Diagnostic Impact of Monitoring Visual Evoked Potentials to Prevent Visual Complications During Endovascular Treatment for Intracranial Aneurysm.

Introduction: The present study aimed to determine the incidence of intraprocedural visual-evoked potential (VEP) changes and to identify correlations with intraprocedural ischemic complications during endovascular treatment in patients with intracranial aneurysm related to visual function. Methods: This study analyzed data from 104 consecutive patients who underwent endovascular coil embolization to treat intracranial aneurysms related to visual function under VEP and transcranial motor evoked potential (MEP) monitoring. We analyzed associations between significant changes in MEP and VEP, defined as a >50% decrease in amplitude, and both intraprocedural complications and postoperative neurological deficits. Factors associated with postoperative neurological deficits were also assessed. Results: Treated aneurysms were predominantly located in the internal carotid artery (95%). Five (5%) were located in the posterior cerebral artery (PCA). Significant decreases in intraprocedural VEP occurred in four patients (4%), although one of those four patients did not show concomitant MEP decreases during procedures. Immediate salvage procedures avoided postoperative visual disturbances. All VEP decreases were transient and not associated with postoperative visual impairment. One of three cases who underwent intraoperative balloon occlusion test showed tolerance to balloon occlusion of the proximal PCA under VEP assessment; parent artery occlusion was performed without postoperative visual disturbance in that case. Conclusion: Although significant VEP decreases occurred 4% during neuro-endovascular aneurysm treatment related to visual function, intraprocedural VEP monitoring identifies ischemic changes associated with visual pathways and facilitates prompt initiation of salvage procedures.

Hypocapnia Induced by Hyperventilation with Indocyanine Green Kinetics Detects the Effect of Staged Carotid Angioplasty to Avoid Hyperperfusion in Patients with Impaired Cerebral Hemodynamic Reserve.

Cerebral hyperperfusion syndrome (CHS) is a serious complication following carotid artery stenting (CAS). Staged angioplasty (AP) could potentially prevent CHS and hyperperfusion phenomenon (HPP) after revascularization. However, methods for measuring the effects of staged AP on cerebral hemodynamic reserve have not been established. Here, we evaluated whether indocyanine green kinetics and near-infrared spectroscopy (ICG-NIRS) with hypocapnia induced by hyperventilation can detect the effects of staged AP on hemodynamic reserve to prevent CHS after CAS. Participants comprised 44 patients at high risk of CHS, whose ipsilateral cerebrovascular reactivity (CVR) was impaired on preoperative single photon emission computed tomography (SPECT). Patients were divided into a staged AP group (n=13) and a regular CAS group (n=31). In the staged AP group, stenting was performed 3 weeks after staged AP. In the regular CAS group, 16 cases (52%) showed HPP, and five (16%) presented with CHS after CAS, while no HPP or CHS occurred in the staged AP group (p=0.001). Changes in blood flow index (BFI) and time to peak (TTP) ratio during hypocapnia calculated from ICG-NIRS indicated a significant linear relationship with preprocedural CVR on SPECT (r=-0.710, 0.632, respectively; p<0.0001 each). BFI and TTP ratios during hypocapnia were significantly improved after staged AP (p<0.001 each). Furthermore, significant linear correlations were observed between BFI and TTP ratio during hypocapnia and postoperative asymmetry index AI (r=0.405, -0.475, respectively; p<0.01 each). Hypocapnia induced by hyperventilation under ICG-NIRS appears useful for detecting the effects of staged AP on hemodynamic reserve in patients at high risk of CHS.

Low relative diffusion weighted image signal intensity can predict good prognosis after endovascular thrombectomy in patients with acute ischemic stroke.

BACKGROUND: It is vital to identify a surrogate last-known-well time to perform proper endovascular thrombectomy in acute ischemic stroke; however, no established imaging biomarker can easily and quickly identify eligibility for endovascular thrombectomy and predict good clinical prognosis. OBJECTIVE: To investigate whether low relative diffusion-weighted imaging (DWI) signal intensity can be used as a predictor of good clinical outcome after endovascular thrombectomy in patients with acute ischemic stroke. METHODS: We retrospectively identified consecutive patients with acute ischemic stroke who were treated with endovascular thrombectomy within 24 hours of the last-known-well time and achieved successful recanalization (modified Thrombolysis in Cerebral Infarction score ≥2b). Relative DWI signal intensity was calculated as DWI signal intensity in the infarcted area divided by DWI signal intensity in the contralateral hemisphere. Good prognosis was defined as a modified Rankin Scale score of 0-2 at 90 days after stroke onset (good prognosis group). RESULTS: 49 patients were included in the analysis. Relative DWI signal intensity was significantly lower in the group with good prognosis than in the those with poor prognosis (median (IQR) 1.32 (1.27-1.44) vs 1.56 (1.43-1.66); p<0.01), and the critical cut-off value for predicting good prognosis was 1.449 (area under the curve 0.78). Multiple logistic regression analysis revealed association of good prognosis after endovascular thrombectomy with low relative DWI signal intensity (OR=6.84; 95% CI 1.13 to 41.3; p=0.04). CONCLUSIONS: Low relative DWI signal intensity was associated with good prognosis after endovascular thrombectomy. Its ability to predict good clinical outcome shows potential for determining patient suitability for endovascular thrombectomy.

Remarkable shrinkage of a thrombosed giant aneurysm by stent-assisted jam-packed coil embolization.

BACKGROUND: Large and giant aneurysms are known to involve intra-aneurysmal thrombosis and present a poor prognosis because of compression of the surrounding brain tissue with enlargement of the aneurysm. These aneurysms are difficult to cure by endovascular treatment due to involvement of the vasa vasorum in their pathology. We report this technical note to describe stent-assisted jam-packed coil embolization for the treatment of a giant thrombosed aneurysm. CASE DESCRIPTION: A 62-year-old man presented with right homonymous hemianopsia, and magnetic resonance imaging (MRI) showed a giant thrombosed aneurysm with poor wall contrast enhancement, which indicates little involvement of the vasa vasorum, at the terminal part of the left internal carotid artery. To block blood flow into the aneurysmal dome, stent-assisted "jam-packed" coil embolization was performed. For this, a braided stent was shortened to enhance metal coverage ratio and tight aneurysmal coil packing was performed using a hydrogel coil. Our technique resulted in complete obliteration of the aneurysm, and MRI performed 1 year later showed remarkable shrinkage of the aneurysm dome. CONCLUSION: Stent-assisted jam-packed coil embolization technique might be effective in shrinking the dome of giant thrombosed aneurysms with poor wall contrast enhancement.

Thoracolumbar intraosseous spinal epidural arteriovenous fistulas after vertebral compression fracture: A case report and literature review.

BACKGROUND: The pathophysiology of spinal epidural arteriovenous fistulas (SEAVFs) with perimedullary venous drainage remains to be elucidated. This report describes a case of intraosseous SEAVF in a patient with a history of a thoracolumbar vertebral fracture at the same level 10 years before presenting with progressive myelopathy secondary to retrograde venous reflux into the perimedullary vein. CASE DESCRIPTION: A 71-year-old man presenting with progressive paraparesis was diagnosed with a SEAVF involving a previous Th12 and L1 vertebral compression fracture on which feeders from multiple segmental arteries converged. The interesting feature of this case was that the fistula was located in the fractured vertebral body. The fistula was totally obliterated by transarterial embolization of the segmental arteries followed by symptom improvement. CONCLUSION: We presented a rare case of an intraosseous SEAVF secondary to a thoracolumbar compression fracture with perimedullary venous reflux causing progressive myelopathy. The fistula was located in the fractured vertebral body.

Lipid Core Burden Index Assessed by Near-Infrared Spectroscopy of Symptomatic Carotid Plaques: Association with Magnetic Resonance T1-Weighted Imaging.

INTRODUCTION: Vulnerable plaques are a strong predictor of cerebrovascular ischemic events, and high lipid core plaques (LCPs) are associated with an increased risk of embolic infarcts during carotid artery stenting (CAS). Recent developments in magnetic resonance (MR) plaque imaging have enabled noninvasive assessment of carotid plaque vulnerability, and the lipid component and intraplaque hemorrhage (IPH) are visible as high signal intensity areas on T1-weighted MR images. Recently, catheter-based near-infrared spectroscopy (NIRS) has been shown to accurately distinguish LCPs without IPH. This study aimed to determine whether the results of assessment of high LCPs by catheter-based NIRS correlate with the results of MR plaque imaging. METHODS: We recruited 82 consecutive symptomatic carotid artery stenosis patients who were treated with CAS under NIRS and MR plaque assessment. Maximum lipid core burden index (max-LCBI) at minimal luminal areas (MLA), defined as max-LCBIMLA, and max-LCBI for any 4-mm segment in a target lesion, defined as max-LCBIAREA, were assessed by NIRS. Correlations were investigated between max-LCBI and MR T1-weighted plaque signal intensity ratio (T1W-SIR) and MR time-of-flight signal intensity ratio (TOF-SIR) in the same regions as assessed by NIRS. RESULTS: Both T1W-SIRMLA and T1W-SIRAREA were significantly lower in the high LCP group (max-LCBI >504, p < 0.001 for both), while TOF-SIRMLA and TOF-SIRAREA were significantly higher in the high LCP group (p < 0.001 and p = 0.004, respectively). A significant linear correlation was present between max-LCBIMLA and both TIW-SIRMLA and TOF-SIRMLA (r = -0.610 and 0.452, respectively, p < 0.0001 for both). Furthermore, logistic regression analysis revealed that T1W-SIRMLA and TOF-SIRMLA were significantly associated with a high LCP assessed by NIRS (OR, 44.19 and 0.43; 95% CI: 6.55-298.19 and 0.19-0.96; p < 0.001 and = 0.039, respectively). CONCLUSIONS: A high LCP assessed by NIRS correlates with the signal intensity ratio of MR imaging in symptomatic patients with unstable carotid plaques.

Diagnostic impact of monitoring transcranial motor-evoked potentials to prevent ischemic complications during endovascular treatment for intracranial aneurysms.

The present study aimed to determine the incidence of intraprocedural motor-evoked potential (MEP) changes and to correlate them with intraprocedural ischemic complications and postprocedural neurological deficits in patients after endovascular intracranial aneurysm treatment. This study analyzed data from 164 consecutive patients who underwent endovascular coil embolization to treat intracranial aneurysms under transcranial MEP monitoring. We analyzed associations between significant changes in MEP defined as > 50% decrease in amplitude, and intraprocedural complications as well as postoperative neurological deficits. Factors associated with postprocedural neurological deficits were also assessed. The treated aneurysms were predominantly located in the anterior circulation (71%). Fourteen (9%) were located at perforators or branches that supplied the pyramidal tract. Intraprocedural complications developed in eight (5%) patients, and four of eight (50%) patients occurred postprocedural neurological deficits. Significant intraprocedural MEP changes occurred during seven of eight endovascular procedures associated with intraprocedural complications and salvage procedures were performed immediately. Among these changes, four transient MEP changes, recovered within 10 min, were not associated with postprocedural neurological deficits, whereas three permanent MEP changes were associated with postprocedural neurological deficits and mRS ≥ 1 at discharge. Aneurysms located at perforators/branches supplying the pyramidal tract, and permanent intraprocedural MEP changes were associated with postprocedural neurological deficits. We conclude that intraprocedural transcranial MEP monitoring can reliably identify ischemic changes and can initiate prompt salvage procedures during endovascular aneurysm treatment.

Lipid Core Plaque Distribution Using Near-infrared Spectroscopy Is Consistent with Pathological Evaluation in Carotid Artery Plaques.

Carotid artery stenting (CAS) is performed as a treatment for carotid artery stenosis. However, lipid-rich plaques cause embolic complications and sequelae. Near-infrared spectroscopy (NIRS) can identify lipid components by applying a near-infrared absorption pattern, and the distribution of lipid components can be evaluated as the maximum lipid core burden index (maxLCBI). Intravascular ultrasound (IVUS) equipped with NIRS has been clinically applied recently, and its diagnostic usefulness and validation have been reported for coronary arteries; however, its consistency with actual pathological diagnosis in carotid artery lesions has not been validated. In this study, we investigated the consistency between the maxLCBI values and histopathological diagnoses. Patients with cervical carotid artery stenosis who underwent carotid endarterectomy (CEA) were examined in this prospective study. Pathological diagnosis was determined after NIRS evaluation, which was performed on the extracted plaques ex vivo. The histological slices of decalcified and paraffin-embedded sections were stained by hematoxylin-eosin (HE) and Elastica van Gieson (EVG), and for low-density lipoprotein (LDL), C-reactive protein (CRP), CD68, and glycophorin A. The correlation between maxLCBI values and histological findings. Seventy lesions assessed by NIRS were pathologically analyzed. There was a positive linear correlation between maxLCBI values and pathological findings as determined by HE (angle), HE (area%), EVG, CRP, and CD68 staining (respectively, r = 0.624, p <0.001; r = 0.578, p <0.001; r = 0.534, p <0.001; r = 0.723, p <0.001; r = 0.653, p <0.001). In conclusion, the maxLCBI values assessed by NIRS showed a significant positive linear correlation with pathological evaluations in carotid lesions. The maxLCBI values in carotid arteries are consistent with pathological evaluations.

Elective carotid stenting after urgent best medical treatment suppresses recurrent stroke in patients with symptomatic carotid artery severe stenosis.

OBJECTIVE: Urgent carotid endarterectomy and carotid artery stenting (CAS) for symptomatic advanced carotid artery stenosis is controversial because carry risks of hemorrhagic and thromboembolic complications. As treatments for preventing recurrent stroke have recently advanced, this study evaluated whether elective CAS with urgent best medical therapy reduces recurrent stroke for symptomatic severe carotid artery stenosis. PATIENTS AND METHODS: A total of 131 consecutive patients who underwent CAS for severe stenosis of the carotid artery between 2013-2017 were divided into acute ischemic minor stroke (AIMS) and Asymptomatic groups. The AIMS group comprised 59 patients presenting with minor stroke who underwent elective CAS with oral dual antiplatelet therapy, statin therapy, and add-on oral omega-3 fatty acid ethyl esters from 4 weeks before CAS. The Asymptomatic group comprised 72 patients treated with best medical therapy for 4 weeks before CAS. RESULTS: No recurrent ischemic stroke was observed under urgent best medical treatment before elective CAS in the AIMS group. Although the frequency of vulnerable plaque and degree of stenosis were much higher in the AIMS group, no significant differences were seen in perioperative complications. Baseline serum eicosapentaenoic acid (EPA) levels and EPA/ arachidonic acid (AA) were significantly lower in the AIMS group (p = 0.04, 0.04, respectively) and serum EPA/AA was significantly increased a day before CAS and 3 months after CAS compared with baseline. CONCLUSION: Urgent best medical treatment reduces recurrent stroke and facilitates safe elective CAS in patients with symptomatic and severe carotid artery stenosis.

Central Retinal Artery Thromboembolism without Ophthalmic Artery Occlusion During Stent-Assisted Coil Embolization of Ophthalmic Artery Aneurysm.

BACKGROUND: Recent reports have described that endovascular treatment of coil embolization of opththalmic artery (OphA) aneurysms has a relative risk of visual disruption caused by thromboembolic infarction of the central retinal artery (CRA), especially the OphA when it originates within the body of the aneurysm. Patent microthrombus in the OphA might also cause retinal infarction that affects visual acuity. We describe stent-assisted coil embolization of an OphA aneurysm complicated with a severe visual disturbance, although normal flow was scrupulously maintained in the OphA during the procedure. The visual disturbance was recovered by early treatment. CASE DESCRIPTION: A 40-year-old woman who presented with an intracranial aneurysm arising from the right OphA underwent stent-assisted coil embolization under general anesthesia. Although the area around the origin of the OphA was intentionally avoided and anterograde flow in the OphA was monitored by repeated angiography during this procedure, sight in the right eye was lost immediately thereafter. The immediate application of ocular massage and intraarterial fibrinolysis improved vision in the right eye to essentially normal status after discharge. CONCLUSIONS: Despite good anterograde flow in the OphA during aneurysm embolization, the procedural risk of a visual disturbance due to thromboembolic complications of CRA occlusion cannot be avoided. Anterograde flow in the OphA and retinochoroidal blush should be monitored by repeated angiography during coil embolization to prevent vision loss. Should vision be lost, a rapid response including ocular massage and intraarterial fibrinolysis is required for recovery.

A case of filum terminale arterial venous fistula needed a long arterial access for trans-arterial shunt obliteration.

A 78-year-old man was referred to our institution with a predominantly progressive numbness of both legs, and bladder dysfunction with urinary retention. He was diagnosed as the symptomatic arteriovenous fistula of the filum terminale (AVFFT). A trans-arterial embolization (TAE) of the arteriovenous shunt was planned for his symptomatic AVFFT. The long distance between the origin of the radiculo meningeal artery (Th8) and the site of the fistula (S1) resulted in the first TAE having a feeder occlusion. The length of accessible feeder in the first TAE was the longest (about 40 cm) as the past reports of the endovascular therapy. However, complete shunt occlusion was accomplished at a second session two weeks after the initial TAE because a more accessible feeder was developed by the initial feeder occlusion.

Microvascular decompression for glossopharyngeal neuralgia using intraoperative neurophysiological monitoring: Technical case report.

BACKGROUND: Glossopharyngeal neuralgia (GN) is a rare functional disorder representing around 1% of cases of trigeminal neuralgia. Lancinating throat and ear pain while swallowing are the typical manifestations, and are initially treated using anticonvulsants such as carbamazepine. Medically refractory GN is treated surgically. Microvascular decompression (MVD) is reportedly effective against GN, superseding rhizotomy and tractotomy. METHODS: We encountered three patients with medically refractory GN who underwent MVD using intraoperative neurophysiological monitoring (IONM). The offending vessels were the posterior inferior cerebellar arteries, which were confirmed intraoperatively via a transcondylar fossa approach to be affecting the root exit zones of the glossopharyngeal and vagus nerves. As IONM, facial motor-evoked potentials (MEPs) and brainstem auditory-evoked potentials were monitored during microsurgery in all three patients. Pharyngeal and vagal MEPs were added for two patients to avoid postoperative dysphagia. RESULTS: GN disappeared immediately after surgery with complete preservation of hearing acuity and facial nerve function. Transient mild swallowing disturbance was observed in 1 patient without pharyngeal or vagal MEPs, whereas the remaining two patients with pharyngeal and vagal MEPs demonstrated no postoperative dysphagia. CONCLUSION: Although control of severe pain is expected in surgical intervention for GN, lower cranial nerves are easily damaged because of their fragility, even in MVD. IONM including pharyngeal and vagal MEPs appears very useful for avoiding postoperative sequelae during MVD for GN.

Cervical spinal epidural arteriovenous fistula with coexisting spinal anterior spinal artery aneurysm presenting as subarachnoid hemorrhage--case report.

Hemorrhagic presentation of spinal epidural arteriovenous fistulas (AVFs) is rare in patients with cervical spinal vascular lesions. The present report describes a patient with cervical spine epidural AVFs associated with anterior spinal artery aneurysm at the same vertebral level presenting with subarachnoid hemorrhage. A 54-year-old man presented with sudden onset of headache. Computed tomography of the head showed subarachnoid hemorrhage. Diagnostic angiography revealed an epidural AVF located at the C1-2 level that was fed mainly by the dorsal somatic branches of the segmental arteries from the radicular artery and anterior spinal artery. This AVF drained only into the epidural veins without perimedullary venous reflux. Further, there was a 4-mm anterior spinal artery aneurysm in the vicinity of the fistula that was thought to be the cause of the hemorrhage. Endovascular transarterial fistulas embolization from the right radicular artery was performed to eliminate the AVF and to reduce hemodynamic stress on the aneurysm. No new symptoms developed after the treatment and discharged without neurological deficits. The aneurysm was noted to be reduced in size after the treatment and totally disappeared by 1 year later, according to follow-up angiography. Anterior spinal artery aneurysm from a separate vascular distribution may coexist with spinal epidural AVFs. In the setting of spinal subarachnoid hemorrhage, comprehensive imaging is indicated to rule out such lesions.

Giant vertebral artery aneurysm in a child treated with endovascular parent artery occlusion and coil embolization.

BACKGROUND: Intracranial giant vertebral artery aneurysms are extremely rare in the pediatric population and are associated with significant morbidity and mortality. The present report describes a case of a pediatric patient with giant vertebral artery aneurysm who presented with intracranial mass effect. This patient was successfully treated with endovascular parent artery occlusion and coil embolization. CASE DESCRIPTION: A 7-year-old girl presented with tetraparesis, ataxia, dysphagia, and dysphonia. Cerebral angiography revealed intracranial giant aneurysm arising from the right vertebral artery. The patient underwent endovascular parent artery occlusion alone to facilitate aneurysmal thrombosis as an initial treatment. This was done to avoid a coil mass effect to the brainstem. However, incomplete thrombosis occurred in the vicinity of the vertebral artery union. Therefore, additional coil embolization for residual aneurysm was performed. Two additional coil embolization procedures were performed in response to recurrence. Mass effect and clinical symptoms gradually improved, and the patient had no associated morbidity or recurrence at 2 years after the last fourth coil embolization. CONCLUSION: Intracranial giant vertebral artery aneurysms are rare and challenging in pediatric patients. Staged endovascular strategy can be a safe and effective treatment option.