Follow-up of coiled intracranial aneurysms: comparison of 3D time-of-flight MR angiography at 3T and 1.5T in a large prospective series

Evaluation of the shrinkage process of a neck remnant after stent-coil treatment of a cerebral aneurysm using silent magnetic resonance angiography and computational fluid dynamics analysis: illustrative case

BACKGROUND

Silent magnetic resonance angiography (MRA) mitigates metal artifacts, facilitating clear visualization of neck remnants after stent and coil embolization of cerebral aneurysms. This study aims to scrutinize hemodynamics at the neck remnant by employing silent MRA and computational fluid dynamics.

OBSERVATIONS

The authors longitudinally tracked images of a partially thrombosed anterior communicating artery aneurysm's neck remnant, which had been treated with stent-assisted coil embolization, using silent MRA over a decade. Computational fluid dynamics delineated the neck remnant's reduction process, evaluating hemodynamic parameters such as flow rate, wall shear stress magnitude and vector, and streamlines. The neck remnant exhibited diminishing surface area, volume, neck size, dome depth, and aspect ratio. Its reduction correlated with a decline in the flow rate ratio of the remnant dome to the inflow parent artery. Analysis delineated regions within the contracting neck remnant characterized by consistently low average wall shear stress magnitude and variation, accompanied by notable variations in wall shear stress vector directionality.

LESSONS

Evaluation of neck remnants after stent-coil embolization is possible through silent MRA and computational fluid dynamics. Predicting the neck remnant reduction may be achievable through hemodynamic parameter analysis.

Imaging follow-up strategy after endovascular treatment of Intracranial aneurysms: A literature review and guideline recommendations

OBJECTIVE

Endovascular coil embolization is the primary treatment modality for intracranial aneurysms. However, its long-term durability remains of concern, with a considerable proportion of cases requiring aneurysm reopening and retreatment. Therefore, establishing optimal follow-up imaging protocols is necessary to ensure a durable occlusion. This study aimed to develop guidelines for follow-up imaging strategies after endovascular treatment of intracranial aneurysms.

METHODS

A committee comprising members of the Korean Neuroendovascular Society and other relevant societies was formed. A literature review and analyses of the major published guidelines were conducted to gather evidence. A panel of 40 experts convened to achieve a consensus on the recommendations using the modified Delphi method.

RESULTS

The panel members reached the following consensus: 1. Schedule the initial follow-up imaging within 3-6 months of treatment. 2. Noninvasive imaging modalities, such as three-dimensional time-of-flight magnetic resonance angiography (MRA) or contrast-enhanced MRA, are alternatives to digital subtraction angiography (DSA) during the first follow-up. 3. Schedule mid-term follow-up imaging at 1, 2, 4, and 6 years after the initial treatment. 4. If noninvasive imaging reveals unstable changes in the treated aneurysms, DSA should be considered. 5. Consider late-term follow-up imaging every 3-5 years for lifelong monitoring of patients with unstable changes or at high risk of recurrence.

CONCLUSIONS

The guidelines aim to provide physicians with the information to make informed decisions and provide patients with high-quality care. However, owing to a lack of specific recommendations and scientific data, these guidelines are based on expert consensus and should be considered in conjunction with individual patient characteristics and circumstances.

A comparison of treating physician versus independent core lab assessments of post-aneurysm treatment imaging outcomes: an analysis of prospectively collected data from a randomized trial

OBJECTIVE

Aneurysm occlusion has been used as surrogate marker of aneurysm treatment efficacy. Aneurysm occlusion scales are used to evaluate the outcome of endovascular aneurysm treatment and to monitor recurrence. These scales, however, require subjective interpretation of imaging data, which can reduce the utility and reliability of these scales and the validity of clinical studies regarding aneurysm occlusion rates. Use of a core lab with independent blinded reviewers has been implemented to enhance the validity of occlusion rate assessments in clinical trials. The degree of agreement between core labs and treating physicians has not been well studied with prospectively collected data.

METHODS

In this study, the authors analyzed data from the Hydrogel Endovascular Aneurysm Treatment (HEAT) trial to assess the interrater agreement between the treating physician and the blinded core lab. The HEAT trial included 600 patients across 46 sites with intracranial aneurysms treated with coiling. The treating site and the core lab independently reviewed immediate postoperative and follow-up imaging (3-12 and 18-24 months, respectively) using the Raymond-Roy occlusion classification (RROC) scale, Meyer scale, and recanalization survey. A post hoc analysis was performed to calculate interrater reliability using Cohen's kappa. Further analysis was performed to assess whether degree of agreement varied on the basis of various factors, including scale used, timing of imaging, size of the aneurysm, imaging modality, location of the aneurysm, dome-to-neck ratio, and rupture status.

RESULTS

Minimal interrater agreement was noted between the core lab reviewers and the treating physicians for assessing aneurysm occlusion using the RROC grading scale (k = 0.39, 95% CI 0.38-0.40) and Meyer scale (k = 0.23, 95% CI 0.14-0.38). The degree of agreement between groups was slightly better but still weak for assessing recanalization (k = 0.45, 95% CI 0.38-0.52). Factors that significantly improved degree of agreement were scales with fewer variables, greater time to follow-up, imaging modality (digital subtraction angiography), and wide-neck aneurysms.

CONCLUSIONS

Assessment of aneurysm treatment outcome with commonly used aneurysm occlusion scales suffers from risk of poor interrater agreement. This supports the use of independent core labs for validation of outcome data to minimize reporting bias. Use of outcome tools with fewer point categories is likely to provide better interrater reliability. Therefore, the outcome assessment tools are ideal for clinical outcome assessment provided that they are sensitive enough to detect a clinically significant change.

Morphological Factors affecting Coil-Only Embolization of Small Unruptured Aneurysms

Objective When small unruptured aneurysms (SUA) are embolized by coils, manipulation of the microcatheter and coil is limited because of their small size. Previous studies suggested that the morphology of the artery and aneurysm is important. In the present study, we clarified the morphological factors affecting coil-only embolization of SUA.

Patients and Methods We retrospectively identified 17 patients who underwent embolization for unruptured aneurysm with a maximum diameter less than 5 mm. We investigated the following: (1) the relationships among dome/neck ratio (D/N), height/neck ratio (H/N), height/dome ratio (H/D), projection of aneurysm-parent artery, and adverse events, (2) immediate and late occlusion, and (3) number of coils.

Results (1) Adverse events developed in three cases in which the H/D was smaller than 1 (p < 0.02). There was a significant difference in the rate of adverse events by projection of the aneurysm-parent artery (p < 0.03), (2) Occlusion rate: Immediately after coil embolization, 71% (12/17) were neck remnant; however, 88% (15/17) of SUA became complete occlusion in the follow-up term, and (3) 1.5 ± 0.6 coils were used.

Conclusion To achieve successful coil-only embolization in SUAs, it is important to select aneurysms for which the projection of the parent artery is suitable for embolizing and the H/D ratio is larger than 1. In SUAs, occlusion develops naturally after coil embolization.

Aspect Ratio Is Associated with Recanalization after Coiling of Unruptured Intracranial Aneurysms

The rate of recanalization after coil embolization for unruptured intracranial aneurysms (UIAs) is reported to occur around 11.3%-49%. This study aims to investigate the factors that influence the recanalization after coil embolization for UIAs in our institution. We retrospectively investigated 307 UIAs in 296 patients treated at our institution between April 2004 and December 2016. The stent-used cases were excluded. Cerebral angiography and 3D time-of-flight magnetic resonance angiography (TOF MRA) were used for evaluation of the postoperative occlusion status. Volume embolization ratio (VER), aneurysmal size, neck width, and aspect ratio (AR) were compared between the recanalized and non-recanalized groups. The mean follow-up period ranged from 6 to 172 months (mean: 79.0 ± 39.8 months). Recanalization was noted in 78 (25.4%) aneurysms, and 19 (6.2%) aneurysms required retreatment. There was no aneurysmal rupture during the follow-up period. Univariate analysis showed that the aneurysm size (p < 0.001), neck width (p < 0.001), AR (p = 0.003), and VER (p = 0.012) were associated with recanalization. Multivariate logistic regression analysis showed that the AR (p =0.004) and VER (p =0.015) were significant predictors of recanalization. To summarize, a higher AR and a lower VER could lead to recanalization after coil embolization of UIAs. Careful follow-up is required for coiled aneurysms with these features.

Follow-Up Assessment of Intracranial Aneurysms Treated with Endovascular Coiling: Comparison of Compressed Sensing and Parallel Imaging Time-of-Flight Magnetic Resonance Angiography

The aim of our study was to compare compressed sensing (CS) time-of-flight (TOF) magnetic resonance angiography (MRA) with parallel imaging (PI) TOF MRA in the evaluation of patients with intracranial aneurysms treated with coil embolization or stent-assisted coiling. We enrolled 22 patients who underwent follow-up imaging after intracranial aneurysm coil embolization. All patients underwent both PI TOF and CS TOF MRA during the same examination. Image evaluation aimed to compare the performance of CS to PI TOF MRA in determining the degree of aneurysm occlusion, as well as the depiction of parent vessel and vessels adjacent to the aneurysm dome. The reference standard for the evaluation of aneurysm occlusion was PI TOF MRA. The inter-modality agreement between CS and PI TOF MRA in the evaluation of aneurysm occlusion was almost perfect (κ  =  0.98, p  <  0.001) and the overall inter-rater agreement was substantial (κ  =  0.70, p  <  0.001). The visualization of aneurysm parent vessel in CS TOF images compared with PI TOF images was evaluated to be better in 11.4%, equal in 86.4%, and worse in 2.3%. CS TOF MRA, with almost 70% scan time reduction with respect to PI TOF MRA, yields comparable results for assessing the occlusion status of coiled intracranial aneurysms. Short scan times increase patient comfort, reduce the risk of motion artifacts, and increase patient throughput, with a resulting reduction in costs. CS TOF MRA may therefore be a potential replacement for PI TOF MRA as a first-line follow-up examination in patients with intracranial aneurysms treated with coil embolization.

Usefulness of Craniograms in Discriminating Coiled Intracranial Aneurysms Requiring Retreatment

While endovascular coil embolization has become one of the major therapeutic modalities for intracranial aneurysms, long-term imaging follow-up is required because of the higher rate of retreatment compared with surgical clipping. The purpose of this study was to show the usefulness of craniograms to discriminate coiled intracranial aneurysms that required retreatment. Under the study protocol approved by institutional review board, a retrospective review of the medical record was done regarding coil embolization for intracranial aneurysms performed between January 2014 and December 2018. Coil embolization performed as the initial treatment and followed up for more than 1 year without additional treatment, and those performed as retreatment after the initial coil embolization performed at our institution were recruited. Craniograms obtained just after the initial treatment were compared with those obtained just before the additional treatment in the retreated cases and compared with the latest ones in the non-recurrence cases. Correlation between the morphological changes in the coil mass on the craniograms and retreatments was evaluated. During the study period, 288 coil embolization procedures for intracranial aneurysms were performed. From these, 191 treatments that were followed up for more than 1 year without any additional treatments and 30 retreatments were included. Morphological change of the coil mass was observed in 4 of the 191 non-recurrence treatments and 26 of the 30 retreatments, which was significantly correlated with retreatments (p <0.001). Craniogram was a useful modality in following up the coiled intracranial aneurysms to detect those required retreatments.

Imaging for Treated Aneurysms (Including Clipping, Coiling, Stents, Flow Diverters)

Intracranial aneurysms are common in the adult population and carry a risk of rupture leading to catastrophic subarachnoid hemorrhage. Treatment of aneurysms has evolved significantly, with the introduction of new techniques and devices for minimally invasive and endovascular approaches. Follow-up imaging after aneurysm treatment is standard of care to monitor for recurrence or other complications, and the preferred imaging modality and schedule for follow-up are areas of active research. The modality and follow-up schedule should be tailored to treatment technique, aneurysm characteristics, and patient factors.

The sensitivity and specificity of TOF-MRA compared with DSA in the follow-up of treated intracranial aneurysms

BACKGROUND

Time-of-flight magnetic resonance angiography (TOF-MRA) is widely used in detecting intracranial aneurysms (IA), but it is limited and controversial for use during follow-up to assess the outcome of interventional coiling or clipping surgery.

METHODS

To evaluate the specificity and sensitivity of using TOF-MRA as an imaging follow-up for IA with different treatments. A total of 280 patients with 326 treated IA underwent simultaneous TOF-MRA and digital subtraction angiography (DSA) as follow-up imaging on the same day. All images were independently reviewed by two neurosurgeons and two radiologists. The consensus evaluation of intra-arterial DSA as a reference test was used to evaluate the result of aneurysm occlusions. The aneurysmal embolization status was assessed with two ratings involving complete or incomplete occlusions. We calculated the sensitivity, specificity, negative predictive value, and positive predictive value of three-dimensional-TOF-MRA to investigate the diagnostic performance.

RESULTS

Overall sensitivity and specificity of TOF-MRA for diagnosing the remnant were 83.3% and 95.2%, respectively. The sensitivity and specificity of interventional therapy was 90.0% and 94.2%, respectively, while the clipping group showed sensitivity and specificity of 50.0% and 100%, respectively. For additional groups, involving coil only, stent-assisted, and flow diverter, the analysis of interventional therapy showed sensitivities and specificities of 100.0% and 90.1%, 66.7% and 95.1%, and 91.7% and 100%, respectively.

CONCLUSIONS

TOF-MRA can be used as a first-line noninvasive imaging modality during follow-up, especially for the patients treated with a pipeline embolization device and coils only. But it may not be enough for clipped aneurysms.

Application of zero echo time MR angiography in follow-up of intracranial aneurysm remnant and in-stent lumen after embolization: a comparison study with digital subtraction angiography

Background

Intracranial aneurysm with endovascular treatment needs to be followed-up with a proper imaging method.

Purpose

To evaluate the performance of magnetic resonance angiography (MRA) with zero echo time at 1.5-T in assessing the intracranial aneurysm remnant and in-stent lumen as compared with time-of-flight MRA, with digital subtraction angiography as the gold standard.

Material and Methods

A total of 46 patients (17 men; mean age = 56.6±13.7 years) with 54 aneurysms who underwent coil embolization with or without stent were enrolled in this study. The presence of aneurysm remnant and the visualization of in-stent lumen were evaluated. The agreement of remnant identification between MRA with zero echo time and time-of-flight MRA with digital subtraction angiography was evaluated using Cohen’s kappa analysis. The performance of in-stent lumen visualization between MRA with zero echo time and time-of-flight MR angiography was compared with Chi-square test.

Results

Of 54 aneurysms, 27 were found to have remnants by digital subtraction angiography. The kappa value in identification of remnant of aneurysm was 0.852 between MRA with zero echo time and digital subtraction angiography and 0.741 between time-of-flight MRA and digital subtraction angiography. In detecting remnant of aneurysm, the sensitivity, specificity, positive predictive value, and negative predictive value were 96.3%, 88.9%, 89.7%, and 96.0% for MRA with zero echo time and 91.7%, 83.3%, 81.5%, and 92.6% for time-of-flight MRA, respectively. In visualizing in-stent lumen, MRA with zero echo time had better performance than time-of-flight MRA ( P < 0.001).

Conclusion

MR angiography with zero echo time might be a better non-invasive approach in assessing remnant of aneurysms and in-stent lumen as compared with time-of-flight MRA.

MRA versus DSA for the follow-up imaging of intracranial aneurysms treated using endovascular techniques: a meta-analysis

BACKGROUND

Treated aneurysms must be followed over time to ensure durable occlusion, as more than 20% of endovascularly treated aneurysms recur. While digital subtraction angiography (DSA) remains the gold standard, magnetic resonance angiography (MRA) is attractive as a non-invasive follow-up technique. Two different MRA techniques have traditionally been used: time-of-flight (TOF) and contrast-enhanced (CE) MRA. We analysed data from studies comparing MRA techniques with DSA for the follow-up of aneurysms undergoing endovascular treatment. Subgroup analysis of stent-assisted coiling (SAC) and flow diversion (FD) techniques was completed.

METHODS

Comprehensive searches using the Embase, PubMed, and Cochrane databases were performed and updated to November 2018. Pooled sensitivity and specificity were calculated using aneurysm occlusion status as defined by the Raymond-Roy occlusion grading scale.

RESULTS

The literature search yielded 1579 unique titles. Forty-three studies were included. For TOF-MRA, sensitivity and specificity of all aneurysms undergoing endovascular therapy were 88% and 94%, respectively. For CE-MRA, the sensitivity and specificity were 88% and 96%, respectively. For SAC and FD techniques, sensitivity and specificity of TOF-MRA were 86% and 95%, respectively. CE-MRA had sensitivity and specificity of 90% and 92%.

CONCLUSION

MRA is a reliable modality for the follow-up of aneurysms treated using endovascular techniques. While the data are limited, MRA techniques can also be used to reliably follow patients undergoing FD and SAC. However, clinical factors must be used to optimize follow-up regimens for individual patients.

Visualization of Aneurysmal Neck and Dome after Coiling with 3D Multifusion Imaging of Silent MRA and FSE-MR Cisternography

BACKGROUND AND PURPOSE

Our aim was to visualize the precise configuration of the aneurysmal neck and dome with/without remnants combined with a coiled dome after coiling treatment for cerebral aneurysms. We developed 3D multifusion imaging of silent MRA and FSE-MR cisternography.

MATERIALS AND METHODS

We examined 12 patients with 3D multifusion imaging by composing 3D images reconstructed from TOF-MRA, silent MRA, and FSE-MR cisternography. The influence of magnetic susceptibility artifacts caused by metal materials affecting the configuration of the aneurysmal complex with coiling was assessed in a single 3D image.

RESULTS

In all cases, TOF-MRA failed to depict the aneurysmal neck complex precisely due to metal artifacts, whereas silent MRA delineated the neck and parent arteries at the coiled regions without serious metal artifacts. FSE-MR cisternography depicted the shape of the coiled aneurysmal dome and parent artery complex together with the brain parenchyma. With the 3D multifusion images of silent MRA and FSE-MR cisternography, the morphologic status of the coiled neck and parent arteries was clearly visualized with the shape of the dome in a single 3D image.

CONCLUSIONS

Silent MRA is a non-contrast-enhanced form of MRA. It depicts the coiled neck complex without serious metal artifacts. FSE-MR cisternography can delineate the shape of the coiled dome. In this small feasibility study, 3D multifusion imaging of silent MRA and FSE-MR cisternography allowed good visualization of key features of coiled aneurysms. This technique may be useful in the follow-up of coiled aneurysms.

Time-resolved magnetic resonance angiography (TR-MRA) for the evaluation of post coiling aneurysms; A quantitative analysis of the residual aneurysm using full-width at half-maximum (FWHM) value

Magnetic resonance image (MRI) is now widely used for imaging follow-up for post coiling brain aneurysms. However, the accuracy on the estimation of residual aneurysm, which is crucial for the retreatment planning, remains to be controversial. The purpose of this study is to evaluate a new post-processing technique that provides improved estimation of the residual aneurysm after coil embolization. One hundred aneurysms on 93 patients who underwent coil embolization for brain aneurysm were evaluated using the 1.5 Tesla time-resolved magnetic resonance angiography (TR-MRA) one year after the treatment. To minimize the inter-observer variability caused by the window level adjustment, an automatic post processing protocol using the full-width at half-maximum (FWHM) value was utilized. The result was then compared with that from the conventional cerebral angiography. Of the 97 aneurysms that underwent both TR-MRA and DSA, 23 (23.7%) showed residual neck / dome during follow-up. After window level adjustment, the size of the parent artery in the TR-MRA was consistent with that in the DSA. The reconstructed Volume Rendering images provided clear contours of the residual aneurysms and contributed to the understanding the configuration of residual aneurysm. The largest and the smallest diameter of the residual aneurysms was larger in the TR-MRA than in the DSA (8.05 vs. 7.72 mm, p = 0.0004; 4.99 vs. 4.19 mm, p = 0.007 respectively). The sensitivity, specificity, and positive and negative predictive values of TR-MRA compared to DSA were 100%, 97%, 73%, and 100%, respectively. Using the FWHM value to optimize the window level adjustment, the size of the residual component observed in the TR-MRA was larger compared to that in the DSA whereas the size of neck and the parent artery showed consistency between the two modalities. This image processing technique can be used as an effective screening tool for evaluating residual component in post-coiling brain aneurysms.

Mid-term 3T MRA follow-up of intracranial aneurysms treated with the Woven EndoBridge

INTRODUCTION

Angiography is the standard follow-up modality for treated aneurysms with the Woven EndoBridge (WEB), and magnetic resonance angiography (MRA) is useful for extended follow-up. We present the results of WEB-treated aneurysms with angiographic follow-up at three months and at least 18 months' 3T MRA follow-up.

MATERIALS AND METHODS

Included were 52 patients with 53 aneurysms treated with the WEB between February 2015 and July 2016. There were 29 women and 23 men with a mean age of 60 years (median 62, range 23-76). Mean aneurysm size was 6.2 mm (median 6, range 3-16 mm).

RESULTS

3T MRA follow-up was mean 19.6 months (median 18, range 18-36 months). One patient had an aneurysm remnant at three-month angiography that was additionally coiled and with stable complete occlusion at 18 months' 3T MRA follow-up. At three-month follow-up angiography, 44 aneurysms were completely occluded and eight had a neck remnant. At latest 3T MRA, stable complete occlusion was present in 43 aneurysms and stable neck remnant in eight. One posterior cerebral artery (PCA) dissection aneurysm was stable at three and six months but was enlarged and reopened at 18 months, confirmed with angiography. Focal signal loss by the proximal marker of the WEB was apparent in four patients without compromising diagnostic evaluation.

CONCLUSION

WEB-treated aneurysms with adequate occlusion at three-month angiography remained stable during serial 3T MRA follow-up of 18-36 months. One PCA aneurysm reopened during the 6- to 18-month interval. Once the WEB-treated aneurysm is adequately occluded in the short term, later reopening is uncommon.

Impact of the global outflow angle on recanalization after endovascular treatment of middle cerebral artery bifurcation aneurysms

Background and purpose

Intracranial aneurysm recanalization after endovascular treatment (EVT) remains a major problem. The goal of this study was to find new predictive factors of recanalization after EVT of middle cerebral artery (MCA) bifurcation aneurysms.

Methods

96 MCA bifurcationaneurysms, ruptured or unruptured, treated by EVT between Septembre 2009 and December 2014, were retrospectively included. Clinical parameters and aneurysm characteristics were recorded. From the initial three-dimensional DSA, spatial coordinates found on parent and daughter arteries of MCA bifurcations gave four different flow angle values; inflow, outflows 1 and 2, and the global outflow angle (the sum of the two outflow angles). Inter- and intra-observer reproducibilities of three-dimensional angle value measurements were performed.

Results

Recanalization occurred in 25 cases (26%) and retreatment was performed in 11 cases (11%). Only 1 patient (1%) had rebleeding. Univariate analysis established the following as predictive factors of recanalization: high blood pressure (P=0.014), aneurysm height (P<0.001), aneurysm width (P<0.001), neck size (P<0.001), postoperative occlusion class (P=0.040), percentage of packing volume (P<0.001), as well as the two outflow angles (P=0.006 and 0.045), and the global outflow angle (P<0.001). Multivariate analysis revealed two independent risk factors for recanalization: the global outflow angle (OR=1.05; 95% CI 1.02 to 1.08; P<0.002) and aneurysm width (OR=0.67; 95% CI 0.46 to 0.96; P=0.031). A global outflow angle threshold <192° was found to be a risk factor for recanalization (OR=13.75; 95% CI 4.46 to 42.44), with a sensitivity of 80% and specificity of 77%.

Conclusions

This study emphasizes that a new parameter, the global outflow angle, can be predictive of recanalization for MCA bifurcation aneurysms treated by EVT.

CT angiography for one-year follow-up of intracranial aneurysms treated with the WEB device: Utility in evaluating aneurysm occlusion and WEB compression at one year

BACKGROUND AND PURPOSE

The WEB is an innovative flow disruption device for cerebral aneurysm embolization with rapidly expanding indications. Our purpose was to evaluate the diagnostic performance of computed tomography angiography (CTA) at 1-year follow-up of aneurysms treated with the WEB.

MATERIALS AND METHODS

Between April 2014 and May 2016, the study prospectively included patients treated with the WEB at our institution, and followed up within 24hours by CTA and at 1year by CTA, time-of-flight magnetic resonance angiography (TOF MRA) and digital subtraction angiography (DSA). The diagnostic quality of imaging data was assessed based on the confidence index, artifacts, and WEB shape depiction. The imaging diagnostic performance was assessed using 3 criteria at 1year: aneurysm occlusion status and worsening, and WEB shape compression. Interobserver and intermodality agreement was determined by calculating κ values.

RESULTS

The study ultimately included 16 patients (9 women, mean age 53±7.6years). CTA quality confidence was scored as 2/2, artifacts 0.4/2 and WEB shape depiction 1.9/2, superior to TOF MRA for the latter two criteria. Aneurysm occlusion was adequate in 93.7% of patients, with CTA showing excellent interobserver reproducibility and agreement with DSA on a 4-grade scale (κ=1.00), while TOF MRA yielded good reproducibility (κ=0.76) and agreement with DSA (κ=0.69). CTA also identified aneurysm occlusion worsening (43.7%) and WEB compression (81.2%) in excellent agreement with DSA (κ=0.85 and 1.00).

CONCLUSIONS

CTA is a reproducible and reliable technique for the follow-up of aneurysms treated with the WEB device.

Balloon-assisted coil embolization and large stent delivery for cerebral aneurysms with a new generation of dual lumen balloons (Copernic 2L)

Introduction

Dual coaxial lumen balloon microcatheters through which small stents can be delivered have recently been described. We report a series of a new type of dual lumen balloon catheter with a parallel lumen design enabling enhanced inflation and deflation properties through which larger stents may be deployed, including flow diverters (FD).

Methods

All aneurysms that were treated with a Copernic 2L (COP2L) dual lumen balloon catheter at our institution between February 2014 and December 2016 were assessed. Patient demographics, aneurysm characteristics, clinical and angiographic follow-up, as well as adverse events were analyzed.

Results

A total of 18 aneurysms in 16 patients (14 women) were treated with the COP2L. Mean maximal aneurysm diameter was 6.4 mm, mean neck size was 3.3 mm (min 1; max 6.3), and mean aneurysm height/width was 1.1 (min 0.5; max 2.1). The COP2L was used for balloon-remodeled coiling exclusively in 2 aneurysms; coiling and FD stenting in 8; coiling and braided stent delivery in 3; coiling, braided and FD stenting in 1; and FD stenting without coiling in 4 (stenting alone). The rate of Roy–Raymond 1 (complete occlusion) changed from 22% in the immediate postoperative period to 100% at 3 months (mean imaging follow-up 8.2 months). There were three technical complications (3/16, 18.7%), including a perforation and two thromboembolic asymptomatic events that were rapidly controlled with the COP2L. There was no immediate or delayed morbidity or mortality (modified Rankin Scale score 0–1 in 100% of patients).

Conclusion

The COP2L is a new type of dual lumen balloon catheter that may be useful for balloon and/or stent-assisted coiling of cerebral aneurysms. The same device can be used to deliver stents up to 4.5 mm and to optimize stent/wall apposition or serve as a life-saving tool in case of thromboembolic or hemorrhagic events. Long-term efficacy and safety need to be further assessed with larger case-controlled cohorts.

Cerebrovascular Imaging: Which Test is Best?

Optimal diagnosis and characterization of cerebrovascular disease requires selection of the appropriate imaging exam for each clinical situation. In this review, we focus on intracranial arterial disease and discuss the techniques in current clinical use for imaging the blood vessel lumen and blood vessel wall, and for mapping cerebral hemodynamic impairment at the tissue level. We then discuss specific strategies for imaging intracranial aneurysms, arteriovenous malformations, dural arterial venous fistulas, and arterial steno-occlusive disease.

Follow-up assessment of coiled intracranial aneurysms using zTE MRA as compared with TOF MRA: a preliminary image quality study

OBJECTIVES

To prospectively assess coiled intracranial aneurysms using a novel non-contrast enhanced zero echo time (zTE) MR angiography (MRA) method, and compare its image quality with time-of-flight (TOF) MRA, using digital subtraction angiography (DSA) as reference.

METHODS

Twenty-five patients (10 males and 15 females; age 53.96 ± 12.46 years) were enrolled in this monocentric study. MRA sequences were performed 24 h before DSA. Susceptibility artefact intensity and flow signal within the parent artery were carried out using a 4-point scale. Occlusion status was assessed using the 3-grade Montreal scale.

RESULTS

Scores of zTE were higher than TOF for both susceptibility artefact intensity (3.42 ± 0.64, 2.92 ± 0.63, P = 0.01) and flow signal (3.66 ± 0.95, 3.24 ± 1.24, P = 0.01). DSA revealed 17 complete occlusions, five residual neck aneurysms and two residual aneurysms. Inter-observer agreement was excellent (weighted κ: 0.89) for zTE and good (weighted κ: 0.68) for TOF. Intermodality agreement was excellent for zTE (weighted κ: 0.95) and good for TOF (weighted κ: 0.80). Correlations of both MRA sequences with DSA were high (zTE, Spearman's ρ: 0.91; TOF, Spearman's ρ: 0.81).

CONCLUSIONS

zTE MRA showed promising results for follow-up assessment of coiled intracranial aneurysms and was superior to TOF MRA for visualizing the parent artery and evaluating occlusion status.

KEY POINTS

• Various MRA sequences were applied for follow-up assessment of coiled intracranial aneurysms. • zTE MRA was less sensitive to susceptibility artefacts and haemodynamics. • In this monocentric study, zTE MRA was equivalent to DSA. • zTE MRA maybe an alternative to TOF MRA for follow-up assessment.

Contrast-Enhanced and Time-of-Flight MRA at 3T Compared with DSA for the Follow-Up of Intracranial Aneurysms Treated with the WEB Device

BACKGROUND AND PURPOSE

Imaging follow-up at 3T of intracranial aneurysms treated with the WEB Device has not been evaluated yet. Our aim was to assess the diagnostic accuracy of 3D-time-of-flight MRA and contrast-enhanced MRA at 3T against DSA, as the criterion standard, for the follow-up of aneurysms treated with the Woven EndoBridge (WEB) system.

MATERIALS AND METHODS

From June 2011 to December 2014, patients treated with the WEB in our institution, then followed for ≥6 months after treatment by MRA at 3T (3D-TOF-MRA and contrast-enhanced MRA) and DSA within 48 hours were included. Aneurysm occlusion was assessed with a simplified 2-grade scale (adequate occlusion [total occlusion + neck remnant] versus aneurysm remnant). Interobserver and intermodality agreement was evaluated by calculating the linear weighted κ. MRA test characteristics and predictive values were calculated from a 2 × 2 contingency table, by using DSA data as the standard of reference.

RESULTS

Twenty-six patients with 26 WEB-treated aneurysms were included. The interobserver reproducibility was good with DSA (κ = 0.71) and contrast-enhanced-MRA (κ = 0.65) compared with moderate with 3D-TOF-MRA (κ = 0.47). Intermodality agreement with DSA was fair with both contrast-enhanced MRA (κ = 0.36) and 3D-TOF-MRA (κ = 0.36) for the evaluation of total occlusion. For aneurysm remnant detection, the prevalence was low (15%), on the basis of DSA, and both MRA techniques showed low sensitivity (25%), high specificity (100%), very good positive predictive value (100%), and very good negative predictive value (88%).

CONCLUSIONS

Despite acceptable interobserver reproducibility and predictive values, the low sensitivity of contrast-enhanced MRA and 3D-TOF-MRA for aneurysm remnant detection suggests that MRA is a useful screening procedure for WEB-treated aneurysms, but similar to stents and flow diverters, DSA remains the criterion standard for follow-up.

Inter- and Intrarater Agreement on the Outcome of Endovascular Treatment of Aneurysms Using MRA

BACKGROUND AND PURPOSE

Patients treated with coiling are often followed by MR angiography. Our objective was to assess the inter- and intraobserver agreement in diagnosing aneurysm remnants and recurrences by using multimodality imaging, including TOF MRA.

MATERIALS AND METHODS

A portfolio composed of 120 selected images from 56 patients was sent to 15 neuroradiologists from 10 institutions. For each case, raters were asked to classify angiographic results (3 classes) of 2 studies (32 MRA-MRA and 24 DSA-MRA pairs) and to provide a final judgment regarding the presence of a recurrence (no, minor, major). Six raters were asked to independently review the portfolio twice. A second study, restricted to 4 raters having full access to all images, was designed to validate the results of the electronic survey.

RESULTS

The proportion of cases judged to have a major recurrence varied between 16.1% and 71.4% (mean, 35.0% ± 12.7%). There was moderate agreement overall (κ = 0.474 ± 0.009), increasing to nearly substantial (κ = 0.581 ± 0.014) when the judgment was dichotomized (presence or absence of a major recurrence). Agreement on cases followed-up by MRA-MRA was similarly substantial (κ = 0.601 ± 0.018). The intrarater agreement varied between fair (κ = 0.257 ± 0.093) and substantial (κ= 0.699 ± 0.084), improving with a dichotomized judgment concerning MRA-MRA comparisons. Agreement was no better when raters had access to all images.

CONCLUSIONS

There is an important variability in the assessment of angiographic outcomes of endovascular treatments. Agreement on the presence of a major recurrence when comparing 2 MRA studies or the MRA with the last catheter angiographic study can be substantial.

WEB-DL Endovascular Treatment of Wide-Neck Bifurcation Aneurysms: Long-Term Results in a European Series

BACKGROUND AND PURPOSE

Flow disruption with the WEB-DL device has been used safely for the treatment of wide-neck bifurcation aneurysms. The stability of aneurysm occlusion after this treatment was evaluated in the short and midterm, but not in the long term. This retrospective multicenter European study is the continuation of an already published series dealing with short- and midterm anatomic results and analyzes long-term data in patients treated with the WEB-DL.

MATERIALS AND METHODS

Twelve European neurointerventional centers initially participated in the study. In addition to data collected for the initial publication, images obtained at long-term follow-up were collected and independently analyzed by the same experienced interventional neuroradiologist.

RESULTS

Of the initial 45 patients, 26 (20 women and 6 men; 35-73 years of age; mean, 55.2 ± 10.6 years; median, 55.5 years) with 26 aneurysms treated with the WEB-DL device had long-term follow-up (median, 27.4 months). Three of 26 patients (11.5%) were retreated between short- and midterm follow-up, and none, between mid- and long-term follow-up. Long-term aneurysm occlusion in the 19 patients treated with the WEB only and not retreated during follow-up was complete occlusion in 13/19 patients (68.4%), including aneurysms with opacification of the proximal recess in 9/19 patients (47.4%), neck remnant in 3/19 patients (15.8%), and aneurysm remnant in 3/19 patients (15.8%). In all patients (100.0%), aneurysm occlusion was stable between midterm and long-term follow-up.

CONCLUSIONS

The results suggest that WEB treatment of wide-neck bifurcation aneurysms offers long-term stable occlusion.

Detection of aneurysmal subarachnoid hemorrhage 3 months after initial bleeding: evaluation of T2* and FLAIR MR sequences at 3 T in comparison with initial non-enhanced CT as a gold standard

OBJECTIVE

To investigate the ability of T2* and fluid-attenuated inversion recovery (FLAIR) MR sequences to detect hemosiderin deposition 3 months after aneurysmal subarachnoid hemorrhage (SAH) in comparison with early non-enhanced CT (NECT) as a gold standard.

MATERIALS AND METHODS

From September 2008 through May 2013, patients with aneurysmal SAH were included if a NECT less than 24 h after the onset of symptoms showed a SAH, and MRI, including T2* and FLAIR sequences, was performed 3 months later. All aneurysms were treated endovascularly. NECT and MR sequences were blindly analyzed for the presence of SAH (NECT) or hemosiderin deposition (MRI). When positive, details of the spatial distribution of SAH or hemosiderin deposits were noted. Sensitivities were calculated for each patient. Sensitivities, specificities, and positive predictive values (PPVs) were calculated for each location.

RESULTS

Forty-nine patients (mean age 52.9 years) were included. Bleeding-related patterns were identified in 43 patients (87.8%) on T2* and 10 patients (20.4%) on FLAIR. T2* was highly predictive of the location of the initial hemorrhage, especially in the Sylvian cisterns (PPVs 95% and 100%) and the anterior interhemispheric fissure (PPV 90%).

CONCLUSIONS

The T2* sequence can detect and localize a previous SAH a few months after aneurysmal bleeding.

Follow-up of intracranial aneurysms treated by a WEB flow disrupter: a comparative study of DSA and contrast-enhanced MR angiography

Objective

To compare contrast-enhanced MR angiography (CE-MRA) and DSA for the follow-up of intracranial aneurysms (IAs) treated with the Woven EndoBridge embolization system DL (WEB DL; Sequent Medical, Aliso Viejo, California, USA).

Materials and methods

We retrospectively identified all patients treated with a WEB DL between November 2010 and February 2013 in 2 hospitals. The IA occlusion was graded on follow-up CE-MRA and DSA by 4 independent readers and by 2 readers reaching a consensus, respectively. Interobserver agreement for MRA and intertechnique agreement was evaluated by calculating linear weighted κ.

Results

Fifteen patients with 16 IAs were included. Mean delay between MRA and DSA was 2 months (range 0–16 months). Interobserver agreement for MRA was substantial to almost perfect (κ=0.686–0.921; mean κ=0.809). Intertechnique agreement was moderate to substantial (κ=0.579–0.724; mean κ=0.669). Only three out of five inadequately occluded IAs were detected by MRA.

Conclusions

CE-MRA is a useful tool for the follow-up of IAs treated with a WEB DL. However, early follow-up with DSA remains mandatory to detect inadequately occluded IAs.

Is visual evaluation of aneurysm coiling a reliable study end point? Systematic review and meta-analysis

BACKGROUND AND PURPOSE

Angiographic occlusion as a surrogate marker of satisfactory aneurysm treatment is commonly used in clinical trials although some pitfalls have to be considered. To investigate the inter-rater reliability of visual rating of aneurysm occlusion as study end point, we performed a systematic review and meta-analysis.

METHODS

Electronic databases (MEDLINE, EMBASE, PubMed, and the Cochrane Library) were searched up to June 2014. Assessment of risk for bias was based on the Quality Appraisal Tool for Studies of Diagnostic Reliability and the Guidelines for Reporting Reliability and Agreement studies. Inter-rater reliability estimates were pooled across studies using meta-analysis, and the influence of several factors (eg, imaging methods, grading scales, and occlusion rate) was tested with meta-regression.

RESULTS

From 1193 titles, 644 abstracts and 87 full-text versions were reviewed. Twenty-six articles met the inclusion criteria and provided 77 reliability estimates. Twenty-one different rating scales were used, and statistical analysis varied. Mean inter-rater agreement of the pooled studies was substantial (κ=0.65; 95% confidence interval, 0.60-0.69). Reliability varied significantly as a function of imaging methods, grading scales, occlusion rates, and their interaction. Observer agreement substantially increased with increasing occlusion rate in digital subtraction angiography but not in MR angiography. Reliability was higher in studies using 2- or 3-value grading scales than in studies with 4-value grading scales.

CONCLUSIONS

There is significant heterogeneity between studies evaluating the reliability of visual evaluation of aneurysm coiling. On the basis of our analysis, we found that the combination of magnetic resonance angiography, 3-value grading scale, and 2 trained raters seems most promising for usage as surrogate study end points.

Rebleeding of a neck remnant in a case of ruptured aneurysm initially treated with coils

The follow-up and indications for retreatment of intracranial aneurysms treated endovascularly are still a matter of debate. We report the case of a patient with a ruptured aneurysm who was treated twice with coils and regularly followed up with MRI/MR angiography which showed a neck remnant that finally rebled.

Rebleeding of a neck remnant in a case of ruptured aneurysm initially treated with coils

The follow-up and indications for retreatment of intracranial aneurysms treated endovascularly are still a matter of debate. We report the case of a patient with a ruptured aneurysm who was treated twice with coils and regularly followed up with MRI/MR angiography which showed a neck remnant that finally rebled.

Optimized angiographic CT using intravenous contrast injection: a noninvasive imaging option for the follow-up of coiled aneurysms?

BACKGROUND AND PURPOSE

Because recanalization of coiled cerebral aneurysms is reported to occur, follow-up imaging is mandatory, ideally noninvasively. Our study aimed to evaluate the accuracy of an optimized angiographic CT by using intravenous contrast material injection in the assessment of coiled cerebral aneurysms, compared with MR angiography and digital subtraction angiography, the criterion standard.

MATERIALS AND METHODS

We included 69 patients with 76 coiled cerebral aneurysms. In each patient, we performed an angiographic CT with intravenous contrast material injection with a dual rotational acquisition, a time-of-flight MR angiography, and a DSA. The angiographic CT with intravenous contrast material injection data was postprocessed by using newly implemented reconstructions modes and a dual-volume technique. An aneurysm occlusion rate was assessed in angiographic CT with intravenous contrast material injection and MRA; remnants were measured and correlated with DSA, respectively.

RESULTS

Twenty-eight remnants were revealed by DSA with a mean size of 3.1 × 3.1 mm. Angiographic CT with intravenous contrast material injection demonstrated a sensitivity of 93% and a specificity of 96% in remnant detection. MRA showed almost identical accuracy (sensitivity of 93%, specificity of 100%). Assessment of remnant size by angiographic CT with intravenous contrast material injection and by MRA revealed a high significant correlation with DSA, respectively (P < .001).

CONCLUSIONS

Optimized angiographic CT with intravenous contrast material injection and MRA demonstrated accuracy comparable with that of DSA in the follow-up of coiled aneurysms, respectively. The assessment of remnant size showed a high correlation with DSA for both techniques. Due to the lack of radiation exposure, MRA seems to be the preferred technique. However, angiographic CT with intravenous contrast material injection can be considered a reliable, noninvasive alternative in patients with MR imaging contraindications or in cases of compromising artifacts due to metal implants (ie, clips).

Detection and characterization of unruptured intracranial aneurysms: Comparison of 3T MRA and DSA

PURPOSE

To compare magnetic resonance angiography (MRA) at 3 Tesla (3T) and digital subtraction angiography (DSA) for the detection and characterization of unruptured intracranial aneurysms (UIA).

MATERIALS AND METHODS

This study has been approved by our local ethical committee. From February to August 2010, 40 consecutive patients with UIA contemporarily underwent MRA at 3T including time-of-flight (TOF-MRA) and contrast enhanced (CE-MRA) techniques and DSA. MR images were independently reviewed by 3 radiologists and DSA images were reviewed by 2 radiologists together. Interobserver and intertechnique agreements were assessed for aneurysm detection and characterization including maximal diameter, neck width and the presence of a bleb or a branch arising from the sac.

RESULTS

DS angiography revealed 56 aneurysms. Mean sensitivity and positive predictive value of MRA were 91.4% and 93.4% respectively. For UIA < 3 mm and those ≥ 3 mm, MRA had a mean sensitivity of 74.1% and 100% respectively. Intertechnique and interobserver agreements were substantial for the measurement of UIA maximal diameter (mean κ, 0.607 and 0.601 respectively) and were moderate and fair for neck width measurement respectively (mean κ, 0.456 and 0.285 respectively). For bleb detection, intertechnique and interobserver agreements were fair and slight respectively (mean κ, 0.312 and 0.116 respectively) whereas both were slight for detection of branches arising from the sac (mean κ, 0.151 and 0.070 respectively).

CONCLUSION

MR angiography at 3T has a high sensitivity for the detection of UIA. However, it remains significantly inferior to DSA for morphological characterization of UIA.

Follow-up of intracranial aneurysms treated by flow diverter: comparison of three-dimensional time-of-flight MR angiography (3D-TOF-MRA) and contrast-enhanced MR angiography (CE-MRA) sequences with digital subtraction angiography as the gold standard

Background and purpose

Follow-up of intracranial aneurysms treated by flow diverter with MRI is complicated by imaging artifacts produced by these devices. This study compares the diagnostic accuracy of three-dimensional time-of-flight MR angiography (3D-TOF-MRA) and contrast-enhanced MRA (CE-MRA) at 3 T for the evaluation of aneurysm occlusion and parent artery patency after flow diversion treatment, with digital subtraction angiography (DSA) as the gold standard.

Materials and methods

Patients treated with flow diverters between January 2009 and January 2013 followed by MRA at 3 T (3D-TOF-MRA and CE-MRA) and DSA within a 48 h period were included in a prospective single-center study. Aneurysm occlusion was assessed with full and simplified Montreal scales and parent artery patency with three-grade and two-grade scales.

Results

Twenty-two patients harboring 23 treated aneurysms were included. Interobserver agreement using simplified scales for occlusion (Montreal) and parent artery patency were higher for DSA (0.88 and 0.61) and CE-MRA (0.74 and 0.55) than for 3D-TOF-MRA (0.51 and 0.02). Intermodality agreement was higher for CE-MRA (0.88 and 0.32) than for 3D-TOF-MRA (0.59 and 0.11). CE-MRA yielded better accuracy than 3D-TOF-MRA for aneurysm remnant detection (sensitivity 83% vs 50%; specificity 100% vs 100%) and for the status of the parent artery (specificity 63% vs 32%; sensitivity 100% vs 100%).

Conclusions

At 3 T, CE-MRA is superior to 3D-TOF-MRA for the evaluation of aneurysm occlusion and parent artery patency after flow diversion treatment. However, intraluminal evaluation remains difficult with MRA regardless of the sequence used.

One-year MR angiographic and clinical follow-up after intracranial mechanical thrombectomy using a stent retriever device

BACKGROUND AND PURPOSE

Little is known about the consequences of arterial wall damage that may be due to mechanical endovascular thrombectomy. Our aim was to perform 1-year MR angiographic and clinical follow-up of patients treated with mechanical endovascular thrombectomy using the Solitaire device.

MATERIALS AND METHODS

Patients with stroke treated between August 2010 and July 2012 were prospectively evaluated with a minimum follow-up of 1 year after mechanical endovascular thrombectomy. Angiographic follow-up was performed on a 3T MR imaging scanner and included intracranial artery TOF MRA and supra-aortic artery gadolinium-enhanced MRA. Images were assessed to detect arterial abnormalities (stenosis, occlusion, dilation) and were compared with the final post-mechanical endovascular thrombectomy run to differentiate delayed and pre-existing abnormalities. Clinical evaluation was performed with the mRS and the 36-Item Short-Form Health Survey questionnaire quality-of-life scale.

RESULTS

Thirty-nine patients were angiographically assessed at the mean term of 19 ± 4 months. MRA showed intracranial artery abnormalities in 10 patients, including 5 delayed intracranial artery abnormalities in 4 patients (4 stenoses and 1 dilation), 4 cases of pre-existing intracranial artery stenosis, and 2 occlusions. Pre-existing etiologic cervical artery stenosis or occlusion was observed in 2 patients. All these patients remained asymptomatic during the follow-up period. A significant clinical improvement was observed at 1-year follow-up in comparison with 3-month follow-up (P < .0001), with a good outcome achieved in 62.5% of patients and an acceptable quality of life restored.

CONCLUSIONS

One-year follow-up identifies delayed asymptomatic arterial abnormalities in patients treated with the Solitaire device.

Analysis of recanalization after endovascular treatment of intracranial aneurysm (ARETA trial): presentation of a prospective multicenter study

PURPOSE

Aneurysm recanalization is a main concern after endovascular treatment of intracranial aneurysms. But to date, no systematic analysis of the risk factors affecting its occurrence has been conducted in a large series of patients. Analysis of Recanalization after Endovascular Treatment of intracranial Aneurysm (ARETA) is a multicenter, prospective trial whose aim is to collect a large series of patients treated endovascularly to analyze factors affecting aneurysm recanalization.

STUDY DESIGN

Patients with ruptured or unruptured aneurysms treated endovascularly will be enrolled from December 2013 to December 2014 in 19 participating centers in France. Patient and aneurysm characteristics will be recorded as well as the type of endovascular treatment and the occurrence of procedural or post-procedural complications. Post-procedural and follow-up imaging after one year will be analyzed independently by two readers using a 3-grade scale (complete occlusion, neck remnant, or aneurysm remnant). The progression of aneurysm occlusion will also be evaluated (improved, stable, or worsened). Aneurysm occlusion at one year and progression of aneurysm occlusion will be analyzed in light of patient, aneurysm, and treatment factors.

CONCLUSION

ARETA is a large, prospective, multicenter trial designed to assess predictive factors of aneurysm recanalization after endovascular treatment of intracranial aneurysms.

The effectiveness of 3T time-of-flight magnetic resonance angiography for follow-up evaluations after the stent-assisted coil embolization of cerebral aneurysms

BACKGROUND

Artifacts introduced by stents limit the value of magnetic resonance (MR) imaging as a follow-up modality after the stent-assisted coil embolization of cerebral aneurysms.

PURPOSE

To investigate the usefulness of 3 Tesla (3T) time-of-flight (TOF) MR angiography (MRA) for the follow-up evaluation.

MATERIAL AND METHODS

Twenty-two aneurysms of 20 patients treated with stent-assisted coil embolization were followed up with 3T TOF MRA and digital subtraction angiography (DSA) with three-dimensional rotational angiography (3DRA). The status of coiled aneurysms was compared with 3T TOF MRA and DSA with 3DRA in terms of complete occlusion, residual neck, and residual aneurysm. TOF MRA at 3T was performed 1 day before DSA with 3DRA, with a mean follow-up period of 20.1 ± 10.8 months.

RESULTS

Twenty (90.9%) of 22 cases were concordant between the two modalities. The degree of agreement and correlation between them were high (κ=0.771, P<0.001; r=0.832 and P<0.001). When evaluating the status of residual neck, the sensitivity was 80% (4/5 cases); specificity was not available because there were no cases of complete occlusion. For the status of residual aneurysm, the sensitivity and specificity were 94.1% (16/17 cases) and 100% (all 5 cases), respectively.

CONCLUSION

TOF MRA at 3T with source images could be useful as a non-invasive follow-up modality after the stent-assisted coil embolization of cerebral aneurysms. Further study with a larger patient sample is needed to confirm the effectiveness of 3T TOF MRA.

Late onset aneurysm development following radiosurgical obliteration of a cerebellopontine angle meningioma

The development of de novo intracranial aneurysms following stereotactic radiosurgery for intracranial pathology is a rare complication secondary to vascular injury. Typically, these aneurysms develop within the first few years after radiation surgery. We present the first case of an aneurysm developing 10 years after radiosurgery for a cerebellopontine angle meningioma. This case highlights the importance of careful long-term follow-up of patients who undergo radiosurgery for lesions abutting major vessels and/or who suffer post-radiation complications.

Late onset aneurysm development following radiosurgical obliteration of a cerebellopontine angle meningioma

The development of de novo intracranial aneurysms following stereotactic radiosurgery for intracranial pathology is a rare complication secondary to vascular injury. Typically, these aneurysms develop within the first few years after radiation surgery. We present the first case of an aneurysm developing 10 years after radiosurgery for a cerebellopontine angle meningioma. This case highlights the importance of careful long-term follow-up of patients who undergo radiosurgery for lesions abutting major vessels and/or who suffer post-radiation complications.

Is long-term follow-up of adequately coil-occluded ruptured cerebral aneurysms always necessary? A single-center study of recurrences after endovascular treatment

PURPOSE

Aneurysm recurrence following coil occlusion is well recognized. However, there is controversy as to how long these patients should be followed up after coiling to detect reopening. We aimed to identify the rate of late reopening and the risk factors for reopening in a large single-center cohort of ruptured aneurysms that appeared adequately occluded at 6 months. We also aimed to assess whether rates of recurrence have altered over time with improving coil and angiographic technology.

METHODS

Patients treated between 1996 and 2010 were assessed and those with both 6-month initial and subsequent long-term follow-up with either digital subtraction angiography or magnetic resonance angiography were included. Aneurysms were stratified by features such as size, neck width, anatomical location and time of treatment: 1996-2005 (cohort 1) and 2006-2010 (cohort 2). ORs for risk of recurrence were calculated for aneurysm features and rates of recurrence in each cohort were compared using a χ(2) test.

RESULTS

437 patients with 458 adequately occluded aneurysms at 6 months had mean long-term follow-up of 31 months; 57 (12.4%) were large (≥ 10 mm) and 104 (22.7%) were wide-necked (>4 mm). Nine aneurysms (2%) showed significant late anatomical deterioration whereby retreatment was considered or undertaken. The risk was greater for large aneurysms (≥ 10 mm) (OR 15.61, 95% CI 3.79 to 64.33, p=0.0001) or wide-necked aneurysms (>4 mm) (OR 12.70, 95% CI 2.60 to 62.13, p=0.0017). The frequency of significant late anatomical deterioration and retreatment was also less common in those treated in cohort 2 (p<0.05). No completely occluded aneurysm at 6 months demonstrated significant late recurrence.

CONCLUSIONS

Most aneurysms adequately occluded at 6 months did not show evidence of late recurrence. Large and wide-neck aneurysms are, however, at greater risk of later recurrence.

Neuro-Ophthalmology Annual Review

The aim of this study was to update the practicing ophthalmologist on the English-language neuro-ophthalmology literature from the prior year. This study is a review of English-language literature from August 1, 2012, to August 1, 2013. The authors searched PubMed articles published from August 1, 2012, to August 1, 2013, limited to English-language publications including original articles, review articles, and case reports and excluding letters to the editor, unpublished work, and abstracts. We researched the following topics: pupillary abnormalities, eye movement dysfunction, neuromuscular diseases, optic neuropathies, optic neuritis and demyelinating disease including multiple sclerosis, lesions of the chiasm and posterior primary visual pathways, elevated intracranial pressure, tumors and aneurysms affecting the visual pathways, vascular diseases, higher visual functions, and neuroimaging advances. We intend to share clinically relevant literature of the past year with the practicing ophthalmologist. We aimed to highlight remarkable and interesting literature rather than exhaustively including all new neuro-ophthalmological publications of the year. We reviewed literature in the past year with a focus on relevance and novelty. This review updates the comprehensive ophthalmologist on neuro-ophthalmic topics.

WEB-DL endovascular treatment of wide-neck bifurcation aneurysms: short- and midterm results in a European study

BACKGROUND AND PURPOSE

Flow disruption with the WEB-DL device has been used safely for the treatment of wide-neck bifurcation aneurysms, but the stability of aneurysm occlusion after this treatment is unknown. This retrospective multicenter European study analyzed short- and midterm data in patients treated with WEB-DL.

MATERIALS AND METHODS

Twelve European neurointerventional centers participated in the study. Clinical data and pre- and postoperative short- and midterm images were collected. An experienced interventional neuroradiologist independently analyzed the images. Aneurysm occlusion was classified into 4 grades: complete occlusion, opacification of the proximal recess of the device, neck remnant, and aneurysm remnant.

RESULTS

Forty-five patients (34 women and 11 men) 35-74 years of age (mean, 56.3 ± 9.6 years) with 45 aneurysms treated with the WEB device were included. Aneurysm locations were the middle cerebral artery in 26 patients, the posterior circulation in 13 patients, the anterior communicating artery in 5 patients, and the internal carotid artery terminus in 1 patient. Forty-two aneurysms were unruptured. Good clinical outcome (mRS < 2) was observed in 93.3% of patients at the last follow-up. Adequate occlusion (complete occlusion, opacification of the proximal recess, or neck remnant) was observed in 30/37 patients (81.1%) in short-term follow-up (median, 6 months) and in 26/29 patients (89.7%) in midterm follow-up (median, 13 months). Worsening of the aneurysm occlusion was observed in 2/28 patients (7.1%) at midterm follow-up.

CONCLUSIONS

The results suggest that the WEB endovascular treatment of wide-neck bifurcation aneurysms offers stable occlusion in a class of aneurysms that are historically unstable. Additionally, our data show that opacification of the WEB recess can be delineated from true neck or aneurysm remnants.

[Neuroimaging follow-up of cerebral aneurysms treated with endovascular techniques]

There are no specific recommendations in clinical guidelines about the best time, imaging tests, or intervals for following up patients with intracranial aneurysms treated with endovascular techniques. We reviewed the literature, using the following keywords to search in the main medical databases: cerebral aneurysm, coils, endovascular procedure, and follow-up. Within the Cerebrovascular Disease Group of the Spanish Society of Neuroradiology, we aimed to propose recommendations and an orientative protocol based on the scientific evidence for using neuroimaging to monitor intracranial aneurysms that have been treated with endovascular techniques. We aimed to specify the most appropriate neuroimaging techniques, the interval, the time of follow-up, and the best approach to defining the imaging findings, with the ultimate goal of improving clinical outcomes while optimizing and rationalizing the use of available resources.