Coil Embolization Of Unruptured Aneurysms Research Articles

Three-dimensional reconstruction imaging by C-arm computed tomography accurately visualizes in-stent neointimal formation in patients with stent-assisted coil embolization.

Stent apposition to the vessel wall and in-stent neointimal formation after stent-assisted coil embolization for intracranial aneurysm are important factors associated with postoperative thromboembolic complications. No assessment methods have been established to depict 3-dimensional (3D) all-round in-stent neointimal formation. To demonstrate the superiority of Dyna-3D imaging assessment as a modality for all-round ISNF in comparison with conventional two-dimensional digital subtraction angiography (2D-DSA). Consecutive patients who underwent braided stent-assisted coil embolization for unruptured aneurysm between November 2016 and September 2021 were enrolled. Radiological assessments for stent apposition to the parent vessel after stent deployment and in-stent neointimal formation after 3 months were obtained. Dyna-3D was reconstructed by overlapping a plain image showing stent struts with a rotational DSA image showing the vessel lumen. Reconstructed Dyna-3D images can be rotated to any angle on the screen to evaluate to stent apposition around the vessel and in-stent neointimal formation in 3D, for comparison with 2D-DSA evaluations. Among the 73 patients enrolled, 70 patients (96%) showed complete stent wall apposition on Dyna-3D. Higher intra-rater agreement was confirmed on assessment of in-stent neointimal formation with Dyna-3D (Cohen's κ = 0.811) than with conventional 2D-DSA (Cohen's κ = 0.517). in-stent neointimal formation could not be confirmed on conventional imaging in 9 cases (16%) and on Dyna-3D in 2 cases (3%). The number of in-stent neointimal formations rated as stent wire completely outside the endothelial line was significantly higher with Dyna-3D than with 2D-DSA (p = 0.0001). All-round 3D evaluation by Dyna-3D imaging appears useful for confirming in-stent neointimal formation after braided stent deployment in patients after stent-assisted coil embolization.

Risk factors for recanalization of dense coil packing for unruptured cerebral aneurysms in endovascular coil embolization: Analysis of a single center’s experience

In coil embolization of cerebral aneurysms, inadequate packing is known to increase the probability of recanalization. Even tightly embolized aneurysms may be recanalized, but predictive factors for recanalization have not been fully investigated. This retrospective study aimed to identify risk factors for recanalization of treated aneurysms with a volume embolization ratio (VER) ≥ 25%. A total of 301 unruptured aneurysms in 248 patients who underwent coil embolization between March 2012 and January 2021 were analyzed. Cases involving dissecting aneurysm, intraluminal thrombosis, parent artery occlusion, intraoperative rupture, re-treatment, rupture the day after surgery, postoperative coil migration, and postoperative parent artery occlusion were excluded due to the inaccuracy of VER. A total of 105 aneurysms (34.9%) treated with VER ≥ 25% were extracted. Clinical features (age, sex, medical history, family history), anatomical features (shape, location, aneurysm size, inflow angle, and volume), procedural features (stent-assisted, Raymond-Roy occlusion classification [RROC] immediately after treatment, re-treatment rate), and follow-up period were compared between Recanalization and Non-recanalization groups. Predictors of recanalization were determined using logistic regression and receiver operating characteristic (ROC) curve analyses. Eleven aneurysms were recanalized. In multivariate analysis, RROC class 3 (odds ratio [OR] 11.0; 95% confidence interval [CI] 2.03–59.4) and aneurysm volume (OR 1.005; 95%CI 1.001–1.008) were independent predictors of recanalization. ROC curve analysis showed optimal cutoff values for aneurysm volume of 69.5 mm3 (sensitivity, 81.8%; specificity, 72.3%). In coil embolization of unruptured aneurysms that VER ≥ 25%, cases with RROC class 3 or high aneurysm volume may be associated with a higher risk of recanalization, and should be carefully followed-up.

The inhibition rate estimated using VerifyNow can help to predict the thromboembolic risk of coil embolization for unruptured intracranial aneurysms

BackgroundThe role of the inhibition rate of VerifyNow in assessing the thromboembolic risk of coil embolization for unruptured intracranial aneurysms is unclear.ObjectiveTo carry out a retrospective study to determine whether...

Long-term Durability of Coil Embolization for Unruptured Aneurysm after Introduction of the Neck-bridge Stent: Comparison between the Pre-stent Era and the Stent Era.

More complex aneurysms can be treated by coil embolization with neck-bridge stent assistance. However, concerns about postprocedural ischemic or hemorrhagic complications remain. In this study, we assessed the long-term durability after introduction of neck-bridge stent in the context of coil embolization for unruptured aneurysm by comparing re-treatment and neurological events between the pre-stent and stent eras. Unruptured aneurysms treated by coil embolization between April 2005 and May 2018 were analyzed retrospectively. We divided cases into two groups: the pre-stent era and the stent era. The cumulative rate of re-treatment and neurological events were assessed and compared. During the period, 177 aneurysms were treated in the pre-stent era and 354 aneurysms were treated in the stent era. The median follow-up was 55 months. In the stent era, the dome/neck (D/N) ratio was significantly lower (P <0.001) and the number of aneurysms located at the posterior circulation was higher (P <0.001). A stent was used in 31.92% of cases in the stent era. The cumulative rate of re-treatment was significantly higher in the pre-stent era than it was in the stent era in univariate and multivariate analyses (P = 0.008, P = 0.008, respectively). The cumulative rate of neurological events was not significantly different between the two groups. The re-treatment rate has been improved without increasing neurological complications after introduction of the neck-bridge stent.

Abstract WMP33: Peri-operative Dual Antiplatelet Therapy for the Coil Embolization of Unruptured Brain Aneurysms: The Efficacy and the Side Effect

Backgrounds: Optimal dose and duration of antiplatelet therapy before / after the coil embolization of unruptured aneurysm has not been established, yet. The dual antiplatelet therapy (DAPT) using aspirin and clopidogrel started 3 to 7 days before operation has been a commonly used antiplatelet protocol, although few studies have done to evaluate the relationship between the duration of the pre-operative DAPT and its efficacy / side effects. In the present study, the different durations of the pre-operative DAPT and their related “efficacy / side effect” was retrospectively analyzed. Method: A total of 232 unruptured brain aneurysm patients (male, n=62; median age, 61 y) who underwent coil embolization were enrolled in this study. Fifty-two (22%) patients underwent stent assisted coil embolization. The patients were categorized into 3 different groups depending on the duration of the DAPT: Group A (within 3days), Group B (4-6 days) and Group C (7 days or longer). The platelet aggregation profiles are evaluated on the day of procedure. Post-operative MRI, the neurological findings and the peri-operative hemorrhagic events between the 3 groups were compared. Results: Diffusion weighted image (DWI) performed the day after the operation showed that 169 (73%) patients had any high intensity lesion in the ipsilateral perfusion area of the treated artery, and 8 (3%) represented symptomatic infarction. The both adenosine diphosphate (ADP) and collagen aggregation were significantly decreased in the group of longest DAPT period (vs Group A (ADP; 45% vs 15%, P &lt;0001, collagen 99% vs 90% P =0.008), vs Group B (ADP; 45% vs 27%, P =0.032, collagen 99% vs 94%, P =0.137)). The symptomatic infarction after operation tended to decrease with longer DAPT period without statistical significance. The rate of hemorrhagic complication was not increased by the longer DAPT period during the observation period. Conclusion: Longer DAPT period significantly reduced both the ADP and collagen aggregation. The rate of symptomatic thromboembolic event tended to decrease with longer DAPT period without statistical significance. With increased number of patient, longer DAPT protocol may reduce the thromboembolic event without increasing the hemorrhagic complication rate.

P2Y12 Reaction Units Threshold for Implementing Modified Antiplatelet Preparation in Coil Embolization of Unruptured Aneurysms: A Prospective Validation Study.

Purpose To identify and apply an optimized P2Y12 reaction units (PRU) threshold for implementing modified antiplatelet preparation to prevent thromboembolic events in patients nonresponsive to clopidogrel (clopidogrel nonresponders) undergoing coil embolization of unruptured aneurysms and to evaluate the clinical validity. Materials and Methods The optimal PRU threshold for prediction of thromboembolic events was determined with the Youden index in post hoc analysis of a previous, prospectively enrolled cohort of 165 patients in whom the antiplatelet regimen was not modified. This optimal PRU threshold was used to define clopidogrel nonresponders in a prospective validation study of 244 patients. Standard preparation (aspirin, clopidogrel) was maintained for 126 patients responsive to clopidogrel (clopidogrel responders, 51.6%), and modified preparation (aspirin, prasugrel) was prescribed prior to embolization for 118 clopidogrel nonresponders (48.4%). Fifty-seven clopidogrel nonresponders from the previous cohort who did not receive the modified preparation were included as a historical control group. Thromboembolic and bleeding events were compared among groups by using logistic regression analysis. Results Post hoc analysis from the previous cohort yielded PRU of at least 220 as the optimal threshold for modified preparation selection. The thromboembolic event rate of the clopidogrel responders (one of 126 [0.8%]) was lower than that of the historical control group that received standard preparation (seven of 57 patients [12.3%]; adjusted risk difference [RD], -10.1%; 95% confidence interval [CI]: -18.5, -1.7; P = .015) and was similar to that of clopidogrel nonresponders who received modified preparation (one of 118 [0.8%]; adjusted RD, -0.5%; 95% CI: -3.1, 2.1; P = .001 for noninferiority; P = .699 for superiority). Bleeding event rates did not differ among groups (four of 126 clopidogrel responders [3.2%] vs four of 57 clopidogrel nonresponders that received standard preparation [7.0%] [adjusted RD, -4.5%; 95% CI: -11.1, 3.4; P = .228] vs five of 118 clopidogrel nonresponders that received modified preparation [4.2%] [adjusted RD, -0.6%; 95% CI: -5.8, 4.2; P = .813]). Conclusion Patients undergoing coil embolization of unruptured aneurysms, regardless of clopidogrel responsiveness, had low thromboembolic risk when using PRU of at least 220 as the threshold for implementing modified antiplatelet preparation with prasugrel. © RSNA, 2016 Online supplemental material is available for this article.

Statins are not associated with short-term improved aneurysm healing in a rabbit model of unruptured aneurysms

BackgroundOwing to their anti-inflammatory effects and ability to stimulate production of extracellular matrix and chemotactic migration of mesenchymal progenitor cells, statins could potentially improve aneurysm healing after endovascular treatment.ObjectiveTo test...

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.

Thromboembolic complications in patients with clopidogrel resistance after coil embolization for unruptured intracranial aneurysms.

Antiplatelet resistance is known to be associated with symptomatic ischemic complication after endovascular coil embolization. The purpose of our study was to evaluate the relationship between antiplatelet resistance and clinically silent thromboembolic complications using DWI in patients who underwent coil embolization for unruptured intracranial aneurysm. Between October 2011 and May 2013, 58 patients with 62 unruptured aneurysms who were measured for antiplatelet response using VerifyNow assay and underwent elective coil embolization for an unruptured aneurysm with posttreatment DWI were enrolled. Diffusion-positive lesions were classified into 3 groups according to the number of lesions (n=0 [grade 0], n<6 [grade I], and n≥6 [grade II]). The relationship between antiplatelet resistance and diffusion-positive lesions was analyzed. Sixty-two endovascular coiling procedures were performed on 58 patients. Clopidogrel resistance was revealed in 23 patients (39.7%) and diffusion-positive lesions were demonstrated in 28 patients (48.3%); these consisted of 19 (32.8%) grade I and 9 (15.5%) grade II lesions. Clopidogrel resistance was not relevant to the development of any diffusion-positive lesion (grade I and II, P=.789) but was associated with the development of multiple diffusion-positive lesions (grade II, P=.002). In the logistic regression prediction model, clopidogrel resistance showed significant correlation with the development of grade II lesions (P=.001). Multiple diffusion-positive lesions (≥6 in number) occurred more frequently in patients with clopidogrel resistance after endovascular coiling for unruptured aneurysms.

Abstract TP88: Tailored Periprocedural Antiplatelet Therapy for Coil Embolization of Unruptured Intracranial Aneurysms using Neck Size

Introduction and Hypothesis: Although periprocedural antiplatelet therapy (APT) for coil embolization of unruptured aneurysms (UAs) has been prevailing, its detailed regimens such as mode (single or dual), dose, and duration, are not yet well established. Recently, we have reported our retrospective data that dual APT better prevented ischemic complications from coiling in wide-necked aneurysms compared with single APT. The aim of this prospective study is to assess the efficacy of using the aneurysmal neck width to determine the mode of APT (single or dual) for coiling of UAs, especially focusing on the safety of single APT for narrow-necked aneurysms in prevention of ischemic complications. Methods: A total of 78 consecutive patients harboring UAs treated by endosaccular coil embolization at our institute between September 2009 and July 2012 were included. Stent-assisted cases were excluded. APT was started 4 days prior to the procedure, and UAs with narrow neck (&lt;4mm, 24 cases) received single APT (aspirin 100mg; group 1) while wide-necked cases (≥4mm, 54 cases) received dual APT (aspirin 100mg and clopidogrel 75mg ) were administered for one month. The incidence of both ischemic and hemorrhagic complications, and abnormality in postprocedural diffusion weighted imaging (DWI) in each group was assessed. Results: Symptomatic ischemic complications occurred in 3 (5.5%) cases in group 2 and none in group 1. DWI abnormalities were observed in 5 (20.8 %) in group 1 and 20 (37.0%) in group 2. In cases with adjunctive technique, there was no significant difference in the incidence of DWI positive cases between group 1 (3/13, 23.1%) and 2 (19/49, 38.8%) (P=0.16). Hemorrhagic complicationoccurred in only one case in group 2 (1.9%). Conclusions: In this series, single APT for coiling of narrow-necked aneurysms well prevented both periprocedural ischemic events and DWI positive lesions. In conclusion, this protocol, which determines the mode of APT by neck size, seems easy to use and could be beneficial in prevention of ischemic/hemorrhagic complications and from medico-financial aspect.

抗血栓薬の追加が奏功した脳動脈瘤塞栓術中血栓塞栓症の1例

抗血栓薬の追加が奏功した脳動脈瘤塞栓術中血栓塞栓症の1例

Enterprise stentとcoilを用いた瘤内塞栓術の血栓・塞栓性合併症についての考察

Enterprise stentとcoilを用いた瘤内塞栓術の血栓・塞栓性合併症についての考察

Subarachnoid Hyperattenuation on Flat Panel Detector–Based Conebeam CT Immediately after Uneventful Coil Embolization of Unruptured Intracranial Aneurysms

Flat panel detector-based CBCT can provide CT-like images of the brain without transferring patients from the angiography suite to a conventional CT facility. Conventional brain CT after uneventful endovascular treatment sometimes shows focal subarachnoid hyperattenuation with contrast leakage, mimicking SAH. Differentiating this finding from SAH is important for immediate postprocedural medical management. We investigated CBCT for detecting subarachnoid hyperattenuation immediately after coil embolization of unruptured cerebral aneurysms. Thirty-six patients with unruptured cerebral aneurysms undergoing CBCT immediately after uncomplicated coil embolization were included. The relationship between the presence of subarachnoid hyperattenuation and total volume of contrast medium injected, aneurysm size and location, and balloon and stent assistance during embolization was investigated. Statistical analyses were performed with the χ(2) test (P < .05). Nine of the 36 patients (25.0%) showed focal subarachnoid hyperattenuation within the relevant parent artery territory harboring the aneurysm. Subarachnoid hyperattenuation locations included the ipsilateral superior frontal sulcus (n = 5), the bilateral superior frontal sulcus (n = 1), and the ipsilateral superior frontal and precentral sulci (n = 3). Statistically significant differences were observed between the presence of a subarachnoid hyperattenuation and the total volume of contrast medium injected (P < .001) and aneurysm size (P < .05). Subarachnoid hyperattenuation can be detected by CBCT immediately after coil embolization for unruptured aneurysms. The increased amounts of contrast medium to be given before CBCT and the specific location of the hyperattenuation may help differentiate benign subarachnoid contrast leakage from SAH.

A multicenter registry of hydrocephalus following coil embolization of unruptured aneurysms: which patients are at risk and why it occurs

IntroductionUnexplained post-procedural events such as cerebral edema, inflammation, aseptic meningitis and hydrocephalus have been reported following unruptured cerebral aneurysm coiling. However, understanding of the etiology for these occurrences is limited...

Thromboembolic Complications of Elective Coil Embolization of Unruptured Aneurysms

We retrospectively evaluated whether antiplatelet preparation lowered the thromboembolic complication rate during the perioperative period. We reviewed 328 elective coil embolization procedures in which only microcatheters were used for coiling. No antiplatelet medication was prescribed before the procedure in 95 cases (29%, group 1), whereas antiplatelet therapy was used in 233 cases (71%, group 2; 61 [18.6%] with a single agent [aspirin or clopidogrel] and 172 [52.4%] with both agents). Antiplatelet agents were not given after coiling unless atherosclerosis, severe coil protrusion, or a thromboembolic complication occurred during the procedure. A thromboembolic complication was defined as a procedural thromboembolic event or transient ischemic attack or stroke occurring within 2 days of embolization. Thromboembolic complications occurred in 11 cases (3.4%): 6 (6.3%) in group 1 and 5 (2.1%) in group 2 (P = .085). In 195 cases (59.5%) treated by the single microcatheter technique, the risk of thromboembolic complications was low and not affected by antiplatelet preparation (1.8% [no preparation] vs 2.2% [preparation]; P = 1.000). However, in 133 cases (40.5%) treated by the multiple microcatheter technique, antiplatelet preparation significantly reduced the thromboembolic complication risk by 85.2% (12.8% [no preparation] vs 2.1% [preparation]; odds ratio, 0.148; 95% confidence interval, 0.027-0.798; P = .023). The aneurysms treated by the multiple microcatheter technique had more complex configurations for coiling (P < .001). The risk of hemorrhage was not increased by antiplatelet preparation (P = .171). Antiplatelet preparation lowered the periprocedural thromboembolic complication rate in unruptured aneurysms treated by the multiple microcatheter technique and did not increase the risk of hemorrhage. Therefore, antiplatelet preparation can help to reduce complications in patients in whom technical difficulties are expected without the risk of hemorrhage.

Monorail Snare Technique for the Recovery of Stretched Platinum Coils: Technical Case Report

Coil stretching represents a potentially hazardous technical complication not infrequently encountered during the embolization of cerebral aneurysms. Often, the stretched coil cannot be advanced into the aneurysm or withdrawn intact. The operator is then forced to attempt to retract the damaged coil, which may result in coil breakage, leaving behind a significant length of potentially thrombogenic stretched coil material within the parent vessel. To overcome this problem, we devised a technique to snare the distal, unstretched, intact portion of the platinum coil by use of the indwelling microcatheter and stretched portion of the coil as a monorail guide. We have used this technique successfully in four patients to snare coils stretched during cerebral aneurysm embolization. Three of these patients were undergoing Neuroform (Boston Scientific/Target, Fremont, CA) stent-supported coil embolization of unruptured aneurysms. In all cases, the snare was advanced easily to the targeted site for coil engagement by use of the microcatheter as a monorail guide. Once the intact distal segment of the coil was ensnared, coil removal was uneventful, with no disturbance of the remainder of the indwelling coil pack or Neuroform stent. A 2-mm Amplatz Goose Neck microsnare (Microvena Corp., White Bear Lake, MN) was placed through a Prowler-14 microcatheter (Cordis Corp., Miami, FL). The hub of the indwelling SL-10 microcatheter (Boston Scientific, Natick, MA) was then cut away with a scalpel, leaving the coil pusher wire intact, and removed. The open 2-mm snare was then advanced over the outside of the coil pusher wire and microcatheter. The snare and Prowler-14 microcatheter were then advanced into the guiding catheter (6- or 7-French) as a unit over the indwelling SL-10 microcatheter. By use of the SL-10 microcatheter and coil as a "monorail" guide, the snare was advanced over and beyond the microcatheter and the stretched portion of the coil until the snare was in position to engage the distal unstretched coil. At this point, the snare was then closed around the intact portion of the coil, and the microcatheters, snare, and coil were removed as a unit. The monorail snare technique represents a fast, safe, and easy method by which a stretched coil can be removed.

Intravenous abciximab for parent vessel thrombus during basilar apex aneurysm coil embolization: Case report and literature review

Background Parent vessel thrombus formation is a serious complication of intracranial aneurysm embolization. The management of this issue is controversial. Abciximab, a potent platelet inhibitor, has been shown to have thrombolytic effects during coronary interventions. A small number of cases have demonstrated its potential application in neuroendovascular procedures. We review the literature on the management of parent vessel thrombosis during aneurysm coil embolization and report our successful experience with the use of IV abciximab to treat parent vessel thrombus formation related to coil embolization of a basilar apex aneurysm. Case description A 45-year-old man presented to our center with an incidental basilar apex aneurysm. After being informed of the surgical and endovascular treatment options, he elected to undergo coil embolization of the aneurysm. During the procedure, acute thrombus was noted in the left P1 segment of the posterior cerebral artery. IV abciximab was administered, and an angiogram the following day showed complete dissolution of the clot. The patient had no neurologic sequelae. Conclusions IV abciximab appears to be an effective option in the management of acute parent vessel thrombus encountered during coil embolization of unruptured aneurysms. Sufficient data are lacking regarding its use in the setting of a ruptured aneurysm.