Traumatic arteriovenous fistula of the middle meningeal artery treated with selective coil embolization: A case report.

Background: Dural arteriovenous fistulas (AVFs) are reportedly induced by trauma. We report a rare case of traumatic AVF with a direct shunt from the middle meningeal artery (MMA) to the middle meningeal vein (MMV) and multiple drainage routes after head trauma. The patient was effectively treated with selective coil embolization alone without liquid embolic material. Case Description: A 56-year-old woman was admitted to the emergency department with mild disturbance of consciousness caused by a head contusion after alcohol consumption. She exhibited impaired consciousness with a Glasgow coma scale score of 14 (E4V4M6), complained of headache, and presented with a hemorrhage in the left ear. Computed tomography suggested a skull fracture and cerebral hemorrhage. Magnetic resonance imaging conducted on the 4th day after the injury indicated shunt disease with a feeder in the right MMA. Cerebral angiography on the 7th day suggested a direct shunt from the right MMA to the MMV aligned with the temporal bone fracture line, with multiple drainage route perfusion. Coil embolization was performed on the 14th day to occlude the shunt point selectively. In the final image, the MMA was absent, and the MMV, superior sagittal sinus, or pterygoid plexus was not visible through the shunt. Her symptoms improved, and she was discharged on the 20th day and did not exhibit recurrence at the 1-year follow-up. Conclusion: AVF with a direct shunt from the MMA to MMV after head trauma can be effectively and safely treated with coil embolization alone, despite the need for long-term postoperative follow-up.

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.

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.

[Carotid Artery Stenosis:Endovascular Techniques and Devices].

The increase in the number of carotid artery stenting cases can be attributed to a decrease in complications owing to the evolution of devices. In this procedure, the choice of the protection device and stent for each case is the main concern. Embolic protection devices(EPD)that prevent distal embolization can be divided into proximal and distal types. Previously, balloon-type devices were used as distal EPDs; however, since they are no longer available, filter-type devices are now mainstream. Carotid stents are also divided into open- and closed-cell types. Therefore, this review describes the characteristics of each device in the actual cases at our hospital.

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.

Primary results of mechanical thrombectomy for acute ischemic stroke: The K-NET registry in the Japanese metropolitan area.

BACKGROUND: Endovascular treatment (EVT) for acute large vessel occlusion has proven to be effective in randomized controlled trials. We conducted a prospective cohort study to evaluate the real-world efficacy of EVT in a metropolitan area with a large number of comprehensive stroke centers and to compare it with the results of other registries and randomized controlled trials (RCTs). METHODS: We analyzed the Kanagawa Intravenous and Endovascular Treatment of Acute Ischemic Stroke registry, a prospective, multicenter observational study of patients treated by EVT and/or intravenous tissue-type plasminogen activator (tPA). Of the 2488 patients enrolled from January 2018 to June 2020, 1764 patients treated with EVT were included. The primary outcome was a good outcome, which was defined as a modified Rankin Scale (mRS) of 0-2 at 90 days. Secondary analysis included predicting a good outcome using multivariate logistic regression analysis. RESULTS: The median age was 77 years, and the median National Institute of Health Stroke Scale (NIHSS) score was 18. Pretreatment mRS score 0-2 was 87%, and direct transport was 92%. The rate of occlusion in anterior circulation was 90.3%. Successful recanalization was observed in 88.7%. The median time from onset to recanalization was 193 min. Good outcomes at 90 days were 43.3% in anterior circulation and 41.9% in posterior circulation. Overall mortality was 12.6%. Significant predictors for a good outcome were as follows: age, male, direct transfer, NIHSS score, Alberta Stroke Program Early Computed Tomography Score, intravenous tPA, and successful recanalization. CONCLUSION: EVT in routine clinical use in a metropolitan area showed comparable good outcomes and lower mortality compared to previous studies, despite the high proportion of patients with older age, pretreatment mRS score of >2, posterior circulation occlusion, and higher NIHSS. Those results may have been associated with more direct transport and faster onset-to-recanalization times.

Delayed rupture of a large intracranial internal carotid artery aneurysm after flow diverter placement.

Background: Delayed rupture after flow diverter (FD) placement is a serious complication, and often it leads to death; however, the exact mechanism leading to the rupture remains unclear. Therefore, in this case, study, we report a case of delayed rupture after FD placement and discuss its causes. Case Description: This study presents the case of a 69-year-old female with multiple aneurysms who underwent FD placement with coil embolization for a large intracranial internal carotid artery aneurysm. Postoperatively, the patient had no significant symptoms, and angiography and magnetic resonance imaging revealed decreased intra-aneurysmal blood flow. However, on the 3rd postoperative day, she developed a sudden disturbance of consciousness. Computed tomography revealed a massive subarachnoid hemorrhage, diagnosed as a delayed rupture. We decided to withhold therapy due to her serious condition. Previous studies have suggested that hemodynamic mechanisms can cause delayed aneurysm rupture. Based on the computational fluid dynamics (CFD) of the aneurysm, we suggest that an increase in intra-aneurysmal pressure after FD placement may have caused the delayed rupture. Conclusion: Preoperative CFD analysis may help evaluate the risk of delayed rupture for large aneurysms with a high inflow from the parent vessel.

Fluid-attenuated inversion recovery vascular hyperintensity-diffusion-weighted imaging mismatch and functional outcome after endovascular reperfusion therapy for acute ischemic stroke.

BACKGROUND: Fluid-attenuated inversion recovery vascular hyperintensity (FVH) outside of the diffusion-weighted imaging (DWI) lesion, termed FVH-DWI mismatch, may represent penumbral tissue with good collateral status. METHODS: Consecutive patients who underwent endovascular reperfusion therapy (EVT) for acute internal carotid artery (ICA) or middle cerebral artery (MCA)-M1 occlusion were enrolled. FVH-DWI mismatch score was defined as the number of cortical Alberta Stroke Program Early CT Score areas (I and M1 to M6) that involved FVH but no DWI lesion (0 to 7 points). The outcome measure was set as good functional outcome, defined as a modified Rankin Scale score of 0 to 2, at 90 days after onset. RESULTS: Of 196 consecutive patients who underwent EVT for acute ICA or MCA-M1 occlusion, 32 without brain MRI before EVT were excluded, and the remaining 164 were analyzed. The median FVH-DWI mismatch score was 2 (interquartile range, 0 to 4). At 90 days after EVT, 2 patients were lost-to follow-up, and 73 had good functional outcome. The frequency of good functional outcome at 90 days after EVT increased significantly with increasing FVH-DWI mismatch score (P for trend <0.001). FVH-DWI mismatch score was independently associated with good functional outcome at 90 days after onset (adjusted odds ratio per 1 point,1.46; 95% confidence interval, 1.15-1.89). CONCLUSIONS: Patients with large FVH-DWI mismatch had good functional outcome after EVT for acute ICA or MCA-M1 occlusion.

Two patients of visual disturbance and optic perineuritis after placement of a flow diverter.

The pathogenesis of new visual symptoms after flow diverter stent placement in the ophthalmic artery for internal carotid artery aneurysms remains unclear. We report two cases of patients who developed visual field disturbance and decreased visual acuity following flow diverter placement. The "doughnut sign" was found around the optic nerve on magnetic resonance imaging. The patients had progressive visual field defects and impairment on the side where the flow diverter was placed. Short tau inversion recovery coronal images showed a doughnut-shaped high-signal around the optic nerve on the affected side. Both patients were treated with steroid pulse therapy, and 1 received endovascular therapy. Their symptoms gradually improved, and the "doughnut sign" disappeared. The "doughnut sign" observed around the optic nerve on magnetic resonance imaging may be found alongside visual disturbance symptoms after paraclinoid aneurysm treatment. It is recommended that short tau inversion recovery sequences be performed preoperatively in patients presenting with visual impairment and in whom the possibility of postoperative exacerbation is suspected.

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.

Intraplaque high-intensity signal on time-of-flight magnetic resonance angiography and restenosis after carotid artery stenting.

OBJECTIVE: To test the hypothesis that intraplaque hemorrhage is a predictor of restenosis after carotid artery stenting (CAS), the association between intraplaque high-intensity signal (HIS) on time-of-flight MR angiography (TOF-MRA), as a marker of intraplaque hemorrhage, and restenosis after CAS was assessed in the present observational study. METHODS: Consecutive patients who underwent initial CAS for atherosclerotic stenosis in the cervical internal carotid artery in the authors' department were enrolled. Of these, patients without preprocedural cervical TOF-MRA were excluded. Outcome measures were ≥ 50% restenosis, defined as a peak systolic velocity of > 1.3 m/sec; or occlusion and ≥ 70% restenosis, defined as a peak systolic velocity of > 2.1 m/sec; or occlusion on carotid duplex ultrasound. RESULTS: Of 230 consecutive patients who underwent initial CAS, 22 without preprocedural cervical TOF-MRA were excluded. Of the remaining 208 patients (mean age 73 years; 33 women), 46 had intraplaque HIS. Ultrasound follow-up was not performed in 4 patients. The median follow-up duration was 3.2 years (interquartile range 1.7-5.1 years). During the follow-up period, 102 patients had ≥ 50% restenosis and 36 had ≥ 70% restenosis. Intraplaque HIS was significantly associated with increased risk of ≥ 50% restenosis (adjusted hazard ratio 2.18; 95% CI 1.28-3.68) and ≥ 70% restenosis (adjusted hazard ratio 3.12; 95% CI 1.32-7.52). CONCLUSIONS: Intraplaque HIS on TOF-MRA was associated with increased risk of restenosis after CAS. The present results indicate that intraplaque hemorrhage is a predictor of restenosis after CAS.

Efficacy of combined use of a stent retriever and aspiration catheter in mechanical thrombectomy for acute ischemic stroke.

BACKGROUND: The efficacy of combined stent retriever (SR) and aspiration catheter (AC; combined technique: CBT) use for acute ischemic stroke (AIS) is unclear. We investigated the safety and efficacy of single-unit CBT (SCBT)-retrieving the thrombus as a single unit with SR and AC into the guide catheter-compared with single use of either SR or contact aspiration (CA). METHODS: We analysed 763 consecutive patients who underwent mechanical thrombectomy for AIS between January 2013 and January 2020, at six comprehensive stroke centers. Patients were divided into SCBT and single device (SR/CA) groups. The successful recanalization with first pass (SRFP) and other procedural outcomes were compared between groups. RESULTS: Overall, 240 SCBT and 301 SR/CA (SR 128, CA 173) patients were analyzed. SRFP (modified Thrombolysis In Cerebral Infarction (mTICI) ≥2c, 43.3% vs 27.9%, p<0.001; mTICI 3, 35.8% vs 25.5%, p=0.009) and final mTICI ≥2b recanalization (89.1% vs 82.0%, p=0.020) rates were significantly higher, puncture-to-reperfusion time was shorter (median (IQR) 43 (31.5-69) vs 55 (38-82.2) min, p<0.001), and the number of passes were fewer (mean±SD 1.72±0.92 vs 1.99±1.01, p<0.001) in the SCBT group. Procedural complications were similar between the groups. In subgroup analysis, SCBT was more effective in women, cardioembolic stroke patients, and internal carotid artery and M2 occlusions. CONCLUSIONS: SCBT increases the SRFP rate and shortens the puncture-to-reperfusion time without increasing procedural complications.

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.

Mechanical thrombectomy and carotid artery stenting for stenosis of the internal carotid artery with free-floating thrombosis: illustrative case.

BACKGROUND: The authors report a case in which mechanical thrombectomy and carotid artery stenting (CAS) were performed for acute cerebral infarction with free-floating thrombosis (FFT) in left internal carotid artery (ICA) stenosis. Good results were obtained. OBSERVATIONS: A 63-year-old man developed sudden disturbance of consciousness and right hemiplegia. He was transported to the authors' hospital by an emergency vehicle. Head magnetic resonance imaging showed acute cerebral infarction in the left middle cerebral artery region, and magnetic resonance angiography showed poor vascular flow beyond the left ICA. Emergency angiography revealed severe stenosis at the origin of the left ICA and a free-floating thrombus attached to the stenosis and extending to the peripheral side. Percutaneous transluminal angioplasty (PTA) was performed on the stenosis with proximal protection, the thrombus was aspirated under reversal flow, and CAS was performed without exacerbation of clinical symptoms. LESSONS: PTA, thrombus aspiration, and CAS under reversal flow may be effective treatments for FFT caused by ICA stenosis.

Endovascular Treatment for Dural Arteriovenous Fistulae Using a Sinus Protection Balloon to Maintain the Patency of the Dural Sinus.

We introduce our technique to treat dural arteriovenous fistulae (dAVFe) under sinus balloon protection. The Kaneka Shoryu 7 × 7 mm balloon was used for sinus occlusion. Initially, the balloon was inflated slowly using 1.5-2.0 mL of saline on the table. A 6F guiding catheter was navigated into the proximal portion of the lesion from the jugular vein of the affected side. The balloon catheter was introduced to the point occluding the shunt. The balloon was temporarily inflated to determine the occlusion point without occluding the outlet of the vein of Labbe. ONYX injection was started from the microcatheter located at just proximal to the shunt point under sinus balloon occlusion. ONYX penetrated the feeding arteries in an antegrade and retrograde manner. After the penetration of ONYX into each feeding artery, the inflated balloon was temporarily deflated to examine the residual shunt. If a small shunt remained, the balloon was inflated again and ONYX injection was continued. To cure dAVF, the location of the balloon is important. The guiding catheter should be placed just proximal to the shunt and the balloon catheter should be gently pulled to stabilize the balloon position.

Cavernous Sinus Dural Arteriovenous Fistulas: General Aspects.

Cavernous sinus (CS) dural arteriovenous fistulas (AVF), which are most common in middle-aged females, present with benign symptoms such as exophthalmos, chemosis, and orbital bruit. Benign CS dural AVF without cortical venous drainage (CVD) have the rare potential for development of CVD with neurological symptoms, even without treatment. On the other hand, aggressive type AVF with CVD can cause more aggressive symptoms such as cerebral hemorrhage. As symptoms are highly related to the drainage pattern, it is important to understand the anatomy of the CS itself, shunt point, and draining vein when treating the lesion. In general, the drainage route is gradually diminished by thrombosis and compartmentalization within the CS according to progression of the angiographical stage. At the restrictive stage, the disease is usually treated by endovascular treatment, particularly transvenous embolization.

Ruptured Cerebral Arteriovenous Malformation During Fifth Pregnancy: Case Report and Literature Review.

BACKGROUND: Whether the risk of rupture of a cerebral arteriovenous malformation (AVM) increases during pregnancy remains controversial. Moreover, it is unclear whether the number of pregnancies correlates with AVM rupture risk. We report a case of ruptured AVM during the fifth pregnancy. CASE DESCRIPTION: A 34-year-old woman presenting sudden headache and vomiting was admitted to our hospital. Neuroimaging revealed a subarachnoid hemorrhage due to a ruptured AVM in the right temporal lobe. She was pregnant (9 weeks and 1 day), and she had previously experienced 4 normal vaginal deliveries (gravidity and parity G4P4) without complications. Elective treatment including neuroendovascular and direct surgery was performed, and the AVM was safely resected (at 15 weeks, 6 days of pregnancy). She underwent elective caesarean section without complications 151 days after the AVM resection (at 37 weeks, 1 day of pregnancy), and the baby was healthy. CONCLUSIONS: This report suggests that the risk of AVM rupture persists even after multiple deliveries. Intracranial hemorrhage should be suspected in pregnant patients who underwent multiple deliveries, and a rapid diagnosis and appropriate treatment are necessary.

Efficacy and Safety of REVIVE SE Thrombectomy Device for Acute Ischemic Stroke: River JAPAN (Reperfuse Ischemic Vessels with Endovascular Recanalization Device in Japan).

REVIVE SE (REVIVE) is a closed-ended, self-expanding stent retriever used in the RIVER JAPAN study. We present our early experience with REVIVE for revascularization of acute ischemic stroke (AIS) in patients who have failed or are ineligible for intravenous recombinant tissue plasminogen activator treatment. This prospective, single-arm, non-randomized, multicenter registry study followed up patients undergoing mechanical thrombectomy with REVIVE for 90 days. The primary endpoint was a post-procedure Thrombolysis in Cerebral Infarction (TICI) score ≥2a. Secondary endpoints were clot migration/embolization; recanalization without symptomatic intracranial hemorrhage (ICH) at 24 h; symptomatic ICH; good neurological outcome (modified Rankin Scale score ≤2 National Institute of Health Stroke Scale (NIHSS) score decrease ≥10) at day 90; device- or procedure-related serious adverse events (SAEs) and mortality at day 90. To confirm non-inferiority of REVIVE, results were compared with historical data of the Merci Retriever. About 49 patients were enrolled (median age 73 years; males 46.9%; middle cerebral artery (MCA) occlusion 83.7%; median NIHSS score 17). A post-procedure TICI score ≥2a was observed in 73.5% (36/49, 95% confidence interval [CI] 58.9-85.1) of patients. No post-procedural clot migration/embolization events occurred. Successful recanalization without symptomatic ICH was observed in 62.5% (30/48, 95% CI 47.4-76.0). The good neurological outcome was achieved in 66.7% (32/48) patients. Symptomatic ICH and device- or procedure-related SAEs were reported in 6.3% and 12.2% of patients, respectively. Two deaths were reported. REVIVE demonstrated equivalent efficacy and safety as the Merci Retriever. Results suggest that REVIVE is effective and safe in recanalizing occluded intracranial arteries in AIS.

Impact of antithrombotic treatment on clinical outcomes after craniotomy for unruptured intracranial aneurysm.

OBJECTIVE: Patients receiving antithrombotic treatment occasionally undergo craniotomy. We aimed to explore the impact of perioperative use of antithrombotic agents on the occurrence of surgical complications and clinical outcomes in patients with unruptured intracranial aneurysm (UIA). PATIENTS AND METHODS: We retrospectively analyzed 401 consecutive patients who had undergone craniotomy for UIA at our institution between January 2006 and December 2016. Patients were divided into two groups: those who received oral antiplatelet and/or anticoagulant agents during the perioperative period (antithrombotic treatment group, n=45); and those who did not (no antithrombotic treatment group, n=356). In the antithrombotic treatment group, 40 patients received antiplatelet alone, 2 received anticoagulant alone, and 3 received antiplatelet plus anticoagulant. RESULTS: The two groups showed no significant differences in mortality, morbidity, or occurrence of symptomatic brain infarction, but intracranial hemorrhage was more frequent in the antithrombotic treatment group than in the no antithrombotic treatment group (p=0.0187). Multivariate analysis revealed posterior location of the aneurysm (odds ratio (OR), 8.10; 95% confidence interval (CI), 2.77-23.68; p=0.0001) and surgical procedure (OR, 5.48; 95%CI, 1.68-17.86; p=0.0048) as significantly correlated with severe morbidity, and intracranial hemorrhage as correlated significantly with antithrombotic treatment (OR, 3.83; 95%CI, 1.36-10.76; p=0.0110). CONCLUSIONS: This study provides important information about the occurrence of intracranial hemorrhage and clinical outcomes in patients undergoing antithrombotic treatment during the perioperative period of craniotomy for UIA.

Interaction between the stent strut and thrombus characterized by contrast-enhanced high-resolution cone beam CT during deployment of the Solitaire stent retriever.

BACKGROUND: The mechanism by which a stent retriever removes intraluminal thrombus from an occluded vessel in humans has not previously been studied. This study performed contrast-enhanced high-resolution cone beam CT (CE-HRCBCT) during deployment of the stent retriever to observe the interaction between the strut and intraluminal thrombus intraoperatively. We also discuss the mechanism by which the thrombus is retrieved. METHODS: In 11 patients, mechanical thrombectomy was performed with a Solitaire stent retriever. The presence or absence of flow restoration (FR) was evaluated immediately and at least 5 min after deployment. Stent retriever findings on CE-HRCBCT were divided into two groups: (1) complete expansion; and (2) incomplete expansion. RESULTS: FR was observed in all 11 cases (100%) immediately after deployment of the Solitaire stent retriever. Complete expansion was observed in only one case and incomplete expansion was observed in 10 cases. The thrombus was observed mainly near to or outside the strut of the stent retriever by CE-HRCBCT. Loss of FR was seen in only one of the 11 cases. Regardless of this, successful recanalization was achieved with only the stent retriever in nine cases. CONCLUSIONS: CE-HRCBCT showed that the Solitaire stent retriever rarely expanded fully and the thrombus was mainly near to or outside the strut. It may not be necessary to wait a long time to allow the stent to expand fully into the thrombus because the main capture mechanism seems to be engagement of the clot between the crossings of the struts of the Solitaire.