Faculty Bibliography

Objective/UNASSIGNED:To identify and compare patient and procedural variables that are associated with a high radiation dose exposure and worse clinical outcomes between transradial arterial (TRA) and transfemoral arterial (TFA) approaches. Design/UNASSIGNED:This was a retrospective analysis. Setting/UNASSIGNED:A community hospital during the initial phase of adopting a TRA-first approach. Participants/UNASSIGNED:A resultant 215 subjects who only underwent diagnostic cerebral angiograms (DCA) after excluding all therapeutic procedures and patients under 18 years. Interventions/UNASSIGNED:Only DCA from 1 May 2018 to 31 January 2021. Main outcome measures/UNASSIGNED:We compared radiation exposure parameters (total fluoroscopy time (FT), total radiation dose (TD) and dose area product (DAP), number of vessels injected and Patient-Reported Global Health Physical and Mental Outcome Scores (PROGHS) at 30 days postprocedure between groups. Results/UNASSIGNED:FT was significantly greater in TRA compared with TFA (p<0.001). In addition, TRA had a significantly higher TD (p=0.002) and DAP (p=0.005) when compared with TFA. Analysis of only 6-vessel DCAs also showed that TRA had a significantly higher FT, DAP and TD in comparison to TFA. Despite observing a longer FT in TRA, results showed fewer vessels injected and a notably lower success rate in acquiring a 6-vessel DCA using the TRA. Further analysis of the effect of vessel number on FT using general linear models showed that with every increase of one vessel, the FT increases by 2.2 min for TRA (p<0.001; 95% CI 1.03 to 3.36) and by 1.3 min for TFA (p<0.001; 95% CI 0.72 to 1.83). There was no significant difference between groups in PROGHS mental and physical t-scores at 30 days postprocedure, even though our cohort showed a significantly greater percentage of TRA procedures done in the outpatient setting. Conclusions/UNASSIGNED:Adopting a TRA first approach for DCAs may be initially associated with a higher radiation dose for the patient. Better strategies and devices are needed to mitigate this effect.

Our perspective on anatomy frequently depends on how this anatomy is utilized in clinical practice, and by which methods knowledge is acquired. The thrombectomy revolution, of which the middle cerebral artery (MCA) is the most common target, is an example of a clinical paradigm shift with a unique perspective on cerebrovascular anatomy. This article reviews important features of MCA anatomy in the context of thrombectomy. Recognizing that variation, frequently explained by evolutionary concepts, is the rule when it comes to branching pattern, vessel morphology, territory, or collateral potential is key to successful thrombectomy strategy.

BACKGROUND:Verification of complete occlusion or resection of neurovascular lesions is often done with intraoperative angiography. Surgery for spinal vascular lesions such as arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs) is typically performed in the prone position making intraoperative angiography difficult. There is no standardized protocol for intraoperative angiography in spinal surgeries performed in the prone position. OBJECTIVE:We describe our experience with using radial artery access for intraoperative angiography in thoracic spinal neurovascular procedures performed with patients in the prone position. METHODS:We reviewed all patients who underwent surgical resection of spinal vascular lesions in the prone position with radial artery vascular access for intraoperative angiography. Patients were treated in a hybrid endovascular operating room. RESULTS:4 patients were treated in the pone position utilizing transradial artery access intraoperative angiography for confirmation of complete resection of the vascular lesions. 2 patients were operated for dural AVFs, one patient had a pial AVF, and one patient had an AVM of the filum terminale. None of the patients faced any procedural complications. CONCLUSION/CONCLUSIONS:Radial artery access for intraoperative angiography in spinal neurovascular procedures in which selective catheterization of a thoracic branch is necessary, is feasible, safe, and practical.

Flow diverters (FDs) have changed the management of brain aneurysms; not only for complex aneurysms (giant, fusiform and blister) refractory to conventional therapies, but also for unruptured lesions previously managed by traditional surgical or coil-based endovascular methods. Since 2011 when the PipelineTM Embolization Device (Medtronic) was cleared by the Food and Drug Administration for adults with large or giant wide-neck intracranial aneurysms of the internal carotid artery proximal to the posterior communicating segment, the role of flow diversion for aneurysm treatment has expanded-supported by favorably low complication and high cure rates compared with alternative treatments. Here we review the key clinical trials and the long term outcomes that have demonstrated safety and efficacy of minimized porosity endoluminal devices in the treatment of cerebral aneurysms.

Spinal dural fistulas (SDAVFs) occasionally arise from the same segmental artery as the radiculomedullary branch to the anterior spinal artery. In such cases, selective fistula embolization that does not endanger the anterior spinal artery is not possible, and surgical fistula disconnection is recommended. We present an exceptional case in which rational embolization strategy of SDAVF was feasible because of separate origins from a common segmental artery pedicle of the ventral radiculomedullary artery and the dorsal radicular artery branch supplying the fistula.

Bilateral thalamic strokes due to Artery of Percheron (AOP) occlusion are rare but have been previously reported in the literature. It is due to a rare anatomic variant where a solitary arterial trunk from the proximal segment of either posterior cerebral artery (PCA) supplies bilateral thalami and midbrain. Despite its description in the literature, these strokes are usually missed and patient's symptoms are not thought to be secondary to a vascular etiology. Through this report we aim to describe the clinical and radiographic features seen in these patients. We describe a series of 6 patients who present with varying levels of somnolence and oculomotor nerve palsies who had an occlusion of the AOP with bilateral thalamic infarcts with midbrain involvement. These clinical presentations, combined with the "V" sign on MRI are important in making the diagnosis.

Anatomical vessel obstacles such as an intracranial stenosis in stroke are challenging and may lead to delayed clot access for thrombectomy. We describe a simple and effective technique to overcome the step-off between the intermediate catheter and an intracranial vessel stenosis during thrombectomy. The patient presented with acute embolic left middle cerebral artery occlusion and a favorable penumbral pattern. Clot access was made challenging by focal stenosis in the ipsilateral cavernous segment. The balloon-assisted tracking technique was effective in traversing the step-off to enable TICI 3 aspiration thrombectomy. This simple and effective technique should be kept in mind during stroke procedures where a proximal stenotic obstacle complicates access to the site of occlusion.

Anatomical vessel obstacles such as an intracranial stenosis in stroke are challenging and may lead to delayed clot access for thrombectomy. We describe a simple and effective technique to overcome the step-off between the intermediate catheter and an intracranial vessel stenosis during thrombectomy. The patient presented with acute embolic left middle cerebral artery occlusion and a favorable penumbral pattern. Clot access was made challenging by focal stenosis in the ipsilateral cavernous segment. The balloon-assisted tracking technique was effective in traversing the step-off to enable TICI 3 aspiration thrombectomy. This simple and effective technique should be kept in mind during stroke procedures where a proximal stenotic obstacle complicates access to the site of occlusion.

BACKGROUND: Ischemic arterial strokes of the ophthalmic artery and its branches and posterior cerebral artery are common causes of visual disability. Etiologies of stroke affecting the retina, optic nerve, optic radiation, and visual cortex overlap with other types of ischemic strokes. Stenosis of the internal carotid is the most common cause of central retinal artery occlusion (CRAO). One-fourth of patients with CRAO have cerebral strokes. We report recent developments in the acute treatment and secondary prevention of ischemic stroke of relevance to clinicians who encounter patients with acute vision loss. EVIDENCE ACQUISITION: A search of Pubmed and practice guidelines over the past 5 years was performed, with a focus on significant changes in treatment and prevention of ischemic stroke. RESULTS: Recent randomized controlled trials provide Level I evidence for the use of endovascular therapy with current stent retriever devices for patients with large vessel anterior circulation occlusions within 6 hours of presentation. Number needed to treat to achieve one additional patient with an independent functional outcome was in the range of 3-7, and benefit was additive to that of intravenous tissue plasminogen activator alone. Paroxysmal atrial fibrillation (AF) is a major cause of cryptogenic stroke with incidence expected to rise with the aging population. Since 2014, prolonged 30-day cardiac monitoring has been recommended as a part of transient ischemic attack and stroke workup in patients with cryptogenic stroke. Even longer term monitoring of 6 months to 1 year with external and implantable loop recorders improves rates of diagnosing AF. First available in 2010, the novel anticoagulants-dabigatran, apixaban, rivaroxaban, and edoxaban-have been compared with warfarin in the prevention of stroke in patients with nonvalvular AF. Apixaban demonstrated superiority in safety and efficacy, with the novel anticoagulants as a group having favorable risk-benefit profile at higher dosages compared with standard warfarin therapy. CONCLUSIONS: Endovascular therapy is now standard of care for eligible patients with anterior large vessel occlusions. Prolonged cardiac monitoring is recommended for patients with cryptogenic stroke. The novel anticoagulants are an alternative to warfarin in patients with AF.

We describe two unusual cases of cardiopulmonary death in mechanically ventilated patients in the neurological intensive care unit. After cardiac arrest, both patients were pulseless for a protracted period. Upon extubation, both developed agonal movements (gasping respiration) resembling life. We discuss these cases and the literature on the ethical and medical controversies associated with determining time of cardiopulmonary death. We conclude that there is rarely a single moment when all of a patient's physiological functions stop working at once. This can pose a challenge for determining the exact moment of death.