Endovascular middle cerebral artery embolic stroke model: a novel approach

A video (video 1) describing a novel murine endovascular embolic stroke model is presented. Traditional middle cerebral artery (MCA) occlusion models include a blind insertion of a monofilament string12 into the common or external carotid artery with the expectation to selectively occlude the MCA. However, significant mortality occurs due to subarachnoid hemorrhage and variability in stroke size, possibly related to the filament’s malposition—for example, external carotid or proximal internal carotid artery (ICA). Additionally, while the string is in place, it occludes the entire extracranial ICA affecting also the collateral pial circulation.Video 1Our model includes tail artery access, which tolerates several procedures facilitating survival studies. This model uses autologous blood3 4 clot deployed directly into the MCA, resembling what occurs in clinical practice. Autologous thrombi could be lysed with IA/IV tissue plasminogen activator.In summary, we describe a novel model that resembles real practice, permits multiple catheterizations, results in reliable embolization under fluoroscopic guidance and allows therapeutic interventions not available with traditional models.

Multimodal ultrasound parameters aided carotid plaque risk stratification in patients with asymptomatic carotid stenosis

Background Risk stratification of asymptomatic carotid plaque remains an issue in stroke prevention in clinical practice. Purpose To investigate whether a multimodal ultrasound (MMU) model would help plaque risk stratification in patients with asymptomatic carotid stenosis. Material and Methods A prospective study was conducted of symptomatic and asymptomatic patients with > 50% proximal internal carotid artery (ICA) stenosis. All patients underwent MMU examination. Multivariable regression analyses were performed to identify parameters associated with ischemic vascular events (IVE). These parameters were used to develop a scoring nomogram to assess the probability of IVE. We elaborated the diagnostic performance of the MMU nomogram using receiver operating characteristic (ROC) curves. Results From December 2018 to December 2019, 98 patients (75 men, mean age 67 ± 8 years) were included; 50 were symptomatic and 48 were asymptomatic. Multivariable regression analyses revealed that plaque surface morphology (PSM) (odds ratio [OR] 2.99, 95% confidence interval [CI] 1.26–7.12, P = 0.013), intraplaque neovascularization (IPN) grades (OR 3.23, 95% CI 1.77–5.89, P<0.001), and carotid stenosis degree (CSD) (OR 4.12, 95% CI 1.47–11.55, P = 0.007) were independently associated with IVE. For the nomogram, the area under the ROC curve was 0.85 (95% CI 0.77–0.92) and the Hosmer-Lemeshow test P value was 0.822. Conclusions In patients with proximal ICA > 50%, PSM, IPN grades, and CSD were independent variables associated with IVE. The MMU nomogram provided favorable value to risk stratification of IVE. Future large-scale studies with long-term follow-up are needed to validate these findings.

Ultrasound Detection of Extracranial Carotid Artery Aneurysms: A Case Report

The ultrasound definition of extracranial carotid artery aneurysms (ECCAs) is unclear. The threshold diameter to use for defining an extracranial carotid artery as aneurysmal is still debated. Similarly, the ultrasound method of choice for measuring the maximum diameter of ECCAs has not been agreed. In this paper we report the case of a patient with a fusiform aneurysm at the level of the carotid artery bifurcation and a large saccular aneurysm of the proximal internal carotid artery, and discuss the information essential to acquire when ECCAs are detected with ultrasound.

Proximal Internal Carotid artery Acute Stroke Secondary to tandem Occlusions (PICASSO) international survey

BackgroundWhile mechanical thrombectomy (MT) is the standard of care for large vessel occlusion strokes, the optimal management of tandem occlusions (TO) remains uncertain. We aimed to determine the current practice patterns among stroke physicians involved in the treatment of TO during MT.MethodsWe distributed an online survey to neurovascular practitioners (stroke neurologists, neurointerventionalists, neurosurgeons, and radiologists), members of professional societies. After 2 months the site was closed and data were extracted and analyzed. We divided respondents into acute stenting and delayed treatment groups and responses were compared between the two groups.ResultsWe received 220 responses from North America (48%), Latin America (28%), Asia (15%), Europe (5%), and Africa (4%). Preferred timing for cervical revascularization varied among respondents; 51% preferred treatment in a subsequent procedure during the same hospitalization whereas 39% preferred to treat during MT. Angioplasty and stenting (41%) was the preferred technique, followed by balloon angioplasty and local aspiration (38%). The risk of intracerebral hemorrhage was the most compelling reason for not stenting acutely (68%). There were no significant differences among practice characteristics and timing groups. Most practitioners (70%) agreed that there is equipoise regarding the optimal endovascular treatment of cervical lesions in TO; hence, 77% would participate in a randomized controlled trial.ConclusionsThe PICASSO survey demonstrates multiple areas of uncertainty regarding the medical and endovascular management of TOs. Experts acknowledged the need for further evidence and their willingness to participate in a randomized controlled trial to evaluate the best treatment for the cervical TO lesion.

Is flow diversion the death of simple coiling or stent-assisted coiling? A single center experience

Background:: Since the introduction of endovascular methods to treat cerebral aneurysms, several technical advances have allowed a greater number of aneurysms to be treated endovascularly as opposed to open surgical clipping. These include flow diverting stents, which do not utilize coils and instead treat aneurysms by acting as an “internal bypass.” We sought to investigate whether flow diversion is replacing coiling at our institution. Methods:: A retrospective chart review on five years of data was conducted to investigate possible increasing use of flow diversion devices compared to traditional simple or stent-assisted coiling. Results:: Over five years, population revealed a trend toward increased proportion of female patients, increased frequency of basilar tip and internal carotid artery (ICA) aneurysm location, increased hospital volume, and increased volume of patients treated by dual-trained neurosurgeons over interventional radiologists. Patients were stratified by aneurysm location and statistically significant differences were observed. Flow diversion devices were used with increasing frequency when treating aneurysms arising from the proximal internal carotid artery (Odds ratio (OR)=1.24, 95% CI: 1.02-1.50; p = 0.03), and middle cerebral artery (OR=2.60, 95% CI: 1.38-4.88; p = 0.003). Distal internal carotid artery aneurysm location came close to achieving statistical significance (OR=1.3, 95% CI: 0.99-1.72; p = 0.063). Conclusion:: In our single center experience at Houston Methodist Hospital, flow diversion devices are being used more frequently for aneurysms arising from the proximal ICA, MCA, and likely distal ICA (though this third location barely failed to achieve statistical significance.

Dual SAVE technique for mechanical thrombectomy rescue on MCA bifurcation clots

The Stent retriever Assisted Vacuum-locked Extraction (SAVE) technique in mechanical thrombectomy consists of the simultaneous use of a stent retriever and a distal aspiration catheter, with the removal of both as a unit when performing the thrombectomy pass. This is a safe procedure that provides a high rate of first-pass reperfusion.1 In the distal M1 segment of the middle cerebral artery (MCA) occlusions, with the distal portion of the clot extending to the upper and lower MCA branches, mechanical thrombectomy can be challenging since the thrombus is not fully trapped, with risk of distal clot migration to the branch in which the retriever is not placed. In these cases the double stent-retriever technique has been described as a rescue strategy.2–4 We describe a case of the combined use of SAVE and double stent-retriever techniques as a rescue strategy in a patient with tandem occlusion of the proximal internal carotid artery and distal MCA—the D-SAVE technique. (video 1)

Change in the angle of the anterior genu is associated with occlusion rate after Pipeline flow diversion

OBJECTIVEThe Pipeline embolization device (PED) is a self-expanding mesh stent that diverts blood flow away from an aneurysm; it has been successfully used to treat aneurysms of the proximal internal carotid artery (ICA). PEDs have a remarkable ability to alter regional blood flow along the tortuous segments of the ICA and were incidentally found to alter the angle of the anterior genu after treatment. The authors quantified these changes and explored their implications as they relate to treatment effect.METHODSThe authors retrospectively reviewed cases of aneurysms treated with a PED between the ophthalmic and posterior communicating arteries from 2012 through 2015. The angles of the anterior genu were measured on the lateral projections of cerebral angiograms obtained before and after treatment with a PED. The angles of the anterior genu of patients without aneurysms were used as normal controls.RESULTSThirty-eight patients were identified who had been treated with a PED; 34 (89.5%) had complete obliteration and 4 (10.5%) had persistence of their aneurysm at last follow-up (mean 11.3 months). After treatment, 32 patients had an increase, 3 had a decrease, and 3 had no change in the angle of the anterior genu. The average measured angle of the anterior genu was 36.7° before treatment and 44.3° after treatment (p < 0.0001). The average angle of the anterior genu of control patients was 43.32° (vs 36.7° for the preoperative angle in the patients with aneurysms, p < 0.057). The average change in the angle of patients with postoperative Raymond scores of 1 was 9.10°, as compared with 1.25° in patients with postoperative Raymond scores > 1 (p < 0.001).CONCLUSIONSTreatment with a PED significantly changes the angle of the anterior genu. An average change of 9.1° was associated with complete obliteration of treated aneurysms. These findings have important implications for the treatment and management of cerebral aneurysm.

Carotid Body Baroreceptor Preservation and Control of Arterial Pressure in Eversion Carotid Endarterectomy

The technique of the eversion carotid endarterectomy (ECEA), as an alternative to the conventional endarterectomy with primary or patch angioplasty, is an established technique for managing internal carotid artery stenoses and recently its application has been upgraded through the European Society for Vascular Surgery guidelines (Recommendation 55: Class 1, Level A). However, the typical eversion method has been associated with postoperative hypertension due to loss of the baroreceptor reflex; the standard oblique transection at the bulb performed in the eversion endarterectomy interrupts either the baroreceptor sensoring tissue, which is mostly located in the adventitia at the medial portion of the proximal internal carotid artery, or even the proper Hering nerve, a branch of the glossopharyngeal nerve. These actions deregulate the natural negative feedback of the carotid baroreceptor. Guided by the anatomical location of the baroreceptor sensor we have elaborated a slight modification of the classical ECEA to maintain as much as possible of the viable carotid baroreceptor sensoring surface. By extending the oblique incision distal to the carotid bifurcation in the medial part of the internal carotid artery stem, an eyebrow-like part of the proximal internal carotid artery is maintained and the axis from the sensoring tissue to the nerve of Hering is protected and following the endarterectomy, postoperative arterial blood pressure levels are lower than in the classical ECEA due to the maintenance of the efficiency of the baroreceptor reflex. During the period from September 2016 to November 2018, carotid endarterectomy was performed in 57 patients. Twenty-eight of them underwent the typical ECEA and 29 patients had the modified eyebrow eversion carotid endarterectomy (me-ECEA). The changes of blood pressure baseline during the postoperative course in ECEA and me-ECEA group were analyzed and compared. Postoperative hypertension was defined as an elevation of systolic blood pressure (SBP) greater than 140 mm Hg. Patients who underwent typical ECEA had significantly higher postoperative blood pressure values compared with those who underwent me-ECEA. Actually, the mean postoperative SBP was 172.67 ± 24.59 mm Hg in the typical ECEA group compared with 160.86 ± 12.83 mm Hg in the me-ECEA group (p = 0.023). The mean diastolic blood pressure in the ECEA group was 65.42 ± 11.39 mm Hg compared with 58.06 ± 9.06 mm Hg in the me-ECEA group (p = 0.009). Our proposed me-ECEA technique seems to be related to lower rates of postoperative hypertension compared with the typical ECEA, probably due to the sparing of the main mass of the baroreceptor apparatus; this improved modification (me-ECEA) of the typical eversion procedure could represent an alternative ECEA technique with its inherent advantages.

Surgical treatment of a patient with stent restenosis in the mouth of the general carotid artery and the proximal department of the internal carotid artery

<p>The results of surgical intervention on a patient with stent restenosis at the mouth of the common carotid artery (CCA) and proximal internal carotid artery (ICA) are presented herein. In 2013, the patient underwent stenting of the CCA and ICA. One month later, the aortic valve was replaced with a mechanical prosthesis MedEng-23 (MedEng, Penza, Russia) and mammarocoronary anastomosis with an envelope artery was performed under extracorporeal circulation. After the intervention, the patient regularly received 3.75 mg of warfarin, and was under the observation of a cardiologist. In 2018, the patient suffered a transient ischaemic attack. Subsequent examination of the patient revealed sub-occlusion of the left subclavian artery and signs of vertebral–subclavian steal syndrome on the left, and confirmed patency of the mammarocoronary shunt in envelope artery. The patient underwent carotid–subclavian shunting using the BASEX (A.N. Bakulev National Medical Research Center of Cardiovascular Surgery, Moscow, Russia) (8-mm prosthesis. Nine months after the patient underwent carotid–subclavian shunting, 85% restenosis was observed in the stent of the left ICA using control multi-spiral computed tomography with angiography (MSCT AG). The patient also exhibited up to 94% restenosis of the stent of the left ICA, occlusion of the right ICA, and up to 81% stenosis of the proximal anastomosis of the carotid–subclavian shunt. The patient underwent surgery for the removal of the following: the stent from the ICA with endarterectomy from the CCA, ICA with arterial plastic patches from the xenopericardium and prosthesis on the left (8-mm Vascutek prosthesis, Vascutek Ltd., UK). The brain was protected by raising the patient’s systemic blood pressure to 180/90 mm Hg. During the postoperative period, MSCT AG was performed to image the ICA. The MSCT AG images indicated that the prosthesis was passable. Presently, no clear standards exist for achieving revascularisation in this category of patients. The present clinical case emphasised the requirement for the detailed observation of patients after reconstructive interventions in different arteries as well as the possibility of surgically correcting the revealed lesions.</p><p>Received 13 August 2019. Revised 8 November 2019. Accepted 9 November 2019.</p><p><strong>Funding:</strong> The study did not have sponsorship.</p><p><strong>Conflict of interest:</strong> Authors declare no conflict of interest.</p><p><strong>Author contributions</strong><br />Drafting the article: A.N. Kazantsev<br />Literature review: R.Yu. Lider<br />Illustrations: A.R. Shabayev, A.N. Volkov<br />Critical revision of the article: N.N. Burkov, A.I. Anufriyev<br />Preoperative patient preparation: A.R. Shabayev, E.V. Ruban<br />Postoperative care: A.N. Volkov<br />Neurological examination: E.V. Ruban<br />Final approval of the version to be published: A.N. Kazantsev, N.N. Burkov, A.R. Shabayev, A.N. Volkov, E.V. Ruban, R.Yu. Lider, A.I. Anufriyev</p>

De novo formation of a carotid web: case report

A carotid web is a shelf-like intraluminal filling defect typically arising from the posterolateral wall of the proximal internal carotid artery. It is recognized as a possible cause of ischemic stroke in young adults. However, its etiopathogenesis is controversial and remains to be fully elucidated. The authors report de novo formation of a carotid web from an intimal dissection documented on serial imaging studies. The findings in this case suggest that a focal intimal dissection could be the underlying cause of a carotid web. Lower shear stress at the posterolateral wall of the proximal internal carotid artery is hypothesized to be a predisposing factor and explains the predilection of a carotid web for this specific location.