Treatment of intracranial aneurysms with the Enterprise stent: a multicenter registry

Initial Experience with a New Self-Expanding Open-Cell Stent System with Antithrombotic Hydrophilic Polymer Coating (pEGASUS Stent) in the Treatment of Wide-Necked Intracranial Aneurysms

PURPOSE

We report our initial experience with endovascular embolization of intracranial aneurysms using this new self-expanding open-cell stent system (pEGASUS stent system) with the antithrombogenic hydrophilic polymer coating.

MATERIALS AND METHODS

We retrospectively reviewed all patients treated with stent-assisted coiling or the Woven EndoBridge device using the pEGASUS stent system between September 2022 and June 2023. Demographic, clinical, and angiographic data were analyzed as well as short-term follow-up, including procedural complication rates and aneurysmal occlusion rates using the Raymond-Roy occlusion classification (RROC).

RESULTS

Twelve patients with 12 wide-necked intracranial aneurysms were treated with the pEGASUS stent system, including 2 acutely ruptured aneurysms embolized in an emergency setting. The treated aneurysms were located at the anterior communicating artery (25.0%), the basilar artery (50.0%), the middle cerebral artery (16.7%), and the internal carotid artery (8.3%). All stents were deployed successfully. Immediate complete aneurysmal occlusion (RROC class I) was achieved in 83.3% (10/12) and near-complete occlusion (RROC II) in 16.7% (2/12). No periprocedural complications occurred in patients treated in the elective setting. A single case of intraoperative in-stent thrombus formation occurred during the treatment of an acutely ruptured basilar aneurysm and was resolved with intravenous Tirofiban. No other periprocedural complications occurred. Eleven out of 12 patients were available for follow up (mean 7.4 months). Complete aneurysmal occlusion without in-stent stenosis (ISS) was seen in 10 patients (90.9%). One patient (9.1%) showed aneurysmal reperfusion (RROC IIIb) with asymptomatic moderate ISS.

CONCLUSION

Our initial results demonstrate that the pEGASUS stent system appears to be a safe and effective device for stent assisted embolization of wide-necked intracranial aneurysms. More data is necessary to evaluate long-term follow-up.

"Stent-within-a-Stent" technique for the endovascular treatment of giant aneurysm of basilar artery bifurcation: A case report

Stents have become very important devices in the treatment of intracranial aneurysms. Flow diverters as high metal coverage stents are developed for hemodynamic treatment of challenging intracranial aneurysms. High level of metal coverage can also be achieved by implementing regular stents telescopically one in another. We present the case of a patient successfully treated for giant aneurysm of basilar artery bifurcation by a "Stent-within-a-Stent" technique. After stent implantation, coil embolization was performed using multiple-sized platinum helical coils. Control angiography performed at the end of the procedure revealed aneurysm occlusion. After 3 years, the patient is fully neurologically recovered, without pyramidal deficit, independently active and able to work.

Comparative Analysis of the Low-Profile Acclino Stent and the Enterprise Stent for the Treatment of Unruptured Intracranial Aneurysms

OBJECTIVE

In preliminary studies, advanced intracranial stents appear to have a favorable safety profile for intracranial aneurysm treatment. This dual-center study is a head-to-head comparison of the low-profile Acandis Acclino stent (a third-generation stent) and the first- and second-generation Enterprise stent.

METHODS

Patients who underwent stent-assisted coiling with either the Enterprise or the Acclino stent for unruptured aneurysms during an 8-year period were enrolled and compared for complications, clinical outcomes, and angiographic results. Primary outcome measures were ischemic stroke rate and mid-term complete occlusion rate. Propensity score adjustment was performed to account for small differences between the groups.

RESULTS

Enterprise and Acclino stents were used in 48 cases each. The overall rate of thrombotic complications was higher in the Enterprise group than in the Acclino group (20.8% vs. 4.2%, HR: 6.6, 95%CI: 2.2-20.0, P = 0.01, adjusted P < 0.01), which translated into a higher rate of major ischemic stroke after Enterprise treatment (6.3% vs. 0%, HR: 2.1, 95%CI: 1.8-2.4, P = 0.08, adjusted P < 0.01). Mid-term and long-term angiographic follow-up showed complete occlusion rates of 83.3% and 75.0% for Enterprise and 89.2% and 75.9% for Acclino (both P > 0.05). Retreatment rates were 10.4% in the Enterprise group and 4.2% in the Acclino group (P = 0.42, adjusted P = 0.10).

CONCLUSIONS

The results indicate a favorable safety profile of the Acclino over the Enterprise, justifying the use of advanced stent systems in clinical practice. However, further comparative studies of the Acclino and other competing stent systems are needed to draw a definitive conclusion on the state of stent-assisted coiling.

A Novel Braided Stent With Customized Simulation Software for Treatment of Intracranial Aneurysms: Multicenter Prospective Trial Before Unrestricted Clinical Application

BACKGROUND AND OBJECTIVES

Planning/guidance software became important tools for physicians' presurgical optimal decision-making. However, there are no intracranial stent products with specifically associated simulation software. We report the "premarket" clinical trial of a new braided stent with a customized simulation software.

METHODS

A stent system with 3 mesh density types (16, 24, and 32 wire mesh) was designed based on computational flow dynamics technology, and a simulation software (virtual stent planner [VSP]) was developed for the optimal stent deployment planning. Stents were selected after simulation on preoperative 3D-processed angioimages, and accuracy of the VSP was evaluated.

RESULTS

Thirty-three unruptured intracranial aneurysms were successfully treated with VSP guidance. Twenty aneurysms (61%) were anterior circulation aneurysms, and 13 (39%) were posterior circulation aneurysms. The average aneurysm size was 7.1 mm, and the mean follow-up period was 19.2 months (11-39.0). There was no major recurrence or retreatment during follow-up, 2 morbidity cases, and no mortality. VSP planning presented slightly smaller stent dimensions compared with postdeployment: 24.2 vs 25.5 mm average, error -1.3 mm, and difference rate-5.46%.

CONCLUSION

Based on this result, the new stents and software guidance system were approved by the Ministry of Health and Welfare as a combined medical device. VSP provided precise deployment with minimal error compared with actual stent and can contribute to better stent deployment even for less experienced physicians.

Head and neck angiography in the pediatric population: single-center experience with indications, safety, feasibility, and technical differences among infants, childhood, and adolescents

OBJECTIVE

Pediatric patients are candidates for head and neck endovascular procedures less frequently than adults. Data on utilization, feasibility, safety, and technical details of head and neck angiography in the pediatric population are scarce.

METHODS

The authors performed a retrospective review of their center's endovascular database to identify all patients ≤ 18 years of age who underwent diagnostic or interventional catheter-based angiography of the head and neck. Procedure-related variables for identified patients were compared across infancy (birth to 2 years), childhood (> 2-11 years), and adolescence (> 11-18 years).

RESULTS

One hundred twenty-one pediatric patients who underwent 274 angiogram procedures were included in this study. Of these angiograms, 197 were diagnostic and 118 were interventional (including 41 of the diagnostic angiogram procedures that were performed concurrently with the intervention). The most common indications for diagnostic angiograms were suspected vascular malformations in 52 cases (26.4%) and aneurysms in 23 (11.7%). The rate of positive findings on diagnostic angiograms ranged from 27.3% to 80% according to the indication. Access site-related complications were observed after 2 punctures (0.7%). Procedure-related complications occurred in 3 patients (1.1%). In adolescents, the rates of general anesthesia use and sheathless access were significantly lower (each p < 0.001), and the rates of radial artery access (p < 0.001); 5-French (5F) (p = 0.01), 6F (p < 0.001), and 8F (p = 0.03) access; and closure device usage (p < 0.001) were significantly higher. In infants, the rates of ultrasound guidance, 4F access, and failure of the primary puncture site were significantly higher (each p < 0.001).

CONCLUSIONS

Head and neck angiograms in the pediatric population were feasible and safe in the authors' overall experience. Technical differences were observed across the infant, childhood, and adolescent groups, but safe outcomes were similar throughout these age ranges.

Effects of Enterprise 2 stent-assisted coil embolization for wide-necked intracranial aneurysms

BACKGROUND

This study analyzed the safety and efficacy of Enterprise 2 stent-assisted coil embolization for wide-necked intracranial aneurysms by examining stent-vessel apposition, operative complications, embolization outcomes, and clinical outcomes.

METHODS

We retrospectively reviewed the medical records of patients with wide-necked intracranial aneurysms who underwent Enterprise 2 stent-assisted coiling in our hospital from November 2018 to October 2019. Intraoperative VasoCT was performed immediately after stent release in a continuous cohort of patients to observe stent-vessel apposition. Patient demographic, clinical, and imaging data were recorded and analyzed.

RESULTS

A total of 106 wide-necked aneurysms in 106 patients were treated. Stent release was successful in all patients. Twenty-one patients were enrolled consecutively for VasoCT scanning, and incomplete stent apposition was observed in 5 (23.8%). Perioperative complications occurred in 10 patients (9.4%): cerebral infarction in 6, intraoperative coil prolapse in 1, puncture site pseudoaneurysm in 1, deep vein thrombosis at multiple sites in 1, and transient brainstem mass effect in 1. Among the 95 aneurysms with angiographic follow-up, embolization was satisfactory (Raymond-Roy classifications I and II) in 89 (93.7%). Hyperlipidemia was an independent risk factor for incomplete aneurysm occlusion. At the last clinical follow-up, seven patients had a poor clinical outcome (modified Rankin Scale score ≥ 3). Independent risk factors for poor outcomes were preoperative subarachnoid hemorrhage at presentation and cerebral infarction.

CONCLUSION

Enterprise 2 stent-assisted coiling for treatment of wide-necked intracranial aneurysms showed good safety and efficacy; however, incomplete stent apposition can still occur in vessels with a large curvature. Preoperative subarachnoid hemorrhage at presentation and cerebral infarction are the main reasons for poor clinical outcomes after stent-assisted coil embolization.

Endovascular therapy versus microsurgical clipping of unruptured wide-neck aneurysms: a prospective multicenter study with propensity score analysis

OBJECTIVE

Numerous techniques have been developed to treat wide-neck aneurysms (WNAs), each with different safety and efficacy profiles. Few studies have compared endovascular therapy (EVT) with microsurgery (MS). The authors' objective was to perform a prospective multicenter study of a WNA registry using rigorous outcome assessments and to compare EVT and MS using propensity score analysis (PSA).

METHODS

Unruptured, saccular, not previously treated WNAs were included. WNA was defined as an aneurysm with a neck width ≥ 4 mm or a dome-to-neck ratio (DTNR) < 2. The primary outcome was modified Rankin Scale (mRS) score at 1 year after treatment (good outcome was defined as mRS score 0-2), as assessed by blinded research nurses and compared with PSA. Angiographic outcome was assessed using the Raymond scale with core laboratory review (adequate occlusion was defined as Raymond scale score 1-2).

RESULTS

The analysis included 224 unruptured aneurysms in the EVT cohort (n = 140) and MS cohort (n = 84). There were no differences in baseline demographic characteristics, such as proportion of patients with good baseline mRS score (94.3% of the EVT cohort vs 94.0% of the MS cohort, p = 0.941). WNA inclusion criteria were similar between cohorts, with the most common being both neck width ≥ 4 mm and DTNR < 2 (50.7% of the EVT cohort vs 50.0% of the MS cohort, p = 0.228). More paraclinoid (32.1% vs 9.5%) and basilar tip (7.1% vs 3.6%) aneurysms were treated with EVT, whereas more middle cerebral artery (13.6% vs 42.9%) and pericallosal (1.4% vs 4.8%) aneurysms were treated with MS (p < 0.001). EVT aneurysms were slightly larger (p = 0.040), and MS aneurysms had a slightly lower mean DTNR (1.4 for the EVT cohort vs 1.3 for the MS cohort, p = 0.010). Within the EVT cohort, 9.3% of patients underwent stand-alone coiling, 17.1% balloon-assisted coiling, 34.3% stent-assisted coiling, 37.1% flow diversion, and 2.1% PulseRider-assisted coiling. Neurological morbidity secondary to a procedural complication was more common in the MS cohort (10.3% vs 1.4%, p = 0.003). One-year mRS scores were assessed for 218 patients (97.3%), and no significantly increased risk of poor clinical outcome was found for the MS cohort (OR 2.17, 95% CI 0.84-5.60, p = 0.110). In an unadjusted direct comparison, more patients in the EVT cohort achieved a good clinical outcome at 1 year (93.4% vs 84.1%, p = 0.048). Final adequate angiographic outcome was superior in the MS cohort (97.6% of the MS cohort vs 86.5% of the EVT cohort, p = 0.007).

CONCLUSIONS

Although the treatments for unruptured WNA had similar clinical outcomes according to PSA, there were fewer complications and superior clinical outcome in the EVT cohort and superior angiographic outcomes in the MS cohort according to the unadjusted analysis. These results may be considered when selecting treatment modalities for patients with unruptured WNAs.

Endovascular Therapy Versus Microsurgical Clipping of Ruptured Wide Neck Aneurysms (EVERRUN Registry): a multicenter, prospective propensity score analysis

OBJECTIVE

Randomized controlled trials have demonstrated the superiority of endovascular therapy (EVT) compared to microsurgery (MS) for ruptured aneurysms suitable for treatment or when therapy is broadly offered to all presenting aneurysms; however, wide neck aneurysms (WNAs) are a challenging subset that require more advanced techniques and warrant further investigation. Herein, the authors sought to investigate a prospective, multicenter WNA registry using rigorous outcome assessments and compare EVT and MS using propensity score analysis (PSA).

METHODS

Untreated, ruptured, saccular WNAs were included in the analysis. A WNA was defined as having a neck ≥ 4 mm or a dome/neck ratio (DNR) < 2. The primary outcome was the modified Rankin Scale (mRS) score at 1 year posttreatment, as assessed by blinded research nurses (good outcome: mRS scores 0-2) and compared using PSA.

RESULTS

The analysis included 87 ruptured aneurysms: 55 in the EVT cohort and 32 in the MS cohort. Demographics were similar in the two cohorts, including Hunt and Hess grade (p = 0.144) and modified Fisher grade (p = 0.475). WNA type inclusion criteria were similar in the two cohorts, with the most common type having a DNR < 2 (EVT 60.0% vs MS 62.5%). More anterior communicating artery aneurysms (27.3% vs 18.8%) and posterior circulation aneurysms (18.2% vs 0.0%) were treated with EVT, whereas more middle cerebral artery aneurysms were treated with MS (34.4% vs 18.2%, p = 0.025). Within the EVT cohort, 43.6% underwent stand-alone coiling, 50.9% balloon-assisted coiling, 3.6% stent-assisted coiling, and 1.8% flow diversion. The 1-year mRS score was assessed in 81 patients (93.1%), and the primary outcome demonstrated no increased risk for a poor outcome with MS compared to EVT (OR 0.43, 95% CI 0.13-1.45, p = 0.177). The durability of MS was higher, as evidenced by retreatment rates of 12.7% and 0% for EVT and MS, respectively (p = 0.04).

CONCLUSIONS

EVT and MS had similar clinical outcomes at 1 year following ruptured WNA treatment. Because of their challenging anatomy, WNAs may represent a population in which EVT's previously demonstrated superiority for ruptured aneurysm treatment is less relevant. Further investigation into the treatment of ruptured WNAs is warranted.

Evolution of the patient-first approach: a dual-trained, single-neurosurgeon experience with 2002 consecutive intracranial aneurysm treatments

OBJECTIVE

The paradigm for intracranial aneurysm (IA) treatment is shifting toward a hybrid approach involving open and endovascular techniques. The authors chronicled the evolution of IA treatment by retrospectively examining a large series of IA cases treated by a single dual-trained neurosurgeon, focusing on evolving technology relative to the choice of treatment options, perioperative morbidity, and mortality.

METHODS

The aneurysm database at the authors' institution was searched to identify consecutive patients treated with endovascular or open microsurgical approaches by one neurosurgeon during an 18-year time span. Patients were included regardless of IA rupture status, location or morphology, or treatment modality. Data collected were baseline clinical characteristics, aneurysm size, treatment modality, operative complications, in-hospital mortality, and retreatment rate.

RESULTS

A total of 1858 patients with 2002 IA treatments were included in the study. Three-hundred fifty IAs (17.5%) were ruptured. Open microsurgery was performed in 504 aneurysms (25.2%) and endovascular surgery in 1498 (74.8%). Endovascular IA treatments trended toward a growing use of flow diversion during the last 11 years. In-hospital mortality was 1.7% overall, including 7.0% in ruptured and 0.5% in unruptured cases. The overall complication rate was 3.3%, including 3.4% for microsurgical cases and 3.3% for endovascular cases. The rate of retreatment was 3.6% after clipping and 10.7% for endovascular treatment.

CONCLUSIONS

This study demonstrates complementary use of open and endovascular approaches for IA treatment. By customizing treatment to the patient, comparable rates of procedural complications, mortality, and retreatment were achieved for both endovascular and microsurgical approaches.

Long term safety and effectiveness of LVIS Jr for treatment of intracranial aneurysms- a Canadian Multicenter registry

BACKGROUND

The Low-profile Visible Intraluminal Support device (LVIS Jr) has become a commonly used intracranial stent for the treatment of intracranial aneurysms. However long-term stability and effectiveness remains to be seen. The purpose of the study was to assess the long-term efficacy, safety and durability of LVIS Jr. in a retrospective multicenter registry.

METHODS

Patients with saccular aneurysms treated at centers across Canada using LVIS Jr for intracranial aneurysms were included in this retrospective registry between the dates of January 2013 and April 2019. Self reported outcomes were collected and used to assess both perioperative and long term safety and effectiveness. Both univariate and multivariate analysis were performed.

RESULTS

Total of 196 patients (132 Women; mean age of 57.6 years) underwent endovascular aneurysm treatment with at least 1 LVIS Jr. stent. Mean aneurysm dome size was 7.4 mm, and mean neck size of 4.3 mm. Mean clinical and imaging follow up were 950 and 899 days respectively. Class I/II was achieved in 85% on long term follow up. Periprocedural morbidity and mortality was 4.6% and 2% and additional delayed morbidity and mortality was 3% and 2.5%. Aneurysm size >10 mm was independent predictor of periprocedural complication (OR 2.59, p = 0.048) while an increased dome to neck ratio >1.5 was independent predictor of increased delayed complications (OR 3.99, p = 0.02).

CONCLUSION

The LVIS Jr. intracranial stent is an effective device in the treatment of intracranial aneurysms. Satisfactory long term occlusion rates can be achieved safely with stent-assisted coil embolization.

Usefulness of Silent MRA for Evaluation of Aneurysm after Stent-Assisted Coil Embolization

OBJECTIVE

To determine the usefulness of Silent MR angiography (MRA) for evaluating intracranial aneurysms treated with stent-assisted coil embolization.

MATERIALS AND METHODS

Ninety-nine patients (101 aneurysms) treated with stent-assisted coil embolization (Neuroform atlas, 71 cases; Enterprise, 17; LVIS Jr, 9; and Solitaire AB, 4 cases) underwent time-of-flight (TOF) MRA and Silent MRA in the same session using a 3T MRI system within 24 hours of embolization. Two radiologists independently interpreted both MRA images retrospectively and rated the image quality using a 5-point Likert scale. The image quality and diagnostic accuracy of the two modalities in the detection of aneurysm occlusion were further compared based on the stent design and the site of aneurysm.

RESULTS

The average image quality scores of the Silent MRA and TOF MRA were 4.38 ± 0.83 and 2.78 ± 1.04, respectively (p < 0.001), with an almost perfect interobserver agreement. Silent MRA had a significantly higher image quality score than TOF MRA at the distal internal carotid artery (n = 57, 4.25 ± 0.91 vs. 3.05 ± 1.16, p < 0.001), middle cerebral artery (n = 21, 4.57 ± 0.75 vs. 2.19 ± 0.68, p < 0.001), anterior cerebral artery (n = 13, 4.54 ± 0.66 vs. 2.46 ± 0.66, p < 0.001), and posterior circulation artery (n = 10, 4.50 ± 0.71 vs. 2.90 ± 0.74, p = 0.013). Silent MRA had superior image quality score to TOF MRA in the stented arteries when using Neuroform atlas (4.66 ± 0.53 vs. 3.21 ± 0.84, p < 0.001), Enterprise (3.29 ± 1.59 vs. 1.59 ± 0.51, p = 0.003), LVIS Jr (4.33 ± 1.89 vs. 1.89 ± 0.78, p = 0.033), and Solitaire AB stents (4.00 ± 2.25 vs. 2.25 ± 0.96, p = 0.356). The interpretation of the status of aneurysm occlusion exhibited significantly higher sensitivity with Silent MRA than with TOF MRA when using the Neuroform Atlas stent (96.4% vs. 14.3%, respectively, p < 0.001) and LVIS Jr stent (100% vs. 20%, respectively, p = 0.046).

CONCLUSION

Silent MRA can be useful to evaluate aneurysms treated with stent-assisted coil embolization, regardless of the aneurysm location and type of stent used.

Five-Years Angiographic Follow-Up of Wide-Neck Intracranial Aneurysms Treated With LEO Plus Stent

Background: This study aimed to evaluate the angiographic and clinical outcome, with an emphasis on long-term follow-up, of the LEO Plus stent for wide-neck intracranial aneurysms treated in a single center.

Methods: We retrospectively examined a prospectively maintained database of patients treated with LEO Plus devices between January 2004 and December 2016. Data regarding patient demographics, aneurysm characteristics, and technical procedures were analyzed. Angiographic and clinical findings were recorded during the procedure and followed up over a period of at least 5 years.

Results: We identified 101 patients with 116 aneurysms. In 16 patients, the stent could not safely be placed. Thus, a total of 97 LEO Plus devices were implanted in 97 aneurysms of 85 patients. Adverse events (acute and delayed) were observed in 21.6% of cases (17/85), and most were resolved (70.6%; 12/17). Moreover, 5 years after the procedure, total morbidity and mortality were 2.3% (2/85) and 3.5% (3/85), respectively. Long-term imaging follow-up showed complete occlusions, neck remnants, and residual aneurysms in 73.1% (57/78), 14.1% (11/78), and 12.8% (10/78) of cases, respectively.

Conclusions: Long-term results of treatment of brain aneurysms with LEO stent show high rates of adequate and stable occlusion over time, with acceptable morbidity and mortality.

Longitudinal Cost Profiles of Pipeline Embolization Device Versus Stent-Assisted Coiling in Propensity-Matched Unruptured Small Anterior Circulation Aneurysms

BACKGROUND

The cost profiles of stent-assisted coiling (SAC) vs Pipeline embolization device (PED) in small unruptured anterior circulation aneurysms have not been studied.

OBJECTIVE

To compare the 2 modalities cost profiles in a propensity-matched cohort controlling for potential technical complexity confounders including size and location.

METHODS

Patients treated with either SAC or PED at our institution were identified. Following propensity-score algorithm, 46 patients, 23 in each group were matched. The procedural and follow-up costs in each group were analyzed and compared.

RESULTS

Median maximal aneurysm size in the SAC and PED cohort were 5.3 vs 5.1 mm, respectively. Costs of access guide materials were significantly higher in the SAC group (P < .01). The average implant cost was not significantly different between the SAC and PED cohorts (${\$}$13973.2 ± ${\$}$2886.2 vs ${\$}$14,760.7 ± ${\$}$3782.1, respectively; P = .43). Similarly, total procedural costs were not different (${\$}$18341.5 ± 4104 vs ${\$}$17484.3 ± 2914.1, respectively, P = .42). Although there were significantly more total follow-ups (P = .02) and longer follow-up duration (P = .01) in SAC cohort, no significant difference in follow-up costs between the 2 groups was identified (${\$}$20557 ± ${\$}$9247 vs ${\$}$18958 ± ${\$}$9171.9, P = .56). Overall cost was similar between the SAC (${\$}$38898.9 ± ${\$}$9645.5) and PED groups (${\$}$36442.4 ± ${\$}$9076) (P = .38).

CONCLUSION

In small unruptured anterior circulation aneurysms (excluding anterior communicating artery aneurysms) matched for technical complexity confounders, SAC and PED offer an overall equivalent economic cost profile. Postprocedural noninvasive imaging was more frequent in the SAC group. However, follow-up costs and total costs were not significantly different.

Ultrashort Echo Time Magnetic Resonance Angiography in Follow-up of Intracranial Aneurysms Treated With Endovascular Coiling: Comparison of Time-of-Flight, Pointwise Encoding Time Reduction With Radial Acquisition, and Contrast-Enhanced Magnetic Resonance Angiography

BACKGROUND

The optimal magnetic resonance angiography (MRA) sequence for assessing the aneurysm occlusion state or in-stent flow after endovascular coiling is not well established.

OBJECTIVE

To evaluate the diagnostic performance of pointwise encoding time reduction with radial acquisition (PETRA)-MRA in patients who underwent endovascular coiling relative to that of time-of-flight (TOF)-MRA and contrast-enhanced (CE)-MRA.

METHODS

We evaluated the aneurysm occlusion state using digital subtraction angiography (DSA) and MRA. In patients who underwent stent-assisted coiling, we estimated the visibility of in-stent flow.

RESULTS

We enrolled 189 patients with assessable TOF, PETRA, and CE-MRAs after coiling. In patients who underwent simple coiling (128 patients), PETRA showed a higher sensitivity in the detection of residual flow than TOF and CE (PETRA, 100%; CE, 83%; TOF, 80%). There were no significant differences in the height of residual flow between DSA (0.68 ± 1.45 mm) and PETRA (0.70 ± 1.50 mm; P = 1.000). In patients who underwent stent-assisted coiling (61 patients), PETRA showed the highest sensitivity (88%) in detecting residual flow (CE, 56%; TOF, 31%). Regarding in-stent flow, PETRA, CE, and TOF showed visual scores of ≥3 with frequencies of 96.7%, 85.2%, and 37.7%, respectively. Relative signal-to-noise ratio of PETRA (0.62 ± 0.18) was significantly higher than that of CE (0.56 ± 0.12) and TOF (0.39 ± 0.12; P < .001 for both).

CONCLUSION

PETRA-MRA showed excellent diagnostic performance in terms of residual flow detection and in-stent flow assessment. PETRA could be a versatile alternative sequence for following up patients with coiled aneurysm.

Y-stent assisted coiling of ruptured wide neck intracranial aneurysm in the acute phase

BACKGROUND

The objective of the present study is to analyze the outcomes of patients with subarachnoid hemorrhage (SAH) in the acute phase after treatment with Y-stent-assisted coiling (YSAC) embolization.

METHODS

This retrospective study assessed of 30 patients with acutely ruptured wide-neck aneurysms following YSAC treatment between April 2013 and October 2019. The demographic data, aneurysm occlusion grade, procedural and periprocedural complications, and clinical outcomes were assessed.

RESULTS

The procedure was completed in 30 cases (90.1%) and technical failure occurred in 3 cases (9.1%). Immediate control angiography revealed that total occlusion Raymond-Ray Class 1 (RR1) was achieved in 21 (70%), neck filling (RR2) in eight (26.6%) and sac filling (RR1) in one (3.3%) aneurysm. Upon angiographic follow-up, RR1 occlusion was observed in 15 (71.4%) patients, RR2 in three (14.3%) patients and RR3 in three (14.3%) patients. In-stent thrombus developed in five (16.6%) patients; procedural ischemic events were observed in four (13.3%) patients; and two (6.6%) patients were symptomatic. A periprocedural asymptomatic intracranial hemorrhage was detected in two patients. At discharge, 17 (56.6%) patients were in good clinical condition, six (20%) were in a severe disability condition, and seven (23.3%) patients had died. At the final follow-up visit (mean: 18.9 months), 16 (76,2%) of 21 patients were in a good clinical condition and five (23.8%) had severe disabilities.

CONCLUSIONS

Y-stent assisted coiling in might be a feasible and promising option for treatment in acute phase in selected wide-necked ruptured intracranial aneurysms.

Risk Factors of Angiographic Recurrence After Endovascular Coil Embolization of Intracranial Saccular Aneurysms: A Retrospective Study Using a Multicenter Database

Background: Endovascular therapy of intracranial aneurysms has a high recurrence rate. This study aimed to evaluate the risk factors of recurrence after endovascular coil embolization of intracranial aneurysms.

Methods: From January 2014 to May 2015, 504 patients with 558 intracranial aneurysms who were treated by endovascular therapy were recruited from four high-volume centers. We used multivariate Cox proportional hazard regression to evaluate the risk factors associated with the angiographic recurrence of intracranial saccular aneurysms after endovascular coil embolization.

Results: Angiographic follow-up was available for 504 patients (558 aneurysms), with a mean duration of 11.42 months. Of the 558 aneurysms, 57 (10.2%) aneurysms showed recurrence. Aneurysm size (p = 0.028), therapy (non-stent assisted coiling or stent-assisted coiling) (p = 0.008), the Raymond scale (p = 0.040), aneurysm rupture status (p < 0.001), and packing density (p < 0.001) showed significant associations with angiographic follow-up outcome. A low packing density was independently associated with aneurysmal recurrence after multivariate Cox proportional hazard regression analysis (p < 0.001).

Conclusion: Endovascular treatment is effective for these lesions. Multiple factors could attribute to the aneurysmal recurrence after endovascular coil embolization. The low packing density is the independent risk factor for aneurysmal recurrence. These findings should be verified by larger multicenter and multi-population studies.

Initial Experience of Coil Embolization for Unruptured Intracranial Aneurysm Combined with Neuroform Atlas and Undersized Flexible Coils

Objective

Intraprocedural rupture (IPR) is a rare complication that can occur during endovascular treatment (EVT) of unruptured intracranial aneurysms (UIAs). However, it leads to high morbidity and mortality rates. Others have showed that coil flexibility is a risk factor for IPR. Neuroform Atlas (NA) stents can be deployed with 0.0165-inch microcatheters to enable stent assisted coiling (SAC) with a high likelihood. Undersized flexible coils can be inserted initially during SAC. This study aimed to determine whether SAC using NA and highly flexible coils for UIAs can be conducted without IPR.

Methods

We retrospectively analyzed nine consecutive patients (mean age, 73.2 years; female, n = 6) who underwent SAC for UIAs combined with NA stents and undersized flexible coils between January 2017 and December 2019. Two aneurysms were located at the internal carotid artery (ICA), and one each was located at the ICA-posterior communicating, anterior communicating, middle cerebral, vertebral, vertebra-posterior inferior cerebral and basilar arteries. The mean size of the aneurysms was 4.6 (range, 3.1-8.6) mm. SAC proceeded using the jailing technique. All coils were selected from among the most flexible coils available. We retrospectively assessed technical success rates, aneurysm occlusion at final digital subtraction angiography (DSA), volume embolization ratios (VERs), rates of IPR and symptomatic stroke within 30 days, angiographic findings of aneurysm occlusion at 3 months post-procedure and late adverse events (frequency of aneurysmal rupture, ipsilateral ischemic stroke, and retreated targeted aneurysms).

Results

The technical success rate was 100%. Complete occlusion (CO) was immediate in 8 (89%) patients and a neck remnant persisted in 1 (11%). No IPR or symptomatic stroke developed within 30 days. During a mean follow-up period of 11.8 months, CO persisted in 8 (89%) patients. No late adverse events occurred.

Conclusion

The early clinical and angiographic findings of SAC for UIAs combined with an NA stent and undersized flexible coils were favorable for this series.

Comparison of stent-assisted and no-stent coil embolization for safety and effectiveness in the treatment of ruptured intracranial aneurysms

OBJECTIVE

The safety of the stent-assisted coil embolization (SAC) technique for acutely ruptured aneurysms has not been established yet. SAC is believed to be associated with a high risk of thromboembolic and hemorrhagic complications in acute subarachnoid hemorrhage (SAH). The aim of this study was to evaluate the safety and efficacy of the SAC technique in the setting of acutely ruptured aneurysm.

METHODS

A total of 102 patients who received endovascular treatment for acute SAH between January 2011 and December 2017 were enrolled. The SAC technique was performed in 38 of these patients, whereas the no-stent coil embolization (NSC) technique was performed in 64. The safety and efficacy of the SAC technique in acute SAH was evaluated as compared with the NSC technique by retrospective analysis of radiological and clinical outcomes.

RESULTS

There were no significant differences in clinical or angiographic outcomes between the SAC and NSC techniques in patients with acute SAH. The rate of ventriculostomy-related hemorrhagic complications was higher in the SAC group than that in the NSC group (63.6% vs 12.5%; OR 12.25, 95% CI 1.78-83.94, p = 0.01). However, all these complications were asymptomatic and so small that they were only able to be diagnosed with imaging.

CONCLUSIONS

Ruptured wide-necked aneurysms could be effectively and safely treated with the SAC technique, which showed clinical and angiographic outcomes similar to those of the NSC technique. Hence, the SAC technique with dual-antiplatelet drugs may be a viable option even in acute SAH.

Early Multicenter Experience With the Neuroform Atlas Stent: Feasibility, Safety, and Efficacy

BACKGROUND

The Neuroform Atlas stent™ (by Stryker, Fremont, California) represents the most recent widely available upgrade to intracranial stenting, providing a laser cut open cell stent with a diameter of 3.0 to 4.5 mm that is delivered through an 0.017-inch microcatheter.

OBJECTIVE

To report our initial multicenter experience of the safety, efficacy, and feasibility of the Atlas stent used for treating aneurysms, as well as one case of intracranial stenosis and one carotid artery dissection as well as other pathologies.

METHODS

A retrospective multicenter study of subjects treated with Atlas stent during the period 2018 to 2019.

RESULTS

The total number of patients included in our analysis was 71 patients. The stent was utilized to treat 69 aneurysm cases. Of the aneurysms, 36% presented with acute rupture and 56% of the ruptured aneurysms were high grade. Mean aneurysm dimension was 7 mm with an average neck width of 4.1 mm. Around 30% had received prior treatment. Telescoping or Y-stent was used in 16% of cases. We did not observe any symptomatic major complications in our series. Asymptomatic major complications were seen in 7 patients (10.1%); technical complications occurred in 4.3%. Immediate modified Raymond-Roy-occlusion-outcome class I/II was observed in 87%, and this increased to 97.7% at latest follow-up, which was at 4 mo; 91.8% of patients achieved favorable clinical outcome, and mortality rate was 1.4%.

CONCLUSION

Our series demonstrates the safety, feasibility, and efficacy of the Atlas stent. The low complication rate and the high obliteration rate managing complex aneurysms, even in an acute ruptured setting, are notable.

Safety of stent-assisted coiling for the treatment of wide-necked ruptured aneurysm: A systematic literature review and meta-analysis of prevalence

BACKGROUND

Stent-assisted coil embolization of ruptured wide-necked aneurysms is a controversial treatment modality due to concerns on the peri-procedural safety of anti-platelet therapy in the setting of acute subarachnoid hemorrhage. Our aim was to systematically review the literature on stent-assisted coil embolization of acutely ruptured wide-neck aneurysms to calculate the pooled prevalence of clinical outcome, thromboembolic and hemorrhagic complication rates and overall mortality.

METHODS

We searched PubMed and Google Scholar for articles published between 2009 and 2019 and stratified selected articles based on risk of publication bias. Data on thromboembolic and hemorrhagic complications, clinical outcomes and mortality rates were analyzed using quality-effects model and double arcsine transformation.

RESULTS

24 articles were included featuring a total of 1582 patients. Thromboembolic and hemorrhagic complication rates were witnessed in 9.1% [95% CI: 6.0% - 12.7%; I² = 72.8%] and 8.7% [95% CI: 5.4 - 12.6%; I² = 77.2%] of patients, respectively. 245 patients received external ventricular drains, of which 33 (13.5%) had EVD-related hemorrhages. Total complication rate was 20.8% [95% CI: 14.2 - 28.1%; I² = 87.0%]. 57% of aneurysms were completely occluded and a favorable clinical outcome was reported in 74.7% [95% CI: 66.4 - 82.2%; I² = 86.0] of patients. Overall mortality rate came at 7.8% [95% CI: 4.8 - 11.6%; I² = 76.9%].

CONCLUSION

Stent-assisted coiling of ruptured intracranial aneurysm is a technically feasible procedure with controlled thromboembolic complication rate but may be associated with higher hemorrhagic and total complication rates compared to coiling alone. While stent-assisted coiling of ruptured wide-necked aneurysm seems to yield a lower rate of favorable clinical outcome, overall mortality is comparable to that of endovascular coiling alone.

A neurovascular high-frequency optical coherence tomography system enables in situ cerebrovascular volumetric microscopy

Intravascular imaging has emerged as a valuable tool for the treatment of coronary and peripheral artery disease; however, no solution is available for safe and reliable use in the tortuous vascular anatomy of the brain. Endovascular treatment of stroke is delivered under image guidance with insufficient resolution to adequately assess underlying arterial pathology and therapeutic devices. High-resolution imaging, enabling surgeons to visualize cerebral arteries' microstructure and micron-level features of neurovascular devices, would have a profound impact in the research, diagnosis, and treatment of cerebrovascular diseases. Here, we present a neurovascular high-frequency optical coherence tomography (HF-OCT) system, including an imaging console and an endoscopic probe designed to rapidly acquire volumetric microscopy data at a resolution approaching 10 microns in tortuous cerebrovascular anatomies. Using a combination of in vitro, ex vivo, and in vivo models, the feasibility of HF-OCT for cerebrovascular imaging was demonstrated.

Recent advances in stent-assisted coiling of cerebral aneurysms

INTRODUCTION

Stent-assisted coiling (SAC) of intracranial aneurysms paved the way for endovascular coiling of wide-neck and bifurcation aneurysms, improving rates of aneurysm obliteration and recurrence. In this review, we provide a comprehensive review of the most recent advances related to stent-assisted coiling of intracranial aneurysm.

AREAS COVERED

The authors have made an attempt to cover the inception, applications, and limitations of SAC of intracranial aneurysms. Special focus is given to 1) the current and recently introduced SAC techniques, 2) most recent advances in device technology, and 3) outcome data for the discussed techniques and devices. The authors also discuss the potential future direction of SAC.

EXPERT OPINION

technical refinements in the field of SAC should continue to focus on device development and addressing the limitations of SAC, namely aneurysm recurrence and need of antiplatelet agents. Although the recurrence rate of SAC has not been shown to be inferior to flow diverters, the use of intrasaccular and intravascular flow diverters are likely to expand in the future at the expense of SAC.

Early experience treating intracranial aneurysms using Accero: a novel, fully visible, low profile braided stent with platinum-nitinol composite wire technology

BACKGROUND

Accero is an innovative, fully visible, self-expanding braided stent with platinum-nitinol composite wire technology, produced by Acandis.

OBJECTIVE

To assess the technical success and safety of this new stent by evaluating the intraprocedural behavior and complication rate, and the short-term follow-up results.

METHODS

Forty-one consecutive patients suitable for stent-assisted coiling were selected for the use of Accero in an 11-month period. Clinical, procedural, and angiographic data, as well as 30-day morbidity, were recorded. The angiographic results, clinical follow-up at 30 days, and early imaging follow-up at 3 or 6 months were analyzed, when available.

RESULTS

Forty-one aneurysms were treated with stent-assisted coiling. All cases were elective, of which 19 were previously untreated aneurysms and 22 were recurrent aneurysms. Aneurysm location was anterior communicating artery complex (16), basilar (12 cases), middle cerebral artery bifurcation (9 cases), and internal cerebral artery (4 cases). The stent was successfully deployed and aneurysm occlusion with coils achieved in 100% of our patients. One case of on table in-stent thrombosis occurred, which resolved after administration of glycoprotein IIB/IIIA inhibitor, with no clinical consequence, and one case of postoperative hematoma at the arteriotomy site, which was managed conservatively. On early follow-up, available for 37 patients, the complete occlusion rate was 76%, with only two recurrences needing further treatment. Satisfactory aneurysm occlusion was therefore achieved in 95% of cases.

CONCLUSION

Stent-assisted coiling with the Accero braided stent proved safe and effective.

Double stent assisted coiling of intracranial bifurcation aneurysms in Y and X configurations with the Neuroform ATLAS stent: immediate and mid term angiographic and clinical follow-up

Purpose

Self-expandable stents have broadened the spectrum of endovascular treatment of intracranial aneurysms. However, procedures involving double stenting in Y/X configurations carry a relatively high risk of procedural complications. The Neuroform ATLAS, the evolution of Neuroform EZ, is a nitinol self-expanding hybrid/open cell stent which can be delivered through a low profile 0.017 inch catheter. We present our experience in the treatment of intracranial aneurysms with this stent in Y and X configurations.

Materials and methods

We prospectively maintained a database from consecutive patients who underwent double stent assisted coiling with the Neuroform ATLAS, from July 2015 to February 2019. Clinical and angiographic results were analyzed.

Results

55 patients harboring 55 bifurcation aneurysms were treated with double stenting: 52 ‘Y’ configurations, 3 ‘X’ configurations. Deployment was successful in all cases. Post-treatment control angiography showed complete occlusion in 33 cases (60%), neck remnant in 8 cases (14.5%), and incomplete occlusion in 14 cases (25.4%). The overall symptomatic periprocedural complication rate was 12.7%. 38 aneurysms underwent follow-up (69%, mean duration 16 months): 33 aneurysms (87%) were completely occluded, 3 aneurysms (8%) had a neck remnant, and 2 aneurysms (5%) were incompletely occluded.

Conclusion

The Neuroform ATLAS is an effective device for treatment of bifurcation aneurysms, allowing good conformability, a high level of navigability, and easy mesh crossing to perform Y/X stenting procedures. The rate of procedural complications remains non-negligible, and an indication for a double stenting procedure should be carefully discussed in a multidisciplinary meeting.

Comparison of endovascular treatment for middle cerebral artery aneurysm with a low-profile visualized intraluminal support stent or pipeline embolization device

The aim of the present study was to evaluate the safety and effectiveness of low-profile visualized intraluminal support (LVIS) stent and the pipeline embolization device (PED) for middle cerebral artery (MCA) aneurysm treatment. Data of patients with MCA aneurysms who received endovascular treatment with LVIS stent or PED added to the hospital's database between August 2016 and March 2018 were retrospectively collected, and the clinical results and angiographic outcomes were evaluated. A total of 43 patients were included in the study, of whom 23 received LVIS stents and 20 received PED. The rate of complete occlusion was similar in the two groups at 6 months post-treatment (90.9 vs. 88.9%; P=0.832). Peri-operative complications were more frequent in the PED group; however, the LVIS group had more ischemic symptoms during the long-term follow-up. A larger aneurysm size (P=0.032) was associated with recanalization in the two groups. In conclusion, the LVIS stent and PED had acceptable rates of complete occlusion and aneurysm size was an independent predictor for recanalization. LVIS is more effective during the peri-operative period, while PED appears to have higher long-term safety.

The pCONUS HPC: 30-Day and 180-Day In Vivo Biocompatibility Results

Background

Endovascular stents are commonly used during neurointerventional procedures; however, the concomitant use of dual anti-platelet treatment (DAPT) can limit their use. There is a need to develop stent coatings that mitigate requirement for DAPT.

Methods

The hydrophilic polymer coating is a novel glycan-based multilayer polymer that inhibits platelet adhesion. After Institutional Animal Care and Use Committee approval, 18 New Zealand white rabbits (mean weight 4.02 ± 0.51 kg) were commenced on DAPT (ASA 10 mg/kg/day and clopidogrel 10 mg/kg/day). A bare nitinol pCONUS and coated pCONUS HPC were implanted into the common carotid arteries of each rabbit. Histological examinations were performed at 30 days (n = 9) and 180 days (n = 8) to assess the acute and chronic inflammatory reactions to the pCONUS HPC. Wilcoxon/Kruskal–Wallis and ANOVA were used with p value < 0.05 considered as significant.

Results

There is no statistically significant difference in inflammation within the intima/media or adventitia at 30 days (p = 0.3901 and p = 1, respectively) or at 180 days (p = 0.144 and p = 1, respectively) between pCONUS and pCONUS HPC cohorts. There is no significant difference in the presence of granulomas or giant cells between the cohorts at either 30 days (p = 1 and p = 0.8363) or 180 days (p = 1.00 and p = 0.149). At 30 days and 180 days, there was near-complete endothelialisation of the stent struts and no significant difference between the pCONUS or pCONUS HPC (p = 0.7832 and p = 0.334, respectively).

Conclusion

pCONUS HPC stents do not elicit an acute or chronic inflammatory response in vivo with no significant difference in the tissue response to bare nitinol pCONUS stents or pCONUS HPC stents.

Endovascular Metal Devices for the Treatment of Cerebrovascular Diseases

Cerebrovascular disease involves various medical disorders that obstruct brain blood vessels or deteriorate cerebral circulation, resulting in ischemic or hemorrhagic stroke. Nowadays, platinum coils with or without biological modification have become routine embolization devices to reduce the risk of cerebral aneurysm bleeding. Additionally, many intracranial stents, flow diverters, and stent retrievers have been invented with uniquely designed structures. To accelerate the translation of these devices into clinical usage, an in-depth understanding of the mechanical and material performance of these metal-based devices is critical. However, considering the more distal location and tortuous anatomic characteristics of cerebral arteries, present devices still risk failing to arrive at target lesions. Consequently, more flexible endovascular devices and novel designs are under urgent demand to overcome the deficiencies of existing devices. Herein, the pros and cons of the current structural designs are discussed when these devices are applied to the treatment of diseases ranging broadly from hemorrhages to ischemic strokes, in order to encourage further development of such kind of devices and investigation of their use in the clinic. Moreover, novel biodegradable materials and drug elution techniques, and the design, safety, and efficacy of personalized devices for further clinical applications in cerebral vasculature are discussed.

Selective Temporary Stent-Assisted Coil Embolization for Intracranial Wide-Necked Small Aneurysms Using Solitaire AB Retrievable Stent

Objective

Stent-assisted coil embolization of intracranial wide-necked aneurysm requires long-term postoperative antiplatelet therapy to prevent in-stent thrombosis. This study aimed to demonstrate results of temporary stent placement for coiling wide necked small intracranial aneurysms, which eliminated need for antiplatelet agents, and to discuss its feasibility and safety.

Methods

Data of 156 patients who underwent stent-assisted coil embolization between 2011 and 2014 were retrospectively analyzed. Thirteen cases of temporary stent-assisted coil embolization were included, and their clinical and radiological results were evaluated.

Results

The aneurysms treated were all unruptured except one case. All of them had wide neck with mean dome-to-neck ratio of 0.96 and were small-sized aneurysms with mean maximal diameter of 4.2 mm. There was no technical failure in retrieval of stent after completion of embolization of the target aneurysm. Immediate angiography revealed 11 complete and two partial embolization (one residual neck and one residual aneurysm). Two cases encountered thrombosis complication, and they were managed without neurological sequelae. The mean follow-up period was 43 months, angiographic follow-up revealed two cases with minor recurrence, and clinical outcome was good with modified Rankin scale score of 0.

Conclusion

Temporary stent-assisted coil embolization of small wide-necked intracranial aneurysm using fully retrievable stent appears safe and effective. Further application and evaluation of this technique in more cases with larger size aneurysm is warranted.

The use of flow diverters to treat small (≤5 mm) ruptured, saccular aneurysms

Background:

There is limited published literature on the use of flow diverting stents (FDS) to treat ruptured intracranial aneurysms in the acute stage. We present our experience of using FDS to treat small (≤5 mm) ruptured aneurysms.

Methods:

We retrospectively identified all patients with ≤5 mm ruptured aneurysms treated exclusively with FDS between February 2009 and February 2016. We recorded demographic data, the Hunt and Hess score, aneurysm location and size, therapeutic intervention, immediate angiographic and clinical result, and clinical and radiological follow-up information.

Results:

We identified seven patients (four females) with average age 59.8 ± 10 years (range 48–75). The average aneurysm fundus size was 2.7 ± 0.76 mm (range 1–4 mm). The average time from ictus to treatment was 6.3 days (range 1–14 days) and there were no cases of repeat rupture prior to treatment or intraoperative rupture. Angiographic follow-up was available in five patients. At initial follow-up, aneurysms (100%) were completely occluded raymond roy classification 1 (RRC 1). None of the aneurysms re-ruptured following treatment. Clinically, six patients were discharged with good functional outcome modified Rankin Score (mRS ≤2). There were no mortalities.

Conclusion:

The use of FDS to treat small, ruptured, saccular aneurysms is feasible; however, the use of FDS should not be considered first-line treatment. Further studies are required to determine the safety and efficacy of the use of FDS in the acute situation.

The safety and effectiveness of the LVIS stent system for the treatment of wide-necked cerebral aneurysms: final results of the pivotal US LVIS trial

Introduction

The LVIS stent system (LVIS and LVIS Junior) is a self-expanding, retrievable, microstent system indicated for the treatment of wide-necked cerebral aneurysms (WNAs). The present pivotal study was performed to evaluate the safety and effectiveness of this device.

Methods

The US LVIS pivotal trial was a prospective, multicenter, single-arm, interventional study conducted at 21 US centers. The study enrolled 153 adults with WNAs of the anterior and posterior circulations. The study was conducted under good clinical practices and included independent adjudication of all adverse events. The primary effectiveness endpoint was defined as successful aneurysm treatment with the LVIS System as evidenced by complete (100%) aneurysm occlusion at 12 months on conventional angiography without retreatment and without significant (≥50%) stenosis of the treated artery at 12 months as determined by an independent core laboratory. The primary safety endpoint was defined as the rate of stroke or death within 30 days, or ipsilateral stroke or neurologic death with 12 months.

Results

One hundred and fifty-three patients enrolled at 21 investigational sites underwent attempted LVIS-assisted coil embolization. The mean age was 58.3±10.5 years and the majority of the participants (110/153, 71.9%) were female. Fifty-seven aneurysms (57/153, 37.3%) arose from the anterior cerebral artery, 43 (43/153, 28.1%) from the internal carotid artery, 17 (17/153, 11.1%) from the middle cerebral artery, 27 (27/153, 17.6%) from the basilar artery, six (6/153,3.9 %) from the PCA, and two from the vertebral artery. A single aneurysm arose from the superior cerebellar artery. The mean aneurysm dome height was 6.0±2.2 mm and mean width 5.5±2.3 mm. Mean neck width was 4.2±1.4 mm. A total of 22 participants presented for re-treatment of a previously ruptured (>30 days prior to treatment) target aneurysm. The primary effectiveness endpoint was observed in 70.6% (108/153) in the intent to treat population (ITT). Of the evaluable participants with follow-up 12-month angiography, 79.1 % (110/139) demonstrated complete occlusion– 92.1% (128/139) in this population demonstrated ≥95% occlusion and 95% demonstrated ≥90% occlusion (132/139). Eight participants (5.2%, 8/153) had at least one primary safety event in the ITT population.

Conclusion

The LVIS stent system allows safe and highly effective coil embolization of WNAs.

Clinical registration number

NCT01793792.

The use of flow diverters to treat aneurysms of the posterior inferior cerebellar artery: Report of three cases

Objective The objective of this study was to report our experience on the use of flow diverting stents placed within the posterior inferior cerebellar artery (PICA) as a treatment option for aneurysms of the PICA. Methods Three patients with aneurysms of the PICA, both ruptured and unruptured, underwent treatment of their aneurysms with placement of a single flow diverter in the PICA across the neck of the aneurysm. Adjunctive techniques such as coiling were not used. We present the angiographic and clinical follow-up data. Results The procedure was a technical success in all cases and there were no intraoperative complications. Follow-up data were available for two patients and this showed complete occlusion of the aneurysm with the PICA remaining patent. There was no evidence, either clinical or radiological, of medullary or pontine infarction. One patient died during the follow-up period from an unrelated medical illness (community acquired pneumonia). Conclusion Flow diverters can be successfully placed within the PICA to treat both ruptured and unruptured aneurysms, and they represent an alternative treatment option to endovascular coiling or microscopic neurosurgery.

The Neuroform Atlas stent to assist coil embolization of intracranial aneurysms: a multicentre experience

Objective

To assess the clinical safety and efficacy of the Atlas microstent in stent-assisted coil embolization of wide-necked intracranial aneurysms.

Methods

Single-center observational study in 36 patients (24 female, 12 male, mean age 56 years) with 37 aneurysms for the endovascular treatment of wide-necked aneurysms. After giving informed consent, patients were included according to the following criteria: aneurysm dome-to-neck ratio <2 or neck diameter >4 mm, and a parent vessel diameter of ≤4.5 mm. Primary endpoint for clinical safety was absence of death, absence of major or minor stroke, and absence of transient ischemic attack. Primary endpoint for treatment efficacy was complete angiographic occlusion according to the Raymond-Roy occlusion classification (RROC) immediately after the procedure.

Results

In 36/37 (97%) cases, the primary endpoint of safety was reached, one patient had a transitory ischemic attack which completely resolved until discharge. In 31/37 (84%) cases, complete occlusion (RROC 1) was reached, and in 6/36 (17%), a residual neck remained (RROC 2). A sequential approach (first stent, then coiling through the same catheter) was used in 21 cases; the other 16 were treated with the jailing technique. Deployment was technically successful in all cases. Follow-up at a median of 6.1 months was available for 29/37 (78%) aneurysms and showed complete occlusion in 27/29 aneurysms (93%) and a neck remnant in 2 cases (7%).

Conclusion

Deployment of the Neuroform Atlas microstent is a safe and effective method for the treatment of intracranial wide-necked aneurysms.

Patterns, Predictors, and Outcomes of Postprocedure Delayed Hemorrhage Following Flow Diversion for Intracranial Aneurysm Treatment

OBJECTIVE

To evaluate patterns, predictors, and outcomes of postprocedure delayed hemorrhage (PPDH) following flow diversion therapy for intracranial aneurysm treatment.

METHODS

From 2012 to 2016, 50 patients with 52 aneurysms were treated with the Pipeline embolization device. Device placement was performed as a standalone therapy or with adjunctive coil embolization. Patients underwent dual antiplatelet therapy for 6 months after treatment. Medical comorbidities; aneurysm traits; and treatment factors, including platelet function testing, were studied. Statistical analysis was performed using cross-tabulation.

RESULTS

Six PPDHs (12%) occurred 2-16 days (mean 6.8 days) after Pipeline placement, manifesting as 1 of 2 distinct patterns: convexity subarachnoid hemorrhage (cSAH) (n = 4) or lobar intraparenchymal hemorrhage (IPH) (n = 2). All PPDHs occurred ipsilateral to the device; 1 IPH occurred ipsilateral but in a different arterial territory. PPDH occurred in both treated anterior communicating artery aneurysms. Cases of PPDH demonstrated on average lower P2Y12 reaction unit values at the time of treatment. Platelet function testing at the time of hemorrhage was consistently hypertherapeutic. Patients with cSAH had only minimal worsening of modified Rankin Scale score at the time of discharge, whereas the 2 patients with IPH experienced significant deterioration.

CONCLUSIONS

PPDH is a poorly understood complication following flow diversion therapy that can result in significant morbidity. In our experience, nonaneurysmal cSAH does not result in poor clinical outcomes, whereas IPH leads to long-term deficits or death. As previously suggested, there appears to be a correlation between low P2Y12 reaction unit values and PPDH.

Quantitative Analysis of Conebeam CT for Delineating Stents in Stent-Assisted Coil Embolization

BACKGROUND AND PURPOSE

Innovative techniques and device-related advances have improved the outcomes of neuroendovascular treatment. 3D imaging has previously used 2 × 2 binning, but 1 × 1 binning has recently been made available. The aim of this study was to evaluate the quantitative ability of conebeam CT for stent delineation and to investigate its effectiveness in the clinical environment.

MATERIALS AND METHODS

Four acquisition groups of 3D MIP images acquired using conebeam CT with varying conditions (acquisition time, 10 or 20 seconds and binning, 1 × 1 or 2 × 2) were compared. Two methods of analysis were performed, a phantom study and an analysis of 28 randomly selected patients. The phantom study assessed the contrast-to-noise ratio and full width at half maximum values in conebeam CT images of intracranial stent struts. In the clinical subjects, we assessed contrast-to-noise ratio, full width at half maximum, and dose-area product.

RESULTS

In the phantom study, the contrast-to-noise ratio was not considerably different between 10- and 20-second acquisition times at equivalent binning settings. Additionally, the contrast-to-noise ratio at equivalent acquisition times did not differ considerably by binning setting. For the full width at half maximum results, equivalent acquisition times differed significantly by binning setting. In the clinical analyses, the 10-second/1 × 1 group (versus 20 second/2 × 2) showed a higher contrast-to-noise ratio (P < .05) and a dose-area product reduced by approximately 70% (P < .05), but the difference in full width at half maximum was not significant (P = .20).

CONCLUSIONS

For stent-assisted coil embolization, quantitative assessment of conebeam CT showed that 10 second/1 × 1 was equivalent to 20 second/2 × 2 for imaging deployed intracranial stents. Furthermore, the 10-second/1 × 1 settings resulted in a much smaller DAP.

LVIS Blue as a low porosity stent and coil adjuvant

Introduction

The LVIS Blue is an FDA-approved stent with 28% metallic coverage that is indicated for use in conjunction with coil embolization for the treatment of intracranial aneurysms. Given a porosity similar to approved flow diverters and higher than currently available intracranial stents, we sought to evaluate the effectiveness of this device for the treatment of intracranial aneurysms.

Methods

We performed an observational single-center study to evaluate initial occlusion and occlusion at 6-month follow-up for patients treated with the LVIS Blue in conjunction with coil embolization at our institution using the modified Raymond–Roy classification (mRRC), where mRRC 1 indicates complete embolization, mRRC 2 persistent opacification of the aneurysm neck, mRRC 3a filling of the aneurysm dome within coil interstices, and mRRC 3b filling of the aneurysm dome.

Results

Sixteen aneurysms were treated with the LVIS Blue device in conjunction with coil embolization with 6-month angiographic follow-up. Aneurysms were treated throughout the intracranial circulation: five proximal internal carotid artery (ICA) (ophthalmic or communicating segments), two superior cerebellar artery, two ICA terminus, two anterior communicating artery, two distal middle cerebral artery, one posterior inferior cerebellar artery, and two basilar tip aneurysms. Post-procedurally, there was one mRRC 1 closure, five mRRC 2 closures, and 10 mRRC 3a or 3b occlusion. At follow-up, all the mRRC 1 and mRRC 3a closures, 85% of the mRRC 3b closures and 75% of the mRRC 2 closures were stable or improved to an mRRC 1 or 2 at follow-up.

Conclusions

The LVIS Blue represents a safe option as a coil adjunct for endovascular embolization within both the proximal and distal anterior and posterior circulation.

Stent-assisted coiling of intracranial aneurysms using LEO stents: long-term follow-up in 153 patients

PURPOSE

Coiling associated with placement of a self-expandable intracranial stent has improved the treatment of intracranial wide-necked aneurysms. Little is known, however, about the durability of this treatment. The purpose of this report is to present our experience with the LEO stent and to evaluate the complications, effectiveness, and long-term results of this technique.

METHODS

We analyzed the records of 155 intracranial unruptured aneurysms that were treated by stent-assisted coiling with a LEO stent between 2008 and 2012. Procedural, early post-procedural, and delayed complications were recorded. Clinical and angiographic follow-up of patients was conducted over a period of at least 36 months.

RESULTS

No procedural mortality was observed. One-month morbidity was observed in 14 out of 153 patients (9,15%). One hundred thirty-eight patients (with 140 aneurysms) had clinical and angiographic follow-up for more than 36 months. No aneurysm rupture was observed during follow-up. Four patients presented an intra-stent stenosis at 8 months, and 6 patients who had an early recurrence were retreated. Final results showed 85% complete occlusion, 13% neck remnants, and 2% stable incomplete occlusion.

CONCLUSION

Stent-assisted coiling with the LEO stent is a safe and effective treatment for unruptured intracranial aneurysms. The long-term clinical outcomes with the LEO stent are excellent with a high rate of complete occlusion that is stable over time.

Therapeutic effect of enterprise stent-assisted embolization for very small ruptured intracranial aneurysms

Enterprise stent has been widespread used in wide-necked intracranial aneurysms and good efficacy has been achieved, but there are few reports on its applications in very small ruptured intracranial aneurysms in literatures. This study aimed to evaluate the safety and efficacy of Enterprise stent-assisted coiling embolization of very small ruptured intracranial aneurysms.We retrospectively reviewed the clinical and imaging data from 37 patients with very small ruptured intracranial aneurysms who had SAC using Enterprise stents performed from February 2012 to July 2016 in our department. Data collected and analyzed included patient demographics, morphologic features of the aneurysm, treatment results, and follow-up results. Clinical outcomes were evaluated by the Glasgow Outcome Scale (GOS).Enterprise stents were successfully implanted in all 37 patients with very small ruptured intracranial aneurysms. Of the 37 individuals, 28 patients exhibited complete occlusion at Raymond grade I, 5 patients exhibited occlusion at Raymond grade II, and 4 patients at Raymond grade III. Procedure-related complications occurred in 3 of 37 patients (8.1%), including 1 case of intraprocedure aneurysm rupture who died from cerebral herniation caused by severe postoperative cerebral ischemia during the hospital stay, and the other 2 complications were acute in-stent thrombosis, and occlusion of parent artery caused by falling-off internal carotid artery plaque, respectively. A total of 36 patients underwent postoperative clinical follow-up visits for 6 to 24 months of which 31 patients recovered (GOS ≥ 4). One patient had hemiplegic paralysis, and no rehemorrhage was found. A total of 25 patients underwent follow-up digital subtraction angiography (DSA) at 3-21 months postintervention, in whom there were 22 cases with complete occlusion, 2 cases with recurrence of aneurysm neck, and 1 case with in-stent restenosis, but there was no patient with neurologic deficits.The Enterprise stent-assisted coiling embolization can be a safe and effective technique for treatment of very small ruptured intracranial aneurysms.

Dual microcatheter coil embolization of acutely ruptured wide-necked intracranial aneurysms

The dual microcatheter technique is an alternative treatment for stent-assisted coiling in acutely ruptured wide-necked aneurysms because of no antiplatelet therapy. We assessed the safety and efficacy of this technique in ruptured wide-necked aneurysms. Between March 2008 and March 2016, 56 acutely ruptured aneurysms were treated with the dual microcatheter technique. The angiographic results, treatment-related complications, and clinical outcome were documented. Angiographic follow-up was available in 37 patients at a mean of 20.6 months (6 to 81 months). On the postembolization angiograms, 27 (48.2%) aneurysms showed complete occlusion (Raymond 1), 15 (26.8%) showed neck remnant (Raymond 2), and 14 (25.0%) showed body remnant (Raymond 3). Treatment-related complications occurred in seven patients (12.5%) and six patients remained asymptomatic. The permanent complication rate was 1.8% (1/56). A good outcome (modified Rankin Scale (mRS) score, 0-2) was observed in 64.3% of patients at the time of discharge. Five patients had died, all of the sequelae of subarachnoid hemorrhage. The overall mortality rate was 8.9% (5/56); however, the treatment-related mortality rate was 0%. Of the 37 aneurysms for which angiographic follow-up was available, 21 (56.8%) aneurysms demonstrated recanalization. Five aneurysms with recanalization were retreated endovascularly. There was one aneurysm re-rupture on follow-up and it rebled 21 months after the initial procedure. The dual microcatheter technique is a safe and effective treatment for acutely ruptured wide-necked aneurysms due to low treatment-related complication and mortality rate. However, the high rate of postembolization incomplete occlusion and recanalization remains as the main challenge.

Non-Contrast-Enhanced Silent Scan MR Angiography of Intracranial Anterior Circulation Aneurysms Treated with a Low-Profile Visualized Intraluminal Support Device

BACKGROUND AND PURPOSE

The Low-Profile Visualized Intraluminal Support Device comprises a small-cell nitinol structure and a single-wire braided stent that provides greater metal coverage than previously reported intracranial stents, as well as assumed strong susceptibility artifacts. This study aimed to assess the benefits of non-contrast-enhanced MRA by using a Silent Scan (Silent MRA) for intracranial anterior circulation aneurysms treated with Low-Profile Visualized Intraluminal Support Device stents.

MATERIALS AND METHODS

Thirty-one aneurysms treated with Low-Profile Visualized Intraluminal Support Device stents were assessed by using Silent MRA, 3D TOF-MRA, and x-ray DSA. The quality of MRA visualization of the reconstructed artery was graded on a 4-point scale from 1 (not visible) to 4 (excellent). Aneurysm occlusion status was evaluated by using a 2-grade scale (total occlusion/remnant [neck or aneurysm]). Weighted κ statistics were used to evaluate interobserver and intermodality agreement.

RESULTS

The mean scores ± SDs for Silent MRA and 3D TOF-MRA were 3.16 ± 0.79 and 1.48 ± 0.67 (P < .05), respectively, with substantial interobserver agreement (κ = 0.66). The aneurysm occlusion rates of the 2-grade scale (total occlusion/remnant [neck or aneurysm]) were 69%/31% for DSA, 65%/35% for Silent MRA, and 92%/8% for 3D TOF-MRA, respectively. The intermodality agreements were 0.88 and 0.30 for DSA/Silent MRA and DSA/3D TOF-MRA, respectively.

CONCLUSIONS

Silent MRA seems to be useful for visualizing intracranial anterior circulation aneurysms treated with Low-Profile Visualized Intraluminal Support Device stents.

Pipeline flow diversion of ruptured blister aneurysms of the supraclinoid carotid artery using a single-device strategy

OBJECTIVE

Ruptured blister aneurysms remain challenging lesions for treatment due to their broad, shallow anatomy and thin, fragile wall. Historical challenges with both open microsurgical approaches and intrasaccular endovascular approaches have led to increased use of flow diversion for management of these aneurysms. However, the optimum paradigm, including timing of treatment, use of dual antiplatelet therapy, and number of flow-diverter devices to use remains unknown. The authors describe their experience with ruptured blister aneurysms treated with flow diversion at their institution, and discuss rates of rebleeding and number of devices used.

METHODS

All patients presenting with subarachnoid hemorrhage from a ruptured blister aneurysm and treated with Pipeline flow diversion were identified. Patient demographic data, clinical status and course, need for external ventricular drain (EVD), timing of treatment, and angiographic details and follow-up were recorded.

RESULTS

There were 13 patients identified (11 women and 2 men), and 4 had multiple aneurysms. Two aneurysms were treated on initial angiography, with average time to treatment of 3.1 days for the remainder, after discussion with the family and institution of dual antiplatelet therapy. Device placement was technically successful in all patients, with 2 patients receiving 2 devices and the remainder receiving 1 device. There was 1 intraoperative complication, of a wire perforation causing intracerebral hemorrhage requiring decompressive craniectomy. Three patients had required EVD placement for management of hydrocephalus. There was no rebleeding from the target lesion; however, one patient had worsening intraventricular hemorrhage and another had rupture of an unrecognized additional aneurysm, and both died. Of the other 11 patients, 10 made a good recovery, with 1 remaining in a vegetative state. Nine underwent follow-up angiography, with 5 achieving complete occlusion, 2 with reduced aneurysm size, and 2 requiring retreatment for aneurysm persistence or enlargement. There were no episodes of delayed rupture.

CONCLUSIONS

Pipeline flow diversion is a technically feasible and effective treatment for ruptured blister aneurysms, particularly in good-grade patients without hydrocephalus. Patients with a worse grade on presentation and requiring EVDs may have higher risk for bleeding complications and poor outcome. There was no rebleeding from the target lesion with use of a single device in this series.

Complications associated with the use of flow-diverting devices for cerebral aneurysms: a systematic review and meta-analysis

OBJECTIVE

The objective of this study was to review the literature on the use of flow-diverting devices (FDDs) to treat intracranial aneurysms (IAs) and to investigate the safety and complications related to FDD treatment for IAs by performing a meta-analysis of published studies.

METHODS

A systematic electronic database search was conducted using the Springer, EBSCO, PubMed, Medline, and Cochrane databases on all accessible articles published up to January 2016, with no restriction on the publication year. Abstracts, full-text manuscripts, and the reference lists of retrieved articles were analyzed. Random-effects meta-analysis was used to pool the complication rates across studies.

RESULTS

Sixty studies were included, which involved retrospectively collected data on 3125 patients. The use of FDDs was associated with an overall complication rate of 17.0% (95% confidence interval [CI] 13.6%–20.5%) and a low mortality rate of 2.8% (95% CI 1.2%–4.4%). The neurological morbidity rate was 4.5% (95% CI 3.2%–5.8%). No significant difference in the complication or mortality rate was observed between 2 commonly used devices (the Pipeline embolization device and the Silk flow-diverter device). A significantly higher overall complication rate was found in the case of ruptured IAs than in unruptured IA (odds ratio 2.3, 95% CI 1.2–4.3).

CONCLUSIONS

The use of FDDs in the treatment of IAs yielded satisfactory results with regard to complications and the mortality rate. The risk of complications should be considered when deciding on treatment with FDDs. Further studies on the mechanism underlying the occurrence of adverse events are required.

Semi-Jailing Technique Using a Neuroform3 Stent for Coiling of Wide-Necked Intracranial Aneurysms

Objective

The semi-jailing technique (SJT) provides stent-assisted remodeling of the aneurysm neck during coil embolization without grasping the coil delivery microcatheter. We retrospectively evaluated the efficacy and safety of SJT using a Neuroform3 stent for coiling of wide-necked intracranial aneurysms.

Methods

We collected the clinical and radiological data between January 2009 and June 2015 of the wide-necked aneurysms treated with SJT using a Neuroform3 stent.

Results

SJT using a Neuroform3 stent was attempted in 70 wide-necked aneurysms (68 patients). There were 56 unruptured and 14 ruptured aneurysms. The size of aneurysm ranged from 1.7 to 28.1 mm (mean 6.1 mm). The immediate angiographic results were complete occlusion in 55 aneurysms (78.6%), neck remnant in 7 (10.0%), and aneurysm remnant in 8 (11.4%). Overall, periprocedural complications occurred in 13 patients (19.1%), including asymptomatic thromboembolism in 7 (10.3%), symptomatic thromboembolism in 4 (5.9%), and symptomatic hemorrhagic complications in 2 (2.9%). Conventional angiography follow-up was obtained in 55 (78.6%) of 70 aneurysms (mean, 10.9 months). The result showed progressive occlusion in 7 aneurysms (12.7%) and recanalization in 1 aneurysm (1.8%). At the end of the observation period (mean, 17.5 months), all 54 patients without subarachnoid hemorrhage showed excellent clinical outcomes (modified Rankin Scale [mRS] 0), except two (mRS 1 or 2) and seven of 14 patients with subarachnoid hemorrhage remained symptom-free (mRS 0).

Conclusion

In this report of 70 aneurysms, SJT using a Neuroform3 stent for coiling of wide-necked intracranial aneurysms showed good technical safety, as well as favorable clinical and angiographic outcomes.

Prasugrel versus clopidogrel in stent-assisted coil embolization of unruptured intracranial aneurysms

Background Thromboembolic complications are the main problem in stent-assisted coil embolization of unruptured intracranial aneurysms. The combination of aspirin and clopidogrel is generally used to decrease these complications, but some patients do not respond to clopidogrel and have a higher risk of stent thrombosis. In cardiology, clinical trials have shown that prasugrel reduced the incidence of ischaemic events in patients with acute coronary syndrome compared with clopidogrel but, according to several authors, prasugrel would produce an increased risk of cerebral haemorrhagic complications. Objective The purpose of this study was to determine whether prasugrel would be more effective than clopidogrel in reducing procedural events in patients with an unruptured aneurysm treated endovascularly with coils and stent. Materials and methods Two hundred consecutive patients with intracranial aneurysms were treated using coiling and stenting procedures. The first 100 patients were administered a dual antiplatelet of aspirin and clopidogrel, while the remaining 100 patients were administered a dual antiplatelet of aspirin and prasugrel. In each group data were collected on procedural and periprocedural haemorrhagic and ischaemic complications. Results Aneurysmal occlusion and haemorrhagic complications rates were identical in both groups. The number of thromboembolic events observed in the two groups of our study did not differ significantly, but the prasugrel group included more wide-neck aneurysms and more flow-diverted stents. Moreover, complications in the prasugrel group were more benign, explaining the significant difference in clinical outcomes between the two groups on Day 30. Conclusions Prasugrel reduces the clinical consequences of thromboembolic complications of endovascular treatment with stenting and coiling of unruptured intracranial aneurysms.

Observation of Neointimal Coverage Around the Aneurysm Neck After Stent-Assisted Coil Embolization by Optical Frequency Domain Imaging: Technical Case Report

BACKGROUND AND IMPORTANCE: Stent-assisted coil embolization has been established as a treatment option for wide-necked or complex aneurysms. However, concerns have been raised about the incidence of thromboembolic complications, which is higher for coil embolization without stent assistance. Long-term antiplatelet therapy is necessary to prevent acute or delayed ischemic events potentially associated with incomplete stent apposition after treatment with stent-assisted coil embolization. Optical frequency domain imaging (OFDI) provides excellent-resolution images of intraluminal structures, allowing evaluation of the outcomes of stent-assisted procedures in terms of stent apposition and neointimal coverage. We here describe the novel use of OFDI for the observation of intravascular tissue formation after stent-assisted coil embolization.

CLINICAL PRESENTATION: Two patients were treated with stent-assisted coil embolization for unruptured vertebral artery aneurysm. At the 1- or 2-yr follow-up visit, routine angiography followed by OFDI were performed to evaluate neointimal coverage of the stent strut and stent apposition to the vascular wall. OFDI enabled clear visualization of the vessel wall structures and demonstrated complete coverage of the stent struts as well as full stent wall apposition in 1 patient and incomplete coverage near the aneurism neck as well as mallaposition of some struts in the other patient.

CONCLUSION: OFDI represents a feasible modality for the evaluation of intracranial vasculature and the outcomes of stent-assisted coil embolization in terms of intimal healing of aneurysms, stent-vessel interactions, and neointimal coverage of the stent. Such information is helpful in determining the duration of antiplatelet therapy after stent-assisted coil embolization.