Case Report Successful endovascular recanalization of a partially occluded basilar artery fenestration Interventional Neuroradiology 0(00) 1–3 ! The Author(s) 2018 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/1591019918793340 journals.sagepub.com/home/ine Thomas Raphael Meinel1 , Frauke Pult2, Jan Gralla2, Marcel Arnold1, Claudio Bassetti1 and Simon Jung1 Abstract A 76-year-old man with a history of arterial hypertension, obstructive sleep apnea, dyslipidemia, family history of cardiovascular events, prestroke and overweight presented 90 minutes after acute onset of right-sided sensorimotor hemiparesis, hemiataxia and dysarthria (National Institutes of Health Stroke Scale (NIHSS) 9/42). Magnetic resonance imaging (MRI) revealed a pontine ischemia and MR angiography showed a thrombus in the middle to distal portion of the basilar artery. Owing to the location, an occlusion of one lumen of a fenestrated basilar artery was suspected. Fearing the risk of peripheral dislocation, intravenous thrombolysis was withheld after an interdisciplinary discussion and direct endovascular thrombectomy (Solitaire stent retriever) was successfully performed by passing the stent retriever specifically through the affected lumen and between the thrombus and the vascular wall, which would normally be avoided. Angiography after complete reperfusion (Thrombolysis in Cerebral Infarction grade 3) confirmed a fenestration in the middle to distal portion of the basilar artery where the thrombus was initially located (blue and green arrow). Follow-up MRI after 24 hours showed only minimal ischemic damage in the left pontine area, and the patient was discharged home with ambulatory physiotherapy for residual minimal gait disturbance (NIHSS 0). Keywords Basilar artery, endovascular, fenestration, ischemic stroke, thrombectomy Received 4 July 2018; accepted 18 July 2018 Introduction A 76-year-old man with a past medical history of arterial hypertension, obstructive sleep apnea, dyslipidemia, family history of cardiovascular events, prestroke and overweight presented 90 minutes after acute onset of right-sided sensorimotor hemiparesis, hemiataxia and dysarthria (National Institutes of Health Stroke Scale (NIHSS) 9/42). Magnetic resonance imaging (MRI) revealed pontine ischemia and MR angiography showed a thrombus in the middle to distal portion of the basilar artery. Owing to the location, we suspected an occlusion of one lumen of a fenestrated basilar artery. Fearing the risk of scattering the thrombus into peripheral emboli, we withheld intravenous thrombolysis after an interdisciplinary discussion and performed direct endovascular thrombectomy (Solitaire stent retriever). Here, it was important to pass the stent retriever specifically through the affected lumen and between the thrombus and the vascular wall, which would normally have been avoided. Angiography after complete reperfusion (Thrombolysis in Cerebral Infarction grade 3) confirmed a fenestration in the middle to distal portion of the basilar artery where the thrombus was initially located (Figure 1). Follow-up MRI after 24 hours showed residual minimal ischemic damage in the left pontine area (Figure 2), and the patient was discharged home with ambulatory physiotherapy for minimal gait disturbance (NIHSS 0). Because the basilar artery results from a fusion of the primitive longitudinal neural arteries, it is known that incomplete fusion leads to fenestrations in about 0.5%–5% of cases depending on the modality of the workup.1 In the rising age of endovascular therapy for acute ischemic stroke, it is crucial to recognize anatomical variants of cerebral blood supply, differentiate them from changes seen with thrombi2 and account for them in endovascular procedure management because 1 Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland 2 University Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland Corresponding author: Thomas Raphael Meinel, Inselspital Bern, Neurology, Freiburgstrasse, 3010 Bern, Switzerland. Email: thomas.meinel@insel.ch 2 Interventional Neuroradiology 0(00) Figure 1. (a) Digital subtraction angiography showing a thrombus attached to the wall of the middle to distal portion of the basilar artery (red arrow). (b) After complete reperfusion, a fenestration of the basilar artery where the thrombus was initially located (blue arrow) was confirmed. Figure 2. (a) The fenestration was also visible on follow-up magnetic resonance angiography (green arrow). (b) A small left-sided pontine ischemia is seen on follow-up magnetic resonance diffusion-weighted imaging B1000 (red arrow). (c) A small pontine ischemia is seen on follow-up fluid-attenuated inversion recovery imaging sequence (blue arrow). the consequences of basilar artery occlusion may be catastrophic.3 In this case, thorough workup revealed no apparent cause of the ischemic stroke and antecedent medication with acetylsalicylic acid was changed after three months of double-platelet aggregation inhibitor therapy to clopidogrel monotherapy with no recurrence at 20 months’ follow-up. intellectual content; Jan Gralla, critical revision of the manuscript for intellectual content; Marcel Arnold, critical revision of the manuscript for intellectual content; Claudio Bassetti, treating physician stroke unit and critical revision of the manuscript for intellectual content; and Simon Jung, treating physician stroke unit and critical revision of the manuscript for intellectual content. Declaration of conflicting interests Acknowledgments We thank Helly Noemi Hammer, MD (Bern, Switzerland), for proofreading the manuscript. Author contributions are as follows: Thomas Raphael Meinel, treating physician stroke unit and writing of the manuscript; Frauke Pult, treating neuroradiologist, acquisition of images, and critical revision of the manuscript for The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. Funding The authors received no financial support for the research, authorship, and/or publication of this article. Meinel et al. 3 ORCID iD Thomas Raphael Meinel 9273 http://orcid.org/0000-0002-0647- References 1. Sogawa K, Kikuchi Y, O’uchi T, et al. Fenestrations of the basilar artery demonstrated on magnetic resonance angiograms: An analysis of 212 cases. Interv Neuroradiol 2013; 19: 461–465. 2. Palazzo P1, Ruff M, Lyerly MJ, et al. Basilar artery thrombus vs. fenestration: A differential diagnostic challenge in acute ischemic stroke. J Neuroimaging 2014; 24: 607–609. 3. Mattle HP, Arnold M, Lindsberg PJ, et al. Basilar artery occlusion. Lancet Neurol 2011; 10: 1002–1014.