Intracranial Non-Sinus-Type Dural Arteriovenous Fistulas Could Be Curable by Transarterial Embolization or Transvenous Embolization with Liquid Embolic Material.

Objective: Recently, the occlusion rate of transarterial embolization (TAE) for intracranial non-sinus-type dural arteriovenous fistulas (NSDAVFs) has improved after ONYX was introduced. Additionally, when TAE for NSDAVF is unsuccessful, transvenous embolization (TVE) has become available as an alternative treatment. We investigated the factor for the favorable occlusion rate of endovascular treatment for NSDAVF at our institutions. Methods: Two hundred and twenty-seven patients with intracranial dural arteriovenous fistulas (DAVFs) were treated at our institutions between September 2014 and October 2022. The patients diagnosed with NSDAVF in all DAVFs who underwent endovascular treatment were included. The clinical characteristics, angiographical outcomes, and clinical outcomes of patients who underwent endovascular treatment were evaluated. Results: Thirty-eight patients had intracranial NSDAVF (tentorial: 23 cases, parasagittal-convexity: 7, anterior cranial fossa: 6, middle cranial fossa: 2). Our participants' mean age was 64.8 ± 11.3 years, and 31 (81.6%) of them were males. Patients' symptoms were as follows: asymptomatic (24), hemorrhage (10), tinnitus (3), and trigeminal neuralgia (1). TAE and TVE were performed on 35 and 3 patients, respectively. The rate of immediate angiographical occlusion was 84.2% (32/38). The follow-up angiographical occlusion rate in 6 months was 88.5% (31/35). Complications occurred in three cases. There was no morbidity or mortality after 30 days. Conclusion: TAE using the combination of the new microcatheter and microguidewire and TVE in the case of difficult or failed TAE for NSDAVF could achieve high success rates and safety.

A Case of Scalp Arteriovenous Malformation Treated by Transvenous Embolization Using Onyx.

Objective: We treated a case of scalp arteriovenous malformation (sAVM) by transvenous embolization using Onyx. Case Presentation: We describe the case of a 17-year-old woman with a pulsatile mass at the right temporal area. DSA identified sAVM with the venous pouch between the right occipital artery (OA) and the right two occipital veins (OVs), which was also fed by multiple branches of the right posterior auricular artery (PAA) and superficial temporal artery (STA). The shunts were completely occluded by the reverse pressure cooker technique (RPCT), which involves navigating the balloon catheters just distal to the shunt point in the OVs approaching from the right external jugular vein (EJV) and injecting Onyx to each feeder retrogradely with balloons inflated. Conclusion: This technique may be useful for treating sAVM with venous angioarchitecture enabling a transvenous approach.

In Vitro Measurement of Contact Pressure Applied to a Model Vessel Wall during Balloon Dilation by Using a Film-Type Sensor.

Objective: As an important evaluation index of vascular damage, the study aims to clarify the value of contact pressure applied to blood vessels and how it changes with respect to balloon pressure during balloon dilation. Methods: The contact pressure was evaluated through an in vitro measurement system using a model tube with almost the same elastic modulus as the blood vessel wall and our film-type pressure sensor. A poly (vinyl alcohol) hydrogel tube with almost the same elastic modulus was fabricated as the model vessel. The film-type sensor was inserted between the balloon catheter and the model vessel, and the balloon was dilated. Results: The contact pressure applied to the blood vessel was less than 10% of the balloon pressure, and the increase in contact pressure was less than 1% of the increase in balloon pressure (8 to 14 atm). Moreover, the contact pressure and its increase were larger in the model with a high elastic modulus. Conclusion: The contact pressure to expand the soft vessel model was not high, and the balloon pressure almost appeared to act on the expansion of the balloon itself. Our experiment using variable stiffness vessel models containing film-type sensors showed that the contact pressure acting on the vessel wall tended to increase as the wall became harder, even when the nominal diameter of the balloon was almost identical to the vessel. Our results can be clinically interpreted: when a vessel is stiff, the high-pressure inflation may rupture it even if its nominal diameter is identical to the diameter of the vessel.

Comprehensive Risk Analysis of the Wingspan Stent in Relation to Target Vessels.

Objective: To facilitate understanding for the safe use of the Wingspan stent, a comprehensive literature analysis was conducted, and incidence rates of 30-day stroke or death before and after the Stenting versus Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial were compared. We also investigated the associations between 30-day stroke or death rate and four lesion vessels, the internal carotid artery (ICA), middle cerebral artery (MCA), basilar artery (BA), and vertebral artery (VA). Methods: We searched MEDLINE, Embase, Web of Science, and Cochrane Library databases. The incidence rates of 30-day stroke or death in pre- and post-SAMMPRIS were compared using forest plots and funnel plots. Results: Thirty studies (15 before and 15 after the SAMMPRIS) were identified, comprising 2071 patients. Post-SAMMPRIS studies showed lower incidence rates of 30-day stroke or death compared to the pre-SAMMPRIS studies (8.5% vs. 5.6%, p = 0.014). The odds ratio of 30-day stroke or death of the post-SAMMPRIS group compared to that of the pre-SAMMPRIS group was 0.64 (95% confidence interval: 0.45-0.92, p = 0.014). The average 30-day stroke or death rates of overall, pre-, and post-SAMMPIS studies were 1.1%, 1.1%, and 1.1% for ICA; 6.2%, 8.8%, and 5.3% for MCA; 0.9%, 6.0%, and 2.7% for VA; and 13.5%, 15.1%, and 12.5% for BA, respectively. The post-SAMMPRIS study group showed significantly lower event rates for the treatment of MCA and VA than the pre-SAMMPRIS group did (p = 0.003 and p = 0.006, respectively). The incidence rates of ischemic and hemorrhagic stroke were 3.5% and 2.0%, respectively. Conclusion: This systematic surveillance study indicated that the modification of the indications for use based on the results of the SAMMPRIS trial for the Wingspan stent was effective in reducing 30-day stroke or death.

T-Stent or Half T-Stent-Assisted Embolization of Wide-Necked Aneurysms at the Internal Carotid-Posterior Communicating Artery Bifurcation.

Objective: We report the usefulness and pitfalls of coil embolization using the T or half T-stent technique for aneurysms located at internal carotid artery-posterior communicating artery (ICA-P-com) bifurcation in which the neck is wide and the P-com must be kept patent due to it being the fetal-type with a hypoplastic P1 segment. Case Presentations: Two cases were treated using the T-stent technique and two were treated using the half T-stent technique. The average age of the patients was 70.3 years and all were females. One aneurysm ruptured. The average size of aneurysms and neck was 12 mm and 8.5 mm, respectively, in the T-stent group, and 7.4 mm and 6.7 mm, respectively, in the half T-stent group. An S- or pigtail-shaped microcatheter (MC) was used to navigate into the P-com. Stent deployment was successful in all the cases. Retreatment was required in one case treated using the T-stent technique due to major recurrence. Conclusion: T or half T-stent-assisted coil embolization can be an alternative endovascular treatment method for wide-necked ICA-P-com aneurysms in which the P-com must be kept patent due to it being the fetal-type with a hypoplastic P1 segment.

[A Case of Erdheim-Chester Disease that was Difficult to Differentiate from Meningioma].

OBJECTIVE: Erdheim-Chester disease(ECD)is a rare type of non-Langerhans histiocytosis. We report a surgical case of ECD with multiple lesions at the falx cerebri, tentorium cerebelli, and in the suprasellar region, with a literature review. CASE REPORT: A 70-year-old woman presented with frequent falling and difficulty in standing. Her past medical history revealed ovarian cystectomy, transient thrombocytopenia, hypertension, left lower leg pain, and overactive bladder. Her head CT and MRI findings revealed well-defined mass lesions, suspected of meningioma, at the falx cerebri and tentorium cerebelli. Craniotomy and near total resection of the tumor at the falx cerebri was performed, leaving a hard portion of the tumor on the right falx. Intraoperative findings showed a solid and hard tumor, which was extremely difficult to decompress. Although the histopathological diagnosis was originally a metaplastic meningioma, considering her complaints of lower leg pain, we suspected ECD and performed a right tibial biopsy. The right tibial biopsy revealed ECD. Twenty-two months after the operation, the patient exhibited a marked enlargement of the tentorium lesion and a new lesion in the suprasellar region. Resection of the tentorial lesion was performed. The second intraoperative findings were similar to those of the first. The histopathological diagnosis of the tentorial lesion was ECD. After the surgeries, steroid therapy and radiation therapy were performed, but only with temporary improvement. CONCLUSION: ECD is a rare disease; therefore, accumulation of clinical data to establish its treatment is necessary.

[Bone drilling in microvascular decompression for trigeminal neuralgia: high morphological variety of the petrous bone].

Microvascular decompression is now a standard surgical technique for the treatment of trigeminal neuralgia. However, it is occasionally difficult to expose the trigeminal nerves because of the high anatomical variety of vascular or bony structures in the posterior fossa. We reported the case of a 59-year-old woman with trigeminal neuralgia whose site of neurovascular compression could not be observed in microvascular decompression. On approaching the trigeminal nerve, the suprameatal tubercle was so prominent that it prevented adequate visualization of the nerve tract. After drilling out the tubercle concealing the trigeminal nerve behind it, we exposed the nerve entirely and subsequently decompressed it from the superior cerebellar artery. Retrospectively, the suprameatal tubercle was found 3mm high above the posterior surface of the petrous bone. Then, we analyzed the height of suprameatal tubercles in 106 patients who underwent three-dimensional CT of the skull. Mean values of the suprameatal tubercles were 1.4-1.7mm in height, and 5.2% of them were higher than 3mm. The result suggested the high morphological variety of the petrous bone. We emphasize the importance of presurgical evaluation of the petrous bone in trigeminal neuralgia, because the neurovascular compression site may not be exposed sufficiently by the suprameatal tubercle in approximately 5% of the patients.

Endovascular recanalization of the completely occluded internal carotid artery using a flow reversal system at the subacute to chronic stage.

OBJECT: The efficacy and pitfalls of endovascular recanalization were evaluated in cases of internal carotid artery (ICA) occlusion in the subacute to chronic stage. METHODS: Fourteen cases (15 lesions) of symptomatic ICA occlusion with hemodynamic compromise or recurrent symptoms were treated at the subacute to chronic stage using an endovascular technique. The Parodi embolic protection system was used during the recanalization procedure to prevent embolic stroke by reversing the flow from the distal ICA to the common carotid artery. RESULTS: Recanalization of the occluded ICA was possible in 14 of 15 lesions. The occlusion points were 10 cervical ICAs and 4 petrous/cavernous ICAs in successfully recanalized cases. Ischemic symptoms disappeared completely after the treatment, and new ischemic symptoms did not appear related to the treated lesion. Single photon emission computed tomography findings demonstrated the improvement of hemodynamic compromise in all cases. One case showed right middle cerebral artery branch occlusion during the procedure, but this patient's neurological symptoms were stable due to preexisting hemiparesis. Endovascular recanalization was possible and effective in improving hemodynamic compromise. However, there are still several problems with this technique, such as hyperperfusion syndrome after recanalization, cerebral embolism during treatment, durability after treatment, and identification of the occlusion point before treatment. CONCLUSIONS: Endovascular recanalization using an embolic protection device can be considered as an alternative treatment for symptomatic ICA occlusion with hemodynamic compromise or refractoriness to antiplatelet therapy, even in the subacute to chronic stage of the illness.

Successful recanalization by in-stent percutaneous transluminal angioplasty with distal protection for acute carotid stent thrombosis.

A 71-year-old male presented with severe left cervical internal carotid artery stenosis manifesting as repeated transient ischemic attacks consisting of right hemiparesis and motor aphasia. Carotid artery stenting (CAS) under distal protection was performed to prevent further ischemic events. This procedure was uneventful. However, the patient exhibited progressive right hemiparesis and motor aphasia 3 days after CAS. Emergent angiography revealed carotid artery occlusion due to in-stent thrombosis. In-stent percutaneous transluminal angioplasty (PTA) was performed under distal protection. The carotid artery was recanalized with small residual thrombus. The neurological deficits almost completely disappeared after PTA. Follow-up angiography 9 months after stenting showed restenosis but no in-stent thrombosis. Carotid thrombosis after CAS can be resolved by in-stent PTA under distal protection and subsequent treatment with antithrombotic agents.

Endovascular treatment for pseudo-occlusion of the internal carotid artery.

OBJECTIVE: The surgical benefit to pseudo-occlusion of the internal carotid artery (ICA) is controversial. Because the benefit of carotid endarterectomy for pseudo-occlusion of the ICA remains uncertain, we examined the use of carotid stenting as a possible alternative treatment for this condition. METHODS: Twenty cases of carotid pseudo-occlusion (17 symptomatic, three asymptomatic) were treated with carotid artery stenting. Nineteen patients were treated with various embolic protection techniques. Our clinical results, including angiographic follow-up data, perioperative complications, and data on the effectiveness of the embolic protection methods were studied for ICA pseudo-occlusion. RESULTS: All pseudo-occlusions were successfully dilated, and the stenotic ratio was reduced from 95 to 6.7% on average. No neurological deterioration was encountered in any of the cases, although one patient died of cardiac event 1 day after treatment. None of the patients experienced stroke during the mean 24.8 month follow-up period, although one patient died from myocardial infarction. Among the 17 cases in which follow-up angiography was performed at 6 months after stenting, only one patient demonstrated restenosis. This patient was successfully treated with repeated percutaneous transluminal angioplasty. The rate of restenosis in our series was 5.9%, and the morbidity/mortality rate within 30 days was 5%. CONCLUSION: The clinical results of carotid stenting for ICA pseudo-occlusion under embolic protection were fairly good from the viewpoints of periprocedural neurological morbidity, angiographic follow-up results, and stroke prevention. Carotid stenting can be considered an alternative to carotid endarterectomy in patients with ICA pseudo-occlusion.

Hemorrhagic complications after endovascular therapy for atherosclerotic intracranial arterial stenoses.

OBJECTIVE: Hemorrhagic complications were analyzed in 106 procedures of 99 patients treated with percutaneous transluminal angioplasty (PTA) or stenting for intracranial arterial stenoses. METHODS: Ninety-nine patients with intracranial arterial stenosis were treated with PTA or stenting 106 times from January 1995 to December 2003. Fifty-seven patients had intracranial internal carotid artery stenosis, 23 had middle cerebral artery stenosis, and 19 had vertebrobasilar stenosis. Evaluation of hemodynamic compromise via single-photon emission computed tomography was performed 50 times for 50 patients before the treatment. RESULTS: Four hemorrhagic complications occurred in 106 procedures. Two of these cases involved intracerebral hemorrhage after PTA or stenting in the treated vascular territory 30 minutes and 16 hours after the treatment, respectively. One case showed subarachnoid hemorrhage, which appeared 6 hours after treatment. Hemodynamic compromise was found on single-photon emission computed tomography in these three cases. The last case with a hemorrhagic complication was a hemorrhagic infarction after recanalization of stent thrombosis, which appeared 3 days after stenting. Hyperperfusion syndrome was strongly suggested as the cause of hemorrhage in the two cases associated with intracerebral hemorrhage. CONCLUSION: The rate of hemorrhagic complication directly related to the procedure of PTA or stenting was 3%, and hyperperfusion syndrome was suggested as the cause of hemorrhage in two cases (2%), from the perspective of clinical characteristics and single-photon emission computed tomographic findings.

Carotid artery stenting for stenosis with intraluminal thrombus.

Since intraluminal thrombus in the context of carotid artery stenosis is rarely encountered, treatment for this condition remains controversial. The present paper describes six cases of carotid artery stenosis with thrombus and discusses the efficacy and complications of carotid artery stenting (CAS). From April 2002 to May 2004, six patients with carotid artery stenosis and intraluminal thrombus receiving medical therapy underwent CAS at our institution. CAS was performed with distal protection alone (method 1) in three patients, and three other patients underwent CAS with reversed-flow system and distal protection (method 2). Two of six patients experienced worsening neurologic symptoms despite medical therapy. All six patients were successfully treated with CAS and showed satisfactory patency of the artery. Embolic lesions were detected on diffusion-weighted MRI after the procedure in all patients treated with method 1 but not in patients treated with method 2. Complications included stent thrombosis (n=1) and in-stent thrombus (n=1). All six patients achieved a modified Rankin Scale 1 or 2 classification at 30 days after stenting. In conclusion, CAS was feasible for stenosis even with intraluminal thrombus. Use of method 2 for this condition may reduce the incidence of thromboembolic events although our series was small in number.

Use of an embolic protection system during endovascular recanalization of a totally occluded cervical internal carotid artery at the chronic stage. Case report.

A symptomatic internal carotid artery (ICA) occlusion with hemodynamic compromise was treated at its chronic stage by using an endovascular technique. An embolic protection system was used during the recanalization procedure to prevent stroke by reversing the flow from the distal ICA to the common carotid artery. The totally occluded ICA was completely recanalized through percutaneous transluminal angioplasty and stent placement. The patient's symptom (transient ischemic attack) disappeared completely after treatment with no new neurological deficit. Single-photon emission computerized tomography findings confirmed improvement of the hemodynamic compromise, and no new high-intensity spots appeared on diffusion-weighted magnetic resonance imaging after treatment. This case shows that endovascular recanalization by using an embolic protection device can be considered as an alternative treatment for symptomatic ICA occlusion with hemodynamic compromise and refractoriness to antiplatelet therapy, even in the chronic stage of the illness.

Diffusion-weighted imaging abnormalities after percutaneous transluminal angioplasty and stenting for intracranial atherosclerotic disease.

BACKGROUND AND PURPOSE: The literature contains relatively few reports of distal embolism associated with intervention for intracranial atherosclerotic disease. Our purpose was to evaluate the frequency of thromboembolic events after percutaneous transluminal angioplasty (PTA) or stent placement in this setting by using diffusion-weighted (DW) imaging. METHODS: Between October 1999 and January 2004, 16 consecutive patients with symptomatic intracranial arterial stenosis greater than 60% were treated with PTA or stent placement without a protection system. Whole-brain DW imaging was performed before and after intervention. DW imaging findings were retrospectively analyzed and divided into three groups according to new hyperintensities: type A was none; type B, a single lesion; and type C, multiple lesions. RESULTS: Nine type A, five type B, and three type C lesions were detected after the interventions. All hyperintense lesions were less than 5 mm in diameter. All type C lesions occurred in the context of internal carotid artery stenosis treated with stent placement. DW imaging abnormalities occurred most frequently when PTA followed by stent placement was performed for long internal carotid artery stenoses. No new neurologic deficits occurred in any patient. CONCLUSION: In this series, PTA or stent placement or both for intracranial atherosclerotic lesions was safe. New DW imaging abnormalities were less frequent in patients who underwent PTA alone or primary stent placement than in those receiving PTA followed by stent placement.

Endovascular therapy for acute thrombotic occlusion of the intracranial artery.

The goal of this study was to evaluate the efficacy of endovascular therapy for acute thrombotic occlusion. Six patients with acute thrombotic occlusion in the middle cerebral or basilar arteries underwent treatment with intra-arterial thrombolysis, followed by assessment of residual stenosis. If residual stenosis was greater than 70%, percutaneous transluminal angioplasty (PTA) was performed in the same session; otherwise, patients were anticoagulated, and PTA was performed several days later. Successful recanalization was achieved in five of six patients. One patient died of massive infarction, because of the failure of recanalization of the M1 segment. At discharge, modified Rankin scale distribution of the patients was: grade 0, one patient; grade 1, one patient; grade 2, two patients; grade 3, one patient; grade 6, one patient. Retreatment was required via PTA or stenting in two patients in which type C stenosis was present. In conclusion, endovascular therapy for acute thrombotic occlusion of an intracranial artery appears to be effective compared to conservative therapy. However, further refinement of the technique is required to prevent various complications, including vessel perforation, dissection, perforating artery occlusion and restenosis.

Results of endovascular treatment of internal carotid artery stenoses with a newly developed balloon protection catheter.

OBJECTIVE: A new balloon protection catheter to prevent distal emboli during internal carotid artery percutaneous transluminal angioplasty and stenting was developed, and its efficacy was evaluated in both an experimental model and clinical cases. METHODS: The balloon protection catheter was navigated over a steerable 0.014-inch guidewire to negotiate tight stenoses and sharp bends, which would cause difficulties for the passage of a flow-directed balloon catheter. Percutaneous transluminal angioplasty and stenting were performed for 85 consecutive patients with 87 stenotic lesions of the cervical internal carotid artery, with two different methods using this protection system. Distal protection was provided only after dilation for the initial 38 lesions (Group I), but the latter 49 lesions were treated in both the pre- and postdilation periods (Group II). The effects of using the balloon protection catheter with the embolic debris clearance technique were evaluated with pre- and postoperative magnetic resonance imaging for each group. RESULTS: The balloon protection catheter was introduced beyond the stenosis in all cases. In Group I, one symptomatic embolic stroke was caused by distal embolization resulting from atheromatous plaque, and high-intensity areas appeared on diffusion-weighted magnetic resonance imaging scans in 47% of cases. In contrast, in Group II, there were no strokes related to the procedure, although one patient with multiple risk factors died suddenly on the second day after stenting. Diffusion-weighted imaging scans demonstrated small, high-intensity areas in 19% of cases in Group II. The overall morbidity/mortality rate in our series was 2.3%. CONCLUSION: Our new balloon protection catheter was reliably navigated across internal carotid artery stenoses and reduced distal embolism in clinical cases.

Endovascular therapy for stenosis of the petrous or cavernous portion of the internal carotid artery: percutaneous transluminal angioplasty compared with stent placement.

OBJECT: The effects of percutaneous transluminal angioplasty (PTA) and stent placement for stenosis of the petrous or cavernous portion of the internal carotid artery (ICA) were compared. METHODS: Twenty-four patients with symptomatic, greater than 60% stenosis of the petrous or cavernous portion of the ICA were treated using PTA or stent placement; 15 were treated with PTA and nine with stent insertion. Initial and follow-up results (> 3 months posttreatment) were compared in each group. Stenotic portions of the ICA were successfully opened in 13 of 15 patients in the PTA group, and in all nine patients in the stent-treated group. In one case in the PTA group stent delivery was attempted; however, the device could not pass through the vessel's tortuous curve, and PTA alone was performed in this case. Postoperatively, the mean stenotic ratio decreased from 72.1 to 29.6% in the PTA group, and from 75.6 to 2.2% in the stent-treated group. In four patients in the PTA group, stenoses greater than 50% were demonstrated on follow-up angiography performed at 3 to 6 months after PTA. In the stent-treated group, no restenosis was encountered, although in one case acute occlusion of the stent occurred; the device was recanalized with PTA and infusion of tissue plasminogen activator. This case was the only one of the 24 in which any neurological deficits related to the endovascular procedure occurred. Stent placement brought a greater gain in diameter than did PTA at the initial and late follow-up period; this gain was statistically significant. CONCLUSIONS: Stent placement is more effective than PTA for stenosis of the petrous or cavernous portion of the ICA from the viewpoint of initial and late gain in diameter.

Relationships between event-related potentials and neuropsychological tests in neurologically healthy adults.

The aim of this study was to investigate the relationship between conventional neuropsychological tests and an event-related potential (P300). Subjects were 118 neurologically normal healthy adults 18-74 years old with no history of neurological, neurosurgical, or psychiatric disorders. We administered a neuropsychological test battery and recorded auditory P300 in all subjects. A significant correlation was seen between P300 latency and age, but not between amplitude and age. While significant negative correlations were apparent between some neuropsychological tests and age and P300 latency, stepwise regression analysis to assess the significance of each factor determined that age alone correlated with P300 latency. We therefore concluded that P300 measurements cannot be replaced by neuropsychological tests; rather, brain function should be evaluated by both methods.