Back to Authors

Levitt, Michael R

0000-0003-3612-3347

Mayo Clinic

Neurological Surgery, University of Washington School of Medicine, Seattle, Washington, USA.

Citations 39

Carotid In-Stent Stenosis: Cutting Balloon Angioplasty: 2-Dimensional Operative Video

Operative Neurosurgery | June 7, 2021 | Volume: 21 | Issue: 3 | Pages: E240-E241

10.1093/ons/opab194 | PMID 34097735

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.
Crossing the Carotid Siphon: Techniques to Facilitate Distal Access in Tortuous Anatomy: 2-Dimensional Operative Video

Operative Neurosurgery | April 6, 2021 | Volume: 21 | Issue: 1 | Pages: E41-E42

10.1093/ons/opab084 | PMID 33822191

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.
Management of Thromboembolic Complications During Aneurysm Coiling: 2-Dimensional Operative Video

Operative Neurosurgery | February 12, 2021 | Volume: 20 | Issue: 5 | Pages: E348-E349

10.1093/ons/opaa480 | PMID 33571364

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.
Observation Versus Intervention for Low-Grade Intracranial Dural Arteriovenous Fistulas

Neurosurgery | January 14, 2021 | Volume: 88 | Issue: 6 | Pages: 1111-1120

10.1093/neuros/nyab024 | PMID 33582776

Abstract BACKGROUND Low-grade intracranial dural arteriovenous fistulas (dAVF) have a benign natural history in the majority of cases. The benefit from treatment of these lesions is controversial. OBJECTIVE To compare the outcomes of observation versus intervention for low-grade dAVFs. METHODS We retrospectively reviewed dAVF patients from institutions participating in the CONsortium for Dural arteriovenous fistula Outcomes Research (CONDOR). Patients with low-grade (Borden type I) dAVFs were included and categorized into intervention or observation cohorts. The intervention and observation cohorts were matched in a 1:1 ratio using propensity scores. Primary outcome was modified Rankin Scale (mRS) at final follow-up. Secondary outcomes were excellent (mRS 0-1) and good (mRS 0-2) outcomes, symptomatic improvement, mortality, and obliteration at final follow-up. RESULTS The intervention and observation cohorts comprised 230 and 125 patients, respectively. We found no differences in primary or secondary outcomes between the 2 unmatched cohorts at last follow-up (mean duration 36 mo), except obliteration rate was higher in the intervention cohort (78.5% vs 24.1%, P < .001). The matched intervention and observation cohorts each comprised 78 patients. We also found no differences in primary or secondary outcomes between the matched cohorts except obliteration was also more likely in the matched intervention cohort ( P < .001). Procedural complication rates in the unmatched and matched intervention cohorts were 15.4% and 19.2%, respectively. CONCLUSION Intervention for low-grade intracranial dAVFs achieves superior obliteration rates compared to conservative management, but it fails to improve neurological or functional outcomes. Our findings do not support the routine treatment of low-grade dAVFs.
Transarterial Embolization of a Transverse Sinus Dural Arteriovenous Fistula: 2-Dimensional Operative Video

Operative Neurosurgery | December 14, 2020 | Volume: 20 | Issue: 1 | Pages: E41-E42

10.1093/ons/opaa370 | PMID 33316817

Abstract A 40-yr-old male with no significant past medical history presented with sudden onset right-sided retro-orbital headache associated with vision loss after a session of strenuous exercise. Initial assessment with noncontrast head computed tomography at the local emergency department revealed a right sided occipital intracranial hemorrhage (ICH). On arrival the patient ad a left quadrantopsia with Glasgow Coma Scale of 15 and an ICH score of 0. A computed tomographic angiography showed a high density 6 × 9 mm vascular lesion associated with 2 tortuous vessels. Cerebral angiography revealed a right sided dural arteriovenous fistula, Cognard Type IV, with arterial feeders arising from dural branches of the right vertebral artery, the posterior division of the right middle meningeal artery and meningeal branches distal to the neuromeningeal trunk of the left ascending pharyngeal artery. 1 Four days after the ICH event the patient was treated with endovascular Onyx embolization of the fistula, through a transradial approach. Immediate angiographic assessment showed complete obliteration of the dAVF. The patient was discharged home and recovered his visual field deficit over 3 mo. The following operative video includes a discussion of the endovascular technique and treatment nuances associated with the transarterial management of a dural arteriovenous fistula. Patient consent was given prior to the procedure and consent and approval for this operative video was waived due to the retrospective nature of this manuscript and the anonymized video material.
Distal Access to Wide-Necked Aneurysms—‘Around the World’ Technique: 2-Dimensional Operative Video

Operative Neurosurgery | December 14, 2020 | Volume: 20 | Issue: 1 | Pages: E39-E40

10.1093/ons/opaa369 | PMID 33316816

Abstract Wide-necked aneurysms often pose challenges for distal access to the distal vasculature. This 64-yr-old woman without neurological deficits presented with atypical headaches of gradual onset. MRI revealed a large, symptomatic, unruptured carotid terminus aneurysm incorporating the origin of both the middle (MCA) and anterior cerebral arteries (ACA). Its wide neck created significant risks to coil prolapse and parent vessel compromise, risking stroke. With other options of higher risks, we recommended an around-the-world technique. Standard transfemoral access was used to the right internal carotid artery (ICA) with a 6F-Shuttle sheath and intracranial carotid with a 6F-Sofia distal access catheter. With dual-microcatheter access, 1 catheter was placed in the aneurysm dome, a second in the MCA for stent placement. Advancing the wire around the aneurysm first formed a loop from the lateral to medial wall for access to the MCA. The microcatheter was then advanced around the wire into the MCA, keeping the loop within the dome. With the loop's distal tip anchored, the distal end of the stent was deployed and anchored into the MCA. Both pitfalls (ie, lack of sufficient distal access, collapse of stent device during deployment) were resolved using a balloon catheter. With the balloon positioned and inflated as the anchor, the wire and catheter were pulled together. The loop in the aneurysm's dome straightened out across the neck, the stent was advanced into the MCA, and coiling proceeded. A large neck remnant had partially closed on 6-mo follow-up angiogram. Patient consented to undergo the procedure. Illustrations in video published/printed with permission from Mayfield Clinic.
Letter: An International Investigation Into the COVID-19 Pandemic and Workforce Depletion in Highly Specialized Neurointerventional Units – Insights From Stroke Thrombectomy and Aneurysm Registry and Endovascular Neurosurgery Research Group

Neurosurgery | August 24, 2020 | Volume: 87 | Issue: 6 | Pages: E697-E699

10.1093/neuros/nyaa415 | PMID 32893855

Delayed presentation of acute ischemic strokes during the COVID-19 crisis

Journal of NeuroInterventional Surgery | May 28, 2020 | Volume: 12 | Issue: 7 | Pages: 639-642

10.1136/neurintsurg-2020-016299 | PMID 32467244

Background The COVID-19 pandemic has disrupted established care paths worldwide. Patient awareness of the pandemic and executive limitations imposed on public life have changed the perception of when to seek care for acute conditions in some cases. We sought to study whether there is a delay in presentation for acute ischemic stroke patients in the first month of the pandemic in the US. Methods The interval between last-known-well (LKW) time and presentation of 710 consecutive patients presenting with acute ischemic strokes to 12 stroke centers across the US were extracted from a prospectively maintained quality database. We analyzed the timing and severity of the presentation in the baseline period from February to March 2019 and compared results with the timeframe of February and March 2020. Results There were 320 patients in the 2-month baseline period in 2019, there was a marked decrease in patients from February to March of 2020 (227 patients in February, and 163 patients in March). There was no difference in the severity of the presentation between groups and no difference in age between the baseline and the COVID period. The mean interval from LKW to the presentation was significantly longer in the COVID period (603±1035 min) compared with the baseline period (442±435 min, P<0.02). Conclusion We present data supporting an association between public awareness and limitations imposed on public life during the COVID-19 pandemic in the US and a delay in presentation for acute ischemic stroke patients to a stroke center.
Vascular

Operative Neurosurgery | May 17, 2019 | Volume: 17 | Issue: Supplement_1 | Pages: S76-S118

10.1093/ons/opz088 | PMID 31099843