Left Distal Transradial Approach for the Treatment of a Sacral Extradural Arteriovenous Fistula: 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 is 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.

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.

Abstract WP177: Long-Term Outcome of Balloon Angioplasty and Stenting for Symptomatic Intracranial Atherosclerotic Stenosis: Comparison Between Pre- and Post-Approval of Wingspan Stent

Purpose: Intracranial atherosclerotic stenosis (ICS) is an important cause of ischemic stroke, particularly in the Asian population. Endovascular treatment, such as balloon angioplasty with and without stenting have emerged as therapeutic options for symptomatic (ICS) since the 1990s and the Wingspan stent was approved at 2014 in Japan. This study was to investigate the periprocedural complication rates, long-term outcome and restenosis of endovascular treatment for ICS in our hospital.

Methods: We retrospectively analyzed the clinical data of 223 patients with 265 endovascular treatments for high-grade (more than 70%) symptomatic ICS between 1999 and 2017. The lesion was located in in the internal carotid artery in 79, the middle cerebral artery in 113, the basilar artery in 29 and the vertebral artery in 42. Patients were classified into two groups, before (A group, between 1999 and 2013) and after approval of Wingspan (B group, between 2014 and 2017). We selected mainly balloon angioplasty without stenting in the primary treatment. Perioperative and long-term outcomes such as restenosis and the recurrence of strokes were assessed.

Results: In A group (n=163, aged 63.5±10.2 years), 157 lesions were treated with balloon angioplasty and 31 (16.5%) with coronary stent. In B group (n=60, aged 66.4±13.3 years), 39 lesions were treated with balloon angioplasty and 38 (49%) with Wingspan stent. Overall technical success rates were 96% in balloon angioplasty and 100% in stenting groups. The 30-day rate of stroke, TIA and death were 4.3% in A group and 3.9 % in B group. In B group, there was one patient who had subacute in-stent thrombosis with major stroke and 2 minor strokes. There were no stroke and vascular events during follow-up periods in B group. Eight patients (13%) in B group had restenosis after the procedure and 7 patients were retreated.

Conclusions: This study demonstrates the safety and efficacy of balloon angioplasty with and without stenting for symptomatic intracranial atherosclerotic stenosis if patients are properly selected. We suggest that a more judicious use of intracranial stents may be responsible for better postprocedure outcome.

Abstract WP91: Influence of Patient Age on Appearance and Enlargement of DWI Abnormal Lesion After Successful Recanalization by Mechanical Thrombectomy for Acute Ischemic Stroke

Introduction: We have often experienced that young patients tend to have good outcome even with low DWI ASPECTS after mechanical thrombectomy for acute ischemic stroke. As a cause of this phenomenon, we made hypothesis that the appearance of DWI abnormal lesion was influenced by patient age. In this study we aimed to examine the influences of age on appearance of DWI abnormal lesion, and on its enlargement after successful recanalization by mechanical thrombectomy for large-vessel occlusion.

Methods: This study included 94 acute cardioembolic stroke patients who successful recanalization (TICI2b or 3) was obtained with mechanical thrombectomy for large-vessel occlusion in our hospital from 2010 to 2018. Patients were classified into 3 groups depending on age, under 69 years old (Young group, n=20), 70 to 84 (Intermediate group, n=50), and over 85(Elderly group, n=24). DWI abnormal lesion volume was assessed before and within24hours after treatment for each group.

Results: There was no difference in time from onset to recanalization between three groups. Initial DWI abnormal lesion volume in Young group was larger than that in Elderly group (51.0ml vs 10.8ml P<0.05). A similar tendency was observed regardless of the occluded blood vessel site and MRI imaging time and baseline NIHSS. The proportion of patients with the volume of DWI abnormal lesion enlarged 1.5 times or more in 24 hours after treatment in the elderly group was higher than in young group (45% VS 70.8%). In multivariate analysis, the elderly age and the time to reperfusion were related to expansion of DWI abnormal lesion, and this tendency was remarkable in ICA, MCA occlusion.

Conclusions: Young age was associated with the appearance of larger initial DWI abnormal lesions.And old age was associated with the expansion of DWI abnormal lesions after successful recanalization by mechanical thrombectomy of large vessel occlusion.

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.

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.

Abstract TP10: Endovascular Treatment for Acute Ischemic Stroke With Intracranial Atherosclerotic Occlusive Disease

Background: Treatment strategy for acute ischemic stroke with intracranial atherosclerotic disease remains unknown. The aims are to evaluate whether revascularization rates, procedural complications, functional outcomes in patients with emergent endovascular treatment for intracranial atherosclerotic occlusive disease.

Methods: A retrospective review of emergent endovascular treatment from 2003 to 2016 was carried out for acute ischemic stroke patients who had intracranial atherosclerotic occlusion or severe stenosis. Patients were underwent endovascular treatment which included intra-arterial thrombolysis, balloon angioplasty and stenting. Intracranial atherosclerotic disease was defined as significant focal stenosis at the occlusion site, which was evident on final angiographic assessment or observed during endovascular treatment.

Results: A total of 58 consecutive patients were identified. Forty-five were male (78%) and the mean age was 68 years. Atherosclerotic arteries were 24 in middle cerebral artery, 8 in internal carotid artery, 22 in basilar artery, and 4 in vertebral artery. Successful recanalization (TICI 2b and 3) was observed in 45 patients (78%). Intra-arterial thrombolysis, balloon angioplasty without stenting, and balloon angioplasty with stenting by coronary stents were performed in 31 patients (53%), in 45 patients (78%), and in 19 patients (33%), respectively. Acute in-stent thrombosis was observed in 4 patients. Stent retriever and Penumbra system were used in 5 patients and 9 patients, respectively. The postprocedural hemorrhagic complication was observed in 5 patients (8.6%). The incidence of good outcome (90-day modified Rankin scale ≤2) were 68% in anterior circulation and 38% in posterior circulation.

Conclusion: Our data suggest that emergent endovascular treatment for patients with intracranial atherosclerotic occlusive disease is safe and feasible. Particularly, balloon angioplasty with or without stenting have a high rate of recanalization and favorable outcome.

Abstract WP60: Evaluation of Tissue Reversibility by Relative Apparent Diffusion Coefficient Value in Acute Ischemic Stroke Patients Treated With Successful Thrombectomy

Background: By recent advance of endovascular thrombectomy, we have often experienced acute ischemic patients who have diffusion weighted imaging (DWI) reversal lesions after earlier successful recanalization. We retrospectively investigated the relationship between apparent diffusion coefficient (ADC) thresholds of tissue infarction and time from onset to recanalization in acute ischemic stroke patients.

Methods: We assessed 24 patients who have occlusion of internal carotid artery (n=11) and the main trunk of middle cerebral artery (n=13) and obtained recanalization of TICI2b (n=12) and TICI3 (n=12) by thrombectomy and performed MRI before and after treatment. Relative ADC (rADC) value were calculated for initial DWI lesions and around hypoperfused regions. We evaluated rADC values in infarcted and non-infarcted area and analyzed the relationship between rADC thresholds of tissue infarction and time.

Results: The mean time from onset to recanalization was 209 minutes and mean initial NIHSS was 15.4. The mean rADC value was 0.633 in infarcted lesions and 0.905 in non-infarcted area (p<0.001). The thresholds for rADC value for infarction by the area under the curve derived from receiver operating characteristic curve analysis were 0.769 in the area which recanalized under 180 minutes form the onset, 0.792 in that from 180 to 240 minutes, and 0.798 in that over 240 minutes.

Conclusion: The estimation of rADC value may be useful in predicting the likelihood of DWI lesion reversal. Marked decreasing of rADC value which is under thresholds of infarction indicated irreversible damage of ischemic tissue regardless of early successful recanalization.

Abstract TMP3: Which is a Better Predictor of Clinical Outcome After Endovascular Thrombectomy, Pre-treatment DWI ASPECTS or CT Perfusion?

Introduction: Optimal imaging before endovascular thrombectomy for large vessel occlusion remains unclear. We compared pre-treatment DWI ASPECTS and CT perfusion (CTP) to identify which imaging better predicted clinical outcome after endovascular thrombectomy.

Methods: Prospectively collected date for consecutive patients treated with endovascular thorombectomy for acute intracranial internal carotid artery or M1 occlusion and underwent both MRI and CTP before endovascular thrombectomy was analyzed retrospectively. CTP maps were assessed for relative values (rCBF, rCBV and rMTT) obtained for the MCA cortical regions. Pre-treatment DWI ASPECTS and each relative CTP values were compared between good clinical outcome group and poor clinical outcome group. Receiver operating characteristic (ROC) curve analysis was performed to determine the most accurate imaging parameter for the prediction of good clinical outcome.

Results: Sixty-nine patients were eligible for this study. Average age was 74.4 years, median NIHSS on admission was 17. The median time from MRI to CTP was 21 minutes. TICI 2B or more recanalization was achieved in 44 patients. Twenty-four patients achieved good clinical outcomes. DWI ASPECTS (9 vs. 6, p=0.003) and rCBV (0.99 vs. 0.83, p=0.017) were significantly higher in the good clinical outcome group. The area under the ROC curve for good clinical outcome was 0.714 for DWI ASPECTS and 0.676 for rCBV. In the patients with TICI 2B or more recanalization, DWI ASPECTS were significantly higher (9 vs. 6.5, p=0.027) and rCBV tended to be higher (1.01 vs. 0.83, p=0.071) in the good clinical outcome group. The area under the ROC curve was 0.693 for DWI ASPECTS and 0.659 for rCBV in the patients with TICI 2B or more recanalization.

Conclusions: DWI ASPECTS and rCBV could predict clinical outcome after endovascular thrombectomy. DWI ASPECTS better predicted clinical outcome than CTP.

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.

Abstract TP20: Prediction of Hemorrhagic Transformation After Endovascular Thrombectomy by Cerebral Blood Volume and Time to Reperfusion

Introduction: Previous studies suggested that low cerebral blood volume (CBV) lesion predicts hemorrhagic transformation after endovascular therapy.

Hypothesis: We assessed the hypothesis that delays in time to reperfusion lead to hemorrhagic transformation on T2*-weighted MRI after endovascular therapy in patients with low CBV obtained from pre-treatment CT perfusion (CTP).

Methods: We retrospectively analyzed 62 consecutive patients with acute ischemic stroke who were obtained successful reperfusion (TICI 2A-3) by endovascular thrombectomy for internal carotid artery or M1 occlusion. CTP maps were assessed for relative CBV (rCBV) values obtained separately for cortical and basal ganglia regions in the MCA territory. The presence of cortical and basal ganglia hemorrhage (either HI or PH) was assessed on T2*-weighted MRI after endovascular therapy. We analyzed the influence of rCBV in each region, CTP-to-reperfusion time and degree of reperfusion on cortical and basal ganglia hemorrhage.

Results: Forty patients developed hemorrhagic transformation. HIs occurred in 16, PH1s in 21, PH2s in 3 and symptomatic hemorrhage in 1 of the patients. rCBV of the cortical region (0.77 versus 0.98, P=0.002) and basal ganglia region (0.64 versus 0.88, P<0.001) were significantly lower in the patients with hemorrhage than in those without. There was no significant difference in CTP-to-reperfusion time between cortical hemorrhage and no cortical hemorrhage groups. However, in the patients with low cortical rCBV (rCBV <0.8) and TICI ≥2b, mean CTP-to-reperfusion time was significantly shorter (70 versus 108 minutes, p=0.021) in the non-cortical hemorrhage group. There was no significant difference in CTP-to-reperfusion time between basal ganglia hemorrhage and non-basal ganglia hemorrhage groups.

Conclusions: Early reperfusion decreases risk of cortical hemorrhage in patients with low cortical rCBV. Low rCBV in basal ganglia region is more predictive of basal ganglia hemorrhage than time to reperfusion.

Abstract T P13: Effect of Pre-treatment Cerebral Blood Volume and Time to Recanalization on Good Clinical Outcomes in Endovascular Thrombectomy

Introduction: Previous studies suggested that faster times to recanalization led to better clinical outcomes in patients after endovascular thrombectomy.

Hypothesis: We assessed the hypothesis that an association between time to recanalization and clinical outcomes depends on cerebral blood volume (CBV) obtained from pre-treatment CT perfusion (CTP).

Methods: In consecutive patients with acute ischemic stroke who were obtained successful recanalization (TICI 2A-3) by endovascular thrombectomy for internal carotid artery or middle cerebral artery M1 occlusion, we retrospectively analyzed the influence on clinical outcome of time to recanalization and relative CBV value (rCBV) evaluated by pre-treatment CTP. The patient population was divided into 3 groups according to rCBV: severe decreased rCBV group (rCBV <0.6), mild decreased rCBV group (rCBV 0.6 to 0.9) and normal rCBV group (rCBV >0.9). In each group, we compared time to recanalization from onset and CTP between good clinical outcome group (modified Rankin Scale score ≤2 at day 90) and poor clinical outcome group (modified Rankin Scale score ≥3).

Results: Fifty-seven patients were eligible for this study. The mean age was 75.3 years and median baseline NIHSS was 17. Nineteen patients (33.3 %) achieved good clinical outcome. In the severe decreased rCBV group, mean time to recanalization from onset and CTP were 192 and 115 minutes, respectively, but no patient had a good clinical outcome. In the mild decreased rCBV group, mean time to recanalization from onset (180 versus 311 minutes, p=0.034) and CTP (102 versus 169 minutes, p=0.007) were significantly shorter in the good clinical outcome group. In the normal rCBV group, no association was found between clinical outcome and time to recanalization from onset (311 versus 313 minutes) and CTP (177 versus 184 minutes).

Conclusions: Early successful recanalization resulted in better clinical outcome in patients with mild decreased rCBV. Severe decreased rCBV did not provide good outcome regardless of early successful recanalization.

Geometrical cross-sectional imaging by a heterodyne wavelength-scanning interference confocal microscope

We developed a heterodyne interference confocal microscope, using wavelength modulation of a laser diode to realize quick separate measurement of the refractive indices and geometrical thicknesses of multiple layers. This microscope requires only a single axial movement of the specimen. We can display the geometrical cross sections of the interfaces and the refractive indices of a three-layered object.

Separation of measurement of the refractive index and the geometrical thickness by use of a wavelength-scanning interferometer with a confocal microscope

An improved system for the separate measurement of the refractive index and the geometrical thickness that constitutes a hybrid configuration of a confocal microscope and a wavelength-scanning heterodyne interferometer with a laser diode is presented. The optical path difference can be measured in less than 1 s, which is 10 times quicker than with the low-coherence interferometry previously used, and with a resolution of 10 microm with a fixed reference mirror. Separate measurement of the refractive index and the geometrical thickness of glass plates was demonstrated by use of the arrangement in place of the low-coherence interferometer used previously.

Simultaneous measurement of thicknesses and refractive indices of multiple layers by a low-coherence confocal interference microscope

We propose a novel technique for simultaneous measurement of layer thicknesses and refractive indices of multiple layers. It is based on a combination of a confocal microscope and low-coherence interferometry. We derived an expression for the geometrical thickness and the refractive index of each layer from both tracing of a marginal ray accepted by a microscope objective and optical path matching conditions. Experimental verification of this method is illustrated by several samples that have a maximum of 13 layers. The geometrical thicknesses and refractive indices thus derived agreed well with those measured by a micrometer or cited from the literature.

[Treatment of chronic retinal artery obstruction with stellate ganglion block and electric acupuncture]

A 56-year-old man (160 cm, 64 kg) having right visual field defect due to obstruction of the central retinal artery for 6 months was treated with stellate ganglion block and electric acupuncture. His visual field improved slightly immediately after preliminary treatment with stellate ganglion block and electric acupuncture judging from perimeter recording and his complaints. Stellate ganglion block on every day and electric acupuncture on every other day were performed for 10 days and there after these treatments were done two times a week. Twenty days after starting the treatment, his visual field improved on his perimeter examination. We discussed that the cause of improvement was activation of slept cone cells which needed more energy for activation than rod cells by increasing retinal blood flow with stellate ganglion block and electric acupuncture. We recommend vasodilating treatments such as stellate ganglion block and electric acupuncture for visual field defect due to obstruction of central retinal artery even in chronic state.