Partially thrombosed giant basilar tip aneurysm that remarkably decreased in size after stent-assisted coiling associated with the disappearance of neovascularization.

Endovascular treatment for partially thrombosed giant basilar tip aneurysms has not been established because of its low cure rate and numerous associated comorbidities. Although some authors reported the growth mechanism of partially thrombosed aneurysm, there is no report for the process of its shrinkage after treatment. We describe a case of a partially thrombosed giant basilar tip aneurysm presenting with disturbance of consciousness because of a mass effect and brain edema. The patient underwent stent-assisted coiling using a low-profile visualized intraluminal support stent (Terumo). Although pre-operative magnetic resonance imaging (MRI) and angiography revealed prominent neovascularization of the inner aneurysmal layer, this vessel was absent on follow-up angiography 1 month after treatment. Repeat angiography demonstrated the gradual recanalization of the aneurysm. However, repeat MRI examinations showed remarkable shrinkage of the thrombosed aneurysm, and the complete disappearance of the thrombosed component was noted 6 months after treatment. The disappearance of neovascularization 1 month after the treatment may have contributed to the shrinkage of the thrombosed aneurysm. Stent-assisted coiling combined with alteration caused a hemodynamic change in this aneurysm, and the flow-diverting effect might have controlled this partially thrombosed giant aneurysm.

[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.

[Transvenous Embolization by Direct Puncture of the Superior Sagittal Sinus Using Indocyanine Green(ICG)Videoangiography for Treatment of Dural Arteriovenous Fistula of the Transverse-Sigmoid Sinus:A Case Report].

We report a case of dural arteriovenous fistula at the left transverse sinus and sigmoid sinus(TS-dAVF), which was treated with transvenous embolization(TVE)by direct puncture of the superior sagittal sinus(SSS)under indocyanine green(ICG)fluoroscopic guidance. A 71-year-old woman presented with pulsatile tinnitus and progressive dementia. A left TS-dAVF with retrograde SSS and cortical venous reflux(Cognard type IIb)was demonstrated on cerebral angiography. The left internal jugular vein and distal portion of the right transverse sinus were occluded. We considered that TVE via the femoral vein would be difficult for complete cure. We performed trepanation of the frontal portion of the SSS. The SSS was directly punctured with an 18-G needle under ICG fluoroscopic guidance. We inserted a 4-Fr sheath into the SSS. A microcatheter was navigated into the affected sinus. Coils were placed through the microcatheter. The dAVF was completely diminished. No complications occurred. The patient's pulsatile tinnitus disappeared and dementia improved. Transvenous approach with direct puncture of the SSS under ICG fluoroscopic guidance was a useful approach for the treatment of dAVF when other approaches were difficult.

In vitro experiments of vessel wall apposition between the Enterprise and Enterprise 2 stents for treatment of cerebral aneurysms.

BACKGROUND: A closed-cell stent called Enterprise has been used for stent-assisted coil embolization of cerebral aneurysms. The Enterprise stent tends to cause kinks and vessel wall malposition in curved vessels and may cause thromboembolic complications. We evaluated vessel wall apposition of a new closed-cell stent, Enterprise 2, compared with a previous Enterprise stent, using curved vascular silicone models. METHODS: The Enterprise or Enterprise 2 stent was deployed in curved vascular models with various radii of approximately 5 to 10 mm. Stent deployment was performed 25 times in each stent. A push-pull technique was used to minimize incomplete wall apposition. To evaluate conformity of stents, gaps between a stent and a vessel wall were measured. RESULTS: The gap ratio (gap / a wall diameter) was 15 % ± 17 % (mean ± standard deviation) and 41 % ± 15 % with the Enterprise 2 stent and the Enterprise stent, respectively. Taking gap ratios and radii of vessel curvature into consideration, the Enterprise 2 stent had significantly better wall apposition than the Enterprise stent (p = 0.005). In the same radius of vessel curvature, the Enterprise 2 stent had approximately half of the gap compared with the Enterprise stent. There were no significant differences in vessel straightening effects between the two stents. CONCLUSIONS: The Enterprise 2 stent has better wall apposition in curved vessels than the Enterprise stent. The gap between a vessel wall and the Enterprise 2 stent is approximately half that of the Enterprise stent. However, gaps and kinks are still present in curved vessels with a small radius. Caution should be taken for kinks and malposition in acutely curved vessels, such as the siphon of the internal carotid artery.

[A Ruptured Vertebral Artery Dissecting Aneurysm Involving the Anterior Spinal Artery:A Case Report].

A 50-year-old woman presented with a subarachnoid hemorrhage caused by a ruptured vertebral artery dissecting aneurysm(VADA)involving the anterior spinal artery(ASA). The ASA branched at the proximal component of the dissecting aneurysm. The rupture point was presumed to be the distal region of the dissecting aneurysm. We performed coil embolization of the distal part only in order to prevent rebleeding and preserve the ASA. The patient showed no neurological deficits. Six months after the procedure, an angiogram demonstrated occlusion of a distal portion of the right vertebral artery. However, the ASA was still patent. No rebleeding occurred, and the patient has remained neurologically symptom-free for 3 years from the treatment. ASA-involved VADAs are extremely rare. Treatment strategy is difficult because there are no options for bypass surgery and occlusion of the ASA may lead to quadriplegia unless there is collateral flow to the ASA. Although the outcome of the patient was good with partial coil embolization in this case, the treatment strategy should be carefully considered for ASA-involved VADAs.

Flow visualization of recurrent aneurysms after coil embolization by 3D phase-contrast MRI.

BACKGROUND: Flow patterns in cerebral aneurysms are clinically important. Information on inflow patterns into aneurysms is especially helpful in preventing a recurrence after coil embolization. Computational fluid dynamics (CFD) simulations of patient-specific cerebral aneurysms are feasible and provide information on flow patterns. However, flow visualization by CFD simulations is challenging for recurrent aneurysms after coil embolization because coils make it difficult to obtain precise geometry of the recurrent aneurysms. In this study, we assessed the feasibility of flow visualization of recurrent aneurysms using 3D phase-contrast magnetic resonance imaging (PC-MRI). METHOD: Time-of-flight magnetic resonance angiography and 3D PC-MRI were performed in eight cases of recurrent aneurysms after coil embolization. We attempted to visualize flow inside the aneurysms using data of 3D PC-MRI and evaluated the visualization. Additionally, CFD simulations were performed in a single case. RESULTS: Inflow into aneurysms was visualized in all eight cases (100%). Flow patterns inside aneurysms were visualized in six cases (75%), and these were associated with a large size of recurrent aneurysms (mean size, 10.3 mm for visualized cases vs. 4.8 mm for unvisualized cases; p = 0.046, Mann-Whitney test). Flow patterns were similar between PC-MRI and CFD simulations. PC-MRI was faster and easier for observing inflow patterns than CFD simulations. CONCLUSIONS: This is the first study to demonstrate that flow visualization of recurrent aneurysms by 3D PC-MRI is feasible. This technique may be more practical and easier than CFD simulations, and may provide clinically helpful information.

Feasibility of insertion of a microcatheter through a Y-stent in coil embolization of cerebral aneurysms and its detailed geometry by micro-computed tomography.

BACKGROUND: In Y-stent-assisted coil embolization for cerebral aneurysms, open or closed cell stents are used. Different microcatheters for coil insertion are available. We investigated which microcatheter could be navigated into an aneurysm through a Y-stent with different stents. METHODS: Double Neuroform open-cell stents or double Enterprise closed-cell stents were deployed in Y-configuration in a silicon model of a bifurcation aneurysm. Two endovascular neurosurgeons independently tried to navigate an SL-10 microcatheter for 0.010" coils or a PX Slim microcatheter for 0.020" Penumbra coils into the aneurysm through the Y-stent. In addition, we measured lengths of stent pores of the Y-stents with double Enterprise stents deployed in the model by micro-computed tomography. RESULTS: It was feasible to navigate an SL-10 microcatheter into the aneurysm through the Y-stent with Enterprise or Neuroform stents. Navigation of a PX Slim microcatheter was feasible in the Y-stents only with Neuroform stents. In the Y-stent with double Enterprise stents, the lengths of the second stent pores were significantly smaller than those of the first stent (0.41 ± 0.18 mm vs 0.69 ± 0.20 mm; P = 0.008). The SL-10 microcatheter was smaller than approximately 80% of the stent pores of the first stent and 30% of those of the second stent. The PX Slim microcatheter was smaller than 20% of the stent pores of the first stent and 0% of those of the second stent. CONCLUSIONS: It was feasible to insert an SL-10 microcatheter into the aneurysm through Y-stents with Enterprise or Neuroform stents. Navigation of a PX Slim microcatheter for 0.020" Penumbra coils was feasible in Y-stents with Neuroform stents, but not with double Enterprise stents. The measurements of stent pores by micro-computed tomography supported this feasibility study. These results may be helpful to select appropriate stents and microcatheters in Y-stent-assisted coil embolization, especially in case of retreatments.

Non-enhanced magnetic resonance angiography can evaluate restenosis after carotid artery stenting with the Carotid Wallstent.

BACKGROUND: Carotid artery stenting (CAS) requires follow-up imaging to assess in-stent restenosis (ISR). This study aimed to determine whether non-enhanced magnetic resonance angiography (NE-MRA) is useful for evaluating ISR. METHOD: Between 2009 and 2013, we performed 118 consecutive CAS procedures using the Precise stent (n = 78) and the Carotid Wallstent (n = 40). We reviewed 1.5 T NE-MRA and examined visualization of the stent lumen and the degree of ISR if present. Other imaging modalities were used as references. RESULTS: NE-MRA performed just after CAS was not able to visualize the stent lumen in all patients because of metal artifacts. In the Carotid Wallstent group, follow-up NE-MRA was available in 22 patients. The stent lumen was visible more than three months after CAS in all patients. Among them, >40 % ISR was observed by other modalities in eight lesions. The degree of restenosis measured by NE-MRA (y%) had a linear relationship with that measured by conventional angiography (x%) (y = 0.97x-0.4, r = 0.79, P = 0.021). In one case among 17 without ISR (6 %), NE-MRA showed false ISR. In the Precise stent group, NE-MRA did not visualize the stent lumen in the follow-up period. CONCLUSIONS: NE-MRA can visualize the stent lumen in the Carotid Wallstent more than three months after CAS, but not in the Precise stent at follow-up. This delayed visualization might depend on endothelialization of the stent lumen. The degree of ISR measured by NE-MRA is comparable to that by conventional angiography. NE-MRA can evaluate ISR after CAS with the Carotid Wallstent (100 % sensitivity and 94 % specificity).

Prospective registry of carotid artery stenting in Japan--investigation on device and antiplatelet for carotid artery stenting.

BACKGROUND: Carotid artery stenting (CAS) is minimally invasive but may cause perioperative cerebral infarction associated with distal embolization. We conducted a multicenter prospective observational study on the onset of vascular events after CAS to find out the efficacy and safety of CAS in Japan and to investigate the effects of antiplatelet drugs administered before and after CAS on efficacy and safety of CAS. METHODS: A total of 949 patients with cervical carotid artery stenosis were enrolled at 43 institutions in Japan; 934 who had undergone CAS with antiplatelet drugs and followed for 1 year were analyzed. Primary end point was the incidence of the first event of death, ischemic stroke, hemorrhagic stroke, transient ischemic attack, myocardial infarction, or serious hemorrhage within 1 year after enrollment. Comparison of the incidences of events according to antiplatelet drugs was also conducted. RESULTS: The primary end point was observed in 69 patients (7.4%) within 30 days of enrollment and in 40 patients (4.3%) between 31 days and 1 year after enrollment. The incidence of the first event for aspirin+cilostazol was significantly lower than that for aspirin+clopidogrel (P=.01), aspirin+clopidogrel+cilostazol (P=.01), and antiplatelet monotherapy (P<.01). Patient age (P=.01), presence of ischemic cerebrovascular disease (P=.02), presence of antidiabetic drugs (P<.01), femoral artery puncture (P=.02), guiding catheter used (P=.02), and Angioguard XP used (P=.01) were also correlated with the primary end point. CONCLUSION: Incidences of the primary end point within 30 days and 1 year of enrollment were comparable with previous reports, suggesting that CAS is a useful alternative for carotid endarterectomy in carotid stenosis patients with high risk for carotid endarterectomy. Further randomized controlled studies are needed to determine whether differences in mechanism of action of antiplatelet drugs might have contributed to the results of the present study.

[Distal posterior cerebral artery aneurysm at the P4 segment: a case report].

Posterior cerebral artery (PCA) aneurysms are rare, especially those at the P4 segment. We report such a case involving a 77-year-old man who suffered from a sudden-onset headache. Computed tomography showed intracerebral hemorrhage in the left occipital lobe, intraventricular hemorrhage, and subarachnoid hemorrhage at the left occipital sulcus. Magnetic resonance angiography failed to reveal any aneurysms or abnormal vessels. Because the patient had renal dysfunction, we refrained from conventional angiography. Five days after the initial onset, rebleeding occurred, and conventional angiography revealed a small(2-mm)PCA aneurysm in the left P4 segment. We performed endovascular treatment and occluded the parent artery with a liquid embolic material, n-butyl-2-cyanoacrylate. The etiology of the aneurysm was not determined. The patient did not suffer from any apparent visual field deficits and was transferred to a rehabilitation hospital. Reviewing previous reports of distal PCA aneurysms indicated that PCA aneurysms in the P4 segment have two characteristics that distinguish them from other PCA aneurysms:P4 segment aneurysms are relatively small and the resulting hematoma distribution tends to be manifest as a combination of intracerebral hemorrhage, intraventricular hemorrhage, and subarachnoid hemorrhage at the occipital sulcus. With respect to these characteristics, our case was a typical P4 segment aneurysm. In conclusion, although P4 segment aneurysms are rare, if the characteristic hematoma distribution is observed, conventional angiography should be performed to confirm a possible P4 segment aneurysm. Parent artery occlusion with a liquid embolic material may be a treatment option for selected cases.

Pioneering artificial intelligence-based real time assistance for intracranial liquid embolization in humans: an initial experience.

BACKGROUND: Liquid embolization in neuroendovascular procedures carries the risk of embolizing an inappropriate vessel. Operators must pay close attention to multiple vessels during the procedure to avoid ischemic complications. We report our experience with real time artificial intelligence (AI) assisted liquid embolization and evaluate its performance. METHODS: An AI-based system (Neuro-Vascular Assist, iMed technologies, Tokyo, Japan) was used in eight endovascular liquid embolization procedures in two institutions. The software automatically detects liquid embolic agent on biplane fluoroscopy images in real time and notifies operators when the agent reaches a predefined area. Safety, efficacy, and accuracy of the notifications were evaluated using recorded videos. RESULTS: Onyx or n-butyl-2-cyanoacrylate (NBCA) was used in the treatment of arteriovenous malformation, dural arteriovenous fistula, meningioma, and chronic subdural hematoma. The mean number of true positive and false negative notifications per case was 31.8 and 2.8, respectively. No false positive notifications occurred. The precision and recall of the notifications were 100% and 92.0%, respectively. In 28.3% of the true positive notifications, the operator immediately paused agent injection after receiving the notification, which demonstrates the potential effectiveness of the AI-based system. No adverse events were associated with the notifications. CONCLUSIONS: To the best of our knowledge, this is the first report of real time AI assistance with liquid embolization procedures in humans. The system demonstrated high notification accuracy, safety, and potential clinical usefulness in liquid embolization procedures. Further research is warranted to validate its impact on clinical outcomes. AI-based real time surgical support has the potential to advance neuroendovascular treatment.

Changes in wall shear stress magnitude after aneurysm rupture.

Computational fluid dynamics (CFD) studies on cerebral aneurysms have attempted to identify surrogate hemodynamic parameters to predict rupture risk. We present a case of bilateral mirror image aneurysms, one of which ruptured soon after imaging. Wall shear stress values of the ruptured aneurysm changed by 20-30% after rupture because of change in the aneurysm shape. Findings from our case suggest that CFD studies comparing unruptured and ruptured aneurysms may not yield valid estimation on aneurysm rupture risk because of changes in aneurysm shape after rupture. Changes in aneurysm shape after rupture should be considered in CFD research.

Triple antiplatelet therapy with addition of cilostazol to aspirin and clopidogrel for Y-stent-assisted coil embolization of cerebral aneurysms.

BACKGROUND: Dual antiplatelet therapy for stent-assisted coiling of cerebral aneurysms is essential to prevent thromboembolic complications. There is concern that Y-stent-assisted coiling may increase thromboembolic complications compared with coiling with a single stent. Several reports have demonstrated that cilostazol may improve clopidogrel responsiveness. We investigated whether triple antiplatelet therapy with addition of cilostazol to aspirin plus clopidogrel for Y-stents can prevent thromboembolic events. METHODS: Between July 2010 and October 2012, we treated 40 consecutive aneurysms with coil embolization using Enterprise stents. At the peri-procedural period, dual antiplatelet agents (100 mg aspirin and 75 mg clopidogrel) were used for the single stent group (n = 36), and triple antiplatelet agents (addition of 200 mg cilostazol) were used for the Y-stent group (n = 4). We evaluated post-operative diffusion-weighted imaging (DWI) and any complications. We assessed the following for statistical analysis: age, sex, aneurysm location, shape, and size, neck size, size of parent vessels, and stent length. RESULTS: We found two neurological peri-procedural complications: one transient ischemic attack and one infarction. Both complications belonged to the Y-stent group, which was a significant factor of thromboembolic events (P = 0.008). There were no other significant factors related to neurological complications or positive DWI. For subgroup analysis of the single stent group, stent length was significantly longer in positive DWI than negative DWI (P = 0.04). In the follow-up period of 20 ± 8.6 months, there were no symptomatic late complications in any patients. CONCLUSIONS: Although the number of patients in the Y-stent group is small, this group had a significantly higher risk of thromboembolic complications. While our protocol of a routine dose of dual antiplatelet therapy may be sufficient for single stent therapy, our protocol of a routine dose of triple antiplatelet therapy for Y-stents may not prevent thromboembolic events. This suggests that evaluation of platelet function may be essential, especially for Y-stents.

The clinical results of transcervical carotid artery stenting and frequency chosen as the approach route of carotid artery stenting in 1,067 consecutive cases.

BACKGROUND: Carotid artery stenting (CAS) is generally performed via a transfemoral approach. A transbrachial approach is usually chosen as an alternative when CAS via a transfemoral approach is difficult. At our institutions, a transcervical approach is chosen when the previous two approach routes are not available. We reviewed CAS cases treated via the transcervical route in our 1,067 CAS series to investigate the safety, feasibility, and frequency of this procedure as an approach route of CAS. METHODS: We performed 1,067 CAS procedures in 1,067 consecutive cases between December 2002 and June 2011. Initially, a transfemoral route was chosen, and secondarily a transbrachial route, the last choice was a transcervical route. A transbrachial approach was chosen in 96 (9.0%) cases and a transcervical approach in ten (0.9%). We reviewed the characteristics and outcomes of CAS performed via a transcervical approach. RESULTS: CAS was successfully performed on all ten transcervical-approach patients. Eight procedures were performed under local anesthesia and two under general anesthesia. Perioperative morbidity and mortality were both 0%. The modified Rankin scale (mRS) showed no deterioration at 3 months except for one case whose mRS became five because of an embolic stroke after aortic valve replacement. CONCLUSIONS: CAS via a transcervical approach was safe and feasible, and its frequency chosen as an approach route was 0.9%. This procedure can be an alternative to transfemoral or transbrachial approaches when CAS via either of these approaches is too difficult.

Stroke outcomes of Japanese patients with major cerebral artery occlusion in the post-alteplase, pre-MERCI era.

This study examined outcomes of patients with acute ischemic stroke (AIS) with major cerebral artery occlusion after the approval of intravenous recombinant tissue-type plasminogen activator (IV rt-PA) but before approval of the MERCI retriever. We retrospectively enrolled 1170 consecutive patients with AIS and major cerebral artery occlusion (496 women; mean age, 73.9 ± 12.3 years) who were admitted within 24 hours after the onset of symptoms to 12 Japanese stroke centers between October 2005 and June 2009. Cardioembolism was a leading cause of AIS in this group (68.2%). The occlusion sites of the major cerebral arteries included the common carotid artery and internal carotid artery (ICA; 29.6%), middle cerebral artery (52.2%), and basilar artery (7.6%). Recanalization therapy (RT) was performed in 32.0% of patients (IV rt-PA, 20.0%; neuroendovascular therapy, 9.4%; combined, 2.5%). Symptomatic intracerebral hemorrhage within 36 hours with a ≥ 1-point increase in the National Institutes of Health Stroke Scale score occurred in 5.3% of the patients. At 3 months (or at hospital discharge), 29.3% of the patients had a favorable outcome (based on a modified Rankin scale score of 0-2), 23.8% were bedridden, and 15.6% died. After multivariate adjustment, RT was positively associated with a favorable outcome and negatively associated with death, whereas age, baseline National Institutes of Health Stroke Scale score, and ICA occlusion were negatively associated with a favorable outcome and positively associated with death. One-third of the patients with AIS and major cerebral artery occlusion were treated with RT, which was independently associated with favorable outcomes and death. However, 40% of the patients became bedridden or died during the post-alteplase, pre-MERCI era in Japan.

Stent-Assisted Coil Embolization of Ruptured Aneurysms in the Acute Stage: Advantages and Disadvantages.

Objective: In the acute stage of ruptured cerebral aneurysms, limited devices are available, making the treatment difficult. We aimed to evaluate the outcomes of the coil embolization with stenting for the ruptured cerebral aneurysms in the acute stage. Methods: We assessed 22 cases treated with stenting among 134 of 169 consecutive patients with subarachnoid hemorrhages undergoing an endovascular treatment between April 2014 and December 2021, of which 134 underwent an embolization during the acute stage. A stent was used in the patients wherein the treatment with the balloon-assisted or double catheter technique was difficult. Stenting was performed under the loading of two or more antiplatelet agents. Results: The mean age of the patients was 68.9 years, of which five were male and 14 (63.6%) had severe grade (World Federation of Neurosurgeons grade IV, V). The aneurysm site was the anterior communicating artery in four cases, internal carotid artery in nine, middle cerebral artery in two, vertebrobasilar artery in six, and posterior cerebral artery in one. The aneurysm shape was saccular in 13 cases, dissection in seven, and fusiform in two. Stents were used for wide-neck aneurysms in 12 cases, vascular preservation in seven, and rescue in three. The mean maximum diameter was 9.6 mm. The mean neck size was 6.4 mm. Complete occlusion and neck remnant were found in eight and seven cases, respectively. The perioperative complication rate was 45.5% (thromboembolism in five cases, stent occlusion in two, re-bleeding in two, and cerebral hemorrhage in one). The outcomes included modified Rankin Scale 0-2 in seven cases, 4-5 in five, and 6 in nine. Stent-related death occurred in one case. The rate of morbidity and mortality was 18.2%. Although stents were used in the acute stage of rupture, they were used for the right reasons. However, a high rate of complications occurred: two cases of re-bleeding, in which an incomplete occlusion was a factor. Conclusion: Stent placement in patients with the acute ruptured cerebral aneurysms should be carefully determined and efforts should be made to reduce the embolic and hemorrhagic complications. However, it may be an effective treatment option when other options could be extremely difficult.

Carotid artery stenting for stenosis after carotid artery replacement: An illustrative case report.

Background: There are few reports on the treatment of carotid artery stenosis after arterial vessel replacement. We report and discuss an illustrative case of carotid artery stenting (CAS) performed for stenosis after carotid artery replacement. Case Description: A woman in her 20s experienced injury to the right carotid artery during an operation for removal of a carotid body tumor 6 years before presentation. The right common carotid artery and internal carotid artery were replaced with an artificial vessel graft at that time. Intraluminal stenosis in the graft was not identified 3 years after surgery; however, 4 years after surgery, stenosis was recognized at the non-anastomotic site inside the artificial vessel graft. Subsequently, antiplatelet therapy was initiated. The stenosis was noted to progress gradually in follow-up appointments. Therefore, we decided to intervene because of the patient's young age and the risk of long-term hemodynamic stress. Angiography revealed pseudo-occlusion in the artificial vessel. Percutaneous transluminal angioplasty was performed for stenosis with distal protection; subsequently, CAS was performed. The patient was discharged without neurological deficits 4 days after the operation, and no apparent restenosis was observed as of the 1-year follow-up. Conclusion: Stenosis after cervical artery replacement can be safely treated with CAS. Inflation pressure and stent should be selected according to the pathology of the stenosis.

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.

Complex arteriovenous fistulas at C1 causing hematomyelia through aneurysmal rupture of a feeder from the anterior spinal artery.

A 64-year-old woman presented with left occipital headache and right dissociated sensory loss due to hematomyelia on the left ventral side of C1 caused by rupture of an aneurysm on one of the feeders extending from the anterior spinal artery to complex epidural or dural and intradural arteriovenous fistulas (AVFs). Branches from the left occipital and ascending pharyngeal arteries and those from the left C2 radicular, left posterior spinal and anterior spinal arteries formed these multiple shunts, linking with a common venous drain flowing into the right petrosal vein. Surgical interception of all the shunts was achieved, making it unnecessary to directly treat the aneurysm in the spinal cord. The feeders, aneurysm and AVFs were not visualized on postoperative angiography, and the patient returned to a normal working life.

A Case of Pterygopalatine Fossa Arteriovenous Malformation Treated by Transarterial Embolization Using a Dual-Lumen Balloon Catheter.

Objective: We report a rare case of pterygopalatine fossa arterial venous shunt disease with venous congestion of the superior ophthalmic vein (SOV) that was treated by transarterial balloon-assisted embolization. Case Presentation: A 57-year-old man presented with congestion of the right bulbar conjunctiva, protrusion, and swelling of the right eyelid was admitted to our hospital. Angiography demonstrated an arteriovenous fistula (AVF) forming small congregated vessels in the pterygopalatine fossa fed by the branch of the ophthalmic artery (OA) and artery of the superior orbital fissure, draining into the SOV via the inferior ophthalmic vein (IOV). From the artery of the superior orbital fissure, transarterial embolization (TAE) with ONYX using a dual-lumen balloon catheter was performed. The patient was treated without complications. Conclusion: TAE using transarterial balloon-assisted embolization with ONYX is effective for periorbital arteriovenous shunts, although special care is necessary to prevent the migration of ONYX into the OA.