Raymond-Roy Occlusion Classification Research Articles

Early experience with the Penumbra SMART coil in the endovascular treatment of intracranial aneurysms: Safety and efficacy.

Penumbra SMART coils differ from traditional microcoils used for endovascular coil embolization of intracranial aneurysms (IAs) in that they (1) become progressively softer from their distal to proximal end, rather than being of uniform stiffness, (2) have a tight conformational structure, and (3) have a more robust stretch-resistance platform. These properties aid in preventing microcatheter prolapse and coil herniation during coil deployment and in filling small pockets of the aneurysm sac. To determine the safety and efficacy of this device, the records of 17 consecutive patients with IAs treated with SMART coils were retrospectively analyzed. Thirteen female and four male patients were identified. Eleven patients presented with subarachnoid hemorrhage, four had recurrent aneurysms, and two had incidentally discovered aneurysms. Twelve aneurysms (two of which were recurrent) were treated with stand-alone coiling, three were treated with stent-assisted coiling, and two with flow diversion with adjuvant coiling. Microcatheter prolapse occurred in one case of a recurrent aneurysm, due to mechanical limitations imposed by a stent placed during prior coiling. Raymond-Roy Occlusion Classification (RROC) I or II occlusion was achieved in 12 aneurysms, including all 10 undergoing primary stand-alone coiling. Of the five RROC III occlusions, two were expected given treatment with flow diversion, while the other three occurred in complex, recurrent aneurysms. One patient suffered a thromboembolic complication of unclear clinical significance. The Penumbra SMART coil is a safe and effective device for the endovascular treatment of IAs. Follow-up studies are required to establish long-term results.

The effect of basilar artery bifurcation angle on rates of initial occlusion, recanalization, and retreatment of basilar artery apex aneurysms following coil embolization.

Arterial bifurcations are common locations for aneurysm development given the altered hemodynamic forces and shear stress variations present at these locations. Recent reports indicate that a wide basilar artery bifurcation angle is an independent predictor of aneurysm development, growth, and subsequent rupture. To determine the effect of basilar artery bifurcation angle on rates of initial occlusion, recanalization, and retreatment of basilar artery apex aneurysms following coil embolization, the records of 46 patients with basilar artery apex aneurysms treated with endovascular coil embolization from 2007 to 2013 were analyzed. A wide basilar artery bifurcation angle was associated with a Raymond-Roy Occlusion Classification (RROC) III occlusion in univariate analysis, but was not a statistically significant factor in multivariate modeling. An increasing basilar artery bifurcation angle was not associated with aneurysm recanalization or retreatment following coil embolization. Increasing packing density (p < .01) was the only statistically significant predictor of a RROC I or II closure. The initial RROC designation was the most powerful predictor of both eventual aneurysm recanalization (p = .01) and retreatment (p = .02). While increasing aneurysm size (p < .01), increasing aneurysm volume (p < .01), and increasing neck size (p < .01) were associated with wide basilar artery bifurcation angles, neck size (p = .03) was the only statistically significant predictor of basilar artery bifurcation angle on multivariate analyses. Basilar artery bifurcation angle fails to predict rates of initial occlusion, recanalization, and retreatment on multivariate modeling in our series. Basilar artery apex aneurysm neck size independently correlates with basilar artery bifurcation angle.

Major recanalization occurs more often in young patients after unruptured aneurysm coil embolization.

The recanalization rate after coil embolization of unruptured aneurysms was compared between young and old age groups. From May 2003 to December 2010, 636 patients with 715 saccular unruptured intracranial aneurysms (UIA) underwent endovascular coiling and were followed for at least 6 months. For comparative analysis, patients were categorized into two groups according to age 40: 42 patients with 46 aneurysms who were 40 years or younger (young age group) and 594 patients with 669 aneurysms who were older than 40 years (old age group). Angiographic and clinical outcomes including recanalization rates were compared. Angiographically, class 1 or 2 occlusion according to the Raymond-Roy Occlusion Classification system was achieved in 89.2 % of the patients (91.3 % in the young age group and 89.1 % in the old age group, p = 0.74). Procedure-related complication rate was 2.2 % and 3.4 % in the young and the old age group (p = 0.16), respectively. The mean follow-up duration was 30.51 ± 18.59 months. Major recanalization occurred in seven aneurysms (15.2 %) in the young age group and in 44 aneurysms (6.6 %) in the old age group (p = 0.03). Retreatment was performed in seven patients (15.2 %) in the young age group and in 35 patients (5.2 %) in the old age group (p = 0.01). The present study showed that the technical feasibility and safety of endovascular coiling for UIA did not differ between the two age groups. However, the major recanalization rate was higher in the young age group.

Validation of the Modified Raymond–Roy classification for intracranial aneurysms treated with coil embolization

BackgroundThe Raymond–Roy Occlusion Classification (RROC) qualitatively assesses intracranial aneurysm occlusion following endovascular coil embolization. The Modified Raymond–Roy Classification (MRRC) was developed as a refinement of this classification scheme, and dichotomizes...

A New Aneurysm Occlusion Classification after the Impact of Flow Modification

A new classification is proposed for cerebral aneurysms treated with any endovascular technique, for example, coiling with or without adjunctive devices, flow diversion, intrasaccular flow modifiers, or any combination of the above. Raymond-Roy Occlusion Classification is expanded with novel subgroups such as class 1 represents complete occlusion and is subdivided if a branch is integrated to, or originated from, the aneurysm sac; class 2 represents neck filling; class 3 represents incomplete occlusion with aneurysm filling as in the previous classification; and class 4 describes the immediate postoperative status after extra- or intrasaccular flow modification treatment. A new concept, "stable remodeling," is included as class 5, which represents filling in the neck region that stays unchanged or reduced, as shown with at least 2 consecutive control angiographies, at least 6 months apart, for not <1 year, or the remodeled appearance of a dilated and/or tortuous vessel in continuation with the parent artery without sac filling.

Coil Embolization of Wide-Neck Bifurcation Aneurysms Using a Single-Balloon Microcatheter

Background: Coil embolization of wide-neck cerebral aneurysms frequently requires stent or balloon assistance. Such approaches to coil embolization increase the procedural complexity, adding risk and cost. Objective: To describe a series of coil embolization procedures performed using a single-balloon microcatheter to treat wide-neck aneurysms and establish the safety, feasibility and efficacy of this technique. Methods: A retrospective review was performed to identify cases in which the Ascent balloon (Codman Neurovascular, Raynham, Mass., USA) was used as a single-balloon microcatheter for aneurysm coil embolization at two institutions. Clinical, demographic and angiographic data were obtained, and aneurysm volumes as well as packing densities (PD) were calculated. Results: Eight cerebral aneurysms were treated using this technique. Six of these were unruptured. The aneurysms had an average neck diameter of 3.7 mm, and the maximum dimension ranged from 5 to 11 mm, with a mean of 7.5 mm. The mean aspect ratio was 2.07. The mean volume of the aneurysms was 180.38 mm³. The average PD achieved in these 8 aneurysms was 41.79%. Complete occlusion with coil embolization [Raymond-Roy Occlusion Classification (RROC) 1] was achieved in all cases except one, where a small residual was left deliberately and the occlusion grade was RROC 2. There were no intraprocedural complications. Conclusion: This initial experience demonstrates the feasibility and immediate outcomes of a single-balloon microcatheter technique in coil embolization of wide-neck cerebral aneurysms. This technique may be used to achieve a high PD, comparable to that obtained with stent-assisted coiling or coiling alone, while avoiding permanent stent placement and potentially reducing thromboembolic complications.

Predictors of treatment failure following coil embolization of intracranial aneurysms

We present a retrospective review of 357 consecutive patients with 419 aneurysms treated with coil embolization. Although incomplete occlusion and recurrence of intracranial aneurysms following coil embolization is a well-known problem, the factors that influence and predict treatment failure are still debated. For this study, we excluded non-coiling endovascular techniques (flow diversion) and non-saccular aneurysms (fusiform). The modified Raymond–Roy occlusion classification (MRRC) was used to grade the aneurysms. Treatment failure was defined as filling of the aneurysm dome (MRRC Class IIIa or IIIb) at the first angiographic follow-up (average 8months). Univariate statistical tests were employed to select variables for incorporation into a multivariable logistic regression model. Multivariate analysis identified greater aneurysm volume (p<0.001), packing density (PD) less than 31% (p=0.007) and initial MRRC Class IIIb (p<0.001) as predictors of treatment failure. Incomplete neck coverage with coils was associated with treatment failure in univariate but not multivariate analysis. Class IIIb status was more predictive of treatment failure compared to all Class III (odds ratio 168 versus 14.4). Clinical outcomes were similar in both groups except that there were more retreatments in the treatment failure group (p<0.001). Aneurysm volume, PD and initial occlusion class are associated with angiographic outcome, consistent with prior literature. The MRRC is a powerful predictor of treatment failure. These results will be useful in the effort to both prevent and predict treatment failure after coil embolization, however, they should be verified in a prospective study.

An update to the Raymond–Roy Occlusion Classification of intracranial aneurysms treated with coil embolization

BackgroundThe Raymond–Roy Occlusion Classification (RROC) is the standard for evaluating coiled aneurysms (Class I: complete obliteration; Class II: residual neck; Class III: residual aneurysm), but not all Class III aneurysms...

Angiographic outcome of intracranial aneurysms with neck remnant following coil embolization

BackgroundThe degree of aneurysm occlusion following coil embolization has an impact on aneurysm recanalization.ObjectiveTo explain the natural history of intracranial aneurysms with neck remnant, Raymond–Roy Occlusion Classification (RROC) class II.MethodsA...

The LVIS Jr. microstent to assist coil embolization of wide-neck intracranial aneurysms: clinical study to assess safety and efficacy

This study was aimed to assess clinical safety and efficacy of the LVIS Jr. microstent in stent-assisted coil embolization of wide-neck intracranial aneurysms. IRB approved single-center interventional clinical study in 22 patients (10 females, 12 males, mean age 55, age range 33-74 years) for the endovascular treatment of wide-neck aneurysms. After obtaining informed consent, patients were included according to the following criteria: aneurysm fundus-to-neck ratio < 2 or neck diameter > 4 mm, and a parent vessel diameter of ≤3.5 mm. Primary end point for clinical safety was absence of death, absence of major or minor stroke, and absence of transient ischemic attack. Primary end point for treatment efficacy was complete angiographic occlusion according to the Raymond-Roy Occlusion Classification (RROC) immediately after the procedure and at follow-up after 3 and 6 months on magnetic resonance imaging (MRI). In 20/22 (91 %) of patients, the primary end point of safety was reached; in the two remaining patients, transient ischemic attack, but no permanent deficit was observed; in 16/22 (73 %), efficient occlusion (RROC1) was reached, and in 6/22 (27 %), a residual neck remained (RROC2). Single [seven with antegrade, two in crossover configuration, and four with "first-balloon-then-stent" (FBTS) technique] or double-stent (eight patients with Y configuration and one patient with X configuration) deployment was technically successful in all cases. Deployment of the LVIS Jr. microstent in various single- or double-stent configurations is safe and effective to assist the treatment of intracranial wide-neck aneurysms.

Aneurysm embolization grade: a predictive tool for aneurysm recurrence after coil embolization

Coil embolization has gained importance in the management of intracranial aneurysms over the past decade. However, the recurrence risk after embolization mandates closer follow-up than surgical clip ligation. Currently, there is no reliable system for predicting aneurysm sac thrombosis. An aneurysm embolization grade (AEG) reported previously by the senior author (EMD) has been proposed as a tool for predicting the durability of aneurysm occlusion based on hemodynamic characteristics. Here, we present our internal validity results. AEG and Raymond-Roy Occlusion Classification (RROC) scores were prospectively assigned to all aneurysms coiled from June 2008 to June 2011. The prospectively assigned AEG and RROC scores from the cerebral angiograms were collected for data analysis and validity assessment of the AEG system. 110 consecutive patients who had aneurysm coil embolization were included in this study. The post-coiling AEG significantly predicted follow-up angiographic filling characteristics. Pairwise comparisons revealed that the follow-up AEG for those initially scored 'A' (complete obliteration) was significantly better than the contrast-flow groups. Significant differences were also noted between contrast-stasis and contrast-flow groups. A pairwise comparison between RROC scores demonstrated that only the RROC Type 1 could be used to predict follow-up occlusion durability. Stent placement in wide-neck aneurysms had no effect on initial AEG, RROC, or long-term occlusion durability. Packing density significantly predicted initial AEG and RROC, but had no effect on long-term occlusion. The AEG system is uniquely based on angiographic filling characteristics of the aneurysm, and this study demonstrated its high predictive value for determining aneurysm sac thrombosis. Assigning an AEG to the aneurysm can guide the neurointerventionalist in discussions with the patient regarding the probability of aneurysm recurrence and potential need for retreatment.

A prospective single-center analysis of the safety and efficacy of the HydroCoil embolization system for the treatment of intracranial aneurysms

The HydroCoil embolization system is a helical platinum coil coated with a polymeric hydrogel that expands when it contacts aqueous solutions to increase filling volumes, improve mesh stability, and possibly elicit a healing response within the aneurysm. In this paper, the authors report the 1-year recurrence and complication rates of 67 aneurysms embolized with the HydroCoil system. Sixty-four consecutive patients (67 total aneurysms) with small (< or =7 mm), large (8-15 mm), very large (16-24 mm), and giant (> or =25 mm) aneurysms in the anterior and posterior intracranial circulations were treated with HydroCoils between March 2003 and September 2004. All aneurysms were embolized by the senior author (A.S.B) with HydroCoils alone or in combination with bare platinum coils, until either there was no further angiographic contrast filling of the aneurysm or the microcatheter was pushed out of the dome by the coil mass. Balloon assistance was used in three cases and combined Neuroform stent-coil embolization in eight other cases. To evaluate the safety and 1-year efficacy of the HydroCoil system, periprocedural complications were recorded, and angiographic recurrences were categorized using the Raymond-Roy Occlusion Classification (RROC) system. The 1-year aneurysm recurrence rate independent of size was 15% in patients treated with HydroCoils. Seventy percent of the patients had stable occlusions. The recurrence rate for small aneurysms was 3.7%, and the combined recurrence rate for small and large aneurysms was 6%. Fifteen percent of the aneurysms initially categorized as RROC Type 2 or 3 with stasis of contrast material at the time of initial embolization improved in RROC type, allowing the authors to develop the aneurysm embolization grade to predict recurrence. The neurological complication rate was 14.9%, of which 4.5% represented permanent neurological deficits. The HydroCoil embolization system is safe and provides excellent 1-year occlusion of small and large aneurysms with initial RROC Type 1, as well as those with RROC Types 2 and 3 with stasis of contrast material at the time of embolization. Very large and giant aneurysms were not as successfully occluded with this system. Treatment of large and giant internal carotid artery aneurysms was more likely to result in cranial nerve palsies and postembolization headaches than treatment in other locations. The aneurysm embolization grade the authors developed using the results of this study accurately predicted 1-year recurrence rates based on the immediate postembolization angiographic characteristics of the treated aneurysm.