Rangel-Castilla, Leonardo

Craniocervical junction dural arteriovenous fistulas (dAVFs) are rare vascular lesions with a potentially dangerous natural history due to the onset of neurological deficit secondary to intracranial hemorrhage or myelopathy due to venous congestion. Despite advances in endovascular techniques, many dAVFs located in this area continue to require surgical treatment as embolization is often not feasible or safe. In this video, the authors illustrate a patient with a symptomatic craniocervical junction dAVF who had undergone attempted Onyx embolization at another institution. Because of persistent filling of the fistula and worsening myelopathy after the previous attempt, the patient was referred to the authors’ clinic for definitive surgical treatment. The video illustrates the typical location of the early draining vein in most craniocervical junction dAVFs immediately below the emergence of the vertebral artery from the dura. The patient underwent successful definitive clip ligation of the fistula, which was exposed through a lateral suboccipital craniotomy. The video can be found here: https://youtu.be/Bvg6VKLgwO0 .

Purpose: To examine the safety profile of transcervical access (TCA) in comparison with the transfemoral approach (TFA) in carotid artery stenting. Materials and Methods: A systematic review and meta-analysis was performed according to current guidelines. Eleven eligible studies including 11,592 patients (10,736 in the TFA group and 856 in the TCA group) were identified through a search of the PubMed, Scopus, and Cochrane databases up to October 2018. A random effects model meta-analysis was conducted, and the I 2 statistic was used to assess heterogeneity. Publication bias was assessed using funnel plots and quantified using the Egger method. Results: The TFA group had a statistically significantly higher risk of periprocedural (30-day) stroke compared with the TCA group (OR 1.98, 95% CI 1.08 to 3.63, p=0.027; I 2 =0%). Also, patients in the TFA group had a significantly higher risk of developing new ischemic lesions (OR 2.97, 95% CI 1.48 to 5.96, p=0.002; I 2 =0%) on diffusion-weighted magnetic resonance imaging (DW-MRI). No differences in terms of transient ischemic attack (OR 1.50, 95% CI 0.73 to 3.10, p=0.268; I 2 =5.9%), myocardial infarction (OR 0.64, 95% CI 0.30 to 1.35; p=0.242; I 2 =0%), local hematoma (OR 0.53, 95% CI 0.12 to 2.25, p=0.389; I 2 =0%), or mortality (OR 1.35, 95% CI 0.62 to 2.92, p=0.449; I 2 =0%) were identified between the groups. Conclusion: TCA is associated with a significantly lower risk for periprocedural stroke and DW-MRI ischemic lesions compared with TFA. Other periprocedural outcomes were similar between the groups.

Cerebral protection device utilization during carotid artery stenting (CAS) has been demonstrated to decrease the risk of perioperative stroke. The ProximAl Protection with the MO.MA Device During CaRotid Stenting (ARMOUR) Trial had the lowest event rates of any independently adjudicated study. In this video of two cases of severe carotid artery stenosis, the authors present the nuances of the CAS procedure utilizing a dual-balloon guide catheter device (MO.MA). This device has the benefit of being in place before the lesion is crossed with any device, being able to arrest flow while the atherosclerotic lesion is crossed, and aiding in protection from distal emboli and stroke. The video can be found here: https://youtu.be/0o8DlC1n6_M .

Transvenous embolization (TE) has been increasingly applied for arteriovenous malformation (AVM) treatment. Transient cardiac standstill (TCS) has been described in cerebrovascular surgery but is uncommon for endovascular embolization. The authors present a patient with a ruptured thalamic AVM in whom both techniques were applied simultaneously. Surgery was considered, but the patient refused. Transarterial embolization was performed with an incomplete result. The deep-seated draining vein provided sole access to the AVM. A microcatheter was advanced into the draining vein. Under TCS, achieved with rapid ventricular pacing, complete AVM embolization was obtained. One-year magnetic resonance imaging and cerebral angiography demonstrated no residual AVM. The video can be found here: https://youtu.be/CAzb9md_xBU .

OBJECTIVE Sylvian fissure dissection following subarachnoid hemorrhage (SAH) is a challenging but fundamental skill in microneurosurgery, and one that has become increasingly difficult to develop during residency, given the overarching management trends. The authors describe a novel rodent model for simulation of sylvian fissure dissection and cerebrovascular bypass under SAH conditions. METHODS A standardized microvascular anastomosis model comprising rat femoral arteries and veins was used for the experimental framework. In the experimental protocol, following exposure and skeletonization of the vessels, extensive, superficial (1- to 2-mm) soft-tissue debridement was conducted and followed by wound closure and delayed reexploration at intervals of 7, 14, and 28 days. Two residents dissected 1 rat each per time point (n = 6 rats), completing vessel skeletonization followed by end-to-end artery/vein anastomoses. Videos were reviewed postprocedure to assess scar score and relative difficulty of dissection by blinded raters using 4-point Likert scales. RESULTS At all time points, vessels were markedly invested in friable scar, and exposure was subjectively assessed as a reasonable surrogate for sylvian fissure dissection under SAH conditions. Scar score and relative difficulty of dissection both indicated 14 days as the most challenging time point. CONCLUSIONS The authors’ experimental model of femoral vessel skeletonization, circumferential superficial soft-tissue injury, and delayed reexploration provides a novel approximation of sylvian fissure dissection and cerebrovascular bypass under SAH conditions. The optimal reexploration interval appears to be 7–14 days. To the authors’ knowledge, this is the first model of SAH simulation for microsurgical training, particularly in a live animal system.

OBJECTIVE Steno-occlusive diseases of the cerebral vasculature have been associated with cognitive decline. The authors performed a systematic review of the existing literature on intracranial steno-occlusive disease, including intracranial atherosclerosis and moyamoya disease (MMD), to determine the extent and quality of evidence for the effect of revascularization on cognitive performance. METHODS A systematic search of PubMed/MEDLINE, the Thomson Reuters Web of Science Core Collection, and the KCI Korean Journal Database was performed to identify randomized controlled trials (RCTs) in the English-language literature and observational studies that compared cognitive outcomes before and after revascularization in patients with steno-occlusive disease of the intracranial vasculature, from which data were extracted and analyzed. RESULTS Nine papers were included, consisting of 2 RCTs and 7 observational cohort studies. Results from 2 randomized trials including 142 patients with symptomatic intracranial atherosclerotic steno-occlusion found no additional benefit to revascularization when added to maximal medical therapy. The certainty in the results of these trials was limited by concerns for bias and indirectness. Results from 7 observational trials including 282 patients found some cognitive benefit for revascularization for symptomatic atherosclerotic steno-occlusion and for steno-occlusion related to MMD in children. The certainty of these conclusions was low to very low, due to both inherent limitations in observational studies for inferring causality and concerns for added risk of bias and indirectness in some studies. CONCLUSIONS The effects of revascularization on cognitive performance in intracranial steno-occlusive disease remain uncertain due to limitations in existing studies. More well-designed randomized trials and observational studies are needed to determine if revascularization can arrest or reverse cognitive decline in these patients.

Abstract BACKGROUND Flow diversion (FD) is effective for treatment of intracranial internal carotid artery (ICA) aneurysms. OBJECTIVE To determine whether carotid siphon (CS) geometry influences the efficacy of FD when employed for ICA aneurysms. METHODS Outcomes of a consecutive series of patients with ICA aneurysms treated with FD were retrospectively reviewed. CS anatomy was quantified through measurement of the posterior, anterior, and anterosuperior bend angles in accordance with previously described methodology. The relationship of CS geometry to likelihood of incomplete aneurysm occlusion at 1 yr after treatment was assessed with multivariate logistic regression analysis. RESULTS There were 167 ICA aneurysms in 164 patients treated with FD during the study period. The mean age of our cohort was 55.7 yr (standard deviation [SD]: 12.3) and a majority of patients were female (145/164, 86.8%). Anterior (47.4 degrees vs 8.5, P < .001) and anterosuperior bend angles (100.9 vs 76.5, P = .002) were significantly greater in aneurysms that required repeat FD after initial treatment. On multivariate logistic regression analysis, increasing patient age (unit odds ratio [OR]: 1.05, 95% confidence interval [CI] 1.01-1.08; P = .003) and anterior bend angle ≥–3.5 (OR: 2.47, 95% CI 1.04-5.86; P = .046) were associated with increased odds of incomplete aneurysm occlusion at 1 yr after treatment. CONCLUSION These findings suggest that variations in CS anatomy may influence the efficacy of FD treatment and should be analyzed prior to offering FD for treatment of ICA aneurysms. Further investigation into the hemodynamic effects of CS geometry is warranted.

Neuromodulation and deep brain stimulation (DBS) have been increasingly used in many neurological ailments, including essential tremor, Parkinson’s disease, epilepsy, and more. Yet for many patients and practitioners the desire to utilize these therapies is met with caution, given the need for craniotomy, lead insertion through brain parenchyma, and, at many times, bilateral invasive procedures. Currently endovascular therapy is a standard of care for emergency thrombectomy, aneurysm treatment, and other vascular malformation/occlusive disease of the cerebrum. Endovascular techniques and delivery catheters have advanced greatly in both their ability to safely reach remote brain locations and deliver devices. In this review the authors discuss minimally invasive endovascular delivery of devices and neural stimulating and recording from cortical and DBS targets via the neurovascular network.

Abstract We present a case of a patient with pseudotumor cerebri (PC) and transverse/sigmoid junction sinus (TSJS) stenosis treated with stenting venoplasty. A 54-yr-old man with a history of hypertension, hyperlipidemia, and chronic obstructive pulmonary disease presented with subacute onset of progressive headaches, blurred vision, and papilledema. He was clinically diagnosed with PC. Left TSJS stenosis was suspected on magnetic resonance venography and confirmed with digital subtraction angiography and venography. During angiography, venous pressures were measured along the intracranial venous system revealing a significant drop compared with pressures obtained from the superior sagittal and sigmoid sinuses. For 7 d prior to venous sinus stenting, he was prescribed antiplatelet therapy with aspirin (350 mg/d) and clopidogrel (75 mg/d). Patient consent was obtained prior to performing the procedure; institutional board approval is not required for the report of a single case. Under conscious sedation and systemic heparinization, the patient underwent endovascular stenting of the left TSJS with an open-cell carotid stent (Precise 7 × 40 mm; Cordis, Milpitas, California). Successful left TSJS reconstruction transpired with no procedure-related complications. The patient was discharged home 1 d postprocedure. After 2 mo of dual antiplatelet therapy, clopidogrel was discontinued. At the 1-yr follow-up, he had resolution of papilledema and notably less intense headaches. Venous sinus stenting is an effective endovascular treatment for symptomatic patients with PC and sinus stenosis. Venous pressure measurement is imperative for patient selection. Adequate venous access with a 6-French guide catheter into the sigmoid sinus and an intermediate catheter into the transverse sinus is crucial to navigate a stent through the acute angles of the TSJS and jugular vein.