Schirmer, Clemens M.

Abstract 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

Abstract In-stent stenosis has a reported prevalence of 14% to 19% at 1-yr follow-up after carotid stenting and is associated with an increased risk of acute ischemic stroke. 1,2 Risk factors include female sex, diabetes, and dyslipidemia. Cutting balloon angioplasty is a safe and effective treatment modality for the treatment of carotid in-stent stenosis, and alternative treatment options include observation with medical management and placement of another stent. 3,4 The authors present the case of a 61-yr-old man with carotid in-stent restenosis and progressive worsening on serial imaging with ultrasound. The patient had a history of carotid stenting for symptomatic stenosis 6 mo prior and was maintained on aspirin and clopidogrel. In light of the progressive worsening, the in-stent stenosis was confirmed on computed tomography (CT) angiogram. The options were discussed with the patient and he consented for treatment with cutting balloon angioplasty. Final angiogram showed improvement of the luminal diameter with a residual stenosis of 15%. The patient tolerated the procedure well and was discharged home on postoperative day 1. Follow-up ultrasound demonstrated moderate improvement in peak systolic velocities, and the plan is to continue observation with a clinical follow-up and repeat carotid Dopplers at 3 mo.

Abstract Embolic protection devices (EPDs) have become a standard of care during internal carotid artery revascularization. 1,2 This video is about a 57-yr-old-male who presented with a wake-up stroke with a left hemispheric syndrome. Head computed tomography angiography (CTA) revealed tandem occlusions of the proximal left internal carotid artery (ICA) and of the distal left middle cerebral artery (MCA) with an ASPECT (Alberta Stroke Program Early CT Score) score of 6. The patient underwent a cerebral angiogram and was treated with balloon angioplasty with a distal EPD and mechanical thrombectomy. The EPD became occluded with thrombus from the ICA and was retrieved through a 6-Fr Sofia (MicroVention) under continuous aspiration. Successful revascularization of the proximal ICA and distal MCA was achieved. No procedure-related complications occurred, and the patient's neurological exam improved. Tandem occlusions can occur in up to 15% of strokes. The optimal treatment can be controversial, but mechanical thrombectomy and ICA revascularization with a distal EPD appear to be safe and effective in selected patients. 3 Consent was obtained for the procedure and for the video production.

Abstract Intracranial atherosclerotic disease (ICAD) is a common cause of stroke. Antiplatelet therapy is the mainstay for symptomatic ICAD treatment. Endovascular management with submaximal angioplasty and/or intracranial stenting is reserved for patients with repeated ischemic events despite optimal medical therapy. We demonstrate intracranial angioplasty and stenting technique, technique indications, and sizing of stent and target vessel diameter. Stenting and angioplasty have been described in the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis and Wingspan Stent System Post Market Surveillance trials. 1,2 Submaximal angioplasty has also been described. 3 This patient, who had been on dual antiplatelet therapy for several months, initially presented with occlusion of the left middle cerebral artery M2 inferior division and underwent mechanical thrombectomy with successful reperfusion. Postoperatively, the patient's symptoms did not improve. Medical management was optimized with heparin infusion. However, repeat stroke study demonstrated M2 inferior division reocclusion. A decision was made to proceed with intracranial angioplasty and stenting. P2Y12 levels were therapeutic. Under moderate conscious sedation, submaximal angioplasty of up to 80% of the normal M2 caliber was attempted. However, we observed persistent high-grade stenosis of the M2 inferior division. The major risk of crossing the lesion for angioplasty is vessel perforation. To safely perform this maneuver, we used a J-configured Synchro-2 microwire (Stryker). Because of the patient's recent thrombectomy, we also had prior tactile feedback about how much resistance was encountered while crossing the occlusion. We then deployed a balloon-mounted intracranial stent for optimal radial force across the stenotic area to restore perfusion. Postoperative computed tomography perfusion showed resolution of the previously noticed perfusion deficit. The patient gave informed consent for the procedures and video recording. Institutional review board approval was deemed unnecessary. Video. ©University at Buffalo Neurosurgery, September 2020. With permission.

Abstract Vascular access for cerebral angiography has traditionally been performed via the common femoral artery. It is crucial to obtain safe access to prevent complications that could lead to limb ischemia, groin hematoma, or retroperitoneal hematoma. This is especially true in neurointervention as many patients are anticoagulated or have received intravenous thrombolytics prior to their intervention. Special attention to anatomic landmarks, both grossly and radiographically, can help to assure safe access. The patient consented for this procedure. This video details rapid but safe femoral artery access in a patient undergoing emergent thrombectomy.

Abstract Management options for carotid stenosis include medical management, carotid endarterectomy, carotid stenting with distal filter protection, or stenting with either flow arrest or flow reversal techniques. 1 Flow reversal with transcarotid artery revascularization (TCAR) technique represents a hybrid approach with surgical access to the common carotid for endovascular placement of a stent in the internal carotid artery. This direct access to the carotid artery avoids navigating the challenging anatomy of the aortic arch with endovascular devices. 2 Compared to transfemoral stenting, TCAR possesses lower risk of transient ischemic attack and stroke, and compared to carotid endarterectomy, there is less risk of cranial neuropathy. 3,4 We present the case of an 87-yr-old man with recurrent severe stenosis (85%) of the right internal carotid artery. The patient had a remote history of bilateral endarterectomies for asymptomatic stenosis and was found with recurrence and progression of right internal carotid artery stenosis. Options were discussed and decision was made to proceed with TCAR after he consented for the procedure. The patient tolerated the procedure well with satisfactory revascularization. Exam remained unremarkable prior to discharge on postoperative day 1 and during follow-up at 1 mo. Patient consented to the publication of their image.

Abstract Cerebral venous sinus stenting has gained popularity in recent years as a safe and efficacious treatment of selected patients with idiopathic intracranial hypertension (IIH) and focal venous sinus stenosis.1–3 - 3 The main goal of treatment is to prevent visual loss, and often patients report resolution of headache and visual symptoms within 21 mo of mean follow-up.4–8 - 8 We present the case of a 57-yr-old woman with medically refractory IIH, bilateral sinus stenosis, and a mass lesion causing stenosis on the left. Venous angiogram with pressure monitoring was completed with the patient awake, which showed a significant pressure gradient on the right (19 mm Hg) and borderline gradient on the left (8 mm Hg). Options were reviewed and decision was made to proceed with the treatment of the right-sided stenosis with stenting and continue with the observation of the lesion on the left to prevent further visual deterioration. The patient consented for the procedure, and she tolerated the procedure well. Neurological exam remained at baseline, and she was discharged home on post-operative day #1. At 2 mo’s follow-up, the patient reported improvement in headaches and remained intact neurologically.

Abstract 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

Abstract Mechanical thrombectomy as a treatment for large vessel occlusion to achieve rapid revascularization is supported in the literature. 1-3 The presenting symptoms will localize to functions of the ischemic area. The middle cerebral artery (MCA) supplies areas of the frontal, temporal, and parietal cortices, as well as the basal ganglia. Occlusion of the MCA will present with contralateral hemiplegia, sensory loss, and, if the dominant hemisphere is involved, language deficits. We present a right-hand-dominant 79-yr-old female with right MCA syndrome—her last known well time was 1.5 h prior to presentation. Her NIH (National Institutes of Health) Stroke Scale was 16, most notable for left hemiplegia. Although the patient presented early in the clinical time course, as part of our institution protocol, a computed tomography (CT) head, CT perfusion, and CT angiogram (CTA) were performed. CT head did not demonstrate acute hemorrhage, so she received intravenous tissue plasminogen activator. CTA demonstrated a right MCA occlusion and CT perfusion suggested a large area of salvageable tissue, so she was taken to the angiography suite for mechanical thrombectomy. Angiography of the right internal carotid artery (ICA) showed MCA occlusion (insular segment). A thrombectomy device was deployed over the area of occlusion and allowed to engage for 5 min. An aspiration catheter was advanced over the stentriever up against the clot. The stentriever device was withdrawn under continuous aspiration and follow-up angiography showed complete reperfusion. The patient demonstrated improvement and was eventually discharged to an inpatient rehabilitation center. Patient provided consent for photography per university protocol. Institutional review board (IRB) approval was not needed for the single-patient data included in this report.

Abstract As capabilities for endovascular treatment of intracranial vascular pathologies continue to expand, the need for access to the distal internal carotid artery with rigid support catheter systems continues to increase. One of the dominant factors limiting this access is patient anatomy, specifically vessel tortuosity. Increased tortuosity of the carotid siphon is a frequently encountered anatomic variant and may complicate endovascular procedures in adults and children. 1,2 Failed attempts to navigate the carotid siphon with a distal access catheter carry a risk of vessel injury and treatment failure. For this reason, techniques that aid in supporting safe advancement of a distal access catheter across a tortuous carotid siphon are essential. 3,4 In this video, we demonstrate 2 ways in which this may be accomplished. The first technique uses a larger diameter microcatheter, such as the AXS Offset catheter (Stryker, Kalamazoo, Michigan), to increase support for the distal access catheter, while the second uses a buddy wire technique to accomplish this increased support. Both of these techniques can help increase the safety of navigating a tortuous carotid siphon and increase the likelihood of successful treatment. The procedures shown were performed with the informed consent of the patients.