Retrograde stenting through anterior communicating artery in coil embolization of the posterior communicating artery aneurysm: contralateral approach.

During coil embolization of wide-necked posterior communicating artery (PcomA) aneurysms, stent assistance is sometimes limited if PcomA is acutely angled at its origins from saccular neck. Herein, we present two instances where retrograde stenting was used for coil embolization of PcomA aneurysms. Both procedures involved a contralateral approach via anterior communicating artery (AcomA). To achieve this, the stent-delivery microcatheter was inserted retrograde from contralateral to ipsilateral internal carotid artery (ICA) across AcomA, arriving at ipsilateral PcomA. A separate microcatheter, passed through ipsilateral ICA, was then used to select the aneurysm sac for coil delivery. Coil embolization ultimately took place under protection of a horizontally placed stent extending from PcomA to terminal ICA. Each aneurysm was properly coiled and occluded, without procedural complications. This stenting technique is a reasonable option, offering a means of strategic coil embolization in wide-necked PcomA aneurysms and providing complete neck coverage through contralateral access.

Endovascular management of multiple intracranial dural arteriovenous fistulas.

BACKGROUND AND PURPOSE: Multiply occurring intracranial dural arteriovenous fistulas (dAVFs) have been documented but rarely occur, and neither pathogenesis nor prognosis is clearly understood. This study was conducted to analyze angiographic characteristics of multiple dAVFs and to chronicle our treatment experience. METHODS: Between April, 2002 and January, 2018, data prospectively collected from 310 patients with intracranial dAVFs were systematically reviewed, assessing clinical and anatomic outcomes of endovascular treatment in 32 patients with multiple dAVFs (≥ 2 fistulas each). Lesions were categorized as multifocal or diffuse type, depending on presentation, and further characterized as progressive or non-progressive disease. RESULTS: Overall, 18 patients (56.3%) experienced aggressive presentations, including intracerebral hemorrhage or venous infarction. Cortical venous reflux (CVR) was observed in 26 patients (81.3%), and sinus thrombosis or occlusion was seen in 24 (75.0%). Clinical outcomes in patients with multifocal fistulas (n = 11) were excellent (100%), marked by a moderately high rate of complete occlusion (54.5%). Those with progressive disease (n = 10) regularly displayed certain angiographic findings, namely diffuse configuration (100%), sinus thrombosis (100%), and CVR (100%). Complete anatomic obliteration was achieved in 12 patients (37.5%), and in 26 patients (81.3%), clinical outcomes were favorable. CONCLUSION: Multiple dAVFs are typically aggressive at presentation, given strong associations with CVR and sinus thrombosis. In diffuse-type fistulas, the potential to recur or progress is high. Although definitive treatment poses a challenge, outcomes of endovascular therapeutics may be still optimized in this setting through strategic procedural modifications and careful follow-up monitoring.

Monitoring Cerebral Perfusion Changes after Revascularization in Patients with Moyamoya Disease by Using Arterial Spin-labeling MR Imaging.

Purpose To determine whether arterial spin-labeling (ASL) magnetic resonance (MR) imaging could be used to identify changes in cerebral blood flow (CBF), collateral blood flow, and anastomosis site patency after revascularization in patients with moyamoya disease. Materials and Methods This retrospective study was conducted in 145 patients with moyamoya disease who underwent middle cerebral artery (MCA)-superficial temporal artery anastomosis. Preoperative, early postoperative, and late postoperative ASL and digital subtraction angiography images were analyzed. In the MCA territory, absolute CBF (hereafter, CBFMCA) and normalized CBF values adjusted to nonanastomosis side (hereafter, nCBFMCA) and to cerebellum (hereafter, nCBFCbll) were calculated. Collateral grading in the MCA territory was assessed according to Alberta Stroke Program Early CT Score methodology, and anastomosis site patency were also assessed. Changes in CBF were compared by using one-way analysis of variance with Bonferroni correction for multiple comparisons. Intermodality agreement was determined by κ statistics. Results Significant increases in CBFMCA, nCBFMCA, and nCBFCbll were found after revascularization (preoperative and postoperative values of CBFMCA, 35.2 mL/100 g per minute ± 7.8 [mean ± standard deviation] and 51.5 mL/100 g per minute ± 12.0; nCBFMCA, 0.73 mL/100 g per minute ± 0.14 and 1.01 mL/100 g per minute ± 0.18; nCBFCbll, 0.74 mL/100 g per minute ± 0.12 and 1.12 mL/100 g per minute ± 0.16; all P < .001). Agreements for collateral grading and anastomosis patency between ASL MR imaging and digital subtraction angiography were moderate to good, with weighted κ values of 0.77 (95% confidence interval: 0.73, 0.81) and 0.57 (95% confidence interval: 0.37, 0.76), respectively. Conclusion ASL MR imaging can be used to identify perfusion changes in patients with moyamoya disease after revascularization as a noninvasive monitoring tool.

Correction to: Does stent type impact coil embolization outcomes in extended follow-up of small-sized aneurysms (< 10 mm)?

The original version of this article contained a mistake in Fig. 4: Fig. 4a and d were interchanged. The correct figure is shown below. The original article has been corrected.

Does stent type impact coil embolization outcomes in extended follow-up of small-sized aneurysms (< 10 mm)?

PURPOSE: Self-expandable stents have enabled endovascular treatment of wide-necked aneurysms (ordinarily viewed as technically prohibitive), with favorable outcomes. However, the impact of stent type on occlusive stability has not been adequately investigated. In small-sized unruptured saccular aneurysms, we generated estimates of stent-assisted coil embolization outcomes during follow-up monitoring. Stent type and other risk factors linked to recanalization were analyzed. METHODS: A cohort of 286 patients harboring 312 small-sized unruptured aneurysms (< 10 mm) was subjected to mid-term and extended follow-up monitoring after stent-assisted coiling. Three types of stents (Enterprise, 192; Neuroform, 27; LVIS, 93) were deployed in this population; all medical records and radiologic data of which were reviewed. Mid-term recanalization rates and related risk factors were assessed using binary logistic regression analysis. RESULTS: A total of 49 aneurysms (15.7%) displayed recanalization at 6 months postembolization, with 34 and 15 instances of minor and major recanalization, respectively. Multivariate analysis indicated that wide-necked aneurysms (> 4 mm) (HR = 2.362; p = 0.017), incomplete occlusion at time of coiling (HR = 2.949; p = 0.002), and stent type (p = 0.048) were significant factors in mid-term recanalization, whereas hypertension (p = 0.095) and packing density ≤ 30% (p = 0.213) fell short of statistical significance. Compared with Enterprise (HR = 2.828) or Neuroform (HR = 4.206) stents, outcomes proved more favorable with use of LVIS. CONCLUSIONS: Above findings demonstrate that in addition to occlusive status at time of coil embolization and neck size, stent type may affect follow-up outcomes of stent-assisted coil embolization in small-sized aneurysms. LVIS (vs Enterprise or Neuroform stents) performed best during follow-up monitoring in terms of limiting recanalization.

Monitoring Cerebrovascular Reactivity through the Use of Arterial Spin Labeling in Patients with Moyamoya Disease.

PURPOSE: To assess arterial spin labeling in the identification of impaired cerebrovascular reactivity in patients with moyamoya disease. MATERIALS AND METHODS: The institutional review board approved this prospective study, and written informed consent was obtained from all patients. A prospective study was conducted in 78 subjects with moyamoya disease (of whom 31 underwent unilateral direct arterial anastomosis). The concordance between the cerebrovascular reactivity index values from arterial spin labeling and single photon emission computed tomography (SPECT) was assessed by using Bland-Altman analysis, and the area under the receiver operating characteristic curve was used to evaluate the diagnostic accuracy of arterial spin labeling to depict impaired cerebrovascular reactivity (in which the cerebrovascular reactivity index value is less than 0% on SPECT images). RESULTS: The cerebrovascular reactivity index from arterial spin labeling had a lower value than that from SPECT (mean difference, -4.2%). The area under the receiver operating characteristic curve for arterial spin labeling in the detection of impaired cerebrovascular reactivity was at least 0.85. On the anastomotic side, a significant increase was found between the cerebrovascular reactivity index values on arterial spin labeling images obtained preoperatively and those obtained 6 months after surgery, as well as on SPECT images (mean ± standard deviation values of cerebrovascular reactivity index increased by 5.9% ± 10.9 and 3.0% ± 6.3 for arterial spin labeling and SPECT, respectively). CONCLUSION: Arterial spin labeling has excellent performance in the identification of impaired cerebrovascular reactivity in patients with moyamoya disease, and it has the potential to serve as a noninvasive imaging tool to monitor cerebrovascular reactivity in patients with moyamoya disease.

Intra-arterial thrombolysis of central retinal artery occlusion following percutaneous atrial septal defect closure.

Use of percutaneous devices for atrial septal defect (ASD) closure is growing, given the minimally invasive nature and the long-term durability of this approach. The reported rate of thrombus formation after catheter closure is 1.2%. Thrombotic risk varies according to closure device and Dacron-covered nitinol Amplatzer devices carry a 0-0.3% rate of thrombus formation; but central retinal artery occlusion (CRAO) is rarely implicated as an adverse event. Herein, we report the first successful intra-arterial thrombolytic treatment of CRAO developing after ASD closure via Amplatzer device. © 2015 Wiley Periodicals, Inc.

Extended monitoring of coiled aneurysms completely occluded at 6-month follow-up: late recanalization rate and related risk factors.

OBJECTIVES: To estimate long-term durability in coiled aneurysms completely occluded at 6-month follow-up imaging, focusing on late recanalization rate and the risk factors involved. METHODS: A cohort of 620 patients harbouring 698 completely occluded coiled aneurysms at 6-month follow-up was subjected to extended monitoring (mean, 24.5 ± 7.9 months). Cumulative recanalization rate and related risk factors were analysed using Cox proportional hazards regression and Kaplan-Meier product-limit estimator. RESULTS: Forty-three aneurysms (6.2 %) occluded completely at 6-months displayed recanalization (3.02 % per aneurysm-year) during continued surveillance (1425.5 aneurysm-years), with 26 (60.5 %) surfacing in another 6 months, 15 (34.9 %) within 18 months and 2 (4.6 %) within 30 months. Cumulative survival rates without recanalization were significantly lower in subjects with aneurysms >7 mm (p = 0.014), with bifurcation aneurysms (p = 0.009) and with subarachnoid haemorrhage (SAH) at presentation (p < 0.001). Multivariate analysis indicated that aneurysms >7 mm (HR = 2.37, p = 0.02) and bifurcation aneurysms (HR = 2.70, p = 0.03) were significant factors in late recanalization, whereas a link with SAH at presentation was marginal (HR = 1.92, p = 0.06) and stent placement fell short of statistical significance (HR = 0.47; p = 0.12). CONCLUSION: Most (93.8 %) coiled aneurysms showing complete occlusion at 6 months post-procedure were stable in long-term monitoring. However, aneurysms >7 mm and bifurcation aneurysms were predisposed to late recanalization. KEY POINTS: • Most coiled aneurysms showing complete occlusion at 6 months were stable. • Forty-three aneurysms (6.2 %) occluded completely at 6-month follow-up displayed late recanalization. • Late recanalization rate was 3.02 % per aneurysm-year during follow-up of 1425.5 aneurysm-years. • Aneurysms over 7 mm and bifurcation aneurysms were predisposed to late recanalization.

Pediatric spinal arteriovenous malformations and fistulas: a single institute's experience.

OBJECTIVE: Pediatric spinal vascular diseases are extremely rare. We aimed to evaluate their clinical characteristics and treatment outcomes in our institute. DESIGN: A total of 10 patient files were retrospectively reviewed, including 3 cases of intramedullary arteriovenous malformations (AVMs), 6 cases of perimedullary arteriovenous fistulas (AVFs), and 1 case of epidural AVF. Clinical features, radiological findings, treatment results, and clinical outcomes were evaluated. The median durations of the radiologic and clinical follow-ups were 17.7 and 107.9 months, respectively. RESULTS: The male to female ratio was 1:1, with a median age at diagnosis of 9 years. All AVMs were juvenile type, all perimedullary AVFs were high flow types (three type IVb and three type IVc), and one epidural AVF was associated with intradural venous drainage. Most cases (90 %) were located in the cervical spine and conus medullaris. Acute neurological deterioration was identified in five patients; however, bleeding was identified in only one patient. Two cases were surgically treated, seven cases underwent embolization, and one case underwent radiosurgery. Three cases were completely obliterated, and their clinical states were improved (n = 2; 66.7 %) and stationary (n = 1; 33.3 %). Meanwhile, seven cases were incompletely obliterated, and their clinical states were improved (n = 2; 28.6 %), stationary (n = 3; 42.8 %), and aggravated (n = 2; 28.6 %). CONCLUSIONS: Pediatric spinal AVMs and AVFs were mostly complex and high flow types, and complete obliteration could not be satisfactorily achieved. Incompletely treated lesions should be closely followed up because they may worsen.

Bright vessel appearance on arterial spin labeling MRI for localizing arterial occlusion in acute ischemic stroke.

BACKGROUND AND PURPOSE: The purpose of this study was to evaluate whether bright vessel appearance on arterial spin labeling (ASL) MRI can help localize arterial occlusion sites in patients with acute ischemic stroke. METHODS: Patients who underwent MRI for suspected acute ischemic stroke, as identified by an area of restricted diffusion, were included. All images were visually analyzed for the presence or absence of (1) arterial occlusion on time-of-flight MR angiography, (2) bright vessel appearance on ASL images, and (3) susceptibility vessel sign. McNemar 2-tailed test was used to compare the sensitivities of ASL and susceptibility-weighted imaging for the detection of arterial occlusion, using MR angiography as the reference standard. RESULTS: ASL bright vessel appearance was significantly more common in the group with occlusion than in the group without occlusion (94% [33 of 35] versus 21% [17 of 82], respectively; P<0.001). The bright vessel appearance, when present, was seen proximal or distal to the occlusion site. The bright vessel appearance had a significantly higher sensitivity for the detection of occlusion than the susceptibility vessel sign (94% [33 of 35] versus 66% [23 of 35], respectively; P=0.002). In cases with negative MR angiography, the bright vessel appearance helped identify more additional arterial occlusions than the susceptibility vessel sign (21% [17 of 82] versus 10% [8 of 82], respectively; P=0.012). CONCLUSIONS: The bright vessel appearance on ASL imaging can provide an important diagnostic clue for the detection and localization of arterial occlusion sites in patients with acute ischemic stroke.

Polymeric embolization coil of bilayered polyvinyl alcohol strand for therapeutic vascular occlusion: a feasibility study in canine experimental vascular models.

PURPOSE: To investigate the feasibility of polyvinyl alcohol (PVA) polymer coil as a new endovascular embolic agent and to gauge the related histologic response in a canine vascular model. MATERIALS AND METHODS: PVA polymer coil was fabricated by cross-linking PVA and tantalum particles. Basic properties were then studied in vitro via swelling ratio and bending diameter. Normal renal segmental arteries and wide-necked aneurysms of carotid sidewalls served as canine vascular models. Endovascular PVA coil embolization of normal renal segmental arteries (N = 20) and carotid aneurysms (N = 8) was performed under fluoroscopic guidance in 10 dogs. Degree of occlusion was assessed immediately and at 4 weeks after embolization by conventional and computed tomographic angiography. Histologic features were also graded at acute (day 1, six segmental arteries and four aneurysms) and chronic phases (week 4, 14 segmental arteries and four aneurysms) after embolization to assess inflammation, organization of thrombus, and neointimal proliferation. RESULTS: Swelling ratio declined as concentrations of cross-linking agent increased. Mean bending diameters were 2.05 mm (range, 0.86-6.25 mm) in water at 37 °C and 2.29 mm (range, 0.94-6.38 mm) in canine blood samples at 37 °C. Occlusion of normal renal segmental arteries was sustained (complete occlusion at day 1, n = 20; at week 4, n = 14), whereas immediate outcomes in carotid aneurysms (day 1, complete occlusion, n = 5; residual neck only, n = 3) were not sustained (week 4, complete occlusion, n = 1; minor recanalization, n = 1; major recanalization, n = 2). At week 4, chronic inflammatory cells predominated, with progressive organization of thrombus and fibrocellular ingrowth. All aneurysms bore full neointimal linings on the coil mass in the chronic phase. CONCLUSIONS: Vascular occlusion by PVA polymer coil proved superior in normal renal segmental arteries and feasible in surgically constructed carotid aneurysms (with packing densities ≥ 30%), constituting acceptable radiologic feasibility and histologic response.

Modified coil protection for proper coil frame configuration in wide-necked aneurysms.

INTRODUCTION: Although various protective techniques for treating wide-necked intracranial aneurysms currently exist and continue to evolve, their utility may be limited in some lesions with complex configurations, small-caliber channels, or inherently tortuous vascular patterns. Described herein is a modified coil protection technique as a novel adjunct for proper coil frame configuration. METHODS: Initially, a microcatheter is passed into aneurysmal sac, and the first coil is inserted to build a frame. Inevitably, some coils may abut opposite poles of aneurysms and protrude into parent arteries. Should this happen, a second microcatheter may be placed at the site of coil protrusion, so that a separate and smaller coil may be partially deployed for protection. A framing coil may then be configured within aneurysmal sac, under protection of the secondary coil. Once the first coil is entirely in place, the remainder of second coil is carefully inserted, and additional coil may be inserted as needed via dual microcatheters. RESULTS: This technique was successfully applied to 23 saccular intracranial aneurysms of internal carotid (n = 8), middle cerebral (n = 6), anterior cerebral (n = 6), and superior cerebellar artery (n = 3), combining stent protection in two patients and balloon remodeling in one. Selective endovascular treatment was effective as a result. Excellent outcomes were achieved in all patients, with no morbidity or mortality directly related to the modified procedure. CONCLUSION: As suggested by outcomes of this small study, our modified coil protection method may be a safe option if traditional coiling strategies are not feasible, enabling stable coil frame configuration in wide-necked aneurysms.

Progressive thrombosis of small saccular aneurysms filled with contrast immediately after coil embolization: analysis of related factors and long-term follow-up.

INTRODUCTION: Although it is well-known that incomplete occlusion of aneurysms after coil embolization predisposes to later recanalization, not all aneurysms will be fully occluded by coiling. In follow-up, we evaluated outcomes of small aneurysms (<10 mm) that showed filling of the sac with contrast immediately after coil embolization and assessed factors implicated in subsequent progressive thrombosis. METHODS: Between January 2008 and December 2010, a total of 1035 aneurysms in 898 patients were treated by endovascular coiling. Of these, 210 small aneurysms displayed filling of the sac by contrast immediately after coil embolization. Time-of-flight magnetic resonance angiography (TOF-MRA; at 6, 12, 24, and 36 months) and digital subtraction angiography (as needed) were used for postoperative monitoring. Complete occlusion of these aneurysms at the 6-month follow-up point was attributed to progressive thrombosis. RESULTS: In 186 (88.5 %) of the 210 aneurysms that showed filling of the sac with contrast, complete occlusion was observed on follow-up imaging studies at 6 months. Multiple logistic regression analysis indicated that progressive thrombosis was linked to aneurysmal neck diameter ≤4 mm (p < 0.001) and packing density >30 % (p = 0.016). Aneurysms originating from non-branching vessels were of marginal statistical significance (p = 0.056). In 179 progressively thrombosed aneurysms with follow-up evaluations of ≥12 months (mean, 31.9 ± 7.6 months), 168 aneurysms (93.9 %) exhibited stable occlusion, whereas minor recanalization was observed in 6 (3.3 %) instances, and major recanalization occurred in 5 (2.8 %). CONCLUSIONS: In aneurysms where filling of the sac with contrast was demonstrable after coil embolization, aneurysms with small neck diameters or high coil packing density, and non-branching aneurysms seem predisposed to progressive intra-aneurysmal thrombosis over the course of time.

Evaluation of the degree of arteriovenous shunting in intracranial arteriovenous malformations using pseudo-continuous arterial spin labeling magnetic resonance imaging.

INTRODUCTION: Intracranial arteriovenous malformations (AVMs) display venous signals on arterial spin labeling (ASL) magnetic resonance (MR) imaging due to the presence of arteriovenous shunting. Our aim was to quantitatively correlate AVM signal intensity on ASL with the degree of arteriovenous shunting estimated on digital subtraction angiography (DSA) in AVMs. METHODS: MR imaging including pseudo-continuous ASL at 3 T and DSA were obtained on the same day in 40 patients with intracranial AVMs. Two reviewers assessed the nidus and venous signal intensities on ASL images to determine the presence of arteriovenous shunting. Interobserver agreement on ASL between the reviewers was determined. ASL signal intensity of the AVM lesion was correlated with AVM size and the time difference between normal and AVM venous transit times measured from the DSA images. RESULTS: Interobserver agreement between two reviewers for nidus and venous signal intensities was excellent (κ = 0.80 and 1.0, respectively). Interobserver agreement regarding the presence of arteriovenous shunting was perfect (κ = 1.0). AVM signal intensity showed a positive relationship with the time difference between normal and AVM venous transit times (r = 0.638, P < 0.001). AVM signal intensity also demonstrated a positive relationship with AVM size (r = 0.561, P < 0.001). CONCLUSION: AVM signal intensity on ASL in patients with AVM correlates well with the degree of early vein opacification on DSA, which corresponds to the degree of arteriovenous shunting.

Malignant glioma: MR imaging by using 5-aminolevulinic acid in an animal model.

PURPOSE: To evaluate the use of 5-aminolevulinic acid (5-ALA) for the noninvasive detection of malignant gliomas by using in vivo magnetic resonance (MR) imaging in a mouse brain tumor model. MATERIALS AND METHODS: The experiments were animal care committee approved. U-87 glioblastoma cells were exposed to 5-ALA (500 µmol/L) for 6 hours, cells were harvested, and intracellular concentrations of iron, heme, protoporphyrin IX, and ferrochelatase were measured (six in each group). BALB/c nude mice (n = 10) were inoculated with U-87 glioma cells to produce orthotopic brain tumors. T2-weighted imaging was performed 3 weeks after inoculation, and T2* maps were created with a 7-T MR imager before and 24 hours after oral administration of 5-ALA (0.1 mg/g of body weight; n = 6) or normal saline (n = 4). Intratumoral iron concentrations were measured with laser ablation inductively coupled plasma mass spectrometry. For in vitro experiments, differences in the measured data were assessed by using the Mann-Whitney U test with Bonferroni correction. For the in vivo studies, differences in T2* values and iron concentrations of the tumors in the 5-ALA and control groups were assessed by using the Mann-Whitney U test. RESULTS: The intracellular concentration of heme and iron was increased at both 24 and 48 hours after 5-ALA exposure (P = .004). 5-ALA promoted expression of ferrochelatase in glioblastoma cells at both 24 and 48 hours after 5-ALA exposure compared with that at 1 hour (P = .004). In vivo MR imaging revealed a lower median T2* value in glioblastomas treated with 5-ALA compared with those in control mice (14.0 msec [interquartile range, 13.0-14.5 msec] vs 21.9 msec [interquartile range, 19.6-23.2 msec]; P = .011), and laser ablation inductively coupled plasma mass spectrometry revealed that iron concentrations were increased in glioblastomas from the 5-ALA group. CONCLUSION: Administration of 5-ALA increased the intracellular iron concentration of glioblastomas by promoting the synthesis of heme, which is the metabolite of 5-ALA. Because intracellular iron can be detected at MR imaging, 5-ALA may aid in the identification of high-grade foci in gliomas.

Modified protection using far proximal portion of self-expandable closed-cell stents for embolization of wide-necked intracranial aneurysms.

INTRODUCTION: Stent-assisted embolization is sometimes limited in wide-necked aneurysms involving the acute-angled origins of tortuous branching arteries, and occasionally, Y-shaped stenting is required to remedy the sweeping effects of a broad aneurysmal neck on arterial branches. Described herein is a modified stent-assisted coil embolization technique entailing strategic placement of far proximal stent ("distal stenting") as an alternate approach in such scenarios. METHODS: For this particular technique, stent placement is confined to a branch artery, allowing far proximal stent to cover aneurysmal neck, with no bridge to parent artery. Kinking of stents deployed in tortuous arteries is thereby avoided, and better coverage of aneurysmal neck is achieved, compared with traditional stent protection. Records of 12 consecutive patients with wide-necked aneurysms, all treated by coil embolization with distal stenting between January 2009 and February 2014, were retrieved from a prospective data repository at our institution. Outcomes were analyzed in terms of morphologic features and clinical status. RESULTS: This modified technique was largely applied to aneurysms of middle cerebral artery, followed by posterior communicating artery and anterior communicating artery sites. With one exception, all aneurysms treated were successfully occluded. There were no complications directly related to distal stenting. At final follow-up (mean interval, 16.8 ± 9.7 months), complete aneurysmal occlusion was sustained in 81.8%. Delayed stent migration was observed in one patient (8.3%). CONCLUSION: Our study suggests that distal stenting in wide-necked aneurysms is a reasonable alternative to traditional stent protection, despite the potential for delayed stent migration.

Microguidewire protection of wide-necked aneurysms incorporating orifices of tortuous acute-angled vessels: a novel approach.

INTRODUCTION: Protective/remodeling techniques for treating wide-necked intracranial aneurysms are constantly sought. However, their utility may be limited in lesions that incorporate the orifice of acute-angled efferent branch vessels. Furthermore, passage of a protective microcatheter may be challenging if a small branch is extremely tortuous. This study was conducted to explore a novel method of treating wide-necked aneurysms, utilizing microguidewire protection. METHODS: A microcatheter is first passed into parent artery (proximal to aneurysm) to position a microguidewire proximally in the involved branch. A second microcatheter is then inserted into aneurysmal sac. Advancement of the first microcatheter forces the microguidewire to shift, thus covering aneurysmal neck. A framing coil may then be placed within aneurysmal sac, under microguidewire protection. After completing initial coil insertion, easing of tension on the microcatheter allows separation of protective microguidewire and frame coil, confirming stability of the initial coil. RESULTS: This technique was applied to 11 intracranial saccular aneurysms of M1 segment (n=6), middle cerebral artery bifurcation (n=4), and anterior communicating artery (n=1) with success, combining stent protection in two patients. Coil embolization was thus facilitated, resulting in excellent outcomes for all patients. No morbidity or mortality was directly related to microguidewire protection. CONCLUSION: Our small study suggests that microguidewire protection may be a safe alternative, if traditional remodeling or protective options are infeasible due to intrinsic vascular properties. This technique is particularly suited for treatment of wide-necked aneurysms where passage of protective microcatheters into involved branches is not achievable.

Endovascular treatment for superior cerebellar artery aneurysms: morphological features, technique, and outcome.

INTRODUCTION: Superior cerebellar artery (SCA) aneurysms have distinctive morphologic configurations and vascular origins. Herein, we have analyzed the angioarchitectural characteristics of SCA aneurysms and outcomes achieved through endovascular treatment. METHODS: Data accruing prospectively from January, 2002 to September, 2013 yielded 53 SCA aneurysms in 53 patients. Each lesion was classified as either basilar artery (BA), BA-SCA, or SCA type, according to the nature of incorporated vasculature. Clinical and morphologic outcomes were assessed, with emphasis on technical aspects of treatment. RESULTS: Angles formed by SCA and posterior cerebral artery were obtuse (124.8 ± 29.1°) on sides ipsilateral to aneurysms, differing significantly from contralateral counterparts (44.8 ± 22.0°) (p<0.001). The most common type of aneurysm was BA-SCA (54.7 %), followed by SCA (28.3 %) and BA (17.0 %), and BA type aneurysms were the largest in size. Steam-shaped S-configured microcatheters (n=19, 67.9 %) facilitated aneurysm selection for approach via contralateral vertebral artery (n=28), whereas pre-shaped 45/90/J microcatheters (n=21, 84.0 %) primarily were used for ipsilateral vertebral artery approach (n=25). Single-microcatheter technique (52.8 %) was most often applied, followed by double-microcatheter (34.0 %), stent-assisted (9.4 %), and microcatheter-protection techniques (3.8 %). Aneurysmal occlusion was satisfactorily achieved in 45 lesions (82.1 %), with no procedure-related morbidity and mortality. In follow-up monitoring of 46 patients for a mean period of 25.8 ± 24.4 months, only a single instance of major recanalization (2.2 %) occurred. CONCLUSION: Coil embolization of SCA aneurysms is a safe and effective treatment modality, enabling individualized procedural strategies to accommodate distinctive angio-anatomic configurations.

Coil embolization in precommunicating (A1) segment aneurysms of anterior cerebral artery.

INTRODUCTION: Precommunicating (A1) segment aneurysms of the anterior cerebral artery are rare and often pose technical challenges for coil embolization due to their distinctive configurations. Clinical and radiologic outcomes of treating such aneurysms through endovascular coil embolization are presented herein. METHODS: Data accruing prospectively from May 2002 to August 2013 yielded 48 patients harboring 50 A1 segment aneurysms, each classified as proximal, middle, or distal by location. Clinical outcome of the patients and morphological outcome of the aneurysms were assessed, with emphasis on technical aspects of treatment. RESULTS: The aneurysms studied occupied either proximal (n = 39), middle (n = 6), or distal (n = 5). Proximal aneurysms were largely directed posteriorly (80 %), and most (97 %) were devoid of branches. Middle and distal aneurysms were associated with the medial lenticulostriate artery, cortical branches, or fenestrations. The preshaped "S" and steam-shaped "S" microcatheters facilitated aneurysm selection in 60 % of lesions. Single-microcatheter technique was most commonly applied for coil embolization (62 %), followed by balloon protection (16 %). Successful aneurysmal occlusion could be achieved in 76 % of the patients, with no procedure-related morbidity and mortality. At final follow-up (mean interval, 29.9 months), stable aneurysmal occlusion was sustained in 93 % of the patients (40/43). CONCLUSION: A1 segment aneurysms are amenable to safe and efficacious endovascular coil embolization by adjusting procedural strategy to accommodate distinctive anatomic configurations.

Coil embolization of intracranial saccular aneurysms using the Low-profile Visualized Intraluminal Support (LVIS™) device.

INTRODUCTION: The novel Low-profile Visualized Intraluminal Support (LVIS™, LVIS and LVIS Jr.) device was recently introduced for stent-supported coil embolization of intracranial aneurysms. Periprocedural and midterm follow-up results for its use in stent-supported coil embolization of unruptured aneurysms are presented herein. METHODS: In this prospective multicenter study, clinical and radiologic outcomes were analyzed for 55 patients with saccular aneurysms undergoing LVIS-assisted coil embolization between October 2012 and February 2013. Magnetic resonance angiography or digital subtraction angiography was performed to evaluate midterm follow-up results. RESULTS: The standard LVIS device, deployed in 27 patients, was more often used in internal carotid artery (ICA) aneurysms (n=19), whereas the LVIS Jr. (a lower profile stent, n=28) was generally reserved for anterior communicating artery (n=14) and middle cerebral artery (n=8) aneurysms. With LVIS-assisted coil embolization, successful occlusion was achieved in 45 aneurysms (81.8 %). Although no instances of navigation failure or stent malposition occurred, segmentally incomplete stent expansion was seen in five patients where the higher profile LVIS was applied to ICA including carotid siphon. Procedural morbidity was low (2/55, 3.6 %), limited to symptomatic thromboembolism. In the imaging of lesions (54/55, 98.2 %) at 6-month follow-up, only a single instances of major recanalization (1.9 %) occurred. Follow-up angiography of 30 aneurysms (54.5 %) demonstrated in-stent stenosis in 26 (86.7 %), with no instances of stent migration. Only one patient suffered late delayed infarction (modified Rankin Scale 1). CONCLUSION: The LVIS device performed acceptably in stent-assisted coil embolization of non-ruptured aneurysms due to easy navigation and precise placement, although segmentally incomplete stent expansion and delayed in-stent stenosis were issues.