Development of a Model for Plaque Induction in Rat Carotid Arteries.

Objective Plaque induction through intimal injury using a balloon catheter in small animals and by artificial ligation of the carotid artery in large animals have been reported. However, these reports have not yet succeeded in inducing stable plaques nor creating a high degree of intimal thickening to be used as animal models. We have previously developed a plaque induction model in rats but have failed to obtain a plaque incidence frequency that can be used as a model. Thus, in the current study, we aimed to create a versatile disease model to examine the pharmacokinetics of drug administration, determine the efficacy of treatment, and examine the process of intimal thickening. We also attempted to create an improved model with shorter, more frequent, and more severe intimal thickening. Materials and Methods The common carotid artery of male Wistar rats was surgically exposed and completely ligated with a wire and 6-0 nylon thread. Then, the wire was removed to create a partial ligation. To create a high frequency and high degree of intimal thickening, 72 rats were divided into two groups: a single lesion group with a 0.25-mm wire and a single ligature point, and a tandem lesion group with a 0.3-mm wire and two ligature points. Each group was further divided into normal diet and high cholesterol diet groups. The presence and frequency of intimal thickening were examined for each group after 4, 8, and 16 weeks of growth. Results In the single lesion group, intimal thickening was observed in 42% of the 4-week group and 75% of the 8-week group. In the tandem lesion group, intimal thickening was observed in 75% of the 4-week group and 50% of the 8-week group. In addition, 50% of the individuals reared for 16 weeks developed intimal thickening. Conclusion We successfully induced intimal thickening in the carotid arteries of rats with high frequency in the single lesion and tandem lesion groups. The results also showed that the tandem lesion group tended to induce intimal thickening earlier than the single lesion group.

Risk of postoperative scalp necrosis in the occipital artery region after posterior cranial fossa surgery.

Ischemia-induced postoperative scalp necrosis in the superficial temporal artery (STA) region is known to occur after STA-middle cerebral artery anastomoses. However, no reports have evaluated the risk of postoperative scalp necrosis in the occipital artery (OA) region. This study examined the surgical procedures that pose a risk for postoperative scalp necrosis in the OA region following posterior cranial fossa surgery. Patients who underwent initial posterior fossa craniotomy at our institution from 2015 to 2022 were included. Clinical information was collected using medical records. Regarding surgical procedures, we evaluated the incision design and whether a supramuscular scalp flap was prepared. The supramuscular scalp flap was defined as a scalp flap dissected from the sternocleidomastoid and/or splenius capitis muscles. A total of 392 patients were included. Postoperative scalp necrosis occurred in 19 patients (4.8%). There were 296 patients with supramuscular scalp flaps, and supramuscular scalp flaps prepared in all 19 patients with postoperative necrosis. Comparing incision designs among patients with supramuscular scalp flap, a hockey stick-shaped scalp incision caused postoperative necrosis in 14 of 73 patients (19.1%), and the odds of postoperative scalp necrosis were higher with the hockey stick shape than with the retro-auricular C shape (adjusted odds ratio: 12.2, 95% confidence interval: 3.86-38.3, p = 0.00002). In all the cases, ischemia was considered to be the cause of postoperative necrosis. The incidence of postoperative necrosis is particularly high when a hockey stick-shaped scalp incision is combined with a supramuscular scalp flap.

A Patient With Exophytic Primary Optic Nerve Sheath Meningioma: Stratified Risk of Surgery Based on the Morphology.

Primary optic nerve sheath meningioma (pONSM) is one of the most challenging tumors to manage. Although surgical excision may be considered a treatment option to maintain visual function, the safety of surgery remains debatable due to the non-negligible risk of optic nerve injury. pONSM often grows concentrically around the optic nerve; however, it can also demonstrate an exophytic growth from the optic nerve. The risk of surgical excision of pONSM may vary based on the tumor's growth pattern and area of contact with the optic nerve; however, there has been no detailed report on risk stratification to date. The authors present an illustrative case of an exophytic pONSM which was removed surgically without complications, suggesting that tumor morphology may also influence the surgical risk. In this report, the imaging and intraoperative features of exophytic pONSM are presented in detail, and the risk factors for complications are discussed.

Carotid Plaque Diagnosis With 3-Dimensional Computed Tomography Angiography: A Comparison With Magnetic Resonance Imaging-Based Plaque Diagnosis.

OBJECTIVE: Although a qualitative diagnosis of plaque causing carotid stenosis has been attempted with carotid computed tomography angiography (CaCTA), no clear findings have been reported. We examined the correlation between the plaque CT values and plaque images obtained by magnetic resonance imaging to derive a qualitative diagnosis of the plaque using CaCTA. METHODS: Preoperative CaCTA images acquired from patients stented for carotid stenosis were retrospectively analyzed with respect to magnetization-prepared rapid acquisition with gradient echo and time-of-flight magnetic resonance angiography data. Carotid plaques in the stenosed region were quantified in terms of CT density and the plaque/muscle ratio (magnetization-prepared rapid acquisition with gradient echo), and correlations between these 2 features were determined. Plaques were classified as stable or unstable based on the plaque/muscle ratio, with the smallest plaque/muscle ratio observed among plaques positive for intraplaque hemorrhage set as the cutoff value (1.76). RESULTS: A total of 165 patients (179 plaques) were included. Perioperative complications included minor stroke (n = 3), major stroke (n = 1, fatal), and hyperperfusion (n = 2). The correlation between CT density and the plaque/muscle ratio was nonlinear ( P = 0.0139) and negative ( P < 0.0001). The cutoff point (1.76) corresponded to a CT density of 83 HU, supporting this value as a standard reference for plaque stability. CONCLUSIONS: Computed tomography density exhibits a nonlinear ( P = 0.0139) and highly negative correlation ( P < 0.0001) with the plaque/muscle ratio. Our results demonstrate that plaque characteristics can be meaningfully diagnosed based on CaCTA image data.

Anatomical variations and flow alterations of the uncal vein and its clinical implications in petroclival meningiomas.

BACKGROUND: The Uncal vein (UV), downstream of the deep middle cerebral vein (DMCV), has a similar drainage pattern to the superficial middle cerebral vein (SMCV) and may be involved in venous complications during the anterior transpetrosal approach (ATPA). However, in petroclival meningioma (PCM), where the ATPA is frequently used, there are no reports evaluating drainage patterns of the UV and the risk of venous complications associated with the UV during the ATPA. METHODS: Forty-three patients with petroclival meningioma (PCM) and 20 with unruptured intracranial aneurysm (control group) were included. Preoperative digital subtraction angiography was used to evaluate UV and DMCV drainage patterns on the side of the tumor and bilaterally in patients with PCM and the control group, respectively. RESULTS: In the control group, the DMCV drained to the UV, UV and BVR, and BVR in 24 (60.0%), eight (20.0%), and eight (20.0%) hemispheres, respectively. Conversely, the DMCV in the patients with PCM drained to the UV, UV and BVR, and BVR in 12 (27.9%), 19 (44.2%), and 12 (27.9%) patients, respectively. The DMCV was more likely to be drained to the BVR in the PCM group (p < 0.01). In three patients with PCM (7.0%), the DMCV drained only to the UV, and furthermore, the UV drained to the pterygoid plexus via the foramen ovale, posing a risk for venous complications during the ATPA. CONCLUSIONS: In the patients with PCM, the BVR functioned as a collateral venous pathway of the UV. Preoperative evaluation of the UV drainage patterns is recommended to reduce venous complications during the ATPA.

Radiation-induced anterior inferior cerebellar artery pseudoaneurysm after stereotactic radiosurgery for vestibular schwannoma: features observed by direct surgery.

BACKGROUND: In vestibular schwannoma (VS) patients treated with stereotactic radiosurgery (SRS), radiation-induced pseudoaneurysm is a rare long-term complication. To the best of our knowledge, there has been only one report of direct surgery in ruptured cases, and the optimal strategy for direct surgery is yet to be clarified. This case report describes a case of ruptured VS-related SRS-induced pseudoaneurysm that was successfully treated by direct surgery. CASE PRESENTATION: A 57-year -old man underwent SRS for VS, and the tumour was well controlled after the SRS. Nine years after the SRS, however, he developed subarachnoid haemorrhage, and a SRS-induced distal anterior inferior cerebellar artery aneurysm was detected on the surface of the tumour. During the trapping surgery, the aneurysm was embedded in the tumour, and it was difficult to separate the aneurysm and tumour. Besides, the facial nerve and tumour restricted exposure of the parent artery. The parent artery proximal to the aneurysm could only be exposed by resecting caudal part of the tumour. The aneurysm was trapped with permanent clips and it was pathologically diagnosed as pseudoaneurysm. CONCLUSION: It was suggested that the VS-related SRS-induced pseudoaneurysm is tightly adhered with surrounding structures and exposure of the parent artery could be limited due to the tumour and facial nerve. In this case report, we describe detailed intraoperative findings that will be useful for developing strategies for trapping surgery in future.

Relationship between epicardial adipose tissue and coronary artery stenoses on computed tomography in patients scheduled for carotid artery revascularization.

BACKGROUND: We aimed to clarify the relationship between epicardial adipose tissue (EAT) volume and the presence of severe stenoses (SS) on coronary computed tomography angiography (CTA) for risk stratification of the patients with carotid artery stenoses. METHODS: We prospectively performed CTA for 125 consecutive patients (72.4 ± 8.1 years, 85% men) without a history of coronary artery disease (CAD), who were scheduled for carotid artery revascularization from 2014 to 2020. SS was defined as ≥70% luminal stenosis on CTA. EAT was quantified automatically as the total volume of tissue with -190 to -30 HU. RESULTS: Of 125 patients, 76 had SS. Between the patients with and without SS, there were significant differences in coronary artery calcium score (CACS), left ventricular ejection fraction (LVEF), dyslipidemia, and EAT, despite no differences in carotid echocardiography findings. After adjustment for age, gender, and dyslipidemia, EAT was an independent factor associated with SS (p=0.011), as well as CACS and LVEF. The addition of EAT to a baseline model including age, gender, dyslipidemia, LVEF, and CACS achieved both net reclassification improvement (0.505, p=0.003) and integrated discrimination improvement (0.059, p=0.003). CONCLUSIONS: In patients with carotid stenoses, EAT is associated with CAD and is useful for additional risk stratification. Epicardial fat may have a specific role in the development of CAD in patients with suspected systemic atherosclerosis.

Coexistence of RASA1 and COL4A2 variants caused pial arteriovenous fistula (AVF) in a patient with capillary malformation-arteriovenous malformation.

Pial arteriovenous fistulas (AVFs) are rare vascular lesions; their exact pathophysiology is largely unknown. Pial AVFs have been reported to develop within capillary malformation-arteriovenous malformation (CM-AVM); however, only a few cases have been reported. Variants in the RASA1 gene have been reported as a cause of CM-AVM. We report the case of an adult patient with pial AVF, who carried variants in the RASA1 and COL4A2 genes. The patient in the current report was likely to have been affected by CM-AVM and the RASA1 variant seemed to be the primary factor in the pathogenesis of pial AVF. However, COL4A2 may have also contributed to the development of pial AVF because the COL4A2 and RASA1 variants have a common pathophysiology, wherein the patient develops lesions due to collagen type IV deficiency.

Reduction of thromboembolic complications during the endovascular treatment of unruptured aneurysms by employing a tailored dual antiplatelet regimen using aspirin and prasugrel.

BACKGROUND: Thromboembolic complications (TECs) are frequent during the endovascular treatment of unruptured aneurysms. To prevent TECs, dual antiplatelet therapy using aspirin and clopidogrel is recommended for the perioperative period. In patients with a poor response, clopidogrel is a risk factor for TECs. To prevent TECs, our study assessed the stratified use of prasugrel. METHODS: Patients who underwent endovascular therapy for unruptured cerebral aneurysms from April 2017 to August 2019 were enrolled in this clinical study and given premedication with aspirin and clopidogrel for 2 weeks prior to the procedure. P2Y12 reaction units (PRU) were measured using the VerifyNow assay on the day before the procedure (tailored group). In subgroups with PRU <240, the clopidogrel dose was maintained (CPG subgroup). In subgroups with PRU ≥240, clopidogrel was changed to prasugrel (PSG subgroup). We compared the occurrence of TECs with retrospective consecutive cases from January 2015 to March 2017 without PRU assessments (non-tailored group). The frequency of TECs within 30 days was assessed as the primary endpoint. RESULTS: The tailored and non-tailored groups comprised 167 and 50 patients, respectively. TECs occurred in 11 (6.6%) and 8 (16%) patients in the tailored and non-tailored groups (P=0.048), respectively. The HR for TECs was significantly reduced in the tailored group (HR 0.3, 95% CI 0.11 to 0.81); P=0.017) compared with the non-tailored group. CONCLUSION: The results suggest that tailored dual antiplatelet therapy medication with PRU significantly reduces the frequency of TECs without increasing hemorrhagic complications.

Relationship between the Volume Rate of Ed Coil (Ed Ratio) and Packing Density in Endosaccular Embolization of Cerebral Aneurysms.

PURPOSE: A high packing density (PD) (i.e., coil volume per aneurysm volume) helps prevent recanalization after endosaccular embolization of cerebral aneurysms. We hypothesized that the use of soft coils may be useful to raise PD and retrospectively investigated the correlation between the ED coil volume rate (i.e., volume ratio of all placed coils) and PD in patients treated with endosaccular embolization using this coil. METHODS: Excluding aneurysms treated with a stent, 292 aneurysms treated using ED coils were included in this study. The 292 aneurysms and aneurysms with ≥30%, ≥40%, and ≥50% ED coil volume rates (202, 168, and 129 aneurysms, respectively) underwent linear regression analysis of the following seven factors' influence on PD:ED ratio, aneurysm volume, neck width, height, maximum diameter, dome-to-neck ratio, and aspect ratio. RESULTS: Independent factors of a high PD were high ED ratio and small neck width on analyses of aneurysms with an ED ratio of ≥40% and ≥50%. Only neck width was an independent factor on analyses of all 292 aneurysms and aneurysms with ED ratio of ≥30%. CONCLUSION: The use of ED coils in high volume rate correlated with a high PD and may contribute to prevent recanalization in small aneurysms.

Use of Detachable Coils Without the Need of a Double Marker Microcatheter: Technical Note.

When using detachable coils for cerebral aneurysm embolization, it is necessary to place a microcatheter with radiopaque markers at 2 sites (tip and 3 cm proximal from the tip) in most cases. Detachable coils that can be positioned independently from the proximal marker may facilitate new applications utilizing their characteristics. Herein, we report 2 cases that were treated with new applications. Detachable coils that function to electrically detect the moment they come out of the microcatheter were used. In one patient with a large aneurysm with an irregular shape, coil embolization was applied by advancing the catheter more than 3 cm from the aneurysm neck to the caudally protruded compartment near the proximal end of the neck, which was difficult to reach with the coil. In the other patient with cerebral arteriovenous malformation (AVM), microcatheters for AVM without a proximal marker were used for coil embolization before Onyx injection: Coil embolization was applied through one microcatheter to a site more proximal than the tip of the other microcatheter, followed by Onyx injection through the distal catheter, by which the nidus was continuously penetrated from the initiation of injection, obtaining an effect similar to that of the plug and push technique. Through the use of detachable coils, which are not dependent on the visibility of the proximal marker, the limitation of catheter positioning is reduced and the applicable types of catheter increase, which may facilitate to enable its use for new clinical indications.

Noninvasive Assessment of Stenotic Severity and Plaque Characteristics by Coronary CT Angiography in Patients Scheduled for Carotid Artery Revascularization.

AIMS: Coronary artery atherosclerosis in patients needing carotid revascularization has not been fully clarified. The aim of this study was to evaluate the stenotic severity and plaque characteristics of coronary arteries by coronary computed tomography angiography (CTA) in patients scheduled for carotid-artery stenting (CAS) or carotid endarterectomy (CEA). METHODS: We performed coronary CTA after carotid ultrasound (US) in 164 patients (81.7% male, aged 68.1± 12.2 years) from 2014 to 2016. Of all, 70 were scheduled for CAS or CEA (CAS/CEA group) and 94 were not (non-CAS/CEA group). Carotid US and coronary CTA were compared for the evaluation of stenotic severity and plaque characteristics of each vessel between CAS/CEA and non-CAS/CEA groups. RESULTS: Between the two groups, there were significant differences in the presence of significant stenosis (SS: ≥70% stenosis of coronary artery) (55.7% vs. 39.4%, P=0.038), triple-vessel disease (TVD)/left main trunk (LMT) (SS in each of three epicardial vessels and/or LMT) (24.3% vs. 7.5%, P= 0.0025), and high-risk plaque (HRP: positive remodeling and/or low attenuation) (55.7% vs. 24.5%, P＜0.0001). CAS/CEA was independently associated with TVD/LMT (OR=2.30, 95%CI: 1.14-8.59, P=0.026) and HRP (OR=3.17, 95%CI: 1.57-6.54, P=0.0012) in multivariable logistic regression analysis. Similarly, vulnerable plaque (78.6% vs. 2.1%, P＜0.0001) as well as severe stenosis of carotid artery (98.6% vs. 0%, P＜0.0001) was seen more often in CAS/CEA than in non-CAS/CEA group. CONCLUSIONS: The prevalence of TVD/LMT and HRP determined by coronary CTA is higher in patients needing CAS/CEA than in those without. Management of systemic atherosclerosis is required in the perioperative period of CAS/CEA.

Carotid stenting for unilateral stenosis can increase contralateral hemispheric cerebral blood flow.

BACKGROUND: The revascularization of carotid stenosis can increase ipsilateral cerebral blood flow (CBF). Occasionally, elevated CBF is also evident on the contralateral side, but this phenomenon is poorly understood. OBJECTIVE: To analyze retrospectively the relationship between a contralateral CBF increase and several clinical and radiologic features. MATERIALS AND METHODS: We retrospectively analyzed 40 patients with unilateral cervical carotid stenosis treated by carotid artery stenting (CAS). Using 123I-iodamphetamine single-photon emission computed tomography (SPECT); we compared pre- and postoperative hemispheric CBF on both sides. We investigated the influence of the following five factors on the increase of the contralateral hemispheric CBF: stenosis grade (≥50% or <50%, according to the North American Symptomatic Carotid Endarterectomy Trial criteria); age; the presence of anterior and posterior communicating arteries; postoperative hyperperfusion on the stenotic side; and the presence of cerebral steal phenomenon during preoperative acetazolamide-challenge SPECT. RESULTS: Following unilateral CAS, mean hemispheric CBF increased significantly on both sides: from 33.4±5.6 (mean ± SD) to 38.7±7.8 mL/min on the operated side (paired t test, p<0.001) and f35.4±5.4 to 39.2±7.2 mL/min on the contralateral side (p<0.001). In a general linear model, stenosis grade (≥50%) alone was significantly correlated with the increase of the CBF on the contralateral side (p=0.03). CONCLUSION: Revascularization by CAS for unilateral carotid stenosis can increase hemispheric CBF on both sides. Increase of the contralateral CBF is correlated with stenosis grade (≥50%).

Intraoperative Anatomical and Hemodynamic Analysis of Intracerebral Arteriovenous Malformations by Semi-quantitative Color-coded Indocyanine Green Videoangiography.

OBJECTIVE AND BACKGROUND: To evaluate possible roles for indocyanine green (ICG)-based FLOW 800 software in surgical treatment of cerebral arteriovenous malformations (AVMs). METHODS: We perform ICG videoangiography several times for each step of AVM resection to elucidate feeders, drainers, and cerebral perfusion. RESULTS: Since 2010, 22 AVM surgeries in our department have been conducted using FLOW 800 intraoperatively. We demonstrated ICG angiograms, color-coded images, and semi-quantitative curves for AVMs. By reviewing all these modalities, we would define vascular structure of the AVM, proceed with resection, and finally recheck for any remnant. CONCLUSIONS: ICG FLOW 800 software helps the surgeon to recognize feeding and draining vessels of an AVM intraoperatively. Further studies to evaluate semi-quantitative acquired data regarding blood flow and tissue perfusion are warranted.

Predictive Value of Motor Evoked Potential Monitoring during Surgery of Unruptured Anterior Circulation Cerebral Aneurysms.

OBJECTIVE AND BACKGROUND: Surgery of unruptured aneurysms is always a great challenge to neurovascular surgeons because no postoperative neurological deficits should be expected postoperatively as the patients are fully asymptomatic before the surgery. Here, we present our experience with selective motor evoked potential (MEP) monitoring of our patients in a 2-year time window. PATIENTS AND METHODS: From 2012 to 2014, 27 patients with unruptured intracranial aneurysms were operated in our institute with the help of MEP monitoring. All patients underwent endoscope-assisted microsurgery with pre- and post-clipping indocyanine green angiography. RESULTS: In this period, no mortality was observed, but 18.5% of the patients developed postoperative deficits which showed good recovery in all cases. Overall, MEP showed about 90% accuracy in predicting postoperative deficits. CONCLUSIONS: MEP as a part of multimodality monitoring of aneurysm surgeries is a valuable tool to improve the outcome. However, we should know its limitations as its results are not always consistent with the outcome.

Acute carotid artery stenting in symptomatic high-grade cervical carotid artery stenosis.

The safety and efficacy of emergency carotid artery stenting (CAS) for patients with acute ischemic stroke resulting from internal carotid artery stenosis are not established. In this retrospective study, we evaluated outcomes for CAS performed within 2 weeks of acute ischemic stroke for 16 patients treated between December 2009 and February 2014. Cases of internal carotid artery occlusion, internal carotid dissection, or intracranial major arterial trunk occlusion were excluded. Five patients were treated with CAS during the hyperacute phase (within 24 h of stroke onset), three in the advanced phase (within 24 h of stroke-in-evolution after admission), and eight in the acute phase (24 h to 2 weeks after onset). We evaluated modified Rankin scale (mRS) scores 90 days after CAS. For patients treated during the hyperacute phase without intravenous tissue-type plasminogen activator (IV-tPA), two had mRS scores of 2 and one had a score of 3. Two patients treated in the hyperacute phase with IV-tPA had scores of 5: one with symptomatic intracerebral hemorrhage and the other with acute brain swelling. For patients treated in the advanced phase, mRS scores were 1, 3, and 5; the patient with 5 had contralateral cerebral infarction. All patients treated in the acute phase had scores of 2 or lower. Patients treated with IV-tPA in advanced or acute phases had no severe post-CAS complications. CAS was effective and safe for treating ischemic stroke within 2 weeks of onset. However, IV-tPA treatment may be a risk factor for CAS treatment during the hyperacute phase.

Large Residual Volume, Not Low Packing Density, Is the Most Influential Risk Factor for Recanalization after Coil Embolization of Cerebral Aneurysms.

BACKGROUND: Tight coil packing with density of at least 20%-25% is known to be important for preventing recanalization after embolization of cerebral aneurysms. However, large aneurysms sometimes recanalize regardless of the packing density, suggesting that the absolute residual volume which is determined by aneurysm volume and packing density may be more important risk factor for recanalization. To validate this hypothesis, we analyzed the factors affecting the outcomes of treated aneurysms at our institute. METHODS AND FINDINGS: We included 355 small and large aneurysms. The following six factors were obtained from every case: aneurysm volume (mL), neck size (mm), packing density (%), residual volume (mL), rupture status at presentation, and stent assistance (with or without stent). The data were then subjected to multivariate logistic regression analysis to identify significant risk factors for recanalization. Recanalization occurred in 61 aneurysms (17.2%). Significant predictors for recanalization were aneurysm volume (odds ratio, 15.3; P < 0.001) and residual volume (odds ratio, 30.9; P < 0.001), but not packing density (odds ratio, 0.98; P = 0.341). These results showed that for each 0.1-mL increase in aneurysm volume and residual volume, the risk of recanalization increased by 1.3 times and 1.4 times, respectively. CONCLUSIONS: The most influential risk factor for recanalization after coil embolization was residual volume, not packing density. The larger the aneurysm volume, the greater the packing density has to be to minimize the residual volume and risk of recanalization. Since tight coil packing has already been aimed, further innovation of coil property or embolization technique may be needed. Otherwise, different treatment modality such as flow diverter or parent artery occlusion may have to be considered.

Concurrence of Aneurysmal Subarachnoid Hemorrhage and Stanford Type A Acute Aortic Dissection.

We report a rare case of concurrent aneurysmal subarachnoid hemorrhage (SAH) and acute aortic dissection (AAD). A 38-year-old man visited our hospital complaining of severe headache, and brain computed tomography (CT) revealed the presence of SAH. Thoracic to neck computed tomography angiography (CTA), performed in addition to brain CTA, suggested a tear in the aortic arch, and subsequent CT aortography established the diagnosis of Stanford type A AAD. The AAD in our patient, who reported no episodes of chest or back pain, was detected incidentally by thoracic to neck CTA. The imaging study has rarely been indicated for SAH except that it provides additional anatomical information in patients for whom extracranial-intracranial bypass surgery or endovascular treatment is considered. Nevertheless, our experience may highlight additional diagnostic value of thoracic to neck CTA in SAH patients.

Improvement in patient outcomes following endovascular treatment of WFNS grade V subarachnoid haemorrhage from 2000 to 2014.

Patient outcomes following grade V subarachnoid haemorrhage (SAH) have been dismal, although they may have improved following recent technological advances in endovascular treatment (EVT). A single-centre, retrospective study was conducted to evaluate whether outcomes have improved from 2000 to 2014 for patients with World Federation of Neurosurgical Societies (WFNS) grade V SAH. Coiling has been the preferred first-line treatment for grade V SAH patients in our institution since 2000. Patients who underwent EVT (n=115) were grouped on the basis of their hospital admission year: 2000-2004 (n=44), 2005-2009 (n=37) and 2010-2014 (n=34). Patient demographics, outcomes and in-hospital mortality rates were compared between the groups. Patient outcomes at discharge were evaluated using the Glasgow Outcome Scale (GOS), with GOS scores of 4-5 defined as favourable outcomes. There were no significant intergroup differences in patient demographics. In addition, there were no significant differences in the frequencies of favourable outcomes (14% in 2000-2004, 16% in 2005-2009 and 26% in 2010-2014). Mortality rates were 52% in 2000-2004, 43% in 2005-2009 and 24% in 2010-2014, with a significantly lower mortality rate in 2010-2014 than in 2000-2004 (p=0.01). Both perioperative rebleeding and delayed cerebral ischaemia decreased over time; however, multivariate regression analysis showed that the former contributed more to the decrease in mortality. Age was the only variable associated with favourable outcomes. The results of this study indicate that EVT is an appropriate therapeutic option for grade V SAH patients. However, multi-centre, prospective trials are required to provide evidence-based verification of the efficacy of EVT.

Modified Balloon Protection Technique for Preoperative Embolization of Feeder Arteries from Internal Carotid Artery Branches to Skull-Base Tumor: Technical Note.

OBJECTIVE: To improve bleeding management during brain tumor surgery, feeder arteries supplying the tumor are often embolized presurgically. However, access to feeder arteries can be limited, and embolization of feeders from internal carotid artery (ICA) branches often causes complications. We evaluated the PercuSurge GuardWire (Medtronic, Minneapolis, Minnesota, United States) system (PGWS) with aspiration catheter as a modification of the embolization technique used to block tumor-supplying branches of the ICA. METHODS: Two skull-base tumors were treated with preoperative embolization. One was a meningioma; the other was a hemangiopericytoma. In each case, the microcatheter could not be threaded into the ICA feeder arteries. Therefore, particulate embolic material was injected near the ICA branch while maintaining ICA balloon protection by the PGWS at the orifice of the ophthalmic artery. After embolization, we removed the remaining embolic material in the ICA using an aspiration catheter. In both cases, there were no postembolization complications and no high-intensity areas in the diffusion-weighted magnetic resonance image, and the tumorectomy proceeded as scheduled. CONCLUSION: This modified technique may be a promising alternative for reducing embolic complications and improving the success rate, although case accumulation is needed to confirm this result.