Quantitation of intracranial aneurysm neck size from diagnostic angiograms based on a biomathematical model

Background: The circle of Willis is a network of arteries allowing blood supply to the brain. Bulging of these arteries leads to formation of intracranial aneurysm (IA). Subarachnoid hemorrhage (SAH) due to IA rupture is among the leading causes of disability in the western world. The formation and rupture of IAs is a complex pathological process not completely understood. In the present study, we have precisely measured aneurysmal wall thickness and its uniformity on histological sections and investigated for associations between IA wall thickness/uniformity and commonly admitted risk factors for IA rupture.Methods: Fifty-five aneurysm domes were obtained at the Geneva University Hospitals during microsurgery after clipping of the IA neck. Samples were embedded in paraffin, sectioned and stained with hematoxylin-eosin to measure IA wall thickness. The mean, minimum, and maximum wall thickness as well as thickness uniformity was measured for each IA. Clinical data related to IA characteristics (ruptured or unruptured, vascular location, maximum dome diameter, neck size, bottleneck factor, aspect and morphology), and patient characteristics [age, smoking, hypertension, sex, ethnicity, previous SAH, positive family history for IA/SAH, presence of multiple IAs and diagnosis of polycystic kidney disease (PKD)] were collected.Results: We found positive correlations between maximum dome diameter or neck size and IA wall thickness and thickness uniformity. PKD patients had thinner IA walls. No associations were found between smoking, hypertension, sex, IA multiplicity, rupture status or vascular location, and IA wall thickness. No correlation was found between patient age and IA wall thickness. The group of IAs with non-uniform wall thickness contained more ruptured IAs, women and patients harboring multiple IAs. Finally, PHASES and ELAPSS scores were positively correlated with higher IA wall heterogeneity.Conclusion: Among our patient and aneurysm characteristics of interest, maximum dome diameter, neck size and PKD were the three factors having the most significant impact on IA wall thickness and thickness uniformity. Moreover, wall thickness heterogeneity was more observed in ruptured IAs, in women and in patients with multiple IAs. Advanced medical imaging allowing in vivo measurement of IA wall thickness would certainly improve personalized management of the disease and patient care.

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Abstract TP87: Comparative Analysis of 3-Dimensional Rotation Angiography versus 3-Dimensional Computed Tomography Angiography for Intracranial Aneurysm Treatment Detection and Planning

Stroke ◽

10.1161/str.44.suppl_1.atp87 ◽

2013 ◽

Vol 44 (suppl_1) ◽

Author(s):

Jonathan Park ◽

Noriko Salamon ◽

Gary Duckwiler ◽

Fernando Vinuela ◽

James Sayer ◽

...

Keyword(s):

Intracranial Aneurysm ◽

Clinical Decision Making ◽

Clinical Decision ◽

Neck Size ◽

3 Dimensional ◽

Imaging Tool ◽

Final Treatment ◽

Agreement Coefficient ◽

Majority Consensus ◽

Management Recommendations

Introduction: 3D Rotational Angiography (3DRA) is the gold standard for intracranial aneurysm (IA) detection, but is invasive and time consuming. While 3DCTA has shown to be sensitive for IA detection, no published studies have compared 3DRA to 3DCTA in guiding clinical management. Our aim was to compare suggested treatment for IA based on 3DRA and 3DCTA vs actual final treatment and outcome. Hypothesis: Management recommendations based on blinded review of 3DRA and 3DCTA for IA do not differ significantly. Methods: Prospective blinded review of contemporaneous 3DRA and 3DCTA was performed for patients with suspected IA. Two interventionalists and two neuroradiologists performed blinded, prospective review of 3DRA or 3DCTA, respectively. IA size, location, and morphology were assessed. After IA characterization, each observer independently recommended optimal therapy (conservative, coil, surgery, combined/other) while blinded to other reviewers’ decisions. Findings were analyzed with Spearman, and agreement coefficient 1 (AC1) inter-rater reliability statistics. Results: 41/52 enrolled patients had IA confirmed by 3DRA (52 IA total). 50/52 (96%) IA were initially identified by 3DCTA (both false negatives seen retrospectively). Average IA sac and neck size measured by 3DRA and 3DCTA correlated closely (p<0.01) and were 9.8 and 5.0 mm vs 9.5 and 4.5 mm, respectively. Treatment recommendations by reviewers for 3DRA vs 3DCTA correlated very strongly (AC1= 0.77), as did reader recommendations within a modality (3DRA, AC1=0.66; 3DCTA, AC1=0.79). For 39/52 (75%) of IA, majority consensus for all readers was reached (3/4 or 4/4 reviewers), which correlated well with final executed treatments (95%). Conclusions: Recommendations for IA treatment based on 3DCTA correlate closely with those based on 3DRA, as well as with actual treatment in a majority of patients. 3DCTA holds promise as a primary imaging tool for IA detection and clinical decision making.

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Study of Conformability of the New Leo Plus Stent to a Curved Vascular Model Using Flat-Panel Detector Computed Tomography (Dynact)

Operative Neurosurgery ◽

10.1227/01.neu.0000336304.26756.21 ◽

2009 ◽

Vol 64 (suppl_1) ◽

pp. ONS130-ONS134 ◽

Cited By ~ 6

Author(s):

Miguel Valdivia y Alvarado ◽

Nilou Ebrahimi ◽

Goetz Benndorf

Keyword(s):

Computed Tomography ◽

Intracranial Aneurysm ◽

Cylindrical Shape ◽

Flat Panel ◽

Flat Detector ◽

Aneurysm Neck ◽

Follow Up Study ◽

Vascular Model ◽

Curved Vessels

Abstract Objective: In a previous study, we assessed the conformability limitations of self-expandable stents to a curved vascular model. The LEO stent (Balt Extrusion, Montmorency, France), one of the current self-expandable models available for intracranial aneurysm stenting, displayed 2 adverse mechanics: flattening of the stent midsection and inward crimping of the proximal and distal ends. We present a follow-up study in which we evaluate the conformability to curved vessels of a second-generation stent, LEO PLUS. Methods: A 3.5- × 25-mm LEO PLUS stent was deployed inside a 3-mm × 10-cm poly-tetrafluoroethylene tube (vascular model) with a simulated 5-mm aneurysm neck at its midsection. The polytetrafluoroethylene tube was then placed in a polystyrene block (styrofoam; Dow Chemical Co., Midland, MI) and bent at different angles ranging from 0 to 150 degrees. For each angle, a rotational radiogram was performed using a C-arm angiographic system with a 30- × 43-cm Csl/amorphous silicon flat detector operated with 23-second rotations, 0.80-degree increments, 1 66 projections, and a 2480 × 1920 matrix (2K matrix). Results: The LEO PLUS stent showed symmetric deployment at all tested degrees of curvature, without flattening or kinking. The stent retained its round cylindrical shape at all curvatures without inward crimping of its proximal and distal ends. Conclusion: The previously documented adverse mechanics of the LEO stent were not observed with the new LEO PLUS stent. This suggests better conformability to curved or tortuous vasculature owing to design improvements.

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Clip-on-wrapping with dura mater to treat intracranial aneurysm neck avulsion: Case reports and review of the literature

Clinical Neurology and Neurosurgery ◽

10.1016/j.clineuro.2013.07.034 ◽

2013 ◽

Vol 115 (10) ◽

pp. 2284-2287 ◽

Cited By ~ 3

Author(s):

Yu-gong Feng ◽

Shi-fang Li ◽

Pei-ning Zhang ◽

Tao Xin ◽

Qing-hai Meng ◽

...

Keyword(s):

Intracranial Aneurysm ◽

Dura Mater ◽

Case Reports ◽

Review Of The Literature ◽

Aneurysm Neck

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Repair of intraoperative aneurysm neck tear utilizing the cotton-clipping technique

Neurosurgical FOCUS ◽

10.3171/2015.v1.focus14556 ◽

2015 ◽

Vol 38 (videosuppl1) ◽

pp. Video14 ◽

Cited By ~ 1

Author(s):

Sam Safavi-Abbasi ◽

Hai Sun ◽

Mark E. Oppenlander ◽

Peter Nakaji ◽

M. Yashar S. Kalani ◽

...

Keyword(s):

Intracranial Aneurysm ◽

Suction Device ◽

Aneurysm Clip ◽

Aneurysm Neck ◽

Link Type ◽

Clipping Technique ◽

Intraoperative Rupture

Intraoperative rupture of an intracranial aneurysm is a potentially devastating but controllable complication. The authors have successfully used the previously described cotton-clip technique to repair tears at the necks of aneurysms.1–4 A tear on the neck of the aneurysm is covered with a piece of cotton and held in place with a suction device. The cotton is then clipped onto the tear with an aneurysm clip, using the cotton as a bolster. This simple, effective method has been useful in repairing a partial avulsion of the neck of an aneurysm.1,3The video can be found here: http://youtu.be/nT86RYVQWpc.

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The Role of Blood Impulse in Cerebral Aneurysm Coil Compaction: Effect of Aneurysm Neck Size

Advances in Bioengineering ◽

10.1115/imece2003-43099 ◽

2003 ◽

Cited By ~ 1

Author(s):

Baruch B. Lieber ◽

Chander Sadasivan ◽

Matthew J. Gounis ◽

Ajay K. Wakhloo

Keyword(s):

Cerebral Aneurysms ◽

Momentum Equation ◽

Parent Vessel ◽

Neck Size ◽

Aneurysm Neck ◽

Hemodynamic Forces ◽

Sigmoid Curve ◽

Detachable Coils ◽

Aneurysm Volume

Endovascular occlusion of cerebral aneurysms with bare platinum detachable coils is now recognized as preferable to surgical clipping (ISUIA Group, 2003, ISAT Group, 2002, Bavinzski et al, 1995, Thornton et al, 2002). Dependent on coil packing density (the ratio of the coil volume deposited in an aneurysm to that of the aneurysm volume), aneurysm location, size and neck width, coil compaction with recanalization of the aneurysm remains in the long-term a major concern. The aneurysm neck size is reported to be the main predictor for aneurysm recanalization (Fernandez-Zubillaga et al, 1994). The forces exerted on the coil mass at the aneurysm neck due to blood pulsatility are larger for wide neck aneurysms as compared to small neck aneurysms (Bavinzski et al, 1995). However, impingement forces have not been evaluated. We evaluated the force impinging on the aneurysm neck in a simplified aneurysm (basilar top) geometry utilizing the impulse-momentum equation and Womersley’s flow. Maximum impingement force as a function of aneurysm neck to parent lumen diameter ratio varies as a sigmoid curve. Analysis of the hemodynamic forces affecting coil compaction in cerebral aneurysms shows that the coil mass at the aneurysm neck may be subjected to cyclic impulse impingement due to redirection of blood momentum. Orientation of the aneurysm neck and the main axis of the aneurysm in relation to the oncoming parent vessel flow may help clinicians predict the risk of coil compaction and the location of subsequent aneurysm recanalization.

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Treatment of broad-based intracranial aneurysms with low profile braided stents: a single center analysis of 101 patients

Journal of NeuroInterventional Surgery ◽

10.1136/neurintsurg-2018-014488 ◽

2019 ◽

Vol 11 (6) ◽

pp. 591-597 ◽

Cited By ~ 3

Author(s):

Tanja Djurdjevic ◽

Victoria Young ◽

Rufus Corkill ◽

Dennis Briley ◽

Wilhelm Küker

Keyword(s):

Intracranial Aneurysms ◽

Guide Wire ◽

Neurological Deficits ◽

Anterior Communicating Artery ◽

Parent Artery ◽

Stent Deployment ◽

Stent Occlusion ◽

Neck Size ◽

Aneurysm Neck ◽

Low Profile

Background and purposeLow profile braided stents have facilitated the endovascular treatment of broad-based intracranial aneurysms.MethodsBetween 2013 and June 2018, we attempted 104 Leo baby stent placements in 101 patients. Locations were the anterior communicating artery (AcomA) (37 aneurysms, 35.6%), middle cerebral artery (MCA) bifurcation (29 aneurysms, 27.9%) and basilar artery (23aneurysms, 22.1%). Mean neck size was 4.9 mm (2.2–8.2). 60 aneurysms were incidental, 31 of 37 recurrent aneurysms had ruptured before.ResultsStent deployment was successful in 89.4% of cases. Common reasons for failure were inability to access the parent artery (n=5) or to deploy the stent across the aneurysm neck (n=4). Two patients had poor outcomes within 24 hours. One patient developed a brain hemorrhage caused by guide wire perforation (MRS 5), the other an early thrombotic stent occlusion (MRS 4). No patient died. Nine (8.7%) patients experienced transient neurological deficits with ischemic lesions on diffusion weighted imaging (DWI). Initially Raymond-Roy class 1 occlusion was achieved in 23 aneurysms (24.7%), class 2 occlusion in 40 (43%), class 3a occlusion in 14 (15.0%), and 3b occlusion in 16 aneurysms (17.2%). Follow-up imaging in 87 patients showed stable or improved occlusion grades in 76%. Six patients required retreatment while the rest were managed conservatively. Four delayed stent occlusions occurred in three patients, with severe morbidity in one patient (MRS 5). There were no aneurysm ruptures or deaths.ConclusionStent assisted treatment of broad-based aneurysms with the Leo baby stent is safe and effective. The frequency of delayed thrombotic complications is low and similar to other stents.

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The classification of intracranial aneurysm neck: a single center research experience

Chinese Neurosurgical Journal ◽

10.1186/s41016-018-0138-3 ◽

2018 ◽

Vol 4 (1) ◽

Author(s):

Cai-Qiang Huang ◽

De-Zhi Kang ◽

Liang-Hong Yu ◽

Shu-Fa Zheng ◽

Pei-Sen Yao ◽

...

Keyword(s):

Intracranial Aneurysm ◽

Research Experience ◽

Single Center ◽

Aneurysm Neck ◽

Center Research

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Acute thrombus formation on phosphorilcholine surface modified flow diverters

Journal of NeuroInterventional Surgery ◽

10.1136/neurintsurg-2017-013175 ◽

2017 ◽

Vol 10 (4) ◽

pp. 406-411 ◽

Cited By ~ 28

Author(s):

Miklos Marosfoi ◽

Frederic Clarencon ◽

Erin T Langan ◽

Robert M King ◽

Olivia W Brooks ◽

...

Keyword(s):

Thrombus Formation ◽

Rabbit Model ◽

Flow Diverter ◽

Side Branch ◽

Clot Formation ◽

Neck Size ◽

Aneurysm Neck ◽

Before And After ◽

Surface Modified ◽

Flow Diverters

PurposeThromboembolic complications remain a limitation of flow diverting stents. We hypothesize that phosphorilcholine surface modified flow diverters (Pipeline Flex with Shield Technology, sPED) would have less acute thrombus formation on the device surface compared with the classic Pipeline Embolization device (cPED).MethodsElastase-induced aneurysms were created in 40 rabbits and randomly assigned to receive cPED or sPED devices with and without dual antiplatelet therapy (DAPT) (four groups, n=10/group). Angioplasty was performed to enhance apposition and create intimal injury for a pro-thrombotic environment. Both before and after angioplasty, the flow diverter was imaged with intravascular optical coherence tomography. The outcome measure was the number of predefined segments along the implant relative to the location of the aneurysm with a minimum of 0 (no clot formation) and maximum of 3 (all segments with thrombus). Clot formation over the device at ostia of branch arteries was assessed as either present or absent.ResultsFollowing angioplasty, the number of flow diverter segments with clots was significantly associated with the flow diverter (p<0.0001), but not with DAPT (p=0.3872) or aneurysm neck size (p=0.8555). The incidence rate for clots with cPED was 1.72 times more than with sPED. The clots on the flow diverter at the location corresponding to side branch ostia was significantly lower with sPED than with cPED (OR 0.180; 95% CI 0.044 to 0.734; p=0.0168), but was not associated with DAPT (p=0.3198).ConclusionIn the rabbit model, phosphorilcholine surface modified flow diverters are associated with less thrombus formation on the surface of the device.

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