Left Distal Transradial Approach for the Treatment of a Sacral Extradural Arteriovenous Fistula: A Technical Note and Literature Review.

BACKGROUND: Sacral extradural arteriovenous fistula (SEAVF) is relatively rare, and its etiology is unknown. They are mostly fed by the lateral sacral artery (LSA). For endovascular treatment, both the stability of the guiding catheter and accessibility of the microcatheter to the fistula, distal to the LSA are required for sufficient embolization of the fistulous point. Cannulation of these vessels requires either crossover at the aortic bifurcation or retrograde cannulation using the transfemoral approach. However, atherosclerotic femoral and tortuous aortoiliac vessels can make the procedure technically difficult. Although the right transradial approach (TRA) can reduce this difficulty by straightening the access route, a potential risk remains for cerebral embolism because it passes the aortic arch. Herein, we present a case of successful embolization of a SEAVF using a left distal TRA. METHODS: We report a case of a 47-year-old man with SEAVF treated with embolization using a left distal TRA. Lumbar spinal angiography showed a SEAVF with an intradural vein through the epidural venous plexus fed by the left LSA. A 6-French guiding sheath was cannulated into the internal iliac artery via the descending aorta using the left distal TRA. A microcatheter could be advanced into the extradural venous plexus over the fistula point from the intermediate catheter placed at the LSA. Embolization with coils and n-butyl cyanoacrylate was successfully performed. RESULTS: The SEAVF completely disappeared on neuroimaging, and the patient gradually recovered. CONCLUSIONS: Left distal TRA could be a useful, safe, and less invasive option for the embolization of SEAVF, especially for patients with high-risk factors for aortogenic embolism or puncture site complications.

Usefulness of carotid duplex ultrasonography in predicting residual large-vessel occlusions after intravenous recombinant tissue plasminogen activator therapy in patients with acute ischemic stroke.

PURPOSE: Endovascular therapy (EVT) preceded by intravenous thrombolysis with recombinant tissue plasminogen activator (iv-rtPA) has been established as a standard treatment in patients with stroke caused by large-vessel occlusion (LVO). Primary stroke centers without EVT competence need to identify patients with residual LVO after iv-rtPA therapy and transport them to an EVT-capable facility. Carotid ultrasonography (CUS) is easily applicable at bed side and useful for detecting extra- and intracranial LVO. This study aimed to determine whether CUS findings at admission are useful to predict patients with residual LVO after iv-rtPA. METHODS: Patients scheduled to undergo iv-rtPA for acute cerebral infarction were registered. Before iv-rtPA, they underwent CUS, followed by CTA or MRA evaluation within 6 h after iv-rtPA. A model that can achieve 100% sensitivity for detecting residual LVO after iv-rtPA was studied. RESULTS: This study included 68 of 116 patients treated with iv-rtPA during the study period. National Institutes of Health Stroke Scale (NIHSS) score (cutoff value = 10) on arrival, hyperdense MCA sign on non-contrast CT, end-diastolic (ED) ratio on CUS, and eye deviation were significantly different between patients with residual LVO after iv-rtPA and those without. If any of these clinical features are positive in the screening test, residual LVO could be predicted with 100% sensitivity, 50% specificity, 64% positive predictive value, and 100% negative predictive value. CONCLUSION: Prediction of residual LVO with 100% sensitivity may be feasible by adding CUS to NIHSS score > 10, the presence of eye deviation, and hyperdense MCA sign.

The Utility of Automated ASPECTS in Acute Ischemic Stroke for Intravenous Recombinant Tissue Plasminogen Activator (IV-rtPA) Therapy.

PURPOSE: This study aimed to investigate the accuracy and clinical significance of an artificial intelligence (AI)-based automated Alberta Stroke Program Early Computed Tomography (ASPECT) scoring software of head CT for the indication of intravenous recombinant tissue plasminogen activator (rt-PA) therapy. METHODS: This study included two populations of acute ischemic stroke: one comprised patients who had undergone head CT within 48 h of presentation (Population #1, n = 448), while the other included patients within 4.5 h from onset (Population #2, n = 132). The primary endpoint was the concordance rate of ASPECTS of the neurologists and AI software against the benchmark score. The secondary endpoints were to validate the accuracy of the neurologist and AI software in assessing the ability to rule out extensive infarction (ASPECTS of 0-5) in population #2. RESULTS: The reading accuracy of AI software was comparable to that of the board-certified vascular neurologists. The detection rate of cardiogenic cerebral embolism was better than that of atherothrombotic cerebral infarction. By excluding extensive infarction, AI-software showed a higher specificity and equivalent sensitivity compared to those of experts. CONCLUSIONS: The AI software for ASPECTS showed convincing agreement with expert evaluation and would be supportive in determining the indications of intravenous rt-PA therapy.

Initial Experience with Left Transradial Neurointerventions for Cerebral Aneurysms Using the 6-French Simmons Guiding Sheath.

OBJECTIVE: The use of a transradial approach utilizing a Simmons-shaped catheter for neurointervention has been steadily increasing. Although the right radial artery is commonly used, in interventional cardiology, the left transradial approach offers clear clinical benefits for right-handed patients. To the best of our knowledge, no previous studies have examined intracranial aneurysm embolization with the routine use of the left transradial approach. The aim of this study was to evaluate the technical feasibility of left transradial intracranial aneurysm embolization. METHODS: We conducted a retrospective review of a prospective database of consecutive patients who had undergone left transradial intracranial aneurysm coiling using a 6-French Simmons guiding sheath between January and August 2021. The following outcome variables were then analyzed: whether the catheterization was successful, the angiographical results, and the presence of any procedure-related complications. RESULTS: In total, 25 patients underwent left transradial coiling for 15 anterior and 10 posterior circulation aneurysms. The Simmons guiding sheath could be successfully shaped and cannulated into the targeted vessel in all patients. All aneurysms were completely embolized without any complications. Immediate postoperative angiograms showed Raymond 1 in 10 aneurysms (40.0%), Raymond 2 in 12 (48.0%), and Raymond 3a in 3 (12.0%). None of the patients required crossover to the right radial or femoral arteries, and no radial artery spasms or occlusions were observed. CONCLUSION: The results of this study suggest that the left transradial approach for intracranial aneurysm coiling is not only safe, effective, and technically feasible, but also provides improved comfort to right-handed patients.

Left Transradial Neurointerventions Using the 6-French Simmons Guiding Sheath: Initial Experiences with the Interchange Technique.

BACKGROUND: The transradial approach using a Simmons-shaped catheter has been increasingly used for diagnostic cerebral angiography and neurointervention. In the transradial approach for neurointervention, the right radial artery is mainly used. However, in interventional cardiology, there are apparent clinical benefits with the left transradial approach for right-handed patients. To our knowledge, no studies have reported on neurointervention with the routine use of the left transradial approach. We therefore devised a novel technique for cases with an unachievable form of the Simmons shape using the standard technique, which we named the "interchange technique." The purpose of this study was to evaluate the technical feasibility of the left transradial neurointervention. METHODS: This study is a retrospective review of our prospective database of consecutive patients who underwent a left transradial neurointervention, using a 6-French Simmons guiding sheath, performed from January through April 2021. The outcome variables studied were successful catheterization and procedure-related complications. RESULTS: Twenty-one patients underwent a left transradial neurointervention including cerebral aneurysm coiling, carotid artery stenting, and meningioma embolization. The Simmons shape could not be formed with the standard technique for 3 patients, for whom we successfully formed the Simmons shape with our new interchange technique. The procedure was completely achieved in all 21 patients. No patients required crossover to the right radial or femoral arteries, and there were no radial artery spasms or occlusions or any procedural complications. CONCLUSIONS: The left transradial approach for neurointervention is a technically feasible, safe, and effective alternative while providing more comfort to right-handed patients.

Contrast-enhanced carotid ultrasonography and MRI plaque imaging to identify patients developing in-stent intimal hyperplasia after carotid artery stenting.

AIM: In-stent intimal hyperplasia (ISH) observed after carotid artery stenting (CAS) may lead to in-stent restenosis. We aimed to investigate whether contrast-enhanced carotid ultrasonography (CEUS) and magnetic resonance imaging (MRI) plaque imaging prior to CAS are predictive for ISH at 6 months after CAS. MATERIAL AND METHOD: A total of 14 patients (13 men, 1 woman; mean age, 74.2 years) were prospectively enrolled. CEUS and MRI plaque imaging were performed before CAS. ISH was diagnosed by carotid angiography at 6 months after CAS. Patients were divided into two groups based on the thicknessof ISH and age, risk factors, enhancement in CEUS, MRI plaque imaging and number of replaced stents were compared between groups. RESULTS: Carotid angiography at 6 months after CAS revealed ISH in 10 patients. Plaque enhancement on CEUS was observed in 6 patients, all of whom showed ISH. A significant association was seen between plaque enhancement on CEUS and development of ISH (χ2 test, CEUS enhancement (+) 100% vs. CEUS enhancement (-) 50% p=0.040). Carotid plaques in 12 patients were diagnosed as unstable by MRI plaque imaging. Presence of ISH was significantly associated with unstable plaque diagnosed by MRI plaque imaging (χ2 test, unstable 83% vs. stable 0%; p=0.016). CONCLUSION: Carotid plaque MRI and CEUS may be useful to predict ISH after CAS.

Contrast-enhanced transoral carotid ultrasonography for the evaluation of plaque protrusion after carotid artery stenting.

A 67 year-old man was admitted to our hospital because of mild left hemiparesis and was diagnosed with cerebral infarction caused by right internal carotid artery stenosis. He was treated with dual antiplatelet therapy and scheduled for carotid artery stenting 14 days after onset. The preoperative right carotid angiogram showed 60% stenosis by the NASCET criteria, with an ulcer. The postoperative angiogram suggested protrusion in the stent, which could not be seen on conventional carotid ultrasonography because of its high location. On transoral carotid ultrasonography, clear delineation of the lesion was not possible due to color blurs. Contrast-enhanced transoral carotid ultrasonography (CETOCU) clearly demonstrated the protrusion and delineated the lumen within the stent.

Long-Term Outcome of Balloon Angioplasty Without Stenting for Symptomatic Middle Cerebral Artery Stenosis.

PURPOSE: A recent randomized controlled trial demonstrated that aggressive medical management was superior to angioplasty with stenting for intracranial stenosis. The purpose of this study was to assess initial and long-term outcomes of balloon angioplasty without stenting for symptomatic middle cerebral artery (MCA) stenosis. METHODS: We retrospectively analyzed the clinical data of 72 patients (mean age, 58.9 years old) with 84 balloon angioplasties without stenting for high-grade (>70%) atherosclerotic stenosis of the main trunk of the MCA. All patients had experienced recurrent transient ischemic attack or minor stroke resistant to medical treatment. We assessed perioperative and long-term outcomes such as restenosis and the recurrence of strokes. The follow-up period was a median of 63 months (range, 6-171 months). RESULTS: Balloon angioplasty was successful in 97% of procedures. During the 30-day perioperative period, a total of 3 patients suffered from stroke (4.2%) without death. A total of 23 (31.9%) patients had restenosis at a time point that varied from 6 to 111 months. Diabetes mellitus (DM) was noted significantly more often in the restenosis group (39%) than in the nonrestenosis group (13%). Multivariate logistic regression analysis revealed DM (odds ratio, 4.84; 95% confidence interval, 1.196-19.62; P = .027) as an independent predictor of restenosis. Restenosis and DM were indicated as independent predictors of the recurrence of ischemic stroke and transient ischemic attack. CONCLUSIONS: Balloon angioplasty without stenting for symptomatic MCA stenosis can be performed with a high successful rate and a low risk of complications. Long-term outcome data suggest that this procedure reduces the risk of further strokes.

Effects of Pretreatment Cerebral Blood Volume and Time to Recanalization on Clinical Outcomes in Endovascular Thrombectomy for Acute Ischemic Stroke.

BACKGROUND: Faster time to recanalization leads to better clinical outcomes in patients treated with endovascular thrombectomy. Whether the association between time to recanalization and clinical outcomes depends on cerebral blood volume (CBV) obtained from pretreatment computed tomography (CT) perfusion (CTP) imaging was investigated. METHODS: In consecutive patients with acute ischemic stroke who achieved recanalization by endovascular thrombectomy for intracranial internal carotid artery or M1 occlusion, the effects on clinical outcome of time to recanalization and the relative CBV value (rCBV) assessed by pretreatment CTP were evaluated. The patient population was divided into 2 groups according to rCBV: normal rCBV group (rCBV ≥ .9) and low rCBV group (rCBV < .9). In each group, time to recanalization was compared between the good and the poor clinical outcome groups. RESULTS: Sixty-four patients were eligible for this study. Twenty-six patients (40.6%) achieved good clinical outcomes. In the normal rCBV group, no association was found between clinical outcome and time to recanalization. In the low rCBV group, time to recanalization from CTP (101 minutes versus 136 minutes, P = .040) was significantly shorter in the good clinical outcome group. On binary logistic regression modeling, CTP to recanalization time (odds ratio 1.035 [1.004-1.067], P = .025) was an independent predictor of good clinical outcome only in the low rCBV group. CONCLUSIONS: The association between time to recanalization and clinical outcomes depends on rCBV obtained from pretreatment CTP. Time to recanalization is more important for good clinical outcomes in patients with low rCBV than in patients with normal rCBV.

A case in which contrast-enhanced transoral carotid ultrasonography was useful for pre- and post-procedural evaluation in carotid artery stenting.

Contrast-enhanced transoral carotid ultrasonography (CETOCU) is a novel examination modality that is superior to other modalities in the cases of pseudo-occlusion with severe arteriosclerotic stenosis of the distal internal carotid artery (ICA), and is also useful for noninvasively evaluating changes over time in the vessel distal to the stent following carotid artery stenting (CAS). We report a case of a patient who we evaluated with CETOCU for a pseudo-occlusive ICA before and after CAS.

Contrast-enhanced transoral carotid ultrasonography for the evaluation of a long stenotic lesion in the internal carotid artery.

Contrast-enhanced transoral carotid ultrasonography (CETOCU) is a novel modality for imaging the distal extracranial internal carotid artery, which is not possible with conventional carotid ultrasonography. We present a representative case that demonstrates the usefulness of CETOCU.

Prediction of cerebral hyperperfusion syndrome after carotid artery stenting by CT perfusion imaging with acetazolamide challenge.

INTRODUCTION: Cerebral hyperperfusion syndrome (HPS) is an uncommon but serious complication of carotid artery stenting (CAS). The purpose of this study was to investigate the efficacy of CT perfusion imaging (CTP) with acetazolamide challenge to identify patients at risk for HPS after CAS. METHODS: We retrospectively analyzed 113 patients who underwent CTP with rest and acetazolamide challenge before CAS. CTP maps were assessed for absolute and relative cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and change of each parameter before and after acetazolamide challenge. Patients were divided into two groups according to the HPS after the CAS. Receiver-operating characteristic (ROC) curve analysis was performed to determine the most accurate CTP parameter for the prediction of HPS. RESULTS: Nine of 113 patients had HPS. There were significant differences for absolute and relative values of resting CBF (p = 0.001 and p = 0.026), resting MTT (p < 0.001 and p = 0.004), post-acetazolamide CBF (p < 0.001 and p = 0.001), post-acetazolamide MTT (p < 0.001 and p = 0.002), and % changes of CBF (p = 0.009) between the HPS and non-HPS groups. ROC curve analysis showed that the CTP parameters with the maximal area under the receiver-operating characteristic curve (AUC) for HPS was the absolute value of post-acetazolamide MTT (AUC 0.909) and the absolute value of resting MTT (AUC 0.896). CONCLUSION: Pretreatment CTP with acetazolamide challenge could identify patients at risk for HPS after CAS. Although the CTP parameter that most accurately identified patients at risk for HPS was the absolute value of post-acetazolamide MTT, resting MTT was sufficiently accurate.