ARISE I Consensus Review on the Management of Intracranial Aneurysms.

BACKGROUND: Intracranial aneurysms (IAs) remain a challenging neurological diagnosis associated with significant morbidity and mortality. There is a plethora of microsurgical and endovascular techniques for the treatment of both ruptured and unruptured aneurysms. There is no definitive consensus as to the best treatment option for this cerebrovascular pathology. The Aneurysm, Arteriovenous Malformation, and Chronic Subdural Hematoma Roundtable Discussion With Industry and Stroke Experts discussed best practices and the most promising approaches to improve the management of brain aneurysms. METHODS: A group of experts from academia, industry, and federal regulators convened to discuss updated clinical trials, scientific research on preclinical system models, management options, screening and monitoring, and promising novel device technologies, aiming to improve the outcomes of patients with IA. RESULTS: Aneurysm, Arteriovenous Malformation, and Chronic Subdural Hematoma Roundtable Discussion With Industry and Stroke Experts suggested the incorporation of artificial intelligence to capture sequential aneurysm growth, identify predictors of rupture, and predict the risk of rupture to guide treatment options. The consensus strongly recommended nationwide systemic data collection of unruptured IA radiographic images for the analysis and development of machine learning algorithms for rupture risk. The consensus supported centers of excellence for preclinical multicenter trials in areas such as genetics, cellular composition, and radiogenomics. Optical coherence tomography and magnetic resonance imaging contrast-enhanced 3T vessel wall imaging are promising technologies; however, more data are needed to define their role in IA management. Ruptured aneurysms are best managed at large volume centers, which should include comprehensive patient management with expertise in microsurgery, endovascular surgery, neurology, and neurocritical care. CONCLUSIONS: Clinical and preclinical studies and scientific research on IA should engage high-volume centers and be conducted in multicenter collaborative efforts. The future of IA diagnosis and monitoring could be enhanced by the incorporation of artificial intelligence and national radiographic and biologic registries. A collaborative effort between academic centers, government regulators, and the device industry is paramount for the adequate management of IA and the advancement of the field.

Use of a large-bore 088 intracranial access support catheter for delivery of large intracranial devices: case series with the TracStar LDP in 125 cases.

BACKGROUND: The delivery of neuroendovascular devices requires a robust proximal access platform. This demand has previously been met with a 6Fr long sheath (8Fr guide) that is placed in the proximal internal carotid artery (ICA) or vertebral artery segments. We share our experience with the first 0.088 inch 8Fr guide catheter designed for direct intracranial access. METHODS: We retrospectively reviewed a prospectively maintained IRB-approved institutional database of the senior authors to identify all cases where the TracStar Large Distal Platform (LDP) was positioned within the intracranial vasculature, defined as within or distal to the petrous ICA, vertebral artery (V3) segments, or transverse sinus. Technical success was defined as safe placement of the TracStar LDP within or distal to the described distal vessel segments with subsequent complication-free device implantation. RESULTS: Over the 41-month study period from January 2020 to June 2023, 125 consecutive cases were identified in whom the TracStar LDP was navigated into the intracranial vasculature for triaxial delivery of large devices, 0.027 inch microcatheter and greater, for aneurysm treatment (n=108, 86%), intracranial angioplasty/stenting (n=15, 12%), and venous sinus stenting (n=2, 1.6%). All cases used a direct select catheter technique for initial guide placement (no exchange). Posterior circulation treatments occurred in 14.4% (n=18) of cases. Technical success was achieved in 100% of cases. No vessel dissections occurred in any cases. CONCLUSION: The TracStar LDP is an 0.088 inch 8Fr guide catheter that can establish direct intracranial access with an acceptable safety profile. This can be achieved in a wide range of neurointerventional cases with a high rate of technical success.

Feasibility of super-bore 0.088″ mechanical thrombectomy in M1 vessels smaller than 8 French: Experience in 20 consecutive cases.

INTRODUCTION: Superbore 0.088″ catheters provide a platform for optimizing aspiration efficiency and flow control during stroke mechanical thrombectomy procedures. New superbore catheters have the distal flexibility necessary to navigate complex neurovascular anatomy while providing the proximal support of traditional 8F catheters. The safety and feasibility of Zoom 88™ superbore angled-tip catheters in the middle cerebral artery (MCA) segments smaller than the catheter diameter have not been previously described. METHODS: Twenty consecutive cases of acute MCA mechanical thrombectomy were retrospectively identified from the senior authors' prospectively maintained Institutional Review Board-approved database, in which the Zoom 88 (Imperative Care, Campbell, CA) catheter was successfully navigated to at least the M1 segment. Patient demographics, procedural details, and periprocedural information were analyzed. Rates and averages (standard errors) are generally reported. RESULTS: The average National Institutes of Health Stroke Scale at presentation and age were 15 ± 2 and 73 ± 3 years, respectively. The M1 and M2 occlusions were evenly distributed. The average M1 measurements before thrombectomy ranged from 2.36 ± 0.07 mm proximally to 2.00 ± 0.11 mm distally, and after thrombectomy, they ranged from 2.34 ± 0.07 mm proximally to 1.97 ± 0.10 mm distally. First-pass modified thrombolysis in cerebral infarction (mTICI) 2C/3 recanalization was achieved in 40% of cases, and final mTICI 2C/3 recanalization was achieved in 90% of cases. A single case of mild vasospasm was managed with verapamil. No hemorrhagic or periprocedural complications were noted. CONCLUSION: Superbore 0.088″ catheters with flexible distal segments can be safely navigated to the MCA to augment mechanical thrombectomy even when the MCA segment is smaller than the catheter.

Triple Stentriever "Bouquet" Deployment with Zoom 88 Large-Bore Aspiration and Walrus Balloon-Guide Catheter for the Definitive Thrombectomy of a Carotid Free-Floating Thrombus.

Formation of a carotid free-floating thrombus (CFFT) is a rare and life-threatening condition without an optimal management plan. A 78-year-old woman with a history of prior right internal carotid artery (ICA) mechanical thrombectomy and antiplatelet noncompliance presented with transient ischemic attacks secondary to a recurrent CFFT in the right ICA. Given her symptoms and recurrent CFFT, endovascular mechanical thrombectomy was performed. A balloon guide-catheter (BGC) and a Zoom 88 distal access catheter were brought into the right distal common carotid artery and proximal ICA bulb, respectively. Three 0.021-inch microcatheters, each loaded with a unique stentriever, were navigated beyond the thrombus into the upper cervical ICA and deployed in a bouquet fashion. The BGC was inflated to achieve flow arrest, and the Zoom 88 aspiration catheter was tracked over the three bouquet stentrievers to ingest the thrombus. Follow-up angiography demonstrated recanalization of the proximal cervical ICA without evidence of residual thrombus. Twenty-four-hour postoperative computed tomography imaging did not reveal any evidence of new infarction. The patient was discharged home with an intact neurological examination, compliant on aspirin and apixaban. We demonstrate a novel technique utilizing a large-bore catheter with a triple stentriever "bouquet" to thrombectomize a CFFT.

Immediate procedural safety of adjunctive proximal coil occlusion in middle meningeal artery embolization for chronic subdural hematomas: Experience in 137 cases.

BACKGROUND: Endovascular embolization of the middle meningeal artery (MMA) has emerged as an adjunctive and stand-alone modality for the management of chronic subdural hematomas (cSDH). We report our experience utilizing proximal MMA coil embolization to augment cSDH devascularization in MMA embolization. METHODS: MMA embolization cases with adjunctive proximal MMA coiling were retrospectively identified from a prospectively maintained IRB-approved database of the senior authors. RESULTS: Of the 137 cases, all patients (n = 89, 100%) were symptomatic and underwent an MMA embolization procedure for cSDH. 50 of the patients underwent bilateral embolizations, with 53% (n = 72) for left-sided and 47% (n = 65) for right-sided cSDH. The anterior MMA branch was embolized in 19 (14%), posterior in 16 (12%), and both in 102 (74.5%) cases. Penetration of the liquid embolic to the contralateral MMA or into the falx was present in 38 (28%) and 31 (23%) cases, respectively, and 46 (34%) cases had ophthalmic or petrous collateral (n = 41, 30%) branches. MMA branches coiled include the primary trunk (25.5%, n = 35), primary and anterior or posterior MMA trunks (20%, n = 28), or primary with the anterior and posterior trunks (54%, n = 74). A mild ipsilateral facial nerve palsy was reported, which remained stable at discharge and follow-up. Absence of anterograde flow in the MMA occurred in 137 (100%) cases, and no cases required periprocedural rescue surgery for cSDH evacuation. The average follow-up length was 170 ± 17.9 days, cSDH was reduced by 4.24 ± 0.5(mm) and the midline shift by 1.46 ± 0.27(mm). Complete resolution was achieved in 63 (46.0%) cases. CONCLUSION: Proximal MMA coil embolization is a safe technique for providing additional embolization/occlusion of the MMA in cSDH embolization procedures. Further studies are needed to evaluate the potential added efficacy of this technique.

Trends in Dual Antiplatelet Therapy Use for Neurointerventional Procedures for the Management of Intracranial Aneurysms.

The use of periprocedural dual antiplatelet therapy (DAPT) has significantly evolved along with innovations in the endovascular management of intracranial aneurysms. Historically, aspirin and clopidogrel have been the most commonly employed regimen due to its safety and efficacy. However, recent studies highlight the importance of tailoring DAPT regimens to individual patient characteristics which may affect clopidogrel metabolism, such as genetic polymorphisms. In the present report, a systematic review of the literature was performed to determine optimal antiplatelet use with flow diverting stents, intracranial stents, intrasaccular devices, and stent-assisted coiling. Studies were analyzed for the number of aneurysms treated, DAPT regimen, and any thromboembolic complications. Based on inclusion criteria, 368 studies were selected, which revealed the increasing popularity of alternative DAPT regimens with the aforementioned devices. Thromboembolic or hemorrhagic complications associated with antiplatelet medications were similar across all medications. DAPT with ticagrelor, tirofiban, or prasugrel are effective and safe alternatives to clopidogrel and do not require enzymatic activation. Further clinical trials are needed to evaluate different antiplatelet regimens with various devices to establish highest-level evidence-based guidelines and recommendations.

Augmentation of flow diverter vessel wall apposition using the Comaneci device: case experience from a novel, off-label technique.

BACKGROUND: Flow diversion (FD) embolization of intracranial cerebral aneurysms is an increasingly common modality where treatment success depends on adequate vessel wall apposition of the device. This study aimed to investigate off-label use of the Comaneci device for augmenting vessel wall apposition in post-deployed flow diversion stents (FDS). METHODS: Over a 20- month period, all FD cases for the treatment of internal carotid artery (ICA) aneurysms were reviewed. Cases in which the Comaneci device was used to augment vessel wall apposition were analyzed. Data including patient demographics, case characteristics, and procedural outcomes were collected and analyzed as counts. RESULTS: From a total of 74 ICA FD cases, the Comaneci device was used to improve vessel wall apposition in 22 cases (29.7%) . Of these cases, 91% were female with a mean patient age of 64.9±11.3 years, and an average aneurysm size of 4.5±2.5 mm. Comaneci device deployment and retrieval was successful in all (100%) cases, with an average fluoroscopy time of 27.3±7.8 min, an average contrast usage of 25.8±13.2 mL, and an average radiation exposure of 915.1±320.8 mGy. Only two cases (9%) required subsequent balloon angioplasty after Comaneci deployment to improve vessel wall apposition throughout the FDS. CONCLUSION: Our experience with this technique demonstrates the feasibility of using the Comaneci device for augmentation of FDS vessel wall apposition with 100% success in the deployment and retrieval of the Comaneci device.

Treatment of large and giant posterior communicating artery aneurysms with the Surpass streamline flow diverter: results from the SCENT trial.

BACKGROUND: The Surpass flow diverter was developed to treat intracranial aneurysms not amenable to standard treatment. Indications for use allow placement in the internal carotid artery to the terminus, including the communicating artery segment. METHODS: The Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide Neck Aneurysms (SCENT) trial is an international, multicenter, prospective, non-randomized trial comparing the outcomes of Surpass flow diverter treatment with historic control designed to evaluate the effectiveness and safety of Surpass for the treatment of wide neck (≥4 mm) large or giant intracranial aneurysms ≥10 mm. The primary effectiveness endpoint is the percentage of subjects with 100% aneurysm occlusion without significant stenosis of the parent artery and without retreatment of the target aneurysm at 12 months. The primary safety endpoint is the percentage of subjects experiencing neurologic death or major ipsilateral stroke at 12 months. We report the effectiveness and safety of flow diversion in the subgroup of posterior communicating artery (PComA) aneurysms. RESULTS: Of the 180 patients treated, 38 harbored a PComA aneurysm. Mean aneurysm size was 12.2 mm and mean neck width was 4.8 mm. The mean number of Surpass devices used was 1.1 per procedure, with 94.7% of aneurysms treated with one flow diverter. The 12 month primary effectiveness rate was 73.7% (28/38). At 36 months, 68.4% (26/38) of aneurysms remained completely occluded. The 12 month major ipsilateral stroke or neurological death rate was 10.5%. No patients with PComA occlusion after flow diverter placement (54.5%) had clinical sequelae. CONCLUSIONS: SCENT demonstrated acceptable 12 month effectiveness of flow diversion in PComA aneurysms. Despite associated PComA occlusions in many cases, arterial occlusions were clinically silent. TRIAL REGISTRATION NUMBER: URL: https://www. CLINICALTRIALS: gov. Unique identifier: NCT01716117.

Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide-Neck Aneurysms - SCENT: 3-year outcomes.

BACKGROUND: To report the 3-year safety and effectiveness of the Surpass Streamline flow diverter in the SCENT trial (Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide-Neck Aneurysms). METHODS: The Surpass Streamline flow diverter device was evaluated in a multicenter, prospective, single-arm, non-randomized interventional trial including patients with uncoilable or previously treated but failed aneurysms of the intracranial internal carotid artery. 3-year outcomes were tabulated with descriptive statistics and compared with 1-year outcomes. RESULTS: Of 180 patients in the modified intent-to-treat (mITT) cohort, 36-month clinical and angiographic follow-up was available in 134 and 117 cases, respectively. Effectiveness endpoint of complete aneurysm occlusion without clinically significant stenosis or retreatment was met in 71.8% (79/110, 95% CI 62.4% to 80.0%) of cases. Safety composite endpoint was 12.2% (22/180) over the 3-year period, with two major safety events (ipsilateral ischemic strokes) occurring between 12-36 months. Complete aneurysm occlusion was noted in 77.8% (91/117), and 99.1% (116/117) of the patients demonstrated adequate aneurysm occlusion (complete occlusion or neck residual). There were four cases (2.2%) of aneurysm rupture, all occurring within the first month of the index procedure. Target aneurysm retreatment rate was 2.8% (5/180). CONCLUSION: The present findings support the long-term safety and effectiveness of the Surpass Streamline flow diverter device. TRIAL REGISTRATION: NCT01716117.

Combined Pipeline Embolization Device with Endoscopic Endonasal Fascia Lata/Muscle Graft Repair as a Salvage Technique for Treatment of Iatrogenic Carotid Artery Pseudoaneurysm.

The incidence of internal carotid artery (ICA) injury associated with endoscopic endonasal approaches to the pituitary is less than 1%. While parent vessel sacrifice has historically been the choice of treatment, vessel-preserving endovascular techniques have been reported. Although flow diversion offers endoluminal reconstruction, its major limitation is the delay in obtaining complete occlusion. We describe the use of a combined Pipeline embolization device (PED) with endoscopic endonasal repair using a fascia lata/muscle graft to treat an iatrogenic ICA pseudoaneurysm and report long-term radiographic follow-up. Further investigation into the utility of directed endoscopic endonasal repair of iatrogenic pseudoaneurysms initially treated with PED is necessary, especially given the need of post-PED anticoagulation and the rate of permanent neurological deficit after ICA sacrifice.

International teleproctoring in neurointerventional surgery and its potential impact on clinical trials in the era of COVID-19: legal and technical considerations.

BACKGROUND: Existing travel restrictions limit the mobility of proctors, significantly delaying clinical trials and the introduction of new neurointerventional devices. We aim to describe in detail technical and legal considerations regarding international teleproctoring, a tool that could waive the need for in-person supervision during procedures. METHODS: International teleproctoring was chosen to provide remote supervision during the first three intracranial aneurysm treatments with a new flow diverter (currently subject of a clinical trial) in the US. Real-time, high-resolution transmission software streamed audiovisual data to a proctor located in Canada. The software allowed the transmission of images in a de-identified, HIPAA-compliant manner. RESULTS: All three flow diverters were implanted as desired by operator and proctor and without complication. The proctor could swap between images from multiple sources and reported complete spatial and situational awareness, without any significant lag or delay in communication. Procedural times and radiologic dose were similar to those of uncomplicated, routine flow diversion cases at our institution. CONCLUSIONS: International teleproctoring was successfully implemented in our clinical practice. Its first use provided important insights for establishing this tool in our field. With no clear horizon for lifting the current travel restrictions, teleproctoring has the potential to remove the need for proctor presence in the angiography suite, thereby allowing the field to advance through the continuation of trials and the introduction of new devices in clinical practice. In order for this tool to be used safely and effectively, highly reliable connection and high-resolution equipment is necessary, and multiple legal nuances have to be considered.

Twisting: Incidence and Risk Factors of an Intraprocedural Challenge Associated With Pipeline Flow Diversion of Cerebral Aneurysms.

BACKGROUND: Pipeline Embolization Device (PED; Medtronic) "twisting" manifests with the appearance of a "figure 8" in perpendicular planes on digital subtraction angiography. This phenomenon has received little attention in the literature, requires technical precision to remediate, and has potential to cause ischemic stroke if not properly remediated. OBJECTIVE: To report incidence, risk factors, and sequelae of PED twisting and to discuss techniques to remediate a PED twist. METHODS: Case images were reviewed for instances of twisting from a prospectively-maintained, Institutional Review Board-approved cohort of patients undergoing flow diversion for cerebral aneurysm. RESULTS: From August 2011 to December 2017, 999 PED flow diverting stents were attempted in 782 cases for 653 patients. A total of 25 PED twists were observed while treating 20 patients (2.50%, 25/999). Multivariate analysis revealed predictors of twisting to be: Large and giant aneurysms (odds ratio (OR) = 9.66, P = .005; OR = 27.47, P < .001), increased PED length (OR = 1.14, P < .001), and advanced patient age (OR = 1.07, P = .002). Twisted PEDs were able to be remediated 75% of the time, and procedural success was achieved in 90% of cases. PED twisting was not found to be a significant cause of major or minor complications. However, at long-term follow-up, there was a trend towards poor occlusion outcomes for the cases that encountered twisting. CONCLUSION: Twisting is a rare event during PED deployment that was more likely to occur while treating large aneurysms with long devices in older patients. While twisting did not lead to major complications in this study, remediation can be challenging and may be associated with inferior occlusion outcomes.

Advances in endovascular aneurysm management: flow modulation techniques with braided mesh devices.

Flow diverters and flow disruption technology, alongside nuanced endovascular techniques, have ushered in a new era of treating cerebral aneurysms. Here, we provide an overview of the latest flow modulation devices and highlight their clinical applications and outcomes.

Updates in the management of cranial dural arteriovenous fistula.

Dural arteriovenous fistula (dAVF) accounts for approximately 10% of all intracranial vascular malformations. While they can be benign lesions, the presence of retrograde venous drainage and cortical venous reflux makes the natural course of these lesions aggressive high risk of haemorrhage, neurological injury and mortality. Endovascular treatment is often the first line of treatment for dAVF. Both transarterial and transvenous approaches are used to cure dAVF. The selection of treatment approach depends on the angioarchitecture of the dAVF, the location, the direction of venous flow. Surgery and, to a lesser extent, stereotactic radiosurgery are used when endovascular approaches are impossible or unsuccessful.

Cerebral aneurysm treatment trends in National Inpatient Sample 2007-2016: endovascular therapies favored over surgery.

BACKGROUND: Flow modulation is the newest endovascular technique for treatment of cerebral aneurysms. OBJECTIVE: To investigate changes in aneurysm treatment practice patterns in the USA. METHODS: From the 2007 to 2016, the National Inpatient Sample databases, hospital discharges associated with unruptured aneurysms (UA), and/or ruptured aneurysms (RA) having undergone surgical clipping (SC) and/or endovascular treatments (EVT) were identified using the International Classification of Diseases codes. Patient demographics, hospital characteristics, and clinical outcomes were reviewed. Five year subgroup analyses were performed for treatment differences. RESULTS: A total of 39 282 hospital discharges were identified with a significant increase in EVT (UA: SC n=7847 vs EVT n=12 797, p<0.001; RA: SC n=8108 vs EVT n=10 530, p<0.001). Hospitals in the South demonstrated the most significant EVT use regardless of aneurysm status (UA: SC n=258.5±53.6 vs EVT n=480.7±155.8, p<0.001; RA: SC n=285.6±54.3 vs EVT n=393.3±102.9, p=0.003). From 2007 to 2011, there was no significant difference in the mean number of cases for the treatment modalities (UA: SC n=847.4±107.7 vs EVT n=1120.4±254.1, p=0.21; RA: SC n=949.4±52.8 vs EVT n=1054.4±219.6, p=0.85). Comparatively, from 2012 to 2016, significantly more UA and RA were treated endovascularly (UA: SC n=722.0±43.4 vs EVT n=1439.0±419.2, p<0.001; RA: SC n=672.2±61.4 vs EVT n=1051.6±330.2, p=0.02). CONCLUSIONS: As technological innovations continue to advance the neuroendovascular space, the standard of care for treatment of cerebral aneurysms is shifting further towards endovascular therapies over open surgical approaches in the USA.

First clinical experience with the new Surpass Evolve flow diverter: technical and clinical considerations.

OBJECTIVE: To describe the results in patients treated with the Surpass Evolve (SE) device, the new generation of Surpass flow diverters. METHODS: Twenty-five consecutive patients (20 women, average age 58 years), with anterior or posterior circulation aneurysms treated with SEs in two early-user centers, were included. Device properties and related technical properties, imaging and clinical follow-up data, and intraprocedural, early (<30 days) and delayed (>30 days) neurological complications, further divided into minor (silent/non-permanent) and major (permanent) complications, were recorded and analyzed. RESULTS: Twenty-nine SEs were successfully implanted in all subjects to treat 26 aneurysms using an 0.027" microcatheter with an average of 1.2 stents per patient. No intraprocedural thromboembolic or hemorrhagic complications were seen. At clinical follow-up, 24/25 (96%) patients had a modified Rankin Score of 0-2. Mortality was 0%. Imaging follow-up, available in 22/25 (88%) patients (median follow-up time 4 months), showed a complete aneurysm occlusion in 13/23 (57%) imaged lesions. Minor, transitory neurological deficits were recorded in 5/25 (20%) patients. One (4%) major complication was seen in one patient (4%) with a left-sided hemispheric stroke on postprocedural day 4 due to an acute stent thrombosis. CONCLUSIONS: Preliminary experience in patients demonstrates a good performance of the SE. This newly designed implant maintains the engineering characteristics of Surpass flow diverters, including precise placement due to its lower foreshortening and a high mesh density, yet can be deployed through a significantly lower-profile delivery system.

Clinical utility and versatility of the petrous segment of the internal carotid artery in revascularization.

Direct approaches to high cervical lesions, including tumors and aneurysms, carry significant risks. This renders alternative approaches desirable, with vascular disease amenable to exclusion and revascularization to the intracranial circulation, including the petrous or supraclinoid segments of the internal carotid artery (ICA). The cervicopetrous ICA bypass via saphenous venous grafting has proven an effective strategy for treating and excluding these lesions. In current practice, this is performed via an extradural subtemporal approach to access the petrous segment of the ICA and a cervical incision for access to the cervical ICA. The venous graft is alternately tunneled subcutaneously or in situ through the cervical ICA, with the latter eschewing external compression, kinking, and torsion, which increases risk of graft thrombosis with the former. Maxillary or middle meningeal arteries may also serve as donors to the petrous ICA. Moreover, the petrous ICA may be used as a donor in revascularization procedures, to the supraclinoid segment of the ICA and the middle cerebral artery, with petrous supraclinoid and petrous-MCA bypasses described. Clinical utility and operative approaches bypassing to or from the petrous ICA in revascularization procedures are reviewed and discussed.

Aspirin Monotherapy in Flow Diversion of Selected Internal Carotid Artery Aneurysms.

BACKGROUND: Dual antiplatelet therapy has been adopted as the standard of care for intracranial stenting, including flow diversion of cerebral aneurysms, to reduce the risk of acute and delayed ischemic complications. CASE DESCRIPTION: This is a report of 2 cases in which patients who underwent flow diversion of unruptured internal carotid artery aneurysms were treated with aspirin monotherapy. Neither patient tolerated dual antiplatelet therapy, one because of nosebleeds due to hereditary hemorrhagic telangiectasia and one because of an unnamed bleeding disorder. The lesions-a previously coiled, recanalizing dorsal internal carotid artery aneurysm and a small superior hypophyseal aneurysm-were each treated with a single Pipeline Flex embolization device and were completely occluded with normal-appearing parent vessel on 12-month follow-up digital subtraction angiography. CONCLUSIONS: This is the first report of patients electively treated with flow diversion using Pipeline Flex embolization device on aspirin monotherapy in the literature.

Flow diversion covering the M1 origin as a last resort.

INTRODUCTION: Internal carotid artery termination (ICAT) and proximal A1 aneurysms can be challenging for open surgical clipping or endovascular coiling. Treatment with flow diversion covering the middle cerebral artery (MCA), an end vessel supplying a terminal circulation, has not been reported. METHODS: A prospective, Institutional Review Board-approved database was analysed for patients with pipeline embolisation device (PED) placement from the anterior cerebral artery (ACA) to the ICA during cerebral aneurysm treatment. RESULTS: Nine cases were identified, including five proximal A1, three posterior communicating artery and one ICAT aneurysm locations. Average aneurysm size was 8.3 mm (range 3-17), with 67% saccular and 78% right-sided. Primary indication for treatment was significant dome irregularity (44%), recurrence or enlargement (33%), underlying collagen vascular disorder (11%) and traumatic pseudoaneurysm (11%). Preservation of the ipsilateral ACA (with PED placed in A1) was performed when the anterior communicating artery (67%) or contralateral A1 (33%) were absent on angiography. Adjunctive coiling was done in four cases (44%). There was one major stroke leading to mortality (11%) and one minor stroke (11%). Clinical follow-up was 27 months on average. Follow-up digital subtraction angiography (average interval 15 months) showed complete aneurysm obliteration (88%) or dome occlusion with entry remnant (12%). The jailed MCA showed minimal or mild delay (primarily anterograde flow) in 75% of cases and significant delay (reliance primarily on ACA and external carotid artery collaterals) in 25%. CONCLUSIONS: Covering the MCA with a flow diverting stent should be reserved for select rare cases. Strict attention to blood pressure augmentation during the periprocedural period is necessary to minimise potential ischaemic compromise.

A Contemporary Review of Endovascular Treatment of Wide-Neck Large and Giant Aneurysms.

BACKGROUND: Despite widespread use of flow diverters, wide-necked large and giant aneurysms are still treated with other techniques as well. A contemporary review of results from different endovascular treatments is timely. METHODS: A literature review of the English language literature since 2011 was conducted using PubMed and Science Direct. Keywords and Medical Subheadings included large and giant aneurysms, ruptured aneurysms, aneurysms located in posterior circulation, and aneurysm occlusion status. Case reports were excluded. A combined model was built including both flow diverter and coil treatments in addition to separate models. Efficacy and safety were pooled using random effects analysis and regression. RESULTS: The review comprised 29 studies. For coiling techniques, complete occlusion was 40.2%-82.8%, and adjusted regression resulted in 53% (95% confidence interval [CI] 22%-81%). Flow diverter complete occlusion rate was 40.5%-87.8%, and adjusted regression resulted in 87% (95% CI 76%-93%). Overall occlusion rate for both techniques combined was 62%-75%, and adjusted regression resulted in 81% (95% CI 68%-89%). Overall stroke and death regression rate was 5% (95% CI 3%-10%); flow diverters showed slightly higher rates than coiling (6% vs. 3%). CONCLUSIONS: All current treatments of large and giant wide-necked aneurysms have comparable safety and efficacy with a trend of superiority of efficacy toward flow diverters. Results of future treatment options and devices can be compared with current technology to evaluate feasibility.