Vertebral Artery Access Considerations in Coil Embolization of Small Superior Cerebellar Artery Aneurysm.

BACKGROUND: Coiling of small superior cerebellar artery aneurysms (sSCAAs) is challenging. We aimed to describe anatomic considerations in the vertebral and basilar artery (VA and BA) morphology for decision making in the coiling of sSCAAs. METHODS: Eleven patients with sSCAAs (<5 mm) treated at our institution between April 2015 and February 2022 were included to show our concept of deciding access routes in the coiling of sSCAAs. The access route was decided on the basis of VA characteristics, BA curvature, and aneurysm laterality. Adequate aneurysm occlusion on angiography (Raymond-Roy grading scale I and II), good outcome (modified Rankin Score 0-2) at the last follow-up, and adverse outcomes were evaluated. RESULTS: Simple coiling (n = 2), a balloon-assisted technique (n = 3), and stent-assisted technique (n = 6) were selected. At the last follow-up (median 13.0 months), adequate aneurysm occlusion and good outcome were obtained in all 9 patients (n = 10). Adverse outcomes were not observed. When VA dominance was equal, in the straight BA, the microcatheter insertion into the ipsilateral VA to the aneurysm was favorable to form a "fulcrum" on the contralateral side and obtain microcatheter stability. When an aneurysm was on the concave aspect of the curved BA, microcatheter insertion into the ipsilateral VA was favorable. As for the convex aspect's aneurysm location, the microcatheter insertion into the contralateral VA can be favored. Further, we described the VA origin classification as it relates to ease of access from a transradial approach. CONCLUSIONS: Vertebrobasilar morphology may be important in deciding access routes in the coiling of sSCAAs.

Giant Pediatric Dural Arteriovenous Fistula Management Using a Combined Operative Approach in a Hybrid Neuroendovascular Surgery Suite: Technical Nuances and Review of Literature.

BACKGROUND: Pediatric intracranial dural arteriovenous fistulas (dAVFs) are rare, complex entities usually presenting with macrocephaly from increased intracranial pressures at a young age. In the setting of a symptomatic intracranial dAVF that has undergone multiple endovascular treatments with subsequent recurrence or failed embolization attempts, the intracranial venous system can become inaccessible by traditional transvenous and transarterial routes. Direct puncture of the venous sinus for endovascular access after surgical exposure is a viable option. OBJECTIVE: To describe the technical nuances and available literature for direct puncture of the venous sinus for endovascular access in a pediatric patient with dAVF. METHODS: The clinical characteristics were reviewed and reported for a patient who underwent direct puncture of the venous sinus for endovascular access. In addition, a literature review was conducted for relevant literature pertaining to this technique and its associated indications, outcomes, and complications. RESULTS: Only 2 other reports of direct puncture of venous sinus for endovascular access after surgical exposure were found in the literature. Our patient achieved a favorable outcome with complete dAVF obliteration. CONCLUSION: Direct puncture of the venous sinus for endovascular access after surgical exposure for complex dAVFs that are inaccessible by transvenous or transarterial routes is a practical and safe approach to intracranial venous access that should be part of the vascular neurosurgeon's arsenal.

Angiographic Evaluation of Cranial Venous Outflow Patterns in Patients With and Without Idiopathic Intracranial Hypertension.

BACKGROUND: Several collateral venous pathways exist to assist in cranial venous drainage in addition to the internal jugular veins. The important extrajugular networks (EJN) are often readily identified on diagnostic cerebral angiography. However, the angiographic pattern of venous drainage through collateral EJN has not been previously compared among patients with and without idiopathic intracranial hypertension (IIH). OBJECTIVE: To quantify EJN on cerebral angiography among patients both with and without IIH and to determine whether there is a different EJN venous drainage pattern in patients with IIH. METHODS: Retrospective imaging review of 100 cerebral angiograms (50 IIH and 50 non-IIH patients) and medical records from a single academic medical center was performed by 2 independent experienced neuroendovascular surgeons. Points were assigned to EJN flow from 0 to 6 using an increasing scale (with each patient's dominant internal jugular vein standardized to 5 points to serve as the internal reference). Angiography of each patient included 11 separately graded extrajugular networks for internal carotid and vertebral artery injections. RESULTS: Patients in the IIH group had statistically significant greater flow in several of the extrajugular networks. Therefore, they preferentially drained through EJN compared with the non-IIH group. Right transverse-sigmoid system was most often dominant in both groups, yet there was a significantly greater prevalence of codominant sinus pattern on posterior circulation angiograms. CONCLUSION: Patients with IIH have greater utilization of EJN compared with patients without IIH. Whether this is merely an epiphenomenon or possesses actual cause-effect relationships needs to be determined with further studies.

Stand-Alone Large Bore Aspiration Catheter (0.072 Inch) for Both Guide Support and Clot Aspiration in Transradial Posterior Circulation Stroke Thrombectomy: Technical Series.

BACKGROUND: The large size of guide catheters in the traditional triaxial configuration can prove limiting during transradial vertebrobasilar thrombectomy. This is especially important for the direct aspiration technique because of the large aspiration catheters that can reach an inner diameter of 0.072 in. A strategy that strikes a balance between stable proximal vessel support and distal navigation for aspiration is conceptually attractive. OBJECTIVE: To describe a series of transradial posterior circulation thrombectomy procedures in which the aspiration catheter served a dual role of guide support and clot aspiration in a coaxial configuration, thus obviating a larger guide catheter. METHODS: Patients selected in the series underwent radial artery access and direct over-the-wire navigation of the aspiration catheter into the vertebral artery. With coaxial microcatheter navigation, the aspiration catheter reached distal enough to ingest the clot successfully. Along with clinical and angiographic data, imaging features such as angle of vertebral artery origin were calculated. RESULTS: Five patients underwent a stand-alone aspiration catheter technique for basilar artery occlusion through transradial access. All procedures resulted in thrombolysis in cerebral infarction 3 recanalization. The mean time to basilar artery recanalization was 10 minutes. No access site complications or vertebral artery dissection were noted. The mean subclavian artery-vertebral origin angle was 84.06° (range 78.2-90.2°). CONCLUSION: For patients selected properly based on vascular anatomy and a careful technique, a large bore aspiration catheter can fulfil a stand-alone dual-role, thus obviating the need for a guide catheter. This can potentially improve the technical feasibility and success of transradial vertebrobasilar thrombectomy.

SMART Registry: Safety and Performance of the Penumbra SMART COIL System for Patients With Intracranial Aneurysms 4 mm and Smaller.

BACKGROUND: The Penumbra SMART COIL System includes a novel generation of embolic coils composed of complex and WAVE shape properties with varying levels of softness. OBJECTIVE: To assess safety and efficacy of the SMART COIL System through a 1-year follow-up in patients with small intracranial aneurysms. METHODS: This subset analysis of the SMART Registry, a prospective, multicenter study, includes patients with small intracranial aneurysms (≤4 mm) treated with the SMART COIL System. Registry end points include retreatment rates through 1 year, procedural device-related serious adverse events, and adequate occlusion postprocedure. RESULTS: Of 905 enrolled patients with aneurysms, 172 (19.0%) had small (≤4 mm) aneurysms (75.6% female; mean age 57.2 ± 13.4 years). 30.8% (53/172) of small aneurysms were ruptured, of which 50.9% (27/53) had Hunt and Hess ≥3. 79.5% (132/166) were wide-necked. Stent-assisted coiling and balloon-assisted coiling were performed in 37.2% (64/172) and 22.1% (38/172) of patients, respectively. The mean packing density for very small aneurysms was 44.9 (SD 25.23). Raymond Class I and Class II were achieved in 89.5% (154/172) postprocedure and 97.2% (137/141) at 1 year. The retreatment rate through 1 year was 5.6% (8/142), and the recanalization rate was 7.1% (10/141). The periprocedural device-related serious adverse event rate was 2.9% (5/172). Intraprocedural aneurysm rupture occurred in 0.8% of patients. CONCLUSION: This analysis suggests that the SMART COIL System is safe and efficacious in small aneurysms with satisfactory occlusion rates and low rates of rupture or rerupture. At 1 year, patients had low retreatment rates and good clinical outcomes.

Endovascular Management of Distal Anterior Cerebral Artery Aneurysms: A Multicenter Retrospective Review.

INTRODUCTION: Distal anterior cerebral artery aneurysms (DACAA) are a rare and difficult entity to manage. Endovascular treatment has evolved for safe and durable treatment of these lesions. The objective of this study is to report the safety, efficacy, and outcomes of endovascular treatment of DACAA. METHODS: A retrospective review of DACAA endovascularly treated at 5 different institutions was performed. Data included demographics, rupture status, radiographic features, endovascular technique, complication rates, and long-term angiographic and clinical outcomes. A primary endpoint was a good clinical outcome (modified Rankin scale 0-2). Secondary endpoints included complications and radiographic occlusion at follow-up. RESULTS: A total of 84 patients were reviewed. The mean age was 56, and 64 (71.4%) were female. Fifty-two (61.9%) aneurysms were ruptured. A good functional outcome was achieved in 59 patients (85.5%). Sixty (71.4%) aneurysms were treated with primary coiling, and the remaining 24 were treated with flow diversion. Adequate occlusion was achieved in 41 (95.3%) aneurysms treated with coiling, and 17 (89.5%) with flow diversion. There were total 11 (13%) complications. In the flow diversion category, there were 2, both related to femoral access. In the coiling category, there were 9: 5 thromboembolic, 3 ruptures, and 1 related to femoral access. CONCLUSION: Endovascular treatment, and in particular, flow diversion for DACAA, is safe, feasible, and associated with good long-term angiographic and clinical outcomes.

Neuroendovascular Management of Acute Ischemic Basilar Strokes: 2-Dimensional Operative Video.

Basilar artery occlusions (BAOs) are devastating ischemic strokes that account for 1% of all strokes with high morbidity and mortality; however, neuroendovascular techniques such as ADAPT have recently revolutionized the clinical outcomes of these patients.1-3 Common underlying pathology in patients with BAO include intracranial atherosclerotic disease (ICAD) as well as thromboembolic origin.4 Basilar artery ICAD in a setting of acute stroke portends a poor prognosis and post-thrombectomy residual critical flow limiting stenosis treatment options, including balloon angioplasty with or without stent placement.5-7 We present a video illustration of neuroendovascular technique and challenges encountered when managing this pathology. Image at 5:42 reprinted with permission from Alawieh et al, Lessons learned over more than 500 stroke thrombectomies using ADAPT with increasing aspiration catheter size, Neurosurgery, 86(1), 2020, pp. 61-70, with permission from the Congress of Neurological Surgeons.1.

Superior sagittal sinus-to-internal jugular vein bypass shunt with covered stent construct for intractable intracranial hypertension resulting from iatrogenic supratorcular sinus occlusion: technical note.

BACKGROUND: Acute occlusion of the posterior sagittal sinus may lead to dramatic increase in intracranial pressure (ICP), refractory to standard treatment. Hybrid vascular bypass of cranial venous outflow into the internal jugular vein (IJV) has seldom been described for this in recent neurosurgical literature. OBJECTIVE: To describe creation of a novel vascular bypass shunt from the superior sagittal sinus (SSS) to internal jugular vein (IJV) utilizing a covered stent-Dacron graft construct for control of refractory ICP. METHODS: We illustrate a patient with refractory ICP increases after acute sinus ligation that was performed to halt torrential bleeding from intraoperative injury. A temporary shunt was created that successfully controlled ICP. From the promising results of the temporary shunt, we utilized a prosthetic hybrid bypass graft to function as a shunt from the sagittal sinus to IJV. Yet the associated anticoagulation led to complications and a poor outcome. RESULTS: Rapid and sustained ICP reduction can be expected after sagittal sinus-to-jugular bypass shunt placement in acute sinus occlusion. Details of the surgical technique are described. Heparin anticoagulation, while imperative, is also associated with worrisome complications. CONCLUSION: Acute occlusion of posterior third of sagittal sinus carries a very malignant clinical course. Intractable intracranial hypertension from acute sinus occlusion may be effectively treated with a SSS-IJV bypass shunt. A covered stent construct provides an effective vascular bypass conduit. However, the anticoagulation risk can lead to fatal outcomes. The neurosurgeon must always strive for primary repair of an injured sinus.

Endovascular Treatment of Basilar Bifurcation Aneurysms With PulseRider-Assisted Coiling: 2-Dimensional Operative Video.

Wide-necked bifurcation aneurysms pose technical and anatomical challenges to endovascular treatment, which make the simpler assisted (balloon or single stent) coiling techniques less effective.1 Consequently, unique endovascular solutions to treat such aneurysms have been devised.2,3 One such device is PulseRider (Cerenovus, New Brunswick, New Jersey), which is designed to provide neck support for a coil mass while protecting the bifurcation.3 The device comprises a body or stem that is deployed in the parent artery and a saddle component that sits at the aneurysm neck to keep the coil mass away from the bifurcation. There are several technical nuances involved in successful use of the device during positioning, deployment, and detachment.3 We present a surgical video detailing the steps of PulseRider-assisted coiling of unruptured basilar bifurcation (or basilar apex) aneurysms. The first case highlights index treatment at diagnosis and the second showcases treatment of a recurrent basilar apex aneurysm. Both patients provided informed consent to the procedure. We also briefly discuss the rationale for treating basilar apex aneurysms.4,5.

Upper extremity transvenous access for neuroendovascular procedures: an international multicenter case series.

BACKGROUND: Radial artery access for transarterial procedures has gained recent traction in neurointerventional due to decreased patient morbidity, technical feasibility, and improved patient satisfaction. Upper extremity transvenous access (UETV) has recently emerged as an alternative strategy for the neurointerventionalist, but data are limited. Our objective was to quantify the use of UETV access in neurointerventions and to measure failure and complication rates. METHODS: An international multicenter retrospective review of medical records for patients undergoing UETV neurointerventions or diagnostic procedures was performed. We also present our institutional protocol for obtaining UETV and review the existing literature. RESULTS: One hundred and thirteen patients underwent a total of 147 attempted UETV procedures at 13 centers. The most common site of entry was the right basilic vein. There were 21 repeat puncture events into the same vein following the primary diagnostic procedure for secondary interventional procedures without difficulty. There were two minor complications (1.4%) and five failures (ie, conversion to femoral vein access) (3.4%). CONCLUSIONS: UETV is safe and technically feasible for diagnostic and neurointerventional procedures. Further studies are needed to determine the benefit over alternative venous access sites and the effect on patient satisfaction.

Delayed chemical meningitis after Chiari decompression with duraplasty: illustrative cases.

BACKGROUND: Dural reconstruction to achieve expansion duraplasty is important in suboccipital decompression for Chiari malformation type 1 (CM1). Although various dural substitutes are available, including synthetic collagen matrix grafts and dural xenografts, they have the potential to induce an inflammatory response. In this case series, the authors present their experience and discuss the incidence and possible mechanism of aseptic meningitis after the use of bovine collagen matrix graft as a dural substitute in patients with CM1 after suboccipital decompression. OBSERVATIONS: Three consecutive adult female patients who underwent suboccipital decompression at a single institution by a single neurosurgeon were retrospectively reviewed. They all presented with signs of aseptic meningitis in a delayed fashion, responded well to steroid administration, but had recurrence of their symptoms. Bovine collagen dural substitutes are resorbed in a process that induces an inflammatory response manifesting with signs of aseptic meningitis and is only alleviated with removal of the dural substitute. LESSONS: DuraMatrix Suturable, a dural xenograft derived from bovine dermis, though a viable choice for dural repair, is a potential cause of chemical meningitis after duraplasty in Chiari decompression surgery. In patients presenting with delayed and persistent aseptic meningitis after intervention, removal of this dural substitute led to improved symptomatology.

Basilar Artery Perforator Aneurysms and their Contemporary Management.

BACKGROUND: Aneurysms arising in relation to perforators of the basilar artery (basilar perforator aneurysms or BPA) are very rare. Prior literature indicates the need for typically more than one angiogram for diagnosis, and argues for the utility of delayed angiograms in cases of subarachnoid hemorrhage (SAH) with initial negative studies. Different treatment modalities for BPA including endovascular, microsurgical, and conservative management have been described. Contemporary management appears to favor endovascular therapy. We discuss the topic by presenting a case which represents the first instance of BPA diagnosis after a fourth angiogram and subsequent successful endovascular occlusion. A literature review is provided. OBJECTIVE: To discuss the unique presentation and management dilemmas in the rare entity of basilar artery perforator aneurysms by presentation of a case that was managed successfully by endovascular means. We also indirectly highlight the need for multiple follow-up angiograms in initial angiographically negative subarachnoid hemorrhage. METHODS AND MATERIALS: We describe a 62-year-old male presenting with good clinical grade SAH and three negative angiograms, whose hospital course was complicated by repeat intraventricular hemorrhage. A fourth angiogram revealed a BPA. Multiple overlapping stents placed in the basilar artery achieved successful aneurysm exclusion. A comprehensive review of the literature was performed on PubMed. RESULTS AND CONCLUSIONS: Only 57 cases of BPAs have been described in literature. Multiple angiograms may be necessary for diagnosis. These aneurysms present with SAH. Endovascular flow modification is the current treatment of choice by means of overlapping stents or flow diversion.

Illustrated Guide to the Transradial Approach for Neuroendovascular Surgery: A Step-by-Step Description Gleaned From Over 500 Cases at an Early Adopter Single Center.

BACKGROUND: Traditionally, neuroangiography for diagnosis and therapy has been achieved via the transfemoral route. Femoral access, however, has been associated with catastrophic complications. Although transradial access (TRA) has been adopted late by the field of neuroendovascular surgery, several groups have recently demonstrated a dramatically safe and rapid learning curve with a radial-first approach. However, there is a need for a detailed illustrative approach on the transradial technique. OBJECTIVE: To provide a detailed description of the operative technique with step-by-step illustrations derived from our single center series of 506 cases, as an early adopter. METHODS: A step-by-step illustrated approach to our technique of transradial angiography is provided, based on our clinical experience of an early radial-first approach. Prospective review of patients undergoing transradial angiography and interventions from April 1 to November 30, 2019, at our institution was performed. We included all cases that received radial-first arterial access for diagnostic and interventional neuroangiography. Efficacy, complications, catheter use, and radiation metrics of TRA for the entire cohort were noted. The radial approach was described in 4 stages beginning from the wrist (Stage I) and ending with distal access to target vessel of interest (Stage IV). RESULTS: A total of 506 patients underwent TRA over the 7-mo period. Procedural success was achieved in 92.3% of patients (93.7% for diagnostic and 88.5% for interventional). Crossover to the femoral route occurred in 33 (6.5%) cases (25 diagnostic and 8 interventional). The majority occurred in Stage I. No major complications were noted. CONCLUSION: Our preferred technique for the transradial approach provides excellent safety and efficacy in performing diagnostic and interventional neuroangiography. The illustrated technical steps are expected to provide guidance for early adopters of TRA.

Bifurcation Aneurysm Treatment with PulseRider: Technical Nuances, Device Selection, Positioning Strategies, and Overcoming Geometric Challenges.

BACKGROUND: Endovascular therapy is a viable alternative to surgical clipping for the treatment of intracranial aneurysms; however, aneurysms arising at bifurcations remain a challenge. The purpose of this technical report is to share the nuances of treating aneurysms with the PulseRider (PR), including device selection and positioning strategy, from authors who are highly experienced in its use. METHODS: We offer a comprehensive guide for neuroendovascular surgeons less experienced with PR applications to include design, general coil embolization technique, principles of deployment and detachment, positioning options, and geometric challenges and their solutions. RESULTS: In our experience, the PR is well suited for addressing the challenges of treating bifurcation aneurysms. CONCLUSIONS: PR use is intuitive and straightforward for use in bifurcation aneurysms with ideal favorable. PR can also be safely and effectively used to address a much broader and more challenging range of geometries.

Incorporation of transradial approach in neuroendovascular procedures: defining benchmarks for rates of complications and conversion to femoral access.

BACKGROUND: The transradial approach (TRA) has gained increasing popularity for neuroendovascular procedures. However, the experience with TRA in neuroangiography is still in early stages in most centers, and the safety and feasibility of this approach have not been well established. The purpose of this study is to report the safety and feasibility of TRA for neuroendovascular procedures. METHODS: We reviewed charts from six institutions in the USA to include consecutive patients who underwent diagnostic or interventional neuroendovascular procedures through TRA from July 2018 to July 2019. Collected data included baseline characteristics, procedural variables, complications, and whether there was a crossover to transfemoral access. RESULTS: A total of 2203 patients were included in the study (age 56.1±15.2, 60.8% women). Of these, 1697 (77%) patients underwent diagnostic procedures and 506 (23%) underwent interventional procedures. Successfully completed procedures included aneurysm coiling (n=97), flow diversion (n=89), stent-assisted coiling (n=57), balloon-assisted coiling (n=19), and stroke thrombectomy (n=76). Crossover to femoral access was required in 114 (5.2%). There were no major complications related to the radial access site. Minor complications related to access site were seen in 14 (0.6%) patients. CONCLUSION: In this early stage of transforming to the 'radial-first' approach for neuroendovascular procedures, TRA was safe with low complication rates for both diagnostic and interventional procedures. A wide range of procedures were completed successfully using TRA.

Extended Lateral Orbital Craniotomy: Anatomic Study and Initial Clinical Series of a Novel Minimally Invasive Pterional Approach.

Background Of the minimally invasive "keyhole" alternatives to the pterional region, the supraorbital eyebrow approach is the most widely adopted. Yet it can prove disadvantageous when a more direct lateral microsurgical trajectory of attack to the Sylvian fissure and anterior middle fossa are needed. Objective The extended lateral orbital (XLO) approach was designed to be direct and minimally invasive, with the sphenoid ridge at the center of exposure. Methods Five injected cadaver heads were used for anatomic study of the XLO approach. The anatomic course of the frontalis branch of facial nerve was studied in relation to the XLO incision. Following XLO incision, the bone exposure was measured. The intracranial microsurgical exposure was assessed subjectively. Application of the technique in representative clinical operative cases is provided. Results The frontalis nerve was protected in the subgaleal fat pad, with an average minimum distance of 2.3 cm from the XLO incision. The mean calvarial area exposure was 4.95 cm 2 and consistently centered on the sphenoid ridge. Excellent access to ipsilateral Sylvian's fissure, perisylvian regions, and supra-/parasellar structures was possible. The main limitations related to exposure of the posterior Sylvian fissure and the expected limitations of microsurgical instrument manipulation from a smaller craniotomy. Conclusions The XLO approach is a minimally invasive keyhole approach to the pterional region that affords a unique lateral trajectory via a craniotomy centered on the sphenoid ridge. Excellent exposure to properly selected lesions is possible. The incision is at a safe distance from the frontalis branch and shows excellent cosmetic healing.

Fast-track incorporation of the transradial approach in endovascular neurointervention.

BACKGROUND: The transradial approach as a frontline approach is a novel technique in neuroendovascular procedures. In this study we aim to present our early experience with full transition to transradial access as the first-line approach for neuroendovascular procedures. METHODS: We prospectively collected data on the first 100 consecutive patients who underwent a diagnostic or interventional neuroendovascular procedure using the transradial approach at our institution between March 22 and April 30, 2019. Baseline characteristics were collected in addition to the type of procedure, access site, catheters and wires used, complications, and whether there was crossover to transfemoral access. RESULTS: Transradial access was attempted in 121 cases and 91 cases were completed successfully (72 diagnostic procedures and 19 interventional procedures). Mean (SD) age was 56.8 (14.7) years, 54.9% (50/91) underwent the procedure in the outpatient setting, and 60.4% (55/91) were women. Seven patients had minor immediate complications related to the radial access. Interventional procedures successfully performed included aneurysm embolization (ruptured (n=3) and unruptured (n=8)), tumor embolization (n=2), cervical internal carotid artery stenting (n=2), balloon occlusion test (n=1), vertebral artery sacrifice (n=1), and arteriovenous malformation embolization (n=2). CONCLUSION: In this early experience, full transition to the transradial approach as the frontline approach is feasible with a low complication rate for both diagnostic and interventional neuroendovascular procedures.