated coils, 2) Discuss, in small groups the efficacy of the Trevo stentriever device for migrated coil retrieval, and 3) Identify an effective treatment for coil migration during endovascular aneurysm treatment.

References: 1. Molyneux A, Kerr R, Stratton I, et al. International Subarachnoid Aneurysm Trial (ISAT) of neurosurgical clipping versus endovascular coiling in 2143 patients with ruptured intracranial aneurysms: a randomised trial. Lancet. Oct 26 2002;360(9342):1267-1274. 2. Li H, Pan R, Wang H, et al. Clipping versus coiling for ruptured intracranial aneurysms: a systematic review and meta-analysis. Stroke. Jan 2013;44(1):29-37. 3. Qureshi AI, Vazquez G, Tariq N, Suri MF, Lakshminarayan K, Lanzino G. Impact of International Subarachnoid Aneurysm Trial results on treatment of ruptured intracranial aneurysms in the United States. Clinical article. J Neurosurg. Mar 2011;114(3):834-841. 4. Henkes H, Fischer S, Weber W, et al. Endovascular coil occlusion of 1811 intracranial aneurysms: early angiographic and clinical results. Neurosurgery. Feb 2004;54(2):268-280; discussion 280-265. 5. White PM, Lewis SC, Nahser H, Sellar RJ, Goddard T, Gholkar A. HydroCoil Endovascular Aneurysm Occlusion and Packing Study (HELPS trial): procedural safety and operator-assessed efficacy results. AJNR Am J Neuroradiol. Feb 2008;29(2):217-223. 6. Casasco AE, Aymard A, Gobin YP, et al. Selective endovascular treatment of 71 intracranial aneurysms with platinum coils. J Neurosurg. Jul 1993;79(1):3-10. 7. Guglielmi G, Vinuela F, Dion J, Duckwiler G. Electrothrombosis of saccular aneurysms via endovascular approach. Part 2: Preliminary clinical experience. J Neurosurg. Jul 1991;75(1):8-14. 8. Lee CY. Use of wire as a snare for endovascular retrieval of displaced or stretched coils: rescue from a technical complication. Neuroradiology. Jan 2011;53(1):31-35. 9. O'Hare AM, Rogopoulos AM, Stracke PC, Chapot RG. Retrieval of displaced coil using a Solitaire((R)) stent. Clin Neuroradiol. Dec 2010;20(4):251-254. 10. O'Hare A, Brennan P, Thornton J. Retrieval of a Migrated Coil Using an X6 MERCI Device. Interv Neuroradiol. Mar 31 2009;15(1):99-102. 11. Schutz A, Solymosi L, Vince GH, Bendszus M. Proximal stent fixation of fractured coils: technical note. Neuroradiology. Nov 2005;47(11):874-878. 12. Horowitz M, Gupta R, Jovin T. The dual catheter technique for coiling of wide-necked cerebral aneurysms. An under-reported method. Interv Neuroradiol. Jun 30 2005;11(2):155-160. 13. Guglielmi G, Vinuela F, Sepetka I, Macellari V. Electrothrombosis of saccular aneurysms via endovascular approach. Part 1: Electrochemical basis, technique, and experimental results. J Neurosurg. Jul 1991;75(1):1-7. 14. Standard SC, Chavis TD, Wakhloo AK, Ahuja A, Guterman LR, Hopkins LN. Retrieval of a Guglielmi detachable coil after unraveling and fracture: case report and experimental results. Neurosurgery. Nov 1994;35(5):994-998; discussion 999. 15. Watanabe A, Hirano K, Mizukawa K, et al. Retrieval of a migrated detachable coil--case report. Neurol Med Chir (Tokyo). Apr 1995;35(4):247-250. 16. Zoarski GH, Bear HM, Clouston JC, Ragheb J. Endovascular extraction of malpositioned fibered platinum microcoils from the aneurysm sac during endovascular therapy. AJNR Am J Neuroradiol. Apr 1997;18(4):691-695. 17. Prestigiacomo CJ, Fidlow K, Pile-Spellman J. Retrieval of a fractured Guglielmi detachable coil with use of the Goose Neck snare "twist" technique. J Vasc Interv Radiol. Oct 1999;10(9):1243-1247. 18. Raftopoulos C, Goffette P, Billa RF, Mathurin P. Transvascular coil hooking procedure to retrieve an unraveled Guglielmi detachable coil: technical note. Neurosurgery. Apr 2002;50(4):912-914; discussion 914-915. 19. Koseoglu K, Parildar M, Oran I, Memis A. Retrieval of intravascular foreign bodies with goose neck snare. Eur J Radiol. Mar 2004;49(3):281-285. 20. Fiorella D, Albuquerque FC, Deshmukh VR, McDougall CG. Monorail snare technique for the recovery of stretched platinum coils: technical case report. Neurosurgery. Jul 2005;57(1 Suppl):E210; discussion E210. 21. Dinc H, Kuzeyli K, Kosucu P, Sari A, Cekirge S. Retrieval of prolapsed coils during endovascular treatment of cerebral aneurysms. Neuroradiology. Apr 2006;48(4):269-272. 22. Henkes H, Lowens S, Preiss H, Reinartz J, Miloslavski E, Kuhne D. A new device for endovascular coil retrieval from intracranial vessels: alligator retrieval device. AJNR Am J Neuroradiol. Feb 2006;27(2):327-329. 23. Vora N, Thomas A, Germanwala A, Jovin T, Horowitz M. Retrieval of a displaced detachable coil and intracranial stent with an L5 Merci Retriever during endovascular embolization of an intracranial aneurysm. J Neuroimaging. Jan 2008;18(1):81-84. 24. Ding D, Liu KC. Management strategies for intraprocedural coil migration during endovascular treatment of intracranial aneurysms. J Neurointerv Surg. Aug 6 2013. 25. Nogueira RG, Lutsep HL, Gupta R, et al. Trevo versus Merci retrievers for thrombectomy revascularisation of large vessel occlusions in acute ischaemic stroke (TREVO 2): a randomised trial. Lancet. Oct 6 2012;380(9849):1231-1240. 26. Hopf-Jensen S, Hensler HM, Preiss M, Muller-Hulsbeck S. Solitaire(R) stent for endovascular coil retrieval. J Clin Neurosci. Jun 2013;20(6):884-886. 27. Leslie-Mazwi TM, Heddier M, Nordmeyer H, et al. Stent Retriever Use for Retrieval of Displaced Microcoils: A Consecutive Case Series. AJNR Am J Neuroradiol. Jun 13 2013.