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Successful Treatment of Growing Basilar Artery Dissecting Aneurysm by Pipeline Flow Diversion Embolization Device
Case Report
Successful Treatment of Growing Basilar Artery Dissecting Aneurysm by Pipeline Flow Diversion Embolization Device Dasen Gong, MD,*†‡xk Bernard Yan, FRACP,* Richard Dowling, FRANZCR,{ and Peter Mitchell, FRANZCR, MMed{
We describe a case of successful management of a growing basilar artery dissecting aneurysm by the Pipeline flow diversion embolization device (PED). A 48-year-old woman presented with severe headache, neck pain, and altered consciousness. Computed tomography showed subarachnoid hemorrhage located in basal cisterns, with a pontine infarct shown on magnetic resonance imaging. Digital subtraction angiography showed dissecting aneurysm of the trunk of the basilar artery, with growth over time on repeated imaging. Repeated imaging demonstrated growth in size of the aneurysm. The aneurysm was treated with PED with complete obliteration of the basilar artery aneurysm. Subsequent follow-up demonstrated good clinical recovery. Key Words: Subarachnoid hemorrhage—basilar artery— dissecting aneurysm—pipeline embolization device—flow diverting stent. Ó 2013 by National Stroke Association
Introduction Intracranial dissecting aneurysm of the basilar artery is relatively rare in the adult population. However, subarachnoid hemorrhage secondary to rupture of dissecting aneurysm is associated with high rates of morbidity and mortality because of a propensity to rebleeding.1,2 Surgical treatment of dissecting aneurysm of
From the *Melbourne Brain Centre, University of Melbourne, Royal Melbourne Hospital, Parkville, Victoria, Australia; †Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, PR China; ‡Department of Neurosurgery, Tianjin Neurological Institute, Tianjin, PR China; xKey Laboratory of Post-trauma Neuro-repair and Regeneration in Central Nervous System, Ministry of Education, Tianjin, PR China; kTianjin Key Laboratory of Injuries, Variations and Regeneration of Nervous System, Tianjin, PR China; and {Department of Radiology, Royal Melbourne Hospital, Parkville, Victoria, Australia. Received February 1, 2013; revision received October 6, 2013; accepted November 20, 2013. Address correspondence to Peter Mitchell, Department of Radiology, Royal Melbourne Hospital, Parkville, Victoria 3050, Australia. E-mail: [email protected]. 1052-3057/$ - see front matter Ó 2013 by National Stroke Association http://dx.doi.org/10.1016/j.jstrokecerebrovasdis.2013.11.019
the basilar artery is technically challenging given the fragility of the dissected arterial segment with high risks of intraoperative rupture.3 Stent-assisted coiling is an alterative to surgical treatment, but its use is limited by increased risk of periprocedural aneurysm rupture.1 Pipeline embolization device (PED) is a new-generation stent, which provides a greater metal surface area when fully deployed than open-cell design stents.4 The aim of this design is to provide a larger surface across the neck of the aneurysm to promote aneurysm thrombosis while preserving blood flow into side branch arteries covered by the PED. We report a case of successful embolization of a growing basilar artery fusiform dissecting aneurysm by the PED.
Case Report A 48-year-old woman was admitted with severe headache, neck pain, and altered consciousness. Family history revealed a twin sister who died from a ruptured cerebral aneurysm. Physical examination showed leftsided hemianesthesia and Glasgow Coma Scale score of 14. Computed tomography of brain showed subarachnoid hemorrhage located in basal cisterns (Fig 1, A). Subsequently, the patient developed diplopia, slurred
Journal of Stroke and Cerebrovascular Diseases, Vol. -, No. - (---), 2013: pp 1-4
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Figure 1. (A) Brain computed tomography showed the subarachnoid hemorrhage in the basal cisterns and in the fourth ventricle (arrowhead). (B) T2-weighted image showed ischemic infarct within the pons.
speech, and mild left hemiparesis. Magnetic resonance imaging revealed right pontine infarct (Fig 1, B). Digital subtraction angiography (DSA) showed an aneurysm of the mid-basilar artery, with both fusiform and saccular components, and mild stenosis, consistent with a dissecting aneurysm (Figs 2, 3, A, B). Repeat DSA on day 14 showed marked enlargement of the basilar artery dissecting aneurysm (Fig 3, C, D). On the basis of perceived high risk of rebleeding, it was decided by consensus to offer treatment by PED. Four days before the procedure, the patient was premedicated with 100 mg aspirin and 225 mg clopidogrel loading dose, 75 mg clopidogrel on neurointervention day. Administration of general anesthesia with systemic heparinization
preceded the commencement of the procedure. The 6F short shuttle sheath was positioned in the right subclavian artery. A 150-cm Marksman microcatheter (EV3, Irvine, CA) was positioned beyond the aneurysm into left posterior cerebral artery. The Pipeline embolization device (3.5 3 20 mm; EV3) was deployed across the aneurysm neck from just proximal to the left posterior cerebral artery and superior cerebellar artery. The proximal end of the PED was positioned distal to the right vertebral artery and anterior inferior cerebellar artery, and maximal mesh density was achieved over the midportion of the aneurysm. Repeated angiograms for more than 15 minutes showed gradual progression to complete aneurysm occlusion. Postoperative DSA (1 day and 6 months) showed complete obliteration of the basilar artery dissection, and no embolic complication was detected (Fig 3, E-H). The patients were treated with dual antiplatelet therapy consisting of aspirin (100 mg) and clopidogrel (75 mg) daily for 6 months after the procedure. Clopidogrel treatment was then terminated; aspirin treatment was to be continued for life.
Discussion
Figure 2. Three-dimensional DSA showed the position of the basilar artery dissecting aneurysm (arrow).
Conservative management may be a reasonable option in stable elderly patients.5 However, surgical or endovascular approaches are required when the dissecting aneurysms ruptures or enlarges or if the patient represents with progressive neurologic deficits.6 Surgical treatment of aneurysms includes trapping or clipping. Neither the indications nor the timing of surgical treatment for basilar artery dissecting aneurysm have been established because of the lack of knowledge regarding their natural history. In addition, wall friability of dissecting aneurysms renders surgical management challenging.7 To preserve the parent artery, stent-assisted techniques have been developed to treat dissecting aneurysms.8 Stent-assisted endovascular technique provides the support for coil occlusion of the aneurysm and remodels
PIPELINE EMBOLIZATION DEVICE FOR BASILAR ARTERY DISSECTING ANEURYSM
Figure 3. (A, C, and E) Anteroposterior view; (B, D, and F) Lateral view. (A and B) Initial DSA showed dissecting aneurysm (black arrow) located in the basilar artery trunk. (C and D) Repeat DSA 14 days later showed marked enlargement and the basilar artery dissecting aneurysm. (E and F) Postoperative DSA (1 day) after implantation of PED showed complete obliteration of the basilar artery dissecting aneurysm. (G and H) Postoperative DSA (6 months) after implantation of PED showed complete obliteration of the basilar artery dissecting aneurysm. Abbreviations: PED, Pipeline Flow Diversion Embolization Device.
3
the abnormal vessels, which consequently reduces the blood flow into the dissecting aneurysms and allows for the gradual formation of thrombosis. However, efficacy is limited by the high porosity of currently available stents and the risks and procedural challenges of placing coils into the aneurysmal segment. Clear guidelines for treatment of basilar artery dissecting aneurysms have not yet been formulated. Flow-diverting stents may be an option for reconstruction of the vessel. The Pipeline embolization device is a flexible and selfexpanding construct. The device provides 30% to 35% metal surface area when fully deployed, which can result in remodeling of the dissected segment, produce thrombosis, and prevent recurrence of rebleeding.9 Endothelial growth around the aneurysm neck is induced, aiding the flow division.10,11 Recent other case reports have shown that reconstruction using PED is an attractive alternative in definitive treatment of dissecting VA aneurysms and have demonstrated favorable clinical and angiographic outcomes in the treatment of unruptured and ruptured dissecting VA aneurysms.4,10 Martin et al12 reported that the Pipeline flow-diverting stent may be a viable treatment option for otherwise difficult-to-treat aneurysm morphologies in the context of acute SAH. However, there are other factors that we have to consider. Late thrombosis or thrombus-associated autolysis of flow-diverting device has been reported.13,14 It is necessary for evaluation on a case-by-case basis and a larger research with longer follow-up to ensure the safety of this device. No protocol of antiplatelet medications of dissecting aneurysm for flow-diverting stents during the acute phase of SAH has been defined. Narata et al10 have suggested that antiplatelet therapy should be started as soon as possible and continued at least 6 months. In addition, some stent-assisted coiling studies demonstrate that antiplatelet therapy should be started in the early phase of aneurysm rupture.15,16 However, no consensus has been reached. Tahtinen et al17 found that early use of antiplatelet therapy of ruptured aneurysms treated by using stentassisted coiling resulted in a high mortality of 21%. Four days before the procedure, the patient was premedicated with 100 mg aspirin and 225 mg clopidogrel loading dose. The patient was treated with dual antiplatelet therapy consisting of aspirin (100 mg) and clopidogrel (75 mg) daily for 6 months after the procedure. Clopidogrel treatment was then terminated; aspirin treatment was to be continued for life. The PED was associated with excellent angiographic and clinical results. The parent vessel or perforators from the parent vessel must be considered seriously when angiography reveals inadequate collateral flow.18 Balloon occlusion test can be pivotal in assessing the adequacy of collateral circulation and cortical flow, but it is not always feasible. In our patient, the occlusion test was not performed because the patient had a right
D. GONG ET AL.
4
pontine infarct before the procedure. Only 1 PED was positioned with no evidence of occlusion of any branch of the parent vessel.19
Conclusion We demonstrated a successful case of treatment of a basilar artery dissecting aneurysm with PED. We believe that this may represent a viable alternative to surgical treatment.
References 1. Lee JY, Kwon BJ, Kang HS, et al. Subarachnoid hemorrhage from a dissecting aneurysm of the posterior cerebral artery in a child: rebleeding after stent-assisted coiling followed by stent-within-stent technique. J Korean Neurosurg Soc 2011;49:134-138. 2. Nakahara T, Satoh H, Mizoue T, et al. Dissecting aneurysm of basilar artery presenting with recurrent subarachnoid hemorrhage. Neurosurg Rev 1999;22:155-158. 3. Mizutani T, Aruga T, Kirino T, et al. Recurrent subarachnoid hemorrhage from untreated ruptured vertebrobasilar dissecting aneurysms. Neurosurgery 1995;36:905-911. discussion 912-903. 4. Yeung TW, Lai V, Lau HY, et al. Long-term outcome of endovascular reconstruction with the Pipeline embolization device in the management of unruptured dissecting aneurysms of the intracranial vertebral artery. J Neurosurgery 2012;116:882-887. 5. Sherman P, Oka M, Aldrich E, et al. Isolated posterior cerebral artery dissection: report of three cases. AJNR Am J Neuroradiol 2006;27:648-652. 6. Horie N, Kawahara I, Kitagawa N, et al. Recanalization after endovascular occlusion of a dissecting aneurysm of the posterior cerebral artery—A case report and review of the literature. Clin Neurol Neurosurgery 2008;110:411-415. 7. Sugiu K, Tokunaga K, Watanabe K, et al. Emergent endovascular treatment of ruptured vertebral artery dissecting aneurysms. Neuroradiology 2005;47:158-164. 8. Wakhloo AK, Mandell J, Gounis MJ, et al. Stent-assisted reconstructive endovascular repair of cranial fusiform atherosclerotic and dissecting aneurysms: long-term clinical and angiographic follow-up. Stroke 2008;39:3288-3296.
9. Lylyk P, Miranda C, Ceratto R, et al. Curative endovascular reconstruction of cerebral aneurysms with the pipeline embolization device: the Buenos Aires experience. Neurosurgery 2009;64:632-642. discussion 642-633; quiz N636. 10. Narata AP, Yilmaz H, Schaller K, et al. Flow-diverting stent for ruptured intracranial dissecting aneurysm of vertebral artery. Neurosurgery 2012;70:982-988. discussion 988-989. 11. Fiorella D, Woo HH, Albuquerque FC, et al. Definitive reconstruction of circumferential, fusiform intracranial aneurysms with the pipeline embolization device. Neurosurgery 2008;62:1115-1120. discussion 1120-1111. 12. Martin AR, Cruz JP, Matouk CC, et al. The pipeline flowdiverting stent for exclusion of ruptured intracranial aneurysms with difficult morphologies. Neurosurgery 2012;70:21-28. discussion 28. 13. Fiorella D, Hsu D, Woo HH, et al. Very late thrombosis of a pipeline embolization device construct: case report. Neurosurgery 2010;67:onsE313-onsE314. discussion ons E314. 14. Klisch J, Turk A, Turner R, et al. Very late thrombosis of flow-diverting constructs after the treatment of large fusiform posterior circulation aneurysms. AJNR Am J Neuroradiol 2011;32:627-632. 15. Rasskazoff S, Silvaggio J, Brouwer PA, et al. Endovascular treatment of a ruptured blood blister-like aneurysm with a flow-diverting stent. Interventional Neuroradiol 2010;16:255-258. 16. Kulcsar Z, Wetzel SG, Augsburger L, et al. Effect of flow diversion treatment on very small ruptured aneurysms. Neurosurgery 2010;67:789-793. 17. Tahtinen OI, Vanninen RL, Manninen HI, et al. Widenecked intracranial aneurysms: treatment with stentassisted coil embolization during acute (,72 hours) subarachnoid hemorrhage—experience in 61 consecutive patients. Radiology 2009;253:199-208. 18. Peluso JP, van Rooij WJ, Sluzewski M, et al. Endovascular treatment of symptomatic intradural vertebral dissecting aneurysms. AJNR Am J Neuroradiol 2008; 29:102-106. 19. MacKay CI, Han PP, Albuquerque FC, et al. Recurrence of a vertebral artery dissecting pseudoaneurysm after successful stent-supported coil embolization: case report. Neurosurgery 2003;53:754-759. discussion 760-751.
Successful Treatment of Growing Basilar Artery Dissecting Aneurysm by Pipeline Flow Diversion Embolization Device Dasen Gong, MD,*†‡xk Bernard Yan, FRACP,* Richard Dowling, FRANZCR,{ and Peter Mitchell, FRANZCR, MMed{
We describe a case of successful management of a growing basilar artery dissecting aneurysm by the Pipeline flow diversion embolization device (PED). A 48-year-old woman presented with severe headache, neck pain, and altered consciousness. Computed tomography showed subarachnoid hemorrhage located in basal cisterns, with a pontine infarct shown on magnetic resonance imaging. Digital subtraction angiography showed dissecting aneurysm of the trunk of the basilar artery, with growth over time on repeated imaging. Repeated imaging demonstrated growth in size of the aneurysm. The aneurysm was treated with PED with complete obliteration of the basilar artery aneurysm. Subsequent follow-up demonstrated good clinical recovery. Key Words: Subarachnoid hemorrhage—basilar artery— dissecting aneurysm—pipeline embolization device—flow diverting stent. Ó 2013 by National Stroke Association
Introduction Intracranial dissecting aneurysm of the basilar artery is relatively rare in the adult population. However, subarachnoid hemorrhage secondary to rupture of dissecting aneurysm is associated with high rates of morbidity and mortality because of a propensity to rebleeding.1,2 Surgical treatment of dissecting aneurysm of
From the *Melbourne Brain Centre, University of Melbourne, Royal Melbourne Hospital, Parkville, Victoria, Australia; †Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, PR China; ‡Department of Neurosurgery, Tianjin Neurological Institute, Tianjin, PR China; xKey Laboratory of Post-trauma Neuro-repair and Regeneration in Central Nervous System, Ministry of Education, Tianjin, PR China; kTianjin Key Laboratory of Injuries, Variations and Regeneration of Nervous System, Tianjin, PR China; and {Department of Radiology, Royal Melbourne Hospital, Parkville, Victoria, Australia. Received February 1, 2013; revision received October 6, 2013; accepted November 20, 2013. Address correspondence to Peter Mitchell, Department of Radiology, Royal Melbourne Hospital, Parkville, Victoria 3050, Australia. E-mail: [email protected]. 1052-3057/$ - see front matter Ó 2013 by National Stroke Association http://dx.doi.org/10.1016/j.jstrokecerebrovasdis.2013.11.019
the basilar artery is technically challenging given the fragility of the dissected arterial segment with high risks of intraoperative rupture.3 Stent-assisted coiling is an alterative to surgical treatment, but its use is limited by increased risk of periprocedural aneurysm rupture.1 Pipeline embolization device (PED) is a new-generation stent, which provides a greater metal surface area when fully deployed than open-cell design stents.4 The aim of this design is to provide a larger surface across the neck of the aneurysm to promote aneurysm thrombosis while preserving blood flow into side branch arteries covered by the PED. We report a case of successful embolization of a growing basilar artery fusiform dissecting aneurysm by the PED.
Case Report A 48-year-old woman was admitted with severe headache, neck pain, and altered consciousness. Family history revealed a twin sister who died from a ruptured cerebral aneurysm. Physical examination showed leftsided hemianesthesia and Glasgow Coma Scale score of 14. Computed tomography of brain showed subarachnoid hemorrhage located in basal cisterns (Fig 1, A). Subsequently, the patient developed diplopia, slurred
Journal of Stroke and Cerebrovascular Diseases, Vol. -, No. - (---), 2013: pp 1-4
1
D. GONG ET AL.
2
Figure 1. (A) Brain computed tomography showed the subarachnoid hemorrhage in the basal cisterns and in the fourth ventricle (arrowhead). (B) T2-weighted image showed ischemic infarct within the pons.
speech, and mild left hemiparesis. Magnetic resonance imaging revealed right pontine infarct (Fig 1, B). Digital subtraction angiography (DSA) showed an aneurysm of the mid-basilar artery, with both fusiform and saccular components, and mild stenosis, consistent with a dissecting aneurysm (Figs 2, 3, A, B). Repeat DSA on day 14 showed marked enlargement of the basilar artery dissecting aneurysm (Fig 3, C, D). On the basis of perceived high risk of rebleeding, it was decided by consensus to offer treatment by PED. Four days before the procedure, the patient was premedicated with 100 mg aspirin and 225 mg clopidogrel loading dose, 75 mg clopidogrel on neurointervention day. Administration of general anesthesia with systemic heparinization
preceded the commencement of the procedure. The 6F short shuttle sheath was positioned in the right subclavian artery. A 150-cm Marksman microcatheter (EV3, Irvine, CA) was positioned beyond the aneurysm into left posterior cerebral artery. The Pipeline embolization device (3.5 3 20 mm; EV3) was deployed across the aneurysm neck from just proximal to the left posterior cerebral artery and superior cerebellar artery. The proximal end of the PED was positioned distal to the right vertebral artery and anterior inferior cerebellar artery, and maximal mesh density was achieved over the midportion of the aneurysm. Repeated angiograms for more than 15 minutes showed gradual progression to complete aneurysm occlusion. Postoperative DSA (1 day and 6 months) showed complete obliteration of the basilar artery dissection, and no embolic complication was detected (Fig 3, E-H). The patients were treated with dual antiplatelet therapy consisting of aspirin (100 mg) and clopidogrel (75 mg) daily for 6 months after the procedure. Clopidogrel treatment was then terminated; aspirin treatment was to be continued for life.
Discussion
Figure 2. Three-dimensional DSA showed the position of the basilar artery dissecting aneurysm (arrow).
Conservative management may be a reasonable option in stable elderly patients.5 However, surgical or endovascular approaches are required when the dissecting aneurysms ruptures or enlarges or if the patient represents with progressive neurologic deficits.6 Surgical treatment of aneurysms includes trapping or clipping. Neither the indications nor the timing of surgical treatment for basilar artery dissecting aneurysm have been established because of the lack of knowledge regarding their natural history. In addition, wall friability of dissecting aneurysms renders surgical management challenging.7 To preserve the parent artery, stent-assisted techniques have been developed to treat dissecting aneurysms.8 Stent-assisted endovascular technique provides the support for coil occlusion of the aneurysm and remodels
PIPELINE EMBOLIZATION DEVICE FOR BASILAR ARTERY DISSECTING ANEURYSM
Figure 3. (A, C, and E) Anteroposterior view; (B, D, and F) Lateral view. (A and B) Initial DSA showed dissecting aneurysm (black arrow) located in the basilar artery trunk. (C and D) Repeat DSA 14 days later showed marked enlargement and the basilar artery dissecting aneurysm. (E and F) Postoperative DSA (1 day) after implantation of PED showed complete obliteration of the basilar artery dissecting aneurysm. (G and H) Postoperative DSA (6 months) after implantation of PED showed complete obliteration of the basilar artery dissecting aneurysm. Abbreviations: PED, Pipeline Flow Diversion Embolization Device.
3
the abnormal vessels, which consequently reduces the blood flow into the dissecting aneurysms and allows for the gradual formation of thrombosis. However, efficacy is limited by the high porosity of currently available stents and the risks and procedural challenges of placing coils into the aneurysmal segment. Clear guidelines for treatment of basilar artery dissecting aneurysms have not yet been formulated. Flow-diverting stents may be an option for reconstruction of the vessel. The Pipeline embolization device is a flexible and selfexpanding construct. The device provides 30% to 35% metal surface area when fully deployed, which can result in remodeling of the dissected segment, produce thrombosis, and prevent recurrence of rebleeding.9 Endothelial growth around the aneurysm neck is induced, aiding the flow division.10,11 Recent other case reports have shown that reconstruction using PED is an attractive alternative in definitive treatment of dissecting VA aneurysms and have demonstrated favorable clinical and angiographic outcomes in the treatment of unruptured and ruptured dissecting VA aneurysms.4,10 Martin et al12 reported that the Pipeline flow-diverting stent may be a viable treatment option for otherwise difficult-to-treat aneurysm morphologies in the context of acute SAH. However, there are other factors that we have to consider. Late thrombosis or thrombus-associated autolysis of flow-diverting device has been reported.13,14 It is necessary for evaluation on a case-by-case basis and a larger research with longer follow-up to ensure the safety of this device. No protocol of antiplatelet medications of dissecting aneurysm for flow-diverting stents during the acute phase of SAH has been defined. Narata et al10 have suggested that antiplatelet therapy should be started as soon as possible and continued at least 6 months. In addition, some stent-assisted coiling studies demonstrate that antiplatelet therapy should be started in the early phase of aneurysm rupture.15,16 However, no consensus has been reached. Tahtinen et al17 found that early use of antiplatelet therapy of ruptured aneurysms treated by using stentassisted coiling resulted in a high mortality of 21%. Four days before the procedure, the patient was premedicated with 100 mg aspirin and 225 mg clopidogrel loading dose. The patient was treated with dual antiplatelet therapy consisting of aspirin (100 mg) and clopidogrel (75 mg) daily for 6 months after the procedure. Clopidogrel treatment was then terminated; aspirin treatment was to be continued for life. The PED was associated with excellent angiographic and clinical results. The parent vessel or perforators from the parent vessel must be considered seriously when angiography reveals inadequate collateral flow.18 Balloon occlusion test can be pivotal in assessing the adequacy of collateral circulation and cortical flow, but it is not always feasible. In our patient, the occlusion test was not performed because the patient had a right
D. GONG ET AL.
4
pontine infarct before the procedure. Only 1 PED was positioned with no evidence of occlusion of any branch of the parent vessel.19
Conclusion We demonstrated a successful case of treatment of a basilar artery dissecting aneurysm with PED. We believe that this may represent a viable alternative to surgical treatment.
References 1. Lee JY, Kwon BJ, Kang HS, et al. Subarachnoid hemorrhage from a dissecting aneurysm of the posterior cerebral artery in a child: rebleeding after stent-assisted coiling followed by stent-within-stent technique. J Korean Neurosurg Soc 2011;49:134-138. 2. Nakahara T, Satoh H, Mizoue T, et al. Dissecting aneurysm of basilar artery presenting with recurrent subarachnoid hemorrhage. Neurosurg Rev 1999;22:155-158. 3. Mizutani T, Aruga T, Kirino T, et al. Recurrent subarachnoid hemorrhage from untreated ruptured vertebrobasilar dissecting aneurysms. Neurosurgery 1995;36:905-911. discussion 912-903. 4. Yeung TW, Lai V, Lau HY, et al. Long-term outcome of endovascular reconstruction with the Pipeline embolization device in the management of unruptured dissecting aneurysms of the intracranial vertebral artery. J Neurosurgery 2012;116:882-887. 5. Sherman P, Oka M, Aldrich E, et al. Isolated posterior cerebral artery dissection: report of three cases. AJNR Am J Neuroradiol 2006;27:648-652. 6. Horie N, Kawahara I, Kitagawa N, et al. Recanalization after endovascular occlusion of a dissecting aneurysm of the posterior cerebral artery—A case report and review of the literature. Clin Neurol Neurosurgery 2008;110:411-415. 7. Sugiu K, Tokunaga K, Watanabe K, et al. Emergent endovascular treatment of ruptured vertebral artery dissecting aneurysms. Neuroradiology 2005;47:158-164. 8. Wakhloo AK, Mandell J, Gounis MJ, et al. Stent-assisted reconstructive endovascular repair of cranial fusiform atherosclerotic and dissecting aneurysms: long-term clinical and angiographic follow-up. Stroke 2008;39:3288-3296.
9. Lylyk P, Miranda C, Ceratto R, et al. Curative endovascular reconstruction of cerebral aneurysms with the pipeline embolization device: the Buenos Aires experience. Neurosurgery 2009;64:632-642. discussion 642-633; quiz N636. 10. Narata AP, Yilmaz H, Schaller K, et al. Flow-diverting stent for ruptured intracranial dissecting aneurysm of vertebral artery. Neurosurgery 2012;70:982-988. discussion 988-989. 11. Fiorella D, Woo HH, Albuquerque FC, et al. Definitive reconstruction of circumferential, fusiform intracranial aneurysms with the pipeline embolization device. Neurosurgery 2008;62:1115-1120. discussion 1120-1111. 12. Martin AR, Cruz JP, Matouk CC, et al. The pipeline flowdiverting stent for exclusion of ruptured intracranial aneurysms with difficult morphologies. Neurosurgery 2012;70:21-28. discussion 28. 13. Fiorella D, Hsu D, Woo HH, et al. Very late thrombosis of a pipeline embolization device construct: case report. Neurosurgery 2010;67:onsE313-onsE314. discussion ons E314. 14. Klisch J, Turk A, Turner R, et al. Very late thrombosis of flow-diverting constructs after the treatment of large fusiform posterior circulation aneurysms. AJNR Am J Neuroradiol 2011;32:627-632. 15. Rasskazoff S, Silvaggio J, Brouwer PA, et al. Endovascular treatment of a ruptured blood blister-like aneurysm with a flow-diverting stent. Interventional Neuroradiol 2010;16:255-258. 16. Kulcsar Z, Wetzel SG, Augsburger L, et al. Effect of flow diversion treatment on very small ruptured aneurysms. Neurosurgery 2010;67:789-793. 17. Tahtinen OI, Vanninen RL, Manninen HI, et al. Widenecked intracranial aneurysms: treatment with stentassisted coil embolization during acute (,72 hours) subarachnoid hemorrhage—experience in 61 consecutive patients. Radiology 2009;253:199-208. 18. Peluso JP, van Rooij WJ, Sluzewski M, et al. Endovascular treatment of symptomatic intradural vertebral dissecting aneurysms. AJNR Am J Neuroradiol 2008; 29:102-106. 19. MacKay CI, Han PP, Albuquerque FC, et al. Recurrence of a vertebral artery dissecting pseudoaneurysm after successful stent-supported coil embolization: case report. Neurosurgery 2003;53:754-759. discussion 760-751.