Correspondence

Mechanical Extraction of a Basilar-Artery Embolus with the Use of Flow Reversal and a Microbasket

N Engl J Med 2002; 347:769-770September 5, 2002

Article

To the Editor:

Local intraarterial fibrinolysis has improved the outcome for patients with acute vertebrobasilar occlusion. The procedure has increased survival rates to 30 to 45 percent1-3 and resulted in rates of recanalization ranging from 50 to 75 percent.2-5 However, thrombolysis can also lead to intracerebral hematomas, even in the posterior circulation (incidence, 0 to 15 percent),1-5 as well as to systemic hemorrhage.

Mechanical extraction of embolic material offers a potential alternative to fibrinolysis, especially for patients in whom fibrinolysis is contraindicated or in whom it has failed. We and others have tested several extraction devices experimentally. Recently, with the approval of our local ethics committee, we used such a device (Neuronet, Guidant) in a multicenter, phase 1 study — the Neuronet Evaluation in Embolic Stroke Disease study — after testing it in a flow model and in animals. The micro-guide-wire–based device has a self-expanding basket that can be pushed through a standard microcatheter and used to retract an embolus. However, two attempts to retract an embolus in each of two patients with acute occlusion of the distal basilar artery failed, and the patients then underwent fibrinolysis. We subsequently altered the technique for embolus retraction by controlling the blood flow. We could reverse the flow in the vertebrobasilar system by using balloons in the vertebral or subclavian arteries or by using catheters adapted to the diameters of the vertebral arteries.

We report on the use of the combined technique of flow control and embolus retraction in a 17-year-old girl who had a previously unidentified patent foramen ovale and asymptomatic venous thrombosis. She had a progressive brain-stem stroke, with headache and bilateral tinnitus, that began 10 hours before she was enrolled in the study. Five hours after the onset of symptoms, hemihypesthesia developed on the left side, as well as vertigo, double vision, and somnolence. Three hours before angiography, hemiplegia, anarthria, spontaneous nystagmus, and bilateral ptosis developed. Progressive loss of consciousness led to coma two hours before treatment (score on the National Institutes of Health stroke scale, 24; score on the Glasgow coma scale, 4). Computed tomography showed no hypodensity but a hyperdense basilar artery, and cerebral angiography showed that the middle section and top of the basilar artery were occluded by an embolus. The posterior cerebral arteries were supplied collaterally from the circle of Willis. We transiently occluded both vertebral arteries with soft silicone balloons (in the left vertebral artery, next to the coaxial catheter), while retracting the embolus with the extraction device through the coaxial catheter in the left vertebral artery. The clot was retrieved from the basilar artery, but part of the embolus fell through the basket into the intracranial segment of the left vertebral artery. The remaining thrombotic material was removed by suction through the 6-French coaxial catheter, and it was identified as a fresh red thrombus by histologic analysis. Complete recanalization of the vertebrobasilar system was achieved (Figure 1Figure 1Removal of an Embolus from a 17-Year-Old Girl Who Had Progressive Stroke, with Hemiplegia, Anarthria, Bilateral Ptosis, and Loss of Consciousness.). The patient recovered quickly and was asymptomatic one day later (diffusion-weighted magnetic resonance imaging showed only a hyperintense dot of about 2 mm in the pons).

On the basis of preliminary experience with various mechanical devices for the recanalization of intracranial arteries, we recommend using flow control to support the extraction of a thromboembolus (which the proximal flow otherwise keeps in place like a floating cork), as well as to protect distal branches from fragments of the embolus.

Thomas E. Mayer, M.D.
Gerhard F. Hamann, M.D.
Hartmut Brueckmann, M.D.
Ludwig Maximilians University, 81377 Munich, Germany
t.e.mayer@ikra.med.uni-muenchen.de

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Citing Articles (7)

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   Monika Killer, Gunther Ladurner, Alexander B. Kunz, Joerg Kraus. (2010) Current endovascular treatment of acute stroke and future aspects. Drug Discovery Today 15:15-16, 640-647
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   Junji Kashiwagi, Hiro Kiyosue, Yuzo Hori, Mika Okahara, Shuichi Tanoue, Yoshiko Sagara, Toshi Abe, Hiromu Mori. (2010) Endovascular recanalization of acute intracranial vertebrobasilar artery occlusion using local fibrinolysis and additional balloon angioplasty. Neuroradiology 52:5, 361-370
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   Frédéric Clarençon, Raphaël Blanc, Sophie Gallas, Hassan Hosseini, André Gaston. (2009) Thrombectomy for acute basilar artery occlusion by using double Merci retriever devices and bilateral temporary vertebral artery flow reversal. Journal of Neurosurgery 111:1, 53-56
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   R.G. Nogueira, L.H. Schwamm, J.A. Hirsch. (2009) Endovascular Approaches to Acute Stroke, Part 1: Drugs, Devices, and Data. American Journal of Neuroradiology 30:4, 649-661
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   J. Trenkler. (2008) Der akute ischämische Schlaganfall. Der Radiologe 48:5, 457-473
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   Titto T. Idicula, Lenore N. Joseph. (2007) Neurological Complications and Aspects of Basilar Artery Occlusive Disease. The Neurologist 13:6, 363-368
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   Mayer, Thomas, Hamann, Gerhard, Brueckmann, Hartmut, . (2003) Extraction of an Embolus. New England Journal of Medicine 348:6, 557-557
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