Transvenous embolization via the facial vein for intraorbital dural arteriovenous fistula: illustrative case.

BACKGROUND: Intraorbital arteriovenous fistula (IOAVF) is a rare type of intracranial fistula that presents with ocular signs similar to those of cavernous sinus dural arteriovenous fistula. The treatment of IOAVF is based on the vascular architecture of each case due to its infrequent occurrence. The authors report the case of an IOAVF that was successfully treated with embolization via the facial vein, with good outcomes. OBSERVATIONS: A 78-year-old woman presented with left eyelid swelling, pulsatile ocular protrusion, and left ocular conjunctival hyperemia. Ophthalmological evaluation revealed elevated intraocular pressure; time-of-flight magnetic resonance angiography revealed a dilated left superior ophthalmic vein. Digital subtraction angiography showed an arteriovenous shunt in the left superior orbital fissure, which was treated using transvenous coil embolization. The patient experienced immediate improvement in left ocular protrusion and conjunctival hyperemia. Ophthalmological evaluation 1 month after treatment showed normal intraocular pressure in the left eye. No neurological symptoms were observed, and there was no recurrence of the arteriovenous shunt 3 months postoperatively. LESSONS: The authors report a rare case of IOAVF treated with embolization via the facial vein with a good outcome. A thorough understanding of the vascular architecture using three-dimensional images is useful for determining endovascular access and procedures.

The preoperative focal cerebral blood flow status may be associated with slow flow in the bypass graft after combined surgery for moyamoya disease.

Background: The aim of this study was to investigate the association between early postoperative slow flow in bypass grafts and preoperative focal cerebral blood flow (CBF) in patients who underwent combined surgery for moyamoya disease (MMD). Methods: The subjects were 18 patients (22 surgeries) who underwent single photon emission computed tomography (SPECT) before surgery. The CBF value of the middle cerebral artery territory was extracted from the SPECT data, and the value relative to the ipsilateral cerebellar CBF (relative CBF, or RCBF) was calculated. The association between RCBF and early postoperative slow flow in the bypass graft was investigated. In addition, the correlation between the revascularization effect and preoperative RCBF was analyzed. Results: In four of 22 surgeries (18.2%), slow flow in the bypass graft was identified in the early postoperative period. Preoperative RCBF in the slow flow and patent groups was 0.86 ± 0.15 and 0.87 ± 0.15, respectively, with no significant difference (P = 0.72). The signal intensity of four slow-flowed bypasses was improved in all cases on magnetic resonance angiography images captured during the chronic phase (mean of 3.3 months postoperatively). The revascularization scores were 2 ± 0.82 and 2.1 ± 0.68 in the slow flow and patent groups, respectively, and did not differ significantly (P = 0.78). A significant correlation was not observed between preoperative RCBF and the revascularization effect. Conclusion: No significant association was observed between preoperative RCBF and early postoperative slow flow in bypass grafts in patients with MMD undergoing combined surgery. Given the high rate of improved depiction of slow-flowed bypass in the chronic postoperative phase, the conceptual significance of an opportune surgical intervention is to maintain CBF by supporting the patient's own intracranial-extracranial conversion function.

Surgical disconnection of a hypoglossal canal dural arteriovenous fistula demonstrating rapid progression of medulla oblongata disturbance: illustrative case.

BACKGROUND: Dural arteriovenous fistulas of the hypoglossal canal (HCDAVFs) with dominant drainage to perimedullary veins are extremely rare. These patients are prone to develop slow and progressive myelopathy, however, their clinical course has not been fully elucidated. We report an unusual case of HCDAVF in which the patient demonstrated rapid progression of hemiplegia and respiratory insufficiency. OBSERVATIONS: An 82-year-old woman demonstrated motor weakness of the left extremities. T2-weighted magnetic resonance imaging showed a high intensity area in the right medulla oblongata and angiography revealed HCDAVF with dominant drainage to the anterior medullary vein through the anterior condylar vein. Within 3 days, her hemiparesis and respiratory function worsened, and she needed mechanical ventilation. Considering that venous congestion in the medulla oblongata could cause the symptoms, we immediately performed surgical obliteration of the anterior condylar vein. The disappearance of HCDAVF was confirmed by angiography and the patient was weaned from mechanical ventilation 3 days postoperatively. Her left hemiplegia gradually resolved and she was independent in daily life 8 months after the operation. LESSONS: HCDAVFs with dominant drainage to the perimedullary veins can demonstrate rapid progression of medulla oblongata disturbance. Early disconnection should be considered to provide an opportunity for substantial recovery.

Coexistence of a Dural Arteriovenous Fistula and Pial Arteriovenous Malformation Sharing a Common Drainer.

In cases of a dural arteriovenous fistula (AVF) with a pial arterial supply, postoperative hemorrhagic complications occur frequently. Six cases in which patients were diagnosed with a coexisting dural AVF and pial arteriovenous malformation (AVM) sharing a common drainer are presented. These cases were initially thought to be dural AVFs with pial arterial supplies, but careful examination of preoperative images showed that a pial AVM coexisted near the dural AVF, and that both shared a common drainer. The coexistence of a pial AVM is difficult to notice during surgery; for this reason, determining the presence of a pial AVM on preoperative imaging is essential to safely treat a dural AVF with a pial arterial supply. The details of each case, specifically, the diagnostic evidence for this condition (coexisting dural AVF and pial AVM sharing a common drainer), as well as imaging findings that should be noted, are presented.

Non-brain-exposure Exoscopic and Endoscopic Volume Reduction Surgery for Benign Meningioma En Plaque in an Elderly Patient: A Case Report.

Meningioma en plaque (MEP) often needs invasive surgery to resect totally because of its widespread proliferation along the dura mater. We report a minimally invasive surgical technique for non-brain-exposure exoscopic and endoscopic volume reduction in an elderly patient with MEP. An 83-year-old woman presented with gait disturbance and cognitive dysfunction that had progressed over 6 months. Magnetic resonance imaging (MRI) revealed a large MEP on the right frontal lobe with peritumoral edema. On confirming the benign nature of the tumor (WHO grade 1) by biopsy, the main feeders and tumor were transarterially embolized. Volume reduction surgery was performed under the assistance of an exoscope and an endoscope while being careful not to expose and damage the cortex. Her symptoms completely resolved postoperatively. This surgical technique without exposing the brain may be a treatment choice for elderly patients with benign symptomatic convexity MEP.

Long-term Outcomes of Carotid Artery Stenting: A Single-center Experience.

The long-term prophylactic effect of carotid artery stenting (CAS) remains incompletely elucidated. We evaluated outcomes of CAS at our institution to determine the safety and efficacy of CAS in real-world settings. We retrospectively analyzed 73 patients who underwent CAS from 2006 to 2013. Periprocedural results were compared between asymptomatic and symptomatic carotid stenosis groups. The primary endpoint was a composite of ipsilateral stroke, death, and carotid artery restenosis beyond 30 days and within 5 years after the first procedure. The average age was 72.2 years with a majority of male subjects (84.9%). Twenty-seven patients (37%) were asymptomatic. Incidence of periprocedural adverse events and mRS ≤2 at 30 days after CAS were not significantly different between groups (P = 0.14 and 0.07, respectively). CAS was unsuccessful in three patients and one post-procedural minor stroke occurred. Therefore, 69 patients were included in the long-term study. The rate of occurrence of the primary endpoint was 21.7%. Ipsilateral ischemic stroke occurred in one patient, which was due to cardiogenic embolus. Nine patients died, and cancer was the most frequent cause. Five in-stent restenoses were observed. All patients with restenosis underwent additional CAS without any occurrence of stroke. This study revealed the safety and long-term efficacy of CAS in a real-world setting. Routine follow-up is also important for detecting carotid artery restenosis.

Experimental study of coil delivery wire insertion force in intracranial aneurysm embolization: force discrepancy generated inside the microcatheter through that coil delivery wire passes.

In endovascular coil embolization for intracranial aneurysms, as coils are filled in the aneurysm and the stage of procedure is advanced, the force to push forward the coil delivery wire (insertion force) increases. However, the coil insertion force that interventionist's felt at his fingertips does not directly reflect the stress of the aneurysm and is affected by the resistance generated inside the microcatheter through that the wire passes. The authors evaluated this force discrepancy by subtracting the loading force at the tip of delivery wire from the insertion force of delivery wire and examined the relationship among them. Experiments were performed with the device that applies a constant loading force to the delivery wire tip with the coil removed. A force gauge was connected to the end-tip of the delivery wire to measure the insertion force. The force was measured by changing delivery wire in different coil brands and the conditions of microcatheter (straight or bent position). The results demonstrated that force discrepancy generated inside the microcatheter increased as the loading force increased in a linear relationship. Different coil delivery wires produced differences in the way that force discrepancy changed, thus reflecting the properties of each wire. Microcatheters with more curvature were associated with a higher force discrepancy. In conclusions, as the loading force increases, the force discrepancy increases, and it means that the coil insertion force that the interventionist feels at his fingertips also increases. This force discrepancy is impacted by the delivery wire properties and microcatheter curvature.

Association between CYP2C19 genotype and the additional effect of cilostazol to clopidogrel resistance in neuroendovascular therapy.

We investigated the association between CYP2C19 genotype and additional effect of cilostazol on clopidogrel resistance (CR) in neuroendovascular therapy. Between January 2012 and January 2016, 447 consecutive patients were administered with 75-mg cilostazol/day. The VerifyNow System was used for evaluating P2Y12 reaction units (PRU) > 230 and/or percentage inhibition of platelet function (% Inhibition) ≤ 20 as CR. Among 158 patients with CR, 31 were administered with additional 100- or 200-mg cilostazol/day and their platelet function was evaluated. According to CYP2C19 genotypes revealed using the Spartan RX and DNeasy Blood & Tissue Kit, patients were classified into three phenotypic groups: extensive metabolizer (EM, three patients), intermediate metabolizer (IM, 12 patients), and poor metabolizer (PM, 16 patients). Administration of additional cilostazol decreased PRU (EM group: 160.7 ± 85.2 after vs 278.3 ± 40.1 before, P = 0.15; IM group: 205.6 ± 74.0 vs 254.3 ± 35.0, P = 0.02; and PM group: 227.8 ± 52.2 vs 282.1 ± 30.4, P = 0.003), and increased % Inhibition (EM group: 40.0 ± 27.9 vs 9.3 ± 3.8, P = 0.25; IM group: 31.4 ± 18.0 vs 11.8 ± 8.2, P = 0.001; and PM group: 24.6 ± 15.0 vs 10.4 ± 9.3, P = 0.001). However, the rate of normalized-clopidogrel response, thromboembolic lesions, and bleeding complications were not significantly different among the three groups. Thus, the addition of cilostazol was effective on CR in terms of PRU, % Inhibition, rate of change of normalized-clopidogrel response, thromboembolic events, and bleeding complications irrespective of phenotype.

High-resolution cone beam CT for evaluation of vascular channel in intracranial partial thrombosed aneurysm.

The authors present a 60-year-old man with a partially thrombosed, intracranial vertebral artery aneurysm. A vascular channel in intra-aneurysmal thrombus was effectively identified with high-resolution cone beam CT (DynaCT Micro: Siemens Medical Solutions, Erlangen, Germany). Pre-procedural vertebral angiogram implied a perforating artery arising from near neck of the aneurysm and DynaCT Micro performed before approaching to the lesion demonstrated a vascular channel running in intra-aneurysmal thrombus which could not be distinguished from perforators with other imaging modalities. It was confirmed that perforators around the aneurysm were not identified and safely treated the aneurysm with stent-assisted coil embolization. High-resolution cone beam CT is enable to sharply visualize vessel lumens, thrombus, and intra-thrombus structures, and is useful to identify a vascular channel in intracranial partially thrombosed aneurysm.

Clinical Application of Insertion Force Sensor System for Coil Embolization of Intracranial Aneurysms.

INTRODUCTION: In endovascular embolization for intracranial aneurysms, it is important to properly control the coil insertion force. However, the force can only be subjectively detected by the subtle feedback experienced by neurointerventionists at their fingertips. The authors envisioned a system that would objectively sense and quantify that force. In this article, coil insertion force was measured in cases of intracranial aneurysm using this sensor, and its actual clinical application was investigated. METHODS: The sensor consists of a hemostatic valve (Y-connector). A little flexure was intentionally added in the device, and it creates a bend in the delivery wire. The sensor measures the change in the position of the bent wire depending on the insertion force and translates it into a force value. Using this, embolization was performed for 10 unruptured intracranial aneurysms. RESULTS: The sensor adequately recorded the force, and it reflected the operators' usual clinical experience. The presence of the sensor did not affect the procedures. The sensor enabled the operators to objectively note and evaluate the insertion force and better cooperative handling was possible. Additionally, other members of the intervention team shared the information. Force records demonstrated the characteristic patterns according to every stage of coiling (framing, filling, and finishing). CONCLUSIONS: The force sensor system adequately measured coil insertion force in intracranial aneurysm coil embolization procedures. The safety of this sensor was demonstrated in clinical application for the limited number of patients. This system is useful adjunct for assisting during coil embolization for an intracranial aneurysm.

Relationship between low response to clopidogrel and periprocedural ischemic events with coil embolization for intracranial aneurysms.

OBJECTIVES: Low response to antiplatelet drugs is one of the risk factors for ischemic events. We examined the influence of low response to clopidogrel on symptomatic ischemic events and new ischemic MRI lesions with endovascular intracranial aneurysmal coil embolization. MATERIALS AND METHODS: Between August 2010 and July 2013, 189 procedures in 181 consecutive patients who underwent endovascular coiling and received clopidogrel before treatment were investigated retrospectively. Platelet aggregation activity was examined by VerifyNow analysis. Low response to clopidogrel was defined as P2Y12 reaction units ≥230 in this study. Symptomatic ischemic complications within 30 days and postoperative new ischemic lesions on MRI-diffusion weighted imaging were evaluated. RESULTS: 66 of 189 (34.9%) cases were low responders to clopidogrel. Ischemic complications occurred in 2 of 66 (3.0%) low responders compared with 6 of 123 (4.9%) responders (p=0.72). A new high intensity spot larger than 5 mm was significantly more frequent in low responders (26 of 66; 39.4%) than in responders (26 of 121; 21.2%; p=0.01). On multivariate analysis, independent risk factors for larger new ischemic lesions were low response to clopidogrel, smokers, posterior location, and aneurysms with a larger neck. CONCLUSIONS: Low response to clopidogrel had little effect on clinical outcome although it increased asymptomatic large ischemic lesions in this cohort.

Stereotactic Radiosurgery as the Initial Treatment for Patients with Nonfunctioning Pituitary Adenomas.

OBJECTIVE: The aim of this study was to confirm the efficacy and safety of stereotactic radiosurgery as the initial treatment for patients with nonfunctioning pituitary adenomas (NFPAs) and to decide the optimum dose to achieve long-term tumor control as well as preservation of pituitary endocrine function. METHODS: The study was a single-center retrospective analysis of 16 patients with primary NFPAs that were treated with gamma knife surgery (GKS). Fifteen of 16 NFPAs were growing to the suprasellar region and slightly compressing or very close to the optic apparatus. Initial GKS was selected to avoid visual disturbance caused by further tumor growth that would require surgical resection under general anesthesia. The median tumor volume was 2.0 cm(3), and the median tumor margin dose was 15 Gy. RESULTS: The median clinical follow-up period was 98 months. The last follow-up images demonstrated tumor regression in 15 patients and stable tumor in 1. No patient developed tumor progression. One patient who had pituitary apoplexy before treatment required hormone replacements 2 years after GKS. The other patients did not experience pituitary insufficiency requiring hormone-replacement therapy during the clinical follow-up period. No patient developed cranial nerve injury or radiation-induced neoplasm. CONCLUSIONS: GKS is a safe and effective treatment option in patients with primary NFPAs, especially for patients with advanced age or comorbidity. Attention should be paid to late adverse radiation effects such as hypopituitarism, optic neuropathy, and radiation-induced neoplasms. However, stereotactic radiosurgery with a conformal treatment plan sparing the normal pituitary gland will contribute to avoidance of such complications as well as achievement of long-term tumor control.