Stent-assisted Coil Embolization Research Articles

Thrombectomy and Clip Occlusion of a Giant, Stent-Coiled Basilar Bifurcation Aneurysm: 3-Dimensional Operative Video.

Giant basilar apex aneurysms are associated with significant therapeutic challenges.1-6 Multiple techniques exist to treat giant basilar apex aneurysms, including direct clipping, stent-assisted coil embolization, and proximal occlusion with bypass revascularization.7-9 Hypothermic circulatory arrest was a useful adjunct for surgical repair of these aneurysms but has been abandoned because of associated risks.10,11 Rapid ventricular pacing can achieve similar aneurysm softening with minimal risks and assist in clip occlusion. This case illustrates clip occlusion of a giant, partially thrombosed, previously stent-coiled basilar apex aneurysm in a 15-yr-old boy with progressive cranial neuropathies and sensorimotor impairment. Although a wire was placed preoperatively for ventricular pacing, it was not needed during the procedure. Patient consent was obtained. A right-sided orbitozygomatic craniotomy transcavernous approach with anterior and posterior clinoidectomies was performed. The basilar quadrification was dissected, and proximal control was obtained. After aneurysm trapping, the aneurysm was incised and thrombectomized using an ultrasonic aspirator. Back-bleeding from the aneurysm was anticipated, and ventricular pacing was ready, but back-bleeding was minimal. With the coil mass left in place, stacked, fenestrated clips were applied in a tandem fashion to occlude the aneurysm neck. Indocyanine green videoangiography confirmed occlusion of the aneurysm and patency of parent and branch arteries. The patient was at a neurological baseline after the operation, with improvement in motor skills and cognition at 3-mo follow-up. This case demonstrates the use of trans-sylvian-transcavernous exposure, rapid ventricular pacing, and thrombectomy amid previous coils and stents to clip a giant, thrombotic basilar apex aneurysm. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Outcomes following aneurysmal coil embolization with intentionally shortened low-profile visible intraluminal support stent deployment.

Among all stents available for neuroendovascular therapy, the low-profile visible intraluminal support stent bears the highest metal coverage ratio. We deployed a low-profile visible intraluminal support stent with a delivery wire or/and microcatheter system push action to shorten the low-profile visible intraluminal support stent and thus achieve a flow diversion effect. We report our single-institution experience with the use of low-profile visible intraluminal support stents for intentionally shortened deployment (shortening group) and non-shortened deployment (non-shortening group) for unruptured intracranial aneurysms. We retrospectively reviewed the medical records of 130 patients with 131 intracranial aneurysms who were treated with low-profile visible intraluminal support stent-assisted coil embolization from February 2016-January 2019. All perioperative complications were noted. Every 6 months, we re-examined the patients with cerebral angiography or magnetic resonance angiography. The outcomes of aneurysm occlusion were evaluated by the modified Raymond-Roy occlusion classification. We used the finite element method and computational fluid dynamics to investigate the hemodynamics after shortened low-profile visible intraluminal support stent deployment. Immediately after treatment, the modified Raymond-Roy occlusion classification was significantly better in the shortening group than in the non-shortening group (p<0.05). The latest angiographic outcomes showed the same tendency. Hemodynamic analysis by computational fluid dynamics suggested an adequate flow diversion effect with the use of our intentional shortening method. Stent-assisted coil embolization using this technique showed good results of a high complete occlusion rate and low complication rate. These findings suggest that shortened low-profile visible intraluminal support stent deployment yields a flow diversion effect and may lead to early intra-aneurysmal thrombus formation.

Endovascular interventions in management of renal artery aneurysm.

Renal artery aneurysm (RAA) is a rare disease. With modern non-invasive imaging modalities, the disease is being increasingly diagnosed. It is a slow-growing aneurysm with high mortality in the event of rupture; especially in pregnant females for in which case patients were treated surgically. With advances in endovascular therapy, numerous techniques have been employed to manage complex RAA in artery bifurcation, branch and segmental arteries with excellent technical and clinical success. The various recent techniques include the use of flow diverter stents, remodelling with stent-assisted coil embolization (SACE), balloon-assisted coil embolization (BACE), selective embolization with coils-sac packing, inflow occlusion and coil trapping and selective embolization with liquid embolic agents-hystroacril and onyx. A combination of stent-graft with liquid embolization and liquid with microcoil embolization has been advocated with success. The most common complication encountered is renal infarction. This is mostly without impairment of renal function and secondary to embolization. Endovascular therapy has shorter operative time, less blood loss, shorter intensive care stay, done under conscious sedation and is associated with lesser postoperative morbidity compared to surgery. Reduction in hypertension, improvement of renal function and symptoms has been seen in most studies. Endovascular management of RAA has become the management of choice even with complex anatomy and technically challenging lesions.

Treatment of recurrent and residual aneurysms with the low-profile Acandis Acclino stent: Multi-center review of 19 patients

ObjectiveTo evaluate the safety and efficacy of the low-profile Acandis Acclino microstent for embolization of recurrent and residual intracranial aneurysms. MethodsConsecutive patients treated with the Acclino for aneurysm remnants at three German neurovascular centers were enrolled. The technical success, complications, angiographic and clinical outcome were investigated. ResultsNineteen patients (median age: 53 years) with 19 aneurysm remnants (median size: 5 mm, anterior circulation: 14) were included. Initial aneurysm treatment consisted of stand-alone coiling in 14 cases, stent-assisted coiling in 4 and clipping in 1. Acclino stent-assisted coil embolization was performed technically successfully in all patients. Morbidity occurred in one patient (5.3%) due to aneurysm perforation. At the angiographic follow-up with a median follow-up duration of 21 months (range: 5–37 months), complete occlusion was obtained in 76.9%. The retreatment rate was 7.7%. ConclusionsRetreatment of aneurysm remnants with the Acclino microstent was associated with high aneurysm occlusion rates and acceptable morbidity. Further studies will be necessary to draw a definite conclusion.

Endovascular treatment of blood blister-like aneurysms of internal carotid artery: Stent-assisted coiling and pipeline flow diversion

ObjectiveTo report the stent-assisted coil embolization and flow diversion treatments of blood-blister-like aneurysms based on the theory of acute dissection of the internal carotid artery. Patients and methodsFrom July 2016 through July 2020, 27 patients presenting with subarachnoid hemorrhage (SAH) due to rupture of internal carotid artery blood blister-like aneurysms were subjected to endovascular treatment with stent-assisted coiling or Pipeline flow diversion. Clinical outcomes were evaluated using modified Rankin Scale score (mRS). ResultsA proximal stenosis caused by angiopathology adjacent to aneurysms were found on internal carotid artery angiograms in all 27 cases. The angiopathology combining with the aneurysms implement that acute dissection of the supraclinoid segment of the internal carotid artery indicated the pathogenesis of blood blister-like aneurysm formation. All aneurysms were treated successfully with alleviation of the adjacent angiopathology after stenting on angiograms. During 1–12 months, mean 3.5 months, complete aneurysm obliteration without adjacent stenosis were found in 25(92.6%) patients. Two (7.4%) cases of recanalization were retreated with complete obliteration at 1 week and 3 months after initial treatment. Clinical mRS 0 and 1 outcomes were observed in 23(85.2%) patients, mRS 2 in 3(11.1%) patients and mRS 6 in 1(3.7%) not related to aneurysm treatment during follow-up. ConclusionsAcute focal dissection of supraclinoid segment of internal carotid artery underlies the development of blood blister-like aneurysm. Stent-assisted coiling and flow diversion treatments constitute appropriate treatment based on the arterial dissection pathology.

ステント支援下コイル塞栓術で治療に成功した動脈瘤破裂による直接型内頚動脈海綿静脈洞瘻例におけるMRA元画像・再構成画像の初期診断・評価としての有用性

ステント支援下コイル塞栓術で治療に成功した動脈瘤破裂による直接型内頚動脈海綿静脈洞瘻例におけるMRA元画像・再構成画像の初期診断・評価としての有用性

3D Printed Models-A Useful Tool in Endovascular Treatment of Intracranial Aneurysms.

Many developments were made in the area of endovascular treatment of intracranial aneurysms, but this procedure also requires a good assessment of vascular anatomy prior to intervention. Seventy-six cases with brain aneurysms were selected and 1:1 scale 3D printed models were created. We asked three interventional neurosurgeons with different degrees of experience (ten years, four years, and a fourth-year resident) to review the cases using CTA (computed tomography angiogram) with MPR (multiplanar reconstructions) and VRT (volume rendering technique) and make a decision: coil embolization or stent-assisted coil embolization. After we provided them with the 3D printed models, they were asked to review their treatment plan. Statistical analysis was performed and the endovascular approach changed in 11.84% of cases for ten-year experienced neurosurgeons, 13.15% for four years experienced neurosurgeon, and 21.05% for residents. The interobserver agreement was very good between the ten years experienced interventionist and four years experienced interventionist when they analyzed the data set that included the 3D printed model. The agreement was higher between all physicians after they examined the printed model. 3D patient-specific printed models may be useful in choosing between two different endovascular techniques and also help the residents to better understand the vascular anatomy and the overall procedure.

Knowledge framework and emerging trends in intracranial aneurysm magnetic resonance angiography: a scientometric analysis from 2004 to 2020.

As magnetic resonance angiography (MRA) has been increasingly used in the follow-up of intracranial aneurysms (IAs) as a non-invasive technique, the knowledge framework and areas of research interest in intracranial aneurysms magnetic resonance angiography (IAMRA) change approximately every 10 years. However, few studies have quantitatively analyzed the published literature in this field. In the present study, we used scientometrics to survey the knowledge field, development trends, and research focus of IAMRA with the aim of providing a reference for further study. We collected articles on IAMRA published from 2004 (Jan 1, 2004) to 2020 (May 24, 2020). Web of Science Core Collection databases (WoSCCd) including the Science Citation Index Expanded were searched. An experienced staff member from the Department of Radiology at Southern Medical University, assisted in screening articles for relevant articles. We used ArcGIS (a mapping and location analytics platform) to perform geographic visualization. Excel 2016 was used to analyze the literature data, including number of publications, impact factor (IF), and publication year. CiteSpace V was used to conduct a series of literature feature clustering, including author co-citation analysis, reference co-citation analysis (RCA), and burst keywords analysis. A total of 1,272 articles on IAMRA published between 2004 and 2020 were included. Of 257 journals, American Journal of Neuroradiology (IF 2018: 3.256) published the most IAMRA articles (109 publications, 8.57%), followed by Journal of Neurosurgery (IF 2018: 4.131, 51 publications, 4.16%), and Neuroradiology (IF 2018: 2.504, 51 publications, 4.01%). Of 56 countries, the USA published the most, with 347 articles [27.28%, IF: 3.14 (average IF of all journals in the country)], followed by Japan (242 articles, 19.03%, IF: 2.38), Germany (135 articles, 10.61%, IF: 3.21), and China (101 articles, 7.94%, IF: 2.86). A total of 1387 institutions published articles, with the Mayo Clinic publishing the most (33 articles, 2.59%), followed by Shanghai Jiao Tong University (25 article, 1.97%), Seoul National University (23 articles, 1.81%), and University Medical Center Utrecht (19 articles, 1.49%). Of 399 authors, Rinkel ranked first with 19 articles, followed by Li MH (18 articles), Uchino A (15 articles), and Saito N (13 articles). Cluster RCA showed that the first cluster was "#0 growth", followed by "#1 Guglielmi detachable coils". Timeline views showed that the time span of "#0 growth" was the closest to today. The modularity value was 0.6971, and the mean silhouette value was 0.5477. According to the burst keyword analysis, "risk factors associated to rupture" was the topic with the strongest burst since 2017. Studies conducted in several countries suggested that age is inversely related to the risk of rupture, which implies the importance of MRA follow-up for patients of different age. From 2004 to 2020, the number of published IAMRA-related articles gradually increased. The USA and Western Europe lead in the field, with a concentration of cutting-edge talents and high-level scientific research institutions. A synthesis of the clustering results of RCA and burst keyword analysis indicated that unruptured IA growth, stent-assisted coil embolization, and risk factors associated to rupture were the current hotspots in IAMRA research.

Endovascular treatment of vertebral artery dissecting aneurysms : a 20-year institutional experience

BackgroundThe ideal treatment for unruptured vertebral artery dissecting aneurysms (VADAs) and ruptured dominant VADAs remains controversial. We report our experience in the management and endovascular treatment of patients with VADAs.MethodsPatients...

The Geometry of Y-Stent Configurations Used for Wide-Necked Aneurysm Treatment: Analyzing Double-Barrel Stents In Vitro Using Flat-Panel Computed Tomography

Stent-assisted coil embolization of wide-necked bifurcation aneurysms often employs a Y configuration stent. A similar stent configuration, termed kissing/double-barrel (KDB), is used often at the aortoiliac bifurcation. Studies of KDB stents in aortoiliac disease show that rates of thromboembolic complications vary with the cross-sectional geometry of the stent pair, a function of the radial crush resistive force of each stent. We assessed cross-sectional geometry of intracranial stent pairs in an invitro model of the basilar artery using flat-panel computed tomography. In a silicone model of a wide-necked basilar tip aneurysm, 6 simulated KDB stent deployment trials were performed using combinations of 5 stents (Enterprise 1, Enterprise 2, Neuroform Atlas, LVIS, LVIS Jr.). Flat-panel computed tomography reconstructions were used to assess cross-sectional stent geometry. Relative conformability, defined by ovalization and D-ratio, radial crush resistive force (predicted vs. actual), and radial mismatch fraction were compared by stent type (braided vs. laser-cut). Several distinct forms of cross-sectional stent geometry were observed. Braided stents had lower ovalization and D-ratio (P= 0.015) than laser-cut stents. The Neuroform Atlas/LVIS combination yielded the lowest radial mismatch fraction (19.7% vs. mean 44.3% ± 0.7%). Braided stents tended to have a deployed stent radius closer to the expected (nominal) diameter (i.e., higher relative crush resistive force) than laser-cut stents (measured vs. nominal diameter discrepancy+38.6% ± 21.1% vs. -10.7% ±16.1%, P= 0.14). In constant anatomy, cross-sectional geometry of the KDB stent configuration will vary depending on the design and structure of the stents employed.

Active management of the target P2Y12 reaction unit range in patients undergoing stent-assisted coil embolization for unruptured cerebral aneurysms

BackgroundPlatelet function tests have been increasingly adopted to measure patient responses to antiplatelet drugs, and to predict complications. However, no established optimal antiplatelet management for stent-assisted coil embolization (SAC) have...

Clinical efficacy of stent-assisted coil embolization for recurrent intracranial bifurcation aneurysms

Objective: To evaluate the safety and efficacy of stent-assisted coil embolization in patients with recurrent intracranial bifurcation aneurysms,after initial simple coiling or microsurgical clipping. Methods: Clinical data of 20 patients with recurrent intracranial bifurcation aneurysms who initially underwent simple coiling or surgical clipping and subsequently re-treated by stent-assisted coiling embolization at the Radiology Intervention Department of Huashan Hospital between March 2009 and November 2019 were collected and analyzed retrospectively.There were 9 males and 11 females,with a median age of 55.5 years (range:33 to 71 years),including 17 aneurysms initially treated with simple coiling and 3 treated with surgical clipping.All cases were re-treated with stent-assisted coiling,15 using a single stent and 5 employing two stents in a Y-configuration.Peri-and post-operative complications and outcomes were evaluated.Mann-Whitney U tests were performed to compare the follow-up duration between initial treatment and re-treatment.Student's t tests were used to compare the parent artery angles before re-treatment, after re-treatment and at the last follow-up. The parent artery angle was defined using the proximal main trunk and the stented branch. Results: Immediate complete occlusion (Raymond Ⅰ) was achieved in 18 aneurysms (90.0%) while 2 aneurysms (10.0%) had a residual neck (Raymond Ⅱ).The median follow-up time(M(QR)) was 8.5(16.3)months,which had no significantly different from the initial treatment follow-up duration (15.5(27.0)months)(U=157.7,P=0.25). During the follow-up period,2 aneurysms (10.0%) with immediate post-operative residual necks recanalized again,including 1 aneurysm re-treated with the Y-configuration stent.Symptomatic thromboembolic complications occurred in 6 patients,including 4 re-treated with the Y-configuration stent.No peri-operative hemorrhagic complications occurred,along with no operation-related permanent disability or death. The parent artery angle increased significantly from pre-operative(90.1±21.1)°to post-operative and the last follow-up ((115.4±28.9)° and (132.6±26.8)°);t=5.14,P<0.01;t=7.78,P<0.01). Conclusion: For recurrent intracranial bifurcation aneurysms after initial surgical clipping or simple coiling,stent assisted coil embolization is proved to be safe and can decrease recurrence rate.

Hemodynamic effects of intracranial aneurysms from stent-induced straightening of parent vessels by stent-assisted coiling embolization.

Straightening of parent vessels happens for stent-assisted coiling embolization (SACE) treatment of intracranial aneurysms. This study aims to investigate aneurysmal hemodynamic modifications caused by stent-induced vessel straightening. Stent and coil deployments of a SACE-treated distal bifurcation aneurysm by finite element method were performed first with the preoperative (not straightened, NS) and postoperative (straightened, S) vessel models respectively. Computational fluid dynamics were then performed for eight models, including (I) NS only model, (II) NS+stent model, (III) NS+coils model, (IV) NS+stent+coils model, (V) S only model, (VI) S+stent model, (VII) S+coils model, and (VIII) S+stent+coils model. Finally, changes in aneurysmal flow velocity, isovelocity surface and wall shear stress (WSS) were analyzed qualitatively and quantitatively. The flow was less in the S models than that in the corresponding NS models. Coils blocked most of the flow into the aneurysm sac in both NS models and S models and vessel straightening had more profound effect on the high aneurysmal flow volume reduction than coiling, while stenting generated adverse effect on flow reduction. Taking the NS only model as baseline (100%), the sac-averaged velocities of models II to VIII were 112%, 36%, 42%, 45%, 39%, 12%, 13%, and high flow volumes were 119%, 21%, 30%, 10%, 8%, 3%, 3%, while the sac-averaged WSSs were 106%, 37%, 44%, 41%, 35%, 17% and 24%, respectively. Stent-induced vessel straightening combined coil embolization has the best performance in hemodynamic modifications and may reduce the recurrence rate, whereas stenting may generate adverse effect on hemodynamic alterations.

Application of 3D T1-SPACE combined with 3D-TOF sequence for follow-up evaluation of stent-assisted coil embolization for intracranial aneurysm

ObjectivesTo assess 3D T1-SPACE combined with 3D-TOF sequence for follow-up evaluation of stent-assisted coil embolization for intracranial aneurysm. Materials and methodsBetween Oct 2018 and May 2019, we enrolled 25 patients with intracranial aneurysm who underwent stent-assisted coil embolization. All patients were followed up for 6 to10 months after endovascular treatment (EVT) using 3D-TOF MRA, 3D T1-SPACE and DSA to evaluate aneurysm occlusion and parent artery patency. ResultsWith regards to aneurysm occlusion, the specificity of 3D-TOF MRA was 86.9% (20/23) and the accuracy was 84% (21/25). There was no statistical significance (P ​= ​0.409) compared with the DSA. The parent artery by 3D-TOF MRA showed that there were 14 patients with grade 3, 8 patients with grade 2 and 3 patients with grade 1. However, 3D T1-SPACE showed that all 25 patients were grade 4, and were clearly displayed without metal artifacts. The comparison of the two MR techniques demonstrated that 3D T1-SPACE was superior to 3D-TOF MRA in the evaluation of parent artery (P<0.001). Conclusions3D T1-SPACE sequence provides better image quality and higher accuracy for evaluating stented parent arteries compared to TOF-MRA. This study also shows that 3D-TOF MRA has a merit to evaluate aneurysm occlusion. The combination of these two modalities can be used as an optional follow-up evaluation after EVT of intracranial aneurysms.

Is Stent-Assisted Coil Embolization for the Treatment of Ruptured Blood Blister-Like Aneurysms of the Supraclinoid Internal Carotid Artery Effective? : An Analysis of Single Institutional Experience with Pooled Data.

ObjectiveGiven the high risk of rebleeding and recurrence of blood blister-like aneurysms (BBAs), we treated ruptured BBAs of the internal carotid artery (ICA) with stent-assisted coil embolization (SAC). This study aimed to evaluate the efficacy and safety of SACs. MethodsWe retrospectively reviewed clinical and radiological data from eight patients with ruptured BBAs of the supraclinoid ICA. The modified Rankin Scale (mRS) was used to assess clinical outcomes, while radiological outcomes were evaluated on angiographs. For a pooled analysis, data from literature reporting the outcomes of ruptured BBAs treated with SAC were collected and analyzed in conjunction with our data. ResultsIn our cohort, the mean Raymond classification score was 1.57±0.53 immediately after initial endovascular treatment. There were no perioperative complications or rebleeding events during the follow-up period. The mean mRS score at patient discharge was 1.00±0.81 and improved to 0.28±0.48 by the last follow-up day. The recurrence rate was 25% with an asymptomatic presentation and successful treatment with multiple stent insertion. Pooled analysis of 76 cases of SAC revealed a complete occlusion rate immediately after treatment of 54.8%, rebleeding rate 7.94%, and recurrence rate 24.2%. Good clinical outcomes with mRS score 0–2 were observed in 89.9% by the last clinical follow-up. Total mortality rate was 7.7%. ConclusionThis treatment appears to not only minimize the hemodynamic burden on the fragile dome specific to this type of aneurysm, but also provides an opportunity for safe and effective treatment in recurrent cases.

Open-cell stent-assisted coiling for the treatment of paraclinoid aneurysms: traditional endovascular treatment is still not out of date.

Before we enter the era of flow diverter stents (FDS), the standard stent-assisted coiling technique is a well-established treatment option for routine paraclinoid aneurysms. We assess the clinical safety and efficacy of stent-assisted coiling with open-cell stent in the treatment of paraclinoid aneurysms and evaluate the association between clinical factors and follow-up aneurysm occlusion. The clinical and radiographic data of 110 consecutive patients with 122 paraclinoid aneurysms treated with open-cell stent between April 2015 and April 2019 were analyzed retrospectively at our center. We assessed the immediate and progressive occlusion rates, complications, and clinical outcome. Multivariate analysis was performed to investigate the risk factors of angiographic incomplete occlusion. Among 110 patients, stent-assisted coiling was successfully performed in all cases. Four (3.6%) thromboembolic events were reported during the procedure, which resulted in transient morbidity. Immediate angiography demonstrated complete occlusion in 64 (52.5%) aneurysms and no occlusion of ophthalmic artery. Angiographic follow-up at 6 months demonstrated an increase in the complete occlusion rate to 92.9%. No delayed in-stent stenosis was observed, and three aneurysms recurred. Clinical follow-up was completed in 102 patients (92.7%), and favorable outcomes were achieved in 101 (99%) patients at 6 months. Multivariate analysis showed that aneurysm size (p < 0.001) was associated with incomplete aneurysm occlusion at follow-up. Stent-assisted coil embolization with open-cell stents is safe and effective for the treatment of paraclinoid aneurysms and provides progressive occlusion without significant in-stent stenosis events.

Endovascular Treatment Strategy and Clinical Outcomes for Ruptured Blood Blister–Like Aneurysms of the Internal Carotid Artery Using Low-Profile Visualized Intraluminal Support Stent

It is challenging to safely treat blood blister-like aneurysms (BBAs) of the internal carotid artery. Endovascular surgery has been reported, but the optimal strategy is yet to be established. We report our endovascular treatment strategy using the Low-profile Visualized Intraluminal Support (LVIS) stent. Twelve patients with ruptured BBAs including 1 patient with 2 separate aneurysmal bulges were treated from December 2017 to January 2020. Single LVIS stent-assisted coil embolization was performed as the initial treatment. If the coil could not be placed in the aneurysm, or follow-up angiography showed persistent filling or regrowth of the aneurysm, a second LVIS stent was deployed as an overlapping stent. Clinical characteristics, treatment details, and clinical outcomes were retrospectively examined. Single stent-assisted coiling was performed in 8 patients (69%), 2 overlapping stents with coiling in 1 (8%), a single stent in 2 (15%), and 2 overlapping stents in 2 (15%). Three patients with persistent filling or regrowth of the aneurysm were re-treated with overlapping stents. Follow-up angiography confirmed complete occlusion in 12 aneurysms (92%). No re-rupture occurred. Postoperative symptomatic ischemia was confirmed in 4 patients (33%), and all 4 patients suffered severe subarachnoid hemorrhage. Modified Rankin scale was 0-2 in 8 patients (67%). LVIS stent-assisted coil embolization is effective in preventing re-rupture of BBAs. However, the morphology of the aneurysm may change within a short period, so careful angiographic follow-up is needed. Appropriate preoperative antiplatelet administration and optimal timing of the treatment may reduce the risk of postoperative ischemic complication.

Modified Balloon-in-Stent Technique for Circumferential Vertebral Artery Dissecting Aneurysm

Treatment for circumferential vertebral artery dissecting aneurysms (VADAs) remains challenging. Stent-assisted coil embolization is the most common treatment technique. However, this approach presents high rates of incomplete occlusion and recurrence, often requiring the addition of second or third stents for reconstruction. A flow diverter may achieve favorable clinical outcomes, but it cannot result in immediate aneurysm occlusion and is limited by strict antiplatelets and expensive price. We report excellent results of a 1-stage modified balloon-in-stent technique for circumferential VADA. A total of 12 patients were treated with the modified balloon-in-stent technique for VADAs. A homogeneous coil was used to fill the aneurysm sac, followed by deployment of 1 self-expandable stent and in-stent Scepter balloon angioplasty. Clinical presentations, outcomes, and imaging results were evaluated over at least 2 years of follow-up. Our 12 patients were examined during a mean follow-up period of 36.2 months (range, 2-5 years). The initial symptoms presented included subarachnoid hemorrhage (5 of 12; 41.7%), ischemia (3 of 12; 25.0%), and nonischemia (4 of 12; 33.3%). The modified BIS technique and coil embolization were successful in all patients. No technique-related complications or recanalization occurred during follow-up. We demonstrated an innovative modified BIS technique to treat circumferential VADA by using a coiling basket followed by the deployment of a self-expandable stent and in-stent Scepter balloon angioplasty. This strategy is safe, feasible, and cost effective and was not associated with recurrence or complications over at least 2 years of follow-up.

Validity of PETRA-MRA for Stent-Assisted Coil Embolization of Intracranial Aneurysms.

Pointwise encoding time reduction with radial acquisition (PETRA) using magnetic resonance angiography (MRA) is a non-enhanced MRA technique employing an ultrashort echo time, and is known to significantly reduce the magnetic susceptibility of coils and stents during post-embolization imaging. We evaluated the quality of PETRA-MRA images for use at the follow-up assessment of stent-assisted coil embolization procedures performed to treat aneurysms. A total of six aneurysm patients who were treated by stent-assisted coil embolization were included. All patients underwent PETRA-MRA, time-of-flight (TOF)-MRA performed with MAGNETOM Skyra (Siemens), and digital subtraction angiography (DSA) performed with Infinix Celeve-i INFX-8000V (Canon Medical Systems) and Allura Clarity FD20/15 (Philips). The PETRA-MRA images were compared with those from DSA and TOF-MRA to validate the aneurysm occlusion status and visually assess the blood flow within the stent. Four independent specialists graded occlusion status and flow visualization through the stent using a four-point scale, where 4 points represented excellent visualization of flow within the stent. The aneurysm was located in the internal carotid artery in two patients, the middle cerebral artery in two patients, the top of the basilar artery in one patient, and the vertebral artery-posterior inferior cerebellar artery (VA-PICA) in one patient. Three patients were treated using a Neuroform Atlas Stent system, one using an Enterprise2 VRD, one using two Neuroform Atlas stents for Y-stenting, and the remaining patient using a Neuroform Atlas and an Enterprise2 VRD for Y-stenting. With DSA, the postoperative aneurysm occlusion status was neck remnant (NR) in five cases and complete obliteration (CO) in one case. DSA and PETRA-MRA evaluations demonstrated an equal occlusion status in five of six cases, whereas DSA and TOF-MRA were equal in two of six cases. The mean visualization score for PETRA-MRA was 3.33 ± 0.82, whereas that for TOF-MRA was 2.17 ± 1.33. On the PETRA-MRA images, blood flow through the stent was well-visualized and produced an aneurysm occlusion status score comparable to DSA, especially in the three cases using the Neuroform Atlas Stent System where the visualization was scored 4 points. In the case of the VA-PICA aneurysm, for which an Enterprise2 VRD was used, PETRA-MRA images were insufficient for postoperative assessment. PETRA-MRA can provide good visualization of the blood flow within a stent and displays a clear blood signal near the coils, barring small magnetic susceptibility artifacts. Therefore, PETRA-MRA may be an effective option for follow-up imaging after stent-assisted coil embolization.

Use of Interventional Neuroradiology Devices (Solitaire AB and Cascade Net) in the Treatment of Complex Renal Aneurysms through Stent-Assisted Coil Embolisation

Introduction: The risk of rupture of true renal artery aneurysms is low but when they are bigger than 2 - 2.5 cm it increases significantly, making treatment essential. The need to use alternatives to conventional techniques in order to avoid predictable complications as coil migration is mandatory. Discussion: Routinely-used techniques in interventional neuroradiology such as flow diverters or those assisted with an occlusion balloon or stent have are suitable alternatives for complex aneurysms. Conclusion: Interventional neuroradiology devices such as the Cascade Net stent (Perflow Medical and Grupo Logsa) and Solitaire AB stent retriever (Medtronic) are valid and safe options. We describe the technique of such devices.