Crescent sign on magnetic resonance angiography revealing incomplete stent apposition: correlation with diffusion-weighted changes in stent-mediated coil embolization of aneurysms

2011 ◽  
Vol 115 (3) ◽  
pp. 624-632 ◽  
Author(s):  
Robert S. Heller ◽  
William R. Miele ◽  
Daniel D. Do-Dai ◽  
Adel M. Malek
Keyword(s):  
Coil Embolization ◽  
Diffusion Weighted Imaging ◽  
Intracranial Aneurysms ◽  
Mr Angiography ◽  
Ct Scanning ◽  
Thromboembolic Complications ◽  
Incomplete Stent Apposition ◽  
Crescent Sign ◽  
Diffusion Weighted ◽  
Closed Cell

Object Few data are available on how closely stents appose the luminal vessel wall in stent-mediated coil embolization of intracranial aneurysms and on the effect of incomplete stent apposition on procedural thromboembolic complications. Methods Postprocedural 3-T MR diffusion-weighted imaging and time-of-flight angiography were obtained in 58 patients undergoing stent-mediated coil embolization of aneurysms using the Enterprise closed-cell and Neuroform open-cell self-expanding intracranial microstents. Results A distinctive semilunar signal pattern, identified using 3-T MR angiography, represented flow outside the confines of the stent struts in patients in whom Enterprise but not Neuroform devices were used. This pattern, designated as the crescent sign, was confirmed to correspond to incomplete stent apposition by use of high-resolution angiographic flat-panel CT scanning revealing flow ingress into and egress out of the isolated luminal wedge. The presence of the crescent sign was seen in 18 of 33 Enterprise-treated but in 0 of 25 Neuroform-treated cases, and was more likely in stents delivered in the tortuous internal carotid artery (p = 0.034). The crescent sign was strongly predictive of ipsilateral postprocedural lesions seen on diffusion-weighted imaging in the entire population (OR 18, 95% CI 4.33–74.8; p < 0.0001). In the Enterprise stent subset, ipsilateral lesions were detected on diffusion-weighted imaging in 15 (45%) of 33 cases; the crescent sign was seen in 12 (80%) of 15 patients with ipsilateral lesions on diffusion-weighted imaging, but in only 6 of 18 patients without lesions (OR 8, 95% CI 1.61–39.6; p = 0.006). Conclusions Incomplete stent apposition is detectable on 3-T MR angiography as a crescent sign, and was found to be highly prevalent in Enterprise closed-cell design stents used to assist coil embolization of aneurysms. Incomplete stent apposition was also associated with periprocedural ipsilateral hyperintense lesions on diffusion-weighted imaging. These results identify an association between incomplete stent apposition and thromboembolic complications in stent-mediated coil embolization of intracranial aneurysms.

Incomplete stent apposition in Enterprise stent–mediated coiling of aneurysms: persistence over time and risk of delayed ischemic events

2013 ◽  
Vol 118 (5) ◽  
pp. 1014-1022 ◽  
Author(s):  
Robert Heller ◽  
Daniel R. Calnan ◽  
Michael Lanfranchi ◽  
Neel Madan ◽  
Adel M. Malek
Keyword(s):  
Coil Embolization ◽  
Intracranial Aneurysms ◽  
Magnetic Resonance Images ◽  
Incomplete Stent Apposition ◽  
Multiplanar Reconstructions ◽  
Crescent Sign ◽  
Increased Risk ◽  
History Of ◽  
Ischemic Events

Object Incomplete stent apposition of the closed cell–design Enterprise stent following stent-mediated coil embolization of intracranial aneurysms has been associated with increased risk of periprocedural thromboembolic events. In this study, the authors seek to determine the natural history of incomplete stent apposition and evaluate the clinical implications of the phenomenon. Methods Since January 2009, all patients receiving Enterprise stents in the treatment of intracranial aneurysms at the authors' institution have undergone serial 3-T MRI with incomplete stent apposition identified by the crescent sign on multiplanar reconstructions of MR angiograms. Magnetic resonance images and MR angiograms obtained at 3, 9, and 18 months after stent-assisted coil embolization were analyzed along with admission and follow-up clinical medical records. These records were evaluated for any radiographic and clinical, transient or permanent ischemic neurological events. Results Fifty patients receiving Enterprise stents were eligible for inclusion and analysis in the study. Incomplete stent apposition was identified in postoperative imaging studies in 22 (44%) of 50 patients, with 19 (86%) of 22 crescent signs persisting and 3 (14%) of 22 crescent signs resolving on subsequent serial imaging. Delayed ischemic events occurred in 8 (16%) of 50 cases, and all cases involved patients with incomplete stent apposition. The events were transient ischemic attacks (TIAs) in 5 cases, asymptomatic radiographic strokes in 2 cases, and symptomatic strokes and TIAs in the final case. There were no delayed ischemic events in patients who did not have incomplete stent apposition. Only 1 of the delayed ischemic events (2%) was permanent and symptomatic. The postoperative presence of a crescent sign and persistence of the crescent sign were both significantly associated with delayed ischemic events (p < 0.001 and p = 0.002, respectively). Conclusions Incomplete stent apposition is a temporally persistent phenomenon, which resolves spontaneously in only a small minority of cases and appears to be a risk factor for delayed ischemic events. Although further follow-up is needed, these results suggest that longer duration of antiplatelet therapy and clinical follow-up may be warranted in cases of recognized incomplete stent apposition.

scholarly journals Closed-Cell Stent for Coil Embolization of Intracranial Aneurysms: Clinical and Angiographic Results

2012 ◽  
Vol 33 (9) ◽  
pp. 1651-1656 ◽  
Author(s):  
A.K. Wakhloo ◽  
I. Linfante ◽  
C.F. Silva ◽  
E.A. Samaniego ◽  
G. Dabus ◽  
...  
Keyword(s):  
Coil Embolization ◽  
Intracranial Aneurysms ◽  
Closed Cell

LVIS Jr ‘shelf’ technique: an alternative to Y stent-assisted aneurysm coiling

2016 ◽  
Vol 8 (12) ◽  
pp. 1256-1259 ◽  
Author(s):  
Elizabeth Hai Yen Du ◽  
Jai Jai Shiva Shankar
Keyword(s):  
High Risk ◽  
Coil Embolization ◽  
Intracranial Aneurysms ◽  
Case Series ◽  
Cell Design ◽  
Short Term ◽  
Aneurysm Neck ◽  
Closed Cell ◽  
Double Stent ◽  
Aneurysm Coiling

Wide-necked bifurcation intracranial aneurysms have traditionally not been amenable to coil embolization with the use of a single stent due to the high risk of coil prolapse. Y-configuration double stent-assisted coil embolization (‘Y-stenting’) of this aneurysm type has been shown to have generally good clinical outcomes, although the technique is complex with various challenges described in the literature. The compliant and flexible closed-cell design of braided stents such as the LVIS Jr allows for the creation of a ‘shelf’ across the aneurysm neck sufficient to prevent coil prolapse. We describe this novel ‘shelf’ technique and present a small case series of LVIS Jr stent-assisted wide-necked bifurcation intracranial aneurysm coiling in eight patients. Our small, albeit important, case series demonstrates that the ‘shelf’ technique is feasible and safe with very good short-term clinical and angiographic outcomes, and may obviate the need for Y-stenting.

scholarly journals Magnetic Resonance Imaging of Acute Stroke

1998 ◽  
Vol 18 (6) ◽  
pp. 583-609 ◽  
Author(s):  
Alison E. Baird ◽  
Steven Warach
Keyword(s):  
Ischemic Stroke ◽  
Magnetic Resonance ◽  
Acute Stroke ◽  
Perfusion Imaging ◽  
Diffusion Weighted Imaging ◽  
Mr Angiography ◽  
Great Promise ◽  
Proton Density ◽  
Diffusion Weighted ◽  
Cerebral Ischemic

In the investigation of ischemic stroke, conventional structural magnetic resonance (MR) techniques (e.g., T1-weighted imaging, T2-weighted imaging, and proton density-weighted imaging) are valuable for the assessment of infarct extent and location beyond the first 12 to 24 hours after onset, and can be combined with MR angiography to noninvasively assess the intracranial and extracranial vasculature. However, during the critical first 6 to 12 hours, the probable period of greatest therapeutic opportunity, these methods do not adequately assess the extent and severity of ischemia. Recent developments in functional MR imaging are showing great promise for the detection of developing focal cerebral ischemic lesions within the first hours. These include (1) diffusion-weighted imaging, which provides physiologic information about the self-diffusion of water, thereby detecting one of the first elements in the pathophysiologic cascade leading to ischemic injury; and (2) perfusion imaging. The detection of acute intraparenchymal hemorrhagic stroke by susceptibility weighted MR has also been reported. In combination with MR angiography, these methods may allow the detection of the site, extent, mechanism, and tissue viability of acute stroke lesions in one imaging study. Imaging of cerebral metabolites with MR spectroscopy along with diffusion-weighted imaging and perfusion imaging may also provide new insights into ischemic stroke pathophysiology. In light of these advances in structural and functional MR, their potential uses in the study of the cerebral ischemic pathophysiology and in clinical practice are described, along with their advantages and limitations.

Nonoverlapping Y-Configuration Stenting Technique With Dual Closed-Cell Stents in Wide-Neck Basilar Tip Aneurysms

2011 ◽  
Vol 70 (suppl_2) ◽  
pp. ons244-ons249 ◽  
Author(s):  
Young Dae Cho ◽  
Sun-Won Park ◽  
Jong Young Lee ◽  
Jung Hwa Seo ◽  
Hyun-Seung Kang ◽  
...  
Keyword(s):  
Cerebral Artery ◽  
Coil Embolization ◽  
Intracranial Aneurysms ◽  
Posterior Cerebral Artery ◽  
Good Alternative ◽  
The Other ◽  
Parent Artery ◽  
Closed Cell ◽  
Aneurysmal Neck ◽  
Wide Neck

ABSTRACT BACKGROUND: Stent-assisted coiling is increasingly used to treat wide-neck intracranial aneurysms to protect the lumen of the parent artery from coil protrusion. This technique is insufficient for treating some aneurysms, depending on their configurations. OBJECTIVE: To describe a variant of the Y-configuration stent-assisted coiling technique for the treatment of basilar tip aneurysms with wide necks. METHODS: This technique, called the nonoverlapping Y stenting technique, consists of the deployment of a closed-cell self-expandable stent from the basilar trunk to a posterior cerebral artery and then placement of a second stent from the basilar bifurcation to the other posterior cerebral artery without overlapping the first stent. The proximal flared portion of the second stent was located at the neck of the aneurysm. Coil embolization was performed under dual-stent protection. RESULTS: We successfully filled wide-neck aneurysms with coils under stent protection by forming a bridge across the aneurysmal neck without overlapping 2 closed-cell stents. Six basilar tip aneurysms were successfully treated with this technique. CONCLUSION: The nonoverlapping Y stenting technique is a good alternative to traditional stent-assisted coiling. This technique is particularly suitable for the treatment of broad-neck bifurcation aneurysms.

Rescue mechanical thrombectomy using a retrievable stent for thromboembolic occlusion occurring during coil embolization of ruptured intracranial aneurysms

2016 ◽  
Vol 9 (3) ◽  
pp. 244-249 ◽  
Author(s):  
Jun Hyong Ahn ◽  
Hyo Sub Jun ◽  
Joon Ho Song ◽  
Byung Moon Cho ◽  
Ho Kook Lee ◽  
...  
Keyword(s):  
Coil Embolization ◽  
Intracranial Aneurysms ◽  
Mechanical Thrombectomy ◽  
Thromboembolic Complications ◽  
Parent Vessel ◽  
Safety And Efficacy ◽  
Ruptured Aneurysms ◽  
Hemorrhagic Complications ◽  
Ruptured Intracranial Aneurysms ◽  
Retrievable Stent

ObjectiveTo examine the safety and efficacy of mechanical thrombectomy using a retrievable stent for thromboembolic occlusion occurring during coil embolization of ruptured intracranial aneurysms.MethodsBetween June 2011 and June 2015, 631 consecutive patients with ruptured intracranial aneurysms underwent coil embolization at 6 hospitals. Among 53 patients who had thromboembolic complications, 15 patients harboring 15 aneurysms underwent rescue mechanical thrombectomy with a retrievable stent for the treatment of thromboembolic occlusion during the coiling of ruptured aneurysms. The patients' clinical and radiologic outcomes were retrospectively reviewed.ResultsOf the 15 aneurysms, coiling alone was used for 13 (86.7%), and stent-assisted coiling was performed for 2 (13.3%). Thromboembolic occlusion most frequently occurred distal to the aneurysm (n=10, 66.7%), followed by proximal to the aneurysm (n=3, 20%), and at the coil−parent vessel interface (n=2, 13.3%). All patients underwent mechanical thrombectomy with a retrievable stent, including 5 patients who were initially treated with an IA tirofiban infusion. Complete recanalization (Thrombolysis in Cerebral Infarction (TICI) 3) was obtained in 13 (86.7%) and partial recanalization (TICI 2b) in 2 (13.3%). Two patients who had received IA tirofiban before mechanical thrombectomy had hemorrhagic complications. At 6 months after discharge, 9 patients had a modified Rankin Scale (mRS) score of 1, 3 patients were mRS 2, 1 patient was mRS 3, 1 patient was mRS 4, and 1 patient was mRS 6.ConclusionsRescue mechanical thrombectomy using a retrievable stent can be a useful treatment for thromboembolic occlusion occurring during coil embolization of ruptured intracranial aneurysms.

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