Pandey, Aditya S

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.

Introduction: Recent studies suggest that suction based thrombectomy leads to better recanalization with RBC-rich clots while stent-retrievers perform better with fibrin-rich clots. The ability to determine real-time histology of clots, in the setting of large vessel occlusion (LVO), could potentially lead to improved recanalization and better clinical outcomes while simultaneously reducing procedural costs. There is an unmet need for technology that would allow for accurate assessment of real-time clot histology in LVOs. Hypothesis: Bioimpedance measurements can be used to predict real-time clot histology. Methods: We constructed an in vitro test bed to measure the bioimpedance of clot analogs with different RBC percentages. The test bed includes a cylindrical chamber with a gold electrode embedded at the bottom. A mixture of human RBCs and plasma was injected into the chamber and coagulation was induced by adding calcium chloride solution. After coagulation, another gold electrode was used to sandwich the clot. Both electrodes were connected to an inductance, capacitance, and resistance (LCR) meter and a low-voltage (10 mV) excitation was sent to the clot at 1 to 201 kHz. We fabricated 5 types of clot analogs by mixing human RBCs and plasma with different RBC percentages (10%, 30%, 50%, 70%, and 90%). Clot types were measured 3 times. The Pearson correlation coefficient was calculated and used to evaluate the relationship between clot bioimpedance and RBC percentage. Results and Conclusions: Clot impedance decreases with the excitation frequency and clots with higher RBC percentages had higher impedance at all excitation frequencies (Fig. 1). The impedance was strongly and positively related to the RBC percentage ( r = .996, p = .0004). By minimizing the electrode size and integrating them into catheters, stents, or wires, such technology could inform clinicians of clot composition and guide device selection for optimum recanalization.

Introduction: Suction catheters and stent retrievers are based on the classical paradigm of “en bloc” removal of emboli by generation of tensile forces by vacuum or device withdrawal. However, in this process emboli elongate and fracture leading to fragmentation. Fragments can migrate downstream or remain impacted in the arterial wall resulting in a residual occlusion. Hypothesis: Clot ingestion is biomechanically superior to “en bloc” removal and leads to higher recanalization rates with less complications. Methods: To test this hypothesis, we present a hybrid test bed consisting of pressurized human brains which was developed and validated for large vessel occlusion (LVO) and revascularization. We fabricated 3 types of representative embolus analogs (EAs) (elastic, fragment-prone and stiff) and recreated 105 LVO in twenty-four fresh human brains with the vasculature connected to an hydraulic system to mimic physiological flow and pressures. Recanalization was attempted in 61 LVO cases by Direct Aspiration (DA) using an 068 catheter and in 44 LVO cases combining Stent Retriever with Aspiration (SR+A). Rates of successful recanalization (SR, Grade 2b or higher) and complete recanalization (CR, Grade 2c or higher) were measured. Up to 4 attempts were done before declaring a failure (Grade 2a or lower). Results: DA resulted in 90% of SR, 79% of CR, 61% of first pass SR and 49% of first pass CR. SR+A resulted in 34% of SR, 34% of CR, 23% of first pass SR and 14% of first pass CR. Elastic EA were associated with 88% of SR, 85% of CR, 61% of first pass SR and 52% of first pass CR. Stiff EAs were associated with 64% of SR, 64% of CR, 36% of first pass SR and 36% of first pass CR. Fragment-prone EAs were associated with 64% of SR, 40% of CR, 38% of first pass SR and 21% of first pass CR. Conclusion: Clot ingestion is biomechanically superior to “en bloc” removal and leads to the highest rates of SR, CR and first pass recanalization. DA achieves higher recanalization rates than SR+A. Elastic clots are associated with the highest rates or recanalization, followed by stiff clots and finally by fragment-prone clots.

Abstract Acute ischemic stroke is one of the leading causes of disability and mortality worldwide. There have been significant improvements to the treatment of acute ischemic stroke over the past 5 yr, specifically related to strokes caused by large vessel occlusions. Stent retrievers with and without local aspiration and direct aspiration alone have all been demonstrated as viable treatment options for this patient population. This case represents the surgical technique for direct aspiration for the treatment of large vessel occlusion. A 76-yr-old man presented with right-sided weakness and aphasia. His last known normal was 5 h ago. His NIHSS (National Institutes of Health Stroke Scale) was 18. The noncontrast computed tomography (CT) did not show a significant infarct burden and ASPECTS (Alberta Stroke Program Early CT Score) of 9. CT angiogram demonstrated a left M1 occlusion. The patient was not a candidate for tissue plasminogen activator (tPA) because of time to presentation; however, the patient was deemed to be a candidate for emergent thrombectomy. Consent was obtained per institutional guidelines for the emergent procedure and the video recording. The video demonstrates a direct aspiration thrombectomy technique for the treatment of stroke. The patient successfully underwent direct aspiration thrombectomy with a TICI 3 (thrombolysis in cerebral infarction) recanalization.

Abstract Thromboembolic complications during aneurysm coiling are rare, with higher rates noted in ruptured aneurysms as patients are not usually premedicated with dual antiplatelet therapy. 1,2 Management includes a series of escalating strategies, including medical therapy and intra-arterial thrombolysis. 3-6 Additional strategies include mechanical thrombectomy with suction aspiration and stent retrievers. 3 Intracranial stenting can be used as a last resource, especially in ruptured cases given the need for dual antiplatelets to prevent stent thrombosis. 2 We present the case of a 42-yr-old man with a ruptured left internal carotid artery aneurysm with associated intracranial and intraventricular hemorrhage. The patient was initially presented to an outside facility after he was found in bed unable to speak and with right hemiparesis. The patient consented for surgery and underwent external ventricular drain (EVD) placement for the treatment of obstructive hydrocephalus, followed by diagnostic cerebral angiogram and aneurysm coiling. After the deployment of the last coil, control angiogram showed a small filling defect at the interface between the aneurysm neck and the distal vessel. The patient received intravenous heparin for therapeutic ACT and aspirin load. After progressive enlargement of the thrombus, the patient received intra-arterial glycoprotein (GP) IIB/IIIA inhibitors with a microcatheter positioned proximal to the thrombus. As the thrombus mass continued to enlarge, mechanical thrombectomy with an aspiration catheter was performed twice. Follow-up angiogram 20 min after the second aspiration demonstrated near-complete resolution of the thrombus. The patient recovered from his right hemiparesis, and he was discharged to rehabilitation on POD #21.

Abstract Intracranial atherosclerosis disease (IAD) is the cause of stroke in up to 10% of cases. Symptomatic IAD results mainly from hypoperfusion, embolic phenomenon, and occlusion. Treatment consists of conservative management with aggressive medical treatment, surgery, and endovascular therapy. 1,2 This video is about a 62-yr-old male who presented with left-sided hemiparesis and right gaze preference secondary to an acute ischemic stroke in the right middle cerebral artery (MCA) territory treated initially with tissue plasminogen activator (tPA). Head computed tomography (CT) angiography (CTA) revealed occlusion of the extracranial and cavernous segments of the internal carotid artery (ICA). CT perfusion (CTP) showed hypoperfusion in the MCA territory and magnetic resonance imaging (MRI) revealed multifocal, wedge-shaped areas of restricted diffusion in the right hemisphere. During his hospitalization, he experienced worsening of his symptoms in the setting of hypoperfusion (hypotension). The patient underwent a cerebral angiogram with thrombectomy and submaximal angioplasty (SA). Successful revascularization of the right ICA was obtained. No procedure-related complications occurred, and the patient's neurological exam improved. SA can be as efficient and a safer option than conventional angioplasty or angioplasty and stenting for symptomatic IAD. The patient consented for the procedure and for the video production.